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 ROR?t and inhibits Foxp3, IL-2 inhibited IL-17 independently of Foxp3 and ROR?t. 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 roles of STAT3 and STAT5 in regulation of gene expression under Th17 differentiation was investigated. Affymetrix Mouse Genome 430 2.0 Arrays were used to evaluate global gene expression.
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.
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.
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.
Project description:Interleukin-21 (IL-21) is a type 1 cytokine essential for immune cell differentiation and function. Although IL-21 can activate several STAT family transcription factors, previous studies focused mainly on the role of STAT3 in IL-21 signaling. Here, we investigated the role of STAT1 and show that STAT1 and STAT3 have at least partially opposing roles in IL-21 signaling in CD4+ T cells. IL-21 induced STAT1 phosphorylation, and this was augmented in Stat3-deficient CD4+ T cells. RNA-Seq analysis of CD4+ T cells from Stat1- and Stat3-deficient mice revealed that both STAT1 and STAT3 are critical for IL-21-mediated gene regulation. Expression of some genes, including Tbx21 and Ifng, was differentially regulated by STAT1 and STAT3, and interestingly, ChIP-Seq analysis showed that STAT3 binding at Tbx21 and Ifng loci was attenuated in Stat1-deficient cells. Moreover, opposing actions of STAT1 and STAT3 on IFN- expression in CD4+ T cells were demonstrated in vivo during chronic lymphocytic choriomeningitis (LCMV) infection. Finally, IL-21-mediated induction of STAT1 phosphorylation, as well as IFNG and TBX21 expression, were higher in CD4+ T cells from patients with autosomal dominant hyper-IgE syndrome (AD-HIES), which is caused by STAT3 deficiency. These data indicate an interplay between STAT1 and STAT3 in fine-tuning IL-21 actions. Genome-wide transcription factors mapping and binding of STAT3 in mouse CD4+ T cells in both WT and Stat1-deficient mice. RNA-Seq is performed in mouse CD4+ T cells in WT, Stat1-deficient and Stat3-deficient mice.
Project description:Interleukin-21 (IL-21) has broad actions on T- and B-cells, but its actions in innate immunity are poorly understood. Here we show that IL-21 induced apoptosis of conventional dendritic cells (cDCs) via STAT3 and Bim, and this was inhibited by granulocyte-macrophage colony-stimulating factor (GM-CSF). ChIP-Seq analysis revealed genome-wide binding competition between GM-CSF-induced STAT5 and IL-21-induced STAT3. Expression of IL-21 in vivo decreased cDC numbers, and this was prevented by GM-CSF. Moreover, repetitive M-NM-1-galactosylceramide injection of mice induced IL-21 but decreased GM-CSF production by natural killer T (NKT) cells, correlating with decreased cDC numbers. Furthermore, adoptive-transfer of wild-type CD4+ T cells caused more severe colitis with increased DCs and interferon (IFN)-M-NM-3-producing CD4+ T cells in Il21r-/-Rag2-/- mice (which lack T cells and have IL-21-unresponsive DCs) than in Rag2-/- mice. Thus, IL-21 and GM-CSF exhibit cross-regulatory actions on gene regulation and apoptosis, regulating cDC numbers and thereby the magnitude of the immune response. Total 6 samples were examined. Splenic dendritic cells were treated with IL-21 and/or GM-CSF studying STAT3 and STAT5B binding in the genome
Project description:Interleukin-21 (IL-21) is a type 1 cytokine essential for immune cell differentiation and function. Although IL-21 can activate several STAT family transcription factors, previous studies focused mainly on the role of STAT3 in IL-21 signaling. Here, we investigated the role of STAT1 and show that STAT1 and STAT3 have at least partially opposing roles in IL-21 signaling in CD4+ T cells. IL-21 induced STAT1 phosphorylation, and this was augmented in Stat3-deficient CD4+ T cells. RNA-Seq analysis of CD4+ T cells from Stat1- and Stat3-deficient mice revealed that both STAT1 and STAT3 are critical for IL-21-mediated gene regulation. Expression of some genes, including Tbx21 and Ifng, was differentially regulated by STAT1 and STAT3, and interestingly, ChIP-Seq analysis showed that STAT3 binding at Tbx21 and Ifng loci was attenuated in Stat1-deficient cells. Moreover, opposing actions of STAT1 and STAT3 on IFN- expression in CD4+ T cells were demonstrated in vivo during chronic lymphocytic choriomeningitis (LCMV) infection. Finally, IL-21-mediated induction of STAT1 phosphorylation, as well as IFNG and TBX21 expression, were higher in CD4+ T cells from patients with autosomal dominant hyper-IgE syndrome (AD-HIES), which is caused by STAT3 deficiency. These data indicate an interplay between STAT1 and STAT3 in fine-tuning IL-21 actions.
Project description:Transcription factor recruitment to genomic sites of action is primarily due to direct protein:DNA interactions. The subsequent recruitment of co-regulatory complexes leads to either transcriptional activation or repression. In contrast to this canonical scheme, some transcription factors such as the glucocorticoid receptor (GR) behave as transcriptional repressors when recruited to target genes through protein tethering. We have investigated the genome-wide prevalence of tethering between GR and Stat3 and found non-reciprocal interactions, namely that GR tethering to DNA-bound Stat3 results in transcriptional repression whereas Stat3 tethering to GR results in synergism. Further, other schemes of GR and Stat3 co-recruitment to regulatory modules result in transcriptional synergism, including neighbouring and composite binding sites. The results indicate extensive transcriptional interactions between Stat3 and GR; further, they provide a genome-wide assessment of transcriptional regulation by tethering and a molecular basis for integration of signals mediated by GR and Stats in health and disease. ChIP-seq analysis of Stat3 and GR binding sites in pituitary corticotroph AtT-20 cell model. Five independant ChIPs were pooled prior library preparation for each contitions: STAT3 (LIF), STAT3 (Dex+LIF), GR (Dex+LIF), GR (Dex) and control IgG.
Project description:The transcription factor STAT5 plays a critical role in B cell Acute Lymphoblastic Leukemia (B-ALL). How STAT5 mediates this effect is unclear. Here we demonstrate that STAT5 activation cooperates with defects in the pre-BCR signaling components Blnk, Btk, Prkcb, Nfkb1, and Ikzf1 to initiate B-ALL. STAT5 antagonizes NFkB and IKAROS by opposing regulation of shared target genes. STAT5 binding was enriched at super-enhancers, which were associated with an opposing network of transcription factors, including PAX5, EBF1, PU.1, IRF4, and IKAROS. Patients with high ratios of active STAT5 to NFκB or IKAROS have more aggressive disease. Our studies illustrate that an imbalance of two opposing transcriptional programs drive B-ALL, and suggest that restoring the balance of these pathways may inhibit B-ALL.
Project description:The transcription factor STAT5 plays a critical role in B cell acute lymphoblastic leukemia (B-ALL). How STAT5 mediates this effect is unclear. Here we demonstrate that STAT5 activation cooperates with defects in the pre-BCR signaling components encoded by Blnk, Btk, Prkcb, Nfkb1, and Ikzf1 to initiate B-ALL. STAT5 antagonizes NF-κB and IKAROS by opposing regulation of shared target genes. STAT5 binding was enriched at super-enhancers, which were associated with an opposing network of transcription factors, including PAX5, EBF1, PU.1, IRF4, and IKAROS. Patients with high ratios of active STAT5 to NF-κB or IKAROS have more aggressive disease. Our studies illustrate that an imbalance of two opposing transcriptional programs drive B-ALL, and suggest that restoring the balance of these pathways may inhibit B-ALL.