| Does
it really exist a vaccine against the Leishmaniasis ???
Realmente existe una vacuna contra la Leishmaniasis ???
Data-Médicos
Dermagic/Express No. 5-(118)
28 Febrero 2.003 / 28 February 2.003
 Cutaneous
Leishmaniasis Pentamidine e itraconazole.
(hot link)
EDITORIAL ESPAÑOL
=================
Hola amigos de la red, DERMAGIC de nuevo con ustedes, después de vivir
una situación difícil en Venezuela durante los meses de DICIEMBRE Y
ENERO, la cual retardo la presente publicación sobre LEISHMANIASIS Y
VACUNAS
Puedo comentarles mi experiencia con un caso de Leishmanisis cutánea que
tuve la oportunidad de ver en mi consulta, el paciente un joven de 16
años quien referí al Hospital Central de Maracay, allí se le comenzó a
practicar inmunoterapia (BCG mas formas amastigostas de Leishmania), el
paciente no respondió al tratamiento y tuvo que ser tratado con el
clásico tratamiento de 3 ciclos de 20 ampollas de glucantime via
intramuscular.
Este evento me llevo a realizar la presente revisión, para evaluar las
diferentes metodologías existentes para elaborar una vacuna contra esta
enfermedad.
Se ha dicho mucho sobre la LEISHMANIASIS, enfermedad parasitaria con
tres variantes, CUTÁNEA, CUTÁNEO MUCOSA, Y VISCERAL (KALA-AZAR). En el
mundo se producen aproximadamente 15 millones casos nuevos al año con
unas 500.000 mil muertes anuales entre niños y adultos.
Numerosos países alrededor del mundo se han dedicado a la dura tarea de
fabricar una VACUNA EFICAZ contra la enfermedad, entre ellos Venezuela. Encontré muchas referencias BIBLIOGRAFICAS, de muchos
países, diferentes
métodos y diferentes estudios TODOS ellos con relativo éxito para
encontrar una VACUNA tanto para la LEISHMANIASIS CUTÁNEA, MUCOSA y
VISCERAL. La mayoría de estos métodos son muy parecidos en su esencia;
combinación de formas amastigotas de diferentes cepas de Leishmania mas
BCG (bacilo de Calmette Guerin), en forma de inmunoterapia, y también
vacunas en base a ADN y anfígenos de Leishmania.
El único trabajo o estudio que en esencia se diferencia a los "clásicos"
ya mencionados es el del Dr. Valenzuela y Dr. Ribeiro de la Universidad de
Bethesda USA año 2.001 Agosto 6, quienes logran aislar una proteína de
la saliva de de la mosca de arena (sand fly) flebótomo papatasi, quien es
el encargado de transmitir y diseminar la Leishmaniasis mayor en el
Medio Oriente.
Con esta proteína, que denominaron SP15 construyeron una
vacuna en base a ADN, que que utilizaron para inmunizar ratones. Cuando
los ratones fueron inyectados posteriormente con parásitos de Leishmania
mayor mezclados con la saliva de la mosca, la infección fue marcadamente
menor comparada con la infección en ratones no vacunados. Las Lesiones
en los ratones vacunados fueron mucho menores y desaparecieron en seis
(6) semanas. Los ratones no vacunados desarrollaron grandes ulceras y no
eliminaron el parasito.
Otro aspecto a resaltar es la DONACIÓN DE NUESTRO querido amigo BILL
GATES Y SU ESPOSA Melinda de 15. millones de dólares a través de una
fundación, para el desarrollo de una vacuna contra la LEISHMANIASIS a la
compañía CORIXA, quien en base a nuevos anfígenos realizo en el año
2.001 los primeros estudios de campo en BRASIL.
Grandes esfuerzos de todos estos investigadores, los FELICITO a todos
por su colaboración a la salud de NUESTRA bella población HUMANA.
Grandes esfuerzos que espero sean recompensados pronto con la salida al
MERCADO de una VACUNA contra esta enfermedad, pues según lo revisado
TODAVÍA no EXISTE UNA VACUNA COMO TAL disponible comercialmente contra
la LEISHMANIASIS.
Los hechos en esta apocalíptica revisión con mas de 100 referencias
bibliograficas
Saludos a Todos
Dr. José Lapenta R.
ENGLISH EDITORIAL
=================
Hello friends of the net, DERMAGIC again with
you, after living a difficult situation in Venezuela during the months of
DECEMBER AND JANUARY, which I stop the present publication LEISHMANIASIS AND
VACCINES.
I can comment them my experience with a case of cutaneous Leishmanisis that I
had the opportunity to see in my office, the patient a 16 year-old boy who I
referred to the Central Hospital of Maracay, there he was begun to practice
immunotherapy (BCG -Calmette-Guerin- plus amastigotes forms of Leishmania), the
patient didn't respond to the treatment and he had to be treated with the
classic treatment of 3 cycles of 20 glucantime amps (chemotherapy) via IM.
This event takes myself to carry out the present revision, to evaluate the
different existent methodologies to elaborate a vaccine against this illness.
A lot of things about LEISHMANIASIS has been said, parasitic illness with three
variants, CUTANEOUS, MUCOUS, AND VISCERAL (KALA-AZAR). In the world they take
place 15 millions new cases approximately a year with some 500.000 thousand
annual deaths between children and adults.
Numerous countries around the world have been devoted to the hard task of
manufacturing an EFFECTIVE VACCINE against the illness, among them Venezuela, I
found many BIBLIOGRAPHICAL references, of many countries, different methods and
different studies ALL them with relative success to find a VACCINE for the
CUTANEOUS, MUCOUS and VISCERAL LEISHMANIASIS. Most of these methods are very
similar in their essence: combination of amastigotes different strains of
Leishmania plus BCG (calmette Guerin bacillus), in immunotherapy form, and also
VACCINES based on DNA and antigens of Leishmania.
The only work or study that differs to those in essence "classic" already
mentioned it is that of the Dr Valenzuela and Dr Ribeiro of the University of
Bethesda USA year 2.001 August 6 who are able to isolate a protein of the saliva
of of the fly of sand (sand fly) phlebotomus papatasi who is the one in charge
of to transmit and to disseminate the Leishmaniasis major in the Middle East.
With this protein that SP15 denominated they built a vaccine based on DNA that
used to immunize mice. When the mice were injected later on with parasites of
Leishmania adult mixed with the saliva of the fly, the infection was markedly
minor compared with the infection in not vaccinated mice. The Lesions in the
vaccinated mice were much smaller and they disappeared in six (6) weeks. The not
vaccinated mice developed big ulcers and they didn't eliminate the parasite.
Another aspect to stand out is that OUR dear friend BILL GATES AND ITS WIFE
Melinda they made a DONATION of 15 millions of dollars through a foundation, for
the development of a vaccine against the LEISHMANIASIS to the company CORIXA who
I carry out in the year 2.001 the first trail field studies in BRAZIL, based on
novel antigens.
All these investigators' big efforts, I CONGRATULATE them to all for their
collaboration to OUR beautiful HUMAN population's health. Big efforts that I
wait are rewarded soon with the release to the MARKET of a VACCINE against this
illness, because according to that revised A VACCINE it doesn't STILL EXIST
commercially available one against the LEISHMANIASIS
The facts in this apocalyptic revision with but of 100 bibliographical
references
Greetings to All
Dr José Lapenta R.
===========================================================
REFERENCIAS BIBLIOGRAFICAS /BIBLIOGRAPHICAL REFERENCES
===========================================================
1.) Vaccination against Leishmania infections.
2.) Leishmania transmission-blocking vaccines: a review.
3.) Vaccination against cutaneous leishmaniasis: current status.
4.) Leishmaniasis: current status of vaccine development.
5.) Protective immunity against cutaneous leishmaniasis achieved by partly
purified vaccine in a volunteer.
6.) Vaccines against leishmaniasis.
7.) Mechanisms of acquired immunity in leishmaniasis.
8.) Experimental leishmaniasis in humans: review.
9.) Heterologous protection in murine cutaneous leishmaniasis.
10.) IgE antibody against surface antigens of Leishmania promastigotes in
American cutaneous leishmaniasis.
11.) A comparison of the molecular biology of trypanosomes and leishmaniae, and
its impact on the development of methods for the diagnosis and vaccination of
leishmaniasis and Chagas disease.
12.) Dendritic cell-based vaccination strategies: induction of protective
immunity against leishmaniasis.
13.) Effective immunization against cutaneous leishmaniasis with defined
membrane antigens reconstituted into liposomes.
14.) [An immunologic method of producing antigens for the treatment and
prevention of leishmaniasis]
15.) Development of vaccines against leishmaniasis.
16.) Further trials of a vaccine against American cutaneous leishmaniasis.
17.) Vaccination against cutaneous leishmaniasis in mice using nonpathogenic
cloned promastigotes of Leishmania major and importance of route of injection.
18.) Leishmaniasis.
19.) Leishmania (Leishmania) amazonensis-induced cutaneous leishmaniasis in the
primate Cebus apella: a model for vaccine trials.
20.) [Experimental skin leishmaniasis: II--course of the infection in the Cebus
apella primate (Cebidae) caused by Leishmania (V.) braziliensis and L. (L.)
amazonensis]
21.) Leishmania (Leishmania) major-infected rhesus macaques (Macaca mulatta)
develop varying levels of resistance against homologous re-infections.
22.) Protection of C57BL/10 mice by vaccination with association of purified
proteins from Leishmania (Leishmania) amazonensis.
23.) Experimental cutaneous leishmaniasis. IV. The humoral response of Cebus
apella (Primates: Cebidae) to infections of Leishmania (Leishmania) amazonensis,
L. (Viannia) lainsoni and L. (V.) braziliensis using the direct agglutination
test.
24.) Vaccination of C57BL/10 mice against cutaneous Leishmaniasis using killed
promastigotes of different strains and species of Leishmania.
25.) [Experimental cutaneous leishmaniasis: I--on the susceptibility of the
primate Cebus apella (Cebidae) to the infection caused by Leishmania (Viannia)
lainsoni Silveira, Shaw and Ishikawa, 1987]
26.) [Experimental cutaneous leishmaniasis. III. Histopathological aspects of
the developmental behavior of the cutaneous lesion induced in Cebus apella
(Primates: Cebidae) by Leishmania (Viannia) lainsoni, L. (V.) braziliensis and
L. (Leishmania) amazonensis]
27.) Immune responses induced by a Leishmania (Leishmania) amazonensis
recombinant antigen in mice and lymphocytes from vaccinated subjects.
27A.) Vervet monkeys vaccinated with killed Leishmania major parasites and
interleukin-12 develop a type 1 immune response but are not protected against
challenge infection.
28.) Protective immunity using recombinant human IL-12 and alum as adjuvants in
a primate model of cutaneous leishmaniasis.
29.) Leishmaniasis in Brazil: XII. Observations on cross-immunity in monkeys and
man infected with Leishmania mexicana mexicana, L. m. amazonensis, L.
braziliensis braziliensis, L. b. guyanensis and L. b. panamensis.
30.) Leishmania pifanoi amastigote antigens protect mice against cutaneous
leishmaniasis.
31.) Specific immunization of mice against Leishmania mexicana amazonensis using
solubilized promastigotes.
32.) Membrane glycoprotein M-2 protects against Leishmania amazonensis
infection.
33.) The role of BCG in human immune responses induced by multiple injections of
autoclaved Leishmania major as a candidate vaccine against leishmaniasis.
34.) Randomised vaccine trial of single dose of killed Leishmania major plus BCG
against anthroponotic cutaneous leishmaniasis in Bam, Iran.
35.) A randomised, double-blind, controlled trial of a killed L. major vaccine
plus BCG against zoonotic cutaneous leishmaniasis in Iran.
36.) Immunogenicity and safety of autoclaved Leishmania major plus BCG vaccine
in healthy Sudanese volunteers.
37.) Immune responses in vaccinated dogs with autoclaved Leishmania major
promastigotes.
38.) Study of the safety, immunogenicity and efficacy of attenuated and killed
Leishmania (Leishmania) major vaccines in a rhesus monkey (Macaca mulatta) model
of the human disease.
39.) Safety and immunogenicity of a killed Leishmania (L.) amazonensis vaccine
against cutaneous leishmaniasis in Colombia: a randomized controlled trial.
40.) Immune response in healthy volunteers vaccinated with killed leishmanial
promastigotes plus BCG. I: Skin-test reactivity, T-cell proliferation and
interferon-gamma production.
41.) The effect of repeated leishmanin skin testing on the immune responses to
Leishmania antigen in healthy volunteers.
42.) Evaluation of the stability and immunogenicity of autoclaved and
nonautoclaved preparations of a vaccine against American tegumentary
leishmaniasis.
43.) A randomized double-blind placebo-controlled trial to evaluate the
immunogenicity of a candidate vaccine against American tegumentary
leishmaniasis.
44.) BCG expressing LCR1 of Leishmania chagasi induces protective immunity in
susceptible mice.
45.) Immune response in healthy volunteers vaccinated with BCG plus killed
leishmanial promastigotes: antibody responses to mycobacterial and leishmanial
antigens.
46.) Immunotherapy with live BCG plus heat killed Leishmania induces a T helper
1-like response in American cutaneous leishmaniasis patients.
47.) Vaccination of mice with a combination of BCG and killed Leishmania
promastigotes reduces acute Trypanosoma cruzi infection by promoting an
IFN-gamma response.
48.) Immunization of BALB/c mice with mIFN-gamma-secreting Mycobacterium bovis
BCG provides early protection against Leishmania major infection.
49.) Short report: evaluation of the potency and stability of a candidate
vaccine against American cutaneous leishmaniasis.
50.) The immunology of susceptibility and resistance to Leishmania major in
mice.
51.) Optimization of DNA vaccination against cutaneous leishmaniasis.
52.) Canine leishmaniasis: epidemiological risk and the experimental model.
53.) Protective efficacy of a tandemly linked, multi-subunit recombinant
leishmanial vaccine (Leish-111f) formulated in MPL adjuvant.
54.) Molecular biological applications in the diagnosis and control of
leishmaniasis and parasite identification.
55.) Immunochemotherapy in American cutaneous leishmaniasis: immunological
aspects before and after treatment.
56.) T cell responses to crude and defined leishmanial antigens in patients from
the lower Amazon region of Brazil infected with different species of Leishmania
of the subgenera Leishmania and Viannia.
57.) Cell-mediated immunity in localized cutaneous leishmaniasis patients before
and after treatment with immunotherapy or chemotherapy.
58.) Immunotherapy as a treatment of American cutaneous leishmaniasis:
preliminary studies in Brazil.
59.) T-cell responsiveness of American cutaneous leishmaniasis patients to
purified Leishmania pifanoi amastigote antigens and Leishmania braziliensis
promastigote antigens: immunologic patterns associated with cure.
60.) Dichotomy of the T cell response to Leishmania antigens in patients
suffering from cutaneous leishmaniasis; absence or scarcity of Th1 activity is
associated with severe infections.
61.) Chemotherapy for cutaneous leishmaniasis: a controlled trial using killed
Leishmania (Leishmania) amazonensis vaccine plus antimonial.
62.) Immunotherapy versus chemotherapy in localised cutaneous leishmaniasis.
63.)Immunotherapy of localized, intermediate, and diffuse forms of American
cutaneous leishmaniasis.
64.) Characterization of the immune response in subjects with self-healing
cutaneous leishmaniasis.
65.) Antigen provoking gamma interferon production in response to Mycobacterium
bovis BCG and functional difference in T-cell responses to this antigen between
viable and killed BCG-immunized mice.
66.) Autoclaved Leishmania major vaccine for prevention of visceral
leishmaniasis: a randomised, double-blind, BCG-controlled trial in Sudan.
67.) Leishmania donovani p36(LACK) DNA vaccine is highly immunogenic but not
protective against experimental visceral leishmaniasis.
68.) Vaccination of Balb/c mice against experimental visceral leishmaniasis with
the GP36 glycoprotein antigen of Leishmania donovani.
69.) Vaccination of langur monkeys (Presbytis entellus) against Leishmania
donovani with autoclaved L. major plus BCG.
70.) Successful vaccination against Leishmania donovani infection in Indian
langur using alum-precipitated autoclaved Leishmania major with BCG.
71.) [Protective effects of leishmanial antigens against Leishmania infantum
infection in Lagurus lagurus]
72.) Vaccination with DNA encoding ORFF antigen confers protective immunity in
mice infected with Leishmania donovani.
73.) Intradermal infection model for pathogenesis and vaccine studies of murine
visceral leishmaniasis.
74.) Saponins, IL12 and BCG adjuvant in the FML-vaccine formulation against
murine visceral leishmaniasis.
75.) COMPONENT OF FLY SALIVA MAKES PROMISING LEISHMANIASIS VACCINE
76.) Effort to Target Clinical Development of Corixa's Leishmaniasis Vaccine
77.) Report on the fourth TDR/IDRI meeting on second generation vaccine against
Leishmaniasis. Merida, Yucatan, Mexico, May 1-3, 2001.
78.) Drug development: LEISHMANIASIS
79.) Vaccines for cutaneous leishmaniasis
80.) Vaccine development: LEISHMANIASIS
81.) Vaccine from fly spit
82.)Toward a defined anti-Leishmania vaccine targeting vector antigens:
characterization of a protective salivary protein.
83.) Other studies and Bibliographical references
====================================================
====================================================
1.) Vaccination against Leishmania infections.
====================================================
Curr Drug Targets Immune Endocr Metabol Disord 2002 Oct;2(3):201-26
Mauel J.
Institute of Biochemistry, Ch. des Boveresses 155, CH-1066 Epalinges,
Switzerland. [email protected]
Leishmaniasis, that affects millions of people worldwide, is an infectious
disease caused by the protozoan parasite Leishmania. Incidence of the condition
appears to be increasing in several parts of the world. Of the three main
presentations of the disease, i.e. cutaneous, mucocutaneous and visceral, only
the first one tends to heal spontaneously, while the other two are considered
fatal if left to run their natural course. Recovery from leishmaniasis, whether
spontaneous or drug-induced, is usually accompanied by solid immunity against
reinfection, which provides a rationale for attempting to design vaccines
against the disease. This review presents an outline of the main immunological
features of Leishmania infections and of the mechanisms thought to operate in
recovery from the disease. It describes various experimental approaches to
vaccination in man and animal models, including the use of virulent and
avirulent organisms, of dead parasites and extracts thereof, and of purified
parasite proteins. Assays using novel technologies, such as the direct injection
of DNAs encoding parasite proteins, or the inoculation of viral or bacterial
vectors expressing such molecules, as well as recent experiments aimed at
inducing an immune response against saliva of the insect vector, are also
reviewed. Observations made during the course of these studies have reinforced
the notion that vaccination against leishmaniasis is indeed feasible. However,
in spite of intensive efforts by many groups and many reports of success in man
and in animal models, a consensus is yet to emerge as to what constitutes the
best approach to vaccination against leishmaniasis.
====================================================
2.) Leishmania transmission-blocking vaccines: a review.
====================================================
East Afr Med J 1999 Feb;76(2):93-6
Tonui WK.
Centre for Biotechnology Research and Development, Kenya Medical Research
Institute, Nairobi.
OBJECTIVE: To review information on transmission-blocking vaccine against
Leishmania infections. DATA SOURCES: Peer-reviewed journals and accepted
manuscripts in press. STUDY SELECTION: Laboratory studies based on raising of
immune sera against Leishmania-derived antigens using the BALB/c and hamster
murine models. Testing of the immune sera for their potential to limit the
transmission of cutaneous leishmaniasis in its natural vector Phlebotomus
duboscqi. DATA SYNTHESIS: Leishmania major-derived recombinant 63 kilodalton
glycoprotein (rgp63), lipophosphoglycan (LPG), whole parasite, flagella and
nuclear fractions; monoclonal antibodies and sandfly gut antigens have all been
tested for their candidacy as Leishmania-transmission blocking vaccines.
CONCLUSION: Liposphoglycan proved to be a promising candidate for Leishmania
transmission-blocking vaccine studies.
====================================================
3.) Vaccination against cutaneous leishmaniasis: current status.
====================================================
Am J Clin Dermatol 2002;3(8):557-70
Melby PC.
Department of Veterans Affairs Medical Center, Medical Service, South Texas
Veterans Health Care System, San Antonio, TX 78229, USA. [email protected]
The different cutaneous leishmaniases are distinct in their etiology,
epidemiology, transmission, and geographical distribution. In most instances
cutaneous leishmaniasis is limited to one or a few skin ulcers that develop at
the site where the parasites were deposited during the bite of the sandfly
vector. Lesions typically heal spontaneously after several months but some
lesions can be large and follow a chronic, more severe course. Protective
immunity is usually acquired following cutaneous infection with Leishmania spp.,
so prevention of disease through prophylactic immunization appears to be
feasible. Since vaccination with live, virulent parasites is associated with an
unacceptable rate of adverse events, attention has turned to the use of killed
or attenuated parasite vaccines and defined subunit vaccines. Whole parasite
vaccines have the advantage of delivering multiple antigenic epitopes that may
be necessary for initiation of a broad-based immune response. Persistent or
repeated immune-stimulation by parasite antigens and/or sustained expression of
interleukin-12 appear to be critical elements in the development of durable
immunity. A number of purified or recombinant antigens, when co-administered
with a vaccine adjuvant, appear promising as vaccine candidates against
cutaneous leishmaniasis. The sustained expression of recombinant Leishmania
antigens by vaccination with DNA is an attractive approach because it mimics the
persistent antigenic stimulation of subclinical infection. Effective
vaccine-induced immunity must generate an antigen-specific memory T cell
population that, upon exposure to the infecting parasite, rapidly produces a
type 1 effector T cell response that leads to interferon-gamma-mediated
activation of infected macrophages to kill the intracellular parasites. This
parasite-directed recall response must be prompt and of sufficient magnitude to
overcome the subversive effect that the intracellular infection has on
macrophage effector function. It is unlikely that vaccination against cutaneous
leishmaniasis would induce sterile immunity, but a small number of parasites are
likely to persist subclinically.
====================================================
4.) Leishmaniasis: current status of vaccine development.
====================================================
Clin Microbiol Rev 2001 Apr;14(2):229-43
Handman E.
Infection and Immunity Division, The Walter and Eliza Hall Institute of Medical
Research, The Royal Melbourne Hospital, Parkville 3050, Australia.
[email protected]
Leishmaniae are obligatory intracellular protozoa in mononuclear phagocytes.
They cause a spectrum of diseases, ranging in severity from spontaneously
healing skin lesions to fatal visceral disease. Worldwide, there are 2 million
new cases each year and 1/10 of the world's population is at risk of infection.
To date, there are no vaccines against leishmaniasis and control measures rely
on chemotherapy to alleviate disease and on vector control to reduce
transmission. However, a major vaccine development program aimed initially at
cutaneous leishmaniasis is under way. Studies in animal models and humans are
evaluating the potential of genetically modified live attenuated vaccines, as
well as a variety of recombinant antigens or the DNA encoding them. The program
also focuses on new adjuvants, including cytokines, and delivery systems to
target the T helper type 1 immune responses required for the elimination of this
intracellular organism. The availability, in the near future, of the DNA
sequences of the human and Leishmania genomes will extend the vaccine program.
New vaccine candidates such as parasite virulence factors will be identified.
Host susceptibility genes will be mapped to allow the vaccine to be targeted to
the population most in need of protection.
====================================================
5.) Protective immunity against cutaneous leishmaniasis achieved by partly
purified vaccine in a volunteer.
====================================================
Lancet 1986 Jun 28;1(8496):1490
Monjour L, Monjour E, Vouldoukis I, Ogunkolade BW, Frommel D.
Publication Types:
Letter
====================================================
====================================================
6.) Vaccines against leishmaniasis.
====================================================
Ann Trop Med Parasitol 1995 Dec;89 Suppl 1:83-8
Modabber F.
UNDP/World Bank/WHO Special Programme for Research and Training in Tropical
Diseases, World Health Organization, Geneva, Switzerland.
Unlike some other parasites, Leishmania can be grown in cell-free media with
ease. This simple cultivation and the use of killed parasites as skin-test
antigens (leishmanin) for diagnosis in humans during the past several decades
have prompted scientists to try using the killed parasites, with or without
adjuvant, as vaccines or for immunotherapy. In addition, different recombinant
molecules, either parasite fractions or genetically engineered organisms (i.e.
Leishmania made avirulent by removing specific genes, or bacteria carrying and
expressing leishmanial genes), are being investigated as potential future
vaccines against leishmaniasis. The 'first-generation' vaccines, composed of
killed parasites with or without adjuvant, have been derived using an empirical
approach. The 'second-generation' vaccines have been genetically constructed,
using a more rational approach. At present, the first-generation vaccines are at
various stages of Phase I (safety), II (reactivity) or III (efficacy) trials in
humans. Results are expected in 1-2 years. The second-generation vaccines are,
however, only in a preclinical state and are not expected to reach clinical
trials for at least 3 years. The Special Programme for Research and Training in
Tropical Diseases (TDR) is actively involved in most clinical trials of the
first-generation vaccines and supports many of the second-generation candidates.
In the present article, the advantages and disadvantages of each approach to
vaccine development are discussed and the progress being made is briefly
reviewed.
====================================================
7.) Mechanisms of acquired immunity in leishmaniasis.
====================================================
Philos Trans R Soc Lond B Biol Sci 1984 Nov 13;307(1131):87-98
Howard JG, Liew FY.
Self-curing cutaneous leishmaniasis depends on T cell-mediated immune activation
of infected macrophages. Failure of immune control in inbred mouse models of
metastasizing mucocutaneous and visceralizing forms of the disease involves,
respectively, insusceptibility of the parasite and the generation of T cells
that suppress a potentially curative response. Prophylactic immunization in man
has so far been restricted to cutaneous leishmaniasis and based on inducing
infection under controlled conditions with virulent Leishmania tropica major
promastigotes. The feasibility of immunization against visceral leishmaniasis
merits reconsideration. BALB/c mice are genetically vulnerable to L. tropica
major, which produces a fatal visceralizing type of disease involving specific
suppression of cell-mediated immunity. Potent and lasting protection can be
induced by repeated intravenous immunization with irradiated promastigotes. The
efficacy of this 'vaccine' is relatively heat-stable (1 h at 56 degrees C).
Immunity is not attributable to antibody but to the generation of Lyt-1+2- T
cells which, although possessing helper and macrophage-activating functions, do
not express classical delayed-type hypersensitivity. The immunological features
of this system and its relevance to the possibility of protection against human
Leishmania donovani infection are considered.
====================================================
8.) Experimental leishmaniasis in humans: review.
====================================================
Rev Infect Dis 1991 Sep-Oct;13(5):1009-17
Melby PC.
Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious
Diseases, National Institutes of Health, Bethesda, Maryland.
Experimental infection of humans with Leishmania parasites has contributed
significantly to the understanding of the etiology, transmission, and
pathogenesis of leishmaniasis and the immunity associated with it. Leishmania
organisms recovered from human and animal tissue, insect vectors, and in vitro
cultures have all produced cutaneous or visceral leishmaniasis in human subjects
who were voluntarily inoculated with them. Volunteers bitten by infected
Phlebotomine sandflies also developed cutaneous or visceral disease. In these
experiments, it appeared that the parasite must undergo certain developmental
changes within the sandfly for it to become infective and that the parasites in
sandflies were far more efficient in causing full-blown infection than were
cultured Leishmania organisms. The clinical manifestations of these experimental
infections did not differ from infections that were acquired naturally. Natural
or experimental infections appeared to confer resistance to subsequent
leishmanial infection. This immunity was best documented to be a
species-specific phenomenon; however, a small number of studies have
demonstrated cross protection between some Leishmania species. In this review
article, data from human experimental infections are summarized and discussed in
light of recent advances in the field.
====================================================
9.) Heterologous protection in murine cutaneous leishmaniasis.
====================================================
Immunol Cell Biol 1987 Oct;65 Pt 5:387-92
Mitchell GF, Handman E.
Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria,
Australia.
Mice immunized with a glycolipid antigen (GL) of Leishmania major plus adjuvant
are relatively resistant to subsequent infection with this protozoan parasite.
The GL is affinity purified on the monoclonal antibody WIC-79.3 which is L.
major-specific and does not react with L. donovani. When another monoclonal,
WIC-108.3, which cross-reacts with several Leishmania species, is used to
affinity purify GL from L. donovani, the eluted material can partially protect
genetically resistant mice against L. major. Thus, GL cross-reactions may in
part underlie the known protective effects of crude L. donovani antigens against
L. major infection. Experiments with live parasites of the L. major isolate
LRC-L119, that is non-pathogenic in mice, that does not survive long in
macrophages in vitro, and that has not been shown to contain any WIC-79.3
reactive GL, indicated that this isolate will very effectively protect mice
against subsequent infection. This raises the possibility that GL is only one of
at least two different classes of vaccinating antigen capable of protectively
immunizing mice in this cutaneous leishmaniasis model.
====================================================
10.) IgE antibody against surface antigens of Leishmania promastigotes in
American cutaneous leishmaniasis.
====================================================
Parasite Immunol 1986 Mar;8(2):109-16
Lynch NR, Malave C, Turner KJ, Infante B.
As IgE-mediated immune mechanisms participate in the host defence against some
types of parasites, we evaluated sera from American cutaneous leishmaniasis
(ACL) patients for the presence of this antibody against Leishmania. Using
monoclonal antibodies against human IgE and an immunoperoxidase staining
technique, 48% of the patients sera tested were found to contain IgE antibody
that bound strongly to Leishmania promastigotes. A much lower proportion of sera
from non-symptomatic subjects from either endemic or non-endemic areas of the
disease contained significant levels of anti-Leishmania IgE antibody (6.5% and
0% respectively). The results indicated that the IgE antibody bound
predominantly to surface components of the promastigotes, and reactivity against
the intracellular amastigote form of the parasite was rarely detected. Somewhat
unexpectedly, in a small proportion of the sera, the IgE antibody showed
apparent specificity for L. mexicana or L. braziliensis. This study demonstrates
that ACL patients can develop anti-Leishmania IgE antibody responses, that seem
to be directed preferentially against surface antigens of promastigotes, and
that can be strain specific. This raises the question as to the possible
contribution of this antibody to the immune defence mechanisms against the
parasite.
====================================================
11.) A comparison of the molecular biology of trypanosomes and leishmaniae, and
its impact on the development of methods for the diagnosis and vaccination of
leishmaniasis and Chagas disease.
====================================================
Biol Res 1993;26(1-2):219-24
O'Daly JA.
Centro de Microbiologia y Biologia Celular, Instituto Venezolano de
Investigaciones Cientificas (IVIC), Caracas.
Our main interest have focused on Chagas disease and Leishmaniasis, working in
the areas of: 1--The molecular biology of Trypanosomes and Leishmaniae, and
2--The immunology of Chagas disease, cutaneous leishmaniasis and visceral
leishmaniasis. In this article we summarize the work realized in the last 20
years in the Immunobiology Laboratory at the IVIC with special emphasis in the
development of a vaccine against leishmaniasis that is being currently used in a
field trial in human beings of the endemic area of Guatire, Miranda State,
Venezuela.
====================================================
12.) Dendritic cell-based vaccination strategies: induction of protective
immunity against leishmaniasis.
====================================================
Immunobiology 2001 Dec;204(5):659-66
Moll H, Berberich C.
Institute for Molecular Biology of Infectious Diseases, University of Wurzburg,
Germany. [email protected]
The clinical symptoms caused by infections with Leishmania parasites range from
self-healing cutaneous to uncontrolled visceral disease and depend not only on
the parasite species but also on the type of the host's immune response.
Infection of genetically susceptible mice with Leishmania major results in the
development of disease-promoting T helper cells of type 2 (Th2). On the other
hand, healing of lesions is dependent on the induction of Th1 cells producing
interferon-gamma (IFN-gamma). The presence of interleukin 12 (IL-12) is known to
be crucial for the differentiation of Th1 cells. Whereas IL-12 release and the T
cell stimulatory functions of macrophages are down-regulated by L. major
infection, dendritic cells (DC) exposed to L. major readily produce IL-12 and
are highly potent antigen-presenting cells. Moreover, DC pulsed ex vivo with L.
major antigen induce protection in otherwise susceptible mice against subsequent
challenges with the parasites. The protection is long-lasting and correlates
with a shift of the cytokine expression pattern towards a Th1 response. Thus, DC
serve as immunomodulators in vivo and can be used as an effective adjuvant for
vaccination against experimental leishmaniasis. Studies on the ability of DC to
induce protective immunity to leishmaniasis may have important implications for
the development of novel strategies for prophylactic and therapeutic
immunizations against microbial pathogens.
====================================================
13.) Effective immunization against cutaneous leishmaniasis with defined
membrane antigens reconstituted into liposomes.
====================================================
J Immunol 1988 Feb 15;140(4):1274-9 Related Articles, Links
Erratum in:
J Immunol 1988 Apr 15;140(8):2858
Russell DG, Alexander J.
Max-Planck-Institut fur Biologie, Tubingen, Federal Republic of Germany.
The abundant Leishmania promastigote surface Ag gp63 and Leishmania promastigote
lipophosphoglycan were reconstituted into liposomes and used as a vaccine
against the agent of New World cutaneous leishmaniasis, Leishmania mexicana. The
Ag were inoculated s.c., i.p., and i.v. into CBA/ca and BALB/c mice. Even at low
Ag dosages, 8 to 10 micrograms/mouse, the Ag induced appreciable levels of
protection. In CBA/ca mice complete protection was obtained by s.c. inoculation
of antigen-containing liposomes. Protection could be transferred with T cells to
naive mice. Interestingly, the Ag-containing liposomes did not cause the disease
exacerbation observed in previous vaccine studies with crude parasite extracts.
====================================================
14.) [An immunologic method of producing antigens for the treatment and
prevention of leishmaniasis]
====================================================
C R Acad Sci III 1989;308(5):129-34
[Article in French]
Vouldoukis I, Monjour L.
Laboratoire de Parasitologie experimentale et I.N.S.E.R.M. U n. 313, Faculte de
Medecine Pitie-Salpetriere, Paris.
Antigens isolated from lysates of L. infantum promastigotes by electroelution
from polyacrylamide gels and by gel filtration, have already been proven to
induce anti-Leishmania protective immunity in BALB/c mice when injected
subcutaneously. At the present time, five preparations including either
Leishmania antigens or anti-idiotypic reagents as vaccines can be considered as
candidates for immunoprophylaxis in natural hosts of Leishmania parasites. We
present a new method for producing Leishmania antigenic preparations which is of
considerable interest, since it can be proposed for immunotherapy and prevention
of other parasitic, bacterial, viral and perhaps, retroviral diseases.
====================================================
15.) Development of vaccines against leishmaniasis.
====================================================
Scand J Infect Dis Suppl 1990;76:72-8
Modabber F.
UNDP/World Bank/WHO Special Programme for Research and Training in Tropical
Diseases (TDR), Geneva, Switzerland.
A vaccine against leishmaniasis is the only practical means to control this
disease in many epidemiological situations. Two approaches have been adopted:
pragmatic and systematic. The pragmatic approach involves trial of crude
leishmanial components in animals and then in humans if they meet safety
requirements. The systematic approach requires identification of the protective
immunogen(s), appropriate carrier and adjuvant, and determination of the immune
responses and modes of presentation of the immunogens to achieve the desired
effect. Progress have been made with both approaches. Killed Leishmania
promastigotes have been used in Brazil for high risk individuals with
encouraging results. Impressive results have also been observed with killed
Leishmania plus BCG for immunotherapy of cutaneous leishmaniasis in Venezuela.
With the systematic approach, recent research has identified some protective
immunogens, cloned protective murine T-cells, developed primate models
resembling the human disease, cloned and expressed genes of some potential
immunogens, identified some features of the protective immune response,
determined modes of presentation of immunogen to produce a protective response,
and been able to protect mice (even/Balb/c) against L. major infection. The
difficult part that remains is the implementation of a vaccine or any control
measure in the poor communities where they are needed and where the lack of
required infrastructure does not allow adequate coverage.
====================================================
16.) Further trials of a vaccine against American cutaneous leishmaniasis.
====================================================
Trans R Soc Trop Med Hyg 1986;80(6):1001 Related Articles, Links
Mayrink W, Antunes CM, Da Costa CA, Melo MN, Dias M, Michalick MS, Magalhaes PA,
De Oliveira Lima A, Williams P.
Publication Types:
Clinical Trial
Letter
====================================================
====================================================
17.) Vaccination against cutaneous leishmaniasis in mice using nonpathogenic
cloned promastigotes of Leishmania major and importance of route of injection.
====================================================
Aust J Exp Biol Med Sci 1984 Apr;62 ( Pt 2):145-53
Mitchell GF, Handman E, Spithill TW.
In vaccination studies, mice have been injected by different routes with living
promastigotes of nonpathogenic leishmania followed by cutaneous challenge with
pathogenic promastigotes. Parasites used for vaccination have been promastigotes
of the cloned parasite lines A12 and A52 derived from Leishmania major isolate
L137, or long-term cultured promastigotes of the leishmaniasis recidiva isolate,
L32 (L.t.tropica). None of these protozoa causes lesions after cutaneous
injection to mice. Disease in previously injected mice has been monitored after
cutaneous challenge with promastigotes of a virulent cloned line, V121, derived
from isolate L137. Mice used were C57BL/6 (genetically resistant), BALB/c and
BALB/c.H-2b (genetically susceptible) and BALB/c.H-2k (also genetically
susceptible but sometimes less so than BALB/c). C57BL/6 mice were almost
completely resistant to subsequent cutaneous disease when challenged after
intraperitoneal injection of viable nonpathogenic cloned promastigotes. In
contrast, BALB/c, BALB/c.H-2b and BALB/c.H-2k mice challenged after intravenous
or intraperitoneal injection were only protected partially against cutaneous
leishmaniasis. These vaccinated mice generally showed persistent low grade
cutaneous disease for many months after challenge. High doses of viable L32
promastigotes injected intraperitoneally were also able to induce a degree of
resistance to subsequent cutaneous leishmaniasis. Using any protocol,
subcutaneous injections have been totally without protective effects as have
been killed promastigotes injected by any route to mice. Subcutaneous injections
appear to be ineffective rather than counterproductive in that mice injected by
both the intravenous and subcutaneous routes with nonpathogenic living cloned
promastigotes resemble mice injected by the intravenous route in their disease
status following challenge.
====================================================
18.) Leishmaniasis.
====================================================
Infect Dis Clin North Am 1993 Sep;7(3):527-46 Related Articles, Links
Evans TG.
Department of Medicine, University of Utah, Salt Lake City.
Leishmanial infections include three major clinical syndromes: visceral,
cutaneous, and mucosal leishmaniasis. Visceral leishmaniasis, usually due to
Leishmania donovani, has received increasing attention in the United States
because of the growing number of cases seen in AIDS patients and the occurrence
of viscerotropic L. tropica disease among Persian Gulf war participants.
Cutaneous leishmaniasis is a relatively benign disease caused by L. Mexicana and
L. (Viannia) species in the New World, and L. major, L. tropica, and L.
aethiopica in the Old World. Many of these cutaneous lesions are self-healing,
and treatment recommendations vary and continue to undergo evolution and study.
Mucosal disease, caused by Leishmania (V.) braziliensis, is difficult to
diagnose as well as to treat. A practical approach to the clinical presentation,
diagnostic measures, and some treatment options of these syndromes is presented
in relation to specific case studies.
====================================================
19.) Leishmania (Leishmania) amazonensis-induced cutaneous leishmaniasis in the
primate Cebus apella: a model for vaccine trials.
====================================================
Int J Parasitol 2002 Dec 19;32(14):1755-64
Garcez LM, Goto H, Ramos PK, Brigido Mdo C, Gomes PA, Souza RA, De Luca PM,
Mendonca SC, Muniz JA, Shaw JJ.
Secao de Parasitologia, Programa de Imunologia, Instituto Evandro Chagas,
Fundacao Nacional de Saude, Ministerio da Saude-BR 316, Km 7 S/N, CEP
67.030-070, Ananindeua, PA, Brazil. [email protected]
A primate model of leishmaniasis was developed with the objective of future
vaccine testing. Lesion development and immunological parameters were studied
upon primary and secondary infections. Seven Cebus apella were injected
subcutaneously with 2 x 10(6) Leishmania (Leishmania) amazonensis promastigotes.
Erythematous nodules appeared 19-29 days p.i., which disappeared 100 days p.i.
Four months later, six of the monkeys were challenged with the same inoculum;
three of them developed erythematous nodules after 7 days p.i., with ulcer
formation in two of these subjects. The lesions were short-lived and all were
cured 40 days post challenge. Anti-Leishmania IgG antibodies were detected and
they increased after the challenge infection. Leishmania antigen-induced
lymphoproliferation was found 1 month post-primary infection, which coincided
with IFN-gamma production and lesion development. It decreased to control levels
afterwards, but at the time of the challenge dose, it was significantly above
the initial level. After the challenge infection, it first increased then
decreased sharply at 40 days post-challenge, coinciding with the healing of the
lesion. It increased again to a higher level at 60 days post-challenge.
Leishmania (Leishmania) amazonensis-infection in C. apella did not induce
complete protection against a secondary infection with a homologous parasite
although specific antibody production and lymphoproliferation with IFN-gamma
production were observed. This fact indicates that vaccine has to be better than
infection in the induction of protective immunity, and raises a question on in
vitro parameters that should be considered as a counterpart of expected
protection induced by vaccine candidate. In addition, we conclude that this is a
useful primate model for the evaluation of candidate vaccines.
====================================================
20.) [Experimental skin leishmaniasis: II--course of the infection in the Cebus
apella primate (Cebidae) caused by Leishmania (V.) braziliensis and L. (L.)
amazonensis]
====================================================
Rev Soc Bras Med Trop 1990 Jan-Mar;23(1):5-12
[Article in Portuguese]
Silveira FT, Lainson R, Shaw JJ, Garcez LM, Souza AA, Braga RR, Ishikawa EA.
Instituto Evandro Chagas Fundacao SESP, Brasil.
As a means of assessing the usefulness of the monkey Cebus apella as an
experimental model for the study of cutaneous leishmaniasis, 5 of these animals
were inoculated intradermally at 8 sites along the tail with 3 X 10(6)
promastigotes of L. (V.) braziliensis, while a further 5 monkeys received
similar inoculations with 3 X 10(6) promastigotes of L. (L.) amazonensis.
Following the inoculations, weekly examinations and monthly biopsies showed
evolution of resulting skin lesions to be as follows: a) L. (V.) braziliensis:
lesions were first visible 15-20 days post-inoculation (p.i), and at 30 days
they were clearly of an erythematous-papular nature, which assumed a nodular
form at 60 days; after 3 months a spontaneous ulceration of these lesions was
noted and, at 4 months, the initiation of healing. In one animal total healing
was apparent 5 months p.i; in two others at 6 months, in another monkey after 7
months, and in the last animal at 10 months p.i. Amastigotes were demonstrated
in smears from the lesions of all monkeys up to 90 days p.i; up to 120 days in
two animals, and at 180 days p.i. in the monkey which showed resolution of the
lesions after 10 months. b) L. (L.) amazonensis lesions were first apparent
after 20 days p.i; at 30 days they were of an erythematous-papular nature,
developing into nodules at 60 days. From the third month of infection onwards,
however, the lesions diminished rapidly and, at 90 days p.i. amastigotes were no
longer detectable in the skin.(ABSTRACT TRUNCATED AT 250 WORDS)
====================================================
21.) Leishmania (Leishmania) major-infected rhesus macaques (Macaca mulatta)
develop varying levels of resistance against homologous re-infections.
====================================================
Mem Inst Oswaldo Cruz 2001 Aug;96(6):795-804
Amaral VF, Teva A, Porrozzi R, Silva AJ, Pereira MS, Oliveira-Neto MP, Grimaldi
G Jr.
Departamento de Imunologia, Instituto Oswaldo Cruz-Fiocruz, 21045-900 Rio de
Janeiro, RJ, Brasil.
Seven rhesus macaques were infected intradermally with 10(7) promastigotes of
Leishmania (Leishmania) major. All monkeys developed a localized, ulcerative,
self-healing nodular skin lesion at the site of inoculation of the parasite.
Non-specific chronic inflammation and/or tuberculoid-type granulomatous reaction
were the main histopathological manifestations of the disease. Serum
Leishmania-specific antibodies (IgG and IgG1) were detected by ELISA in all
infected animals; immunoblot analyses indicated that numerous antigens were
recognized. A very high degree of variability was observed in the
parasite-specific cell-mediated immune responses [as detected by measuring
delayed-type hypersensitivity (DTH) reaction, in vitro lymphocyte proliferation,
and gamma interferon (IFN-gamma) production] for individuals over time post
challenge. From all the recovered monkeys (which showed resolution of the
lesions after 11 weeks of infection), 57.2% (4/7) and 28.6% (2/7) animals
remained susceptible to secondary and tertiary infections, respectively, but the
disease severity was altered (i.e. lesion size was smaller and healed faster
than in the primary infection). The remaining monkeys exhibited complete
resistance (i.e. no lesion) to each rechallenge. Despite the inability to
consistently detect correlates of cell-mediated immunity to Leishmania or
correlation between resistance to challenge and DTH, lymphocyte transformation
or IFN-gamma production, partial or complete acquired resistance was conferred
by experimental infection. This primate model should be useful for measuring
vaccine effectiveness against the human disease.
====================================================
22.) Protection of C57BL/10 mice by vaccination with association of purified
proteins from Leishmania (Leishmania) amazonensis.
====================================================
Rev Inst Med Trop Sao Paulo 1999 Jul-Aug;41(4):243-8
Mora AM, Mayrink W, Costa RT, Costa CA, Genaro O, Nascimento E.
Department of Parasitology, Institute of Biological Sciences, Federal University
of Minas Gerais, Brazil.
In the past few years, induction of protective immunity to cutaneous
leishmaniasis has been attempted by many researchers using a variety of
antigenic preparations, such as living promastigotes or promastigote extracts,
partially purified, or defined proteins. In this study, eleven proteins from
Leishmania (Leishmania) amazonensis (LLa) with estimated molecular mass ranging
from 97 to 13.5kDa were isolated by polyacrylamide gel electrophoresis and
electro-elution. The proteins were associated as vaccine in different
preparations with gp63 and BCG (Bacilli Calmette-Guerin). The antigenicity of
these vaccines was measured by their ability to induce the production of
IFN-gamma by lymphocyte from subjects vaccinated with Leishvacinregister mark or
target. The immunogenicity was evaluated in vaccinated mice. C57BL/10 mice were
vaccinated with three doses of each vaccine consisting of 30 microg of each
protein at 15 days interval. One hundred microg of live BCG was only used in the
first dose. Seven days after the last dose, they received a first challenge
infection with 10(5) infective promastigotes and four months later, a second
challenge was done. Two months after the second challenge, 42.86% of protection
was obtained in the group of mice vaccinated with association of proteins of
gp63+46+22kDa, gp63+13.5+25+42kDa, gp63+46+42kDa, gp63+66kDa, and gp63+97kDa;
57. 14% of protection was demonstrated with gp63+46+97+13.5kDa, gp63+46+97kDa,
gp63+46+33kDa, and 71.43% protection for gp63 plus all proteins. The vaccine of
gp63+46+40kDa that did not protect the mice, despite the good specific
stimulation of lymphocytes (LSI = 7. 60) and 10.77UI/ml of IFN-gamma production.
When crude extract of L. (L.) amazonensis was used with BCG a 57.14% of
protection was found after the first challenge and 28.57% after the second, the
same result was observed for gp63. The data obtained with the vaccines can
suggest that the future vaccine probably have to contain, except the 40kDa, a
cocktail of proteins that would protect mice against cutaneous leishmaniasis.
====================================================
23.) Experimental cutaneous leishmaniasis. IV. The humoral response of Cebus
apella (Primates: Cebidae) to infections of Leishmania (Leishmania) amazonensis,
L. (Viannia) lainsoni and L. (V.) braziliensis using the direct agglutination
test.
====================================================
Acta Trop 1997 Oct 14;68(1):65-76
Garcez LM, Silveira FT, el Harith A, Lainson R, Shaw JJ.
Leishmaniasis Program, Evandro Chagas Institute, Belem, Para, Brazil.
The direct agglutination test (DAT) was used to evaluate the serological
response of 150 serum samples taken from 15 captive-bred capuchin monkeys Cebus
apella. These animals had been experimentally infected with either L.
(Leishmania) amazonensis, L. (Viannia) lainsoni or L. (V.) braziliensis. Monkeys
infected with L. (L.) amazonensis or L. (V.) lainsoni were challenged with the
homologous parasite one month after their spontaneous cure. DAT antigens were
prepared from L. (L.) donovani, L. (L.) amazonensis and L. (V.) braziliensis.
Antigens were difficult to standardise and it was impossible to produce an L.
(V.) lainsoni antigen as parasites remained aggregated even after
trypsinization. The DAT detected significant humoral responses in all the
infected monkeys. Titres were higher when homologous antigens were used,
especially in secondary responses. This suggests that homologous antigen should
be used to detect antibodies in human cutaneous leishmaniasis.
====================================================
24.) Vaccination of C57BL/10 mice against cutaneous Leishmaniasis using killed
promastigotes of different strains and species of Leishmania.
====================================================
Rev Soc Bras Med Trop 2002 Mar-Apr;35(2):125-32
Mayrink W, Santos GC, Toledo Vde P, Guimaraes TM, Machado-Coelho GL, Genaro O,
da Costa CA.
Departamento de Parasitologia, Instituto de Ciencias Biologicas, Universidade
Federal de Minas Gerais, Belo Horizonte, MG.
Antigenic extracts from five Leishmania stocks were used to vaccinate C57BL/10
mice. The Leishvacin(R) and PH8 monovalent vaccine yielded the highest IFN-gamma
levels in the supernatants of spleen cell culture from vaccinated animals. Each
single strain immunized group showed evidence of protective immunity six months
after the challenge with promastigotes of Leishmania (Leishmania) amazonensis.
No differences were detected between the vaccinated groups. It can be concluded
that vaccines composed of single Leishmania stocks can provide protection to
C57BL/10 mice against L. (L.) amazonensis infection.
====================================================
25.) [Experimental cutaneous leishmaniasis: I--on the susceptibility of the
primate Cebus apella (Cebidae) to the infection caused by Leishmania (Viannia)
lainsoni Silveira, Shaw and Ishikawa, 1987]
====================================================
Rev Soc Bras Med Trop 1989 Jul-Sep;22(3):125-30
[Article in Portuguese]
Silveira FT, Lainson R, Shaw JJ, Garcez LM, Souza AA, Braga RR, Ishikawa EA.
The susceptibility of the monkey Cebus apella (Cebidae) to experimental
infection by Leishmania (Viannia) lainsoni has been investigated. For this
purpose, five young monkeys, 2 males and 3 females, were intradermally,
inoculated, in eight different places along the dorsal surface of the tail with
3 x 10(6) promastigotes of the parasite (MHOM/BR/81/M6426, Benevides, Para),
from stationary phase culture in Difco B45 medium. After inoculations, infection
in the monkeys was indicated by the presence of amastigotes in the skin lesions
produced in these animals at the points of inoculation, confirming the
susceptibility of the monkey Cebus apella to experimental infection by
Leishmania lainsoni, with an infection period of four months. This represents a
suitable period for testing antileishmanial drugs or studying the pathogenesis
of the disease caused by this parasite.
====================================================
26.) [Experimental cutaneous leishmaniasis. III. Histopathological aspects of
the developmental behavior of the cutaneous lesion induced in Cebus apella
(Primates: Cebidae) by Leishmania (Viannia) lainsoni, L. (V.) braziliensis and
L. (Leishmania) amazonensis]
====================================================
Rev Inst Med Trop Sao Paulo 1990 Nov-Dec;32(6):387-94
[Article in Portuguese]
Silveira FT, Moraes MA, Lainson R, Shaw JJ.
Secao de Parasitologia, Instituto Evandro Chagas (Fundacao SESP), Belem, Para,
Brasil.
We have studied the histopathological aspects related to the evolution of
cutaneous lesions experimentally produced in the monkey Cebus apella (Primates:
Cebidae) by Leishmania (V.) lainsoni, L. (V.) braziliensis and L. (L.)
amazonensis. Microscopical examination of a series of biopsies obtained from
these animals showed the kinetics of the cutaneous lesions regarding three
species of Leishmania inoculated, as follows: 1) an initial non-specific chronic
inflammatory infiltrate; 2) macrophagic nodules; 3) necrosis of parasitized
phagocytic cells; 4) epitheliode granuloma; 5) absorption of the necrotic area
(sometimes forming "foreign-body granuloma"); 6) a non-specific residual
inflammatory infiltration; and 7) cicatrization. These pathological processes
are, of course, responsible for both development and resolution of the
leishmaniotic lesion. We also discuss some immunopathological mechanisms
probably related with the sequential events, and that could be also responsible
for the different clinical aspects found in man.
====================================================
27.) Immune responses induced by a Leishmania (Leishmania) amazonensis
recombinant antigen in mice and lymphocytes from vaccinated subjects.
====================================================
Rev Inst Med Trop Sao Paulo 1997 Mar-Apr;39(2):71-8
Fernandes AP, Herrera EC, Mayrink W, Gazzinelli RT, Liu WY, de Costa CA, Tavares
CA, Melo MN, Michalick MS, Gentz R, Nascimento E.
Departamento de Parasitologia, Universidade Federal de Minas Gerais, Belo
Horizonte, Brazil.
In the search for Leishmania recombinant antigens that can be used as a vaccine
against American Cutaneous Leishmaniasis, we identified a Leishmania
(Leishmania) amazonensis recombinant protein of 33 kD (Larp33) which is
recognized by antibodies and peripheral blood leukocytes (PBL) from subjects
vaccinated with Leishvacin, Larp33 was expressed in Escherichia coli after
cloning of a 2.2 kb Sau3 digested genomic fragment of L. (L.) amazonensis into
the pDS56-6 His vector. Immunoblotting analysis indicated that Larp33
corresponds to an approximately 40-kD native protein expressed in promastigotes
of L. (L.) amazonensis and L. (Viannia) braziliensis. Northern blots of total
RNA also demonstrated that the gene coding for this protein is expressed in
promastigotes of the major lineages of Leishmania causing American Cutaneous
Leishmaniasis. Larp33 induced partial protection in susceptible mouse strains
(BALB/c and C57BL/10) against L. (L.) amazonensis after vaccination using
Bacille Calmette-Guerin (BCG) as adjuvant. In vitro stimulation of splenocytes
from BALB/c protected mice with Larp33 elicited the secretion of IL-2 and
IFN-gamma, suggesting that a Th1 cell-mediated protective response is associated
with the resistance observed in these mice. As revealed by its immunogenic and
antigenic properties, this novel recombinant antigen is a suitable candidate to
compose a vaccine against cutaneous leishmaniasis.
====================================================
27.) Vervet monkeys vaccinated with killed Leishmania major parasites and
interleukin-12 develop a type 1 immune response but are not protected against
challenge infection.
====================================================
Infect Immun 2001 Jan;69(1):245-51
Gicheru MM, Olobo JO, Anjili CO, Orago AS, Modabber F, Scott P.
Institute of Primate Research, Nairobi, Kenya.
Leishmania major is a protozoan parasite that causes chronic cutaneous lesions
that often leave disfiguring scars. Infections in mice have demonstrated that
leishmanial vaccines that include interleukin-12 (IL-12) as an adjuvant are able
to induce protective immunity. In this study, we assessed the safety,
immunopotency, and adjuvant potential of two doses of IL-12 when used with a
killed L. major vaccine in vervet monkeys. The induction of cell-mediated
immunity following vaccination was determined by measuring delayed-type
hypersensitivity, in vitro lymphocyte proliferation, and gamma interferon
(IFN-gamma) production. Protection was assessed by challenging the animals with
L. major parasites and monitoring the course of infection. At low doses of IL-12
(10 microg), a small increase in the parameters of cell-mediated immunity was
observed, relative to those in animals that received antigen without IL-12.
However, none of these animals were protected against a challenge infection. At
higher doses of IL-12 (30 microg), a substantial increase in Leishmania-specific
immune responses was observed, and monkeys immunized with antigen and IL-12
exhibited an IFN-gamma response that was as great as that in animals that had
resolved a primary infection and were immune. Nevertheless, despite the presence
of correlates of protection, the disease course was only slightly altered, and
protection was low compared to that in self-cured monkeys. These data suggest
that protection against leishmaniasis may require more than the activation of
Leishmania-specific IFN-gamma-producing T cells, which has important
implications for designing a vaccine against leishmaniasis.
====================================================
28.) Protective immunity using recombinant human IL-12 and alum as adjuvants in
a primate model of cutaneous leishmaniasis.
====================================================
J Immunol 1999 Oct 15;163(8):4481-8
Kenney RT, Sacks DL, Sypek JP, Vilela L, Gam AA, Evans-Davis K.
Laboratory of Parasitic Biology, Division of Veterinary Medicine, Center for
Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD
20852, USA. [email protected]
Protection from cutaneous leishmaniasis, a chronic ulcerating skin lesion
affecting millions, has been achieved historically using live virulent
preparations of the parasite. Killed or recombinant Ags that could be safer as
vaccines generally require an adjuvant for induction of a strong Th1 response in
murine models. Murine rIL-12 as an adjuvant with soluble Leishmania Ag has been
shown to protect susceptible mice. We used 48 rhesus macaques to assess the
safety, immunogenicity, and efficacy of a vaccine combining heat-killed
Leishmania amazonensis with human rIL-12 (rhIL-12) and alum (aluminum hydroxide
gel) as adjuvants. The single s.c. vaccination was found to be safe and
immunogenic, although a small transient s.c. nodule developed at the site.
Groups receiving rhIL-12 had an augmented in vitro Ag-specific IFN-gamma
response after vaccination, as well as increased production of IgG. No increase
in IL-4 or IL-10 was found in cell culture supernatants from either control or
experimental groups. Delayed hypersensitivity reactions were not predictive of
protection. Intradermal forehead challenge infection with 107 metacyclic L.
amazonensis promastigotes at 4 wk demonstrated protective immunity in all 12
monkeys receiving 2 microgram rhIL-12 with alum and Ag. Partial efficacy was
seen with lower doses of rhIL-12 and in groups lacking either adjuvant. Thus, a
single dose vaccine with killed Ag using rhIL-12 and alum as adjuvants was safe
and fully effective in this primate model of cutaneous leishmaniasis. This study
extends the murine data to primates, and provides a basis for further human
trials.
====================================================
29.) Leishmaniasis in Brazil: XII. Observations on cross-immunity in monkeys and
man infected with Leishmania mexicana mexicana, L. m. amazonensis, L.
braziliensis braziliensis, L. b. guyanensis and L. b. panamensis.
====================================================
J Trop Med Hyg 1977 Feb;80(2):29-35
Lainson R, Shaw JJ.
Cross-immunity trials in monkeys (Cebus apella apella) and observations on
experimental and natural infections in man confirm the separate identity of L.
mexicana mexicana, L. m. amazonensis, L. b. braziliensis, L. b. guyanensis and
L. b. panamensis. Neither L. m. mexicana nor L. m. amazonensis infections gave
protection against subsequent challenge with parasites of the L. braziliensis
complex; but recovery from infection with subspecies of L. braziliensis in most
cases gave firm resistance to infection with the mexicana parasites. The failure
of certain New World leishmanias to immunize against each other has an important
bearing on taxonomy, future attempts to prepare vaccines against Leishmania,
epidemiology and diagnosis.
====================================================
30.) Leishmania pifanoi amastigote antigens protect mice against cutaneous
leishmaniasis.
====================================================
Infect Immun 1995 Sep;63(9):3559-66
Soong L, Duboise SM, Kima P, McMahon-Pratt D.
Department of Epidemiology and Public Health, Yale University School of
Medicine, New Haven, Connecticut 06520-8034, USA.
In the search for a leishmaniasis vaccine, extensive studies have been carried
out with promastigote (insect stage) molecules. Information in this regard on
amastigote (mammalian host stage) molecules is limited. To investigate host
immune responses to Leishmania amastigote antigens, we purified three
stage-specific antigens (A2, P4, and P8) from in vitro-cultivated amastigotes of
Leishmania pifanoi by using immunoaffinity chromatography. We found that with
Corynebacterium parvum as an adjuvant, three intraperitoneal injections of 5
micrograms of P4 or P8 antigen provided partial to complete protection of BALB/c
mice challenged with 10(5) to 10(7) L. pifanoi promastigotes. These immunized
mice developed significantly smaller or no lesions and exhibited a 39- to 1.6 x
10(5)-fold reduction of lesion parasite burden after 15 to 20 weeks of
infection. In addition, P8 immunization resulted in complete protection against
L. amazonensis infection of CBA/J mice and partial protection of BALB/c mice,
suggesting that this antigen provided cross-species protection of mice with
different H-2 haplotypes. At different stages during infection, vaccinated mice
exhibited profound proliferative responses to parasite antigens and increased
levels of gamma interferon production, suggesting that a Th1 cell-mediated
immune response is associated with the resistance in these mice. Taken together,
the data in this report indicate the vaccine potential of amastigote-derived
antigens.
====================================================
31.) Specific immunization of mice against Leishmania mexicana amazonensis using
solubilized promastigotes.
====================================================
Clin Exp Immunol 1987 Jan;67(1):11-9
Barral-Netto M, Reed SG, Sadigursky M, Sonnenfeld G.
Successful immunization of highly susceptible BALB/c mice against progressive
infection by Leishmania mexicana amazonensis, using whole solubilized
promastigotes was achieved. The best immunization schedule consisted of three
weekly injections of 5 X 10(7) parasite equivalents. Intravenous was superior to
intraperitoneal or subcutaneous immunization. Protection persisted for up to 2
months after immunization, and beneficial effects could be observed in long-term
follow-up (24 weeks after infection). Immunized mice exhibited marked reduction
in primary lesion size, as well as reduction of the number of parasites in the
spleen, and developed less metastases. High titres of specific anti-L. m.
amazonensis IgG antibodies resulted from immunization, but titres did not
correlate with protection. Groups with widely differing pre-infection antibody
titres were equally protected, and similar antibody titres resulted in different
levels of protection. Immunization alone did not induce significant serum
interferon-gamma levels and specific delayed-type hypersensitivity (DTH)
reactions, but resulted in the persistence of positive (DTH) reactions after
infection, at a time when infected control animals had suppressed responses.
Resistance to leishmaniasis appears to depend on cell mediated immune
mechanisms, and the possibility of immunization with a solubilized antigen
without adjuvant is intriguing and opens new perspectives in this area.
====================================================
32.) Membrane glycoprotein M-2 protects against Leishmania amazonensis
infection.
===================================================
Infect Immun 1988 Dec;56(12):3272-9
Champsi J, McMahon-Pratt D.
Department of Epidemiology, Yale University School of Medicine, New Haven,
Connecticut 06510.
Previous passive antibody transfer experiments have indicated that immunity to a
46-kilodalton membrane glycoprotein (M-2) of Leishmania amazonensis may protect
against infection with this parasite. In the studies described in this paper, we
investigated the ability of the purified M-2 molecule to elicit a protective
immune response in conjunction with Freund incomplete and complete adjuvants,
saponin, and Corynebacterium parvum. Both relatively susceptible (BALB/c and
CBA) and resistant (C57BL/6) strains of mice were examined. C. parvum appeared
to be the most effective adjuvant in the three mouse strains tested. The level
of protection varied with the mouse strain, although all animals received
identical preparations of antigen and adjuvant. Immunization of CBA mice with
the M-2 glycoprotein and C. parvum resulted in complete protection against a
challenge infection of 10(4) and 10(6) late log-phase promastigotes of L.
amazonensis. In the BALB/c strain, complete protection was observed in some of
the immunized animals (28 to 50%); in the rest of the mice the onset of
infection was significantly delayed. Protective immunity for C57BL/6 mice was
observed only at the low infecting dose (10(4) L. amazonensis organisms). The
level of protection observed is reflected by increased antibody response
(immunoglobulins G1 and G2) developed to the M-2 molecule. The relationship of
pure T-cell (nonantibody) immunity to this protection remains to be elucidated.
====================================================
33.) The role of BCG in human immune responses induced by multiple injections of
autoclaved Leishmania major as a candidate vaccine against leishmaniasis.
====================================================
Vaccine 2002 Dec 13;21(3-4):174-80 Related Articles, Links
Alimohammadian MH, Khamesipour A, Darabi H, Firooz A, Malekzadeh S, Bahonar A,
Dowlati Y, Modabber F.
Department of Immunology, Pasteur Institute of Iran, Tehran, Iran
To determine if BCG was required in booster injections for autoclaved Leishmania
major (ALM) vaccine, 75 volunteers with no response to leishmanin were injected
double-blind and randomly with either ALM+BCG or BCG alone for the first
injection and boosted either with ALM+BCG, ALM or BCG alone for the second and
third. Addition of BCG to the boosters significantly increased the frequency and
the magnitude of leishmanin skin tests (LSTs); however, there was no difference
in proliferative and IFN-gamma responses (a month and a year later). Three
injections of BCG produced no observable adverse reaction; hence BCG could be
used in booster injections to increase the protective potential of this
candidate vaccine.
====================================================
34.) Randomised vaccine trial of single dose of killed Leishmania major plus BCG
against anthroponotic cutaneous leishmaniasis in Bam, Iran.
====================================================
Lancet 1998 May 23;351(9115):1540-3
Sharifi I, FeKri AR, Aflatonian MR, Khamesipour A, Nadim A, Mousavi MR, Momeni
AZ, Dowlati Y, Godal T, Zicker F, Smith PG, Modabber F.
Kerman University of Medical Sciences, Medical School, Iran.
BACKGROUND: A vaccine consisting of a single dose of whole-cell autoclave-killed
Leishmania major (ALM) mixed with BCG was assessed in comparison with BCG alone
against anthroponotic (human to human transmission) cutaneous leishmaniasis in a
randomised double-blind trial in Bam, Iran. METHODS: 3637 schoolchildren, aged
6-15 years, with no history of cutaneous leishmaniasis and no response to a
leishmanin skin test, were randomly assigned to receive 1 mg ALM mixed with BCG
(n = 1839), or BCG alone (n = 1798). Safety of the vaccine and the incidence of
confirmed cases of cutaneous leishmaniasis were followed up for 2 years.
FINDINGS: Side-effects were those usually associated with BCG vaccination, but
tended to persist longer in the ALM + BCG group. After exclusion of four cases
occurring within 80 days of vaccination (one in the ALM + BCG group and three in
the BCG group), the 2-year incidence of cutaneous leishmaniasis did not differ
significantly between vaccine and BCG groups: 2.8% vs 3.3%, respectively (total
cases 112). A sex-stratified analysis showed that in boys the vaccine conferred
a protective efficacy of 18% and 78% for the first and second years,
respectively--a crude 2-year overall protection of 55% (95% CI 19-75%, p <
0.01). In the first 9 months after vaccination, there was a non-significant
excess of cases in the ALM + BCG group (25 vs 16), whereas the incidence of
cutaneous leishmaniasis thereafter was significantly reduced in the ALM + BCG
group (27 vs 44, p < 0.05). INTERPRETATION: A single dose of ALM + BCG was safe
and more immunogenic than BCG alone, as measured by leishmanin skin test. The
exact reason for the apparent protective effect of the vaccine in boys is
unknown, and may be a chance finding. However, since boys are more exposed to
the infection, which is indicated by higher disease prevalence in boys in this
study population, the preferential protective effect in boys may have resulted
from a greater booster effect produced by repeated exposure to infected
sandflies. Booster injections or alternative adjuvants should be tried to
improve the potential efficacy of this vaccine.
====================================================
35.) A randomised, double-blind, controlled trial of a killed L. major vaccine
plus BCG against zoonotic cutaneous leishmaniasis in Iran.
====================================================
Vaccine 1999 Feb 5;17(5):466-72
Momeni AZ, Jalayer T, Emamjomeh M, Khamesipour A, Zicker F, Ghassemi RL, Dowlati
Y, Sharifi I, Aminjavaheri M, Shafiei A, Alimohammadian MH, Hashemi-Fesharki R,
Nasseri K, Godal T, Smith PG, Modabber F.
Isfahan University of Medical Sciences, Iran.
Safety and efficacy of killed (autoclaved) L. major promastigotes, ALM, mixed
with BCG against zoonotic cutaneous leishmaniasis was tested in healthy
volunteers (n = 2453) in a randomized double blind trial vs. BCG as control.
Side-effects were similar in both groups but tended to be slightly more frequent
and prolonged in the ALM + BCG group. Leishmanin skin test conversion
(induration > or =5 mm) was significantly greater in the ALM + BCG than in the
BCG group (36.2% vs. 7.9% on day-80 and 33% vs. 19%, after 1 year,
respectively). Cumulative incidence rates for 2 years, were similar in both
groups (18.0% vs. 18.5%). However, LST responders on day 80 (> or =5 mm) had a
significantly lower incidence (35%) of CL during the first year than
non-responders. A single dose of ALM + BCG is not sufficiently immunogenic to
provide a measurable response when compared to BCG alone. A single dose of this
vaccine has been shown to be safe with no evidence of an exacerbating response
following natural infection; hence, multiple doses or other adjuvants should be
considered to increase its immunogenicity.
====================================================
36.) Immunogenicity and safety of autoclaved Leishmania major plus BCG vaccine
in healthy Sudanese volunteers.
====================================================
Vaccine 2001 Feb 28;19(15-16):2100-6
Satti IN, Osman HY, Daifalla NS, Younis SA, Khalil EA, Zijlstra EE, El Hassan
AM, Ghalib HW.
Institute of Endemic Diseases, University of Khartoum, P. O. Box 102, Khartoum,
Sudan. [email protected]
In a longitudinal study in the epidemiology of Leishmania donovani infection in
an endemic focus in eastern Sudan, we observed that previous exposure or
infection with Leishmania major appeared to protect against visceral
leishmaniasis caused by L. donovani. We therefore conducted a study to test the
safety and immunogenicity of a vaccine consisting of autoclaved L. major (ALM)
plus BCG in inducing protection in vaccinated individuals. Leishmanin-negative
healthy Sudanese volunteers were enrolled in the study and were divided into
three groups: group (A) received ALM+BCG, group (B) received BCG alone, and
group (C) received the vaccine diluent. The subjects were examined for their
clinical and immunological responses before intervention, following intervention
and 6-8 weeks after vaccination. Vaccinated subjects (group A) developed
localized reactions at the sites of vaccine inoculation that ulcerated and
healed within 4-6 weeks; 61.6% of them converted to leishmanin reactive
following vaccination. Only one subject in group (C) became leishmanin-positive.
A total 76.9% of the vaccinated volunteers in group (A) produced significant
levels of interferon-gamma in response to L. major antigen. The vaccine produced
significant cellular immune responses that may protect against natural
challenge. None of the groups had systemic reactions and all the reactions
observed in the vaccinated group were comparable with the BCG-vaccinated group.
====================================================
37.) Immune responses in vaccinated dogs with autoclaved Leishmania major
promastigotes.
====================================================
Vet Res 1999 Sep-Oct;30(5):441-9
Lasri S, Sahibi H, Sadak A, Jaffe CL, Rhalem A.
Departement de parasitologie et maladies parasitaires, Institut agronomique et
veterinaire Hassan-II, Rabat, Morocco.
A comparative study was undertaken on the immunogen power of autoclaved
Leishmania major promastigotes (ALM) vaccines given simultaneously with either
BCG or saponin against canine leishmaniasis. The humoral immune response was
assessed by ELISA and western blotting. The cellular immune response was
evaluated by the lymphocyte transformation test. Dogs vaccinated simultaneously
with ALM and saponin showed high antibody titres to crude L. infantum antigens
after the first vaccine booster and reacted with several antigens, with
molecular weights from 26 to 108 kDa by western blotting. However, the
lymphocyte proliferation of these dogs to the crude L. infantum antigen was not
significantly different from the control group. In contrast, in dogs vaccinated
simultaneously with ALM and BCG, the antibody titres to crude antigen were low.
Their sera reacted with the same proteins recognised by sera from dogs
vaccinated simultaneously with ALM and saponin by western blotting. However, the
85-kDa protein was only identified by sera taken from dogs vaccinated
simultaneously with ALM and BCG. These latter exhibited specific lymphocyte
proliferation to the L. infantum antigen. This cell proliferation was observed
for approximately 9 months after the first dose of the vaccine. This study
indicates that a combination of ALM as the vaccine and BCG as the adjuvant, in
the dog model, was successful in inducing a cell immune response, which is
implicated in protection of dogs against a Leishmania infection.
====================================================
38.) Study of the safety, immunogenicity and efficacy of attenuated and killed
Leishmania (Leishmania) major vaccines in a rhesus monkey (Macaca mulatta) model
of the human disease.
====================================================
Mem Inst Oswaldo Cruz 2002 Oct;97(7):1041-8
Amaral VF, Teva A, Oliveira-Neto MP, Silva AJ, Pereira MS, Cupolillo E, Porrozzi
R, Coutinho SG, Pirmez C, Beverley SM, Grimaldi G Jr.
Departamento de Imunologia, Instituto Oswaldo Cruz-Fiocruz, Rio de Janeiro,
Brasil.
We have compared the efficacy of two Leishmania (Leishmania) major vaccines, one
genetically attenuated (DHFR-TS deficient organisms), the other inactivated
[autoclaved promastigotes (ALM) with bacillus Calmete-Guerin (BCG)], in
protecting rhesus macaques (Macaca mulatta) against infection with virulent L.
(L.) major. Positive antigen-specific recall proliferative response was observed
in vaccinees (79% in attenuated parasite-vaccinated monkeys, versus 75% in
ALM-plus-BCG-vaccinated animals), although none of these animals exhibited
either augmented in vitro gamma interferon (IFN-gamma) production or positive
delayed-type hypersensitivity (DTH) response to the leishmanin skin test prior
to the challenge. Following challenge, there were significant differences in
blastogenic responses (p < 0.05) between attenuated-vaccinated monkeys and naive
controls. In both vaccinated groups very low levels of antibody were found
before challenge, which increased after infective challenge. Protective immunity
did not follow vaccination, in that monkeys exhibited skin lesion at the site of
challenge in all the groups. The most striking result was the lack of
pathogenicity of the attenuated parasite, which persisted in infected animals
for up to three months, but were incapable of causing disease under the
conditions employed. We concluded that both vaccine protocols used in this study
are safe in primates, but require further improvement for vaccine application.
====================================================
39.) Safety and immunogenicity of a killed Leishmania (L.) amazonensis vaccine
against cutaneous leishmaniasis in Colombia: a randomized controlled trial.
====================================================
Trans R Soc Trop Med Hyg 2000 Nov-Dec;94(6):698-703
Velez ID, del Pilar Agudelo S, Arbelaez MP, Gilchrist K, Robledo SM, Puerta JA,
Zicker F, Berman J, Modabber F.
Programme for the Study and Control of Tropical Diseases (PECET), Universidad de
Antioquia, Apartado Aereo 1226, Medellin, Colombia. [email protected]
The safety and immunogenicity of an intramuscular (i.m.) and intradermal (ID)
formulation of autoclaved Leishmania (Leishmania) amazonensis vaccine was
evaluated in 296 volunteers in a randomized, placebo-controlled, double-blind
trial in Colombia. There were 4 vaccination groups: i.m. vaccine, i.m. placebo,
ID vaccine, and ID placebo. The ID formulations were mixed with BCG as adjuvant
at the time of injection. For each group, 3 vaccinations were given with a
20-day interval between injections, and adverse events were monitored at 20 min,
and at 2, 7 and 21 days after each injection. BCG-induced adverse reactions
resulted in cancellation of the third vaccine administration in the ID groups.
Antibody titres did not differ significantly between the groups. Montenegro
skin-test conversion was achieved by 86.4% and 90% of the i.m. vaccine group and
by 25% and 5% of the i.m. placebo group 80 days and 1 year after vaccination,
respectively. A significant increase in mean Leishmania-antigen lymphocyte
proliferation indexes was observed after i.m. vaccine immunization, but not
after i.m. placebo immunization, 80 days and 1 year after vaccination.
Significant levels of IFN gamma but not IL-10 were observed 1 year after
vaccination in the i.m. vaccine group compared to the i.m. placebo group. The
good safety profile and evidence of Th1 immune reactions due to i.m. vaccination
in this phase-I/II study suggest that a population-based phase-III efficacy
trial of the i.m. vaccine should be initiated.
====================================================
40.) Immune response in healthy volunteers vaccinated with killed leishmanial
promastigotes plus BCG. I: Skin-test reactivity, T-cell proliferation and
interferon-gamma production.
====================================================
Vaccine 1994 Aug;12(11):1041-51
Castes M, Blackwell J, Trujillo D, Formica S, Cabrera M, Zorrilla G, Rodas A,
Castellanos PL, Convit J.
Instituto de Biomedicina, Facultad de Medicina, Universidad Central de
Venezuela, Caracas.
This study reports the results of a vaccine trial established to study the
cellular immune responses in vivo (skin-test reactivity) and in vitro (T-cell
proliferation and interferon-gamma production) to both leishmanial and
mycobacterial antigens following vaccination of healthy volunteers from a
leishmaniasis-endemic area with killed leishmanial promastigotes, with or
without BCG (Bacille Calmette-Guerin). Skin tests were performed using purified
protein derivative of tuberculin (PPD) and leishmanial antigen in 692
volunteers, and 208 doubly negative subjects (< or = 7 mm induration) were
selected to participate in the trial. The study subjects were divided into four
vaccine groups: (A) killed promastigotes plus BCG, (B) BCG alone, (C) killed
promastigotes alone, and (D) placebo. Three vaccine doses were administered at
6-10-week intervals. The skin-test responses to PPD and leishmanial antigen were
reassessed at 4-6- and 12-18-month follow-ups. The results of this trial
demonstrated that the combined vaccine, i.e. killed promastigotes of Leishmania
plus BCG, results in the stimulation of an immune response to both leishmania
and mycobacterial antigens in a high percentage of vaccines (> 85%), manifested
either by skin-test conversion, lymphocyte proliferation and/or interferon-gamma
production. This was evident after the first dose of vaccine for lymphocyte
proliferation and interferon-gamma production and was maintained for a year
after the three doses of vaccine. Group B (which received BCG alone), responded
as well as group A to PPD but not as well to leishmanial antigen. The reverse
was true for group C which received promastigotes alone. Group A attained a 38%
leishmanin skin-test conversion at the 4-6-month follow-up, which was associated
with double PPD/leishmanial antigen responder status. In contrast, a 35%
skin-test conversion was found at the 12-18-month follow-up in group C
(promastigotes alone), but this was not associated with responses to PPD. A
significant percentage of conversion was observed in the placebo group at the
12-18-month follow-up, both to PPD (58%) and leishmanial (21%) antigens, which
suggests either environmental exposure to mycobacterial or leishmanial antigens
during the vaccine trial or, more probably, a response to the repeated
leishmanial skin tests. Further studies are required to determine whether the
presence of proliferative and/or interferon-gamma responses in the absence of a
skin-test response are sufficient indicators of potential vaccine success.
====================================================
41.) The effect of repeated leishmanin skin testing on the immune responses to
Leishmania antigen in healthy volunteers.
====================================================
Trans R Soc Trop Med Hyg 2002 Sep-Oct;96(5):565-7
Satti I, el Hassan A, Khalil el TA, Akuffo H.
Microbiology and Tumour Biology Centre, Karolinska Institute, Box 280, S-171 77
Stockholm, Sweden.
The leishmanin skin test (LST) is used in immunogenicity studies. The effect of
multiple LSTs on immune responses was assessed. None of the volunteers converted
to LST positive. IFN-gamma and IL-10 levels remained unchanged. Repetition of
LST does not modulate the in vivo or in vitro immune responses to Leishmania
antigen.
====================================================
42.) Evaluation of the stability and immunogenicity of autoclaved and
nonautoclaved preparations of a vaccine against American tegumentary
leishmaniasis.
====================================================
Vaccine 1999 Mar 5;17(9-10):1179-85
De Luca PM, Mayrink W, Alves CR, Coutinho SG, Oliveira MP, Bertho AL, Toledo VP,
Costa CA, Genaro O, Mendonca SC.
Departamento de Protozoologia, Instituto Oswaldo Cruz, FIOCRUZ, Rio de
Janeiro-RJ, Brasil.
This study was designed to evaluate the immunogenicity of autoclaved and
nonautoclaved preparations of a vaccine composed of whole antigens from killed
promastigotes of Leishmania amazonensis. Leishmanin skin-test (LST)-negative
volunteers were immunized with either autoclaved or nonautoclaved vaccine
preparations (32 and 36 subjects, respectively) that had been maintained at 4
degrees C for one year before the onset of this trial. Immunological tests were
performed two days before and 40 days after vaccination. The LST conversion
rates induced by the autoclaved and nonautoclaved vaccines were significantly
different: 59% and 83%, respectively. Leishmania antigen-stimulated
proliferative responses of peripheral blood mononuclear cells (PBMC) were
significantly higher after vaccination than before vaccination in both groups.
The CD8+ subset was predominant over the CD4+ subset among the
leishmania-reactive cells after vaccination in both groups. The production of
IFN-gamma by the leishmania antigen-stimulated PBMC was significantly higher
after vaccination than before vaccination in the group receiving the
nonautoclaved vaccine but not in the autoclaved vaccine group. IL-2 was found
both before and after vaccination with no differences between its levels in
these time points in either group. IL-4 was not detected for either group during
the study period.
====================================================
43.) A randomized double-blind placebo-controlled trial to evaluate the
immunogenicity of a candidate vaccine against American tegumentary
leishmaniasis.
====================================================
Acta Trop 2001 Dec 21;80(3):251-60
De Luca PM, Mayrink W, Pinto JA, Coutinho SG, Santiago MA, Toledo VP, Costa CA,
Genaro O, Reis AB, Mendonca SC.
Departamento de Imunologia, Instituto Oswaldo Cruz, FIOCRUZ, Av. Brasil
4365-Manguinhos, CP 926, CEP 21045-900, Rio de Janeiro RJ, Brazil.
This study was aimed at evaluating the immunogenicity of a vaccine composed of
killed Leishmania amazonensis promastigotes using several different protocols in
a randomized, double-blind and controlled trial design in order to select one of
them for further efficacy trials. One hundred and fourteen leishmanin skin test
(LST)-negative healthy volunteers were allocated into eight groups that received
either two or three deep intramuscular injections of vaccine at doses of 180,
360 and 540 microg or similar injections of placebo. Cell-mediated immune
responses were evaluated before and after vaccination by means of LST as well as
proliferative responses and cytokine production in Leishmania antigen-stimulated
peripheral blood mononuclear cell cultures. The majority of the subjects who
actually received vaccine converted to positive LST (89.5%). On the other hand,
none of the subjects who received placebo converted to positive LST.
Proliferative responses and production of interferon-gamma and interleukin-2
were significantly higher after vaccination than before vaccination in all
groups, including those that received placebo. The dose of 360 microg provided
the highest LST conversion rate (100%), as well as the greatest increase in
interferon-gamma and interleukin-2 production after vaccination.
====================================================
44.) BCG expressing LCR1 of Leishmania chagasi induces protective immunity in
susceptible mice.
====================================================
Exp Parasitol 2000 Jan;94(1):33-41
Streit JA, Recker TJ, Donelson JE, Wilson ME.
Department of Internal Medicine, 300D EMRB, University of Iowa, Iowa City 52242,
USA.
Cellular immune responses are required for protective immunity against
Leishmania chagasi. Immunization strategies using live intracellular bacteria
(e.g., bacille-Calmette Guerin strain of Mycobacterium bovis) expressing
recombinant antigens can induce cellular immune responses to these antigens.
Previous studies demonstrated that the L. chagasi antigen LCR1 stimulates
IFN-gamma production from T cells of infected BALB/c mice, and immunization with
recombinant LCR1 partially protects against L. chagasi infection. To determine
whether live bacteria could enhance the immunization potential of LCR1, we
engineered BCG expressing LCR1 (BCG-LCR1). Subcutaneous immunization with
BCG-LCR1, but not with BCG containing plasmid only (BCG-pMV261), elicited better
protective immunity against L. chagasi infection than LCR1 protein alone.
BCG-LCR1 administered intraperitoneally did not protect. Splenocytes from mice
immunized s.c. with either BCG-LCR1 or BCG-pMV261 and then infected with L.
chagasi promastigotes had increased antigen-induced IFN-gamma and reduced IL-10
production compared to splenocytes of control mice. We propose that BCG-LCR1
promotes a Th1-type protective immune response, and it may be a useful component
of a Leishmania vaccine. Copyright 2000 Academic Press.
====================================================
45.) Immune response in healthy volunteers vaccinated with BCG plus killed
leishmanial promastigotes: antibody responses to mycobacterial and leishmanial
antigens.
====================================================
Vaccine 1994 Nov;12(15):1402-12 Related Articles, Links
Sharples CE, Shaw MA, Castes M, Convit J, Blackwell JM.
University of Cambridge Clinical School, Department of Medicine, Addenbrooke's
Hospital, UK.
Antibody (IgG) responses to mycobacterial (BCG; PPD; Mycobacterium leprae
soluble antigen, MLSA) and leishmanial (Leishmania mexicana LV4) antigens were
measured in 208 initially PPD and leishmanin skin-test negative volunteers
divided into four vaccine groups as follows: 68 received BCG plus killed
promastigotes (group A), 47 received BCG alone (group B), 47 received killed
promastigotes alone (group C), and 46 formed the diluent control (placebo, group
D). Three vaccine doses were administered at 8-12 week intervals. Vaccinees were
bled immediately prior to each vaccination, and again at 3- and 12-month
follow-up. Skin tests were performed prevaccination, and again at the 3- and
12-month follow-up. Anti-BCG, anti-PPD and anti-MLSA IgG levels increased
significantly in groups A and B receiving BCG. The presence of leishmanial
antigen (with BCG) in the inoculum suppressed the IgG response to Mycobacterium
tuberculosis/Mycobacterium bovis-related (PPD and BCG), but not M.
leprae-related (MLSA)-related, antigens. A small but significant increase
(relative to prevaccination level) in response to MLSA, but not to BCG or PPD
was observed in the non-BCG-vaccinated groups. The background level of response
to mycobacterial and leishmanial antigens was higher in the Venezuelan vaccinees
than in non-endemic (British) volunteers. Responses to leishmanial antigen were
not enhanced in the two vaccine groups receiving killed promastigotes
(with/without BCG) compared with the BCG alone and placebo groups. Instead, all
vaccine groups showed a pattern of response consistent with either (i) a
response to the skin-test antigen or, more likely, (ii) seasonal endemic
exposure to leishmanial antigen. Interestingly, this endemic response to
leishmanial antigen was enhanced in the vaccine groups receiving BCG, despite
the fact that group B received no leishmanial antigen in the vaccine inoculum.
When prevaccination IgG levels (mean + 3 standard deviations) were used to
determine a negative cut-off, a low percentage (< 38%) of vaccinees converted to
responder status for either anti-mycobacterial or anti-leishmanial responses,
and those who did would be classified as 'low-responder' status compared with
titres observed in severe forms of disease. Hence, although there was evidence
for a background endemic response to both leishmanial and mycobacterial
antigens, there was no evidence that vaccination per se led to a potentially
disease exacerbatory level of TH2-associated antibody response especially with
respect to the anti-leishmanial response.(ABSTRACT TRUNCATED AT 400 WORDS)
====================================================
46.) Immunotherapy with live BCG plus heat killed Leishmania induces a T helper
1-like response in American cutaneous leishmaniasis patients.
====================================================
Parasite Immunol 2000 Feb;22(2):73-9
Cabrera M, Blackwell JM, Castes M, Trujillo D, Convit J, Shaw MA.
Instituto de Biomedicina, Facultad de Medicina, Universidad Central de
Venezuela, Apdo 4043 (Carmelitas), Caracas 1010-A Venezuela.
Previous work has shown that American cutaneous leishmaniasis (ACL) patients
treated with viable BCG plus heat killed promastigotes of Leishmania amazonensis
show the same rate of cure as patients receiving conventional chemotherapy. The
treatment is safe and economical, but the immunological correlates of cure have
not been examined. In the present study, T cell responses have been analysed in
43 ACL patients, including patient groups sampled before and after therapy, and
in 10 endemic controls. Lymphocyte proliferation, interferon (IFN)-gamma and
interleukin (IL)-5 responses to crude antigen (L. amazonensis, MEL;
Mycobacterium tuberculosis PPD; M. bovis BCG) stimulation, and serum IL-5
levels, were analysed. In endemic volunteers, proliferative responses to BCG
were high and IFN-gamma responses low. In contrast, localized cutaneous (LCL)
and mucocutaneous (MCL) patients showed low proliferative and high IFN-gamma
responses to BCG. Treatment enhanced the IFN-gamma response and further
decreased the proliferative response to BCG, especially in MCL patients. LCL and
MCL patients showed an increase in proliferative and IFN-gamma responses to MEL
with treatment, but the response was not exaggerated in MCL patients, either
before or after treatment, compared to LCL patients. IL-5 production was low in
T cell assays, and > 62% of untreated patients had very low serum IL-5 levels.
There were no significant changes in serum IL-5 with treatment. Overall results
show enhanced antigen-specific IFN-gamma responses to the two components of the
immunotherapy, live M. bovis BCG and heat killed L. amazonensis, which is
consistent with a shift in balance of T cell response towards a T helper 1
response and clinical cure mediated by IFN-gamma.
====================================================
47.) Vaccination of mice with a combination of BCG and killed Leishmania
promastigotes reduces acute Trypanosoma cruzi infection by promoting an
IFN-gamma response.
====================================================
Vaccine 1999 Feb 26;17(7-8):957-64
Araujo Z, El Bouhdidi A, Heremans H, Van Marck E, Castes M, Carlier Y.
Catedra de Inmunologia, Escuela de Medicina Jose Maria Vargas, Facultad de
Medicina, Universidad Central de Venezuela, Caracas. [email protected]
The combination of BCG with killed Leishmania promastigotes, demonstrated to be
efficient in the cure of patients suffering American cutaneous leishmaniasis and
in the induction of a long-term immune response in healthy vaccinated
volunteers, was tested in BALB/c mice infected with Trypanosoma cruzi, in
comparison to BCG or Leishmania alone, and a vehicle (PBS) control.
BCG-Leishmania vaccination, applied intra-peritoneally 10 and 3 days before T.
cruzi trypomastigote inoculation, prolonged the survival, and reduced blood
parasitaemia of infected animals. Proliferation studies indicated that
splenocytes of mice vaccinated with BCG-Leishmania and harvested in the acute
phase of T. cruzi infection displayed stimulation indices higher than cells from
PBS-treated mice when stimulated with PHA mitogen, PPD, Leishmania or T. cruzi
antigens. Injections of a monoclonal antibody able to neutralise IFN-gamma into
BCG-Leishmania vaccinated mice increased parasitaemia to levels similar to those
of control animals (treated with PBS) and reversed the beneficial effect of
vaccination on the proliferative response to T. cruzi antigen. These results
show that vaccination of mice with BCG plus killed Leishmania promastigotes
delayed acute T. cruzi infection, stimulated a T-cell response to T. cruzi
antigen and promoted IFN-gamma production.
====================================================
48.) Immunization of BALB/c mice with mIFN-gamma-secreting Mycobacterium bovis
BCG provides early protection against Leishmania major infection.
====================================================
Int J Parasitol 1997 Mar;27(3):349-53
Kong D, Belosevic M, Kunimoto DY.
Department of Medical Microbiology and Immunology, University of Alberta,
Edmonton, Canada.
We developed and tested IFN-gamma-expressing Mycobacterium bovis, strain BCG,
for the ability to activate macrophages and protect mice against a heterologous
challenge with Leishmania major. One, 2 or 3 weeks after intraperitoneal
immunization, mice were challenged with 10(6) L. major amastigotes injected into
the right footpad. Recombinant BCG immunization for all 3 challenge time points
initially showed greater protection compared to the BCG control, as judged by
footpad thickness and number of parasites in the leishmanial lesion. However, at
week 4 after challenge, while the 1- and 2-week immunization groups continued to
show increased protection, the 3-week immunization group animals exhibited
progressive disease. These data suggest that the IFN-gamma-expressing BCG
initially activates macrophages more effectively than native BCG, but that late
exacerbation of disease can occur, highlighting the complexity of the immune
response against leishmaniasis.
====================================================
49.) Short report: evaluation of the potency and stability of a candidate
vaccine against American cutaneous leishmaniasis.
====================================================
Am J Trop Med Hyg 1999 Aug;61(2):294-5
Mayrink W, Pinto J, Da Costa C, Toledo V, Guimaraes T, Genaro O, Vilela L.
Departamento de Parasitologia, Instituto de Ciencias Biologicas/Universidade
Federal de Minas Gerais, Belo Horizonte, Brazil.
Availability of a safe, immunogenic, and affordable vaccine would represent the
best strategy for control of cutaneous leishmaniasis (CL). Stability in field
conditions is a essential property for any candidate vaccine. The stability and
immunogenicity of three different preparations (thimerosal-preserved,
autoclaved, and lyophilized) of a killed Leishmania amazonensis vaccine were
assessed using fresh products and after 12 months of storage at 4 degrees C.
Autoclaving was associated with a time-dependent decrease in the immunogenicity
of the vaccine, as measured by the leishmanin skin test and production of
interferon-gamma. These findings are of importance in the decision of which
preparation of candidate killed CL vaccines should move to phase III trials.
====================================================
50.) The immunology of susceptibility and resistance to Leishmania major in
mice.
====================================================
Nat Rev Immunol 2002 Nov;2(11):845-58
Sacks D, Noben-Trauth N.
Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious
Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA.
[email protected]
Established models of T-helper-2-cell dominance in BALB/c mice infected with
Leishmania major -- involving the early production of interleukin-4 by a small
subset of Leishmania-specific CD4+ T cells -- have been refined by accumulating
evidence that this response is not sufficient and, under some circumstances, not
required to promote susceptibility. In addition, more recent studies in L.
major-resistant mice have revealed complexities in the mechanisms responsible
for acquired immunity, which necessitate the redesign of vaccines against
Leishmania and other pathogens that require sustained cell-mediated immune
responses.
====================================================
51.) Optimization of DNA vaccination against cutaneous leishmaniasis.
====================================================
Vaccine 2002 Nov 1;20(31-32):3702-8 Related Articles, Links
Mendez S, Belkaid Y, Seder RA, Sacks D.
Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious
Diseases, National Institutes of Health, Room 126, Building 4, Center Dr. MSC
0425, 20892-0425, Bethesda, MD, USA
The present studies were designed to examine the requirements of dose, route of
inoculation and constituent antigens for the maintenance of complete and long
lasting protection against cutaneous leishmaniasis due to Leishmania major
conferred by a cocktail DNA vaccine encoding the Leishmania antigens LACK,
LmST11 and TSA. Vaccination of C57Bl/6 mice with LACK DNA alone resulted in
partial protection, whereas the combination of LmST11 and TSA provided stronger,
though still incomplete protection compared to the combination of all three Ag
DNAs. When intradermal (i.d), intramuscular (i.m.), and subcutaneous (s.c.)
vaccination routes were compared, i.d. immunization reduced by five-fold the
dose necessary to maintain complete protection. In vivo depletion of CD4+ or
CD8+ T cells provided direct evidence that both populations are necessary to
mediate complete protection. These results establish intradermal vaccination
using DNA encoding multiple Leishmania antigens as a way to optimize priming of
CD4+ and CD8+ T cells necessary for potent and durable protection against
cutaneous leishmaniasis.
====================================================
52.) Canine leishmaniasis: epidemiological risk and the experimental model.
====================================================
Trends Parasitol 2002 Sep;18(9):399-405
Moreno J, Alvar J.
WHO Collaborating Centre for Leishmaniasis, Servicio de Parasitologi;a, Centro
Nacional de Microbiologia, Instituto de Salud Carlos III, Ctra.
Majadahonda-Pozuelo km 2, 28220 Majadahonda, Spain.
Increasing risk factors are making zoonotic visceral leishmaniasis a growing
public health concern in many countries. Domestic dogs constitute the main
reservoir of Leishmania infantum and Leishmania chagasi, and play a key role in
the transmission to humans. New reagents and tools allow the detailed
investigation of canine leishmaniasis, permitting the monitoring of the
immunological status of dogs in both natural and experimental infections. Such
studies are essential to determine the basis of the canine protective immune
response and to establish a laboratory model, a significant aspect for the
development of vaccines against canine leishmaniasis.
====================================================
53.) Protective efficacy of a tandemly linked, multi-subunit recombinant
leishmanial vaccine (Leish-111f) formulated in MPL adjuvant.
====================================================
Skeiky YA, Coler RN, Brannon M, Stromberg E, Greeson K, Crane RT, Campos-Neto A,
Reed SG.
Corixa Corporation, 1124 Columbia Street, Suite 200, Seattle, WA 98104, USA.
[email protected]
Three immunodominant leishmanial antigens (TSA, LmSTI1 and LeIF) previously
identified in the context of host response to infection in infected donors and
BALB/c mice, as well as their ability to elicit at least partial protection
against Leishmania major infection in the BALB/c mouse model, were selected for
inclusion into a subunit based vaccine. This is based on the premise that an
effective vaccine against leishmaniasis (a complex parasitic infection) would
require a multivalent cocktail of several antigens containing a broader range of
protective epitopes that would cover a wide range of MHC types in a
heterogeneous population. For practical considerations of vaccine development,
we report on the generation of a single recombinant polyprotein comprising the
sequences of all three open reading frames genetically linked in tandem. The
resulting molecule, Leish-111f, comprises an open reading frame that codes for a
111kDa polypeptide. Evaluation of the immunogenicity and protective efficacy of
Leish-111f formulated with IL-12 revealed that the immune responses to the
individual components were maintained and as well, rLeish-111f protected BALB/c
mice against L. major infection to a magnitude equal or superior to those seen
with any of the individual components of the vaccine construct or SLA, a soluble
Leishmania lysate. But because rIL-12 is expensive and difficult to manufacture
and its efficacy and safety as an adjuvant for human use is questionable, we
screened for other adjuvants that could potentially substitute for IL-12. We
report that monophosphoryl lipid A (MPL) plus squalene (MPL-SE) formulated with
rLeish-111f elicited protective immunity against L. major infection. The
demonstrated feasibility to manufacture a single recombinant vaccine comprising
multiple protective open reading frames and the potential use of MPL-SE as a
substitute for IL-12, takes us closer to the realization of an affordable and
safe Leishmania vaccine.
====================================================
54.) Molecular biological applications in the diagnosis and control of
leishmaniasis and parasite identification.
====================================================
Trop Med Int Health 2002 Aug;7(8):641-51 Related Articles, Links
Schallig HD, Oskam L.
Koninklijk Instituut voor de Tropen (KIT), Biomedical Research, Amsterdam, The
Netherlands. [email protected]
Molecular biology is increasingly relevant to the diagnosis and control of
infectious diseases. Information on DNA sequences has been extensively exploited
for the development of polymerase chain reaction-based assays for the diagnosis
of leishmaniasis and the identification of parasite species. It has also led to
the use of cloned antigen for serodiagnosis. It is expected that the sequencing
of the Leishmania major genome and the genomes of other Leishmania species will
enable important progress in further improving diagnosis and control. The
ability to use genome data to clone and sequence genes, which, when expressed,
provide antigens for vaccine development, will increase the possibilities for
rational vaccine development. Moreover, DNA on its own will provide the basis
for the development of DNA vaccines that may overcome some of the problems
encountered with protein-based vaccines. One of the greatest threats to parasite
control is the development of drug resistance in parasites. Knowing the
molecular basis of drug resistance and the ability to monitor its development
with sensitive and specific DNA-based assays for 'resistance alleles' may aid
maintaining the effectiveness of available anti-Leishmania drugs. Finally,
techniques such as microarrays and nucleic acid sequence-based amplification
will eventually allow rapid screening for specific parasite genotypes and assist
in diagnostic and epidemiological studies.
====================================================
55.) Immunochemotherapy in American cutaneous leishmaniasis: immunological
aspects before and after treatment.
====================================================
Mem Inst Oswaldo Cruz 2001 Jan;96(1):89-98 Related Articles, Links
Toledo VP, Mayrink W, Gollob KJ, Oliveira MA, Costa CA, Genaro O, Pinto JA,
Afonso LC.
Departamento de Analises Clinicas e Toxicologicas, Faculdade de Farmacia,
Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brasil.
In this study, we evaluated the immune response of patients suffering from
cutaneous leishmaniasis treated with two distinct protocols. One group was
treated with conventional chemotherapy using pentavalent antimonium salts and
the other with immunochemotherapy where a vaccine against cutaneous
leishmaniasis was combined with the antimonium salt. Our results show that,
although no differences were observed in the necessary time for complete healing
of the lesions between the two treatments, peripheral blood mononuclear cells
from patients treated by chemotherapy showed smaller lymphoproliferative
responses at the end of the treatment than those from patients in the
immunochemotherapy group. Furthermore, IFN-gamma production was also different
between the two groups. While cells from patients in the chemotherapy group
produced more IFN-gamma at the end of treatment, a significant decrease in this
cytokine production was associated with healing in the immunochemotherapy group.
In addition, IL-10 production was also less intense in this latter group.
Finally, an increase in CD8+ -IFN-gamma producing cells was detected in the
chemotherapy group. Together these results point to an alternative treatment
protocol where healing can be induced with a decreased production of a
potentially toxic cytokine.
====================================================
56.) T cell responses to crude and defined leishmanial antigens in patients from
the lower Amazon region of Brazil infected with different species of Leishmania
of the subgenera Leishmania and Viannia.
====================================================
Parasite Immunol 1998 Jan;20(1):19-26
Silveira FT, Blackwell JM, Ishikawa EA, Braga R, Shaw JJ, Quinnell RJ, Soong L,
Kima P, McMahon-Pratt D, Black GF, Shaw MA.
Instituto Evandro Chagas (FNS), Belem, Para, Brazil.
Amazonian localized cutaneous leishmaniasis (LCL) is caused by parasites of the
subgenera Leishmania and Viannia. Respectively, these parasites may cause
diffuse cutaneous leishmaniasis (DCL) and mucocutaneous leishmaniasis (MCL).
This, together with differing skin test responses, suggests some
species-specificity in cell mediated immunity. In this study, T cell responses
(proliferative and interferon-gamma) to crude and defined antigens were examined
in paired samples pre and post chemotherapy. Untreated L. (L.) amazonensis LCL
patients showed lower responses to crude leishmanial antigens than the L. (V.)
spp. group. L. (V.) braziliensis antigen was a more potent stimulator of T cell
responses than L. (L.) amazonensis antigen in all patient groups. Few positive
responses were seen to the L. (L.) amazonensis glycoprotein GP46. A substantial
proportion of LCL patients did respond to the L. (L.) pifanoi amastigote
antigens A2, and the surface membrane glycoprotein P8. DCL patients were poor
responders to all leishmanial antigens, except GP46. In contrast, MCL patients
were good responders to all antigens except GP46 and A2. A significant rise in
the response to P8 and A2 antigen was seen post treatment across all LCL and MCL
patients, indicating that these antigens might provide suitable vaccine
candidates.
====================================================
57.) Cell-mediated immunity in localized cutaneous leishmaniasis patients before
and after treatment with immunotherapy or chemotherapy.
====================================================
Parasite Immunol 1989 May;11(3):211-22
Castes M, Moros Z, Martinez A, Trujillo D, Castellanos PL, Rondon AJ, Convit J.
Instituto de Biomedicina, Facultad de Medicina, Universidad Central de
Venezuela, Caracas.
In previous studies of the treatment of localized cutaneous leishmaniasis (LCL)
we demonstrated that the therapeutic efficiency of immunotherapy (BCG plus
promastigotes of Leishmania mexicana) is equal to that of chemotherapy
(Glucantime), without causing the serious side-effects of the drug treatment. In
the present study, various aspects of cell-mediated immunity, including the
lymphoproliferative response, and leucocyte subpopulations were evaluated both
before treatment and after cure in 39 LCL patients who had received
immunotherapy (IT), in 34 submitted to chemotherapy (CT), and in 14 patients
cured by the administration of BCG alone. We demonstrated evident signs of
T-cell activation in cured patients who had received either CT or IT. For
example, an increased expression of IL-2 receptors was observed in such
patients, compared to their pretreatment values. Also, a significant percentage
of patients showed augmented in-vitro responses to mitogen, and both in-vitro
and in-vivo reactivity to leishmanial antigen. No evidence was found for the
development of an exaggerated immune response to Leishmania parasites in the IT
group, because the final level of immunological reactivity was comparable to the
CT group. Neither was there any difference in terms of the final immune response
between the patients cured by BCG treatment alone and the other groups. However,
the therapeutic efficiency of BCG was lower and the mean cure time was longer.
We conclude that IT is very useful in the treatment of LCL patients because of
its high efficiency, low propensity to produce side-effects, and the fact that
it does not induce a state of hyper-reactivity.
====================================================
58.) Immunotherapy as a treatment of American cutaneous leishmaniasis:
preliminary studies in Brazil.
====================================================
Parassitologia 1992 Dec;34(1-3):159-65
Mayrink W, Magalhaes PA, Michalick MS, da Costa CA, Lima Ade O, Melo MN, Toledo
VP, Nascimento E, Dias M, Genaro O, et al.
Departamento de Parasitologia, Universidade Federal de Minas Gerais, Belo
Horizonte, Brasil.
A prophylactic vaccine composed of killed promastigotes of five stocks of
Leishmania was tested as an immunotherapeutic agent against American cutaneous
leishmaniasis (ACL). The agent was administered by deep intramuscular injection
daily for 10 days, followed by a 10-day interval. Out of 62 patients so treated,
47 (76%) were considered clinically cured; 41 required 2-10 treatment courses
and the other six 11-19 courses. None of the patients treated by immunotherapy
displayed adverse side-effects. Immunotherapy proved to be effective in the
treatment of single cutaneous lesions, multiple cutaneous lesions and in cases
of mucocutaneous leishmaniasis. In comparison with chemotherapy (Glucantime),
immunotherapy is less efficient and more prolonged but can be safely used when
antimonials are contra-indicated or are found to be ineffective. Consideration
is given to the treatment of victims of ACL living in rural areas remote from a
medical centre.
====================================================
59.) T-cell responsiveness of American cutaneous leishmaniasis patients to
purified Leishmania pifanoi amastigote antigens and Leishmania braziliensis
promastigote antigens: immunologic patterns associated with cure.
====================================================
Exp Parasitol 1996 Nov;84(2):144-55
Coutinho SG, Oliveira MP, Da-Cruz AM, De Luca PM, Mendonca SC, Bertho AL, Soong
L, McMahon-Pratt D.
Department of Protozoology, Oswaldo Cruz Institute-FIOCRUZ, Rio de Janeiro,
Brasil.
Patients suffering from American cutaneous leishmaniasis were studied before
therapy (active lesion) and at the end of therapy (cured patients). Assays of
lymphocyte proliferative responses of peripheral blood mononuclear cells induced
in vitro by Leishmania braziliensis promastigote antigens (Lb) or by three
proteins (A-2/P-2, P-4, and P-8) derived from Leishmania pifanoi amastigotes
were performed. Antigen-stimulated cells were harvested for CD4 and CD8
phenotype analysis and the levels of gamma interferon (IFN-gamma), interleukin 2
(IL-2) and interleukin 4 (IL-4) produced were also determined. Results show two
different patterns of Lb-induced T cell responses: (a) predominance of
responding CD4+ cells and mixed type 1 and type 2 cytokine production
(IFN-gamma, IL-2, and IL-4) during the active disease, (b) similar proportions
of responding CD4+ and CD8+ cells and type 1 cytokine production (presence of
IFN-gamma and IL-2 and very low IL-4) at the end of therapy (healed lesions).
Thus, this last pattern is probably associated with a beneficial T cell
response. The A-2/P-2 amastigote cysteine proteinase provided only marginal
(s.i. approximately or = 2.5) T cell stimulation in 25% of patients studied; in
contrast, the L. pifanoi P-4 and P-8 amastigote antigens induced significant
stimulation (s.i. approximately or = 5) in approximately 50% of the patients. In
comparison to Lb-stimulated cultures, lower proliferative responses of T
lymphocytes to P-4 or P-8 were observed. However, the P-4- or P-8-stimulated
cultures had similar percentages of reactive CD4+ and CD8+ cells, as well as
type 1 cytokines (presence of IFN-gamma and IL-2, and low levels or absence of
IL-4) in the supernatants both before and at the end of therapy. The consistent
induction of apparently beneficial T cell responses by the P-4 and P-8
amastigote glycoproteins points to the possibility that these molecules be
considered as candidates for future defined vaccines against leishmaniasis.
====================================================
60.) Dichotomy of the T cell response to Leishmania antigens in patients
suffering from cutaneous leishmaniasis; absence or scarcity of Th1 activity is
associated with severe infections.
====================================================
Clin Exp Immunol 1995 May;100(2):239-45
Gaafar A, Kharazmi A, Ismail A, Kemp M, Hey A, Christensen CB, Dafalla M, el
Kadaro AY, el Hassan AM, Theander TG.
Institute of Tropical Medicine, MRC, Khartoum, Sudan.
The T cell response was studied in 25 patients suffering from cutaneous
leishmaniasis caused by Leishmania major with severe (n = 10) and mild (n = 15)
disease manifestations. Peripheral blood mononuclear cells (PBMC) from the
patients were activated by sonicates of Leishmania promastigotes (LMP) and
amastigotes (LDA), and the surface protease gp63. The proliferative responses to
Leishmania antigens were lower in patients with severe disease than in patients
with mild disease (P = 0.01-0.05), and such a difference was not observed in the
response to purified protein derivative of tuberculin (PPD) or tetanus toxoid
(TT). LMP-induced interferon-gamma (IFN-gamma) production was lower in patients
with severe than in patients with mild disease (P < 0.05). When the IL-4 and
IFN-gamma responses of each patient were considered, two response patterns were
observed in the cultures activated by the Leishmania sonicates. One response
pattern was characterized by high production of IFN-gamma without production of
IL-4 (a Th1-like pattern), the other was characterized by low IFN-gamma levels
which in most cases were associated with IL-4 production (not a Th1-like
pattern). These patterns could not be distinguished when the cells from the same
donors were stimulated by TT and PPD. The percentages of patients with a
Th1-like response pattern after stimulation by LMP in patients with severe and
mild disease manifestations were 30% and 80%, respectively. This difference was
statistically significant (P = 0.034).
====================================================
61.) Chemotherapy for cutaneous leishmaniasis: a controlled trial using killed
Leishmania (Leishmania) amazonensis vaccine plus antimonial.
====================================================
Int J Dermatol 2002 Feb;41(2):73-8
Machado-Pinto J, Pinto J, da Costa CA, Genaro O, Marques MJ, Modabber F, Mayrink
W.
Department of Dermatology, Santa Casa Hospital, Federal University of Minas
Gerais, Belo Horizonte, Brazil. [email protected]
BACKGROUND: Leishmaniasis is endemic in 88 countries in the world, and 350
million individuals are at risk of acquiring the disease. Treatment for American
cutaneous leishmaniasis (ACL) is long, expensive, and associated with important
side-effects. METHODS: In this double-blind, placebo-controlled study, we
treated 102 patients with ACL using either a combination of a single-strain
Leishmania amazonensis killed promastigote vaccine plus a half dose of meglumine
antimoniate, or placebo plus the same half dose regimen of meglumine
antimoniate, in 10-day series followed by 10-day intervals. RESULTS: Of the 47
patients in the experimental arm, 47 (100%) were cured after four series of
treatment, compared to four of 49 (8.2%) in the control group (P < 0.0001). Six
patients were lost to follow-up. CONCLUSIONS: The combination of a single-strain
Leishmania (Leishmania) amazonensis killed promastigote vaccine with a half dose
regimen of antimonial is highly effective for the treatment of ACL.
====================================================
62.) Immunotherapy versus chemotherapy in localised cutaneous leishmaniasis.
====================================================
Lancet 1987 Feb 21;1(8530):401-5 Related Articles, Links
Convit J, Castellanos PL, Rondon A, Pinardi ME, Ulrich M, Castes M, Bloom B,
Garcia L.
In a randomised trial a combination vaccine consisting of live BCG together with
killed leishmania promastigotes was compared with a standard antimonial regimen
in 94 patients with localised cutaneous leishmaniasis. Three vaccinations over
32 weeks gave a similar cure rate (94%) to three 20-day courses of meglumine
antimonate. In the immunotherapy group side-effects were few (5.8%) and slight
whereas in the chemotherapy group they were frequent (52.4%) and often serious.
Immunotherapy is a low-cost, low-risk alternative to chemotherapy in localised
cutaneous leishmaniasis, applicable by primary health services in rural areas.
====================================================
63.)Immunotherapy of localized, intermediate, and diffuse forms of American
cutaneous leishmaniasis.
====================================================
J Infect Dis 1989 Jul;160(1):104-15
Convit J, Castellanos PL, Ulrich M, Castes M, Rondon A, Pinardi ME, Rodriquez N,
Bloom BR, Formica S, Valecillos L, et al.
Instituto de Biomedicina, Caracas, Venezuela.
The clinical efficacy of immunotherapy for localized American cutaneous
leishmaniasis with a combination of heat-killed Leishmania mexicana amazonensis
promastigotes and viable BCG (bacille Calmette Guerin) has been compared with
meglumine antimoniate chemotherapy and with BCG alone in a controlled clinical
study in 217 patients. The results in the first two groups were comparable, with
greater than 90% clinical cures with an average time of 16-18 w required for
healing. The cure rate was considerably lower (42%) and more prolonged in the
group receiving BCG alone. Secondary effects were observed in less than 5% of
the patients receiving combined immunotherapy or BCG alone. In contrast, 49% of
the patients receiving chemotherapy showed side effects. High therapeutic
efficacy was also observed using combined immunotherapy in patients with
intermediate and diffuse cutaneous leishmaniasis who were previously
unresponsive to chemotherapy. Cure or clinical improvement was seen in all 11
patients with intermediate forms of the disease, and marked clinical improvement
was observed in 9 of 10 patients with diffuse disease. The results on the
efficacy of the combined vaccine in immunotherapy for American cutaneous
leishmaniasis provide a strong rationale for studying its effectiveness in
prophylactic trials.
====================================================
64.) Characterization of the immune response in subjects with self-healing
cutaneous leishmaniasis.
====================================================
Am J Trop Med Hyg 1995 Sep;53(3):273-7
Carvalho EM, Correia Filho D, Bacellar O, Almeida RP, Lessa H, Rocha H.
Servico de Imunologia do Hospital Universitario Prof. Edgard Santos, Faculdade
de Medicina da Universidade Federal da Bahia, Salvador, Bahia, Brazil.
In patients with cutaneous leishmaniasis in areas of Leishmania braziliensis
transmission, ulcers may heal without therapy. In the present study, we
evaluated the T cell responses of 10 subjects who two years earlier had a
rapidly (less than three months) self-healing cutaneous disease. The immunologic
responses of these cases were determined by intradermal skin test, measurements
of antibodies, lymphocyte proliferative responses, and interferon-gamma
(IFN-gamma) production in cultures stimulated with Leishmania antigens. These
data were compared with those observed in 10 other patients with active
cutaneous and mucosal leishmaniasis. Evidence of strong lymphocyte blastogenesis
and IFN-gamma production was observed in eight of 10 patients with self-healing
cutaneous leishmaniasis, with stimulation indices ranging from 32 to 506, and
IFN-gamma levels ranging from 500 to 2,900 pg/ml. The mean +/- SD stimulation
index of the lymphocyte proliferative responses (288 +/- 247) and the mean +/-
SD of IFN-gamma production after stimulation with Leishmania antigen (970 +/-
960 pg/ml) in subjects with self-healing cutaneous leishmaniasis were similar (P
> 0.05) to those observed in patients with mucosal disease (stimulation index =
308 +/- 282 and IFN-gamma level = 838 +/- 819 pg/ml). These responses were
higher (P < 0.01) than those observed in patients with active cutaneous
leishmaniasis (stimulation index = 50 +/- 82 and IFN-gamma level = 264 +/- 336
pg/ml).(ABSTRACT TRUNCATED AT 250 WORDS)
====================================================
65.) Antigen provoking gamma interferon production in response to Mycobacterium
bovis BCG and functional difference in T-cell responses to this antigen between
viable and killed BCG-immunized mice.
====================================================
Infect Immun 1994 Oct;62(10):4396-403
Kawamura I, Yang J, Takaesu Y, Fujita M, Nomoto K, Mitsuyama M.
Department of Bacteriology, Niigata University School of Medicine, Japan.
It has been shown that gamma interferon (IFN-gamma)-producing CD4+ T cells,
which are generated only by immunization with viable bacteria, exert a
significant role in protective immunity against mycobacteria in mice. In this
study, we have tried to determine the antigen recognized by the T cells in
search of a possible protective antigen. T cells from viable Mycobacterium bovis
BCG-immunized mice were stimulated with several antigens, and IFN-gamma
production was measured. Purified protein derivative and viable and killed BCG
lysates caused significant IFN-gamma production, and almost the same level of
IFN-gamma activity was detected in both groups stimulated with viable and killed
BCG lysates. However, heat shock protein (HSP) 65 and HSP 70 were not a major
antigen for IFN-gamma production. The antigen provoking IFN-gamma production is
localized mainly in the membrane fraction of BCG cells, and the approximate
molecular size was 18 kDa. On the other hand, T cells from killed BCG-immunized
mice never responded to this antigen for IFN-gamma production, whereas they
could mount a delayed-type hypersensitivity response. These results showed that
the antigen provoking IFN-gamma production was present in killed as well as
viable BCG. In addition to the antigen presentation by antigen-presenting cells,
some kinds of differentiation factor (such as monokines) that are produced only
by stimulation with viable cells seemed to be necessary for the development of
IFN-gamma-producing T cells.
====================================================
66.) Autoclaved Leishmania major vaccine for prevention of visceral
leishmaniasis: a randomised, double-blind, BCG-controlled trial in Sudan.
====================================================
Lancet 2000 Nov 4;356(9241):1565-9
Khalil EA, El Hassan AM, Zijlstra EE, Mukhtar MM, Ghalib HW, Musa B, Ibrahim ME,
Kamil AA, Elsheikh M, Babiker A, Modabber F.
Leishmaniasis Research Group/Sudan, Institute of Endemic Diseases, Khartoum.
<[email protected]
BACKGROUND: Visceral leishmaniasis is a major cause of morbidity and mortality
in the Sudan. Drug treatment is expensive, and drug resistance is becoming
increasingly common. Safe, effective, and cheap vaccines are needed. We report
the results of a vaccine trial against human visceral leishmaniasis. METHODS: We
undertook a double-blind randomised trial to test the safety and efficacy of an
autoclaved Leishmania major (ALM) promastigote vaccine (1 mg per dose). Of 5093
volunteers screened, 2306 had negative leishmanin skin tests and reciprocal
titres of less than 6400 in the direct agglutination test. They were randomly
assigned two doses of ALM mixed with BCG or BCG alone. Volunteers were followed
up for 2 years. The primary endpoint was clinical visceral leishmaniasis or
post-kala-azar dermal leishmaniasis. Analyses were by intention to treat.
FINDINGS: Side-effects were confined to the injection site. The cumulative
frequency of visceral leishmaniasis at 2 years did not differ significantly
between the group assigned ALM plus BCG and that assigned BCG alone (133/1155
[11.5%] vs 141/1151 [12.3%], p=0.6). The vaccine efficacy was 6% (95% CI -18 to
25). The proportion of individuals showing leishmanin skin conversion was
significantly higher in the ALM plus BCG group than in the BCG alone group
throughout follow-up (303 [30%] vs 72 [7%] at 42 days). Individuals whose
leishmanin test converted after vaccination (induration > or =5 mm) had a
significantly lower frequency of visceral leishmaniasis than non-responders
(27/375 [7.2%] vs 210/1660 [12.7%], p=0.003). INTERPRETATION: We found no
evidence that two doses of ALM plus BCG offered significant protective immunity
against visceral leishmaniasis compared with BCG alone. Leishmanin skin
conversion with an induration of 5 mm or more in either group was associated
with protection from the disease.
====================================================
67.) Leishmania donovani p36(LACK) DNA vaccine is highly immunogenic but not
protective against experimental visceral leishmaniasis.
====================================================
Infect Immun 2001 Aug;69(8):4719-25
Melby PC, Yang J, Zhao W, Perez LE, Cheng J.
Medical Service, Department of Veterans Affairs Medical Center, South Texas
Veterans Health Care System, University of Texas Health Science Center, San
Antonio, Texas 78229-3900, USA. [email protected]
The acquisition of immunity following subclinical or resolved infection with the
intracellular parasite Leishmania donovani suggests that vaccination could
prevent visceral leishmaniasis (VL). The LACK (Leishmania homolog of receptors
for activated C kinase) antigen is of interest as a vaccine candidate for the
leishmaniases because of its immunopathogenic role in murine L. major infection.
Immunization of mice with a truncated (24-kDa) version of the 36-kDa LACK
antigen, delivered in either protein or DNA form, was found previously to
protect against cutaneous L. major infection by redirecting the early T-cell
response away from a pathogenic interleukin-4 (IL-4) response and toward a
protective Th1 response. The amino acid sequence of the Leishmania p36(LACK)
antigen is highly conserved, but the efficacy of this vaccine antigen in
preventing disease caused by strains other than L. major has not been
determined. We investigated the efficacy of a p36(LACK) DNA vaccine against VL
because of the serious nature of this form of leishmaniasis and because it was
unclear whether the LACK vaccine would be effective in a model where there was
not a dominant pathogenic IL-4 response. We demonstrate here that although the
LACK DNA vaccine induced a robust parasite-specific Th1 immune response
(IFN-gamma but not IL-4 production) and primed for an in vivo T-cell response to
inoculated parasites, it did not induce protection against cutaneous or systemic
L. donovani challenge. Coadministration of IL-12 DNA with the vaccine did not
enhance the strong vaccine-induced Th1 response or augment a protective effect.
====================================================
68.) Vaccination of Balb/c mice against experimental visceral leishmaniasis with
the GP36 glycoprotein antigen of Leishmania donovani.
====================================================
Vaccine 2001 Apr 30;19(23-24):3104-15
Paraguai de Souza E, Bernardo RR, Palatnik M, Palatnik de Sousa CB.
Instituto de Microbiologia, Prof. Paulo de Goes, Universidade Federal do Rio de
Janeiro (UFRJ), CCS, Cidade Universitaria, Ilha do Fundao, CP 68040. CEP
21941-590., Rio de Janeiro, Brazil.
Leishmania donovani GP36 glycoprotein is the main antigen of the FML Fucose
Mannose Ligand (FML) complex specifically recognized by sera of kala-azar human
patients. The GP36 was isolated by chemical elution + sonication and used for
Balb/c mouse vaccination in combination with saponin, by the s.c. route,
inducing a strong and specific protective effect against experimental visceral
leishmaniasis shown by the increase of: specific IgG antibodies (82.6%), mainly
IgG2a, the delayed type of hypersensitivity to promastigote lysate (37.8%, P <
0.001), the in vitro cellular proliferative response to GP36 of ganglia
lymphocytes (53.5%, P < 0.005) and the decrease of liver parasite burden (68.1%,
P < 0.025). Saponin treated controls reacted significantly differently from GP36
vaccinated animals at all the assayed variables (P < 0.05). GP36 induced
significant protection against murine visceral leishmaniasis at concentrations
commonly used for vaccination with recombinant antigens.
====================================================
69.) Vaccination of langur monkeys (Presbytis entellus) against Leishmania
donovani with autoclaved L. major plus BCG.
====================================================
Parasitology 1998 Mar;116 ( Pt 3):219-21
Dube A, Sharma P, Srivastava JK, Misra A, Naik S, Katiyar JC.
Division of Parasitology, Central Drug Research Institute, Lucknow, India.
[email protected]
The protective potential of killed Leishmania major (ALM) along with BCG was
evaluated against L. donovani in Indian langur monkeys in single and triple dose
schedules. A delayed protection was observed in monkeys after a single dose
schedule of ALM (3 mg)+BCG (3 mg) given intradermally 2 months before
intravenous challenge with L. donovani. Triple dose schedule each of 1 mg ALM +
1 mg BCG was more effective. The status remained unchanged until the end of the
experiment (approximately 8 months). The study indicates that a combination of
ALM + BCG may be a good candidate vaccine for exploiting against human
Kala-azar.
====================================================
70.) Successful vaccination against Leishmania donovani infection in Indian
langur using alum-precipitated autoclaved Leishmania major with BCG.
====================================================
Vaccine 2001 May 14;19(25-26):3485-92
Misra A, Dube A, Srivastava B, Sharma P, Srivastava JK, Katiyar JC, Naik S.
Division of Parasitology, Central Drug Research Institute, P.O. Box 173, 226001,
Lucknow, India.
Autoclaved Leishmania major (ALM) along with BCG, presently undergoing phase II
clinical trial by WHO for its vaccine potential against cutaneous leishmaniasis,
has been successfully evaluated in single and triple dose schedules against L.
donovani in Indian langurs (Presbytis entellus). Encouraged with the results,
another formulation alum-precipitated ALM (provided by WHO) along with BCG has
been evaluated in this system. Eight monkeys were vaccinated with
alum-precipitated ALM + BCG (1 mg of each per animal) while four were kept as
unvaccinated controls. All were challenged with 100 x 10(6) amastigotes i.v. on
day 60 post vaccination. Parasitic assessment in splenic tissue was performed on
day 45, 90 and 180 p.c. Initially, seven of the eight vaccinated monkeys
developed infection (two to six amastigotes per 1000 cell nuclei), which
resolved by day 180 p.c., while the eighth monkey had a parasite burden of 14
amastigotes per 1000 cell nuclei on day 45 p.c. and died on day 130 p.c. On the
other hand, there was progressive infection in unvaccinated control animals and
three out of four died between days 110 and 120 p.c., and one monkey, which had
low parasite burden, died on day 178 p.c. Prior to challenge, there was an
initial rise in antileishmanaial antibodies in the vaccinated group compared to
the unvaccinated control group, which later came down to normal level, while it
remained higher in the unvaccinated control group. An increasing pattern of
antigen-specific proliferative responses and interferon-gamma level to the two
antigens--autoclaved L. donovani (ALD) and ALM--was observed in vaccinated
monkeys throughout the experiment. There was a good correlation between parasite
burden and IFN-gamma level on days 90 and 180 p.c., indicating IFN-gamma
response as a sensitive parameter of immune status. The findings suggest
alum-precipitated ALM+BCG as a potential vaccine against visceral leishmaniasis
and warrants clinical trials.
====================================================
71.) [Protective effects of leishmanial antigens against Leishmania infantum
infection in Lagurus lagurus]
====================================================
Zhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi 1999;17(4):237-40
[Article in Chinese]
Chai J, Chang KP, Zuo X, Yan L, Hou Y, Zhang S, Ruziguli, Jiang W, Zhang L.
National Hydatid Disease Centre of China, Institute for Endemic Diseases Control
and Research of Xinjiang Uygur Autonomous Region, Urumqi, Xinjiang 83000.
AIM: To determine the protective effect of leishmanial surface antigens against
experimental visceral leishmaniasis in Lagurus lagurus caused by Leishmania
infantum. METHODS: Recombinant surface protein (rGP63) and lipophosphoglycan
(LPG) of Leishmania were used with Corinebacterium parum vaccine as ajuvant to
immunize Lagurus lagurus against a challenge with virulent strain of Leishmania
infantum. The efficacy of immunoprotection was observed. RESULTS: When
challenged with up to 2 x 10(7) promastigotes, the number of LD on the liver
printing sections in the rGP63 + LPG + CP immunised animals was significantly
decreased, the parasite reduction rate being 89.79%. LPG + CP gave a parasite
reduction rate of 60.6% and rGP63/beta-galactosidase fusion protein + CP showed
a parasite reduction rate of 42.45%. Purified rGP63 showed no protection.
Immunization with rGP63 + LPG + CP followed by challenge inifection with 1 x
10(6), 5 x 10(6) and 1 x 10(7) promastigotes also showed significantly reduced
infection rates. CONCLUSION: A combination of rGP63 + LPG + CP antigens could
provide significant immunoprotection against L. infantum challenge in L.
lagurus.
====================================================
72.) Vaccination with DNA encoding ORFF antigen confers protective immunity in
mice infected with Leishmania donovani.
====================================================
Vaccine 2003 Mar 7;21(11-12):1292-9
Sukumaran B, Tewary P, Saxena S, Madhubala R.
School of Life Sciences, Jawaharlal Nehru University, 110067, New Delhi, India
The gene ORFF is part of the multigenic LD1 locus on chromosome 35 that is
frequently amplified in Leishmania. The function of ORFF is unknown. The gene
encoding ORFF was cloned into a eukaryotic expression vector downstream to the
cytomegalovirus (CMV) promoter. BALB/c mice were injected intramuscularly with
ORFF DNA and challenged with Leishmania donovani promastigotes. Vaccination with
ORFF gene induced both humoral and cellular immune response against ORFF, which
provided significant level of protection against challenge with L. donovani. A
qualitative PCR was used to determine whether activation of Th1 cells develops
selectively in response to this ORFF DNA vaccine. The results indicated that
mRNA for IFN-gamma was significantly induced in immunized mice. No significant
change in IL-4 mRNA expression was observed in mice immunized with ORFF DNA
vaccine versus mice immunized with control plasmid. Thus, DNA immunization may
offer an attractive alternative strategy against leishmaniasis.
====================================================
73.) Intradermal infection model for pathogenesis and vaccine studies of murine
visceral leishmaniasis.
====================================================
Infect Immun 2003 Jan;71(1):401-10
Ahmed S, Colmenares M, Soong L, Goldsmith-Pestana K, Munstermann L, Molina R,
McMahon-Pratt D.
Department of Epidemiology and Public Health, Yale University School of
Medicine, New Haven, Connecticut 06520-8034, USA.
The levels of protection found in vaccine studies of murine visceral
leishmaniasis are significantly lower than for cutaneous leishmaniasis; whether
this is due to the high-challenge murine model employed and/or is a consequence
of differences required in tissue-specific local immune responses is not
understood. Consequently, an intradermal murine model of visceral leishmaniasis
has been explored. Intradermal inoculation established a chronic infection in
susceptible mice which was associated with a pattern of parasite clearance with
time postinfection in the liver and skin; in contrast, parasite persistence and
expansion was observed in lymphoid tissue (spleen and draining lymph node). The
course of disease found appears to be similar to those reported for subclinical
canine and human visceral leishmaniasis. Clearance of parasites from the skin
was correlated with an inflammatory response and the infiltration and activation
of CD4(+) and CD8(+) T cells. In contrast, in lymphoid tissue (lymph node or
spleen), the production of Th1/Th2 cytokines (interleukin-4 [IL-4], IL-10, and
gamma interferon) appeared to correlate with parasite burden and pathogenesis.
In vaccination experiments employing the Leishmania infantum D-13 (p80) antigen,
significantly higher levels of protection were found with the intradermal murine
model (29 to 7,500-fold more than naive controls) than were found with a
low-dose intravenous infection model (9 to 173-fold). Thus, this model should
prove useful for further investigation of disease pathogenesis as well as
vaccine studies of visceral leishmaniasis.
====================================================
74.) Saponins, IL12 and BCG adjuvant in the FML-vaccine formulation against
murine visceral leishmaniasis.
====================================================
Vaccine 2002 Nov 22;21(1-2):30-43
Santos WR, de Lima VM, de Souza EP, Bernardo RR, Palatnik M, de Sousa CB.
Instituto de Microbiologia, "Professor Paulo de Goes" Universidade Federal do
Rio de Janeiro (UFRJ), CCS, Cidade Universitaria, Ilha do Fundao, Caixa Postal
68040, CEP 21941-590, RJ, Rio de Janeiro, Brazil
The FML antigen of Leishmania donovani, in combination with either Riedel de
Haen (R), QuilA, QS21 saponins, IL12 or BCG, was used in vaccination of an
outbred murine model against visceral leishmaniasis (VL). Significant and
specific increases in anti-FML IgG and IgM responses were detected for all
adjuvants, and in anti-FML IgG1, IgG2a and IgG2b and delayed type of
hypersensitivity to L. donovani lysate (DTH), only for all saponins and IL12.
The QS21-FML and QuilA-FML groups achieved the highest IgG2a response. QuilA-FML
developed the strongest DTH and QS21-FML animals showed the highest serum
IFN-gamma concentrations. The reduction of parasitic load in the liver in
response to each FML-vaccine formulation was: 52% (P<0.025) for BCG-FML, 73%
(P<0.005) for R-FML, 93% (P<0.005) for QuilA-FML and 79.2% (P<0.025) for
QS21-FML treated animals, respectively. Protection was specific for R-FML and
QS21-FML while the QuilA saponin treatment itself induced 69% of LDU reduction.
The FML-saponin vaccines promote significant, specific and strong protective
effects against murine visceral leishmaniasis. BCG-FML induced minor and
non-specific protection while IL12-FML, although enhancing the specific antibody
and IDR response, failed to reduce the parasitic load of infected animals.
====================================================
75.) COMPONENT OF FLY SALIVA MAKES PROMISING LEISHMANIASIS VACCINE
====================================================
Source: www.niaid.nih.gov/ 06 august 2.001
Researchers seeking to make a vaccine against a serious parasitic infection have
discovered a dose of fly saliva might be just what the doctor ordered.
Leishmaniasis, a disabling and sometimes deadly tropical illness, is caused by a
parasite transmitted to people through the bite of a sand fly. In a report
released today, scientists from the National Institute of Allergy and Infectious
Diseases (NIAID) describe how a vaccine they developed against a component of
sand fly saliva prevents leishmaniasis in mice.
Leishmaniasis, a major health problem in many tropical and desert climates, has
resisted efforts to develop an effective vaccine. "Today's report describes a
novel vaccine," says NIAID Director Anthony S. Fauci, M.D. "Rather than
targeting the parasite, as is typical, our researchers produced a vaccine to the
saliva of the insect that transmits the parasite. This approach could
potentially be used to develop vaccines for other insect- or tick-borne
diseases."
Leishmaniasis refers to a group of related diseases. Different species of the
single-celled parasite Leishmania can cause flesh-eating nose, throat and mouth
infections (mucosal leishmaniasis); painful skin lesions (cutaneous
leishmaniasis); or fatal infestations of the internal organs (visceral
leishmaniasis). An estimated 12 million people currently are affected by one or
more of these diseases, most of whom live in South or Central America, Africa
and the Middle East.
NIAID's José Ribeiro, M.D., Ph.D., an expert on the biochemistry of
blood-feeding bugs, has spent more than 30 years studying how components of
saliva not only help insects and ticks obtain their blood meals but also
modulate the immune response. He and others have previously shown that
laboratory animals immunized with sand fly saliva often resist infection when
later bitten by a Leishmania-carrying insect, or challenged with parasites in
the presence of sand fly saliva. In the new study reported August 6 in the
"Journal of Experimental Medicine", Dr. Ribeiro directed a research team that
sought to use this information to produce a novel vaccine against the disease.
Jesus Valenzuela, Ph.D., Dr. Ribeiro and colleagues examined saliva from the
sand fly carrier of Leishmania major, a parasite species that causes cutaneous
leishmaniasis. The researchers separated the proteins of the saliva and
identified one, dubbed SP15, which appeared to be the target of natural immune
responses in mice. They then worked backwards, using the protein to help them
find its underlying gene.
Once they identified the SP15 gene, Dr. Ribeiro's team used it to construct a
DNA vaccine, which they used to immunize mice. When the immunized mice were
later injected with L. major parasites mixed with fly saliva, the infection was
markedly milder compared to infection in mice that had not been vaccinated. The
immunized mice had much smaller skin lesions, and their infections cleared
within six weeks. Unvaccinated mice developed large skin ulcers and did not
eliminate the parasite.
Because sand fly bites produce both antibodies and T-cell responses, the
researchers analyzed the mice to see which type of immune response was keeping
the parasites in check. When the NIAID team vaccinated "knockout" mice,
genetically engineered not to produce antibodies, the mice were still protected
by the vaccine, suggesting T cells were protecting the animals from disease.
The results demonstrate a vaccine containing a component of sand fly saliva can
protect mice from the severe symptoms associated with cutaneous leishmaniasis,
perhaps by mimicking natural immunity to the infection. "People get bitten by
infected sand flies all the time without developing leishmaniasis," says Dr.
Ribeiro. "It could be that those who develop disease are merely unlucky; they
are bitten by a Leishmania-carrying fly before uninfected flies have had time to
naturally immunize them."
Dr. Ribeiro next plans to test his vaccine in dogs-natural reservoirs of the
parasite-and monkeys. His team also will look at other Leishmania species and
the sand fly species that transmit them, hoping to develop vaccines for other
forms of leishmaniasis. In addition, he has begun to study people who are
naturally exposed to Leishmania to see which components of fly saliva might
protect them from disease. "Different sand fly species, each with its unique
collection of salivary proteins, transmit different Leishmania species," he
explains. "If anti-saliva vaccines are to work in people, they will have to be
specifically engineered for the problem insects of each region."
====================================================
76.) Effort to Target Clinical Development of Corixa's Leishmaniasis Vaccine
====================================================
Source: www.gatesfoundation.org
Infectious Disease Research Institute receives $15 million donation from the
Bill & Melinda Gates Foundation
Contact:
Jesse Ciccone
FitzGerald Communications Inc.
Phone: (415) 986-9500, Email: [email protected]
Jim DeNike
Corixa Corporation
Phone: (206) 754-5716 , Email: [email protected]
SEATTLE, Washington -- A vaccine for leishmaniasis – a parasitic disease that
kills up to 500,000 adults and children every year – is one step closer to
reality. The Infectious Disease Research Institute (IDRI) today announced
receipt of a $15 million grant from the Bill & Melinda Gates Foundation to fund
their ongoing effort with Corixa Corporation (Nasdaq: CRXA) to develop a vaccine
to prevent leishmaniasis.
Leishmaniasis is a skin and visceral disease endemic in the Indian
sub-continent, Africa, South America, and the Middle East. According to the
World Health Organization (WHO), an estimated 15 million new cases of the
disease appear each year. Leishmaniasis is caused by the parasite leishmania,
which is carried by sand flies.
"We are excited to receive funding for our leishmaniasis program from the Bill &
Melinda Gates Foundation," stated Cynthia Healy, Ph.D., chair of the board of
IDRI. "This generous donation represents a serious commitment to treating and
preventing diseases of developing countries. IDRI and Corixa have been
collaborating on leishmaniasis research for the past several years, which has
resulted in a promising candidate vaccine. Support from the Bill & Melinda Gates
Foundation will allow us to optimize the vaccine and begin applying it in areas
of the world where it is needed most.
"IDRI's mission is to develop vaccines for diseases of developing countries, and
our collaboration with Corixa has been instrumental in these efforts. Our aim is
to produce the world's first successful vaccine against a parasitic disease."
Already in Phase I clinical trials in Brazil, IDRI has tested a prototype
leishmaniasis vaccine comprising Corixa's novel antigens on a compassionate-use
basis on a small number of leishmaniasis patients. The funding will allow IDRI
to pursue additional studies, including advanced clinical trials in several
countries. As part of the collaboration, Corixa anticipates the company will
manufacture and supply product formulations for further clinical studies. They
also will manage required, multi-site clinical trials and product registration
efforts. Corixa's adjuvant technology also is expected to be a key component of
the vaccine.
"Corixa's collaboration with IDRI brings complementary skills, resources and
technology together to attempt to resolve diseases that affect major patient
populations in less developed nations," said Steven Reed, Ph.D., chief
scientific officer and executive vice president of Corixa. "A vaccine powered by
both Corixa's antigens and adjuvants, combined with IDRI's efforts to conduct
vaccine testing in developing countries, will be a dramatic breakthrough for
this important unmet medical need."
Corixa has developed a prototype vaccine for leishmaniasis, which has been
tested in patients in Brazil. A similar vaccine has been licensed to Heska,
Inc., for vaccination of dogs against Leishmania infection. Dogs can serve as a
host for the sand fly that harbors the parasite responsible for the disease.
About IDRI
IDRI is a not-for-profit corporation dedicated to the study of infectious
diseases and cancer and to the development of vaccines, therapeutics and
diagnostics for their treatment and prevention. IDRI's mission is to promote
such research through its internal programs and, occasionally, by supporting
research at other organizations with expertise in infectious disease and cancer
research consistent with these purposes and with its tax exempt status under
Section 501(c)(3) of the Internal Revenue Code. IDRI research is supported by
the National Institutes of Health.
About Corixa
Corixa is a research- and development-based biotechnology company committed to
treating and preventing autoimmune diseases, cancer and infectious diseases by
understanding and directing the immune system. Corixa is focused on
immunotherapeutic products and has a broad technology platform enabling both
fully integrated vaccine design and the use of its separate, proprietary vaccine
components on a standalone basis. The company partners with numerous developers
and marketers of pharmaceuticals and diagnostic products with the goal of making
its potential products, Powered by Corixa, available to patients around the
world. Corixa was founded in 1994 and is headquartered in Seattle, Wash., with
additional operations in Hamilton, Mont. and Redwood City, Calif. For more
information, call the company's investor relations information line at
1-877-4CORIXA or 1.877.426.7492 or visit Corixa's website.
Forward-Looking Statements
Except for the historical information presented, certain matters discussed in
this press release are forward-looking statements that are subject to certain
risks and uncertainties that could cause actual results to differ materially
from any future results, performance or achievements expressed or implied by
such statements. Such risks and uncertainties include adverse events resulting
from further clinical trials of the leishmaniasis vaccine being developed by
IDRI and Corixa and other risks detailed from time to time in Corixa's public
disclosure filings with the U.S. Securities and Exchange Commission (SEC),
including the Annual Report on Form 10-K for the fiscal year ended December 31,
1999, and the Company's Registration Statement on Form S-3, filed on March 7,
2000. Copies of Corixa's public disclosure filings with the SEC are available
from its investor relations department.
###
The Bill & Melinda Gates Foundation is dedicated to improving people's lives by
sharing advances in health and learning with the global community. Led by Bill
Gates' father, William H. Gates, Sr., and Patty Stonesifer, the Seattle-based
foundation has an endowment of approximately $24 billion.
====================================================
77.) Report on the fourth TDR/IDRI meeting on second generation vaccine against
Leishmaniasis. Merida, Yucatan, Mexico, May 1-3, 2001.
====================================================
Source: www.uady.mx/~biomedic/biblio.htm REVISTA BIOMEDICA
Revista Biomedica, 2002 Vol_ 13 Num 1.htm
Eric Dumonteil1, Diane McMahon-Pratt2, Virginia L. Price3.
1Universidad Autónoma de Yucatán, Mérida, Yucatán, Mexico, 2Yale University
School of Medicine, New Haven, CT, USA, 3UNDP/ World Bank/WHO Special Programme
in Training and Research in Tropical Diseases (TDR) Geneva, Switzerland.
A meeting entitled "Second generation vaccines against leishmaniasis" was held
in Merida, Mexico on May 1-3, 2001. The meeting was hosted by the Universidad
Autónoma de Yucatán in Merida and sponsored by the WHO/World Bank/UNDP Special
Programme for Training and Research in Tropical Disease (TDR) and the Infectious
Disease Research Institute (IDRI). The meeting consisted of two parts: 1) a
review of the evaluation of recombinant Leishmania antigen testing in two
independent labs and 2) individual presentations regarding second generation
Leishmania vaccine candidates. [The first generation Leishmania vaccine is
considered to be the killed whole Leishmania parasite vaccine that has been
tested in clinical trials in Iran, Sudan, and Latin America (1-3). A new
formulation of this vaccine including bacillus Calmette-Guérin(BCG) and alum as
adjuvants will be tested in 2001 in Iran and Sudan]
In an effort to organize a systematic way of testing candidate antigens as
potential vaccine candidates, comparative studies were done in two different
laboratories; Universidade Federal de Bahia, Salvador, Brazil, and the
University of Copenhagen, Copenhagen, Denmark. Nine different antigens (plus
soluble Leishmania antigen as a positive control) were tested as vaccine
candidates in murine models for Leishmania. Adjuvants used were monophosphoryl
lipid (MPL, donated by Corixa corporation) and interleukin 12 (IL-12 , donated
by Genetics Institute). The results of these studies were, however, inconclusive
largely due to technical problems regarding the stability and potency of the
antigens. The need for guidelines concerning the characterization and testing of
recombinant antigens were discussed (see conclusions).
The individual presentations on second generation Leishmania vaccine candidates
suggested several promising candidates that have shown protection in animal
studies. Some of these presentations are summarized below.
Antigens that show protection in animal models
Nicolas Fasel of the University of Lausanne, Lausanne, Switzerland and Sima
Rafati of the Institute Pasteur in Tehran, Iran, described vaccination studies
against cutaneous Leishmania (L. major) done in mice and African green monkeys.
The antigen used was L. major histone H1, a nuclear antigen that has no homology
to human H1. Antigen was made either as a recombinant glutathione S-transferase
(GST)-fusion protein in E. coli or as a long synthetic peptide representing the
complete histone H1 sequence. Montanide ISA 721 was used as adjuvant. Elisa data
showed that both antigens elicited an increase in specific antibodies after
vaccination, some (but not all) monkeys had increase gamma interferon
(IFN-gamma) levels, and all exhibited a positive delayed type hypersensitivity
(DTH) response.
A DNA vaccine was also prepared encapsulated in microspheres, small particles of
poly-lactide-co-glycolide. DNA encoded antigens were histone H1, cysteine
proteinase B (CPB), and cysteine proteinase A (CPA), alone or in combination. A
single injection of 20 µg DNA was used for vaccination of mice. Only the
cocktail containing CPA and CPB showed protection.
J. Alexander (University of Strathclyde, Glasgow, Scotland) studied the vaccine
potential of enzymatically active and inactive CPB to protect against L.
mexicana, and showed that vaccination with CPB alone may stimulate interleukin 4
(IL-4) production and exacerbate infection. However, the addition of IL-12 to
these active and inactive CPB recombinant antigens resulted in significant
inhibition of lesion growth in CBA/Ca, BALB/c and C57BL/6 mice following
challenge infection. A DNA vaccine consisting of genes for the antigens CPB,
GP63 and GP46 has been tested in a murine model against L. mexicana by E.
Dumonteil of the Universidad Autónoma de Yucatán, Merida, Mexico. The individual
antigens showed limited protection, but a high dose (50 µg each) of the
combination of all three antigens showed strong protection in initial studies.
G. Grimaldi and R. Porrozzi (FIOCRUZ, Rio de Janeiro, Brazil) and A. Campos-Neto
(Infectious Disease Research Institute, Seattle, WA, USA) have examined rhesus
macaques (Macaca mulatta) as an experimental model for study of cutaneous
leishmaniases (CL) induced by either L. major, or L. amazonensis, or L.
braziliensis infection. The rhesus macaques as a model for human disease is
thought to be appropriate in that the outcome of Leishmania infection in
primates is similar to that in humans in that it largely depends on the
virulence of the infecting parasite strain and the immune responsiveness of the
host. Lesion development, histopathology of CL and the Th1-type profile are
similar to the human disease.
Several antigen/adjuvant combinations were tested for the induction of
protection in both mice and monkeys to Leishmania challenge. The L. major
antigens tested were: LeIF (ribosomal initiation factor), STI1 (a stress and
temperature inducible protein), and TSA (a thiol-specific antioxidant).
Mice were immunized with a di-fusion comprised of TSA-LmSTI1 and a tri-fusion
comprised of TSA-LmSTI1-LeIF. Protection was seen with either the di-fusion or
the tri-fusion with IL12 as adjuvant but not with several other adjuvants
tested.
Monkey immunizations were performed with TSA and LmSTI11 as antigens and IL-12
plus alum as the adjuvant. (Alum with IL-12 does not appear to change the Th1
pattern normally seen with IL-12 as adjuvant but seems to make the antigen more
immunogenic.) Three immunizations of 25 µg each antigen were given with a
challenge six weeks after the last immunization. Protective immunity followed
immunization, in that no lesions developed in any of vaccinated monkeys (n = 6)
after infection. (All controls developed lesions.) Monkeys vaccinated with
LmSTI1-TSA+IL-12+alum were also protected against rechallenge with L. major (4
months following the first challenge), but no cross-protection was found against
tertiary challenge 2 months following the second challenge with L. braziliensis.
The data point to a long-lasting anti-L. major immunity induced in primates by
the recombinant antigens LmSTI1 and TSA.
G. Matlashewski of McGill University (Montreal, Canada) described the A2 genes
of Leishmania, which encode proteins of unknown function. The A2 genes are part
of a multigene family of at least 11 genes and the protein is composed largely
of multiple repeats of a 10 amino acid sequence. The protein is abundant in
amastigotes and absent in promastigotes. It is present in L. infantum, L.
chagasi, L. mexicana, L. amazoniensis, and L. donovani but not in L. tropicana
and L. major. (L. major has been shown to have the A2 genes but in truncated
form.)
The role of the A2 proteins has been studied both by creating knock-out strains
(8 of the 11 genes were knocked out) and by using anti-sense technology. It was
then shown that the A2-deficient strains of L. donovani were avirulent in mice.
Thus, A2 can be considered an amastigote specific virulence factor and therefore
a good vaccine candidate for L. donovani.
A2 was tested as a vaccine (recombinant protein or DNA vaccine) in a murine
model of visceral leishmaniasis. Mice vaccinated with A2 protein showed greatly
reduced parasite numbers in the spleen and a mixed Th1/Th2 type of response
(increased IFN-gamma by spleen cells and no increase of IL4 but increased IgG2a
and IgG1 levels). A2 as a DNA vaccine gave partial protection (measured by
reduced LDU).
C.B. Palatnik de Sousa (University of Rio de Janeiro, Rio de Janeiro, Brazil)
studied the fucose mannose ligand (FML) antigen complex of L. donovani and its
GP36 component as a vaccine.
After demonstrating the protective capacity of FML and GP36 with saponins as
adjuvant in mice, a dog vaccination trial was initiated (4). The FML-vaccine was
examined in dogs naturally exposed in an endemic area in Natal, Brazil.
Ninety-seven percent of the vaccinated dogs produced antibodies and 100%
demonstrated a DTH response to the FML antigen seven months post-vaccination.
After 2 years of monitoring the dogs, data indicate that significant protection
was achieved: only 8% of vaccinated dogs showed mild signs of visceral
leishmaniasis, with no deaths, while in the control group 33% of the dogs
developed clinical symptoms or fatal disease. After 41 months, 3/4 of the
control dogs were infected (as determined by PCR and bone marrow puncture) and
the remaining vaccinated dogs were all negative for parasites and continued to
maintain positive antibody and DTH responses. Thus, the FML-vaccine induced
significant protection against canine visceral leishmaniasis in the field.
D. Smith (Imperial College, London, UK) described the hydrophilic acylated
surface antigens (HASPs) as vaccine candidates. HASPs are dually acetylated at
their N-termini, a modification required for subcellular targeting within the
parasite to the membrane. Although the precise function(s) of these proteins are
not known, genetic experiments using knock-out and over-expression mutants
clearly indicate a role in virulence of L. major. Although all of the proteins
family members are expressed in metacyclic promastigotes, only HASPA1 and B are
detectable in amastigotes.
HASPs, expressed as unmodified recombinant proteins in E.coli, were employed for
immunization of BALB/c mice (with or without IL-12). Immunization resulted in
protection against infection with L. donovani in the animal model of visceral
leishmaniasis (5). HASPB1 induces a low level of IL-12 production in murine
dendritic cells. Protection correlates with the level of IFN-gamma producing CD8
T cells and IgG1 production. Interestingly, rHASPB1 fails to confer protection
in IL-4 and IL-4 receptor alpha (IL-4R) deficient mice. These data suggest
further complexity in the regulation of vaccine-induced immunity.
Understanding mechanisms of protection
P. Scott of the University of Pennsylvania (Philadelphia, PA, USA) discussed
studies on the mechanism of protection from leishmaniasis which were done in a
Vervet monkey model (6). The antigen used was ALM (autoclaved L. major) with
IL-12 as adjuvant. The immunizations resulted in increased specific IFN-gamma
levels and a typical Th1-type response. Specific IFN-gamma levels were as high
as the positive controls, which were animals that had already healed and were
resistant. However, the vaccine did not protect. The conclusion from this study
was that IFN-gamma production by PBLs to crude leishmanial antigen does not
always correlate with immunity.
He then discussed the role of IL-12 as one of several parameters that might be
required for eliciting and maintaining immunity (7). It was shown that IL-12
knockout mice, if treated with IL-12 exogenously, are resistant to L. major
infection. However, upon rechallenge after cessation of IL-12 treatment, they
became susceptible. In addition, adoptive transfer of Th1 cells from healed mice
into IL-12 knockout mice failed to protect against challenge. Moreover, the
IFN-gamma response is not recovered in the IL-12 knockout mice. Thus, IL-12
seems to be needed continuously to maintain resistance. This might be due to a
requirement for IL-12 to optimize IFN-gamma production from Th1 cells, to
protect Th1 cells from apoptosis, to promote Th1 cells survival, and/or to
recruit additional Th1 cells from a naïve or undifferentiated T cell population.
D. McMahon-Pratt (Yale University, New Haven, CT, USA) discussed severity of
disease as a function of the infecting Leishmania species together with host
genetics and consequent inflammatory and immune responses. In the case of
cutaneous murine leishmaniasis, infection caused by L. amazonensis appears to be
readily distinguished from that induced by L. major in a number of significant
immunologic features. For L. amazonensis, the mechanisms involved in
pathogenesis in the murine model appear to singularly involve immune subversion
and require the participation of both CD4+ T cells and B cells (immunoglobulin).
A low level of IFN-gamma (with little/no IL-4) production seems to be a feature
of disease. Antigen presentation and monocyte recruitment at the local site of
infection appears to be critical for the development of pathology. The roles of
immune T and B cells in pathology as well as resolution of disease could impact
the efficacy of vaccines against New World leishmaniasis, especially potentially
as the immune response wanes after vaccination.
A. Campos-Neto (Infectious Disease Research Institute, Seattle, WA, USA),
pointed out that for the past 20 years, it has been generally accepted that
immunity against experimental infection of mice with Leishmania is strictly
dependent of the generation of a Th1 type of immune response against the
parasite's antigens. However, they have observed that several leishmanial
recombinant antigens, selected on this criteria and expressed as recombinant
proteins, do not necessarily turn out to be protective antigens. For example,
BALB/c mice infected with L. major develop low antibody titers to the antigen
Ldp23, and to many others tested. In addition, Ldp23 induces preferentially Th1
response in lymph node cells from infected mice. However, in combination with
adjuvants that preferentially induce Th1 responses such as IL-12 and MPL-SE,
despite stimulating strong antigen specific Th1 response in the absence of any
detectable Th2 response, Ldp23 does not confer protection. In contrast, the
antigen LACK stimulates strong and preferentially Th2 responses in lymph node
and spleen cells from L. major-infected mice. In addition the sera of these
animals contain high titers of IgG1 anti-LACK antibodies. In spite of this, LACK
induces substantial protection in BALB/c mice if administered in conjunction
with adjuvants that stimulate Th1 responses. In another situation, antigens like
LmSTI1 stimulate strong and preferentially Th1 responses in lymph node cells of
BALB/c mice infected with L. major and the sera of these animals contain high
titers of both IgG1 and IgG2a anti-LmSTI1 antibodies. Moreover, LmSTI1 induces
excellent protection in these animals if used with IL-12 or MPL-SE as adjuvants.
Therefore, for antigen selection purposes in vaccine development against
leishmaniasis these results do not support the Th1 paradigm, although a Th1
response may well be essential for protection against leishmaniasis. In
conclusion, for vaccine development against leishmaniasis, the polarization to
Th1/Th2 antigen-specific immune response that is developed against the parasite
antigens during the infectious process may be irrelevant. Rather, immunogenicity
and perhaps the amount of antigen expressed or secreted by the parasite in vivo,
are more important factors reflecting protective anti parasite immune response.
Antigens that fulfill these criteria should therefore be more successful in
inducing protection as long as they are administered with adjuvants that in
combination with them modulated a strong Th1 response.
M. Barral-Neto (Universidade Federal de Bahia, Bahia, Brazil) described a
priming in-vitro (PIV) system that was used to evaluate the immune response of
naïve individuals following in-vivo vaccination with parasite. IFN-gamma levels
were followed as an indicator of the type of response to Leishmania antigen.
Peripheral blood mononuclear cells (PBMC) of volunteers who were DTH-negative
and anti-Leishmania antibody-negative were used for in-vitro stimulation with
Leishmania antigen and IFN-gamma was monitored. This in-vitro stimulation
experiment identified two different types of responders: those that produced low
amounts of IFN-gamma and those that produced high levels of IFN-gamma. The
IFN-gamma levels were directly proportional to tumor necrosis factor- alpha
(TNF-alpha) and interleukin-10 (IL-10) levels but not to interleukin-5 (IL-5)
levels. Those volunteers who produced low amounts of IFN-gamma in vitro remained
low producers 40 days after vaccination, whereas high producers exhibited
increased IFN-gamma production after vaccination. However, at 6 months
post-vaccination, all individuals tested were producing similarly high levels of
IFN-gamma upon stimulation of their PBMC with Leishmania promastigotes,
indicating that the low in-vitro producers were slow in-vivo responders to
vaccination. High IFN-gamma producers exhibited an increased frequency of
activated CD8+T cells both in-vitro and in-vivo, as compared to low IFN-gamma
producers. This delay in the cell mediated immune (CMI) response may influence
resistance to leishmaniases.
New antigen discovery
T. Aebischer, from the Max Plank Institute in Tubingen, Germany, discussed the
generic characteristics of potential new protective antigens. Previous work (4)
indicated that protective antigens require a minimal level of expression of
105-6 molecules per organism throughout the parasite lifecycle. In addition,
protection seemed to be dependent upon antigen accessibility, i.e. a molecule
expressed on the surface membrane or secreted.
Studies of the kinetics of antigen presentation in infected mice, examined using
green fluorescent protein (GFP)-labeled parasites, confirm these observations.
They have found two waves of antigen presenting cells in high dose infection in
the draining lymph node with only the second harboring live parasites.
Therefore, in natural low dose infection protective antigens presented from live
parasites should be accessible throughout infection and thus would most likely
be secreted or surface components. These results strengthen the conclusion that
in the rational search for candidate vaccine antigens, they should be abundant,
preferably secreted or surface exposed protein molecules.
J. Blackwell (Wellcome Trust Centre for Molecular Mechanisms in Disease,
Cambridge, UK) described a microarray analysis of the Leishmania life cycle as a
mechanism for identifying new potential vaccine antigens. In the vertebrate
host, metacyclic promastigotes rapidly enter macrophages and transform to
amastigote forms. They used DNA microarrays for simultaneous monitoring of
expression profiles for 2183 unique Leishmania genes as the parasite undergoes
the developmental transition from logarithmic promastigotes to metacyclic forms
and host-derived amastigotes. From this analysis they have identified over 100
previously unknown genes which are upregulated in amastigotes. These are
presently being tested as new vaccine candidates. Some cocktails of these
antigens appear to be effective as DNA vaccines in mice.
Conclusions.
Based on these presentations, it was concluded that several promising Leishmania
vaccine candidates exist that warrant further development, eventually towards
human clinical testing. However, it was recommended that strict quality control
of recombinant antigens should be included in pivotal animal studies (as well as
for monkey and human trials). Antigen characterization should include: SDS-PAGE
(reduced and non-reduced), Western blot analysis, endotoxin levels, sterility
and amino acid analysis for determination of protein concentration. It was
agreed that the minimum criteria for moving a candidate vaccine to phase I
studies must include the consistent (i.e. repeated in a second independent
laboratory) induction of significant protection in an animal model, and a
formulation with an adjuvant than can currently be used in clinical trials. It
was felt that collaboration and coordination of efforts in the testing of
vaccine candidate antigens in more than one laboratory is warranted.
Additionally, though there have been important development in this field, we
still do not understand completely what constitutes a protective response in
humans. It is thus considered important to encourage continued effort towards
understanding what constitutes long-term protection to leishmaniases both in
animal models as well as in humans. Defining the correlates of protection and
development of predictive assays for the evaluation of vaccine candidates are
important to the progress of the field.
References.
1.- Sharifi I, FeKri A R, Aflatonian M R, Khamesipour A, Nadim A, Ahmadi-Mousavi
M R, et al Randomised vaccine trial of single dose of killed Leishmania major
plus BCG against anthroponotic cutaneous leishmaniases in Bam, Iran. Lancet
1998; 351: 1540-3.
2. Modabber F. First generation leishmaniases vaccines in clinical development:
Moving, but what next? Curr Opin Anti-infect Invest Drugs 2000; 2: 35-9.
3.- Velez I D, del Pilar Agudelo S, Arbelaez M P, Gilchrist K, Robledo S M,
Puerta J A, et al. Safety and immunogenicity of a killed Leishmania (L.)
amazonensis vaccine against cutaneous leishmaniasis in Colombia: a randomized
controlled trial. Trans R Soc Trop Med Hyg 2000; 94: 698-703.
4.- da Silva VO, Borja-Cabrera G P, Correia Pontes N N, de Souza E P, Luz K G,
Palatnik M, et al. A phase III trial of efficacy of the FML-vaccine against
canine kala-azar in an endemic area of Brazil (Sao Goncalo do Amaranto, RN).
Vaccine 2000; 19: 1082-92.
5.- Stager S, Smith D F, Kaye PM. Immunization with a recombinant
stage-regulated surface protein from Leishmania donovani induces protection
against visceral leishmaniasis. J Immunol 2000; 165: 7064-71.
6.- Gicheru M M, Olobo J O, Anjili C O, Orago A S, Modabber F, Scott P. Vervet
monkeys vaccinated with killed Leishmania major parasites and IL-12 develop a
type 1 response, but are not protected against challenge infection. Infect Immun
2001; 69: 245-51.
7.- Park A Y, Hondowicz B D, Scott P. IL-12 is required to maintain a Th1
response during Leishmania major infection. J Immunol 2000; 165: 896-902.
8.- Aebischer T, Wolfram M, Patzer S I, Ilg T, Wiese M, Overath P. Subunit
vaccination of mice against new world cutaneous leishmaniasis: comparison of
three proteins expressed in amastigotes and six adjuvants. Infect Immun 2000;
68:1328-36.
El artículo completo en formato PDF Rev Biomed 2002; 13:53-58
Corresponding address: Eric Dumonteil, Ph.D. Laboratorio de Parasitología,
Centro de Investigaciones Regionales, Universidad Autónoma de Yucatán, Ave.
Itzaes # 490 x 59, C.P. 97000, Mérida, Yucatán, Mexico. Tel/Fax: (52-9)
924-59-10 Email: [email protected]
Received October 18, 2001. Acepted December 19, 2001.
====================================================
78.) Drug development: LEISHMANIASIS
====================================================
Source: The WHO 1999 -2.000
Miltefosine promises to be the first oral treatment for visceral leishmaniasis.
Dose-finding and efficacy confirmation trials have been completed and the drug
will shortly be submitted for registration.
Miltefosine
Miltefosine, an anticancer drug that TDR and ASTA Medica (now Zentaris) have
been developing for visceral leishmaniasis, could be the first oral treatment to
become available for this disease (see TDR Programme Report, 1997-1998). During
the biennium, Phase II (dose-finding) and Phase III (efficacy confirmation)
trials in adult patients were successfully completed. In mid-2001, the drug will
be submitted for registration in India and Germany for use in patients aged over
12 years. As well, a Phase II trial in children was completed, and a Phase III
trial in children has begun (expected to finish end of October 2001), an
indication which could later be added to the criteria for use. A Phase IV (post
registration, in a real field situation) trial has been planned for India, Nepal
and Bangladesh, which will feed into the control programme. This Phase IV trial
will be supported by the WHO Regional Office for South-East Asia and the
Government of India.
====================================================
79.) Vaccines for cutaneous leishmaniasis
====================================================
Source: The WHO 1997-1998
A number of first-generation vaccines[i] have produced encouraging results when
used in single dose in Phase III field trials[i]. They are now being tested in
two and three doses against cutaneous leishmaniasis in Iran, in Ecuador (outside
TDR), Colombia, Brazil (outside TDR) and Venezuela.
Iran
Results from a vaccine trial in Bam, using a single dose of killed Leishmania
major promastigotes[i] + BCG[i], show that boys were protected more than girls
and that BCG alone may have a short-lived protective effect. After two years,
78% protection was seen in boys who had received the vaccine.
In a trial in Isfahan, only 35% of children people given a single-dose vaccine
of killed L. major promastigotes + BCG, responded to the vaccine. The incidence
of disease was 35% lower in those who responded to the vaccine compared to those
who did not respond.
Ecuador (outside TDR)
Over 70% protection against cutaneous leishmaniasis was recorded during the
first year of a small-scale vaccine trial. The vaccine was given in two doses,
and consisted of whole killed Leishmania promastigotes native to the New World
plus BCG. An ongoing study will determine how long this protective immunity will
last.
A placebo-controlled trial is being conducted using a vaccine of whole killed
promastigotes from L. amazonensis + BCG.
Colombia
Phase II trials have compared two vaccines consisting of L. amazonensis with and
without BCG. Plans for Phase III trials will involve only the preparation
without BCG.
Other trials
Phase II trials in Brazil (outside TDR) have shown that a preparation of
merthiolate L. amazonensis without BCG is immunogenic.
A trial in Venezuela of a killed L. mexicana + BCG vaccine for cutaneous
leishmaniasis, is being guided, but not funded by TDR.
====================================================
80.) Vaccine development: LEISHMANIASIS
====================================================
Source: The WHO
Results of the first trial of a vaccine against visceral leishmaniasis showed it
to be associated with a lower incidence of disease
Sudan: leishmaniasis vaccine trial The first trial of a vaccine against visceral
leishmaniasis in humans was completed.[8] The trial was conducted by scientists
of the Institute of Endemic Diseases, University of Khartoum, Sudan, supported
by TDR and assisted by Médecins sans Frontières-Holland, using a vaccine
composed of autoclaved Leishmania major promastigotes (Fesharki et al, at Razi
Vaccine and Serum Institute, Iran) mixed with a low dose of bacillus
Calmette-Guérin (BCG) (as adjuvant), which was compared with BCG alone. The
presence of extensive cross-reactivity between different species of Leishmania
was the rationale behind this trial of a vaccine, made from L. major, which had
proved almost 100% effective in langur monkeys against L. donovani infection.[9]
The trial was carried out in the Sudan where visceral leishmaniasis is a major
cause of morbidity and mortality (a prevalence of 80-130 per 1000 in the study
area). Here, as in many other endemic countries, the development of a safe,
effective and cheap vaccine would be a long-term solution for controlling
visceral leishmaniasis. Drug treatment does exist, but is prohibitively
expensive, not easy to administer, not always available, and resistance to it
develops rapidly. Vector control is also a possibility, but requires
infrastructure that is not available.
In the double-blind study, no evidence was found that two injections of
Leishmania + BCG offered significant protective immunity against visceral
leishmaniasis compared with BCG alone. However, the Leishmania + BCG vaccine did
induce significantly higher rates of leishmanin skin test (LST) conversion (30%,
vs. 7% by BCG alone) at 42 days, which was associated with a significantly lower
incidence of disease – responders had a 43% lower incidence of leishmaniasis as
compared to LST non-responders (7.2% vs. 12.7%, p<.003). Similar results, i.e.
lower incidence of disease in LST converted than non-converted individuals, have
been obtained in other studies. As BCG alone might have some protective activity
against leishmaniasis, as seen in the therapeutic trials of Convit et al in
Venezuela, the real prophylactic effect of the vaccine, compared to no vaccine
(and not to BCG as in this trial), might be higher. In this trial, BCG was used
for ease of keeping the trial blind.
To improve the immunogenicity of killed Leishmania vaccines, different adjuvants
used in humans are being sought. Safety and efficacy trials of alum-precipitated
Leishmania + BCG have begun in the Sudan. Preliminary results showed that a
single injection produces a dramatic immune response – a strong LST conversion –
in every recipient (better than three injections without alum). Multiple doses
of L. major + BCG vaccine did not prove to be more effective than a single
injection in preventing cutaneous leishmaniasis, so development of this vaccine
is not being pursued without the addition of alum. Following a successful
comparative safety and immunogenicity trial of different formulations of
Mayrink’s vaccine (killed L. amazonensis, produced by Biobras, Brazil), with or
without adjuvant,[10] a trial of three injections without adjuvant has begun in
Colombia (Velez ID, Universidad de Antioquia, Medellin).
A dozen or so recombinant antigens were recently evaluated as potential second
generation vaccine candidates in independent testing coordinated by TDR and
conducted in two laboratories in Brazil and Denmark. Unfortunately the results
were inconclusive, as not all the control preparations were active. Several
second generation vaccines (synthetic peptides and multi-fusion recombinant
proteins) are being developed outside TDR, and efforts are being made to create
a collaborative programme for these activities, ideally through a consortium
which will coordinate the definition, testing and advanced development of
promising candidate antigens.
[8] Khalil EA et al. Autoclaved Leishmania major vaccine for prevention of
visceral leishmaniasis: a randomised, double-blind, BCG-controlled trial in
Sudan. Lancet, 2000, 356(9241):1565-9. [PMID: 11075771 [PubMed - indexed for
MEDLINE]]
[9] Misra A, Dube et al. Successful vaccination against Leishmania donovani
infection in Indian langur using
alum-precipitated autoclaved Leishmania major with BCG. Vaccine, 2001,
19(25-26):3485-92. [PMID: 11348715 [PubMed - indexed for MEDLINE]]
[10] Velez ID et al. Safety and immunogenicity of a killed Leishmania (L.)
amazonensis vaccine against cutaneous leishmaniasis in Colombia: a randomized
controlled trial. Transactions of the Royal Society of Tropical Medicine and
Hygiene, 2000, 94: 698-703. [PMID: 11198661 [PubMed - indexed for MEDLINE]]
====================================================
81.) Vaccine from fly spit
====================================================
Fly saliva could protect us from a dangerous disease.
7 August 2001
JOHN WHITFIELD
Source: www.nature.com/
Worth spit: a new vaccine works against the fly that carries Leishmania.
© SPL
An injection of fly spit sounds like medieval quackery, but could be the
vanguard of modern medicine. Researchers have used sand fly saliva to develop a
vaccine that protects mice against leishmaniasis, a disease spread by the
insect1.
This, the first potential vaccine against an insect-borne disease derived from
the carrier, rather than the parasite itself, is based on chemicals that help
the fly feed, preventing blood clotting and dilating blood vessels.
Leishmania, a single-celled protozoon, infects about 12 million people
worldwide. Different types of leishmaniasis erode the mucus membranes of the
mouth, nose and throat, or internal organs. This latter condition is often
fatal.
Jose Ribeiro, of the US National Institute of Allergy and Infectious Diseases
(NIAID) in Bethesda, Maryland, focused on the skin-attacking Leishmania major,
which is spread by the Middle Eastern sand fly (Phlebotomus papatasi).
The bites of uninfected sand flies seem to protect mice from Leishmania, the
group had previously found. Apparently, the same thing applies to people in
South America, Africa and around the Mediterranean, where the disease is common.
"Newcomers and children get sick, but they're the tip of the iceberg of those
who are infected," says Ribeiro.
Ribeiro's team isolated a protein from the fly's saliva that provoked a
particularly strong mouse immune response to Leishmania. They identified the
gene for this protein, and injected it into mice. The mouse's cells made the
protein from the DNA, triggering their immune response.
When subsequently injected with a mixture of fly saliva and Leishmania, the mice
developed none of the disease symptoms. They did not eliminate the parasite, but
suppressed it to one-hundredth of the level found in untreated mice. This is
similar to the response of humans who are 'immunized' by fly bites, says
Ribeiro.
"This is a very promising vaccine candidate," says immunologist Heidrun Moll of
the University of Wurzburg, Germany. The importance of the carrier in the immune
response to insect-borne disease is widely acknowledged, says Moll, but
technical difficulties - such as breeding the insects and keeping them contained
- has slowed progress along this avenue.
About half a dozen potential leishmaniasis vaccines have been derived from the
parasite over the past decade, including one by Moll herself. Eventually, people
could be immunized using a cocktail of vaccines against both fly and parasite,
she says.
As well as different vaccines for different Leishmania species, we may also need
vaccines based on different species of sand fly - salivary proteins vary a great
deal between species, says Ribeiro. "But this is not a big deal," he assures -
it takes less than two months to go from fly spit to vaccine candidate.
Researchers are also targeting the insects that carry other vaccines. One
possible way to fight malaria is to develop vaccines that "do harm" to mosquitos
that suck them up in human blood, says Filip Dubovsky of the Malaria Vaccine
Initiative in Washington DC. As yet, there are no candidate malaria vaccines
that exploit mosquito saliva.
References
Valenzuela, J. G. et al. Towards a defined anti-Leishmania vaccine targeting
vector antigens: characterization of a protective salivary protein. Journal of
Experimental Medicine, 194, 1 - 13, (2001).
====================================================
82.)Toward a defined anti-Leishmania vaccine targeting vector antigens:
characterization of a protective salivary protein.
====================================================
J Exp Med. 2001 Aug 6;194(3):F7-F9.
Valenzuela JG, Belkaid Y, Garfield MK, Mendez S, Kamhawi S, Rowton ED, Sacks DL,
Ribeiro JM.
Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious
Diseases, National Institutes of Health, 4 Center Dr., Rm. 4/126, Bethesda, MD
20892, USA.
Leishmania parasites are transmitted to their vertebrate hosts by infected
phlebotomine sand fly bites. Sand fly saliva is known to enhance Leishmania
infection, while immunity to the saliva protects against infection as determined
by coinoculation of parasites with vector salivary gland homogenates (SGHs) or
by infected sand fly bites (Kamhawi, S., Y. Belkaid, G. Modi, E. Rowton, and D.
Sacks. 2000. Science. 290:1351-1354). We have now characterized nine salivary
proteins of Phlebotomus papatasi, the vector of Leishmania major. One of these
salivary proteins, extracted from SDS gels and having an apparent mol wt of 15
kD, was able to protect vaccinated mice challenged with parasites plus SGH. A
DNA vaccine containing the cDNA for the predominant 15-kD protein (named SP15)
provided this same protection. Protection lasted at least 3 mo after
immunization. The vaccine produced both intense humoral and delayed-type
hypersensitivity (DTH) reactions. B cell-deficient mice immunized with the SP15
plasmid vaccine successfully controlled Leishmania infection when injected with
Leishmania plus SGH. These results indicate that DTH response against saliva
provides most or all of the protective effects of this vaccine and that salivary
gland proteins or their cDNAs are viable vaccine targets against leishmaniasis.
====================================================
83.) Otros estudios y referencias Bibliograficas
====================================================
Source; The net
1, CHARACTERIZATION OF SECRETED/SHED LEISHMANIA ANTIGENS FOR USE IN SUB-UNIT
VACCINE AND DIAGNOSTIC DEVELOPMENT, Brannon M., U.S.A.
2, COMPARATIVE STUDY OF CELLULAR RESPONSES AFTER STIMULATION OF HUMAN T
LYMPHOCYTES BY DEFINED RECOMBINANT LEISHMANIAL ANTIGENS, Meddeb-Garnaoui A.,
TUNISIA
3, CHARACTERIZATION OF HEALTHY DONORS AND CL PATIENTS' T CELL RESPONSES TO
LEISHMANIAL ANTIGENS, Turgay N., TURKEY
4, THE EFFICACY OF IMMUNIZATION WITH MIXED LIVE/KILLED LEISHMANIA MAJOR
PROMASTIGOTES, Marufov A., UZBEKISTAN
5, MULTIPLE DOSES OF AUTOCLAVED LEISHMANIA MAJOR VACCINE AGAINST ANTHROPONOTIC
CUTANEOUS LEISHMANIASIS IN BAM, IRAN, Sharifi I., IRAN
6, PROTECTIVE EFFICACY OF MULTIPLE DOSES OF A LEISHMANIA MAJOR VACCINE MIXED
WITH BCG IN ZOONOTIC CUTANEOUS LEISHMANIASIS (ZCL) ENDEMIC AREA, Khamesipour A.,
IRAN
7, IMMUNE RESPONSES MEASURED IN HUMAN VOLUNTEERS VACCINATED WITH AUTOCLAVED
LEISHMANIA MAJOR PLUS BCG, Mahmoodi M., IRAN
8, THE ROLE OF BCG IN IMMUNE RESPONSES INDUCED BY MULTIPLE DOSES OF AUTOCLAVED
LEISHMANIA MAJOR VACCINE INJECTION, Alimohammadian M.H., IRAN
9, PHASE III EFFICACY FIELD TRIAL OF MULTIPLE DOSES OF AUTOCLAVED LEISHMANIA
MAJOR VACCINE MIXED WITH BCG IN CHILDREN IN ZOONOTIC CUTANEOUS LEISHMANIASIS
(ZLC) ENDEMIC AREA , Khamesipour A., IRAN
10, DEDTRITIC CELL VACCINATION AGAINST EXPERIMENTAL CUTANEOUS LEISHMANIOSIS,
Dotsika E., GREECE
11, DNA VACCINATION AGAINST LEISHMANIA MAJOR IN THE MURINE MODEL WITH DIFFERENT
CANDIDATE, Bahloul C., TUNISIA
12, PROCYCLIC PROMASTIGOTES OF LEISHMANIA MAJOR CONFER MORE EFFICIENT IMMUNITY
THAN METACYCLIC ONE IN BALB/C MICE, Alimohammadian M.H., IRAN
13, INDUCING CELL MEDIATED IMMUNITY IN BALB/C MICE USING LIPOSOMES ENCAPSULATED
WITH CRUDE LEISHMANIA ANTIGENS (CLA), Jaafari M.R., IRAN
14, ORAL IMMUNIZATION(BALB/C MICE): A NEW STRATEGY FOR PROTECTION AGAINST
LEISHMANIASIS, Rossi-Bergmann B., BRAZIL
15, BCG, IL12 AND SAPONIN IN THE FML-VACCINE AGAINST VISCERAL LEISHMANIASIS IN
MICE, Palatnik-De-Sou.S.A. C.B., BRAZIL
16, T-SUPPRESSIVE COMPONENTS IN L. AMAZONENSIS, Rossi-Bergmann B., BRAZIL
17, COMPARISON BETWEEN THREE VACCINES AGAINST CANINE LEISHMANIASIS: IN VITRO
EVALUATION OF MACROPHAGE KILLING ABILITY, Trotta T., ITALY
18.) Identification and characterization of T cell-stimulating antigens from
Leishmania by CD4 T cell expression cloning
2001
Probst P, Stromberg E, Ghalib HW, Mozel M, Badaro R, Reed SG, and Webb JR
Journal of Immunology
166/498-505
19.) Leishmaniasis vaccination: Targeting the source of infection
2001
Reed SG
Journal of Experimental Medicine
194/F7-F9
20.) Potent stimulation of the innate immune system by a Leishmania brasiliensis
recombinant protein
2001
Borges MM, Campos-Neto A, Sleath P, Grabstein KH, Morrisey PJ, Skeiky YAW, and
Reed SG
Infection and Immunity
69/5270-5277
21.) Protection against cutaneous leishmaniasis induced by recombinant antigens
in murine and nonhuman primate models of the human disease
2001
Campos-Neto A, Porrozzi R, Greeson K, Coler RN, Webb JR, Seiky YAW, Reed SG, and
Grimaldi G.
Infection and Immunity
69/4103-4108
22.) A novel protein K26 of L. chagasi in combination with K39 upgrading the
sensitivity of the serodiagnosis of Visceral Leishmaniasis
2000
Badaro R, Nakatani M, Houghton R, Skeiky Y, Bhatia A, Ghalib H, Brites C, and
Reed S
Clin. Infect. Disease
31/293
23.) Canine visceral leishmaniasis on Margarita Island Nueva Esparta, Venezuela)
2000
Zerpa, O, Ulrich, M, Negron, E, Rodriguez, N, Centeno, M, Rodriguez, V, Barrios,
RM, Belizario, D, Reed, S, and Convit, J
Transactions of the Royal Society of Tropical Medicine and Hygiene
94/484-487
24.) Characterization of secreted/shed antigens of Leishmania for the
development of recombinant antigen based sub-unit vaccine and diagnostic
cocktails
1999
Skeiky YAW, Bhatia A, Daifalla NS, Jen S, Benson DB, Badaro R, Campos-Neto A,
Houghton RL, and Reed SG
American Journal of Tropical Medicine and Hygiene
61/266
25.) Cloning, characterization and serological evaluation of K9 and K26: two
related hydrophilic antigens of Leishmania chagasi
1999
Bhatia, A, Daifalla, NS, Jen, S, Badaro, R, Reed, SG, and Skeiky, YA
Mol. Biochem. Parasitol.
102/249-261
26.) A cloned antigen (recombinant K39) of Leishmania chagasi diagnostic for
visceral leishmaniasis in human immunodeficiency virus type 1 patients and a
prognostic indicator for monitoring patients undergoing drug therapy
1998
Houghton, RL, Petrescu, M, Benson, DR, Skeiky, YA, Scalone, A, Badaro, R, Reed,
SG, and Gradoni, L
Journal of Infectious Disease
177/1339-1344
27.) Human and murine immune responses to a novel Leishmania major recombinant
protein encoded by members of a multicopy gene family
1998
Webb, JR, CamposNeto, A, Ovendale, PJ, Martin, TI, Stromberg, EJ, Badaro, R, and
Reed, S
Infection and Immunity
66/3279-3289
VERY SOON !!!
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DATA-MEDICOS/DERMAGIC-EXPRESS No 5-(118) 28/02/2.003 DR. JOSE LAPENTA
R.
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Produced by Dr. Jose Lapenta R. Dermatologist
Maracay Estado Aragua Venezuela 2.003
-2026
Telf.: 04142976087 -
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