Lecture 18: Tumor Immunology Flashcards
Diverse collection of diseases that result from abnormal and invasive cell proliferation
cancer
Why does the immune system fail to see cancer cells as “foreign”?
very similar to normal cells
“Swelling”
tumor
Tissue containing abnormally multiplying cells
tumor
Metastasis
spreading of tumor cells through lymph or blood
Carcinomas involve
epithelial cells
Sarcomas involve
non-epithelial cells
Leukemias involve
circulating cells
Lymphomas involve
solid lymphoid tumors
Myelomas involve
bone marrow
Where do melanomas occur?
Skin
Where do lymphomas occur?
lymph nodes
Where does leukemia occur?
Bone marrow
What mutagens are especially associated with cancer?
chemicals, radiation, viruses
A mutagenic agent causes:
increased mutation rate
How do tumor specific antigens play a role in tumor cell elimination?
CTLs can recognize these and kill the tumor cell
What happens when a mutated protein is presented on an MHC I?
Since it is no longer a “self” determinant, it can be recognized by a CD8
What are 3 types of tumor associated antigens?
1) Proteins resulting from reactivated embryonic genes
2) Proteins resulting from mutations
3) Overexpressed self proteins (whose density results in naive T cell recognition)
How are tumors able to evade immune responses?
Mutations, which are selected for when they are no longer recognized pre-formed immune responses
What cells are involved in tumor immunity?
CTLs and NK
Why is it significant that up to half of human tumors have defects in expression in 1 or more HLA class I allotypes?
CTLs will be unable to recognize the cells
How can a tumor suppress its environment?
Produce cytokines (such as TGF-beta)
How is an antibody humanized, why?
Add human heavy chains so the antibody can be recognized by human Fc receptors
What are 2 function of humanized monoclonal antibodies?
diagnostics or treatment
