Phosphorylation of IRF4 by ROCK2 regulates IL-17 and IL-21 production and the development of autoimmunity in mice
Partha S. Biswas, … , Govind Bhagat, Alessandra B. Pernis
Partha S. Biswas, … , Govind Bhagat, Alessandra B. Pernis
Published August 9, 2010
Citation Information: J Clin Invest. 2010;120(9):3280-3295. https://doi.org/10.1172/JCI42856.
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Research Article Autoimmunity

Phosphorylation of IRF4 by ROCK2 regulates IL-17 and IL-21 production and the development of autoimmunity in mice

Abstract

Deregulated production of IL-17 and IL-21 plays a key pathogenic role in many autoimmune disorders. A delineation of the mechanisms that underlie the inappropriate synthesis of IL-17 and IL-21 in autoimmune diseases can thus provide important insights into potential therapies for these disorders. Here we have shown that the serine-threonine kinase Rho-associated, coiled-coil–containing protein kinase 2 (ROCK2) becomes activated in mouse T cells under Th17 skewing conditions and phosphorylates interferon regulatory factor 4 (IRF4), a transcription factor that is absolutely required for the production of IL-17 and IL-21. We furthermore demonstrated that ROCK2-mediated phosphorylation of IRF4 regulated the synthesis of IL-17 and IL-21 and the differentiation of Th17 cells. Whereas CD4+ T cells from WT mice activated ROCK2 physiologically under Th17 conditions, CD4+ T cells from 2 different mouse models of spontaneous autoimmunity aberrantly activated ROCK2 under neutral conditions. Moreover, administration of ROCK inhibitors ameliorated the deregulated production of IL-17 and IL-21 and the inflammatory and autoantibody responses observed in these autoimmune mice. Our findings thus uncover a crucial link among ROCK2, IRF4, and the production of IL-17 and IL-21 and support the idea that selective inhibition of ROCK2 could represent an important therapeutic regimen for the treatment of autoimmune disorders.

Authors

Partha S. Biswas, Sanjay Gupta, Emily Chang, Li Song, Roslynn A. Stirzaker, James K. Liao, Govind Bhagat, Alessandra B. Pernis

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Figure 2

ROCK2 inhibition ameliorates aberrant production of IL-17 and IL-21 by Def6-deficient CD4+ T cells.

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ROCK2 inhibition ameliorates aberrant production of IL-17 and IL-21 by D...
(A) Purified CD4+ T cells from Def6+/+DO11.10 (white bars) or Def6trap/trapDO11.10 (black bars) mice were either left unstimulated or restimulated with anti-CD3 and anti-CD28 mAbs for 48 hours in the presence or absence of 10 or 30 μM Y27632 or Fasudil. Supernatants were then collected and assayed for IL-17 and IL-21 production by ELISA. Data are representative of 3 independent experiments. *P ≤ 0.03. (B) CD4+ T cells from Def6+/+ or Def6trap/trap mice were infected with control YFP-RV or DN-ROCK2–expressing retroviruses. Cells were harvested after 6 days, sorted for YFP+ cells, and restimulated with anti-CD3 and anti-CD28 for 48 hours. Supernatants were then collected and assayed for IL-17 and IL-21 production by ELISA. Data are representative of 3 independent experiments. V, vector control. *P ≤ 0.01. (C) CD4+ T cells from Def6+/+ or Def6trap/trap mice were infected with control GFP-RV or DN-RhoA–expressing retroviruses. Cells were harvested after 6 days, sorted for GFP+ cells, and restimulated with anti-CD3 and anti-CD28 for 48 hours. Supernatants were then collected and assayed for IL-17 and IL-21 production by ELISA. V, vector control. Data are representative of 3 independent experiments. *P ≤ 0.0002.