Critical Role of STAT5 Transcription Factor Tetramerization for Cytokine Responses and Normal Immune Function
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ABSTRACT: This SuperSeries is composed of the following subset Series: GSE36882: Critical Role of STAT5 Transcription Factor Tetramerization for Cytokine Responses and Normal Immune Function (ChIP-Seq and RNA-Seq) GSE36888: Critical Role of STAT5 Transcription Factor Tetramerization for Cytokine Responses and Normal Immune Function (RNA) Refer to individual Series
Project description:Cytokine-activated STAT proteins dimerize and bind to high-affinity motifs, and N-terminal domain-mediated oligomerization of dimers allows tetramer formation and binding to low-affinity tandem motifs, but the functions of dimers versus tetramers are unknown. We generated Stat5a and Stat5b double knock-in (DKI) N-domain mutant mice that form dimers but not tetramers, identified cytokine-regulated genes whose expression required STAT5 tetramers, and defined consensus motifs for dimers versus tetramers. Whereas Stat5- deficient mice exhibited perinatal lethality, DKI mice were viable, indicating that STAT5 dimers were sufficient for survival. Nevertheless, STAT5 DKI mice had fewer CD4+CD25+ T cells, NK cells, and CD8+ T cells, with impaired cytokine-induced proliferation and homeostatic proliferation of CD8+ T cells. DKI CD8+ T cell proliferation following viral infection was diminished and DKI Treg cells did not efficiently control colitis. Thus, tetramerization of STAT5 is dispensable for survival but is critical for cytokine responses and normal immune function. Genome-wide mapping of STAT5A,STAT5B binding in mouse WT and DKI T cells (cultured with or without IL-2 for 1 hr) was conducted. RNA-Seq is conducted in mouse CD8+ T cells (WT and DKI, non-treated or treated with IL-2/IL-15 for 4 hr, 24 hr, 48 hr and 72 hr)
Project description:Interferon regulatory factor 4 (IRF4) is an IRF family transcription factor with critical roles in lymphoid development and in regulating the immune response. IRF4 binds DNA weakly owing to a carboxy-terminal auto-inhibitory domain, but cooperative binding with factors such as PU.1 or SPIB in B cells increases binding affinity, allowing IRF4 to regulate genes containing ETS–IRF composite elements (EICEs; 5'-GGAAnnGAAA-3'). Here we show that in mouse CD4+ T cells, where PU.1/SPIB expression is low, and in B cells, where PU.1 is well expressed, IRF4 unexpectedly can cooperate with activator protein-1 (AP1) complexes to bind to AP1–IRF4 composite (5'-TGAnTCA/GAAA-3') motifs that we denote as AP1–IRF composite elements (AICEs). Moreover, BATF–JUN family protein complexes cooperate with IRF4 in binding to AICEs in pre-activated CD4+ T cells stimulated with IL-21 and in TH17 differentiated cells. Importantly, BATF binding was diminished in Irf4-/- T cells and IRF4 binding was diminished in Batf-/- T cells, consistent with functional cooperation between these factors. Moreover, we show that AP1 and IRF complexes cooperatively promote transcription of the Il10 gene, which is expressed in TH17 cells and potently regulated by IL-21. These findings reveal that IRF4 can signal via complexes containing ETS or AP1 motifs depending on the cellular context, thus indicating new approaches for modulating IRF4-dependent transcription. Genome-wide transcription factors mapping and binding of IRF4, BATF, IRF8, STAT3, JUN etc in WT, Irf4-/- and Batf-/- mice in different cell types (B cells, CD4+ T cells and TH17 cells) cultured with or without IL-21 was conducted. RNA-Seq is conducted in mouse B cells, CD4+ T cells, TH1/TH2/TH9/TH17/Treg.
Project description:Interleukin 9 (IL-9) is a γc-family cytokine that is highly produced by T-helper 9 (Th9) cells and regulates a range of immune responses, including allergic inflammation. Here we show that IL-2–JAK3–STAT5 signaling is required for Th9 differentiation, with critical STAT5 binding sites in the Il9 (the gene encoding IL-9) promoter. IL-2 also inhibited B cell lymphoma 6 (BCL6) expression, and over- expression of BCL6 impaired Th9 differentiation. In contrast to IL-2, IL-21 induced BCL6 and diminished IL-9 expression in wild-type but not Bcl6−/− cells, whereas Th9 differentiation was increased in Il21−/− or Il21r−/− T cells. Interestingly, BCL6 bound in proximity to many STAT5 and STAT6 binding sites, including at the Il9 promoter. Moreover, there was increased BCL6 and decreased STAT binding at this site in cells treated with blocking antibodies to IL-2 and the IL-2 receptor, suggesting a possible BCL6–STAT5 binding competition that influences IL-9 production. BCL6 binding was also increased when cells were Th9-differentiated in the presence of IL-21. Thus, our data reveal not only direct IL-2 effects via STAT5 at the Il9 gene, but also opposing actions of IL-2 and IL-21 on BCL6 expression, with increased BCL6 expression inhibiting IL-9 production. These data suggest a model in which increasing BCL6 expression decreases efficient Th9 differentiation, indicating possible distinctive approaches for controlling this process. Genome-wide transcription factors mapping and binding of STAT5B and STAT6 in mouse polarized Th9 cells treated with or without blocking antibodies to IL-2 (anti-IL-2). RNA-Seq is conducted in WT and Il2-/- mice.
Project description:Cytokine-activated STAT proteins dimerize and bind to high-affinity motifs, and N-terminal domain-mediated oligomerization of dimers allows tetramer formation and binding to low-affinity tandem motifs, but the functions of dimers versus tetramers are unknown. We generated Stat5a and Stat5b double knock-in (DKI) N-domain mutant mice that form dimers but not tetramers, identified cytokine-regulated genes whose expression required STAT5 tetramers, and defined consensus motifs for dimers versus tetramers. Whereas Stat5- deficient mice exhibited perinatal lethality, DKI mice were viable, indicating that STAT5 dimers were sufficient for survival. Nevertheless, STAT5 DKI mice had fewer CD4+CD25+ T cells, NK cells, and CD8+ T cells, with impaired cytokine-induced proliferation and homeostatic proliferation of CD8+ T cells. DKI CD8+ T cell proliferation following viral infection was diminished and DKI Treg cells did not efficiently control colitis. Thus, tetramerization of STAT5 is dispensable for survival but is critical for cytokine responses and normal immune function. T cells were extracted from spleen of wt and STAT5 double knocked in mice, and treated with IL-2. The cells were collected from 0h (without treatment), 2h, 6h and 17h, and chipped on Affy mouse 430 2.0 arrays.
Project description:The transcription factor STAT5 is fundamental to the mammalian immune system. However, the relationship between its two paralogs, STAT5A and STAT5B, and the extent to which they are functionally distinct, remains controversial. We addressed this longstanding question in primary CD4+ 'helper' T cells, the principal orchestrators of adaptive immunity. Using a combination of genetic and genomic approaches, we demonstrate that, although both influence regulatory (Treg) and effector T cell responses, and control many of the same genes, they are not functionally equivalent and, in fact, only the latter is required for immunological tolerance. Differences in genomic distribution and transcriptomic output support the conclusion that STAT5B is dominant and, surprisingly, point towards relative abundance (i.e. paralog dose), rather than unique functional capabilities, as the principal distinguishing feature. Collectively, our data provide a unifying model for the discrete and redundant activities of STAT5A and STAT5B, establishing that asymmetrical expression underlies paralog specificity (or dominance) in the face of widespread structural homology. This dataset includes 55 individual samples of transcriptome or STAT5 distibution data from cytokine treated CD4+T cells. Each culture condition includes at least 2 biological replicates per genotype.
Project description:Interleukin-15 (IL-15) and IL-2 possess distinct immunological functions despite both signaling through IL-2Rβ and the common cytokine receptor γ-chain, γc, We find that in the IL-15/IL-15Rα/IL-2Rβ/γc quaternary complex structure, IL-15 heterodimerizes IL-2Rβ and γc identically to the IL-2/IL-2Rα/IL-2Rβ/γc complex, despite differing receptor-binding chemistries. IL-15Rα dramatically increases the affinity of IL-15 for IL-2Rβ, and this allostery is required for IL-15 trans-signaling versus IL-2 cis-signaling. Consistent with the identical IL-2Rβ/γc dimer geometry, IL-2 and IL-15 exhibited similar signaling properties in lymphocytes, with any differences resulting from disparate receptor affinities. Thus, IL-15 and IL-2 induce similar signals, and the cytokine-specificity of IL-2Rα versus IL-15Rα determines cellular responsiveness. These results provide important new insights for specific development of IL-15- versus IL-2-based immunotherapeutics. RNA-Seq is conducted in mouse CD8+ T cells, not treated or treated with IL2 or IL15 for indicated concentrations (1nM or 500nM) and times (4hr or 24hr).
Project description:Interleukin-2 (IL-2) is a pleiotropic cytokine that regulates lymphocyte function by signaling through heterodimerization of the IL-2Rβ and γc receptor subunits. Previously, we engineered an IL-2 “superkine” (H9) with enhanced affinity for IL-2Rβ. Here, we describe next-generation IL-2 variants that function as “receptor signaling clamps.” They retain high-affinity for IL-2Rβ, thereby inhibiting binding of endogenous IL-2, but their engagement of γc is weakened, thereby attenuating IL-2Rβ-γc heterodimerization. These IL-2 analogues act as partial agonists and can differentially affect lymphocytes poised at distinct activation thresholds. Moreover, one of these variants potently antagonized IL-2 and IL-15 signaling and function better than blocking antibodies against IL-2Rα or IL-2Rβ. Furthermore, this mutein prolonged survival in a model of graft versus host disease and blocked spontaneous proliferation of smoldering adult T-cell leukemia (ATL) T cells ex vivo. This receptor-clamping approach may be a general mechanism-based strategy for engineering cytokine partial agonists for therapeutic immunomodulation. Genome-wide transcription factors binding of STAT5 and mRNA-Sequencing of gene expression profiles in human pre-activated CD8+ T cells.
Project description:Establishment and differentiation of mammary alveoli during pregnancy are controlled by prolactin through the transcription factor STAT5. As pregnancy progresses mammary signature genes are activated in a defined temporal order, which coincides with the recruitment of STAT5 to respective regulatory sequences. This study addressed the question whether the methyltransferase and transcriptional co-activator EZH2 controls the differentiation clock of mammary epithelium. Ablation of Ezh2 from mammary stem cells resulted in precocious differentiation of alveolar epithelium during pregnancy and the activation of mammary-specific STAT5 target genes. This coincided with enhanced occupancy by STAT5, EZH1 and Pol II to these loci. Limited activation of differentiation-specific genes was also observed in mammary epithelium lacking both EZH2 and STAT5, suggesting a modulating but not mandatory role for STAT5. Notably, loss of EZH2 did not result in overt changes in genome-wide and gene-specific H3K27me3 patterns, suggesting that enhanced EZH1 recruitment can compensate for the loss of EZH2. Differentiated mammary epithelia failed to form in the combined absence of EZH1 and EZH2. Transplantation experiments failed to demonstrate a role for EZH2 in the biology of mammary stem and progenitor cells. In summary, while EZH1 and EZH2 serve redundant functions in the establishment of H3K27me3 and formation of mammary alveoli, the presence of EZH2 is required to obtain controlled temporal differentiation of mammary epithelium. mRNA-seq in WT;MMTV-Cre (Control) at p13 and p18, E1-/- (E1KO), Ezh2f/f;MMTV-Cre(E2KO), Stat5f/f;MMTV-Cre(S5KO), and Ezh2f/f;Stat5f/f;MMTV-Cre (E2S5DKO) at p13 mammary tissues. ChIP-seq for H3K27me3, STAT5, EZH1, EZH2 and PolII in mammary tissues at p13
Project description:We performed ChIP-seq on a complex developing tissue (the spinal cord) at mouse embryonic day 12.5. Genome-wide binding sites of Mash1 were generated. ChIP-seq of Mash1/Ascl1 in a heterogeneous tissue.
Project description:The c-Myc HLH-bZIP protein has been implicated in physiological or pathological growth, proliferation, apoptosis, metabolism and differentiation at the cellular, tissue or organismal levels via regulation of numerous target genes. In part due to the incomplete inventory and functional accounting of Myc’s targets, no principle unifies Myc action. To relate the dynamics of Myc-binding with target expression and function in a system where Myc-levels are temporally and physiologically regulated, the transcriptomes and the genome-wide distributions of Myc, RNA polymerase II and chromatin modifications were compared during lymphocyte activation and in ES cells. A remarkably simple rule emerged from this quantitative analysis: Myc is not an on-off switch, but is a non-linear amplifier of expression, acting universally at active genes, except for immediate early genes that are strongly induced before Myc. This rule of Myc action explains the vast majority of Myc biology observed in literature. Quiescent B-cells (B0) were treated with lipopolysaccharide (LPS) for 4 hrs (B4), and resting T-cells (T0) were activated with conA for 4 hrs (T4) and for 14 hrs (T14). Following treatments, RNA was harvested and chromatin was prepared at these time points. The chromatin was immunoprecipitated using anti-EGFP antibodies and analyzed by ChIP-seq.