Virus-Induced Transplantation Immunity to Human Adenovirus Type 12 Tumors of the Hamster and Mouse.

Adult Syrian hamsters and C3Hf/Gs mice, beyond the age of susceptibility to tumor induction, were immunized by 3 or 4 injections of human adenovirus type 12. These animals, together with equal numbers of non-immunized controls of the same species, sex, and age, were inoculated with 10-fold serial dilutions of tumor cells induced by adenovirus type 12 in newborn animals of the same species and strain. In both the hamster system and the mouse system preimmunization with virus increased the resistance to subsequent transplants of A-12 tumor cells. The resistance was relative rather than absolute. In the hamster it was overcome by a 10-fold increase in tumor cell inoculum. In the mouse system, an inoculum of 100 to 1000 or more times as many tumor cells was required to overcome the induced resistance. The hamster and mouse tumor cells used have previously been shown to be free of infectious adenovirus. Tumors induced by this human virus in these two species of rodents appear to behave similarly to tumors induced by several animal viruses in that they contain a new virus-induced transplantation antigenicity.