Immunology of HIV

Question 1

What is primary immunodeficiency?

Answer 1

It has a genetic basis and it relatively rare

Question 2

What is secondary immunodeficiency?

Answer 2

It is more common, caused by extrinsic factors (HIV, age, drugs, malignancy) outside the host immune system

Question 3

What type of virus is HIV?

Answer 3

Double stranded RNA virus

Question 4

What is the life cycle of HIV?

Answer 4

Binding of gp120 to CD4
viral genome enters cell
reverse transcriptase catalyses ssRNA to form RNA-DNA hybrid
ribonuclease degrades RNA to form dsDNA
dsDNA enters host genome
proviral DNA to ssRNA
ssRNA to cytoplasm
Precursor proteins synthesised
viral proteins prepared
virions bud
mature virus infects other cells

Question 5

What is the effect of HIV?

Answer 5

Abnormal and lack of immune responses because CD4 is removed from the process

Question 6

What are the 2 key chemokine receptors on T cells in HIV?

Answer 6

CXCR4 and CCR5

Question 7

What is pyroptosis?

Answer 7

Highly inflammatory form of programmed cell death

Question 8

What 2 ways does HIV kill CD4+ cells?

Answer 8

Apoptosis and pyroptosis