title: 3T3 fibroblasts release a low-molecular-weight inhibitory peptide of lymphocyte DNA synthesis into serum-free culture medium.
abstract: 3T3 fibroblasts release a novel factor into serum-free culture medium, which strongly suppressed concanavalin A-induced thymocyte DNA synthesis. This activity was highly purified by gel filtration, ion exchange and thin-layer chromatography and was characterized as a 1 kDa heat-stable peptide. Although this peptide suppressed lymphocyte DNA synthesis when added relatively early after lectin-stimulation, the cell viability was not changed significantly. The peptide considerably repressed DNA synthesis of some mammalian fibroblast cells, but malignant-transformed cells were not affected.
mesh_terms: D000818:Animals; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D002855:Chromatography, Thin Layer; D003208:Concanavalin A / Q000494:pharmacology; D004261:DNA Replication / Q000187:drug effects*; D005347:Fibroblasts / Q000378:metabolism*; D008214:Lymphocytes / Q000187:drug effects / Q000378:metabolism*; D051379:Mice; D010455:Peptides / Q000494:pharmacology*
chemical_list: D010455:Peptides; D003208:Concanavalin A