iNKT cells prevent obesity-induced hepatic steatosis in mice in a C-C chemokine receptor 7-dependent manner

Int J Obes (Lond). 2018 Feb;42(2):270-279. doi: 10.1038/ijo.2017.200. Epub 2017 Aug 16.

Abstract

Non-alcoholic fatty liver disease and non-alcoholic steatohepatitis are characterized by an increase in hepatic triglyceride content with infiltration of immune cells, which can cause steatohepatitis and hepatic insulin resistance. C-C chemokine receptor 7 (CCR7) is primarily expressed in immune cells, and CCR7 deficiency leads to the development of multi-organ autoimmunity, chronic renal disease and autoimmune diabetes. Here, we investigated the effect of CCR7 on hepatic steatosis in a mouse model and its underlying mechanism. Our results demonstrated that body and liver weights were higher in the CCR7-/- mice than in the wild-type (WT) mice when they were fed a high-fat diet. Further, glucose tolerance and insulin sensitivity were markedly diminished in CCR7-/- mice. The number of invariant natural killer T (iNKT) cells was reduced in the livers of the CCR7-/- mice. Moreover, liver inflammation was detected in obese CCR7-/- mice, which was ameliorated by the adoptive transfer of hepatic mononuclear cells from WT mice, but not through the transfer of hepatic mononuclear cells from CD1d-/- or interleukin-10-deficient (IL-10-/-) mice. Overall, these results suggest that CCR7+ mononuclear cells in the liver could regulate obesity-induced hepatic steatosis via induction of IL-10-expressing iNKT cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Disease Models, Animal
  • Inflammation / metabolism
  • Inflammation / physiopathology*
  • Liver / pathology*
  • Male
  • Mice
  • Mice, Obese
  • Natural Killer T-Cells / physiology*
  • Non-alcoholic Fatty Liver Disease / etiology
  • Non-alcoholic Fatty Liver Disease / pathology*
  • Obesity / metabolism
  • Obesity / physiopathology*
  • Receptors, CCR7 / metabolism*
  • Triglycerides

Substances

  • Ccr7 protein, mouse
  • Receptors, CCR7
  • Triglycerides