L16: HIV/AIDS Flashcards Preview

Medical Virology (UoG) Midterm 2 > L16: HIV/AIDS > Flashcards

Flashcards in L16: HIV/AIDS Deck (12):
1

Desribe the 7 major proteins that make up an HIV particle.

Surface glycoprotein
- gp120
- gp41
- Major virus antigen
Matrix
- lines envelope
- derived from gag gene
Capsid
- derived from gag gene
- protects core
Nucleocapsid
- derived from gag gene
- protects the genome
- forms the core
Protease
- essential for gag protein cleavage during maturation
RT
- conversion of ssRNA genome to dsDNA
Integrase
- encoded by pol gene
- necessary for virus integration into host genome

2

Briefly describe HIV pathogenesis.

- HIV enters the body via musocal surfaces or blood
- binds to DCs which carry the virus to CD4+ T cells
- T cells travel to lymphoid tissues
- Viraemia leads to widespread dissemination of the virus
- HIV-specific IR occurs but infection persists
- Lymphocyte depletion occurs over an extended period of time
- Immune system is compromised --> AIDS

3

What is a provirus?

An inactive form of a virus that has been integrated into the host genome

4

What is the main difference between M and T tropic strains of HIV?

- M-tropic strains use CCR5 co-receptors to gain entry predominantly into CD4+ T memory cells, whereas T-tropic strains utilise CXCR4 as a co-receptor for entry into naive CD4+ T cells

5

What are the 5 types of HIV treatment?

- RT inhibitors
- Protease inhibitors
- Fusion/entry inhibitors
- Integrase inhibitors
- Combination (HAART) therapy

6

What is the function of 'Tat'?

- Transcriptional activator --> promotes elongation

7

What is the function of 'Rev'?

- Induces nuclear export of unspliced viral RNA

8

What is the function of 'Vpr'?

- Regulates nuclear import of HIV pre-integration complex
- Required for virus replication in non-dividing cells
- induces cell cycle arrest in G2

9

What is the function of 'Vif'?

- Inhibits APOBEC3G, preventing innate antiretroviral IR

10

What is the functin of 'Nef'?

- Downregulates CD4 and MHC
- Enhances viral activity by causing T cell activation

11

What is the functin of 'Vpu'?

- Induces CD4 degradation
- Counteracts tetherin --> enhances virion release

12

What is reverse transcriptase and how does it contribute to HIV infection?

- RT allows the +ssRNA genome to be converted to dsDNA (with help from RNase H) and works with integrase in order to integrate into the host genome