Viral sexually transmitted infections I

Question 1

What is the major nucleocapsid protein for HIV?

Answer 1

p24

Question 2

What is the major matrix protein for HIV?

Answer 2

p17

Question 3

What is the HIV attachment protein?

Answer 3

gp120

Question 4

What is the HIV fusion protein?

Answer 4

gp41

Question 5

What is the genome for HIV?

Answer 5

+ssRNA

Question 6

Is HIV enveloped or non-enveloped?

Answer 6

Enveloped

Question 7

HIV belongs to what virus family?

Answer 7

Retroviridae

Question 8

What is required for maturation of HIV virions?

Answer 8

Extracellular protease-mediated cleavage of polypeptide

Question 9

Where does gp120 bind during HIV infection?

Answer 9

CD4

Question 10

Conformational change in gp120 allows binding to what coreceptors?

Answer 10

CCR5 and CXCR4

Question 11

What is required for HIV entry into the cell?

Answer 11

Binding of coreceptor

Question 12

R5 tropic HIV viruses infect what cell types best?

Answer 12

Monocytes / macrophages, microglia

Question 13

What percentage of patients transfer from R5 to X4 viruses during HIV infection?

Answer 13

40%

Question 14

Deletion in what coreceptor gene inactivates binding to gp120?

Answer 14

CCR5 delta-32 gene

Question 15

What mediates the fusion between viral envelope and plasma membrane?

Answer 15

gp41

Question 16

What kind of genome copy is made by reverse transcriptase?

Answer 16

Linear dsDNA copy of HIV RNA genome

Question 17

What is the HIV provirus?

Answer 17

When viral DNA is incorporated into host genome (permanent)

Question 18

How do HIV virions exit the cell?

Answer 18

Budding through plasma membrane at lipid rafts

Question 19

Viral proteases cleave what polyproteins during virion maturation?

Answer 19

Gag and gag-pol

Question 20

What is required for infectivity of the HIV virion?

Answer 20

Protease cleavage

Question 21

Is HIV infection more efficient male-to-female or female-to-male?

Answer 21

Male-to-female

Question 22

What is the overall HIV transmission risk for mother-to-child transmission?

Answer 22

25%

Question 23

What is the HIV transmission risk for mother-to-child transmission AT BIRTH?

Answer 23

50-65%

Question 24

What is the risk of HIV transmission risk for needle stick?

Answer 24

0.3%

Question 25

What is the risk of HIV transmission from mucous membrane contact?

Answer 25

0.09%

Question 26

What can be measured in blood during the acute phase of HIV infection?

Answer 26

p24 capsid and viral genome

Question 27

When does chronic lymphadenopathy occur during HIV infection?

Answer 27

After viral replication goes down and anti-HIV antibodies (gp120) start going up

Question 28

When does acute HIV infection occur?

Answer 28

3-6 weeks following infection

Question 29

What are some of the ways in which HIV escapes the immune system?

Answer 29

1. Antigenic drift of gp120 2. Inactivation of key immune response elements 3. Cell to cell fusion

Question 30

What is the median time of clinical latency in untreated patients?

Answer 30

10 years

Question 31

What is the HIV set point?

Answer 31

Predicts progression rate to AIDS in untreated patients

Question 32

What causes oral hairy leukoplakia?

Answer 32

Epstein Barr virus

Question 33

In order of diagnostic detectability, what HIV antigens are present in blood first?

Answer 33

1. RNA 2. p24 3. HIV antibody

Question 34

What is the order of testing for HIV?

Answer 34

1. HIV 1/2 antigen/Ab combination immunoassay 2. HIV 1/2 Ab differentiation immunoassay 3. HIV-1 PCR

Question 35

What does the HIV 1/2 antigen / Ab combination assay look for?

Answer 35

Anti-p24 antibody and viral antigen

Question 36

What test is performed if the antigen / Ab combination assay is positive?

Answer 36

Antibody differentiation immunoassay

Question 37

What are the contraindications for HIV entry inhibitors?

Answer 37

1. Not recommended for initiation of treatment in newly diagnosed patients 2. Generally reserved for people who have been on antiretroviral therapy for a while

Question 38

What are the two HIV entry inhibitor types?

Answer 38

1. Chemokine coreceptor antagonists 2. Fusion inhibitors

Question 39

What do the chemokine receptor antagonists do?

Answer 39

Bind to coreceptor and prevent interaction with gp120

Question 40

What do the fusion inhibitors do?

Answer 40

Bind to gp41 and prevent conformational change needed for fusion of viral envelope with cellular plasma membrane

Question 41

What are the two types of reverse transcriptase inhibitors?

Answer 41

1. Nucleoside inhibitors (NRTIs) 2. Nonnucleoside inhibitors (NNRTIs)

Question 42

What do the nucleoside inhibitors do? (NRTIs)

Answer 42

Incorporated into growing DNA chain during provirus synthesis - cause chain termination

Question 43

What do the nonnucleoside inhibitors do? (NNRTIs)

Answer 43

Bind to reverse transcriptase and inhibit its activity

Question 44

What do integrase inhibitors do?

Answer 44

Block integration of DNA copy of viral genome into cellular genome

Question 45

What do the protease inhibitors do?

Answer 45

Bind to active site and inhibit protease activity

Question 46

What is the standard of care for ARV therapy?

Answer 46

1. Combinations of at least three drugs 2. 1 NNRTI + 2 NRTIs 3. 1 PI + 2 NRTIs 4. 1 II + 2 NRTIs 5. Note - 2 NRTIs always used