Role of CTL host responses and their implication for tumorigenicity testing and the use of tumour cells as vaccine substrate.

Viral oncogenes, mutated cellular oncogenes, or other adventitious agents that might contaminate vaccine preparations on inoculation of the host will encounter a T cell-mediated immune response which will play a determining role in the progression of neoplastic events or replication of contaminating viral agents. Using SV40 T antigen tumour systems as a model we discuss the regions of the oncoprotein that have an impact on tumourigenicity and the role of CD8 T lymphocyte immune responses in eliminating potential tumour cells. In addition, we discuss measures that counteract T cell immune responses to abrogate T cell-mediated immunosurveillance.