Restoration of immunologic memory in the tumor-bearing mouse

Using C3H/HeHa mice and a transplanted methylcholanthrene sarcoma induced in this strain, the effect of simple and radical amputation of the tumor‐bearing leg on tumor immunity was evaluated. Radical amputation of the tumor‐bearing leg removed the protective effect upon subsequent tumor challenge while immunity was present in mice submitted to only simple amputation of the tumor‐bearing leg. However, radical amputation of the contralateral normal leg resulted in failure to demonstrate protection to subsequent challenge. These data suggest that severe stress is the cause of lack of demonstrable immunity in these mice. Restoration of immunity was attempted by injecting a tumor vaccine after radical amputation. When injected immediately after the operative stress, no immunity to tumor was seen. On the other hand, if the vaccine was injected 12 days after operation, protection once again was demonstrated.