Project description:Human IL-10– and IL-10+ TH17 clones maintained their pro- or anti-inflammatory characteristics after long-term culture. There were similarities between human IL-10– vs. IL-10+ TH17 clones and mouse pathogenic vs. non-pathogenic TH17 cells.
Project description:T helper cells integrate signals from their microenvironment to acquire distinct specialization programs for efficient clearance of diverse pathogens or for immunotolerance. Ionic signals have recently been demonstrated to affect T cell polarization and function. Sodium chloride (NaCl) was proposed to accumulate in peripheral tissues upon dietary intake and to promote autoimmunity via the Th17 cell axis. Here we demonstrate that high NaCl conditions induced a stable, pathogen-specific, anti-inflammatory Th17 cell fate in human T cells in vitro. The p38/MAPK pathway, involving NFAT5 and SGK1, regulated FoxP3 and interleukin (IL)-17-expression in high-NaCl conditions. The NaCl-induced acquisition of an anti-inflammatory Th17 cell fate was confirmed in vivo in an experimental autoimmune encephalomyelitis (EAE) mouse model, which demonstrated strongly reduced disease symptoms upon transfer of T cells polarized in high NaCl conditions. However, NaCl was coopted to promote murine and human Th17 cell pathogenicity, if T cell stimulation occurred in a pro-inflammatory and TGF--low cytokine microenvironment. Taken together, our findings reveal a context-dependent, dichotomous role for NaCl in shaping Th17 cell pathogenicity. NaCl might therefore prove beneficial for the treatment of chronic inflammatory diseases in combination with cytokine-blocking drugs.
Project description:Human peripheral blood IFN-γ+IL-17+ (TH1/17) and IFN-γ–IL-17+ (TH17) CD4+ T cells display distinct transcriptional profiles in high-throughput transcription analyses. Compared to TH17 cells, TH1/17 cells have similar gene signatures to mouse pathogenic TH17 cells.
Project description:Th17 cells are a heterogeneous population that is critical for tissue homeostasis and inflammation during clearance of infections and autoimmunity. Despite substantial efforts distinguishing homeostatic and inflammatory roles of Th17 cells, the mechanism underlying the divergent functions of inflammatory Th17 cells is poorly understood. In this study, we show that the inflammatory Th17 engaged in autoimmune colitis and those involved in infection-induced colitis are two distinguishable populations illustrated by their distinct responses to a pharmacological molecule, clofazimine (CLF). Distinct from existing Th17 inhibitors, CLF selectively inhibits pro-autoimmune Th17 cells while preserving the functional state of infection-elicited Th17 cells through restricting Aldh1l2expression. Using bulk RNA sequencing, we explored transcriptional response to CLF on in vitro differentiated inflammatory and homeostatic Th17 cells. Notably, we identified a unique suppression in the transcription of signature inflammatory genes in Th17 cells with a marginal effect on those elicited by infection.
Project description:Th17 cells are a heterogeneous population that is critical for tissue homeostasis and inflammation during clearance of infections and autoimmunity. Despite substantial efforts distinguishing homeostatic and inflammatory roles of Th17 cells, the mechanism underlying the divergent functions of inflammatory Th17 cells is poorly understood. In this study, we show that the inflammatory Th17 engaged in autoimmune colitis and those involved in infection-induced colitis are two distinguishable populations illustrated by their distinct responses to a pharmacological molecule, clofazimine (CLF). Distinct from existing Th17 inhibitors, CLF selectively inhibits pro-autoimmune Th17 cells while preserving the functional state of infection-elicited Th17 cells through restricting Aldh1l2expression. Using single-cell RNA sequencing, we explored inflammatory Th17 transcriptional response to CLF from the colonic tissue of mice during autoimmune colitis and Citrobacter rodentiuminfection using Rorc gfp/+ reportor mice. Notably, we identified a unique suppression in the transcription of signature inflammatory genes in Th17 cells from autoimmune colitis with a marginal effect on those elicited by infection. Additionally, we illustrate with these data that the transcriptionally programming of pro-autoimmune Th17 cells are, indeed, unique compared to infection-elicited Th17 cells. Finally, we analyzed the impact of CLF on human inflammatory Th17 cells from the inflammed colon of a patient with IBD.
Project description:Th17 cells are extensively studied because of their known pathogenic role in many inflammatory diseases, but are also important to support the integrity of the intestinal barrier in a non-inflammatory manner. Since therapeutic targeting of Th17 cell mediated pathologies carries the risk of inadvertently affecting protective Th17 cells, we set out to define the major distinctions between homeostatic tissue-resident Th17 cells and Th17 cells engaged in inflammatory reactions, focusing on the gut. We show here that homeostatic Th17 cells exhibit little plasticity towards expression of inflammatory cytokines, are characterised by a metabolism typical for quiescent or memory T cells, and do not participate in inflammatory processes. Infection-induced Th17 cells, on the other hand, show extensive plasticity towards pro-inflammatory cytokines, disseminate widely into the periphery and engage aerobic glycolysis in addition to oxidative phosphorylation typical for inflammatory effector 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.