Cancer Immunology Flashcards
Penetrance of tumors by T cells. . .
. . . improves prognosis
Adoptive transfer of T cells in mouse tumor models
neoantigens
The result of self proteins that are mutated as either a driver or passenger mutation in cancer. These are a potential source of foreigness signal in tumors.
Malignant tumors often _____ express _____ antigens.
Malignant tumors often abnormally express normal antigens.
This may lead to failure of tolerance against these antigens, provoking an immune response against the tumor, but also presenting the possibility of autoimmunity.
Oncogenic viral antigens
Some cancers are the result of viral activity, and so targeting immunity against the virus is synonymous with targeting immunity against the cancer.
Cancer-germline/cancer testis antigens
- Normally expressed only in testis, fetal ovaries, and trophoblasts
- Frequently expressed in cancer cells
- Not responsible for malignant phenotype
HER2/neu
- An epidermal growth factor receptor (EGFR) family receptor
- Overexpressed due to gene amplification in some breast cancers
- Contributes to malignant phenotype
prostate specific antigen
or PSA
expressed by normal and malignant prostate epithelial cells
Tissue differentiation antigen
tyrosinase
expressed by normal and malignant melanocytes
Tissue differentiation antigen
CD19
expressed by normal and malignant B lymphocytes
Tissue differentiation antigen
Derepression expression antigens
____ may overcome self tolerance, leading to killing of tumor cells.
Aberrant, uncontrolled overexpression may overcome self tolerance, leading to killing of tumor cells.
Mechanisms of tumor immunity
Which Immune Mechanisms are used to reject tumors?
- CD8+ CTL mediated killing-antigen specific (most and best evidence)
- CD4+ Th mediated help for CD8 T cells, classical macrophage activation.
- Th1 cells appear to be bad for the tumor; (Th2 responses are bad for the patient)
- Classical activation/M1 phenotype bad for tumor (alternative activation/M2 phenotype bad for patient)
- NK cell mediated killing
- Antibody mediated killing (opsonization and complement, ADCC)
- Not much evidence that endogenous antibody responses are effective
Tumor evasion of CTL immunity