Immuno 18 Flashcards
What are proto-oncogenes?
Genes that normally contribute positively to initiation and execution of cell division
What are oncogenes?
Mutant forms of proto-oncogenes that contribute to malignant transformation
What two types of cells, if mutated, can cause malignant transformation?
Proto-oncogenes
Tumor Suppressor Genes
How many mutations are required for a cell to become a cancer cell?
5-6 different mutations
What are human oncoviruses?
viruses that infect cells and begin to express virally encoded proteins that can over-ride the cell’s normal mechanisms for regulating cell division
Are most cancers eliminated from the body?
No, probably due to inability to recognize the tumor cells as non-self.
Are most tumor antigens bound by MHC I or II?
MHC I
What is a common defect in tumor cells that allow them to survive?
A mutation in one or more HLA molecules (MHC I molecules)
What can tumor cells evade if they don’t produce MHC class I?
They cannot be recognized by CTLs.
What can still kill tumor cells if they don’t express MHC I mculs?
NK cells can still kill a tumor cell without MHC class I, but the cell must be devoid of both Class I alleles.
What is a zone of immunosuppression?
The ZOI is around the borders of a tumor, where the tumor creates cytokines that suppress or mis-direct immune responses
How can one use monoclonal antibodies?
Once a specific antigen on the tumor has been identified, mAbs can be used to detect and target tumor cells for destruction. If the mAb is bound to a toxin, the tumor can be poisoned from the inside. Also, can be attached to radionuclide.
How can T cells be used in cancer treatment?
By isolating T cells and growing them in cultures in lab, they can be reinjected into patient.
