HIV Flashcards
Describe HIV structure.
- Viral genome is covered by capsid protein p24.
- Envelope contains transmembrane (gp41) and surface proteins (gp120)
- Underlying the envelope is matrix protein (p17).
- Virion contains nonstructural proteins including reverse transcriptase.
Explain HIV Pathogenesis
- Virus infects both CD4 and macrophages
- Can also infect dendritic cells
- T cells are lytically infected while macrophages are persistently infected.
Describe the clinical manifestations of HIV
Immune system makes anti-HIV antibodies. Antibody testing prior to this may not be positive.
Discuss clinical dormant stage
- Asymptomatic
2. Level of virus in blood decreases and stays at steady state
What is the HIV set point?
The stabilized HIV virus load in a person after acute phase of infection. Higher set point leads to faster progression to AIDS. Lower set point leads to slower progression to AIDS.
How does HIV avoid the immune system?
- Inactivates CD4 and macrophages
- Antigenic Drift of antigens
- Latent infections of macrophages
Describe Kaposi’s Sarcoma
Red to purple lesions on the skin or body of an HIV patient.
How does the virus affect the CNS?
Carried to CNS by macrophages. Infects microglia and astrocytes which cause slow deterioration of cognitive function.
Discuss Maraviroc
CCR5 blocker; Prevents gp120 from associating with CCR5 receptor. WONT work for viruses that use CXCR4.
Discuss T20
Fusion inhibitor; Interferes with HIV-1s ability to enter cells by blocking binding of viral envelope with CM.
Describe AZT
Nucleoside analogue of thymidine. Phosphoylated by host enzymes and incorporated into viral cDNA. Causes chain termination.
Describe integrase inhibitors
Prevents virus from integrating into the host genome; Raltegravir
Discuss HTLV and Tax gene
Tax gene product activates cellular genes encoding T cell growth factors such as IL-2 which may lead to tumor formation.
