title: FcγR-driven release of IL-6 by macrophages requires NOX2-dependent production of reactive oxygen species.
abstract: Activation of the FcγR via antigen containing immune complexes can lead to the generation of reactive oxygen species, which are potent signal transducing molecules. However, whether ROS contribute to FcγR signaling has not been studied extensively. We set out to elucidate the role of NADPH oxidase-generated ROS in macrophage activation following FcγR engagement using antigen-containing immune complexes. We hypothesized that NOX2 generated ROS is necessary for propagation of downstream FcγR signaling and initiation of the innate immune response. Following exposure of murine bone marrow-derived macrophages (BMDMs) to inactivated Francisella tularensis (iFt)-containing immune complexes, we observed a significant increase in the innate inflammatory cytokine IL-6 at 24 h compared with macrophages treated with Ft LVS-containing immune complexes. Ligation of the FcγR by opsonized Ft also results in significant ROS production. Macrophages lacking the gp91(phox) subunit of NOX2 fail to produce ROS upon FcγR ligation, resulting in decreased Akt phosphorylation and a reduction in the levels of IL-6 compared with wild type macrophages. Similar results were seen following infection of BMDMs with catalase deficient Ft that fail to scavenge hydrogen peroxide. In conclusion, our findings demonstrate that ROS participate in elicitation of an effective innate immune in response to antigen-containing immune complexes through FcγR.
authors.affiliation: From the Center for Immunology and Microbial Disease, Albany Medical College, Albany, New York 12208 and.
authors.forename: Anthony M
authors.initials: AM
authors.lastname: Franchini
authors.affiliation: From the Center for Immunology and Microbial Disease, Albany Medical College, Albany, New York 12208 and.
authors.forename: Danielle
authors.initials: D
authors.lastname: Hunt
authors.affiliation: the College of Nanoscale Science and Engineering, University at Albany-State University of New York, Albany, New York 12203.
authors.forename: J Andres
authors.initials: JA
authors.lastname: Melendez
authors.affiliation: From the Center for Immunology and Microbial Disease, Albany Medical College, Albany, New York 12208 and. Electronic address: DrakeJ@mail.amc.edu.
authors.forename: James R
authors.initials: JR
authors.lastname: Drake
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D001854:Bone Marrow Cells / Q000276:immunology / Q000378:metabolism*; D002374:Catalase / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D005604:Francisella tularensis / Q000201:enzymology / Q000235:genetics / Q000276:immunology; D006861:Hydrogen Peroxide / Q000276:immunology / Q000378:metabolism*; D007113:Immunity, Innate / Q000502:physiology; D015850:Interleukin-6 / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D008264:Macrophages / Q000276:immunology / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D017452:Receptors, IgG / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D015398:Signal Transduction / Q000235:genetics / Q000276:immunology
chemical_list: D001426:Bacterial Proteins; D015850:Interleukin-6; D008562:Membrane Glycoproteins; D017452:Receptors, IgG; D006861:Hydrogen Peroxide; D002374:Catalase; C488842:Cybb protein, mouse; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases; D051057:Proto-Oncogene Proteins c-akt
keywords: Akt; FC Receptors; Francisella tularensis; Macrophages; NADPH Oxidase; Reactive Oxygen Species (ROS)