title: Role of lipids in the immune response. I. Localization to a lipid-containing fraction of the active moiety of an inhibitor (SIF) of lymphocyte proliferation.
abstract: By further study, a previously described inhibitor of lymphocyte proliferation and immunoglobulin synthesis, soluble inhibitory factor (SIF), has been shown to comprise two moieties; a nondialyzable protein, apparently inert with regard to inhibition of proliferation, and a polar lipid bound to the protein fraction, presumably by hydrophobic interaction. The lipid contained the activity responsible for inhibition of PHA-induced DNA synthesis. It was tentatively identified as a lipid with an as yet unidentified polar group, on the basis of mobility on thin layer chromatographic plates and behavior on silicic acid.
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D002457:Cell Extracts / Q000276:immunology*; D005591:Chemical Fractionation; D002850:Chromatography, Gel; D002855:Chromatography, Thin Layer; D003956:Dialysis; D006801:Humans; D007165:Immunosuppression Therapy; D008055:Lipids / Q000276:immunology*; D008213:Lymphocyte Activation; D007959:Lymphocyte Culture Test, Mixed; D012824:Silicic Acid / Q000494:pharmacology; D012995:Solubility; D014020:Tissue Extracts / Q000276:immunology*
chemical_list: D000596:Amino Acids; D002457:Cell Extracts; D008055:Lipids; D014020:Tissue Extracts; D012824:Silicic Acid