HIV infection Flashcards
CD4 T cells decrease on average by how much each year in an infected person
50 cells/mm3 per year
normal CD4 count is
500
When are the two peaks of RNA HIV copies during lifetime course
At start of the infection and very end - when CD4T cell count very low
Define AIDS
1) presence of an HIV infection
2) an opportunisitic infefction OR 2) CDT cell count <200
Which surface protein is needed for viral entry?
gp120
2 co-receptors are essential for entry
CCR5 and
CXCR4
what type of cells can HIV infect
CD4 T cells (always need a coreceptor)
macrophages, monocytes can also be infected
Ligand for CXCR4 is
SDF-1
Ligand for CCRC5 is
MIP1-alpha MIP-1 beta
Homozygotes for which coreceptor are resistant to infection
CCR5 mutations
Which pro-inflammatory cytokines increase infectivity of HIV
IL-1
TNF
IL-6
which TF binds to the LTR of HIV-1 and enhances its transcription?
NFKB
What is the immune deficiency in HIV infection
decrease number and function of CD4 T cells
What % of infected CD4T cells in vivo
1/1000 are actually infection
- direct killing of cd4t cells not the only thing
what might be the mechanism by which CD T cells are dying
Activation induced cell death
- e.g. by envelop proteins of HIV
- or by LPS translocating in the gut after CD4 T cell death
Detecting HIV RNA, DNA and protein are
are not very sensitive ways of detecting virus - lots of false positives
Best method of detection of HIV
ELISA - 99.5% sensitive
1-2% false positive rate
To eliminate/check the 1-2% false positive
A western blot is performed for gp120/160 and gp41 proteins
gp24 at later infection stages
How soon can you detect HIV RNA?
12 days of infection
HIV p24 is detected how soon after infection
16 days
Antibody needs how many weeks to be detected
4-6 weeks
HIV viral load and disease progression are
highly correlated
The higher the CD4 count
longer survival
