title: Inhibition of cytotoxic T lymphocytes by a schistosome-derived inhibitory factor is independent of an inhibition of the production of interleukin 2.
abstract: Schistosome-derived inhibitory factor (SDIF) was shown to inhibit lymphocyte proliferation. While SDIF is not toxic to lymphoid cells, the generation of cytotoxic effector cells was inhibited by SDIF in a mixed lymphocyte culture. This inhibitory effect was not attributable to the induction of suppressor cells, as SDIF also inhibited the development of nonspecific suppressor cell activity in 7-day cultures of unstimulated spleen cells. The interleukine 2-dependent proliferation of cytotoxic T lymphocytes of or of blast cells was markedly reduced by the addition of SDIF. In contrast, the production of interleukine 2 itself was not impaired by SDIF. These results support the hypothesis of an inhibition by SDIF of a particular step of the mitotic cycle, probably posterior to the G0-G1 transition. An inhibitory activity of SDIF on the expression of the cytolytic activity of cytotoxic T lymphocytes was also observed.
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D007376:Interleukin-2 / Q000096:biosynthesis*; D007959:Lymphocyte Culture Test, Mixed; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D012547:Schistosoma / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology* / Q000378:metabolism
chemical_list: D007376:Interleukin-2