Biologic activities of recombinant human interleukin 2 on murine lymphocytes

: Recombinant human IL-2, produced by yeast cells, was tested in a number of in vitro responses with murine lymphocytes. The responses studied included proliferation of a cloned murine T lymphocyte line, generation of cytotoxic responses, recall of cytotoxic memory, and restoration of responses in spleen cells taken from cyclophosphamide-treated mice. In all cases, the recombinant human IL-2 had the same activity as purified murine IL-2. The recombinant material represents a source of IL-2 free of other lymphokines. The responses described in this work can therefore be ascribed to the direct effects of human IL-2, of known sequence, on the cells of interest.