Cancer Defences **

Question 1

Describe the cancer-immunity cycle.

Answer 1

• Release of cancer cell antigens from cancer cell death
• Cancer antigen presentation
• Activation by APCs and T cells
• Trafficking of cells to tumors
• Infiltration of T cells into tumours
• Recognition of cancer cells by T cells
• Cancer cell death

Question 2

Describe the innate and adaptive immune responses to cancer.

Answer 2

• INNATE - identifies and attacks tumor cells without antigen specificity. EXAMPLE - NK cells
• ADAPTIVE - Response - attacks tumor antigens. Sustained through memory. EXAMPLE - Cytotoxic T cells
• Regulated by activating and inhibitory pathways

Question 3

Describe the purpose of the Killer Ig-like receptors.

Answer 3

• Surface inhibitory receptor on NK cells
• Bind to MHC Class I
• Stops NK cells killing normal cells

Question 4

Describe the PD-1 inhibitory pathway.

Answer 4

• Checkpoint receptor on cytotoxic T cells
• Downregulate T cell response, prevent autoimmunity

Question 5

Describe the GITR activating pathway.

Answer 5

• Activating receptor on surface of T cells
• Enhance cell division and anti-tumor activity