Project description:Purpose: RNA-sequencing analysis of Th17 signature genes. The goals of this study are to compared the gene expression between wild type (WT) and lncRNA-GM-/- Th17 cells by RNA-seq analysise.
Project description:T-helper 17 (Th17) cells play a dual role in immunological responses, serving as essential components in tissue homeostasis and host defense against microbial pathogens, while also contributing to proinflammatory conditions and autoimmunity. While Transforming Growth Factor-beta 1 (TGFβ1) is pivotal for the differentiation of non-pathogenic Th17 cells, the role of TGFβ3 and Activin in steering Th17 cells toward a pathogenic phenotype has been acknowledged. However, the molecular mechanisms governing this dichotomy remain elusive. In this study, we demonstrate that the transcription factor Foxo1 is upregulated in a TGFβ1 dose-dependent manner, serving as a critical regulator that specifically modulates the fate of pathogenic Th17 cells. Analyses in both uveitis patients and an Experimental Autoimmune Uveitis (EAU) mouse model reveal a strong correlation between disease severity and diminished Foxo1 expression levels. Ectopic expression of Foxo1 selectively attenuates IL-17A production under pathogenic Th17-inducing conditions. Moreover, enhanced Foxo1 expression, triggered by TGFβ1 signaling, is implicated in fatty acid metabolism pathways that favor non-pathogenic Th17 differentiation. Our drug screening identifies several FDA-approved compounds capable of upregulating Foxo1. Collectively, our findings offer compelling evidence that Foxo1 serves as a molecular switch to specifically control pathogenic versus non-pathogenic Th17 differentiation in a TGFβ1-dependent manner. These insights suggest that targeting Foxo1 could be a promising therapeutic strategy for autoimmune diseases, offering efficacy without compromising immune homeostasis.
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:STAT5 plays a critical role in mediating cellular responses following cytokine stimulation. The activated STAT5 proteins can form dimers and tetramers with distinct biological functions. The role of STAT5 tetramerization in autoimmune-mediated neuroinflammation has not been investigated. Using the STAT5 tetramer-deficient Stat5a-Stat5b N-domain double knock-in (DKI) mouse strain, we report here that STAT5 tetramers promote the pathogenesis of experimental autoimmune encephalomyelitis (EAE). The mild EAE phenotype observed in DKI mice correlates with the impaired extravasation of pathogenic Th17 cells and interactions between Th17 cells and monocyte-derived cells (MDCs) in the meninges. We further demonstrated that STAT5 tetramerization regulates the GM-CSF-dependent production of CCL17 by MDCs. Importantly, DKI Th17 cells expanded with CCL17 exhibit more severe EAE. Mechanistically, the effect of CCL17 is dependent on the activity of the integrin VLA-4. Thus, our study uncovered a novel GM-CSF-STAT5 tetramer-CCL17 pathway that promotes autoimmune neuroinflammation via the regulation of Th17 cell migration.
Project description:While intestinal Th17 cells are critical for maintaining tissue homeostasis, recent studies in both humans and mice have implicated their roles in the development of extra-intestinal autoimmune diseases such as multiple sclerosis. However, the mechanisms by which tissue Th17 cells mediate these dichotomous functions remain unknown. Here, we characterized the heterogeneity, plasticity, and migratory phenotypes of tissue Th17 cells in vivo by combining fate mapping with single-cell RNA sequencing to profile the transcriptomes and TCR clonotypes of over 84,000 Th17 cells at homeostasis and during CNS autoimmune inflammation. Inter- and intra-organ single-cell analyses revealed a homeostatic, stem-like TCF1+ IL-17+ SLAMF6+ population that traffics to the intestine where it is maintained by the microbiota, providing a ready-reservoir for the IL-23-driven generation of encephalitogenic GM-CSF+ IFNγ+ CXCR6+ T cells. Our study defines a direct relationship in vivo between IL-17+ non-pathogenic and GM-CSF+ and IFNγ+ pathogenic Th17 populations and provides, for the first time, a mechanism by which homeostatic intestinal Th17 cells direct extra-intestinal autoimmune disease.
Project description:The current study tracked ongoing and past GM-CSF expression in various immune cells from multiple organs, both under steady-state conditions and during autoimmune inflammation of the central nervous system (CNS). RNA sequencing (RNA-Seq) was used to identify differences between naïve and effector memory CD4⁺ T cells with (YFP+) or without (YFP-) a history of GM-CSF expression.
Project description:Interleukin 17 (IL-17) producing T helper 17 (Th17) cells are critical drivers of pathogenesis in a variety of autoimmune and inflammatory diseases. Strategies to mitigate excessive Th17 response thus remain an attractive target for immunotherapies. Here we report that Cancerous Inhibitor of Protein Phosphatase 2A (CIP2A) regulates IL-17 production by Th17 cells in human and mouse. Using CIP2A knock-out (KO) mice and siRNA-mediated CIP2A silencing in human primary CD4+ T cells, we demonstrated that CIP2A silencing results in a significant increase in IL-17 production. Interestingly, CIP2A deficient Th17 cells were characterized by increased strength and duration of STAT3 (Y705) phosphorylation. Genome-wide gene expression profile as well as the p-STAT3 (Y705) interactome of CIP2A deficient Th17 cells identified that CIP2A regulates the strength of the interaction between Acylglycerol kinase (AGK) and STAT3, and thereby, modulates STAT3 phosphorylation as well as expression of IL-17 in Th17 cells. Our results uncover the physiological function of CIP2A in Th17 cells and provides new opportunities for therapeutic intervention in Th17 cell mediated diseases.
Project description:Interleukin 9 (IL-9) producing helper T (Th9) cells play a crucial role in allergic inflammation, autoimmunity, immunity to extracellular pathogens and anti-tumor immune response. In addition to Th9, Th2, Th17 and Foxp3+ Treg cells produce IL-9. Transcription factor that is critical for IL-9 induction in Th2, Th9 and Th17 cells has not been identified. Here we show that Foxo1, a forkhead family transcription factor, requires for IL-9 induction in Th9 and Th17 cells. We further show that inhibition of AKT enhances IL-9 induction in Th9 cells while it reciprocally regulates IL-9 and IL-17 in Th17 cells via Foxo1. Mechanistically, Foxo1 binds and transactivates IL-9 and IRF4 promoters in Th9, Th17 and iTregs. Furthermore, loss of Foxo1 attenuates IL-9 in mouse and human Th9 and Th17 cells, and ameliorates allergic inflammation in asthma. Our findings thus identify that Foxo1 is essential for IL-9 induction in Th9 and Th17 cells.