Project description:CD4 T cells are an essential component of antiviral adaptive immune cell responses. Central to the functional capabilities of CD4 T Cells is their ability to differentiate into distinct subsets. Subset differentiation and maintenance is dependent on the coordinated and sequential activation of certain master regulator transcription factors. While antiviral responses are predominantly Th1, prior studies have shown that both T-bet and Eomes, two critical regulators of Th1 responses are dispensable for CD4 T cell mediated protection. CD4 T Cells lacking both T-bet and Eomes produce strong and highly protective Th17 response characterized by high expression of the transcription factor RORγt. Here we determine the impact of RORγt regulation in CD4 T Cells primed under Th17 conditions and also deficient in T-bet and Eomes. Our studies reveal RORγt regulates several hundred genes that in Th17 CD4 T Cells, thus providing a potential molecular framework for targeting protective anti-viral immunity.
Project description:RORgt is known to instruct the differentiation of Th17 cells that mediate the pathogenesis of autoimmune diseases. However, it remains unknown whether RORgt plays a distinct role in the differentiation and effector function of Th17 cells. Here we show that mutation of RORgt lysine 256, a ubiquitination site, to arginine (K256R) separates the RORgt role in these two functions. Preventing ubiquitination at K256 via arginine substitution does not affect RORgt-dependent thymocyte development and Th17 differentiation in vitro and in vivo, however, greatly impaired the pathogenesis of Th17 cell-mediated experimental autoimmune encephalomyelitis (EAE). Mechanistically, K256R mutation impairs RORgt to bind to and activate Runx1 expression critical for Th17-mediated EAE. Thus, RORgt regulates the effector function of Th17 cells in addition to Th17 differentiation. This work informs the development of RORgt-based therapies that specifically target the effector function of Th17 cells responsible for autoimmunity.
Project description:Th17 cells are a helper cell subset of pro-inflammatory T cells, which have diverse functions ranging from neutrophilic-inflammatory responses against pathogens to driving a number of autoimmune diseases. Accumulating evidence indicates that specific cellular lipid metabolic pathways that include fatty acid or cholesterol play an essential role in regulating the differentiation and function of Th17 cells. However, what molecular mechanisms link lipid metabolism and RORgt function during Th17-cell differentiation? By using a combination of a CRISPR- based screening system and a global lipidome analysis, we addressed this question in an effort to identify a specific lipid metabolite that is essential for RORgt-mediated Th17-cell differentiation. We found five lipid enzymes that elicit RORgt activity and constitute a core molecular signature of Th17 cells. Furthermore, although Th17 cells treated with TOFA, which is a ACC1 inhibitor, showed decreased mRNA expression of Th17 specific gene and chromatin accessibility at Th17 cell specific gene loci, we also found that extrinsic supplementation of LPE (1-18:1) restored the phenotype of ACC1-inhibited Th17 cells. Taken together, these series of results indicated that LPE (1-18:1) synthesized from the five lipid metabolic enzymes was required for RORgt to function appropriately in Th17-cell differentiation.
Project description:T helper 17 (Th17) cells produce interleukin-17 (IL-17) cytokines and drive inflammatory responses in autoimmune diseases such as multiple sclerosis and rheumatoid arthritis. The differentiation of Th17 cells is dependent on the retinoic acid receptor-related orphan nuclear receptor RORgt. Here we identify REV-ERBa (encoded by Nr1d1), a member of the nuclear hormone receptor family (NHR), as a transcriptional repressor that antagonizes RORgt function in Th17 cells. REV-ERBa binds to ROR response elements (RORE) in Th17 cells and inhibits the expression of RORgt-dependent genes such as Il17a and Il17f. Furthermore, elevated REV-ERBa expression or treatment with a synthetic REV-ERB agonist significantly delays the onset and impedes the progression of experimental autoimmune encephalomyelitis (EAE), a Th17 cell-mediated autoimmune disease. These results suggest that modulating REV-ERB activity may hold therapeutic potential for treatment of Th17 cell-mediated autoimmune diseases.
Project description:RORgt is known to instruct the differentiation of Th17 cells that mediate the pathogenesis of autoimmune diseases. However, it remains unknown whether RORgt plays a distinct role in the differentiation and effector function of Th17 cells. Here we show that mutation of RORgt lysine 256, a ubiquitination site, to arginine (K256R) separates the RORgt role in these two functions. Preventing ubiquitination at K256 via arginine substitution does not affect RORgt-dependent thymocyte development and Th17 differentiation in vitro and in vivo, however, greatly impaired the pathogenesis of Th17 cell-mediated experimental autoimmune encephalomyelitis (EAE). Mechanistically, K256R mutation impairs RORgt to bind to and activate Runx1 expression critical for Th17-mediated EAE. Thus, RORgt regulates the effector function of Th17 cells in addition to Th17 differentiation. This work informs the development of RORgt-based therapies that specifically target the effector function of Th17 cells responsible for autoimmunity.
Project description:Purpose: The goals of this study are to compare RNAs bound by DDX5 and RORgt in cultured T helper 17 cell in wildtype background. Methods: Th17 mRNA profiles of 48hrs in vitro cultured T helper 17 cells from wild-type mice were generated by deep sequencing, using Illumina HighSeq. The sequence reads that passed quality filters were analyzed at the transcript isoform level with two methods: BurrowsâWheeler Aligner (BWA) and TopHat followed by CuffDiff. qRTâPCR validation was performed using SYBR Green assays. Results: Among the 3444 RefSeq non-coding RNAs and 46449 NONCODE non-coding RNAs, 2533 were found to be expressed in Th17 cells (FPKM>1). 210 of them were enriched in DDX5 pull-down and 119 of them were enriched in RORgt pull-down. Conclusions: Our study suggest that a subset of 31 ncRNAs were co-enriched in DDX5 and RORgt pull-down. DDX5 or RORgt-associated-RNA profiles of 48hr in vitro cultured Th17 from wild type (WT) mice were generated by deep sequencing using Illumina HighSeq
Project description:The aim of this study was to analyze the global transcriptional profiles of small intestine (SI) Innate Lymphoid Cells (ILCs) expressing the NK cell marker NKp46. Based on differential expression of the RORgt transcription factor SI NKp46+ ILCs can be divided in NKp46+RORgt- and NKp46+RORgt+ cells. While NKp46+RORgt- cells produce IFN-g, like conventional Natural Killer (NK) cells, NKp46+RORgt+ cells secrete IL-22, like Lymphoid Tissue inducer (LTi) cells. We compared the global transcriptional profiles of both NKp46+RORgt- and NKp46+RORgt+ cells to conventional splenic NK cells and to SI NKp46-RORgt+ cells, which contain adult LTi cells. By following this approach, we showed that SI NKp46+RORγt- ILCs correspond to SI NK cells. We also identified a transcriptional program conserved in adult SI NKp46+RORγt+, NKp46-RORγt+ ILCs and fetal LTi. The various ILC cell populations analyzed in this study were isolated from C57BL/6 RORc(gt)+/GFP reporter mice. SI NKp46+RORγt- (NKp46+GFP-) cells, SI NKp46+RORγt+ cells (NKp46+GFPlow and NKp46+GFPhigh cells) and NKp46-RORγt+ ILCs, including adult LTi cells , were sorted by flow cytometry from CD3- lamina propria cells of small intestine (SI) of RORc(γt)+/GFP reporter mice . Splenic NKp46+RORγt- (NKp46+GFP-) cells were also sorted as the reference for conventional NK cells. Two replicates of each populations were produced and analyzed.