Question

Scenario 2.
Normally viruses infect a host cell, replicate themselves inside it and burst the host cell so that they can go on infecting other cells. In this viral infection, the virus has stopped the normal apoptotic pathway to allow themselves to stay within the cell indefinitely – a phenomenon known as latency. Further studies on this virus has shown that the virus encodes inhibitors of caspase 8 activation.

Scenario 2 describes the development and maintenance of a latent viral infection, allowing the virus to persist in the host cell. If we assume that the infection has already developed latency in the patient (i.e. the person is already infected and the virus is persisting in the cell), which of the following methods would be the MOST APPROPRIATE method to eradicate the virus from the host cell and stop the latent infection?

Select one:
a. Develop a vaccine against the virus, which enhances apoptosis via the intrinsic pathway
b. Block viruses from inserting their nucleic acids into a host cell
c. Upregulate the expression of DISC assembly proteins
d. Promote the release of cytochrome C in all cells

Scenario 3. Parkinson’s disease is a chronic neurodegenerative disorder characterised by uncontrollable tremors and muscle rigidity. Studies have linked Parkinsons disease with mutations in several different genes, one of which is PINK1. Studies have shown that in PINK1 deficient human and mouse neurons there was an increase in cytochrome C release from the mitochondrion.

Scenario 3 describes the development of Parkinson's disease in neurons due to the accumulation of mutations in PINK1 (as well as other genes). Based on your knowledge of cell death, the function of PINK1 is most similar to that of...?

Select one:

a. Puma

b. Bcl-2

c. IAPs

d. p53

e. Bak

Answer 1

a. Develop a vaccine against the virus, which enhances apoptosis via the intrinsic pathway

The intrinsic pathway mainly triggers apoptosis in response to internal stimuli: A vaccine can eradicate virus-infected cells through the use of apoptosis.

Cytochrome c is also involved in the initiation of apoptosis. Upon the release of cytochrome c to the cytoplasm, the protein binds apoptotic protease activating factor-1 (Apaf-1). Apoptotic protease activating factor 1, also known as APAF1, So cytochrome c, would not be an option as cytochrome c activates caspases and if the virus inhibits it then initiating the release of cytochrome C in all cells won't` help.

b. Bcl-2

The PINK1 gene provides instructions for making a protein called PTEN induced putative kinase 1.

During transduction of an apoptotic (death) signal into the cell, there is an alteration in the permeability of the membranes of the cell's mitochondria, which causes the translocation of the apoptogenic protein cytochrome c into the cytoplasm, which in turn activates death-driving proteolytic proteins known as caspases. Bcl-2 is proposed to inhibit the activity of presumptive CED-4-like adaptors for at least two upstream initiator caspases.