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23 Cards in this Set
- Front
- Back
- 3rd side (hint)
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what is produced by tumors to instigate an immune response?
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non-self antigens produced by genetically altered tumor cells
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If the immune system is flagged early on of carcinogenesis, tumorogenesis taking place the cancer can be eliminated. What is this called?
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immune surveillance
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what are 2 common tumor antigens expressed?
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TP53 = 50% human cancers
RAS = 20-30% human cancers |
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what type of lymphocytes recognize the tumor antigens via MHC class I?
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CD8+ Tcells
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Types of antigens that are recognized:
- overexpression of normal antigen __? -oncogenic viral antigens like ____? -MUC-1 = _____ antigen - _______ expressed during fetal development and no later (CEA, alpha-fetoprotein) |
1) HER-2
2) HPV 3) altered mucins 4) Oncofetal antigens |
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what characteristic of tumor cells results in many different genes being mutated that are not directly associated with problematic mutations?
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genetic instability
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what of the following produce the most tumor antigens in frequency?
1) radiation-induced 2) inspontaneous human cancers 3) chemically-induced |
chemically / radiation induced - b/c both transform many genes
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besides CD8+ Tcells recognizing MHC class I tumor antigens, what is another means of recognition?
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CD4+ Tcells recognizing via MHC II pathway that present dead tumor antigens
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TSTA are _____ that are involved in the MHC I presentation to CTLs.
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tumor-specific transplantation antigens
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what is an example of Overexpressed cellular proteins leading to tumors and recognized as a tumor antigen (peptides of this protein) involved in melanomas?
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tyrosinase
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what are 2 examples of oncgogenic viruses that produce tumor antigens?
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HPV
EBV --> lymphomas (burkitt's) |
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oncofetal antigens are expressed on what 2 tissue types?
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1) normal fetal tissue
2) cancer cells |
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what are 2 common oncofetal antigens?
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CEA ( carcinoembryonic antigen)
AFP ( alpha-feto protein) |
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which of the 2 oncofetal antigens is expressed by the following cancers:
-colorectal -pancreatic -breast -ovary -lung |
CEA
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which of the 2 oncogenic fetal antigens is expressed most in the following cancers:
-testicles -ovaries -stomach -pancreas -liver -Hodgkin/non-' '/brain tumor, renal cell cancer |
AFP
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the PRINICIPAL mechanism of tumor-killing are what type of cells?
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CD8+ CTLs
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apart from CTLs what are the other cells that cooperate in fighting tumor cells?
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1) NK cells
2) Macrophages 3) Antibodies |
3
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why are NK lymphocytes particularly effective in killing tumor cells by lysing?
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tumor cells that downregulate MHC 1 expression for the sake of evasion are still ID and killed by NK cells
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macrophages play a role in tumor killing when recruited by ____ cells by the cytokine ______
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NK cells
T cells by IFN |
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is there evidence of humoral immunity versus tumors?
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no
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antibodies may kill tumors via 2 mechanisms:
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1) complement activation
2) antibody-dependent cell-mediated (NK cells) |
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what type of antigens are utilized in discovering the origin of the tumor tissue
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differentiation antigens
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what are 3 mechanism that tumors evade immune attack?
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1) failure of tumor to produce an antigen
2) mutations in MHC gene or those necessary for presentation/recognition 3) production of immunosuppresive proteins by tumor (TGF-beta) |
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