title: Restoration of Fc receptor-mediated desensitization of superoxide generation in human PMN by PMA.
abstract: The superoxide (O2-) generating activity of human polymorphonuclear leukocytes (PMN) was suppressed more than 50% compared with control cells by preincubation of the cells with soluble immune complexes (Fc receptor-mediated desensitization). The suppression was observed when wheat germ agglutinin (WGA) or N-formyl-L-methionyl-L-leucyl-phenylalanine (fMLP) was used as stimuli for O2- generation. However, the desensitized cells could produce as much O2- as control cells when they were stimulated with phorbol myristate acetate (PMA). The desensitized cells were pre-exposed to a small dose of PMA for a short period (2-3 min). By this procedure, the activity of the cells for WGA or fMLP induced O2- generation was almost completely restored. Similarly, the inhibitory effect of 3'-deazaadenosing on WGA, fMLP or immune complexes (IC) induced O2- generation was abolished by the short-term pre-exposure of the cells to a small dose of PMA.
mesh_terms: D000936:Antigen-Antibody Complex / Q000276:immunology; D006801:Humans; D066298:In Vitro Techniques; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000502:physiology*; D011961:Receptors, Fc / Q000502:physiology*; D013481:Superoxides / Q000096:biosynthesis*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D014372:Tubercidin / Q000494:pharmacology; D014909:Wheat Germ Agglutinins / Q000494:pharmacology
chemical_list: D000936:Antigen-Antibody Complex; D011961:Receptors, Fc; D014909:Wheat Germ Agglutinins; C018258:3-deazaadenosine; D013481:Superoxides; D009240:N-Formylmethionine Leucyl-Phenylalanine; D014372:Tubercidin; D013755:Tetradecanoylphorbol Acetate