Antiviral Defence Mechanism

Question 1

What are virus resistance mechanism?

Answer 1

Prevent adsorption 
Prevent DNA entry 
Lyse viral nucleic acids 
Abortive infection 
Crisper-Cas

Question 2

How can you prevent virus adsorption?

Answer 2

By mutation of host receptors, but phages can mutate to bind other receptors. Host can also produce an Extracellualr polysaccharides that prevent getting close enough to bind.

Question 3

How can cells prevent Viral DNA entry?

Answer 3

If you have a temperate phage in the genome already they can do superinfection exclusion- use 2 proteins Sp And Imm. Sp blocks T4 lysozyme and Imm redirects DNA.

Question 4

How do cells break down viral nucleic DNA?

Answer 4

Use restriction enzymes to break down unmethylated DNA. Virus can then adopt to modify there DNA nucleotides

Question 5

What are the two mechanisms of abortive infection?

Answer 5

Membrane puncturing and self toxification

Question 6

What is the membrane puncturing abortive mechanism?

Answer 6

Phage DNA detected by RexA which then activates. RexA conformation becomes complimentary to RexB. Allows the escape of ions lowering potential of cell until death

Question 7

What is the self toxification mechanism?

Answer 7

Toxin/antitoxin balance is altered by the virus leading to high levels of toxin which leads to cell death