title: Human macrophage activation. Modulation of mannosyl, fucosyl receptor activity in vitro by lymphokines, gamma and alpha interferons, and dexamethasone.
abstract: We describe a sensitive assay to measure immune activation of human macrophages in cell culture. Freshly isolated blood monocytes from normal subjects lack the ability to endocytose and degrade mannosyl-terminated glycoconjugates via specific receptors, but acquired this activity after cultivation in autologous serum for approximately 3 d. Addition of specific antigen, purified protein derivative, or T cell mitogens to mononuclear cells prevented the appearance of macrophage mannosyl receptor activity and lymphokine, gamma-, and alpha-interferons selectively down-regulated receptor activity in monocyte-macrophage targets. The effects of antigen challenge and gamma-interferon on mannosyl receptors can be prevented by 10(-8) M dexamethasone. Dexamethasone also inhibited release of another macrophage activation marker, plasminogen activator, which was increased by both gamma- and alpha-interferons. These studies show that activation of human macrophages is regulated by opposing actions of lymphokines and glucocorticoids.
authors.forename: T
authors.initials: T
authors.lastname: Mokoena
authors.forename: S
authors.initials: S
authors.lastname: Gordon
mesh_terms: D000328:Adult; D000941:Antigens / Q000276:immunology; D003907:Dexamethasone / Q000494:pharmacology; D005342:Fibrinolysis / Q000187:drug effects; D006801:Humans; D066298:In Vitro Techniques; D007372:Interferons / Q000494:pharmacology; D037181:Lectins, C-Type; D008213:Lymphocyte Activation; D008222:Lymphokines / Q000494:pharmacology; D008262:Macrophage Activation / Q000187:drug effects; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins; D008934:Mitogens / Q000494:pharmacology; D009000:Monocytes / Q000502:physiology; D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic / Q000187:drug effects / Q000378:metabolism*
chemical_list: D000941:Antigens; D037181:Lectins, C-Type; D008222:Lymphokines; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins; D008934:Mitogens; D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic; D003907:Dexamethasone; D007372:Interferons