Retroviruses (HIV, HTLV) Flashcards
(38 cards)
what is the biology of HIV?
enveloped with 2 copies of single stranded +RNA
what Virus attachment proteins (VAP) found on the envelope of HIV?
GP 120
GP 41
what is the major capsid protein found in HIV?
p24
what enzymes does HIV have?
integrases
proteases
reverse transcriptase
which of the 2 membrane proteins in HIV will define its tropism?
GP 120
what cells does HIV target?
CD4+ cells
antiviral drugs for HIV will target what protein of the virus?
gp 41
HIV protein Gp 120 will bind to what cell and what co-receptor if it’s M tropic?
it binds to CD4+ (memory CD4 T cells, Dendritic cells, macrophages) cells and its co-receptor CCR5
HIV protein Gp 120 will bind to what cell and what co-receptor if it’s T tropic?
if its T tropic it binds to CD4+ (activated T cells) cells and CXCR4
what will the HIV Gp 41 protein do?
it will fuse the viral envelope with cell plasma membrane
what is the first stage of HIV replication?
what symptoms are seen?
1st stage = we will replicate in the macrophages and dendritic cells in the lymph nodes
(swollen lymph nodes, and high virus, no antibodies)
what is the second stage of HIV replication?
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
what is the 3rd stage of HIV replication?
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
where do we find the largest amount of cases of HIV-1 infection?
sub-saharan africa
where do we find the largest amount of cases of HIV-2 infection?
West africa
who is at risk of being transmitted HIV?
intravenous drug abuser (sharing needles)
sexually active individuals (homosexuals, prostitutes)
newborns of HIV positive mothers
organ transplant patients
what cells are most prone to infection by AIDS and what cells are used for latency by the virus?
T cells and macrophages
CD4+ T cells by incorporating DNA into host genome
what individuals are most prone to be resistant to HIV infection?
CCR5 receptor deficient individuals
if there is a mutation in the GP 120 protein of HIV, how will this affect its tropism?
its tropism will shift from M-tropic to T-tropic
what is HIV’s pathogenesis?
1) lytic infection of CD4 T cells (having the virus infect start to infect some macrophages)
2) reduction in CD4 T cell numbers
what happens when you are have the HIV acute illness?
what symptoms are seen?
will see drop in CD4+ cell count
flu-like symptoms are seen
what happens when you have HIV latent infection?
what symptoms are seen?
the virus is in provirus form
test will be positive for HIV antibodies
destruction of CD4 cells will continue
no symptoms are seen
what happens during the symptomatic phase of HIV?
what symptoms will be seen?
CD4+ cell count is less than 500
increased level of virus
weight loss, continual diarrhea, extreme fatigue, **oral thrush **
