title: Inhibition of type I natural killer T cells by retinoids or following sulfatide-mediated activation of type II natural killer T cells attenuates alcoholic liver disease in mice.
abstract: Innate immune mechanisms leading to liver injury subsequent to chronic alcohol ingestion are poorly understood. Natural killer T (NKT) cells, enriched in the liver and comprised of at least two distinct subsets, type I and II, recognize different lipid antigens presented by CD1d molecules. We have investigated whether differential activation of NKT cell subsets orchestrates inflammatory events leading to alcoholic liver disease (ALD). We found that after chronic plus binge feeding of Lieber-DeCarli liquid diet in male C57BL/6 mice, type I, but not type II, NKT cells are activated, leading to recruitment of inflammatory Gr-1(high) CD11b(+) cells into the liver. A central finding is that liver injury after alcohol feeding is dependent upon type I NKT cells. Thus, liver injury is significantly inhibited in Jα18(-/-) mice deficient in type I NKT cells as well as after their inactivation by sulfatide-mediated activation of type II NKT cells. Furthermore, we have identified a novel pathway involving all-trans retinoic acid (ATRA) and its receptor (RARγ) signaling that inhibits type I NKT cells and, consequently, ALD. A semiquantitative polymerase chain reaction analysis of hepatic gene expression of some of the key proinflammatory molecules shared in human disease indicated that their up-regulation in ALD is dependent upon type I NKT cells.
  
  
  CONCLUSIONS
  Type I, but not type II, NKT cells become activated after alcohol feeding. Type I NKT cell-induced inflammation and neutrophil recruitment results in liver tissue damage whereas type II NKT cells protect from injury in ALD. Inhibition of type I NKT cells by retinoids or by sulfatide prevents ALD. Given that the CD1d pathway is highly conserved between mice and humans, NKT cell subsets might be targeted for potential therapeutic intervention in ALD.
authors.affiliation: Laboratory of Autoimmunity, Torrey Pines Institute for Molecular Studies, San Diego, CA.
authors.forename: Igor
authors.initials: I
authors.lastname: Maricic
authors.forename: Huiming
authors.initials: H
authors.lastname: Sheng
authors.forename: Idania
authors.initials: I
authors.lastname: Marrero
authors.forename: Ekihiro
authors.initials: E
authors.lastname: Seki
authors.forename: Tatiana
authors.initials: T
authors.lastname: Kisseleva
authors.forename: Som
authors.initials: S
authors.lastname: Chaturvedi
authors.forename: Natasha
authors.initials: N
authors.lastname: Molle
authors.forename: Stephanie A
authors.initials: SA
authors.lastname: Mathews
authors.forename: Bin
authors.initials: B
authors.lastname: Gao
authors.forename: Vipin
authors.initials: V
authors.lastname: Kumar
mesh_terms: D000818:Animals; D008108:Liver Diseases, Alcoholic / Q000276:immunology* / Q000517:prevention & control*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D055611:Natural Killer T-Cells / Q000145:classification / Q000187:drug effects* / Q000502:physiology*; D012176:Retinoids / Q000494:pharmacology* / Q000627:therapeutic use*; D013433:Sulfoglycosphingolipids / Q000494:pharmacology* / Q000627:therapeutic use*
chemical_list: D012176:Retinoids; D013433:Sulfoglycosphingolipids