IL-23 restoration of Th17 effector function is independent of IL-6 and TGF-β in a mouse model of alcohol and burn injury

J Leukoc Biol. 2017 Sep;102(3):915-923. doi: 10.1189/jlb.3A1216-527R. Epub 2017 Jul 6.

Abstract

T cells play a critical role in host defense against intestinal bacteria. We have shown that ethanol combined with burn injury suppresses Peyer's patch (PP) Th17 cytokines 1 d after injury. We assessed the mechanism of suppressed Th17 effector functions. Mice were gavaged with ethanol 4 h before burn injury and euthanized 1, 3, and 7 d after injury. Mesenteric lymph nodes (MLNs), PPs, and spleen Th1 and Th17 cytokines were assessed. A significant decrease in IL-17, IL-22, IL-2, and IFN-γ were observed in all 3 lymphoid organs 1 and 3 d after injury. We used splenic cells to study the role of IL-6, IL-23, TGF-β, and aryl hydrocarbon receptor (AHR) in suppressing Th17 cytokines. We also assessed whether the AHR agonist 6-formylindolo (3, 2-b) carbazole (FICZ) modulates Th17 cytokines. We found a significant decrease in IL-6 and TGF-β after ethanol and burn; IL-23 was undetectable. The reconstitution of IL-23 in culture medium increased IL-17 by 2-fold and IL-22 by 20-fold in cells from burn ethanol mice. The restoration of IL-6 and TGF-β combined did not influence the release of Th17 cytokines. We observed that AHR was necessary for IL-23 restoration of IL-22 after ethanol and burn injury. The AHR agonist FICZ enhanced IL-22, but not IL-17. None of these treatments influenced the release of Th1 cytokines. Together, these results suggest that IL-23 plays a critical role in regulation of Th17 cytokines. Furthermore, IL-6 and TGF-β do not appear to influence IL-23-mediated restoration of Th17 cytokines after ethanol and burn injury.

Keywords: T cell; aryl hydrocarbon receptor; cytokines; trauma.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Alcohol-Induced Disorders* / drug therapy
  • Alcohol-Induced Disorders* / immunology
  • Alcohol-Induced Disorders* / pathology
  • Animals
  • Burns* / drug therapy
  • Burns* / immunology
  • Burns* / pathology
  • Disease Models, Animal
  • Interleukin-23* / immunology
  • Interleukin-23* / pharmacology
  • Interleukin-6 / immunology*
  • Male
  • Mice
  • Th1 Cells / immunology
  • Th1 Cells / pathology
  • Th17 Cells / immunology*
  • Th17 Cells / pathology
  • Transforming Growth Factor beta / immunology*

Substances

  • Interleukin-23
  • Interleukin-6
  • Transforming Growth Factor beta
  • interleukin-6, mouse