title: Synergistic cytotoxicity. II. In vitro arming of monocytes and T cells by a heat labile fraction of human plasma.
abstract: In a previous paper we demonstrated that freshly obtained human plasma contain a heat labile nonantibody factor that induced human mononuclear cells to become nonspecifically cytotoxic toward xenogeneic but not allogeneic RBC targets. We now present evidence that this factor has a loose affinity for human monocytes and human T cells and can arm then to kill xenogeneic RBC targets. Furthermore, proteolytic enzymes markedly enhance this arming effect. This ability to be armed by a heat labile component found in fresh human plasma and the fact that proteolytic enzymes markedly enhance cytotoxicity clearly dissociate this model of nonspecific cytotoxicity for previously reported NK models.
mesh_terms: D000042:Absorption; D000818:Animals; D002469:Cell Separation; D002645:Chickens; D003602:Cytotoxicity, Immunologic; D004912:Erythrocytes / Q000276:immunology; D006358:Hot Temperature; D006801:Humans; D009000:Monocytes / Q000276:immunology*; D010447:Peptide Hydrolases / Q000494:pharmacology; D011817:Rabbits; D012397:Rosette Formation; D013601:T-Lymphocytes / Q000276:immunology*; D014357:Trypsin / Q000494:pharmacology
chemical_list: D010447:Peptide Hydrolases; D014357:Trypsin