Prevention and Interruption of SV40 Induced Transplantation Immunity with Tumor Cell Extracts. ∗

Summary

Newborn hamsters inoculated at birth with ghosts prepared from cells transformed by papovavirus SV40 and subsequently vaccinated as weanlings with the virus, failed to reject later challenge of the autologous tumor cells. In other experiments, the establishment of transplantation immunity conferred by inoculation of the virus into normal weanling hamsters could be interrupted with tumor cell extracts injected during the course of virus immunization. Once immunity had been established, however, inoculation of ruptured tumor cells failed to significantly alter the immune status of the animals.