Question

Q2. A virus must replicate in the infected cell and orchestrate the assembly of virion constituents to produce progeny viruses and propagate itself. This often happens at the expense of the infected cell. A radical but ultimately effective response to stop virus replication is for the infected cell to self-destruct via apoptosis. Some viruses have evolved strategies to overcome this.

A. Some Coronoviruses does it by inducing apoptosis of the killer lymphocyte cells. How does apoptosis of killer lymphocyte cells prevent apoptosis of the host cell? (10 points)

B. Some viruses prevent apoptosis of the host cell by coding for proteins that directly interfere with the host cell proteins. Discuss possible host cell proteins that may be targeted by such virus proteins that prevent apoptosis. (8 points)

Answer 1

A.The killer lymphocyte releases two products like perforins and granzymes.Perforins make the holes in the membrane whereas granzymes activates the caspases which trigger apoptosis.If the virus makes the killer lymphocyte undergo apoptosis there will be no release of perfoins and granzymes and the host cell do not undergo apoptosis.

B.The host cell proteins that are targeted are caspases which are involved in the apoptosis of the infected cells.They interfere with the caspases proteins and thus prevents apoptosis of infected cells.