The RNA-binding protein tristetraprolin regulates RALDH2 expression by intestinal dendritic cells and controls local Treg homeostasis

Mucosal Immunol. 2021 Jan;14(1):80-91. doi: 10.1038/s41385-020-0302-x. Epub 2020 May 28.

Abstract

AU-rich element (ARE)-mediated mRNA decay represents a key mechanism to avoid excessive production of inflammatory cytokines. Tristetraprolin (TTP, encoded by Zfp36) is a major ARE-binding protein, since Zfp36-/- mice develop a complex multiorgan inflammatory syndrome that shares many features with spondyloarthritis. The role of TTP in intestinal homeostasis is not known. Herein, we show that Zfp36-/- mice do not develop any histological signs of gut pathology. However, they display a clear increase in intestinal inflammatory markers and discrete alterations in microbiota composition. Importantly, oral antibiotic treatment reduced both local and systemic joint and skin inflammation. We further show that absence of overt intestinal pathology is associated with local expansion of regulatory T cells. We demonstrate that this is related to increased vitamin A metabolism by gut dendritic cells, and identify RALDH2 as a direct target of TTP. In conclusion, these data bring insights into the interplay between microbiota-dependent gut and systemic inflammation during immune-mediated disorders, such as spondyloarthritis.

Publication types

  • Research Support, N.I.H., Intramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aldehyde Oxidoreductases / genetics*
  • Aldehyde Oxidoreductases / metabolism
  • Animals
  • Cytokines / metabolism
  • Dendritic Cells / immunology*
  • Dendritic Cells / metabolism*
  • Disease Susceptibility
  • Gene Expression Regulation
  • Homeostasis*
  • Inflammation Mediators / metabolism
  • Mice
  • Mice, Knockout
  • RNA-Binding Proteins / metabolism
  • T-Lymphocytes, Regulatory / immunology*
  • T-Lymphocytes, Regulatory / metabolism*
  • Tristetraprolin / metabolism*

Substances

  • Cytokines
  • Inflammation Mediators
  • RNA-Binding Proteins
  • Tristetraprolin
  • Aldehyde Oxidoreductases
  • RALDH2 protein, mouse