Transplant immunity to polyoma virus-induced tumor cells. IV. A polyoma strain defective in transplant antigen induction

Differences in the capacity of polyoma virus strains to stimulate transplant resistance in hamsters as well as induce measurable quantities of the polyoma-specific transplant antigen in tumor cells were demonstrated. The large (Ip-D) and small plaque (sp-D) virus strains isolated by Dulbecco from the LID-1 polyoma virus isolated at the National Institute of Allergy and Infectious Diseases, were found to be defective in their capacity to stimulate transplant immunity against tumor cell lines known to contain the polyoma transplant antigen which had been induced by several other strains. Furthermore, both strains were defective in the quantity of transplant antigen induced in tumor cells. There was no correlation between the lack of transplant antigen activity and the neoplastic characteristics of the tumor cells induced by these virus strains; this finding suggests that the cell membrane alteration responsible for the transplant antigen function does not play a direct, mediating role in the neonlastic event.