title: IFN-gamma plus glucocorticoids stimulate the expression of a newly identified human mononuclear phagocyte-specific antigen.
abstract: Glucocorticoid hormones, although able to exert profound immunosuppressive effects, do not suppress mononuclear phagocyte activation by IFN-gamma and may even enhance it. For example, expression and functional activity of the high affinity FcR for IgG on human mononuclear phagocytes (FcR gamma I) is increased by IFN-gamma and is maximal after co-treatment with IFN-gamma plus the glucocorticoid dexamethasone (DEX). To determine whether there are other mononuclear phagocyte surface Ag that are regulated in this manner, hybridomas were prepared using IFN-gamma-plus-DEX-treated human monocytes as immunogen. Five IgG1 mAb (Mac 2-8, 2-38, 2-48, 2-49, and 2-158) were developed that recognize a trypsin-sensitive mononuclear phagocyte-specific surface Ag of Mr 155,000. There was no detectable reactivity of these mAb to lymphocytes or granulocytes or to several cell lines, including U-937 and HL-60. The p155 Ag was detected on monocytes and increased significantly with time of culture or after treatment with DEX. Expression was maximal after co-treatment with rIFN-gamma plus DEX, but was inhibited or unaffected by treatment with IFN-gamma alone. For freshly isolated cells, expression of the p155 Ag was highest on peritoneal macrophages. Our results indicate that the p155 Ag is a newly identified Ag of the human mononuclear phagocyte lineage and may represent, in the least, a phenotypic marker of monocyte differentiation or maturation.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D000937:Antigen-Antibody Reactions; D000943:Antigens, Differentiation / Q000276:immunology / Q000302:isolation & purification*; D002460:Cell Line; D000939:Epitopes / Q000276:immunology; D005260:Female; D005938:Glucocorticoids / Q000494:pharmacology*; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology*; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008264:Macrophages / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D009000:Monocytes / Q000276:immunology*; D011233:Precipitin Tests; D011994:Recombinant Proteins / Q000494:pharmacology; D014357:Trypsin
chemical_list: D000911:Antibodies, Monoclonal; D000943:Antigens, Differentiation; D000939:Epitopes; D005938:Glucocorticoids; D011994:Recombinant Proteins; C036763:monocyte-macrophage differentiation antigen; D007371:Interferon-gamma; D014357:Trypsin