HIV and AIDs Flashcards
HIV glycoprotein =
gp 120
what does gp 120 bind to
CD4 and CCR5
CD4=
T-helper cell receptor
organisation of HIV viron=
in a capsid with glycoproteins on the outside
inside HIV viron=
- 2 strands of RNA
- enzymes= Reverse transcriptase, integrase, protease
HIV co-receptors=
CCR5
CXCR4
when HIV membranes fuse with CD4 cells what happens
RNA and enzymes delivered into cytoplasm
what makes DNA copies of the RNA
Reverse transcriptase
what combines viral DNA into chromosome
Viral enzyme integrase
how long does the virus stay in the cell
life of cell
what does protease enzyme do
packages accumulated mRNA into a new virus
what is the process of DNA replication by HIV reverse transcriptase prone to
error
what can nucleotide changes cause
amino acid changes—->continuous generation of new HIV viral variants
what can a HIV infection within an individual be conceived as
a viral swarm (or quasi species)
what happens if an mutation error is advantageous
take over as the main type of swarm
what happens in primary HIV infection
massive HIV infection of memory CD4 T cells (huge CD4 cell loss in gut lymphoid tissue)
what happens in Chronic HIV infection
apoptosis/ bystander killing of uninfected CD4 cells
what induces bystander killing
viral proteins (Env, Vpr, Tat, Nef)
what pathways activate bystander killing (2)
FasL
PD-1
risk of HIV infection >500 CD4 count
minimal or none
e.g of 3 opportunistic infections possible <200 CD4
pneumocystis pneumonia
toxoplasmosis
oesophageal candida
Kaposi’s sarcoma=
- viral cancer
- caused by HHV8 herpes virus .
- proliferation of blood vessels—>purple red colour on face only
most common opportunistic infection
pneumocystis pneumonia
CNS toxoplasmosis=
affects plasma in brain —> huge abscesses
CMV retinitis=
pizza pie in retina (necrosis and bleeding)
acute onset of blindness 2-3 weeks
a pneumonia found in AID/HIV also found in premature infants
pneumocystis jiroveci
what is pneumocystis jiroveci caused by
fungi
5 classes of Antiviral drugs
NRTIs NNRTIs PIs Boosting agens CCR5 inhibitor integrase inhibitors
NRTIs=
nucleoside reverse transcriptase inhibitors
NNRTIs=
non-nucleotide reverse transcriptase inhibitors
PIs=
protease inhibitors
name 3 NRTIs
abacavir
tenofovir
lamivudine
name 4 NNRTIs
nevirapine
Efavirenz
Etravirine
Rilpivirine
name 2 protease inhibitors
Atazanavir
darunavir
3 integrase inhibitors
Raltegravir
Elvitegravir
Dolutegravir
antiviral therapy rule=
always start with 3 agents, 2 NRTIs + either; NNRTI, PI or II
after starting Antiviral therapy when should viral load become undetectable
within 6 months
what happens if the viral load rises to >500 on Antivirals
ask for sequencing/ anti-retroviral drug resistance and compare with baseline
