Interferons and the antiviral response

Question 1

What is the role of ifns in the antiviral response

Answer 1

They induce a antiviral response in host cells , leading to production of ISGs that target multiple stages of the viral lifecycle

Question 2

What is the JAK-STAt pathways role in antiviral immunity

Answer 2

IFN binds to its receptor , activating the JAK-STAT pathway , which induces the transcription of ISGs

Question 3

How do virusues counteract JAK-STAT signalling

Answer 3

They evolve to inhibit JAK-STAT signalling

Question 4

Interferon stimulated genes , what is their significance

Answer 4

There are hundreds all targeting all stages of the viral lifecycle

Question 5

function of IFITM proteins in antiviral immunity

Answer 5

They restrict fusion of enveloped viruses at a early stages

Question 6

How did SARS-COV -“ adapt to bypass protective protwins

Answer 6

had evolved a novel spike cleavage site to bypass IFITM protein restriction

Question 7

How does PKR inhibit viral translation

Answer 7

PKR is activated by dsRNA , which phosphorylates elF2a , blocking translation of viral proteins

Question 8

How do viruses evade PKR mediated translation inhibition

Answer 8

by sequestering dsRNA
By mimicking substrates

Question 9

What is the viperin in replication inhibition

Answer 9

It inhibits RNA viruses by converting CTP to ddhCTP blocking viral RNA synthesis

Question 10

What other organisms have viperin homologues and what do they target

Answer 10

Bacteria have them and they have antiphage activity

Question 11

How does tetherinn inhibit viral exit

Answer 11

its a cell surface protein that blocks viral release , vpu is its antagonist