title: Neutrophil-mediated cytotoxicity induced by secretory IgA.
abstract: Normal human neutrophils triggered by secretory IgA (sIgA) displayed low levels of cytotoxicity towards non-sensitized red blood cells. Catalase completely impaired this non-specific cytotoxicity (NSC), while superoxide dismutase (SOD) significantly enhanced it, suggesting a key role for hydrogen peroxide (H2O2) in the lysis of target cells. Three heme-enzyme inhibitors, sodium azide, sodium cyanide and 3-amino-1,2,4-triazole, did not decrease NSC, but significantly enhanced it, suggesting that the mechanism involved is not dependent upon myeloperoxidase (MPO). Heat-aggregated IgG (HA-IgG) synergize with sIgA in promoting NSC. It was also found that gamma interferon significantly enhanced neutrophil-mediated NSC induced by sIgA, its effect being more dramatic on NSC triggered by low concentrations of sIgA. The significance of these results is discussed.
authors.affiliation: Seción Inmunología Instituto de Investigaciones Hematológicas, Academia Nacional de Medicina, Buenos Aires, Argentina.
authors.forename: J R
authors.initials: JR
authors.lastname: Geffner
authors.forename: F
authors.initials: F
authors.lastname: Minnucci
authors.forename: M A
authors.initials: MA
authors.lastname: Isturiz
mesh_terms: D000640:Amitrole / Q000494:pharmacology; D001386:Azides / Q000494:pharmacology; D002374:Catalase / Q000494:pharmacology; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D007071:Immunoglobulin A, Secretory / Q000276:immunology*; D007074:Immunoglobulin G / Q000276:immunology; D007371:Interferon-gamma / Q000494:pharmacology; D009504:Neutrophils / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D009195:Peroxidase / Q000037:antagonists & inhibitors; D019810:Sodium Azide; D012966:Sodium Cyanide / Q000494:pharmacology; D013482:Superoxide Dismutase / Q000494:pharmacology
chemical_list: D001386:Azides; D007071:Immunoglobulin A, Secretory; D007074:Immunoglobulin G; D007371:Interferon-gamma; D019810:Sodium Azide; D006861:Hydrogen Peroxide; D002374:Catalase; D009195:Peroxidase; D013482:Superoxide Dismutase; D012966:Sodium Cyanide; D000640:Amitrole