title: Contribution of IRF5 in B cells to the development of murine SLE-like disease through its transcriptional control of the IgG2a locus.
abstract: Interferon regulatory factor (IRF) 5 is a key transcription factor for the activation of innate immune responses downstream of Toll-like receptor signaling. Based on recent genetic analyses, IRF5 is a focus for its potential involvement in systemic lupus erythematosus (SLE), although how IRF5 contributes to SLE is uncertain. In this study, we demonstrate a requirement for IRF5 in the development of murine SLE via its role in B lymphocytes. We show that antinuclear autoantibodies and Ig glomerular deposits, hallmarks of SLE, are absent in Irf5(-/-) mice challenged to develop SLE by pristane injection. In particular, production of autoantibodies of the IgG2a subtype, the most prominent isotype in inducing autoimmunity, requires IRF5. Finally, we provide evidence for the critical role of this transcription factor in the secretion of pathogenic antibodies through its direct control of class switch recombination of the gamma2a locus. By demonstrating a B-cell-intrinsic role, this study places IRF5 in a context that may have implications for understanding the pathogenesis of human SLE.
authors.affiliation: Department of Immunology, Graduate School of Medicine and Faculty of Medicine, University of Tokyo, Bunkyo-ku, Tokyo 113-0031, Japan.
authors.forename: David A
authors.initials: DA
authors.lastname: Savitsky
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Yanai
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Tamura
authors.forename: Tadatsugu
authors.initials: T
authors.lastname: Taniguchi
authors.forename: Kenya
authors.initials: K
authors.lastname: Honda
mesh_terms: D000818:Animals; D001169:Arthritis, Experimental / Q000276:immunology; D001323:Autoantibodies / Q000096:biosynthesis / Q000235:genetics; D001402:B-Lymphocytes / Q000276:immunology*; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D007113:Immunity, Innate; D007074:Immunoglobulin G / Q000096:biosynthesis / Q000235:genetics*; D050835:Interferon Regulatory Factors / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D008180:Lupus Erythematosus, Systemic / Q000209:etiology* / Q000235:genetics / Q000276:immunology; D008213:Lymphocyte Activation; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D051217:Toll-Like Receptor 9 / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D001323:Autoantibodies; D007074:Immunoglobulin G; D050835:Interferon Regulatory Factors; C498178:Irf5 protein, mouse; C495370:Tlr9 protein, mouse; D051217:Toll-Like Receptor 9