Rapid chromatin repression by Aire provides precise control of immune tolerance

Nat Immunol. 2018 Feb;19(2):162-172. doi: 10.1038/s41590-017-0032-8. Epub 2018 Jan 15.

Abstract

Aire mediates the expression of tissue-specific antigens in thymic epithelial cells to promote tolerance against self-reactive T lymphocytes. However, the mechanism that allows expression of tissue-specific genes at levels that prevent harm is unknown. Here we show that Brg1 generates accessibility at tissue-specific loci to impose central tolerance. We found that Aire has an intrinsic repressive function that restricts chromatin accessibility and opposes Brg1 across the genome. Aire exerted this repressive influence within minutes after recruitment to chromatin and restrained the amplitude of active transcription. Disease-causing mutations that impair Aire-induced activation also impair the protein's repressive function, which indicates dual roles for Aire. Together, Brg1 and Aire fine-tune the expression of tissue-specific genes at levels that prevent toxicity yet promote immune tolerance.

Publication types

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

MeSH terms

  • AIRE Protein
  • Animals
  • Central Tolerance / immunology*
  • Chromatin
  • DNA Helicases / immunology*
  • Gene Expression Regulation / immunology*
  • Mice
  • Mice, Transgenic
  • Nuclear Proteins / immunology*
  • Thymus Gland / immunology*
  • Transcription Factors / immunology*

Substances

  • Chromatin
  • Nuclear Proteins
  • Transcription Factors
  • Smarca4 protein, mouse
  • DNA Helicases