Retroviruses 2 Flashcards
CXXR4 role
co receptor for T tropic HIV. binds SDF-1 which can block T tropic infection
Vir role
restriction factor, causes cellular antiviral protein to be degraded so that it cannot be incorporated into new virions where it would block RT in the next cell by inducing massive mutations in viral DNA
level of CD4 depletion AIDS phase
Serology cant detect HIV infection until
4-6 weeks post infection
Classes of HIV drugs
RT inhibitor, Protease inhibitor, Fusion inhibitor, Entry inhibitor, integrase inhibitor
___ clears viremia during asymptomatic phase, CD4 declines
FDC
6 additional accessory proteins required for HIV pathogenesis
Vif, Vpr, Vpu, Nef, Tat, Rev
mechanism of direct killing via HIV
massive virus production > membrane leakage AND syncitia of infected cells fuse via Env (infected) CD4/CCR5 (healthy) interactions AND apoptosis induced by infection
indirect effects of killing via HIV
CD4 cells >> immune response kills infected cells, soluble gp120 binds uninfected cells, which are then susceptible to ADCC
CCR5 role
co receptor for M tropic HIV, receptor for RANTES, MIP-1a, MIP 1B
methods of testing
Serology, RNA RT-PCR (virus in blood) Real-time RT-PCR (quantifies virus in blood)
RANTES, MIP-1a, MIP-1B role
chemokines specifically inhibit M tropic HIV by occupying CCR5
infect primary Tcells and T cell lines, but not macrophages, associated with progression and arise at AIDS stage
T-tropic HIV
Dendritic cell role in HIV infection
can be infected, disseminate, but not productively infected
homozygous 32bp deletion in ___ gene makes individual incredibly resistant to HIV infection
CCR5
macrophage role in HIV infection
infected but not efficiently killed, HIV resevoir
after exposure co-receptor binding site via conformational change in env, ___ domains are exposed and enter cell membrane
gp41 fusion domains
during asymptomatic phase ___ traps virus, keeping viremia low, but nodes (especially ____) are major sites of replication
FDC traps virus, but GALT major region of replication
Tat role
transactivator of transcription (required for transcription)
Stromal derived factor 1 role (SDR-1)
cytokine, natural ligand for CXRC4, coreceptor for T tropic
Co-receptor engagement triggers ____ of the N and C terminal helical regions of gp41 and fuses them together
snapback
initial receptor for HIV
CD4
Rev role
regulator of virion expression - allows strucutral gene expression by promoting transport of unspliced RNA to cytoplasm
infect primary Tcells and macrophages but NOT Tcell lines, responsible for inititial infection and transmission, predominant in asymptomatic
M tropic
Vpu role
promotes virion releasse from cells by inhibiting host tetherin, works on other enveloped viruses
in initiation of binding, ___ contacts CD4 and induces a conformtion change in ___ to expose the coreceptor binding site
Env
duration of HIV in body
75 years (memory Tcells)
Microglia role in HIV
infected > contribute to AIDS dementia
