RESUMO
F344 inbred were repeatedly immunized (days 0, 28, and 42) with normal syngeneic or allogeneic rat tissues or transplantable syngeneic or allogeneic rat tumors (some of which were virus producing). Immunized rats were challenged by sc injection of 10(5) or 10(6) syngeneic rat tumor cells from either of two different tumor lines. Successful cross-protective immunization prevented tumor development in rats that were challenged at 100-1,000 times the 50% tumor dose. The protection was essentially lifelong and complete in that no tumors appeared up to 200 days post challenge in some experiments. To be successful, the tumor cell vaccines had to express a complement-fixing cross-reacting antigen detected with sera from rats bearing any of several different tumors and to be able to induce a spontaneously regressing tumor in the host.
Assuntos
Antígenos de Neoplasias , Imunização , Neoplasias Experimentais/imunologia , Animais , Linhagem Celular , Testes de Fixação de Complemento , Reações Cruzadas , Feminino , Rejeição de Enxerto , Imunização Secundária , Masculino , Transplante de Neoplasias , Neoplasias Experimentais/microbiologia , Ratos , Ratos Endogâmicos F344 , Retroviridae/crescimento & desenvolvimento , Fatores de Tempo , Replicação ViralRESUMO
Human cancer cells that had had high (greater than 160) tissue culture passages, when transplanted into antithymocyte-treated F344 newborn rats, caused induction of rat sarcomas in the rats within 2 or 3 subcultures, whereas human cancer cells with low (5-33) passages in vitro did not cause overt induction of rat sarcomas until after 5-10 subtransplantations. Because oncornavirus activity was not detected in either rat or human tumors, it is suggested that transforming sequences located on the human tumor cells may have been transferred to supporting rat reticulum cells in close contact with the human cancer cells.
