Project description: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: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: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.
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.
Project description:Cytokines interact with their receptors in the extracellular space to control immune responses. How the physicochemical properties of the extracellular space influence cytokine signaling is incompletely elucidated. Here, we show that the activity of interleukin (IL)-2, a critical cytokine in T cell immunity, is profoundly affected by pH, limiting IL-2 signaling within the acidic environment of tumors. Generation of lactic acid by tumors limits STAT5 activation, effector differentiation and anti-tumor immunity by CD8+ T cells and renders high-dose IL-2 therapy poorly effective. Directed evolution enabled selection of a pH-selective IL-2 mutein (Switch-2). Switch-2 binds the IL-2 receptor subunit IL-2Ra with higher affinity, triggers STAT5 activation and drives CD8+ T cell effector function more potently at acidic pH than at neutral pH. Consequently, high-dose Switch-2 therapy induces potent immune activation and tumor rejection with reduced on-target toxicity in normal tissues. Finally, we find that sensitivity to pH is a generalizable property of a diverse range of cytokines with broad relevance to immunity and immunotherapy in healthy and diseased tissues.
Project description:Cytokines interact with their receptors in the extracellular space to control immune responses. How the physicochemical properties of the extracellular space influence cytokine signaling is incompletely elucidated. Here, we show that the activity of interleukin (IL)-2, a critical cytokine in T cell immunity, is profoundly affected by pH, limiting IL-2 signaling within the acidic environment of tumors. Generation of lactic acid by tumors limits STAT5 activation, effector differentiation and anti-tumor immunity by CD8+ T cells and renders high-dose IL-2 therapy poorly effective. Directed evolution enabled selection of a pH-selective IL-2 mutein (Switch-2). Switch-2 binds the IL-2 receptor subunit IL-2Ra with higher affinity, triggers STAT5 activation and drives CD8+ T cell effector function more potently at acidic pH than at neutral pH. Consequently, high-dose Switch-2 therapy induces potent immune activation and tumor rejection with reduced on-target toxicity in normal tissues. Finally, we find that sensitivity to pH is a generalizable property of a diverse range of cytokines with broad relevance to immunity and immunotherapy in healthy and diseased tissues.
Project description:In breast cancer, interactions between tumor cells and surrounding stromal cells, such as macrophages, are critical for tumor growth, progression, and therapeutic response. Recent studies have highlighted the complex nature and heterogeneous populations of macrophages associated with both tumor promoting and tumor inhibiting phenotypes. Identifying the specific signaling pathways that regulate macrophage function within the tumor microenvironment will lead to new approaches that suppress tumor promoting functions while enhancing their anti-tumor functions. We demonstrated STAT5 (signal transducer and activator of transcription 5) is robustly activated in tumor-associated macrophages and that granulocyte-macrophage colony stimulating factor (GM-CSF) is a major cytokine stimulating this pathway. To define impacts of GM-CSF/STAT5 on macrophage function, we used in vitro and in vivo models to demonstrate that STAT5 has a significant role in stimulating expression profiles in macrophages consistent with an anti-tumor, adaptive immune response. Our results also indicate that loss of STAT5 in the myeloid lineage leads to enhanced metastatic disease. These findings reveal that disrupted STAT5 signaling in tumor-associated macrophages supports tumor progression, which suggests STAT5 may regulate anti-tumor macrophage function. Understanding how to enhance the anti-tumor capacity of macrophages will be vital in developing effective treatment strategies for patients with aggressive breast cancer.