Evasion of immune surveillance

Question 1

Immune surveillance

Answer 1

Normal function of the immune system is to constantly scan the body for emerging malignant cells and destroy them.

Question 2

Tumor antigens

Answer 2

Antigens present on the csm of the tumor cells that elicit an immune response.

Question 3

Types of tumor antigens

Answer 3

1- Antigens produced by genes bearing driver and passenger mutations
2- Overexpressrd normal cellular proteins
3- Products of mutated onco and tumor suppressor genes
4- Tumor antigens produced by oncogenic viruses
5- Oncofetal antigens
6- Altered cell surface glycolips and glycogen proteins
7- Cell type specific differentiation antigens

Question 4

Driver mutations

Answer 4

those which confer a fitness to somatic cells in their micro environment and contribute directly to cancer progression

Question 5

Passenger mutations

Answer 5

those which do not alter fitness and do not directly contribute to the development of cancer

Question 6

Overexpressed or aberrantly expressed normal cellular proteins

Answer 6

normal cellular proteins become tumor antigens when they are overexpressed in tumor cells
eg- tyrosinase
-MAGE

Question 7

Proteins produces by mutated onco and tumor suppressor genes

Question 8

Tumor antigens produces by oncogenesic viruses

Answer 8

proteins that are produced by oncogenic viruses are recognised as foreign by the immune system
most potent viruses- HPV
-EBV

Question 9

Oncofetal antigens

Answer 9

proteins that are expressed in high levels in cancer cells and normal developing tissues
eg -carcinoembryo
-a-fetoprotein (AFP)

Question 10

Altered cell surface glycoproteins and lipids

Answer 10

tumor cells express higher than normal levels of glycoproteins and glycol lipids
eg- ganglioside
-mucins
blood group antigens

Question 11

Cell type specific differentiation antigens

Question 12

Anti tumor effector mechanism

Answer 12

Cells- CTLs
NK cells
macrophages

Question 13

Cytotoxic T-Lymphocytes