Tumor Immunology Flashcards
What is cancer?
A diverse collection of diseases that result from abnormal and invasive cell proliferation; they are very similar to normal cells so the immune system cannot effectively “see” them as foreign
How does cancer arise?
Mutations of somatic cell DNA
What is a tumor?
Tissue in which cells are multiplying abnormally
What is metastasis?
Spreading of tumor cells through lymph or blood
What are carcinomas?
Cancers of epithelial cells
What are sarcomas?
Cancers of other cells
What are the cancers of the immune system?
Leukemias: involving circulating cells
Lymphomas: involving solid lymphoid tumors
Myelomas: involving bone marrow
Exposure to what initiates cancer?
To chemicals, radiation, and viruses; carcinogens (mutagenic agents)
HPV leads to what type of benign and metastatic cancer? (DNA Virus)
Warts (benign); Carcinoma of the uterine cervix
Hepatitis B leads to what kind of cancer? (DNA Virus)
Liver cancer (hepatocellular carcinoma)
Epstein-Barr virus (EBV) leads to what kind of cancer? (DNA Virus)
Burkitt’s lymphoma (cancer of B lymphocytes), Nasopharyngeal cancer, B-cell lymphoproliverative disease
Human T-cell leukemia virus type 1 leads to what kind of cancer? (RNA virus)
Adult T-cell leukemia/lymphoma
HIV-1 and HHV8 lead to what kind of cancer?
Kaposi’s sarcoma
Some tumors express what that can be recognized by the immune system?
Tumor specific antigens (TSA’s); different tumors express different TSA’s
Tumors arise from? 2 things
1) Reactivation of embryonic genes not normally active in the cell
2) Over-expression of normal self-proteins which changes density of self-peptide presentation leading to recognition by T-Cells
What happens if you inject tumor cells from an MHC_A mouse into an MHC_B mouse?
Tumor cells are rejected and the mouse lives
How can tumor cells evade immune responses?
They mutate so they are not recognized; between 1/3 and 1/2 have defects in expression of HLA class 1 allotropes
What cells are both involved in immunity to tumors?
CTL’s and NK cells
What do tumors produce to create an immunosuppressive environment around the cell?
Cytokines (such as TGF-beta)
Tumor targeting is done using what?
Humanized monoclonal antibodies (hmAbs)
How can humanized monoclonal antibodies be used?
Diagnostics
Treatments; hmAbs used as ligand agonists or antagonists, or conjugated to toxins or radionucleotides for targeted killing of tumor cells
What are the two ways cancer cells can be targeted?
Toxin binds and enters nucleus = apoptosis
Drugs radioactively bind to cells, radiation damages cells and kills them