HIV Flashcards
Name 5 ways HiV can be transmitted
Sexually
Mechanically via blood
Placental
Perinatal
Post natal
Which virus is hiv closely related to and what does this virus infect
SIV
Affects chimpanzees or sooty mangabey
Which hiv strain is chimpanzee siv homolog to
Hiv 1
Which kind of things in a population made it rise in USA
Gay population
Sex workers
Needle transfer
Other stis
What type of illnesses can hiv cause
Dementia
Immunodeficiency
Which 2 enzymes does virus encode for which are in their nucleocapsid
Reverse transcriptase
Integrate
Why is RT needed
Because hiv is a diploid rna + virus
Sense strand needs RT to make cDNA first
What is the capsid protein on hiv called
P24
What is the matrix protein called which packages nucleocapsid
P17
Is hiv enveloped like influenza?
Yes
Which 2 gp are on surface
120 and 41
How does hiv enter
Gp 120 binds to CD4 receptors which cause a conformation change exposing gp 41 which then binds to ccr5 co receptor = fusion of envelope with membrane
When the envelope fuses with cell membrane what happens
Nucleocapsid is released and intregrase, rt and the diploid rna + released
What’s the first thing which happens to the rna +
It is converted to cDNA -
The rna strand is then disposed of
Which enzyme degrades rna strand after it’s been converted to cDNA
Rnase H (type of reverse transcriptase)
What happens with the cDNA - strand
Replicated via dna dep rna polymerase
When viral dna is ds what is the site called where it is integrated into host dna (via integrase)
LTRs
What are the 3 poly proteins translated via viral dna into mrna after integration
Gag , pol , env
Which 2 proteins does poly protein gag contain
P24 capsid protein
P17 matrix protein
Which proteins does poly protein pol form
RT and integrase
What proteins are made via polyprotein env
Gp 120 and 41
When CD4 is activated by antigens what 3 things does it activate
CD8 cytotoxic T cells
B cells to produce antibodies
Nfkb
What does nfkb do
Activates viral dna transcription into mrna
What happens once nfkb allows transcription into viral mrna
Structural and other proteins produced
Eg rna + for the genome , p24 capsid , p17 matrix, gp120 , 41
These assemble as usual budding from the cell when gp attach to cell membrane
What happens in aids (later development)
CD4 cell levels drop to threshold that they can’t produce the immune response anymore Eg CD8 or antibodies
This means there’s development of tumours etc causing death
Why don’t vaccines work as well as education does
Because high level of antigenic drift
Why won’t subcutaneous injections work
They increase igG levels but there is still poor mucosal protection
Triple therapy is 3 drugs given to help prolong life, name 2 types
Nucleoside analogues
Peptide analogues
What do nucleoside analogues do
Inhibit RT
What do peptide analogues do
Inhibit protease needed to cleave the 3 poly proteins gag pol env
