Retroviruses (HIV, HTLV)

Question 1

what is the biology of HIV?

Answer 1

enveloped with 2 copies of single stranded +RNA

Question 2

what Virus attachment proteins (VAP) found on the envelope of HIV?

Answer 2

GP 120

GP 41

Question 3

what is the major capsid protein found in HIV?

Answer 3

p24

Question 4

what enzymes does HIV have?

Answer 4

integrases

proteases

reverse transcriptase

Question 5

which of the 2 membrane proteins in HIV will define its tropism?

Answer 5

GP 120

Question 6

what cells does HIV target?

Answer 6

CD4+ cells

Question 7

antiviral drugs for HIV will target what protein of the virus?

Answer 7

gp 41

Question 8

HIV protein Gp 120 will bind to what cell and what co-receptor if it’s M tropic?

Answer 8

it binds to CD4+ (memory CD4 T cells, Dendritic cells, macrophages) cells and its co-receptor CCR5

Question 9

HIV protein Gp 120 will bind to what cell and what co-receptor if it’s T tropic?

Answer 9

if its T tropic it binds to CD4+ (activated T cells) cells and CXCR4

Question 10

what will the HIV Gp 41 protein do?

Answer 10

it will fuse the viral envelope with cell plasma membrane

Question 11

what is the first stage of HIV replication?

what symptoms are seen?

Answer 11

1st stage = we will replicate in the macrophages and dendritic cells in the lymph nodes

(swollen lymph nodes, and high virus, no antibodies)

Question 12

what is the second stage of HIV replication?

Answer 12

2nd stage = virus lives inside T cells, disseminates throughout body but remains latent, it is in DNA form, low HIV virus, we have high antibodies

Question 13

what is the 3rd stage of HIV replication?

Answer 13

3rd stage = virus is all over, shifts to CXCR4 in CD4 and attacks our active T cells and strats making many virion particles which will look for GP120

Question 14

where do we find the largest amount of cases of HIV-1 infection?

Answer 14

sub-saharan africa

Question 15

where do we find the largest amount of cases of HIV-2 infection?

Answer 15

West africa

Question 16

who is at risk of being transmitted HIV?

Answer 16

intravenous drug abuser (sharing needles)

sexually active individuals (homosexuals, prostitutes)

newborns of HIV positive mothers

organ transplant patients

Question 17

what cells are most prone to infection by AIDS and what cells are used for latency by the virus?

Answer 17

T cells and macrophages

CD4+ T cells by incorporating DNA into host genome

Question 18

what individuals are most prone to be resistant to HIV infection?

Answer 18

CCR5 receptor deficient individuals

Question 19

if there is a mutation in the GP 120 protein of HIV, how will this affect its tropism?

Answer 19

its tropism will shift from M-tropic to T-tropic

Question 20

what is HIV’s pathogenesis?

Answer 20

1) lytic infection of CD4 T cells (having the virus infect start to infect some macrophages)
2) reduction in CD4 T cell numbers

Question 21

what happens when you are have the HIV acute illness?

what symptoms are seen?

Answer 21

will see drop in CD4+ cell count

flu-like symptoms are seen

Question 22

what happens when you have HIV latent infection?

what symptoms are seen?

Answer 22

the virus is in provirus form

test will be positive for HIV antibodies

destruction of CD4 cells will continue

no symptoms are seen

Question 24

what happens during the symptomatic phase of HIV?

what symptoms will be seen?

Answer 24

CD4+ cell count is less than 500

increased level of virus

weight loss, continual diarrhea, extreme fatigue, **oral thrush **

Question 25

what bacteria causes oral thrush seen in HIV symptomatic phase?

Answer 25

candida

Question 26

what happens in full blown AIDS by HIV virus?

what symptoms are seen during this phase?

Answer 26

CD4 is less than 200

antibody test is negative

kaposi sarcoma, thrush, severe CMV, dementia

Question 27

what are 3 opportunisitc infecions seen in AIDS?

Answer 27

1) Pneumocystis jiroveci Pneumonia (PCP)
2) Candidiasis (oral thrush)
3) cryptococcocis (meningitis)

Question 28

what fungal infection is most defining of AIDS?

Answer 28

PCP

Question 29

what is the most common fungal infection of the CNS?

Answer 29

cryptococcosis

Question 30

what is the most common fungal infection overall?

Answer 30

candidiasis

Question 31

what are 2 of the most common bacterial infections found in AIDS?

Answer 31

1) Mycobacterium avium intracellular complex (MAC) (lung and esophagus infection)
2) Salmonella typhimurium

Question 32

what is the 2 most common viral infections found in AIDS patients?

Answer 32

1) CMV
2) Herpes Simplex Virus

Question 33

what does CMV lead to in AIDS?

Answer 33

• retinitis
• esophagitis
• colitis (diarrhea)

cholecystitis

Question 34

How do CMV infections differ in immunocompetent vs. immunosuppressed patients?

Answer 34

In immunocompetent patients, an acute CMV infection results in a syndrome resembling acute infectious mononucleosis.

In the immunosuppressed patient, CMV disease, whether acquired primarily or as a result of reactivation, may be a disseminated, fulminant, and lethal disease with multiorgan involvement.

Question 35

what are 2 common parasitic infections found in AIDS patients?

Answer 35

1) CNS toxoplasmosis
2) Cryptosporidiosis

Question 36

what is the most common pathogen found in diarrhea?

Answer 36

cryptosporidiosis

Question 37

what is the most common focal space occupying lesions in AIDS patients?

Answer 37

CNS toxoplasmosis

Question 38

what are 5 AIDS determining malignancies?

what virus causes each of these malignancies?

Answer 38

1) kaposi’s sarcoma - HHV-8
2) Burkitt’s lymphoma- EBV
3) Primary CNS lymphoma - EBV
4) Invasive cervical cancer- HPV
5) Anal squamous cell carcinoma - HPV