HIV

Question 1

Name 5 ways HiV can be transmitted

Answer 1

Sexually
Mechanically via blood

Placental
Perinatal
Post natal

Question 2

Which virus is hiv closely related to and what does this virus infect

Answer 2

SIV

Affects chimpanzees or sooty mangabey

Question 3

Which hiv strain is chimpanzee siv homolog to

Answer 3

Hiv 1

Question 4

Which kind of things in a population made it rise in USA

Answer 4

Gay population
Sex workers
Needle transfer
Other stis

Question 5

What type of illnesses can hiv cause

Answer 5

Dementia

Immunodeficiency

Question 6

Which 2 enzymes does virus encode for which are in their nucleocapsid

Answer 6

Reverse transcriptase

Integrate

Question 7

Why is RT needed

Answer 7

Because hiv is a diploid rna + virus

Sense strand needs RT to make cDNA first

Question 8

What is the capsid protein on hiv called

Answer 8

P24

Question 9

What is the matrix protein called which packages nucleocapsid

Answer 9

P17

Question 10

Is hiv enveloped like influenza?

Answer 10

Yes

Question 11

Which 2 gp are on surface

Answer 11

120 and 41

Question 12

How does hiv enter

Answer 12

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

Question 13

When the envelope fuses with cell membrane what happens

Answer 13

Nucleocapsid is released and intregrase, rt and the diploid rna + released

Question 14

What’s the first thing which happens to the rna +

Answer 14

It is converted to cDNA -

The rna strand is then disposed of

Question 15

Which enzyme degrades rna strand after it’s been converted to cDNA

Answer 15

Rnase H (type of reverse transcriptase)

Question 16

What happens with the cDNA - strand

Answer 16

Replicated via dna dep rna polymerase

Question 17

When viral dna is ds what is the site called where it is integrated into host dna (via integrase)

Answer 17

LTRs

Question 18

What are the 3 poly proteins translated via viral dna into mrna after integration

Answer 18

Gag , pol , env

Question 19

Which 2 proteins does poly protein gag contain

Answer 19

P24 capsid protein

P17 matrix protein

Question 20

Which proteins does poly protein pol form

Answer 20

RT and integrase

Question 21

What proteins are made via polyprotein env

Answer 21

Gp 120 and 41

Question 22

When CD4 is activated by antigens what 3 things does it activate

Answer 22

CD8 cytotoxic T cells

B cells to produce antibodies

Nfkb

Question 23

What does nfkb do

Answer 23

Activates viral dna transcription into mrna

Question 24

What happens once nfkb allows transcription into viral mrna

Answer 24

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

Question 25

What happens in aids (later development)

Answer 25

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

Question 26

Why don’t vaccines work as well as education does

Answer 26

Because high level of antigenic drift

Question 27

Why won’t subcutaneous injections work

Answer 27

They increase igG levels but there is still poor mucosal protection

Question 28

Triple therapy is 3 drugs given to help prolong life, name 2 types

Answer 28

Nucleoside analogues

Peptide analogues

Question 29

What do nucleoside analogues do

Answer 29

Inhibit RT

Question 30

What do peptide analogues do

Answer 30

Inhibit protease needed to cleave the 3 poly proteins gag pol env