HIV

Question 1

How is HIV transmitted?

Answer 1

Bodily secretions (STI)
Infected blood (intravenous drug use)

Question 2

What happens during the first 2-6 weeks of an HIV infection?

Answer 2

Sometimes patients have flu-like symptoms
CD4 T cell levels dip below 500 cells/mL

Question 3

What is the asymptomatic phase of HIV?

Answer 3

Seroconversion
CD4 T cell levels slowly decline over 2-20 years

Question 4

What is seroconversion?

Answer 4

Antibodies to virus are present in serum

Question 5

What is the symptomatic phase of HIV?

Answer 5

CD4 T cell levels dip below 500 cells/mL and opportunistic infections take hold

Question 6

What is AIDS?

Answer 6

When CD4 T cell levels reach 0 cells/mL and quickly results in death

Question 7

What does the membrane surface of HIV carry?

Answer 7

Envelope glycoprot3eins

Question 8

What does each capsid in HIV carry?

Answer 8

Two RNAs and reverse transcriptase which copies RNA into DNA

Question 9

Where does HIV undergo fusion?

Answer 9

At the cell membrane

Question 10

What does HIV bind to on the T cell?

Answer 10

CD4 and a chemokine co-receptor

Question 11

What happens when the viral envelope fuses with the cell membrane?

Answer 11

The capsid uncoats itself and the viral genome enters the cell

Question 12

What does an HIV-1 envelope glycoprotein contain?

Answer 12

Conserved regions
Variable regions
Fusion peptide
The extracellular part of the protein is gp120 while the intracellular part is gp41

Question 13

What type of people are resistant to HIV infections?

Answer 13

People with a mutation in CCR5

Question 14

What cell types of infected by HIV?

Answer 14

Cells that have CD4 and the chemokine receptor

Question 15

What is an alternate chemokine receptor that HIV can bind to?

Answer 15

Cxcr4

Question 16

What exposes the CCR5 receptor binding site?

Answer 16

HIV gp120 binding to CD4 which causes a conformational change

Question 17

What does HIV binding to the co-receptor induce?

Answer 17

A second conformational change exposing the fusion peptide

Question 18

What does reverse transcriptase do?

Answer 18

Copies the ssRNA into dsDNA

Question 19

What does integrase do?

Answer 19

Inserts DNA into the genome as a provirus

Question 20

What is the significance of HIV being error-prone?

Answer 20

It can tolerate all sorts of mistakes and continue to synthesis DNA

Question 21

What is NFkappaB turned on by?

Answer 21

The activation of infected T cells or macrophages

Question 22

What does T cell activation induce (HIV)?

Answer 22

Low-level transcription of provirus

Question 23

What does the Tat gene do?

Answer 23

Amplifies transcription of viral RNA

Question 24

What does the Rev gene do?

Answer 24

Increases transport of singly spliced or unspliced viral RNA to the cytoplasm

Question 25

What are Gag, Pol, and Env proteins translated and assembled into?

Answer 25

Virus particles which bud form the cell