Macrophage – the Trojan horse for HIV, the AIDS virus
• Macrophages can be HIV-infected but are not destroyed themselves by the virus.
• HIV can be integrated to their genome
• Macrophages carry virus into different organs
o Form a reservoir outside the blood (e.g. brain)
• HIV virus infects patient via macrophages in semen and in the female genital tract
• Macrophages sustain HIV production for a long time
Potential “Hiding Places” for HIV
Why is it so difficult to develop a vaccine against HIV?
1) Antibodies response against HIV are not sufficient to eliminate the virus from the body.
Antibodies seems to be counter-productive in our ability to react against HIV. In other words,
it’s better off to be without Antibodies instead of having Antibodies
Why there is an opposite correlation between higher levels of antibodies against HIV
and the amount of T helper (CD4 +) cells in AIDS patients?
Infection of macrophages by HIV may be enhanced by antibodies against the virus • HIV survives in macrophages
• Antibodies response against the virus is counter-productive: the virus is opsonized
by anti gp120 antibodies which bind to macrophage Fc receptors
A problem with the development of HIV vaccines
2) High Mutation Rate
High Mutations Rate of RNA Viruses
• HIV is a retrovirus
• Retroviruses use their reverse transcriptase to replicate their genome
• Reverse transcriptase is not linked to any repair mechanism