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) 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:IL-6 and IL-27 have antagonistic and overlapping functions, signal through a shared receptor subunit and employ the same downstream STAT proteins. To evaluate the degree of specificity and redundancy for these cytokines, we quantified global transcriptomic changes induced by the two cytokines and determined the relative contributions of STAT1 and STAT3 using genetic models and ChIP-seq. We found a high degree of overlap of the transcriptomes induced by IL-6 and IL-27 and extremely few examples in which the cytokines acted in opposition. Using STAT deficient cells and T cells from patients with gain-of-function STAT1 mutations, we show that STAT3 was responsible for the overall transcriptional output driven by both cytokines, whereas STAT1 was the driver of cytokine specificity. STAT1 did not compensate for the lack STAT3; on the contrary, much of STAT1 binding to chromatin was STAT3 dependent. Thus, STAT1 shapes the specific cytokine signature superimposed upon STAT3’s action. Integrated analysis of transcriptome and transcription factor binding data from cytokine treated CD4+T cells
Project description:Qi2013 - IL-6 and IFN crosstalk model
(non-competitive)
This model
[BIOMD0000000543]
describes the crosstalk between IFN-gamma and IL-6 induced
signalling; it aims to outline mechanisms and factors that may
control the interaction between both signalling pathways,
discussing a role of heterodimer formation in signalling
dysfunction.
To account for the possibility of different IFNR and gp130
binding sites for STAT1 and STAT3, model 1
[BIOMD0000000543]
assumes that there is no competition between STAT1 and STAT3 for
the receptor complexes (includes two extra reactions).
The reverse of this is true in model 2
[BIOMD0000000544]
where it generally is assumed that there is competition between
STAT1 and STAT3 for the receptor complexes.
This model is described in the article:
Elucidating the crosstalk
mechanism between IFN-gamma and IL-6 via mathematical
modelling.
Qi YF, Huang YX, Wang HY, Zhang Y,
Bao YL, Sun LG, Wu Y, Yu CL, Song ZB, Zheng LH, Sun Y, Wang GN,
Li YX.
BMC Bioinformatics 2013; 14: 41
Abstract:
BACKGROUND: Interferon-gamma (IFN-gamma) and interleukin-6
(IL-6) are multifunctional cytokines that regulate immune
responses, cell proliferation, and tumour development and
progression, which frequently have functionally opposing roles.
The cellular responses to both cytokines are activated via the
Janus kinase/signal transducer and activator of transcription
(JAK/STAT) pathway. During the past 10 years, the crosstalk
mechanism between the IFN-gamma and IL-6 pathways has been
studied widely and several biological hypotheses have been
proposed, but the kinetics and detailed crosstalk mechanism
remain unclear. RESULTS: Using established mathematical models
and new experimental observations of the crosstalk between the
IFN-gamma and IL-6 pathways, we constructed a new crosstalk
model that considers three possible crosstalk levels: (1) the
competition between STAT1 and STAT3 for common receptor docking
sites; (2) the mutual negative regulation between SOCS1 and
SOCS3; and (3) the negative regulatory effects of the formation
of STAT1/3 heterodimers. A number of simulations were tested to
explore the consequences of cross-regulation between the two
pathways. The simulation results agreed well with the
experimental data, thereby demonstrating the effectiveness and
correctness of the model. CONCLUSION: In this study, we
developed a crosstalk model of the IFN-gamma and IL-6 pathways
to theoretically investigate their cross-regulation mechanism.
The simulation experiments showed the importance of the three
crosstalk levels between the two pathways. In particular, the
unbalanced competition between STAT1 and STAT3 for IFNR and
gp130 led to preferential activation of IFN-gamma and IL-6,
while at the same time the formation of STAT1/3 heterodimers
enhanced preferential signal transduction by sequestering a
fraction of the activated STATs. The model provided a good
explanation of the experimental observations and provided
insights that may inform further research to facilitate a
better understanding of the cross-regulation mechanism between
the two pathways.
This model is hosted on
BioModels Database
and identified by:
BIOMD0000000543.
To cite BioModels Database, please use:
BioModels Database:
An enhanced, curated and annotated resource for published
quantitative kinetic models.
To the extent possible under law, all copyright and related or
neighbouring rights to this encoded model have been dedicated to
the public domain worldwide. Please refer to
CC0
Public Domain Dedication for more information.
Project description:Qi2013 - IL-6 and IFN crosstalk model
This model
[BIOMD0000000544]
describes the crosstalk between IFN-gamma and IL-6 induced
signalling; it aims to outline mechanisms and factors that may
control the interaction between both signalling pathways,
discussing a role of heterodimer formation in signalling
dysfunction.
To account for the possibility of different IFNR and gp130
binding sites for STAT1 and STAT3, model 1
[BIOMD0000000543]
assumes that there is no competition between STAT1 and STAT3 for
the receptor complexes (includes two extra reactions).
The reverse of this is true in model 2
[BIOMD0000000544]
where it generally is assumed that there is competition between
STAT1 and STAT3 for the receptor complexes.
This model is described in the article:
Elucidating the crosstalk
mechanism between IFN-gamma and IL-6 via mathematical
modelling.
Qi YF, Huang YX, Wang HY, Zhang Y,
Bao YL, Sun LG, Wu Y, Yu CL, Song ZB, Zheng LH, Sun Y, Wang GN,
Li YX.
BMC Bioinformatics 2013; 14: 41
Abstract:
BACKGROUND: Interferon-gamma (IFN-gamma) and interleukin-6
(IL-6) are multifunctional cytokines that regulate immune
responses, cell proliferation, and tumour development and
progression, which frequently have functionally opposing roles.
The cellular responses to both cytokines are activated via the
Janus kinase/signal transducer and activator of transcription
(JAK/STAT) pathway. During the past 10 years, the crosstalk
mechanism between the IFN-gamma and IL-6 pathways has been
studied widely and several biological hypotheses have been
proposed, but the kinetics and detailed crosstalk mechanism
remain unclear. RESULTS: Using established mathematical models
and new experimental observations of the crosstalk between the
IFN-gamma and IL-6 pathways, we constructed a new crosstalk
model that considers three possible crosstalk levels: (1) the
competition between STAT1 and STAT3 for common receptor docking
sites; (2) the mutual negative regulation between SOCS1 and
SOCS3; and (3) the negative regulatory effects of the formation
of STAT1/3 heterodimers. A number of simulations were tested to
explore the consequences of cross-regulation between the two
pathways. The simulation results agreed well with the
experimental data, thereby demonstrating the effectiveness and
correctness of the model. CONCLUSION: In this study, we
developed a crosstalk model of the IFN-gamma and IL-6 pathways
to theoretically investigate their cross-regulation mechanism.
The simulation experiments showed the importance of the three
crosstalk levels between the two pathways. In particular, the
unbalanced competition between STAT1 and STAT3 for IFNR and
gp130 led to preferential activation of IFN-gamma and IL-6,
while at the same time the formation of STAT1/3 heterodimers
enhanced preferential signal transduction by sequestering a
fraction of the activated STATs. The model provided a good
explanation of the experimental observations and provided
insights that may inform further research to facilitate a
better understanding of the cross-regulation mechanism between
the two pathways.
This model is hosted on
BioModels Database
and identified by:
BIOMD0000000544.
To cite BioModels Database, please use:
BioModels Database:
An enhanced, curated and annotated resource for published
quantitative kinetic models.
To the extent possible under law, all copyright and related or
neighbouring rights to this encoded model have been dedicated to
the public domain worldwide. Please refer to
CC0
Public Domain Dedication for more information.
Project description:Interleukin-21 (IL-21) is a pleiotropic cytokine that induces expression of transcription factor BLIMP1 (encoded by Prdm1), which regulates plasma cell differentiation and T cell homeostasis. We identified an IL-21 response element downstream of Prdm1 that binds the transcription factors STAT3 and IRF4, which are required for optimal Prdm1 expression. Genome-wide ChIP-Seq mapping of STAT3- and IRF4-binding sites showed that most regions with IL-21-induced STAT3 binding also bound IRF4 in vivo, and furthermore, revealed that the noncanonical TTCnnnTAA GAS motif critical in Prdm1 was broadly used for STAT3 binding. Comparing genome-wide expression array data to binding sites revealed that most IL-21-regulated genes were associated with combined STAT3-IRF4 sites rather than pure STAT3 sites. Correspondingly, ChIP-Seq analysis of Irf4_/_ T cells showed greatly diminished STAT3 binding after IL-21 treatment, and Irf4_/_ mice showed impaired IL- 21-induced Tfh cell differentiation in vivo. These results reveal broad cooperative gene regulation by STAT3 and IRF4. Affymetrix expression data: Prepare CD4+ T cells from spleen. CD4+ T cells were preactivated, rested, and treated with IL-21 for 1, 6, and 24 hours. ChIP-seq data: Profiling of IRF4 and Stat3 binding with and without IL-21 stimulation in wild type and IRF4 KO mice.
Project description:The canonical pathway for IL-1? production requires TLR-mediated NF-?B-dependent Il1b gene induction, followed by caspase-containing inflammasome-mediated processing of pro-IL-1?. Here we show that IL-21 unexpectedly induces IL-1? production in conventional dendritic cells (cDCs) via a STAT3-dependent but NF-?B-independent pathway. IL-21 does not induce Il1b expression in CD4+ T cells, with differential histone marks present in these cells versus cDCs. IL-21-induced IL-1? processing in cDCs does not require caspase-1 or caspase-8 but depends on IL-21-mediated death and activation of serine protease(s). Moreover, STAT3-dependent IL-1? expression in cDCs at least partially explains the IL-21-mediated pathologic response occurring during infection with Pneumonia Virus of Mice. These results demonstrate lineage-restricted IL-21-induced IL-1? via a non-canonical pathway and provide evidence for its importance in vivo. Genome-wide transcription factors mapping and binding of STAT3, H3K4me3, H3K27me, H3K4me1, H3K27ac in mouse CD4+ T cells and dendritic cells in WT and Stat3-/- mice. RNA-Seq is performed in mouse CD4+ T cells and dendritic cells in WT mice, with or without indicated cytokines.
Project description:Naïve and activated T-cells has a different response to antigenic challenge. We examine whether a cytokine like IL-6 induces different responses through the Jak-STAT pathway to affect the functional characteristics of a given CD4 T‑cell subset. We isolated naïve and effector memory (Tem) CD4 T-cells to investigated STAT1 and STAT3 binding after 1-hour treatment with 20ng/ml IL-6 in the presence of anti-CD3/CD28.
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