Tumor Immunology

Question 1

tumor immunology

Answer 1

study of the antigens of tumor cells and the immune response against those antigens

Question 2

immune surveillance

Answer 2

• anti-neoplastic function of the immune system
• constantly monitoring
• part of normal function
• increasing DNA mutations alter expressed proteins
• eventually viewed as non-self by the immune system
• may be subject to attack

Question 3

tumor cell markers

Answer 3

characteristic substances produced by cancer cells:

• hormones: catecholamines
• enzymes
• genes
• antigens
• antibodies

Question 4

tumor cell markers are used to: _____

Answer 4

• screen and identify individuals at high risk for cancer
• diagnose specific types of tumors
• observe clinical course of cancer (can monitor concentrations over time)

Question 5

Tumor Specific Antigens (TSA)

Answer 5

• antigens that are only associated with tumor cells
• if present, cancer is indicated
• point mutations: changes produce catalogued abnormal proteins
• viral antigens
• cancer-germline gene products: proteins associated with sperm development

Question 6

Tumor Associated Antigens

Answer 6

• not specific to a particular tumor
• if they’re present, doesn’t necessarily indicate cancer
• normal proteins with increased expression
• proteins with altered structure: changes produce uncatalogued proteins
• oncofetal antigens: antigens normally only produced during fetal development and then silenced after birth
• differentiation antigens: antigens associated with specific tissue types

Question 7

Human Chorionic Gonadotropin (HCG)

Answer 7

• produced in high levels during pregnancy, but not produced when not pregnant
• associated with ovarian and testicular cancer

Question 8

Alpha Fetoprotein (AFP)

Answer 8

• liver cancer

- oncofetal antigen

Question 9

Carcinoembryonic Antigen (CEA)

Answer 9

• colon cancer, breast cancer

- oncofetal antigen

Question 10

Prostate Specific Antigen (PSA)

Answer 10

-increased expression in prostate cancer

Question 11

primary immunologic response to tumors

Answer 11

T-cell-mediated cytotoxicity

Question 12

immunologic responses to tumors

Answer 12

• T-cell-mediated cytotoxicity
• NK cell-mediated cytotoxicity
• macrophage-mediated cytotoxicity
• complement-mediated cytotoxicity
• antibody dependent cell-mediated cytotoxicity (ADCC)

Question 13

immune evasion

Answer 13

when the cancer cell has changed so much that cytotoxic T cells can no longer recognize it

Question 14

immune evasion mechanisms

Answer 14

• antigenic changes (low immunogenicity, antigen masking, antigen modulation, antigen release)
• immunosuppression
• speed of growth

Question 15

low immunogenicity

Answer 15

• down regulation of MHC I molecules

- pull in surface molecules that are targets for immune attack

Question 16

antigen masking

Answer 16

-cell secretes coat that covers surface that blocks other cells from physically interacting with it

Question 17

antigen modulation

Answer 17

-if an antigen is recognized, the cell will downregulate that particular antigen and upregulate another antigen

Question 18

antigen release

Answer 18

can throw off antigens and increasing concentration of antigens can block immune cells from finding actual cell that it needs to attack

Question 19

immunosuppression

Answer 19

the cell releasing cytokines that induce suppression of T-cells