Cancer and the Immune System Flashcards
What is oncogenesis and what factors contribute to it (4)?
The development of cancer
- Genetic Mutation
- Loss of cellular regulation
- Increased proliferation
- Reduced immune surveillance
What are tissue specific antigens?
Normal proteins found in both normal and cancer cells
What are viral antigens?
Foreign products expressed on virally infected cancer cells
What are reactivated gene products?
Proteins that normalll are not expressed after fetal development that get “turned on” by the cancer
What are mutated gene products?
abnormal proteins
Which cells are important in immune surveillance?
CTL cells (CD8 T cells), NK cells, and macrophages
What do CD8 T cells do in immune surveillance?
recognize abnormal cels through abnormal internal peptides from cancer cells presented in context of MHC I
What do NK cells do in immune surveillance?
- recognize the down regulation (absence of MHC I)
- recognize MHC related proteins that are expressed on “stressed” cells which can include cancer cells
- can bind the Fc portion of the antibody and target cancer cells
What do macrophages do in immune surveillance?
phagocytosis of dead/dying cancer cells and presentation of cancer antigens to CD4 T cells
What is KIR and what does it do?
KIR- killer inhibitory receptor
Function- binds to MHC I and “protects” cell from NK detection
What are the mainstays of anti-cancer therapeutics?
Chemo and radiotherapy
What are other immunotherapies that have been tried other than chemo and radiation?
- Non-specific stimulation
- Passive immunization
- Active immunization
- Expand immune cell population
What methods are used with active immunization?
- Chemically modified tumor cells
- DNA vaccination
- Vaccination against oncogenic viruses (Marek’s, FelV)
How do you expand an immune cell population?
Remove lymphocytes from patient
grow cells on plate for proliferation
take grown cells and place back into patient
What is expressed in nearly all melanomas?
Tyrosinase
How is immunotherapy used in B-lineage non-Hodgkin lymphoma? (what does the future hold for immunotherapy question)
- Isolate T cells from blood and expand these in culture
- standard chemo
- administer autologous T cells after chemo
- Increased tumor free survival by 9 months
What types of cells in the immune system can become neoplastic?
Any cell of the immune system
Lymphoma is the _____ common hemolymphatic malignancy of dogs and cats
Most
Lymphoma can arise from ____ lymphoid cell and usually arises from _________
any lymphoid cell
organized lymphoid tissue
What are two clinical features of plasma cell neoplasia?
- plasmacytoma (solid mass)
2. Myeloma (infiltration in bone marrow or extramedullary sites)
How is flow cytometry used?
cells are labeled with antibodies to identify their phenotype
Many of the markers are key cell receptors for differentiation or signaling
What types of neoplasia are identified best with flow cytometry?
lymphoid neoplasia
What is PARR and how is it used?
PARR- PCR for antigen rearrangement
