title: IL-12/Th1 and IL-23/Th17 biliary microenvironment in primary biliary cirrhosis: implications for therapy.
abstract: The interleukin (IL)-12/IL-23-mediated Th1/Th17 signaling pathway has been associated with the etiopathogenesis of primary biliary cirrhosis (PBC). To address the cytokine microenvironment specifically in the liver, we examined the localized expression of cytokine subunits and their corresponding receptors using previously optimized immunohistochemistry with an extensive panel of antibodies directed at IL-12p70, IL-12p35, interferon-gamma (IFN-γ), IL-12RB2, IL-23p40, IL-23p19, IL-17, and IL-23R using liver from PBC (n = 51) and non-PBC (n = 80) control liver disease patients. Multiple portal tracts in each patient were blindly evaluated and individually scored. We report herein that although IL-12/Th1 and IL-23/Th17 staining was detected in all of the liver sections, they were primarily localized around the damaged interlobular bile ducts in PBC. Most important, Th17 skewing was prominent in advanced PBC patients with intensive secretion of IL-23p19 by inflamed hepatocytes around IL-23R, IL-12RB2, and IFN-γ expressing degenerated cholangiocytes. Our novel finding on the direct association of Th17 skewing and disease severity illustrates the significance of the IL-23/Th17 pathway in the perpetuation of IL-12/Th1-mediated immunopathology in PBC. Furthermore, localized IL-23p19 production by hepatocytes may enhance profibrotic Th17 signaling and proinflammatory IFN-γ production that contribute to PBC pathology.
  
  
  CONCLUSIONS
  Our data emphasize the pathogenic relevance of IL-12/Th1 and IL-23/Th17 in the evolution of PBC. Of significance, however, the shift from a Th1 to a Th17 imbalance at advanced stages of the disease suggests the necessity to consider modulation of the IL-23/Th17 pathway as a potential target for therapeutic intervention.
authors.affiliation: Division of Rheumatology, Allergy and Clinical Immunology, University of California, Davis, CA, USA.
authors.forename: Chen-Yen
authors.initials: CY
authors.lastname: Yang
authors.forename: Xiong
authors.initials: X
authors.lastname: Ma
authors.forename: Koichi
authors.initials: K
authors.lastname: Tsuneyama
authors.forename: Shanshan
authors.initials: S
authors.lastname: Huang
authors.forename: Toru
authors.initials: T
authors.lastname: Takahashi
authors.forename: Naga P
authors.initials: NP
authors.lastname: Chalasani
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Bowlus
authors.forename: Guo-Xiang
authors.initials: GX
authors.lastname: Yang
authors.forename: Patrick S C
authors.initials: PS
authors.lastname: Leung
authors.forename: Aftab A
authors.initials: AA
authors.lastname: Ansari
authors.forename: Linda
authors.initials: L
authors.lastname: Wu
authors.forename: Ross L
authors.initials: RL
authors.lastname: Coppel
authors.forename: M Eric
authors.initials: ME
authors.lastname: Gershwin
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007371:Interferon-gamma / Q000378:metabolism; D018664:Interleukin-12 / Q000502:physiology*; D053759:Interleukin-23 / Q000502:physiology*; D008105:Liver Cirrhosis, Biliary / Q000209:etiology* / Q000473:pathology / Q000628:therapy; D008297:Male; D008875:Middle Aged; D015398:Signal Transduction / Q000502:physiology; D018417:Th1 Cells / Q000502:physiology*; D058504:Th17 Cells / Q000502:physiology*
chemical_list: D053759:Interleukin-23; D018664:Interleukin-12; D007371:Interferon-gamma