T and B cells induce macrophages which suppress proliferation but not lymphokine secretion.
In vitro culture of mouse spleen cells for 2 days or more leads to the production of adherent, phagocytic, Thy-1-, Ia+, Lyt-2- cells ("suppressor macrophages") which strongly inhibit the proliferative response of T and B lymphocytes to a variety of stimuli: mitogens, specific antigens, and antigen-nonspecific growth factors. Suppressive activity fails to develop, however, in cultured spleen cells from which nonadherent cells have been removed before the initial 48-hr incubation, and only partial suppression is obtained from cell suspensions from which T cells have been depleted before culture. We find that the requirement for nonadherent cells can be replaced by graded doses of lymphocytes. Lyt-2- and Lyt-2+ T cells are about equally potent in inducing suppressive activity in nonadherent cells. Surprisingly, B cells (containing fewer than 0.1% contaminating T cells) are also able to induce suppression in this system. The suppression induced includes both indomethacin-sensitive and indomethacin-resistant components. Interestingly, not all stages of mitogen-induced T-cell activation are blocked by these adherent cells: proliferation is inhibited, but production of interleukin 2 (IL-2) and interleukin 3 (IL-3) is unaffected.
D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D002478:Cells, Cultured; D004306:Dose-Response Relationship, Immunologic; D007108:Immune Tolerance / Q000187:drug effects; D007213:Indomethacin / Q000494:pharmacology; D008213:Lymphocyte Activation; D008222:Lymphokines / Q000378:metabolism*; D008264:Macrophages / Q000276:immunology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D013601:T-Lymphocytes / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*
D008222:Lymphokines; D007213:Indomethacin