Virology

Question 1

binds CD4, CCR5, CXCR4 on T cell or Macrophage cell membrane to mediate HIV attachment

Answer 1

Gp120

Question 2

When is CCR5 bound and where is it found?

Answer 2

Early infection by Gp120
on MQ
aka R5 strains

Question 3

When is CXCR4 bound and where is it found?

Answer 3

Late infection by Gp120
on T cells
aka X4 strains

Question 4

Homozygous CCR5 mutation =

Answer 4

immunity to HIV

Question 5

Heterozygous mutation CCR5 =

Answer 5

Slower course of HIV

Question 6

Reverse transcriptase of HIV synthesize ____ which integrates into host genome

Answer 6

dsDNA

Question 7

encodes reverse transcriptase (RT), integrase (IN), protease (PR)

Answer 7

Pol (polymerase)

Question 8

encodes HIV capsid (p24) and matrix (p17) proteins

aka CORE proteins

Answer 8

Gag

Question 9

HIV uses _____ for fusion and entry

Answer 9

gp41

Four-1 = Fus1on

Question 10

what codes for gp120 and gp41 in HIV which are formed from the cleavage of gp160

Answer 10

env (envelope) gene

Question 11

Diploid genome 2 molecules of RNA

Answer 11

HIV

Question 12

HIV AB-immunoassays during acute HIV infection phase to detect viral ___
and IgG ABs to _____

How to confirm HIV during serologic window phase

Answer 12

p24 Ag capsid

IgG ABs to HIV1/2

Nucleic acid testing (NAT aka PCR) for HIV RNA becomes [+] earlier than p24/antibodies (i.e. in the serologic window) → useful for confirming acute HIV infection

Question 13

1-2 months
what is seen in Acute HIV infection serology?
HIV RNA
CD4+
CD8+
Anti–gp120 AB

Answer 13

High RNA load ( It’s over a thousand!!!!)

Low CD4+ (~500)
Normal CD8+
Rising Anti–gp120 ABs

Question 14

0-1 month
what is seen in window period of HIV serology?
HIV RNA
CD4+
CD8+
Anti–gp120 AB

Answer 14

Rising HIV RNA (may not be detectable)

Falling CD4+ (~700-800)
Normal CD8+
No Anti–gp120 AB

Question 15

What CD4+ count = AIDS

Answer 15

<200

Question 16

During clinical latency HIV replicates in the

Answer 16

Lymph Nodes

Question 17

What kind of RNA virus is HIV (+/–)

Answer 17

+ RNA (2 copies)

Question 18

HIV encodes reverse transcriptase an _____ polymerase which transcribes ___ into ___

Answer 18

RNA-dependent DNA Polymerase

(1) single-stranded viral RNA
(2) double-stranded DNA

Question 19

The HIV virion has a _____ capsid composed of subunits of ___ (capsid protein)

Answer 19

conical capsid

p24

Question 20

The HIV virion contains a protective shell composed of subunits of ___ (matrix protein)

Answer 20

p17

Question 21

gp41 is a _____ protein and gp120 is and _____ protein

Answer 21

transmembrane

outer

Question 22

CCR5 or CXCR4 are _______ co-receptors

Answer 22

chemokine

Question 23

HIV can be transmitted sexually, parentally (IVDU), and _____ during ___, ___, ___,

Answer 23

vertically (i.e. mother to infant)

pregnancy, delivery, or breastfeeding

Question 24

Early in HIV infection, patients may develop acute retroviral syndrome, which presents with

Answer 24

Fever/ Flu-like symptoms

Question 25

HIV infection is followed by clinical latency, an asymptomatic period lasting ____ years

Answer 25

8-10

*HIV RNA levels are constant during this time

Question 26

catalyzes the integration of double-stranded viral DNA into host cell DNA

Answer 26

Integrase

Question 27

The envelope precursor protein gp160 is processed in the host cell ______ and ______ to gp120 and gp41

Answer 27

endoplasmic reticulum

Golgi apparatus

Question 28

cleaves most viral polyproteins into functional proteins

Answer 28

protease

Question 29

Neutralizing IgG antibodies primarily target ___

Answer 29

gp120

Question 30

gp120 exhibits a high degree of ___________, preventing the host from mounting an effective immune response

Answer 30

Antigenic variation

Question 31

gp120 is heavily _______, protecting it from immune surveillance

Answer 31

glycosylated

Question 32

competitively bind reverse transcriptase → prevention of nucleotide binding → inhibition of DNA elongation

Answer 32

Nucleoside reverse transcriptase inhibitors (NRTIs)

Question 33

allosterically bind reverse transcriptase → change in conformation of active site → prevention of DNA elongation

Answer 33

Non-nucleoside reverse transcriptase inhibitors (NNRTIs)

Question 34

bind integrase, preventing the incorporation of viral DNA into host cell DNA

Answer 34

Integrase inhibitors (bictegravir, dolutegravir, elvitegravir, raltegravir)

NOTICE (TEGRA)

Question 35

Side effects of ______ include neurological and psychiatric symptoms and muscle breakdown (check a CK level if your patient complains of soreness)

Answer 35

Integrase inhibitors

Question 36

____ inhibitors prevent cleavage of gag and pol polyproteins by viral protease.

The gag and pol polyprotein product is cleaved into individual functional proteins at the ___ of the viral budding process. The proteolysis step is critical for the creation of mature, infectious virions.

Answer 36

Protease

end

Question 37

blocks the CCR5 co-receptor, preventing HIV from entering the cell

Answer 37

Maraviroc (an entry inhibitor)

Question 38

Determine the HIV _____ prior to starting maraviroc, since it binds exclusively to CCR5 and not CXCR4

Answer 38

tropism

Question 39

binds gp41, preventing the fusion of the HIV membrane and the host cell membrane

Answer 39

Enfuvirtide (fusion inhibitor)

Question 40

In most cases, HIV treatment regimens should begin with an _____ inhibitor + 2 ____

Answer 40

integrase
NRTIs

(ex: dolutegravir + tenofovir and emtricitabine)