How the virus works

 

 

War on HIV How the virus works and how our knowledge helps us combat HIV.
Below you will find illustrations on how HIV attacks cells and how medications work.
War 1 The CD4+ cell (sometimes called a T-helper cell) is a white blood cell that is a part of our immune system, which helps us fight infection.
War 2 HIV attacks these cells and turns them into HIV factors. As HIV copies are manufactured, the CD4+ cells are effectively destroyed over time.
War 3 Once inside the CD4+ cell, the HIV's single strand RNA (red coil) uses an enzyme (e) known as "reverse transcriptase" to convert HIV RNA into double strand DNA.
war4 The HIV DNA (red-blue double coil) moves into the nucleus of the CD4+ cell, where it becomes part of the CD4+ cell's own DNA.
War 5 Once HIV DNA is in the nucleus, it takes over the CD4+ cell and instructs the cell to produce more HIV virus, which are sent out to infect more CD4+ cells.
War 6a HIV attacks both activated CD4+ cells which have been "turned on" and are dividing and actively fighting infection . . .
War6b . . . and resting CD4+ cells which have not encountered any infection and are waiting to be called into action.
War7aWar7b While both activated and resting CD4+ cells are attacked by the HIV, activated cells reproduce the virus faster and in greater amounts.
War 8 Drugs know as "nucleoside analogues" (NA) bind the RNA of the HIV virus and interfere with the DNA building process. The virus begins to produce its DNA, but the viral DNA is incomplete and unable to make new copies of the viruses.
War9 Some nucleoside analogue drugs such as Zerit (stavudine, d4T) and Retrovir (zidovudine, AZT) are known as thymidine analogues. Thymidine analogues (NA) are more effective in activated CD4+ cells.
War10 Non-Thymidine nucleoside analogues (NA) such as Videx (didanosine, ddI), Hivid (zalcitabine, ddC), and Epivir (Lamivudine, 3TC) are more effective in resting CD4+ cells.
war11 Another class of antiretroviral agents is called " non-nucleoside reverse transcriptase inhibitors" (NNRTI). This class stops HIV production by attaching itself to the reverse transcriptase enzyme. As is true with the nucleoside analogues, this also prevents conversion of HIV RNA into DNA. NNRTI are Viramune (nevirapine) and Rescriptor (delaverdine).
war12 Protease Inhibitors (PI) such as Invirase (saquinavir methylate), Crixivan (indinavir), Norvir (ritonavir), and Viracept (nelfinavir) work at the final stage of the virus reproduction cycle - just as the copies of the viruses are about to depart from the original CD4+ cell, to infect other cells. There drugs prevent the HIV copies from being successfully assembled and released to do their damage.
Also check out these sites:

Gulf Coast Community Care's New Directions program

"21st century HIV" Ezine

email: [email protected]

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