Identification of Potential Cytokine Pathways for Therapeutic Intervention in Murine Primary Biliary Cirrhosis

• Type of Material: Article
• Authors: Kazuhito Kawata, University of California Davis; Masanobu Tsuda, University of California Davis; Guo-Xiang Yang, University of California Davis; Weici Zhang, University of California Davis; Hajime Tanaka, University of California Davis; Koichi Tsuneyama, University of California Davis; Patrick Leung, University of California Davis; Xiao-Song He, University of California Davis; Stuart Knechtle, The Emory Clinic and Hospital; Aftab A Ansari, Emory University; Ross L. Coppel, Monash University; M. Eric Gershwin, University of California Davis
• Language: English
• Date: 2013-09-10
• Publisher: Public Library of Science
• Publication Version: Final Published Version
• Copyright Statement: © 2013 Kawata et al
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1371/journal.pone.0074225
• Title of Journal or Parent Work: PLoS ONE
• ISSN: 1932-6203
• Volume: 8
• Issue: 9
• Start Page: e74225
• End Page: e74225
• Grant/Funding Information: This work was supported by funds from National Institutes of Health grant DK067003.
• Keywords: IL-12; II MICE; MOUSE MODEL; INFLAMMATION; Mouse models; Multidisciplinary Sciences; Inflammation; T-CELL; EXPERIMENTAL AUTOIMMUNE ENCEPHALOMYELITIS; Flow cytometry; Antibodies; Science & Technology - Other Topics; TH17 CELLS; Bile ducts; Cytokines; Primary biliary cirrhosis; T cells; C57BL/6 MICE; IL-23; INDUCTION; Science & Technology
• Research Categories: Biology, Virology; Health Sciences, Immunology; Biology, Microbiology

Abstract

Primary biliary cirrhosis (PBC) is considered a model autoimmune disease, with the most highly directed and specific autoantibody in both murine and human autoimmunity, the anti-mitochondrial autoantibody (AMA). However, therapeutic advances in this disease have lagged behind. Herein we have taken advantage of our unique model of murine PBC in which mice immunized with 2-octynoic acid coupled to BSA (2OA-BSA), a compound identified by quantitative structure activity relationships (QSAR) of human AMA binding, develop an intense inflammatory cholangitis with striking similarities to humans with PBC. In particular, we have constructed several unique gene-deleted mice, including mice deleted of IL-12p40, IL-12p35, IFN-γ, IL-23p19, IL-17A, IL-17F and IL-22, immunized these animals with 2OA-BSA and followed the natural history of immunopathology to identify key pathways that might provide clues for successful therapy. Our data indicate that whereas both IL-12/Th1 and IL-23/Th17 are involved in cholangitis, it is the IL-12/Th1 signaling pathway that elicits pathology. In fact, deletion of IFN-γ prevents disease and suppresses autoantibodies. Importantly, deletion of the Th17 cytokines IL-17A and IL-22, but not IL-17F, reduces biliary damage; IL-17A-knockout mice have reduced levels of anti-mitochondrial antibody. We further demonstrate that the production of IFN-γ is significantly decreased in the liver of IL-23p19(-/-), IL-17A(-/-) and IL-22(-/-) mice compared with controls. However, the ability of T cells to produce IFN-γ was not affected in Th17 cytokine-deficient mice. Our data indicate that a deficient Th17 pathway suppresses the accumulation of IFN-γ producing cells in liver during the early phase of cholangitis. In conclusion, whereas IFN-γ has a pivotal role in the early events involved in the pathogenesis of autoimmune cholangitis induced by 2OA-BSA, the IL-23/Th17 pathway potentiates the effects of IL-12/IFN-γ-mediated immunopathology.