Viral immunity

Question 1

What are the effects of antibodies on viruses?

Answer 1

Blocks viral binding to host cells + activates TRIM21 for intracellular degradation
Antibody + complement = damage to lipid envelope and opsonisation for phagocytosis
When bound to infected cells = cytotoxicity

Question 2

Define antigenic shift and antigenic drift

Answer 2

Shift - 2 viral genomes merging to form 1 virus

Drift - Mutations over time

Question 3

What are the 4 cytokines/interferons released upon initial viral infection?

Answer 3

IFN-a, IFN-b, TNF-a and IL-12

Question 4

What is the 2nd phase of viral infection?

Answer 4

Natural killer cell mediated death of infected cells

Question 5

What is the final stage of viral infection?

Answer 5

T-cell mediated killing of infected cells

Question 6

What do interferons do?

Answer 6

Activate immune cells
Signals eighbouring infected cells to undergo apoptosis
Signals neighbouring uninfected cells to destroy RNA and reduce protein synthesis

Question 7

What happens when a cell does not express Class 1 MHCs?

Answer 7

Natural killer cell mediated cell death