Project description:Th17 cells secrete IL-17A, IL-17F, IL-21, and IL-22 cytokines that are critical in mediating inflammation and protecting the host from microorganisms infection. The basic leucine zipper transcription factor ATF-like (Batf) contributes to the transcriptional programming of multiple effector T cells, and is required for Th17 cell development. Here, we have interrogated mechanisms by which Batf promotes and stabilizes Th17 cell phenotype. We have shown that in vitro differentiated Th17 cells have increased expression of Th1 and Treg signature genes in the absence of Batf. In addition, Citrobacter rodentium infected Batf-deficient (Batf KO) mice fail to clear the infection, and that is correlated with diminished IL-17A and IL-22 cytokine production and increased Foxp3 and Ifng expression compared to WT mice. We find that Batf sustains Th17 phenotype in long-term culture conditions by suppressing Th1- and Treg-specific gene expression. Mechanistically, we reveal that Batf negatively regulates IL-2-STAT5 signaling and modulates STAT5 binding at the Ifng and Foxp3 gene loci thus suppressing Th1-Treg phenotype in Th17 cell development. Inhibition of STAT5 DNA binding activity in Batf KO Th17 cells was able to repress Ifng and Foxp3 expression compared to control-treated cells. Moreover, STAT5 cooperates with transcription factors Ets1 and Runx1 to mediate epigenetic modification and regulate gene expression. Thus, our study has revealed an essential function of Batf in modulating the IL-2-STAT5 signaling to promote and stabilize Th17 cell development.
Project description:Th17 cells secrete IL-17A, IL-17F, IL-21, and IL-22 cytokines that are critical in mediating inflammation and protecting the host from microorganisms infection. The basic leucine zipper transcription factor ATF-like (Batf) contributes to the transcriptional programming of multiple effector T cells, and is required for Th17 cell development. Here, we have interrogated mechanisms by which Batf promotes and stabilizes Th17 cell phenotype. We have shown that in vitro differentiated Th17 cells have increased expression of Th1 and Treg signature genes in the absence of Batf. In addition, Citrobacter rodentium infected Batf-deficient (Batf KO) mice fail to clear the infection, and that is correlated with diminished IL-17A and IL-22 cytokine production and increased Foxp3 and Ifng expression compared to WT mice. We find that Batf sustains Th17 phenotype in long-term culture conditions by suppressing Th1- and Treg-specific gene expression. Mechanistically, we reveal that Batf negatively regulates IL-2-STAT5 signaling and modulates STAT5 binding at the Ifng and Foxp3 gene loci thus suppressing Th1-Treg phenotype in Th17 cell development. Inhibition of STAT5 DNA binding activity in Batf KO Th17 cells was able to repress Ifng and Foxp3 expression compared to control-treated cells. Moreover, STAT5 cooperates with transcription factors Ets1 and Runx1 to mediate epigenetic modification and regulate gene expression. Thus, our study has revealed an essential function of Batf in modulating the IL-2-STAT5 signaling to promote and stabilize Th17 cell development.
Project description:Although the activator protein-1 (AP-1) factor Batf is required for Th17 cell development, its mechanisms of action to underpin the Th17 program are incompletely understood. Here, we find that Batf ensures Th17 cell identity in part by restricting alternative gene programs through its actions to restrain IL-2 expression and IL-2-induced Stat5 activation. This, in turn, limits Stat5-dependent recruitment of Ets1-Runx1 factors to Th1- and Treg-cell-specific gene loci. Thus, in addition to pioneering regulatory elements in Th17-specific loci, Batf acts indirectly to inhibit the assembly of a Stat5-Ets1-Runx1 complex that enhances the transcription of Th1- and Treg-cell-specific genes. These findings unveil an important role for Stat5-Ets1-Runx1 interactions in transcriptional networks that define alternate T cell fates and indicate that Batf plays an indispensable role in both inducing and maintaining the Th17 program through its actions to regulate the competing actions of Stat5-assembled enhanceosomes that promote Th1- and Treg-cell developmental programs.
Project description:Although the activator protein-1 (AP-1) factor Batf is required for Th17 cell development, its mechanisms of action to underpin the Th17 program are incompletely understood. Here we find that Batf ensures Th17 cell identity in part by restricting alternative gene programs through its actions to restrain IL-2 expression and IL-2-induced Stat5 activation. This, in turn, limits Stat5-dependent recruitment of Ets1-Runx1 factors to Th1 and Treg cell-specific gene loci. Thus, in addition to pioneering regulatory elements in Th17-specific loci, Batf acts indirectly to inhibit assembly of a Stat5-Ets1-Runx1 complex that enhances transcription of Th1 and Treg cell-specific genes. These findings unveil an important role for Stat5-Ets1-Runx1 interactions in transcriptional networks that define alternate T cell fates and indicate that Batf plays an indispensable role in both inducing and maintaining the Th17 program through its actions to regulate the competing actions of Stat5-assembled enhanceosomes that promote Th1 and Treg-cell developmental programs.
Project description:Interleukin 2 (IL-2), a cytokine linked to human autoimmune diseases, limits IL-17 production. We show that deletion of Stat3 in T cells abrogates IL-17 production and attenuates autoimmunity associated with IL-2 deficiency. While STAT3 induces IL-17 and RORγt and inhibits Foxp3, IL-2 inhibited IL-17 independently of Foxp3 and RORγt. We found that STAT3 and STAT5 bound to multiple common sites across the Il17 genetic locus. The induction of STAT5 binding by IL-2 was associated with a reduction in STAT3 binding at these sites and the inhibition of associated active epigenetic marks. Titrating the relative activation of STAT3 and STAT5 modulated TH17 cell specification. Thus, the balance rather than the absolute magnitude of these signals determines the propensity of cells to make a key inflammatory cytokine. The genome-wide binding of STAT3 and STAT5 under Th17 conditions was investigated by CHIP-seq.