HIV Flashcards
virus core
major caspid protein p24
nucleocapsid p7/p9
two RNA genome copies
protease, reverse transcription, integrase
matrix protein
p17
glycoprotein
gp120
gp41
proviral genome
gag, pol, env
gag and pol
premature proteins (which are converted into maturee proteins with portease)
nef gene
kinase protein - reduces CD4 and MHC molecules on virus infected cells
viral polymerase
low infidelity rates - 1 mistake every 100000 nucleotide replication
entry requires
CD4 molecule
gp 120 binds to
CD4 - conformational changes on gp 120 for binding with:
CCR5, CXC R4 (cell surface chemokine receptors)
gp41
gp41 conformational chnage occurs - it inserts into membrane - virus fusion with the cell occurs
R5 strains HIV
uses CCR5 as their coreceptor - CCR5 re present on both macrophages and T cells
X4 strains HIV
use CXCR4 as their co receptor- only present on T cells
T cell depletion
lytic HIV infection of cells
- infection of thymic progenitor
- infection of accessory cells that help in t cell maturation
- activation induced death
- giant cells - ballooning - cell death
- uninfected cell bind to gp120 - apoptosis
- infected cells killed by cytotoxic t cells
giant cells
fusion of uninfected (CD4) and infected (gp120) cells
CD4:CD8 ratio in AIDS
less than 0.5 (normal is 1:2)
vpr gene
helps virus to multiply in terminally differentiated macrophages (viruses stay in intracellular vesicles)
targets for hiv
t cells, macrophages, follicular DC, mucosal DC
B cells activation due to HIV
binding with gp120
activation of macrophages and release of IL-6
encapsulated bacterias
require antibodies response for combating
Neurological deficit in HIV infection
because of cytokines (like TNF) produced by activated macrophages and other viral products
acute phase of HIV
3-6 weeks after infection, viral multiplication, viremia, decrease in CD4+ t cells
Chronic phase of HIV
immune system intact CD4+ rise again LAP oppurtunistic infections - minor viral replication continues
crisis phase of HIV
catastrophic break down of host defense fever weight loss fatigue diarrhea CD4+ T cells below 500 cells per mciro L oppurtunistic infections neurological manifestations Neoplasmas
three categories of AIDS patients
CD4+ count
> 500 per micro L
<200 - >500 micro L
<200 micro L
oppurtunistic infections in AIDS
P. jiroveci Candida Isospora belli, cryptosporidium - diarrhea Myobaterium tb - MAC - infections toxoplasmosis in brain cryptococcal meningitis salmonella, shigella diarrhea ulcerating oral and perianal herpes h. influenzae, s. pneumoniae cmv - retinitis and enteritis
Kaposi’s sarcoma
