Tumor Immunology Flashcards
tumor antigens
mutated protein normal cells do NOT express these antigens not available during neg. selection: loaded onto MHC class I and presented to CTLs
tumor-associated antigens
un-mutated protein that is encoded in germ-line DNA of a cell whose level of expression has been dramatically altered by a neoplastic event
1. embryonic cells not available in T cell development
MHC class I presents to T cells
2. increased expression of normal self protein
increased density can lead to recognition by effector CTLs
proto-oncogenes
when mutated and activated: transform normal cell into a tumor cell
tumor suppressor genes
gene that encodes a protein that exerts control on cell growth rates
oncogenic viruses
express antigens that can serve as tumor antigens
Adaptations of tumors that enable them to avoid immune detection or effector function
- down-regulation of MHC class I
2. down regulation of T cell activation or effector function: expression of CTLA-4, TGF-beta, Fas-ligand, or PDL-1
bispecific Ab
recombinant with two arms
1. specific for CD3
2. specific for tumor antigen
recruits CD8 T cells to tumor
NOT a specific antigen activation: any T cell can be recruited
close contact causes degranulation rather than MHC and B7
CAR
chimeric antigen receptor
CTL with B cell receptor (heavy, light, and CD3 zeta chain)
CD3 zeta chain: causes intracellular signaling ot occur
carcinoma
cancer of epithelial cells
sarcoma
cancer of CT or non epithelial cells
leukemia
cancer of circulating cells of immune system
lymphomas
cancer of immune system involving solid lymphoid tumors
myelomas
cancer of immune system involving bone marrow
What is the effector mechanism our immune system sometimes has against tumor cells?
CTL
syngenic tumor transplantation
can transfer tumor from one mouse to another if they have matching MHC haplotypes
proves CTL resonse
allogenic tumor transplantation
can NOT transfer tumor between mice with mismatching MHC haplotypes
proves CTL response