3/16/99
Microbiology II
Board Exam Extra Information
· Immunity--
· Active and passive/natural and artificial
· Active reacts to antigen
· Diphtheria and tetanus are both artificial passive and active natural
· Active natural—recovery from the disease—polio, diphtheria
· Immunoglobulins
· Ig
· 5 types
· A,G,D,E,M
· IgG—most abundant kind of Ig in the human system; have 4 subtypes (1-4); antitoxin; ab against common antigen; classical protective ab; fight the invading ag w/help from complement; destroy the ag or invader; diagnostic role—immunodiagnosis; placental crossing—immunity to fetus; monomeric only
· IgA—3 types
· Monomeric serum
· Dimeric serum
· Dimeric secretory
· In the serum they play an unclear role—toxin neutralization; similar to IgG, skin sensitizing ab
· Dimeric—2 ab molecules are joined together by a common protein (J chain)
· Secreted in body cavities, outside—copro-antibodies
· Mother's milk, saliva, GI excretion, perspiration
· Colostrum
· Protect animal by neutralizing ag
· Any defect in IgA secretory synthesis respiratory aliment
· IgM--pentameric
· 5 units joined together w/J chain
· each molecule has ag binding sites—makes 10 ag binding sites, but only 5 are active
· abundant on B cells
· might be involved in ag recognition
· 1st ab to appear after immunization
· highly bactericidal
· cold hemagglutination test—Mycoplasma pneumoniae (walking pneumonia); dependent of IgM produced in the system in response to the bacteria; precipitate at 2°C not at 20°C
· IgD
· Lowest in amount
· Last of 5 groups to be ID
· Shortest lived
· Present on B cells abundantly
· Implicated more in ag recognition
· IgE
· Reagenic ab
· Low in amount
· Higher than IgD
· In atopic person, person suffering from various allergic reactions (atopes), hypersensitive reactions
· PK ab—prauswitz and Kustner—scratch test--immunogens