Activated hepatic stellate cells impair NK cell anti-fibrosis capacity through a TGF-β-dependent emperipolesis in HBV cirrhotic patients

Sci Rep. 2017 Mar 14:7:44544. doi: 10.1038/srep44544.

Abstract

Natural killer (NK) cells can induce liver fibrosis remission by killing hepatic stellate cells (HSCs) and producing interferon (IFN)-γ in a mouse model; however, their anti-fibrotic immune-characteristics and regulatory mechanisms by HSCs remain to be determined, especially in livers from HBV-infected liver cirrhosis (LC) patients. We analyzed frequency, phenotype and anti-fibrotic function of hepatic and peripheral NK subsets in 43 HBV-LC patients. We found that hepatic NK subsets from LC patients displayed a decreased frequency, activation status and anti-fibrotic activity compared with those from chronic hepatitis B patients, which were mainly mediated by increased intrahepatic tumour-growth factor (TGF)-β because blockade of TGF-β significantly reversed NK anti-fibrotic function in vitro. In vivo, hepatic NK cells were enriched in proximity to the α-smooth muscle actin (α-SMA+) area within mild fibrosis regions; while in severe fibrotic areas, they were either directly attached to or separated from the α-SMA+ region. NK cells from LC patients could enter HSCs to form emperipolesis (a cell-in-cell structure) and become apoptotic; anti-TGF-β treatment ameliorated this emperipolesis. This finding suggested a novel mechanism by which activated HSCs impair NK cells' anti-fibrosis capacity through a TGF-β-dependent emperipolesis in LC patients, providing an anti-fibrotic rational by enhancing NK cell activity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Animals
  • Emperipolesis / genetics
  • Emperipolesis / immunology
  • Female
  • Fibrosis / genetics*
  • Fibrosis / immunology
  • Fibrosis / pathology
  • Hepatic Stellate Cells / immunology
  • Hepatic Stellate Cells / pathology
  • Hepatitis B, Chronic / genetics*
  • Hepatitis B, Chronic / immunology
  • Hepatitis B, Chronic / pathology
  • Hepatitis B, Chronic / virology
  • Humans
  • Interferon-gamma / genetics
  • Killer Cells, Natural / immunology
  • Liver / metabolism
  • Liver / pathology
  • Liver Cirrhosis / genetics*
  • Liver Cirrhosis / immunology
  • Liver Cirrhosis / pathology
  • Male
  • Mice
  • Middle Aged
  • Transforming Growth Factor beta / administration & dosage
  • Transforming Growth Factor beta / genetics*

Substances

  • Transforming Growth Factor beta
  • Interferon-gamma