Immunization against the polyoma tumor-specific transplantation antigen (TSTA) with polyoma T-antigens. 
The relationship between the polyoma virus tumor-specific transplantation antigen (TSTA) and 2 of the virus proteins coded from the early region of polyomavirus was investigated.  Mice were immunized with small T antigen and a truncated mutant of middle T antigen, both purified from genetically engineered Escherichia coli.  The 2 proteins induced protective immunity against polyomavirus-induced tumors, but not against non-polyoma tumors, indicating that one or more of the polyoma T antigens are directly involved in a TSTA function.