cancer

Question 1

how does the immune system detect cancerous cells?

Answer 1

tumour specific antigens, tumour associated antigens, viral antigens

Question 2

can there be vaccines against cancer?

Answer 2

yes, if the cancer is caused by a virus
e.g. HPV type 16 causing cervical carcinoma, E6 and E7 proteins

Question 3

important cytokines in tumour elimination

Answer 3

released by CTL
IFN-gamma: enhances MHC-I expression, activates macrophages and inhibits tumour proliferation

TNF-alpha: promotes inflammation, can induce apoptosis and recruits immune cells

Question 4

important cytokines + cells for tumour equilibrium

Answer 4

IFN-gamma
IL-12: can activate NK cells, suppress tumour growth and tumour blood vessel growth
NK and T cells

Question 5

how do tumour cells escape

Answer 5

no longer recognisable, no longer effective or cause immunosuppression

Question 6

HLA-I tumour expression

Answer 6

cancer cells accumulate mutations in HLA-I and beta2m, which forms the MHC molecule

Question 7

how do T cells gain tolerance to cancer cells

Answer 7

cancer cells can modulate DCs to reduce co-expression

Question 8

how do tumours create an immuno-suppressive environment

Answer 8

cytokines: TGF-Beta and IL-10 that suppress immune response and recruit Tregs
enzymes: IDO that catabolizes tryptophan (needed by T cells)
cell surface proteins: e.g. PD-L1

Question 9

tumour cells making barriers

Answer 9

Literally make a barrier with stromal cells, epithelial cells and vascular cells

Question 10

what other cells play a role

Answer 10

Trm associated with regulated melanoma, gamma-delta t cells ranked favourable