title: Requirements for induction of specific suppressor T cells and detection of their H-2 antigen-binding receptors by fractionation on target cell monolayers.
abstract: The MC-resistant specific suppressor T cells that inhibit DNA synthesis and CTL generation in MLC were induced in vivo by gamma-irradiated allogeneic lymphoid cells in a large dose. MLRs were inhibited only slightly when triggered by third-party cells, even neighbouring with the corresponding stimulators. Unlike the irradiated cells, intact allogeneic lymphoid cells induced a mixture of macrophage-like and T-cell suppressors with a pronounced non-specific component of the action. Syngeneic cells induced low active non-specific suppressors of macrophage type only. The suppression was not due to a cytotoxic effect, since specific T suppressors differed from CTL by conditions of induction and high sensitivity to gamma-irradiation and from CTL precursors by high sensitivity to CY and HC. The specific T-suppressors could be selectively removed by adherence to a macrophage monolayer of the corresponding donor. The subsequent elution of adherent lymphocytes with pronase resulted in enrichment of specific T suppressors by a factor of 30 and 2.6, as judged by reduction in the number of lymphocytes required for 50% inhibition of DNA synthesis and 33% inhibition of CTL generation, respectively. The high specificity of this enrichment is shown by using both syngeneic monolayers for fractionation and third-party stimulators in MLR for testing and by disappearance of slight non-specific suppression caused by non-fractionated suppression. Complete inactivation of the eluted suppressors with anti-Thy-1.2 and anti-T antibodies, their resistance to anti-Mls antibodies, carrageenin, and carbonyl iron, together with the data of autoradiographic study and total DNA synthesis in the population indicate that the eluted highly specific suppressors represent mainly DNA-synthesizing large and medium T lymphocytes.
mesh_terms: D000818:Animals; D001345:Autoradiography; D002458:Cell Fractionation; D005591:Chemical Fractionation; D003601:Cytotoxicity Tests, Immunologic; D004247:DNA / Q000096:biosynthesis; D000939:Epitopes; D006183:H-2 Antigens; D017708:Leukocyte Transfusion; D008213:Lymphocyte Activation; D007959:Lymphocyte Culture Test, Mixed; D008264:Macrophages / Q000276:immunology; D051379:Mice; D008815:Mice, Inbred Strains; D009374:Neoplasms, Experimental / Q000276:immunology; D013154:Spleen / Q000528:radiation effects; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*
chemical_list: D000939:Epitopes; D006183:H-2 Antigens; D004247:DNA