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29 Cards in this Set
- Front
- Back
What are genetic changes associated with neoplastic transformation lead to tumor immunity?
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Genetic alteration may result in expression of proteins seen as non-self by the immune system, not usually expressed or over-expressed in tumors.
Immune Surveillance refers to recognition and destruction of non-self tumor cells. Many tumors are eliminated, but some escape policing. |
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Which tumor antigens are present only on tumor cells and not on normal cells?
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Tumor-Specific Antigens
Mutated RAS & TP53 |
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Which tumor antigens are present on tumor cells and some normal cells?
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Tumor-Associated Antigens
MART-1 (Melanoma Antigen Recognized by T cells) |
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What recognizes polypeptide antigens presented on cell surface by MHC class I molecules?
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CD8+ CTLs
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Which tumor antigen is an Overexpression of normal antigens?
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HER-2
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Which tumor antigen is Altered mucins that can act as tumor-specific antigens?
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MUC-1
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Which tumor antigen is an Oncofetal antigen or embryonic antigen normally present during embryogenesis but not in normal adult tissue?
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CEA and alpha-fetoprotein
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Which tumor antigen is a Differentiation-specific antigen that are expressed on normal and transformed cells act as a marker for the type of cells in a tumor?
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PSA
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What are some categories of Tumor Antigens?
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1. Overexpression of normal antigens
2. Antigens from oncogenic Viruses 3. Altered mucins act as Tumor-specific Antigens 4. Oncofetal antigens 5. Differentiation specific antigens |
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What reacts to tumor antigens, such as
1. products of mutated oncogenes and tumor suppressor genes 2. products of other mutated genes 3. overexpressed or aberrantly expressed cellular proteins 4. tumor antigens produced by oncogenic viruses 5. alterered cell-surface glycolipids and glycoproteins |
CTLs
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The tumor antigens discovered in transplanted carcinogen-induced tumors in animals called _______________, are mutants of various host cellular proteins that are processed and presented in the form of peptide class I MHC complexes capable of stimulating CTLs.
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TSTA Tumor-Specific Transplantation Antigens
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T/F
Any product of a mutated gene is a potential tumor antigen |
True
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Which antigens are extremely diverse because the carcinogens may randomly mutagenize virtually any host gene and the class I MHC antigen presenting pathway can display peptides from any mutated cytosolic protein in each tumor?
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TSTA
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How could a tyrosinase vaccine treat melanomas?
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T cells from melanoma patients recognize peptides derived from tyrosinase
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What are the most potent Tumor antigen produced by oncogenic viruses?
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HPV and EBV
most potent are produced by latent DNA viruses |
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What antigens are proteins expressed at high levels on cancer cells and in normal developing (fetal) tissues but not adult tissues?
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Oncofetal antigens
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What are the two most thoroughly characterized oncofetal antigens?
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CEA Carcinoembryonic antigen
AFP Alpha-fetoprotein |
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What tumor antigen is expressed mainly by colorectal and pancreatic cancers and by cancers of the breast, ovary or lung?
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CEA Carcinoembryonic antigen
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Which tumor antigen is expressed especially in tumors of the testicles, ovaries, stomach, pancreas or liver. High levels of this tumor antigen may also be found in Hodgkin disease, non-Hodgkin lymphoma, brain tumors and renal cell cancer?
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AFP Alpha-fetoprotein
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What is the principal mechanism of tumor immunity killing of tumor cells?
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Killing of tumor cells by CD8+ CTLs
(CTLs NKCs Macrophages Antibodies) |
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What plays a protective role against virus-associated neoplasms like EBV-induced Burkitt lymphoma and HPV-induced tumors?
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Cytotoxic T Lymphocytes
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What are capable of destroying tumor cells without prior sensitization?
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NK cells
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What plays an important role when tumors down-regulate expression of cless I MHC molecules as a way of evading immunity?
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NK cells
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What cytokine activates NK cells to lyse a wide variety of human tumors in vitro?
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IL-2 activation of NK cells
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What cytokine produced by T cells and NK cells activated Macrophages?
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IFN-gamma activates Macrophages
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How do macrophages kill tumors?
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Production of reactive oxygen metabolites
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How do antibodies kill tumor cells?
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By activating complement or by antibody-dependent cell-mediated cytotoxicity, in whihc Fc receptor-bearing macrophages or NK cells mediate the killing
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What are molecules, expressed by tumors, normally present on the cells of origin called?
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Differentiation antigens
because they are specific for particular lineages or differentition stages of various cell types |
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What surface marker from specific differentiation antigens is used for identifying lymphoma as a B cell tumor?
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CD10
common acute lympoblastic leukemia antigen & CD20 |