CXCR3-dependent recruitment and CCR6-mediated positioning of Th-17 cells in the inflamed liver

Research output: Contribution to journalArticle

Abstract

Background & Aims IL-17 secreting CD4 (Th17) and CD8 (Tc17) T cells have been implicated in immune-mediated liver diseases, but the molecular basis for their recruitment and positioning within the liver is unknown. Methods The phenotype and migratory behaviour of human liver-derived Th17 and Tc17 cells were investigated by flow cytometry and chemotaxis and flow-based adhesion assays. The recruitment of murine Th17 cells to the liver was studied in vivo using intra-vital microscopy. Results IL-17+ T cells comprised 1–3% of the T cell infiltrate in inflammatory liver diseases and included both CD4 (Th17) and CD8 (Tc17) cells. They expressed RORC and the IL-23 receptor and included subsets that secreted IL-22 and interferon-γ. Th17 and Tc17 cells expressed high levels of CXCR3 and CCR6, Tc17 cells also expressed CXCR6. Binding to human sinusoidal endothelium from flow was dependent on β1 and β2 integrins, CXCR3, and, in the case of Th17 cells, VAP-1. Th17 recruitment via sinusoids in mice with liver inflammation was reduced by treatment with antibodies against CXCR3 ligands, confirming the role of CXCR3 in Th17 recruitment in vivo. In human liver, IL-17+ cells were detected in portal infiltrates close to inflamed bile ducts expressing the CCR6 ligand CCL20. Cytokine-treated human cholangiocytes secreted CCL20 and induced CCR6-dependent migration of Th17 cells suggesting that local cholangiocyte chemokine secretion localises Th17 cells to bile ducts. Conclusions CXCR3 promotes recruitment of Th17 cells from the blood into the liver in both human and murine liver injury. Their subsequent positioning near bile ducts is dependent on cholangiocyte-secreted CCL20. Abbreviations Th17, interleukin-17 secreting CD4 T helper cells; Tc17, interleukin-17 secreting CD8 T helper cells; LIL, liver infiltrating lymphocytes; HSEC, hepatic sinusoidal endothelial cell; BEC, biliary epithelial cells; RORC, retinoic acid-related orphan receptor c; AIH, autoimmune hepatitis; HCV, chronic hepatitis C; PBC, primary biliary cirrhosis; ALD, alcoholic liver disease; NANB, non-A non-B acute hepatitis; NASH, non-alcoholic steato-hepatitis; NL, normal liver; CCL4, carbon tetrachloride; ConA, concanavalin A; TNF-α, tumour necrosis factor-α; IFN-γ, interferon gamma; CFSE, carboxyfluorescein succinimidyl ester

Details

Original languageEnglish
Pages (from-to)1044-1051
Number of pages8
JournalJournal of Hepatology
Volume57
Issue number5
Early online date13 Jul 2012
Publication statusPublished - Nov 2012

Keywords

  • Interleukin-17 , Hepatitis , Th17 cells , Tc17 cells , liver, bile ducts, Chemokine receptor , Chemokine , Concanavalin A