Frontiers in Immunology (Jul 2018)

Glucocorticoid-Induced Leucine Zipper Inhibits Interferon-Gamma Production in B Cells and Suppresses Colitis in Mice

  • Stefano Bruscoli,
  • Daniele Sorcini,
  • Sara Flamini,
  • Andrea Gagliardi,
  • Francesco Adamo,
  • Simona Ronchetti,
  • Graziella Migliorati,
  • Oxana Bereshchenko,
  • Carlo Riccardi

DOI
https://doi.org/10.3389/fimmu.2018.01720
Journal volume & issue
Vol. 9

Abstract

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Glucocorticoid-induced leucine zipper (GILZ) is transcriptionally upregulated by glucocorticoids (GCs) and mediates many of the anti-inflammatory effects of GCs. Since B cell activity has been linked to cytokine production and modulation of inflammatory responses, we herein investigated the role of GILZ in B cells during colitis development. B cell-specific gilz knock-out (gilz B cKO) mice exhibited increased production of the pro-inflammatory cytokine IFN-γ in B cells, and consequently CD4+ T cell activation. Increased IFN-γ production in B cells was associated with enhanced transcriptional activity of the transcription factor activator protein-1 (AP-1) on the IFN-γ promoter. Moreover, GILZ deficiency in B cells was linked to enhanced susceptibility to experimental colitis in mice, and this was reversed by administering GILZ protein. Interestingly, we observed increased production of IFN-γ in both B and T cells infiltrating the lamina propria (LP) of gilz B cKO mice. Together, these findings indicate that GILZ controls IFN-γ production in B cells, which also affects T cell activity, and increased production of IFN-γ by B and T cells in LP is associated with predisposition to inflammatory colitis in mice.

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