MicroRNA-155 confers encephalogenic potential to Th17 cells by promoting IL-23 responsiveness and effector gene expression
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ABSTRACT: We examined the role of miR-155 in differentiated Th17 cells during their induction of Experimental Autoimmune Encephalomyelitis (EAE). Using adoptive transfer experiments, we found that highly purified, MOG antigen specific Th17 cells lacking miR-155 are defective in their capacity to cause EAE. Gene expression profiling of purified miR-155-/- IL-17F+ Th17 cells identified a subset of effector genes that are dependent upon miR-155 for their proper expression through a mechanism involving repression of the transcription factor Ets1. Among the genes reduced in the absence of miR-155 was IL-23R, resulting in miR-155-/- Th17 cells being hypo-responsive to IL-23. Taken together, our study demonstrates a critical role for miR-155 in Th17 cells as they unleash autoimmune inflammation, and finds that this occurs through a signaling network involving miR-155, Ets1 and the clinically relevant IL-23-IL-23R pathway. two biological replicates of miR-155-/- CD4+ IL-17F RFP+ T cells compared to two biological replicates of miR-155+/+CD4+IL-17F RFP+ T cells (as a control).
Project description:We examined the role of miR-155 in differentiated Th17 cells during their induction of Experimental Autoimmune Encephalomyelitis (EAE). Using adoptive transfer experiments, we found that highly purified, MOG antigen specific Th17 cells lacking miR-155 are defective in their capacity to cause EAE. Gene expression profiling of purified miR-155-/- IL-17F+ Th17 cells identified a subset of effector genes that are dependent upon miR-155 for their proper expression through a mechanism involving repression of the transcription factor Ets1. Among the genes reduced in the absence of miR-155 was IL-23R, resulting in miR-155-/- Th17 cells being hypo-responsive to IL-23. Taken together, our study demonstrates a critical role for miR-155 in Th17 cells as they unleash autoimmune inflammation, and finds that this occurs through a signaling network involving miR-155, Ets1 and the clinically relevant IL-23-IL-23R pathway.
Project description:Th17 cells are key players in autoimmune diseases. However, the roles of non-coding RNAs in Th17 cells are largely unknown. Here, we show that deletion of the Dicer gene specifically in Th17 cells protects from experimental autoimmune encephalomyelitis (EAE). Th17 cells highly express the miR-183/96/182 cluster (miR-183C), in response to IL-6/STAT3 signaling. Moreover, miR-183C regulates pathogenic cytokine expression during Th17 development. Furthermore, transcription factor Foxo1 is one of functional targets of miR-183C in Th17 cells: Foxo1 negatively regulates the pathogenicity of Th17 cells and miR-183C represses Foxo1 expression. Collectively, our results demonstrate one of crucial roles for miR-183C cluster in regulation of Th17 cell function in autoimmune diseases.
Project description:The pro-inflammatory microRNA-155 (miR-155) is highly expressed in the serum and CNS lesions of patients with multiple sclerosis (MS). The whole-body deletion of miR-155 in mice confers resistance to a mouse model of MS, EAE, by reducing the encephalogenic potential of CNS-infiltrating Th17 T cells. However, cell intrinsic roles for miR-155 during EAE have not been formally determined. Here we utilize single-cell RNA sequencing and cell-specific conditional miR-155 knockouts to determine the importance of miR-155 expression in distinct immune cell populations. Time course single-cell sequencing revealed reductions in T cells, macrophages, and dendritic cells in whole-body miR-155 knockout mice compared with wild-type controls at day 21. Deletion of miR-155 in T cells, driven by CD4 cre, reduced disease severity similar to whole-body miR-155 knockouts. CD11c cre-driven deletion of miR-155 in dendritic cells also significantly reduced EAE disease score, with both T cell and dendritic cell-specific knockouts showing a reduction in Th17 T cell infiltration into the CNS. Although miR-155 is highly expressed in infiltrating macrophages during EAE, deletion of miR-155 using LysM cre did not affect disease severity. Taken together, these data show that while miR-155 is highly expressed in most infiltrating immune cells, miR-155 has distinct roles and requirements depending on the cell type. This provides insights into which functionally relevant cell types should be targeted by the next generation of miRNA therapeutics.
Project description:Genome-wide analysis was performed on microRNA 155+/+ and -/- Th17 cells to determine the differentially expressed transcripts that are regulated by miR-155. We found that Jarid2 was differentially expressed in absence of miR-155 and highlight the mechanism for the silencing of IL-22 by Jarid2 and PRC2 in miR-155-/- Th17 cells.
Project description:Dysregulated Th17 cell responses underlie multiple inflammatory and autoimmune diseases, including autoimmune uveitis and its animal model, EAU. However, clinical trials targeting IL-17A in uveitis were not successful. Here, we found that Th17 cells were regulated by their own signature cytokine, IL-17A. Loss of IL-17A in autopathogenic Th17 cells did not reduce their pathogenicity and instead elevated their expression of the Th17 cell cytokines GM-CSF and IL-17F. Mechanistic in vitro studies revealed a Th17 cell-intrinsic autocrine loop triggered by binding of IL-17A to its receptor, leading to activation of transcription factor NFκB and induction of IL 24, which repressed the Th17 cytokine program. In vivo, IL-24 treatment ameliorated Th17-induced EAU, whereas silencing of IL-24 in Th17 cells enhanced disease. This regulatory pathway also operated in human Th17 cells. Thus, IL-17A limits pathogenicity of Th17 cells by inducing IL-24. These findings may explain the disappointing therapeutic effect in targeting IL-17A in uveitis.
Project description:CD4+ Th17 T cells are a key helper population in the regulation of both protective immunity during infection and in self-tolerance. Through the secretion of IL-17, Th17 cells act in promotion of inflammation and thus a major therapeutic target for autoimmune disorders. Recent reports have brought to light that the IL-17 family cytokines, IL-17A, IL-17F and IL-17AF, can directly act on CD4+ T-cells, both in murine and human systems. Here we show that this action is preferentially targeted toward naïve, but not memory, CD4+ T-cells. Moreover, IL-17A, IL-17F and IL-17AF led to reduction in immune signaling genes, but an increase in interferon responsive genes across all treatments. In addition, IL-17A, IL-17F and IL-17AF treatment possessed differences in downstream transcriptional signaling, with IL-17AF heterodimer conferring both the greatest transcriptional change and suppressed phenotype. Detailed transcriptome analysis provides important functional insights into the genes and pathways that are modulated as a result of IL-17-mediated signaling.
Project description:Our results introduce interleukin (IL)-11 as a new cytokine that may play a role in the development of the autoimmune response in patients with relapsing remitting multiple sclerosis (RR MS). IL-11 was found to be the highest up-regulated cytokine in the serum and cerebrospinal fluid (CSF) from patients with clinically isolated syndrome (CIS) suggestive of MS. It was also increased in the serum and CSF of patients with clinically definitive RRMS and during the clinical relapses of the disease. CD4+ cells represent a predominant cell source of IL-11 in the peripheral circulation, and the percentage of IL-11+CD4+ cells is significantly increased in CIS patients in comparison to healthy controls (HCs). Furthermore, we have identified IL-11 as a new Th17-promoting cytokine. IL-11 induces a differentiation of naïve CD4+ T cells into Th17 cells, as well as Th17 memory cell expansion, characterized by secretion of IL-17A, IL-17F, IL-21 and IL-22. Since the Th17 cytokines IL-17F, IL-21 and TNF- induced differentiation of naïve cells in the IL-11-secreting CD4+ cells, we propose that cross-talk between IL-11+CD4+ and Th17-cells may play a role in the initiation and propagation of the autoimmune response in RRMS. PBMCs were separated from 15 CIS patients and 7 HCs, and the total RNA was extracted and used for gene array hybridization as described previously. To detect differential gene expression profiles between the CIS patients and HCs, a two class paired test of significance analysis was used.
Project description:Our results introduce interleukin (IL)-11 as a new cytokine that may play a role in the development of the autoimmune response in patients with relapsing remitting multiple sclerosis (RR MS). IL-11 was found to be the highest up-regulated cytokine in the serum and cerebrospinal fluid (CSF) from patients with clinically isolated syndrome (CIS) suggestive of MS. It was also increased in the serum and CSF of patients with clinically definitive RRMS and during the clinical relapses of the disease. CD4+ cells represent a predominant cell source of IL-11 in the peripheral circulation, and the percentage of IL-11+CD4+ cells is significantly increased in CIS patients in comparison to healthy controls (HCs). Furthermore, we have identified IL-11 as a new Th17-promoting cytokine. IL-11 induces a differentiation of naïve CD4+ T cells into Th17 cells, as well as Th17 memory cell expansion, characterized by secretion of IL-17A, IL-17F, IL-21 and IL-22. Since the Th17 cytokines IL-17F, IL-21 and TNF- induced differentiation of naïve cells in the IL-11-secreting CD4+ cells, we propose that cross-talk between IL-11+CD4+ and Th17-cells may play a role in the initiation and propagation of the autoimmune response in RRMS. PBMCs were separated from 15 CIS patients and 7 HCs, and the total RNA was extracted and used for gene array hybridization as described previously. To detect differential gene expression profiles between the CIS patients and HCs, a two class paired test of significance analysis was used. In order to capture complex gene expression changes in the PBMCs derived from 15 CIS patients in comparison to 7 HCs, we performed a comprehensive study using Affymetrix Human Gene array U133 (HG-U133) with 45,000 probe sets representing approximately 33,000 human genes. The arrays were hybridized for 16 h at 45oC in a GeneChip® Hybridization Oven 640 (Affymetrix), washed and stained with R-phycoerythrin streptavidin in a GeneChip® Fluidics Station 400 (Affymetrix). The arrays were scanned with a Hewlett Packard GeneArray Scanner. Affymetrix GeneChip® Microarray Suite 5.0 software was used for washing, scanning, and basic analysis. To detect differential gene expression profiles between the CIS patients and HCs, a two class paired test of significance analysis of microarrays was used. Differentially expressed genes were determined using a Welch two sample t-test. A p<0.05 was considered significant.
Project description:Multiple sclerosis is a chronic autoimmune disease driven by pathogenic Th17 cells. Here, we dissected the role of miR-22 in pathogenic Th17 cells by autoantigen-specific disease models. We first showed that miR-22 was upregulated in peripheral lymphoid organs and spinal cords of mice developed autoimmune encephalomyelitis. Although miR-22 was upregulated in multiple helper T cell subsets, it was dispensable for T helper cell differentiation in vitro. While miR-22-/- mice exhibited milder symptoms of disease in an active EAE model, adoptive transfer of miR-22-/- 2D2 Th17 cells into naive recipient mice promoted higher disease incidence and severity compared to mice transferred with control 2D2 Th17 cells. Global transcriptional analysis of miR-22-deficient pathogenic Th17 cells revealed upregulated genes in phosphatase and tensin homologue (PTEN)-mediated pathways, and Pten was further identified as one of its potential targets. Therefore, we identified that Th17 cell intrinsic-miR-22 could protect mice from autoimmunity by targeting PTEN-regulated pathways.
Project description:Multiple sclerosis (MS) is an autoimmune demyelinating disease affecting the central nervous system (CNS). T helper (Th) 17 cells are involved in the pathogenesis of MS and its animal model of experimental autoimmune encephalomyelitis (EAE) by infiltrating the CNS and producing effector molecules that engage resident glial cells. Among these glial cells, astrocytes have a central role in coordinating inflammatory processes by responding to cytokines and chemokines released by Th17 cells. In this study, we examined the impact of pathogenic Th17 cells on astrocytes in vitro and in vivo. We identified that Th17 cells reprogram astrocytes by driving transcriptomic changes partly through a Janus Kinase (JAK)1-dependent mechanism, which included increased chemokines, interferon-inducible genes, and cytokine receptors. In vivo, we observed a region-specific heterogeneity in the expression of cell surface cytokine receptors on astrocytes, including those for TGFβ, IL-10, IL-1, IL-17, IFN-γ, and TNF-α. Additionally, these receptors were dynamically regulated during EAE induced by adoptive transfer of myelin-reactive Th17 cells. This study overall provides evidence of Th17 cell reprogramming of astrocytes, which may drive changes in the astrocytic responsiveness to cytokines during autoimmune neuroinflammation.