Identification of a human monocyte cytotoxicity-inducing factor from T cell hybridomas produced from Sezary's cells.
Sezary's syndrome is a leukemic proliferation of OKT4+ lymphocytes. Sezary cells were isolated by differential centrifugation and fused to CEM.8azar.C, and HGPRTase-lacking clone of CEM. The hybrid cells were studied for their ability to produce soluble mediators of human monocyte cytotoxicity. The product of a single clone, FtF3, which bore the surface phenotype of Sezary cells, was characterized. Monocyte cytotoxicity-inducing factor (MCF) was found to be stable at pH 2 for 1 hr, unlike IFN-gamma, and was found to be more heat stable as well. Moreover, treatment of MCF with antisera to IFN-gamma, IFN-alpha or a combination of IFN-gamma and IFN-alpha failed to neutralize its biologic activity. MCF binds to matrix gel Red A. MCF eluted from this dye-ligand was found to have an apparent m.w. of 11,500 by gel filtration and 14,700 by SDS-polyacrylamide gel electrophoresis. MCF produced by hybridized Sezary cells appear to be neither IFN-gamma nor an altered molecular form of IFN-gamma, yet is a potent inducer of human monocyte cytotoxicity.
D000818:Animals; D055598:Chemical Phenomena; D011232:Chemical Precipitation; D002627:Chemistry, Physical; D002850:Chromatography, Gel; D003602:Cytotoxicity, Immunologic; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D006825:Hybridomas / Q000276:immunology / Q000378:metabolism*; D007106:Immune Sera / Q000494:pharmacology; D007371:Interferon-gamma / Q000378:metabolism; D008222:Lymphokines / Q000096:biosynthesis / Q000302:isolation & purification* / Q000502:physiology; D008262:Macrophage Activation; D016215:Macrophage-Activating Factors; D051379:Mice; D008810:Mice, Inbred C57BL; D009000:Monocytes / Q000276:immunology*; D012751:Sezary Syndrome / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism*
D007106:Immune Sera; D008222:Lymphokines; D016215:Macrophage-Activating Factors; D007371:Interferon-gamma