title: Immune complexes increase nitric oxide production by interferon-gamma- stimulated murine macrophage-like J774.16 cells.
abstract: Murine macrophage-like J774.16 cells were tested for changes in nitric oxide production upon incubation with immune complexes. Cryptococcus neoformans capsular polysaccharide and polysaccharide-specific monoclonal antibodies were added to J774.16 cells in the presence and absence of recombinant murine interferon-gamma (IFN-gamma). The effect of immune complexes on nitrite synthesis was both concentration dependent and isotype dependent. In the presence of IFN-gamma, immune complexes of IgG1, IgG2, IgG2b, or IgG3 isotype increased nitrite levels, whereas complexes of IgM isotype did not. Immune complexes did not alter nitrite production by unstimulated macrophages. Antibody alone, antigen alone, and antigen with irrelevant IgG1 antibody did not augment nitrite formation, either in the presence or absence of IFN-gamma, indicating a requirement for Fc gamma R cross-linking. These results suggest that IgG isotypes may offer additional protection against pathogens by enhancing macrophage nitric oxide production.
authors.affiliation: Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
authors.forename: N
authors.initials: N
authors.lastname: Mozaffarian
authors.forename: J W
authors.initials: JW
authors.lastname: Berman
authors.forename: A
authors.initials: A
authors.lastname: Casadevall
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D000936:Antigen-Antibody Complex / Q000494:pharmacology*; D000942:Antigens, Bacterial / Q000494:pharmacology; D002478:Cells, Cultured; D007074:Immunoglobulin G / Q000494:pharmacology; D007132:Immunoglobulin Isotypes / Q000494:pharmacology; D007075:Immunoglobulin M / Q000494:pharmacology; D007371:Interferon-gamma / Q000494:pharmacology*; D007700:Kinetics; D008264:Macrophages / Q000187:drug effects* / Q000378:metabolism*; D051379:Mice; D009569:Nitric Oxide / Q000096:biosynthesis*; D017452:Receptors, IgG / Q000378:metabolism; D011994:Recombinant Proteins; D013268:Stimulation, Chemical
chemical_list: D000911:Antibodies, Monoclonal; D000936:Antigen-Antibody Complex; D000942:Antigens, Bacterial; D007074:Immunoglobulin G; D007132:Immunoglobulin Isotypes; D007075:Immunoglobulin M; D017452:Receptors, IgG; D011994:Recombinant Proteins; D009569:Nitric Oxide; D007371:Interferon-gamma