Project description:CD4+ T helper lymphocytes that express interleukin-17 (Th17 cells) have critical roles in mouse models of autoimmunity, and there is mounting evidence that they also influence inflammatory processes in humans. Genome-wide association studies in humans have linked genes involved in Th17 cell differentiation and function with susceptibility to Crohn’s disease, rheumatoid arthritis, and psoriasis1-3. Thus, the pathway towards differentiation of Th17 cells and, perhaps, of related innate lymphoid cells with similar effector functions4, 5, is an attractive target for therapeutic applications. Mouse and human Th17 cells are distinguished by expression of the retinoic acid receptor-related orphan nuclear receptor RORγt, which is required for induction of IL-17 transcription and for the manifestation of Th17-dependent autoimmune disease in mice6. By performing a chemical screen with an insect cell-based reporter system, we identified the cardiac glycoside digoxin as a specific inhibitor of RORγt transcriptional activity. Digoxin inhibited murine Th17 cell differentiation without affecting differentiation of other T cell lineages and was effective in delaying the onset and reducing the severity of autoimmune disease in mice. At high concentrations, digoxin is toxic for human cells, but non-toxic synthetic derivatives, 20,22-dihydrodigoxin-21,23-diol (Dig(dhd)) and digoxin-21-salicylidene (Dig(sal)), specifically inhibited induction of IL-17 in human CD4+ T cells. Using these small molecule compounds, we demonstrated that RORγt is imporant for the maintenance of IL-17 expression in mouse and human effector T cells. These data suggest that derivatives of digoxin can be used as chemical probes for development of RORγt-targeted therapeutic agents that attenuate inflammatory lymphocyte function and autoimmune disease. We performed gene expression profiling with total RNA samples isolated from DMSO- or digoxin-treated wildtype or RORγt-deficient cells cultured in Th17 conditions. Total RNA was extracted with TRIzol. RNA was labeled and hybridized to GeneChip Mouse Genome 430 2.0 arrays following the Affymetrix protocols. Data were analyzed in GeneSpring GX11.5.
Project description:CD4+ T helper lymphocytes that express interleukin-17 (Th17 cells) have critical roles in mouse models of autoimmunity, and there is mounting evidence that they also influence inflammatory processes in humans. Genome-wide association studies in humans have linked genes involved in Th17 cell differentiation and function with susceptibility to Crohn’s disease, rheumatoid arthritis, and psoriasis1-3. Thus, the pathway towards differentiation of Th17 cells and, perhaps, of related innate lymphoid cells with similar effector functions4, 5, is an attractive target for therapeutic applications. Mouse and human Th17 cells are distinguished by expression of the retinoic acid receptor-related orphan nuclear receptor RORγt, which is required for induction of IL-17 transcription and for the manifestation of Th17-dependent autoimmune disease in mice6. By performing a chemical screen with an insect cell-based reporter system, we identified the cardiac glycoside digoxin as a specific inhibitor of RORγt transcriptional activity. Digoxin inhibited murine Th17 cell differentiation without affecting differentiation of other T cell lineages and was effective in delaying the onset and reducing the severity of autoimmune disease in mice. At high concentrations, digoxin is toxic for human cells, but non-toxic synthetic derivatives, 20,22-dihydrodigoxin-21,23-diol (Dig(dhd)) and digoxin-21-salicylidene (Dig(sal)), specifically inhibited induction of IL-17 in human CD4+ T cells. Using these small molecule compounds, we demonstrated that RORγt is imporant for the maintenance of IL-17 expression in mouse and human effector T cells. These data suggest that derivatives of digoxin can be used as chemical probes for development of RORγt-targeted therapeutic agents that attenuate inflammatory lymphocyte function and autoimmune disease.
Project description:RORγt is a transcription factor required for T helper 17 (Th17) cell development. We identified three RORγt-specific inhibitors that suppress Th17 cell responses including Th17 cell-mediated autoimmune disease. We systemically characterized RORγt binding data in the presence and absence of drug with corresponding whole-transcriptome sequencing for wild-type and RORγt-deficient cells. RORγt is central in a densely interconnected regulatory network, acting both as a direct activator of genes important for Th17 cell differentiation and as a direct repressor of genes from other T-cell lineages. The three inhibitors identified here reversed both of these modes of action, but to varying extents and through distinct mechanisms. Whereas one inhibitor displaced RORγt from its target-loci, the two more potent inhibitors affected transcription predominantly without removing DNA-binding. Our work illustrates the power of a system-scale analysis of transcriptional regulation to characterize potential therapeutic compounds that inhibit pathogenic Th17 cells and suppress autoimmunity. DNA binding of RORγt in WT Th17 cells and under chemical perturbations of RORγt; Additional data is included for epitope-tagged exogenous RORγt in EL4 cells (a murine lymphoma cell line)
Project description:RORγt is a transcription factor required for T helper 17 (Th17) cell development. We identified three RORγt-specific inhibitors that suppress Th17 cell responses including Th17 cell-mediated autoimmune disease. We systemically characterized RORγt binding data in the presence and absence of drug with corresponding whole-transcriptome sequencing for wild-type and RORγt-deficient cells. RORγt is central in a densely interconnected regulatory network, acting both as a direct activator of genes important for Th17 cell differentiation and as a direct repressor of genes from other T-cell lineages. The three inhibitors identified here reversed both of these modes of action, but to varying extents and through distinct mechanisms. Whereas one inhibitor displaced RORγt from its target-loci, the two more potent inhibitors affected transcription predominantly without removing DNA-binding. Our work illustrates the power of a system-scale analysis of transcriptional regulation to characterize potential therapeutic compounds that inhibit pathogenic Th17 cells and suppress autoimmunity. Transcriptional profiling of Th17 cells under chemical perturbations of RORγt, DMSO, and knockout of RORγt. It includes repeats for all the data in GSE56018, plus one additional condition.
Project description:RORγt is a transcription factor required for T helper 17 (Th17) cell development. We identified three RORγt-specific inhibitors that suppress Th17 cell responses including Th17 cell-mediated autoimmune disease. We systemically characterized RORγt binding data in the presence and absence of drug with corresponding whole-transcriptome sequencing for wild-type and RORγt-deficient cells. RORγt is central in a densely interconnected regulatory network, acting both as a direct activator of genes important for Th17 cell differentiation and as a direct repressor of genes from other T-cell lineages. The three inhibitors identified here reversed both of these modes of action, but to varying extents and through distinct mechanisms. Whereas one inhibitor displaced RORγt from its target-loci, the two more potent inhibitors affected transcription predominantly without removing DNA-binding. Our work illustrates the power of a system-scale analysis of transcriptional regulation to characterize potential therapeutic compounds that inhibit pathogenic Th17 cells and suppress autoimmunity.
Project description:RORγt is a transcription factor required for T helper 17 (Th17) cell development. We identified three RORγt-specific inhibitors that suppress Th17 cell responses including Th17 cell-mediated autoimmune disease. We systemically characterized RORγt binding data in the presence and absence of drug with corresponding whole-transcriptome sequencing for wild-type and RORγt-deficient cells. RORγt is central in a densely interconnected regulatory network, acting both as a direct activator of genes important for Th17 cell differentiation and as a direct repressor of genes from other T-cell lineages. The three inhibitors identified here reversed both of these modes of action, but to varying extents and through distinct mechanisms. Whereas one inhibitor displaced RORγt from its target-loci, the two more potent inhibitors affected transcription predominantly without removing DNA-binding. Our work illustrates the power of a system-scale analysis of transcriptional regulation to characterize potential therapeutic compounds that inhibit pathogenic Th17 cells and suppress autoimmunity.
Project description:RORγt is a transcription factor required for T helper 17 (Th17) cell development. We identified three RORγt-specific inhibitors that suppress Th17 cell responses including Th17 cell-mediated autoimmune disease. We systemically characterized RORγt binding data in the presence and absence of drug with corresponding whole-transcriptome sequencing for wild-type and RORγt-deficient cells. RORγt is central in a densely interconnected regulatory network, acting both as a direct activator of genes important for Th17 cell differentiation and as a direct repressor of genes from other T-cell lineages. The three inhibitors identified here reversed both of these modes of action, but to varying extents and through distinct mechanisms. Whereas one inhibitor displaced RORγt from its target-loci, the two more potent inhibitors affected transcription predominantly without removing DNA-binding. Our work illustrates the power of a system-scale analysis of transcriptional regulation to characterize potential therapeutic compounds that inhibit pathogenic Th17 cells and suppress autoimmunity.
Project description:TH17 cells play a critical role in mucosal immunity and also in multiple autoimmune diseases. The differentiation of TH17 cells is dictated by a master transcription factor, RORγt; however, the mechanism by which RORγt controls target genes is poorly understood. Here we identify the Swi/Snf chromatin remodeling complex as an essential regulator of TH17 cell differentiation. Loss of the expression of SRG3/mBAF155, a core subunit of the Swi/Snf complex, results in a specific downregulation of RORγt target genes such as IL-17A, IL-17F and IL-23R. Importantly, the comparative transcriptional analysis reveals a high similarity between RORγt and the Swi/Snf complex in the control of TH17-related gene expression. Mechanistically, the Swi/Snf complex partners with RORγt and coordinates a variety of RORγt–mediated epigenetic modifications, including both permissive and repressive ones. These results provide a basis for the understanding of how a master transcription factor RORγt cooperates with the Swi/Snf complex to govern the Th17 cell differentiation.
Project description:Natural compounds ursolic acid (UA) and digoxin isolated from fruits and other plants display potent anti-cancer effects in preclinical studies. UA and digoxin have been at clinical trials for treatment of different cancers including prostate cancer, pancreatic cancer and breast cancer. However, they displayed limited benefit to patients. Currently, a poor understanding of their direct targets and mechanisms of action (MOA) severely hinders their further development. We previously identified nuclear receptor RORγ as a novel therapeutic target for castration-resistant prostate cancer (CRPC) and triple-negative breast cancer (TNBC) and demonstrated that tumor cell RORγ directly activates gene programs such as androgen receptor (AR) signaling and cholesterol metabolism. Previous studies also demonstrated that UA and digoxin are potential RORγt antagonists in modulating the functions of immune cells such as Th17 cells. Here we showed that UA displays a strong activity in inhibition of RORγ-dependent transactivation function in cancer cells, while digoxin exhibits no effect at clinically relevant concentrations. In prostate cancer cells, UA down-regulates RORγ-stimulated AR expression and AR signaling, whereas digoxin up-regulates AR signaling pathway. In TNBC cells, UA but not digoxin alters RORγ-controlled gene programs of cell proliferation, apoptosis and cholesterol-biosynthesis.Together, our study reveals for the first-time that UA, but not digoxin, acts as a natural antagonist of RORγ in the cancer cells. Our finding that RORγ is a direct target of UA in cancer cells will help select patients with tumors that likely respond to UA treatment.