The microbiota maintain homeostasis of liver-resident γδT-17 cells in a lipid antigen/CD1d-dependent manner

Nat Commun. 2017 Jan 9:7:13839. doi: 10.1038/ncomms13839.

Abstract

The microbiota control regional immunity using mechanisms such as inducing IL-17A-producing γδ T (γδT-17) cells in various tissues. However, little is known regarding hepatic γδT cells that are constantly stimulated by gut commensal microbes. Here we show hepatic γδT cells are liver-resident cells and predominant producers of IL-17A. The microbiota sustain hepatic γδT-17 cell homeostasis, including activation, survival and proliferation. The global commensal quantity affects the number of liver-resident γδT-17 cells; indeed, E. coli alone can generate γδT-17 cells in a dose-dependent manner. Liver-resident γδT-17 cell homeostasis depends on hepatocyte-expressed CD1d, that present lipid antigen, but not Toll-like receptors or IL-1/IL-23 receptor signalling. Supplementing mice in vivo or loading hepatocytes in vitro with exogenous commensal lipid antigens augments the hepatic γδT-17 cell number. Moreover, the microbiota accelerate nonalcoholic fatty liver disease through hepatic γδT-17 cells. Thus, our work describes a unique liver-resident γδT-17 cell subset maintained by gut commensal microbes through CD1d/lipid antigens.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, CD1d / metabolism*
  • Cells, Cultured
  • Escherichia coli / immunology
  • Gastrointestinal Microbiome / immunology*
  • Hepatocytes / immunology
  • Interleukin-17 / biosynthesis
  • Liver / cytology*
  • Lymphocyte Activation / immunology
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Non-alcoholic Fatty Liver Disease / immunology
  • Non-alcoholic Fatty Liver Disease / pathology
  • Receptors, Antigen, T-Cell, gamma-delta / immunology*
  • Th17 Cells / immunology*

Substances

  • Antigens, CD1d
  • CD1d antigen, mouse
  • Il17a protein, mouse
  • Interleukin-17
  • Receptors, Antigen, T-Cell, gamma-delta