B3-071A Retroviruses and HIV-1

Question 1

oncogene hypothesis

Answer 1

viral and oncogenic material exist as genetic elements

Question 2

Class I: Retrotransposons

Answer 2

Two stages:
DNA to RNA by transcription, then RNA to DNA by reverse transcription

Question 3

Class 2: DNA transposons

Answer 3

cut from genome by a transposase and inserted into another region of the genoma

Question 4

is HIV-1 enveloped?

Answer 4

yes

Question 5

HIV is _______, meaning it contains 2 copies of the viral RNA

Answer 5

diploid

Question 6

HIV contains a ___________ enzyme

Answer 6

reverse transcriptase

Question 7

are retroviruses endogenous or exogenous?

Answer 7

both :)

Question 8

HIV-1 evolved from

Answer 8

SIVcpz

Question 9

the ___ group resulted in the HIV-1 pandemic

Answer 9

M

Question 10

HIV-2 evolved from

Answer 10

SIVsm

Question 11

HIV-1 is further classified into subtypes based on

Answer 11

env and gag genes

Question 12

how many subtypes of HIV-1 are there currently?

Answer 12

9

Question 13

which subtype of HIV-1 is most prevalent?

Answer 13

subtype C

Question 14

p24 is the

Answer 14

capsid protein

Question 15

p17 is the

Answer 15

matrix protein

Question 16

HIV-1 has the _____ gene, while HIV-2 and SIV are missing it

Answer 16

vpu gene

Question 17

p7

Answer 17

nucleocapsid protein

Question 18

p17, p24, p7, and p6 are encoded by the _____ gene

Answer 18

gag

Question 19

p10

Answer 19

protease

Question 20

p66, p51

Answer 20

reverse transcriptase

Question 21

p32

Answer 21

integrase

Question 22

p10, p66, p51, and p32 are encoded by the ____ gene

Answer 22

pol

Question 23

rev and tat are located in the ____ gene

Answer 23

env

Question 24

gp120, gp41

Answer 24

envelope glycoprotein

Question 25

gp120 and gp41 are encoded by the ____ gene

Answer 25

env

Question 26

transactivation of viral and cellular genes

Answer 26

tat

Question 27

regulation of RNA splicing and promotion of export of mRNA to cytoplasm

Answer 27

rev

Question 28

alteration of cell activation signals; down regulation of CD4 and MHC1 from the cell surface

Answer 28

nef

Question 29

virion infectivity, inhibits cytidine deaminase activity

Answer 29

vif

Question 30

causes cells to enter G2 arrest; transport of pre-integration complex into the nucleus

Answer 30

vpr

Question 31

decrease surface expression of CD4, facilitates virion release, has ion channel activity

Answer 31

vpu

Question 32

gp160

Answer 32

env precursor molecule

Question 33

where is gp160 synthesized

Answer 33

RER

Question 34

after synthesis, gp160 is transported to the

Answer 34

golgi

Question 35

gp160 is cleaved by ______ into gp120 and gp41

Answer 35

a host enzyme

Question 36

the envelope glycoprotein of HIV-1 binds to the

Answer 36

CD4 receptor and coreceptor

Question 37

what is responsible for the fusion of viral and host cell plasma membrane during viral entry?

Answer 37

gp41

Question 38

the env is responsible for determining the cell ______ of various isolates

Answer 38

tropism

Question 39

in early infection [cell type] are infected via the [receptor]

Answer 39

macrophages, CCR5

Question 40

CCR5+ cells include

Answer 40

macrophages T cells Langerhans cells

Question 41

in late stage infection [cell type] are infected via [receptor]

Answer 41

T cells; CXCR4

Question 42

CCX4R5

Answer 42

infects both CD4 t cells and macrophages

Question 43

gp120 binds to

Answer 43

CD4, then CCR5

Question 44

gp41 induces a conformational change forming the

Answer 44

prehairpin intermediate

Question 45

when the virus enters the cell and is uncoated

Answer 45

reverse transcriptase converts it to linear ds DNA

Question 46

integrase

Answer 46

integrates the viral DNA into the host cell DNA

Question 47

is an HIV-1 virus mature at exocytosis?

Answer 47

no, need viral protease to form nucleocapsid

Question 48

set point

Answer 48

level of viremia at the end of acute stage of infection

Question 49

the higher the set point the _______ progression into AIDS

Answer 49

faster

Question 50

mean time from infection to AIDS is

Answer 50

10 years

Question 51

the primary stage of infection is characterized by

Answer 51

non-specific prodrome headache, muscle ache, sore throat, fever, lymphadenopathy, malaise, GI upset

Question 52

clinical latency

Answer 52

asymptomatic period

Question 53

is there replication in the asymptomatic period?

Answer 53

yes, constant constant turnover of infected T cells

Question 54

gradual decline of circulating CD4 T cells during the asymptomatic phase is due to

Answer 54

constant turnover and reinfection of new T cells

Question 55

towards the end of the asymptomatic period there is an

Answer 55

increase in viral load

Question 56

AIDS is defined as

Answer 56

a CD4 count <200 OR being HIV-1 positive with an AIDS defining illness

Question 57

protozoal AIDS opportunistic infections

Answer 57

toxoplasmosis, crytosporidosis

Question 58

fungal AIDS opportunistic infections

Answer 58

PJP candidiasis crytococcosis histo coccidiodo

Question 59

bacterial AIDS opportunistic infections

Answer 59

mycobacterium avium atypical mycobacterial disease salmonella septicemia recurrent pyogenic infections

Question 60

viral AIDS opportunistic infections

Answer 60

CMV, HSV, VZV, EBV, PML

Question 61

HAND

Answer 61

viruses in CNS become M-tropic (instead of T cell tropic) and target microglia cells

Question 62

rapid progressors develop AIDS within

Answer 62

2-3 years

Question 63

rapid progressors have _______ viral set point

Answer 63

high

Question 64

long term nonprogressors maintain CD4 counts for

Answer 64

>7 years

Question 65

viremic controllers maintain CD4 counts

Answer 65

<500

Question 66

elite suppressor or controllers maintain

Answer 66

undetectable viral loads without ART

Question 67

can virus be isolated from elite suppressors?

Answer 67

yes

Question 68

initial screening test for HIV

Answer 68

antibody or antibody/antigen tests

Question 69

confirmatory assays are done via

Answer 69

western blot traditionally, but multispot assay more recently

Question 70

if the multispot is negative or indeterminate

Answer 70

NAT

Question 71

despite ART treatment ____________ persists

Answer 71

low level replication

Question 72

the size of the reservoir of virus in effectively treated patients may be as low as

Answer 72

10^6 to 10^7 infected cells

Question 73

after discontinuation of ART

Answer 73

virus replication rebounds