Discrete Roles of STAT4 and STAT6 Transcription Factors in Tuning Epigenetic Modifications and Transcription during Helper T Cell Differentiation (gene expression)
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ABSTRACT: Signal transducer and activator of transcription 4 (STAT4) and STAT6 are key factors in the specification of helper T cells; however, their direct roles in driving differentiation are not well understood. Using chromatin immunoprecipitation and massive parallel sequencing, we quantitated the full complement of STAT-bound genes, concurrently assessing global STAT-dependent epigenetic modifications and gene transcription using cells from cognate STAT-deficient mice. STAT4 and STAT6 each bound over 4000 genes with distinct binding motifs. Both played critical roles in maintaining chromatin configuration and transcription of a core subset of genes through the combination of different epigenetic patterns. Globally, STAT4 had a more dominant role in promoting active epigenetic marks, whereas STAT6 had a more prominent role in antagonizing repressive marks. Clusters of genes negatively regulated by STATs were also identified, highlighting previously unappreciated repressive roles. Therefore, STAT4 and STAT6 play wide regulatory roles in T helper specification. The roles of STAT proteins to shape T helper cell phenotype was investigated by comparing DNA binding profiles of STAT4 and STAT6 in Th1 and Th2 conditions. The functional outcome of STAT bindings was further evaluated by profiling histone epigenetic marks and gene expression changes between WT and STAT-deficient T cells in Th1 and Th2 conditions. Affymetrix Mouse Genome 430 2.0 Arrays were used to evaluate global gene expression.
Project description:Signal transducer and activator of transcription 4 (STAT4) and STAT6 are key factors in the specification of helper T cells; however, their direct roles in driving differentiation are not well understood. Using chromatin immunoprecipitation and massive parallel sequencing, we quantitated the full complement of STAT-bound genes, concurrently assessing global STAT-dependent epigenetic modifications and gene transcription using cells from cognate STAT-deficient mice. STAT4 and STAT6 each bound over 4000 genes with distinct binding motifs. Both played critical roles in maintaining chromatin configuration and transcription of a core subset of genes through the combination of different epigenetic patterns. Globally, STAT4 had a more dominant role in promoting active epigenetic marks, whereas STAT6 had a more prominent role in antagonizing repressive marks. Clusters of genes negatively regulated by STATs were also identified, highlighting previously unappreciated repressive roles. Therefore, STAT4 and STAT6 play wide regulatory roles in T helper specification. The roles of STAT proteins to shape T helper cell phenotype was investigated by comparing DNA binding profiles of STAT4 and STAT6 in Th1 and Th2 conditions. The functional outcome of STAT bindings was further evaluated by profiling histone epigenetic marks and gene expression changes between WT and STAT-deficient T cells in Th1 and Th2 conditions.
Project description:This SuperSeries is composed of the following subset Series: GSE22081: Discrete Roles of STAT4 and STAT6 Transcription Factors in Tuning Epigenetic Modifications and Transcription during Helper T Cell Differentiation (gene expression) GSE22104: Discrete Roles of STAT4 and STAT6 Transcription Factors in Tuning Epigenetic Modifications and Transcription during Helper T Cell Differentiation (ChIP-Seq) Refer to individual Series
Project description:Signal transducer and activator of transcription 4 (STAT4) and STAT6 are key factors in the specification of helper T cells; however, their direct roles in driving differentiation are not well understood. Using chromatin immunoprecipitation and massive parallel sequencing, we quantitated the full complement of STAT-bound genes, concurrently assessing global STAT-dependent epigenetic modifications and gene transcription using cells from cognate STAT-deficient mice. STAT4 and STAT6 each bound over 4000 genes with distinct binding motifs. Both played critical roles in maintaining chromatin configuration and transcription of a core subset of genes through the combination of different epigenetic patterns. Globally, STAT4 had a more dominant role in promoting active epigenetic marks, whereas STAT6 had a more prominent role in antagonizing repressive marks. Clusters of genes negatively regulated by STATs were also identified, highlighting previously unappreciated repressive roles. Therefore, STAT4 and STAT6 play wide regulatory roles in T helper specification.
Project description:Signal transducer and activator of transcription 4 (STAT4) and STAT6 are key factors in the specification of helper T cells; however, their direct roles in driving differentiation are not well understood. Using chromatin immunoprecipitation and massive parallel sequencing, we quantitated the full complement of STAT-bound genes, concurrently assessing global STAT-dependent epigenetic modifications and gene transcription using cells from cognate STAT-deficient mice. STAT4 and STAT6 each bound over 4000 genes with distinct binding motifs. Both played critical roles in maintaining chromatin configuration and transcription of a core subset of genes through the combination of different epigenetic patterns. Globally, STAT4 had a more dominant role in promoting active epigenetic marks, whereas STAT6 had a more prominent role in antagonizing repressive marks. Clusters of genes negatively regulated by STATs were also identified, highlighting previously unappreciated repressive roles. Therefore, STAT4 and STAT6 play wide regulatory roles in T helper specification.
Project description:Follicular helper T (Tfh) cells comprise an important subset of helper T cells; however, their relationship with other helper lineages is incompletely understood. Herein, we show IL-12 acting via signal transducer and activator of transcription 4 (STAT4) induced both Il21 and Bcl6 genes, generating cells with features of both Tfh and Th1 cells. However, STAT4 also induced T-bet. Using ChIP-seq, we defined the genome-wide targets of T-bet and found that it repressed Bcl6 and other markers of Tfh cells, thereby attenuating the nascent Tfh-like phenotype in the late phase of Th1 specification. Finally, Tfh-like T cells were rapidly generated following Toxoplasma gondii infection in mice, but T-bet constrained Tfh cells expansion and consequent germinal center formation and antibody production. Our data argue that Tfh and Th1 share a transitional stage through the signal mediated by STAT4, which promotes both phenotypes. However, T-bet represses Tfh functionalities, promoting full Th1 differentiation. The roles of STAT4 and T-bet to determine T helper cell fate were investigated by comparing DNA binding profiles of STAT4 and T-bet in Th1 conditions. The functional outcome was further evaluated by profiling DNase hypersensitivity sites and histone epigenetic marks between WT and STAT4-deficient or T-bet-deficient T cells in Th1 conditions.
Project description:Although lincRNAs are implicated in regulating gene expression in various tissues, little is known about lincRNA transcriptomes in the T cell lineages. Here we identify 1,524 lincRNAs in 42 T cell samples from early T cell progenitors to terminally differentiated T helper subsets. Our analysis revealed highly dynamic and cell-specific expression patterns of lincRNAs during T cell differentiation. Importantly, these lincRNAs are located in genomic regions enriched for protein-coding genes with immune-regulatory functions. Many of these transcripts are bound and regulated by the key T cell transcription factors, T-bet, GATA3, STAT4 and STAT6. We demonstrate that the lincRNA LincR-Ccr2-5'AS, together with GATA3, is an essential component of a regulatory circuit in Th2-specific gene expression. To obtain comprehensive profiles of lincRNA expression during the development and differentiation of T cell lineages, we purified CD4-CD8 double negative (DN) cells (DN1, DN2, DN3 and DN4), double positive (DP) cells (CD4+CD8+CD3low and CD4+CD8intCD69+), single positive (SP) CD4 and CD8 cells, and thymic-derived regulatory T cells (tTreg) from thymi of C57BL/6 mice. Additionally, we obtained Th1, Th2, Th17 and iTreg cells by in vitro differentiation of naM-CM-/ve CD4 T cells for a various length of time in culture (4 hrs, 8 hrs, 12 hrs, 24 hrs, 48 hrs, 72 hrs, 1 week, 2weeks). Total and/or polyadenylated RNAs from these cells was analyzed using RNA-Seq. To understand the regulation of lincRNAs by T cell master regulator T-bet, we compared the transcriptiomes between T-bet deficient Th1 cells and control Th1 cells. We did similar experiments and data analysis for STAT4 (Th1), GATA3 (Th2) and STAT6 (Th2). Finally, to address the funcation of a Th2-specifically expressed lincRNA, lincR-Ccr2-5'AS, we compared the transcriptomes between lincR-Ccr2-5'AS knockdown Th2 cells and control Th2 cells.
Project description:Differentiation of naive CD4 T cells into type 2 helper (Th2) cells is accompanied by chromatin remodeling and increased expression of a set of Th2-specific genes including those encoding Th2 cytokines. IL-4-mediated STAT6 activation induces high levels of transcription of GATA3, a master regulator of Th2 cell differentiation, and enforced expression of GATA3 induces Th2 cytokine expression. However, it remains unclear whether the expression of other Th2-specific genes is induced directly by GATA3. A genome-wide unbiased ChIP-seq analysis revealed that GATA3 bound to 1,279 genes selectively in Th2 cells, and 101 genes in both Th1 and Th2 cells. Simultaneously, we identified 26 highly Th2-specific STAT6-dependent inducible genes by a DNA microarray analysis-based three-step selection processes, and among them 17 genes showed GATA3 binding. We assessed dependency on GATA3 for the transcription of these 26 Th2-specific genes, and 10 genes showed increased transcription in a GATA3-dependent manner while 16 genes showed no significant responses. The transcription of the 16 GATA3-nonresponding genes was clearly increased by the introduction of an active form of STAT6, STAT6VT. Therefore, although GATA3 has been recognized as a master regulator of Th2 cell differentiation, many Th2-specific genes are not regulated by GATA3 itself but in collaboration with STAT6. Th1 and Th2 subsets are profiled for mRNA expression Examination of GATA3-binding and 3 different histone modifications in Th1 and Th2 cells.
Project description:Signaling pathways are intimately involved in cellular differentiation, allowing cells to respond to their environment by regulating gene expression. While enhancers are recognized as key elements that regulate selective gene expression, the interplay between signaling pathways and actively used enhancer elements is not clear. Here, we use CD4+ T cells as a model of differentiation, mapping the acquisition of cell-type-specific enhancer elements in T-helper 1 (Th1) and Th2 cells. Our data establish that STAT proteins have a major impact on the acquisition of lineage-specific enhancers and the suppression of enhancers associated with alternative cell fates. Transcriptome analysis further supports a functional role for enhancers regulated by STATs. Importantly, expression of lineage-defining master regulators in STAT-deficient cells fails to fully recover the chromatin signature of STAT-dependent enhancers. Thus, these findings point to a critical role of STATs as environmental sensors in dynamically molding the specialized enhancer architecture of differentiating cells. Active enhancer elements were defined as p300-high/H3K4me1-high. Using ChIP-seq, we mapped active enhancer landscapes of two CD4+ T helper cells, Th1 and Th2. To investigate the effect of STAT proteins on this landscape, we profiled active enhancers in the absence of STATs. Overall, STATs deficiency had a major impact on recruitment of p300. In addition, ectopic expression of master regulators T-bet and GATA3 in STAT-deficient cells failed to recover most active enhancers.
Project description:Antigen encounter directs CD4+ T cells to differentiate into T-helper or -regulatory cells. This process focuses the immune response on the invading pathogen and limits tissue damage. Mechanisms that govern -helper versus -regulatory fate remain poorly understood. Here, we show that the E3 ubiquitin ligase Cul5 determines fate selection in CD4+ T cells by regulating IL-4 receptor signaling. Mice lacking Cul5 in T cells developed enhanced Th2 and Th9 inflammation and pathophysiological features of atopic asthma upon allergen exposure. Following T cell activation, Cul5 formed a complex with CIS and pJak1. Loss of Cul5 function resulted in reduced ubiquitylation and increased stability of pJak1, elevated STAT6 activity, and a reduced threshold for IL-4 receptor signaling. In keeping with this, Cul5-deficient T cells deviated from Treg to Th9 differentiation in low IL-4 conditions. These data support that Cul5 promotes a tolerogenic T cell fate choice and reduces susceptibility to allergic asthma.
Project description:IL-10 production by Th17 cells is critical for limiting autoimmunity and inflammatory responses. Gene array analysis on Stat6 and T-bet double deficient Th17 cells identified the Th2 transcription factor c-Maf to be synergistically up-regulated by IL-6 plus TGFbeta, and associated with Th17 IL-10 production. Both c-Maf and IL-10 induction during Th17 polarization depended on Stat3, but not Stat6 or Stat1, and mechanistically differed from IL-10 regulation by Th2 or IL-27 signals. TGFbeta was also synergistic with IL-27 to induce c-Maf, and induced Stat1 independent IL-10 expression in contrast to IL-27 alone. Retroviral transduction of c-Maf was able to induce IL-10 expression in Stat6 deficient CD4 and CD8 T cells, and c-Maf directly transactivated IL-10 gene expression through binding to a MARE motif in the IL-10 promoter. Together, these data reveal a novel role for c-Maf in regulating T effector development, and suggest that TGFbeta may antagonize Th17 immunity by IL-10 production through c-Maf induction. Our recent studies showed that IL-6 combined with TGFbeta differed from IL-6 combined with IL-23 for IL-10 production and pathogenic activities in CD4 T cells deficient in Stat6 and T-bet, despite similar IL-17 production. We performed gene array analysis on Stat6 and T-bet double deficient cells. We rationalized that by comparing gene expression in cells treated with IL-6 plus TGFbeta versus TGFbeta alone, we would be able to identify genes specific for standard Th17 polarization, and responsible for both IL-17 and IL-10 expression. By next comparing gene expression in cells treated with IL-6 plus TGFbeta versus IL-6 plus IL-23, we could eliminate molecules involved solely in IL-17 regulation, and obtain genes specifically responsible for IL-10 regulation.