[Antitumor action of interleukin 2 and its biological activities].

Recombinant IL-2 manifests both proliferation and differentiation-inducing activities in such a way as to generate secondary cytotoxic T lymphocytes (CTL) from memory CTL. IL-2 actually shows antitumor effects against syngeneic tumors, while the combination of IL-2 with chemotherapeutic agents clearly demonstrates complete regression of syngeneic tumors. In addition, the antitumor immunotherapeutic drug lentinan, augments the reactivities of pre-effector cells to IL-2, resulting in the efficient induction of antitumor effectors, CTL, NK and LAK. Combination therapy with lentinan, cyclophosphamide and IL-2 may well be documented as a new rational chemo-immunotherapy in place of adoptive LAK therapy and the infusion of large amounts of IL-2 causing frequent detrimental side effects.