Immunological Response of Splenic Subcellular Fraction Obtained from Induced Yoshida Sarcoma-resistant Animals

Splenic tissues prepared from Yoshida sarcoma(YS)-resistant rats, mice and rabbits were homogenized at 4°C with 0.25M sucrose solution; these homogenates were then separated into supernatant and sediment by ultra-centrifugation at 5, 000g at low temperature (4°C). After intravenous, intraperitoneal or intramuscular injections of these subcellular fractions, YS cells (105) were inoculated into the recipients and their survival time was examined. The survival time of the recipient was longest in the group injected with the supernatant regardless of the combination of rat-strains between donor and recipient and of the route of injection. Similarly, xenogeneic supernatant from YS immune mice and rabbits produced in the recipient a response against the tumor cells. But some o f the recipients died of a hemorrhagic diathesis or jaundice. On the other hand, allogeneic and xenogeneic sediments of homogenates of immune spleen cells showed little effect on tumor inoculation. The subcellular fractions obtained from allogeneic and xenogeneic normal animals had no antitumor effect. Similarly, antiserum from xenogeneic donors showed no antitumor effect. When the 5, 000×g supernatant from immune spleen cells was stored at -20°C for 30 days, the antitumor effect was not diminished. But when it was stored at 4°C for 10 days, the effect was apparently diminished. When increased quantities of the supernatant from immune spleen cells were given to animals, the survival rate of the recipients was also increased.