Human immunodeficiency virus

Question 1

transmission

Answer 1

contact with bodily fluids: blood, semen, vaginal secretions and breast milk
* sex
* infection drug use
* mother-to-child

Question 2

features of retrovirus

Answer 2

contain RNA genomes that get reverse transcribed into DNA
* virus genomes permanently integrate into the host genome as a provirus

Question 3

morphology

Answer 3

diploid: 2 identical copies of (+) ss RNA

Question 4

gp120

Answer 4

binds to CD4 receptor and a chemokine co-receptor on host cell (attachment)

Question 5

gp41

Answer 5

facilitate fusion of viral and cell membranes

Question 6

3 activities of reverse transcriptase

Answer 6

1. DNA synthesis from the RNA template
2. Ribonuclease H (RNA degradation)
3. DNA-dependent DNA synthesis

Question 7

establishes

Answer 7

latency

Question 8

replication

Answer 8

cell transcribes provirus into mRNA
* HIV genomic RNA
* mRNA is translated inot long protein chains

Question 9

assembly

Answer 9

viable HIV virions released by budding
* as CD4+ T cells die, host becomes vulnerable to opportunistic infections

Question 10

what are the main cellular targets of HIV?

Answer 10

• M- tropic (“R5”) HIV strains
• T-tropic (“X4”) HIV strains

Question 11

M-tropic (“R5”) HIV strains

Answer 11

typically infects macrophages
use CD4 and CCR5 receptors
* predominate early in infection

Question 12

T-tropic (“X4”) HIV strains

Answer 12

infects only CD4+ T cells
Use CD4 and CXCR4 receptors
* predominate later in an infection

Question 13

stage 1

Answer 13

acute/primary HIV infection

Question 14

stage 2

Answer 14

clinical latency

Question 15

stage 3

Answer 15

acquired immunodeficiency syndrome (AIDS)

Question 16

what is the number 1 cause of death in HIV patients

Answer 16

mycobacterium tuberculosis

Question 17

what are four selective targets of HIV retroviral drugs

Answer 17

• reverse transcriptase
• entry/fusion inhibtors
• integrase inhibitors
• protease inhibtors

Question 18

reverse transcriptase lacks

Answer 18

proofreading activity

Question 19

CCR5 delta 32 allele

Answer 19

a naturally occuring mutant allele of the CCR5 gene where deletion of 32 base pairs makes the receptor nonfunctional