BMS 451 Lecture Notes - Lecture 21: Antibody, Antigenic Variation, Glycosylation
13 Dec 2016
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Document Summary
Two viruses- hiv-1; high virulence, hiv-2; low(er) virulence. Retroviruses are rna-viruses that go through a dna intermediate to replicate. Depends on the action of reverse transcriptase (rna-dependent dna polymerase) encounter. Spread by blood, semen, vaginal secretions, breast milk. Transmission by sexual contact, iv drug use or vertically. High prevalence in africa, europe has high rates due to drug use. Blood transfusions have the highest risk of contracting hiv entry. Hiv binds to cd4 - main source for trophism. Main coreceptor at the main site of infection is the ccr5 - a chemokine receptor typically involved in responding to immune signals. Homozygotes in ccr5-/- are very resistant to hiv infection ~10% of europeans. Course of infection is slower and delayed replication/spread rna genome enters host cell, reverse transcriptase produces dna, virus integrates into host genome- provirus. Productive replication occurs and local susceptible cells die out.
