Adoptive transfer of immunity by spleen cells from LSA-lymphoma mice cured by BCNU.

BCNU treatment of advanced LSA lymphoma, a poorly antigenic tumor of syngeneic C57BL/ym mice, produced large numbers of cured mice which were highly immune against further LSA tumor challenges. Spleen cells from cured mice were transferred into normal naive mice in close temporal relationship to the injection of 10(3) LSA cells and showed that during a period of two days before to one day after tumor injection, the MST and per cent tumor takes could be greatly modified. Activity was only weakly present in bone marrow or thymus cells but mixtures of these cells with or without added spleen cells were effective. In 400 rad sublethally irradiated mice it was also found that transferred spleen cells prevented progression of tumor, and resistance was permanent. This indicates that all elements of tumor recognition, affector and effector limbs of immune response were present in the adoptively transferred spleen cell population.