Project description:IL-23 signaling plays a key role in the pathogenesis of chronic inflammatory and infectious diseases, yet the cellular targets and signaling pathways affected by this cytokine remain poorly understood. We show that IL-23 receptors are expressed on the large majority of human MAIT, but not of conventional T cells, suggesting that these innate-like T cells are critical mediators of IL-23 functions. In this study, we investigated the effects of IL-23 on human MAIT cell transcriptional and chromatin accessibility profiles, using RNA- and CITE-seq and ATAC-seq, respectively. Protein and transcriptional profiling at the population and single cell level demonstrates that stimulation with IL-23 or the structurally related cytokine IL-12 drives distinct functional profiles, revealing a high level of plasticity of MAIT cells. IL-23, in particular, affects key molecules and pathways related to autoimmunity and cytotoxic functions. Integrated analysis of transcriptomic and chromatin accessibility shows that AP-1 transcription factors constitute a key regulatory node of the IL-23 pathway in MAIT cells.
Project description:IL-23 signaling plays a key role in the pathogenesis of chronic inflammatory and infectious diseases, yet the cellular targets and signaling pathways affected by this cytokine remain poorly understood. We show that IL-23 receptors are expressed on the large majority of human MAIT, but not of conventional T cells, suggesting that these innate-like T cells are critical mediators of IL-23 functions. In this study, we investigated the effects of IL-23 on human MAIT cell transcriptional and chromatin accessibility profiles, using RNA- and CITE-seq and ATAC-seq, respectively. Protein and transcriptional profiling at the population and single cell level demonstrates that stimulation with IL-23 or the structurally related cytokine IL-12 drives distinct functional profiles, revealing a high level of plasticity of MAIT cells. IL-23, in particular, affects key molecules and pathways related to autoimmunity and cytotoxic functions. Integrated analysis of transcriptomic and chromatin accessibility shows that AP-1 transcription factors constitute a key regulatory node of the IL-23 pathway in MAIT cells.
Project description:IL-23 signaling plays a key role in the pathogenesis of chronic inflammatory and infectious diseases, yet the cellular targets and signaling pathways affected by this cytokine remain poorly understood. We show that IL-23 receptors are expressed on the large majority of human MAIT, but not of conventional T cells, suggesting that these innate-like T cells are critical mediators of IL-23 functions. In this study, we investigated the effects of IL-23 on human MAIT cell transcriptional and chromatin accessibility profiles, using RNA- and CITE-seq and ATAC-seq, respectively. Protein and transcriptional profiling at the population and single cell level demonstrates that stimulation with IL-23 or the structurally related cytokine IL-12 drives distinct functional profiles, revealing a high level of plasticity of MAIT cells. IL-23, in particular, affects key molecules and pathways related to autoimmunity and cytotoxic functions. Integrated analysis of transcriptomic and chromatin accessibility shows that AP-1 transcription factors constitute a key regulatory node of the IL-23 pathway in MAIT cells.
Project description:Interleukin 23 (IL-23) triggers pathogenic features in pro-inflammatory, IL-17-secreting T cells (Th17 and Tγδ17) that play a key role in the development of inflammatory diseases. However, the IL-23 signaling cascade remains largely undefined. Here we used quantitative phosphoproteomics to characterize IL-23 signaling in primary murine Th17 cells. We quantified 6,888 phosphorylation sites in Th17 cells, and found 168 phosphorylations regulated upom IL-23 stimulation. IL-23 increased the phosphorylation of the myosin regulatory light chain (RLC), an actomyosin contractibility marker, in Th17 and Tγδ cells. IL-23-induced RLC phosphorylation required JAK2 and ROCK catalytic activity, and the study of the IL-23/ROCK axis revealed an unexpected role of IL-23 in the migration of Tγδ17 and Th17 cells. Moreover, pharmacological inhibition of ROCK reduced Tγδ17 recruitment to inflamed skin upon challenge with inflammatory agent Imiquimod. This work: i) provides new insights into phosphorylation networks that control Th17 cells, ii) widely expands the current knowledge on IL-23 signaling, and iii) contributes to the increasing list of immune cells subsets characterized by global phosphoproteomic approaches.
Project description:Interleukin-23 (IL-23) and IL-17 are cytokines currently being targeted in clinical trials. Although inhibition of these cytokines is effective for treating psoriasis, IL-12/23 inhibition attenuates Crohn's disease, while IL-17A or IL-17RA inhibition exacerbates disease. This dichotomy between IL-23 and IL-17 was effectively modeled in the mdr1a- /- mouse model of colitis. IL-23 inhibition attenuated disease by decreasing colonic inflammation while enhancing Treg accumulation. Exacerbation of colitis by IL-17A or IL-17RA inhibition was associated with severe weakening of the intestinal epithelial barrier, culminating in increased colonic inflammation and accelerated mortality. These data show that IL-17A acts on intestinal epithelium to promote barrier function and provides insight into mechanisms underlying exacerbation of Crohn's disease when IL-17A or IL-17RA is inhibited.
Project description:We performed RNA-Seq analysis and compared three groups 1) WT+IL-23 v. WT+GFP (control), 2) Mdl1-/-+IL-23 v. WT+GFP (control), and 3) WT+IL-23 v. Mdl1-/-+IL-23. Sets of differentially expressed genes (DEG) were defined on the basis of standard thresholds i.e. a |log2FC|≥2 combined with an adjusted p-value≤0.01 against the control group. Differential expression analysis revealed 1171 (619 up-regulated and 552 down-regulated) DEGs in WT+IL-23 v. WT+GFP, 414 (303 up-regulated and 111 down-regulated) DEGs in Mdl1-/-+IL-23 v. WT+GFP, and 260 (122 up-regulated and 138 down-regulated) DEGs in WT+IL-23 v. Mdl1-/-+IL-23
Project description:MAIT cells (MAITs) represent an abundant T lymphocyte subset with unique specificity for microbial metabolites presented by the MHC-1b molecule, MR1. MAIT conservation along evolution indicates important, non-redundant functions, but their low frequency in mice has hampered their detailed characterization. Here, we performed a transcriptomic analysis of murine MAITs in comparison with NKT subsets and with mainstream T cells in spleen and peripheral organs of B6-MAIT/CAST mice expressing a Rorc-GFP transgene. MAIT and NKT cells have been FACS-sorted after tetramer staining (MR1:5-OP-RU Tet+ for MAIT, CD1d:PBS57Tet+ for NKT), and 1/17 subsetting based on the expression of Rorc.
Project description:At mucosal surfaces, epithelial cells provide a structural barrier and an immune defense system. However, dysregulated epithelial responses can contribute to disease states. Here, we demonstrate that epithelial intrinsic production of IL-23 triggers an inflammatory loop in the prevalent oral disease, periodontitis. Epithelial IL-23 expression localized to areas proximal to the disease-associated microbiome, is evident both in experimental models and in patients with common and genetic forms of disease. Mechanistically, flagellated microbial species of the periodontitis microbiome, trigger epithelial IL-23 induction in a TLR5-dependent manner. Intriguingly, unlike other Th17-driven diseases, here non-hematopoietic cell-derived IL-23 serves as an initiator of pathogenic inflammation. Beyond periodontitis, analysis of publicly available datasets reveals expression of epithelial IL-23 in settings of infection, malignancy, and autoimmunity, suggesting a broader role for epithelial-intrinsic IL-23 in human disease. Collectively, this work highlights an unappreciated role for the barrier epithelium in the induction of IL-23-mediated inflammation.