Studies on the polyoma-virus-induced tumor-specific transplantation antigen (TSTA)--does middle or large T-antigen play a role?

Mice and rats could be immunized against the polyoma-virus-induced tumor-specific transplantation antigen (TSTA) by repeated inoculation of frozen or irradiated cells of an MT-cDNA-transformed rat cell line (2.8) that contains only the polyoma middle T-antigen, or by cells that carried a host range mutant and expressed a full-length large T-antigen, but only non-functional N-terminal fragments of small and middle T. This shows that neither large T nor an intact middle T is necessary to elicit a polyoma tumor-specific graft rejection response. Either one of them is sufficient by itself.