title: Splenic suppressing factor: purification and characterization of a factor suppressing thymidine incorporation into activated lymphocytes.
abstract: Suppressing activity upon the mitogen-activated lymphocytes was found in the supernatant (SUP) from the culture of mouse spleen, high-density subpopulation of thymocytes, and peritoneal exudate cells. Suppressing factor was obtained from the non-stimulated lymphocytes cultured for 24 to 36 hr with or without serum. Suppressing activity in the SUP was observed in the incorporation of 3H-thymidine, 3H-uridine, and 3H-leucine into Con A-activated lymphocytes or in the proliferation of L cells. Suppressing factor partially purified by Sephadex G-25 column chromatography was a heat-stable and dialyzable substance(s). Further purification and isolation of this factor by two-dimensional thin layer chromatography revealed that this was thymidine and thymidine monophosphate. The suppression in 3H-thymidine incorporation was attributed to the dilution effect of cold thymidine released from cultured lymphocytes.
mesh_terms: D000818:Animals; D001202:Ascitic Fluid / Q000276:immunology; D002474:Cell-Free System; D002850:Chromatography, Gel; D002855:Chromatography, Thin Layer; D007166:Immunosuppressive Agents / Q000302:isolation & purification / Q000494:pharmacology*; D066298:In Vitro Techniques; D007739:L Cells / Q000378:metabolism; D007930:Leucine / Q000378:metabolism; D008198:Lymph Nodes / Q000276:immunology; D008213:Lymphocyte Activation; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D013154:Spleen / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology; D013936:Thymidine / Q000378:metabolism; D013950:Thymus Gland / Q000276:immunology; D014529:Uridine / Q000378:metabolism
chemical_list: D007166:Immunosuppressive Agents; D007930:Leucine; D013936:Thymidine; D014529:Uridine