Stat6 and c-Jun mediate Th2 cell-specific IL-24 gene expression

A Sahoo, CG Lee, A Jash, JS Son, G Kim… - The Journal of …, 2011 - journals.aai.org
A Sahoo, CG Lee, A Jash, JS Son, G Kim, HK Kwon, JS So, SH Im
The Journal of Immunology, 2011journals.aai.org
TCR signaling regulates multiple aspects of T cell function by controlling expression of
various cytokine genes. IL-24 is a multifunctional cytokine belonging to the IL-10 family. It
displays anticancer effects in diverse cancer cells and regulates immunopathology of
psoriasis and rheumatoid arthritis. IL-24 also plays an important role in B cell differentiation.
Mouse IL-24 gene is selectively expressed in activated Th2 cells upon TCR stimulation.
However, the molecular mechanisms by which TCR stimulation induces IL-24 gene …
Abstract
TCR signaling regulates multiple aspects of T cell function by controlling expression of various cytokine genes. IL-24 is a multifunctional cytokine belonging to the IL-10 family. It displays anticancer effects in diverse cancer cells and regulates immunopathology of psoriasis and rheumatoid arthritis. IL-24 also plays an important role in B cell differentiation. Mouse IL-24 gene is selectively expressed in activated Th2 cells upon TCR stimulation. However, the molecular mechanisms by which TCR stimulation induces IL-24 gene expression are still unclear. In this study, to elucidate the mechanism of Th2 cell-specific expression of IL-24, we identified a proximal promoter region (− 157/+ 95bp) that plays critical role in activating the IL-24 gene in Th2 cells. This region has a Th2 cell-specific open chromatin structure along with permissive histone modifications. In vivo binding of Stat6 and AP-1 (c-Jun) to the IL-24 promoter locus in Th2 cells synergistically transactivated the IL-24 promoter. Stat6 and c-Jun proteins were found to physically cooperate with each other and upregulated IL-24 gene transcription. Knockdown of either Stat6 or c-Jun suppressed endogenous IL-24 gene expression in Th2 cells. In summary, TCR stimulation induces IL-24 expression in Th2 cells by the coordinate action of Stat6 and c-Jun transcription factors at the transcriptional level.
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