Flashcards in HIV Deck (18)
core and matrix proteins; p24
membrane glycoproteins: gp120 (outer) and gp41 (transmembrane)
Reverse transcriptase, protease, and integrase
Positive regulator of transcription
Allows export of transcripts from the nucleus
Affects particle infectivity
Viral protein R. Transport of DNA to nucleus. Augments virion production. Cell cycle arrest.
Viral protein U. Promotes intracellular degradation of CD4 and enhances release of virus from cell membrane.
Augments viral replication. Down-regulates CD4 and MHCH
What is the major co-receptor for macrophage-tropic strains of HIV?
What is the major co-receptor for T cell-tropic strains of HIV?
Most common strain of HIV in U.S.
HIV-1 Group M Subtype B
Properties of Stage I HIV
Acute retroviral syndrome -- highly contagious
30% of patients asymptomatic; others have flu-like symptoms
1. Primary infection of blood, mucosal cells
2. Infection established in lymphoid tissues
3. Acute HIV syndrome, spread throughout body
4. Immune response
Properties of Stage II HIV
Establishment of chronic infection; virus trapped in lymphoid tissues by follicular dendritic cells
Low-level viral replication for several years
Properties of Stage III HIV
Destruction of lymphoid tissue
Defining opportunistic illnesses
Stage 3-Defining Opportunistic Illnesses in HIV infection
Steps of HIV replication
1. Virus binds with CD4 on T cell surface via gp120
2. Binding induces conformational change that opens up site for co-receptor binding (CCr5: T cell / CXCr4: Macrophage)
3. HIV RNA, protease, integrase, and reverse transcriptase enter cell
4. Viral DNA is formed by reverse transcriptase in cytoplasm, then transported across nucleus via protein R, and integrated into host DNA via integrase --> now a provirus
5. New viral RNA is formed from host+viral DNA
6. New RNA transported out of nucleus via tat and and rev
7. New RNA is used to make viral proteins
8. New RNA and proteins move to cell surface and a new, immature HIV forms
9. New virus/proteins mature via protease, are exocytosed