Dysregulated RASGRP1 expression through RUNX1 mediated transcription promotes autoimmunity

Eur J Immunol. 2021 Feb;51(2):471-482. doi: 10.1002/eji.201948451. Epub 2020 Nov 16.


RasGRP1 is a Ras guanine nucleotide exchange factor, and an essential regulator of lymphocyte receptor signaling. In mice, Rasgrp1 deletion results in defective T lymphocyte development. RASGRP1-deficient patients suffer from immune deficiency, and the RASGRP1 gene has been linked to autoimmunity. However, how RasGRP1 levels are regulated, and if RasGRP1 dosage alterations contribute to autoimmunity remains unknown. We demonstrate that diminished Rasgrp1 expression caused defective T lymphocyte selection in C57BL/6 mice, and that the severity of inflammatory disease inversely correlates with Rasgrp1 expression levels. In patients with autoimmunity, active inflammation correlated with decreased RASGRP1 levels in CD4+ T cells. By analyzing H3K27 acetylation profiles in human T cells, we identified a RASGRP1 enhancer that harbors autoimmunity-associated SNPs. CRISPR-Cas9 disruption of this enhancer caused lower RasGRP1 expression, and decreased binding of RUNX1 and CBFB transcription factors. Analyzing patients with autoimmunity, we detected reduced RUNX1 expression in CD4+ T cells. Lastly, we mechanistically link RUNX1 to transcriptional regulation of RASGRP1 to reveal a key circuit regulating RasGRP1 expression, which is vital to prevent inflammatory disease.

Keywords: RASGRP1; RUNX1; T cells; autoimmunity; transcription.

Publication types

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

MeSH terms

  • Animals
  • Autoimmunity / genetics*
  • Autoimmunity / immunology
  • CD4-Positive T-Lymphocytes / immunology
  • CRISPR-Cas Systems / genetics
  • CRISPR-Cas Systems / immunology
  • Core Binding Factor Alpha 2 Subunit / genetics*
  • Core Binding Factor Alpha 2 Subunit / immunology
  • DNA-Binding Proteins / genetics*
  • DNA-Binding Proteins / immunology
  • Gene Expression Regulation / genetics
  • Gene Expression Regulation / immunology
  • Guanine Nucleotide Exchange Factors / genetics*
  • Guanine Nucleotide Exchange Factors / immunology
  • Histones / genetics
  • Histones / immunology
  • Humans
  • Inflammation / genetics
  • Inflammation / immunology
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Transcription, Genetic / genetics*
  • Transcription, Genetic / immunology


  • Core Binding Factor Alpha 2 Subunit
  • DNA-Binding Proteins
  • Guanine Nucleotide Exchange Factors
  • Histones
  • RASGRP1 protein, human
  • RUNX1 protein, human