Elucidating the molecular mechanisms underlying ligand-dependent REV-ERB activity in Th17 cells

阐明 Th17 细胞中配体依赖性 REV-ERB 活性的分子机制

• 批准号: 10319925
• 负责人: Sarah Mosure
• 金额: $ 0.91万
• 依托单位: SCRIPPS FLORIDA
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-01-01 至 2022-04-01
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10319925
• 关键词: Address; Affect; Binding; Biology; Cell Nucleus; Cells; Chronic; Clinical; Colitis; Conflict (Psychology); Coupled; Crohn' s disease; Data; Disease Progression; Disease susceptibility; Ensure; Enzymes; Florida; Flow Cytometry; Gastrointestinal tract structure; Gene Expression; Genes; Genetic Polymorphism; Genetic Predisposition to Disease; Genetic Transcription; Goals; Heme; Histology; Immune response; Immunology; In Vitro; Incidence; Individual; Infiltration; Inflammatory; Inflammatory Bowel Diseases; Interleukin-17; Intrinsic factor; Ligand Binding; Ligands; Mentorship; Molecular; Molecular Conformation; Molecular Immunology; NMR Spectroscopy; Nuclear Receptors; Pathogenesis; Pathogenicity; Pathway interactions; Patients; Phenotype; Porphyrins; Process; Production; Proteins; Publishing; Receptor Cell; Regulation; Repression; Research; Resource Development; Response Elements; Role; Severity of illness; Signal Pathway; Signal Transduction; Signaling Molecule; Source; Structure; Susceptibility Gene; Testing; Therapeutic; Time; Tissues; Training; Ulcerative Colitis; Work; X-Ray Crystallography; base; biophysical techniques; chemokine; chronic inflammatory disease; cytokine; design; effective therapy; experimental study; extracellular; gastrointestinal; gene repression; genetic corepressor; genome wide association study; gut microbiota; heme biosynthesis; in vivo; in vivo Model; insight; knock-down; mouse model; neutralizing antibody; novel; prevent; protective effect; rev Genes; structural biology; success; targeted treatment; transcription factor

Project Summary/Abstract Inflammatory bowel diseases (IBD), including Crohn’s disease and ulcerative colitis are characterized by an inappropriate immune response to commensal gut flora that causes chronic damage to the gastrointestinal (GI) tract. Genome-wide association studies showing genes associated with T helper 17 (Th17) immune responses are strongly implicated in IBD susceptibility together with clinical evidence of Th17 cells in GI tissues of IBD patients have identified a central role for Th17 cells in IBD pathogenesis. Although Th17 cells are characterized by the production of IL-17A, they also produce many other molecules each with critical roles in regulating the immune response. This could explain why IL-17A-neutralizing antibodies have had little success in treating IBD, while targeting factors within Th17 cells that broadly regulate their expression of effector molecules may be a more effective strategy. To this end, we recently demonstrated that the closely related REV-ERB (REV-ERBa and REV-ERBb) nuclear receptors (NRs) are cell-intrinsic repressors of Th17 cell pathogenicity. Transcriptional repression of signature Th17 cell genes by the REV-ERBs is essential for limiting disease severity in mouse models of chronic inflammatory disease and treatment with synthetic REV-ERB ligands developed at Scripps Florida enhanced the protective effect. The porphyrin, heme, is the endogenous ligand for the REV-ERBs and my preliminary data indicate that heme is important for REV-ERB activity in Th17 cells. Since NR ligands evolved to transmit extracellular or intracellular signals into changes in gene expression, understanding the source and effects of heme-dependent REV-ERB activity in Th17 cells may reveal signaling pathways underlying IBD pathogenesis that could be exploited for therapeutic benefit. At the same time, although the basis for ligand- dependent NR activity is in their regulation of NR structure, contradictory evidence between published cell-based and structural studies has prevented understanding of the molecular basis for heme-dependent REV-ERB activity. My preliminary data reveal a potential solution to this conflict. My overarching hypothesis is that heme produced intracellularly in Th17 cells enhances REV-ERB repression of a pathogenic Th17 cell phenotype by stabilizing the REV-ERBs’ interaction with a transcriptionally repressive coregulator (corepressor) protein. I will test this hypothesis through two central aims: 1) I will identify the role of heme as a REV-ERB-dependent signaling molecule in Th17 cells and 2) I will define the heme-dependent structural changes that influence REV-ERB activity. I expect the results of these aims to characterize an underexplored signaling pathway in Th17 cells that could be targeted to treat IBD. In the process, I will receive comprehensive training in immunology and structural biology approaches from a unique, interdisciplinary mentorship team. Together with the extensive professional development resources at Scripps Florida, this team will ensure that I progress toward achieving my long-term goal of directing a research lab studying the molecular basis of chronic inflammatory diseases such as IBD.

项目总结/摘要 炎症性肠病（IBD），包括克罗恩病和溃疡性结肠炎，其特征在于： 对胃肠道植物群的不适当免疫反应，导致胃肠道（GI）慢性损伤 道。全基因组关联研究显示与辅助性T细胞17（Th 17）免疫应答相关的基因 与IBD易感性以及IBD GI组织中Th 17细胞的临床证据密切相关 患者已经确定了Th 17细胞在IBD发病机制中的中心作用。虽然Th 17细胞的特征在于 通过产生IL-17 A，它们还产生许多其他分子，每一种分子在调节 免疫反应这可以解释为什么IL-17 A中和抗体在治疗IBD方面几乎没有成功， 而Th 17细胞内广泛调节其效应分子表达的靶向因子可能是一种靶向因子， 更有效的战略。为此，我们最近证明，密切相关的REV-ERB（REV-ERBa 和REV-ERBb）核受体（NR）是Th 17细胞致病性的细胞内在阻遏物。转录 REV-ERB对标志性Th 17细胞基因的抑制对于限制小鼠疾病严重程度是必需的 慢性炎症性疾病模型和用Scripps开发的合成REV-ERB配体治疗 佛罗里达增强了保护作用。卟啉，血红素，是REV-ERB的内源性配体， 我的初步数据表明血红素对Th 17细胞中REV-ERB活性很重要。由于NR配体的发展， 将细胞外或细胞内信号转化为基因表达的变化，了解其来源， Th 17细胞中血红素依赖性REV-ERB活性的作用可能揭示IBD的信号通路 发病机制，可以利用治疗效益。与此同时，虽然配体的基础- 依赖NR活性是在其NR结构的调节，矛盾的证据之间公布的细胞为基础的 结构研究阻碍了对血红素依赖性REV-ERB的分子基础的理解 活动我的初步数据揭示了这场冲突的潜在解决方案。我的假设是血红素 在Th 17细胞中胞内产生增强致病性Th 17细胞的REV-ERB抑制 通过稳定REV-ERB与转录抑制辅调节因子的相互作用来调节表型 （辅阻遏物）蛋白。我将通过两个中心目标来检验这一假设：1）我将确定血红素的作用， REV-ERB依赖性信号分子在Th 17细胞和2）我将定义血红素依赖性结构 影响REV-ERB活性的变化。我希望这些目标的结果能够描述一个探索不足的 Th 17细胞中的信号通路，可以靶向治疗IBD。在此过程中，我将全面了解 来自独特的跨学科导师团队的免疫学和结构生物学方法培训。 与斯克里普斯佛罗里达广泛的专业发展资源一起，这个团队将确保我 我的长期目标是指导一个研究实验室，研究慢性病毒性肝炎的分子基础。 炎症性疾病，如IBD。