NATS 1670 Lecture Notes - Reverse Transcriptase, Envelope Glycoprotein Gp120, Retrovirus

• School: York University
• Department: Natural Science
• Course: NATS 1670
• Professor: Motti Anafi

Document Summary

Why is it so difficult to develop a vaccine against hiv: 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. 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: 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, high error rate. 1 error in every 5,000 nucleotides: hiv genome has approximately 10,000 nucleotides, therefore every new virus has (on average) two mutations!