CXCR6 marks a novel subset of T-bet(lo)Eomes(hi) natural killer cells residing in human liver

Sci Rep. 2016 May 23:6:26157. doi: 10.1038/srep26157.

Abstract

Natural killer cells (NK) are highly enriched in the human liver, where they can regulate immunity and immunopathology. We probed them for a liver-resident subset, distinct from conventional bone-marrow-derived NK. CXCR6+ NK were strikingly enriched in healthy and diseased liver compared to blood (p < 0.0001). Human hepatic CXCR6+ NK had an immature phenotype (predominantly CD56(bright)CD16-CD57-), and expressed the tissue-residency marker CD69. CXCR6+ NK produced fewer cytotoxic mediators and pro-inflammatory cytokines than the non-liver-specific CXCR6- fraction. Instead CXCR6+ NK could upregulate TRAIL, a key death ligand in hepatitis pathogenesis. CXCR6 demarcated liver NK into two transcriptionally distinct populations: T-bet(hi)Eomes(lo)(CXCR6-) and T-bet(lo)Eomes(hi)(CXCR6+); the latter was virtually absent in the periphery. The small circulating CXCR6+ subset was predominantly T-bet(hi)Eomes(lo), suggesting its lineage was closer to CXCR6- peripheral than CXCR6+ liver NK. These data reveal a large subset of human liver-resident T-bet(lo)Eomes(hi) NK, distinguished by their surface expression of CXCR6, adapted for hepatic tolerance and inducible anti-viral immunity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Cytokines / metabolism
  • Female
  • Humans
  • Immunophenotyping
  • Killer Cells, Natural / chemistry
  • Killer Cells, Natural / classification
  • Killer Cells, Natural / immunology*
  • Liver / immunology*
  • Lymphocyte Subsets / chemistry
  • Lymphocyte Subsets / classification
  • Lymphocyte Subsets / immunology*
  • Male
  • Middle Aged
  • Receptors, CXCR6 / analysis*
  • T-Box Domain Proteins / analysis*
  • Young Adult

Substances

  • CXCR6 protein, human
  • Cytokines
  • EOMES protein, human
  • Receptors, CXCR6
  • T-Box Domain Proteins
  • T-box transcription factor TBX21