Unveiling IRF4-steered regulation of context-dependent effector programs in CD4+ T cells under Th17- and Treg-skewing conditions

Cell Rep. 2025 Mar 25;44(3):115407. doi: 10.1016/j.celrep.2025.115407. Epub 2025 Mar 10.

Abstract

The transcription factor interferon regulatory factor 4 (IRF4) is crucial for the fate determination of pro-inflammatory T helper (Th) 17 and the functionally opposing group of immunomodulatory regulatory T (Treg) cells. However, the molecular mechanisms of how IRF4 steers diverse transcriptional programs in Th17 and Treg cells are far from being definitive. Here, we integrated data derived from affinity-purification and full mass-spectrometry-based proteome analysis with chromatin immunoprecipitation sequencing. This allowed the characterization of subtype-specific molecular programs and the identification of IRF4 interactors in the Th17/Treg context. Our data reveal that IRF4-interacting transcription factors are recruited to IRF composite elements for the regulation of cell-type-specific transcriptional programs as exemplarily demonstrated for FLI1, which, in cooperation with IRF4, promotes Th17-specific gene expression. FLI1 inhibition markedly impaired Th17 differentiation. The present "omics" dataset provides a valuable resource for studying IRF4-mediated gene regulatory programs in pro- and anti-inflammatory immune responses.

Keywords: CP: Immunology; ChIP-seq; FLI1; IRF4; Th17 cells; Treg cells; composite motif; protein-protein interaction; proteomics.

MeSH terms

  • Adult
  • Animals
  • CD4-Positive T-Lymphocytes* / immunology
  • Female
  • Humans
  • Interferon Regulatory Factors* / genetics
  • Interferon Regulatory Factors* / metabolism
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Middle Aged
  • Protein Binding
  • Proto-Oncogene Protein c-fli-1 / immunology
  • T-Lymphocytes, Regulatory / immunology
  • Th17 Cells* / immunology
  • Transcription, Genetic
  • Young Adult

Substances

  • interferon regulatory factor-4
  • Interferon Regulatory Factors
  • Fli1 protein, mouse
  • Proto-Oncogene Protein c-fli-1