Project description:IL-21 induces B cell activation, and differentiation into antibody-secreting plasmablasts in vitro. This process is abolished by loss-of function mutations in STAT3 We used microarrays to identify genes that are induced by IL-21 in a STAT3-dependent manner
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:IL-21 induces B cell activation, and differentiation into antibody-secreting plasmablasts in vitro. This process is abolished by loss-of function mutations in STAT3 We used microarrays to identify genes that are induced by IL-21 in a STAT3-dependent manner Sort-purified naïve B cells from four healthy donors and three patients with AD-HIES due to heterozygous STAT3 mutations were cultured for four days with CD40L in the presence or absence of IL-21 (50ng/ml). After four days, RNA was extracted from the harvested cells and the genetic profile was analysed by microarray.
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-1β production requires TLR-mediated NF-κB-dependent Il1b gene induction, followed by caspase-containing inflammasome-mediated processing of pro-IL-1β. Here we show that IL-21 unexpectedly induces IL-1β production in conventional dendritic cells (cDCs) via a STAT3-dependent but NF-κB-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-1β 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-1β 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-1β via a non-canonical pathway and provide evidence for its importance in vivo.
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.
Project description:Transcriptional profiling of Homo sapiens inflammatory skin diseases (whole skin biospies): Psoriasis (Pso), vs Atopic Dermatitis (AD) vs Lichen planus (Li), vs Contact Eczema (KE), vs Healthy control (KO) In recent years, different genes and proteins have been highlighted as potential biomarkers for psoriasis, one of the most common inflammatory skin diseases worldwide. However, most of these markers are not psoriasis-specific but also found in other inflammatory disorders. We performed an unsupervised cluster analysis of gene expression profiles in 150 psoriasis patients and other inflammatory skin diseases (atopic dermatitis, lichen planus, contact eczema, and healthy controls). We identified a cluster of IL-17/TNFα-associated genes specifically expressed in psoriasis, among which IL-36γ was the most outstanding marker. In subsequent immunohistological analyses IL-36γ was confirmed to be expressed in psoriasis lesions only. IL-36γ peripheral blood serum levels were found to be closely associated with disease activity, and they decreased after anti-TNFα-treatment. Furthermore, IL-36γ immunohistochemistry was found to be a helpful marker in the histological differential diagnosis between psoriasis and eczema in diagnostically challenging cases. These features highlight IL-36γ as a valuable biomarker in psoriasis patients, both for diagnostic purposes and measurement of disease activity during the clinical course. Furthermore, IL-36γ might also provide a future drug target, due to its potential amplifier role in TNFα- and IL-17 pathways in psoriatic skin inflammation. In recent years, different genes and proteins have been highlighted as potential biomarkers for psoriasis, one of the most common inflammatory skin diseases worldwide. However, most of these markers are not psoriasis-specific but also found in other inflammatory disorders. We performed an unsupervised cluster analysis of gene expression profiles in 150 psoriasis patients and other inflammatory skin diseases (atopic dermatitis, lichen planus, contact eczema, and healthy controls). We identified a cluster of IL-17/TNFα-associated genes specifically expressed in psoriasis, among which IL-36γ was the most outstanding marker. In subsequent immunohistological analyses IL-36γ was confirmed to be expressed in psoriasis lesions only. IL-36γ peripheral blood serum levels were found to be closely associated with disease activity, and they decreased after anti-TNFα-treatment. Furthermore, IL-36γ immunohistochemistry was found to be a helpful marker in the histological differential diagnosis between psoriasis and eczema in diagnostically challenging cases. These features highlight IL-36γ as a valuable biomarker in psoriasis patients, both for diagnostic purposes and measurement of disease activity during the clinical course. Furthermore, IL-36γ might also provide a future drug target, due to its potential amplifier role in TNFα- and IL-17 pathways in psoriatic skin inflammation.
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.