[Study of the action of tumor cell immunosuppressive factors on the production of cytokines by lymphocytes and macrophages and the mitogenic activity of interleukin-2].

: The effect of immunosuppressive factors (ISF) derived from tumor cell lines (mastocytoma P-815, leukosis EL-4 and melanoma B16) on the production of interleukin-1 (IL-1) by macrophages and of interleukin-2 (IL-2) by splenocytes of BALB/C mice was investigated. We could show that treatment of above cells by the tumor products resulted in strong decrease of IL-2 production but did not affect IL-1 secretion. ISF inhibited the proliferation of BALB/C lymphoblasts caused by recombinant IL-2. Thus, one of the significant mechanisms of ISF action seems to be disturbance of monolymphokine cascade of lymphocyte activation.