Consequences Viral Infection

Question 1

What are the 8 ways a virus can modify a host cell?

Answer 1

1) subversion cellular metabolism
2) host cell stimulation
3) changes in nucleotide metabolism
4) membrane modification
5) cytopathic effect (cpe)
6) suppression host signalling pathways
7) lytic/non-lytic infection
8) cell transformation

Question 2

What is subversion?

Answer 2

Induction shut-off host protein synthesis

Question 3

How long between poliovirus infection do infected cells become subverted?

Answer 3

1 hour

Question 4

How does poliovirus prevent recognition of host mRNA by ribosomes?

Answer 4

Destroys component cap-binding complex

Question 5

In the absence of a cap-binding complex, how is the poliovirus RNA recognised and translated?

Answer 5

By internal ribosome entry site (IRES), RNA secondary structure close to 5’ end poliovirus RNA

Question 6

How do viruses modify host cell membranes?

Answer 6

Inserting their own proteins

Question 7

Which viral enzymes can be used to increase the dNTP pool?

Answer 7

Thymidine kinase
Thymidylate kinase
Rubonucleptide reductase

Question 8

How does vaccinia virus stimulate the host cell?

Answer 8

Produces its own EGF to stimulate division neighbouring cells making them ideal targets

Question 9

How may the measles virus utilise membrane modification to spread?

Answer 9

Fuse with non-infected cells causing spread without becoming extracellular, it is a cell-associated pathogen

Question 10

3 features of a transformed cell?

Answer 10

Uncontrolled growth
Contact inhibition
Properties malignant cells in vivo