Define the role of REV-ERB in colonic RORgt+ regulatory T cells

项目总结 调节性T细胞(Treg)在维持免疫系统平衡和预防 自身免疫性疾病。Treg功能缺陷会导致自身免疫性疾病，而肿瘤内Treg可以阻断 有效的抗肿瘤免疫反应。树突状细胞可以在适应其组织方面进行进一步的特化 微环境。最近的研究表明，一种独特的RORgT(维甲酸相关孤儿受体)伽马 可在结肠固有层诱导表达Treg细胞群。这些RORgt+Tregs扮演一个 在抑制结肠炎中起重要作用。在Treg细胞中，REV-ERBA在RORgt+中高表达 结肠树，但不在RORGT-结肠树或脾树中。REV-ERB基因Treg特异性缺失的小鼠 更易患TNBS诱导的结肠炎，RORgT+Treg细胞减少，Th1/Th17细胞增加- 介导结肠内的炎症。RNA测序实验表明，一组基因的表达 与Treg功能相关的CTLA-4、IL-10和c-Maf在REV-ERB缺陷结肠树中降低 与WT控件相比。郑博士的实验室研究REV-ERB对Tregs的基因调控机制 使用Foxp3、REV-Erba和RORgt抗体与WT RORgt+iTregs进行切割和运行分析，以映射 它们的结合高峰是全基因组的。结果表明，这3种化合物的结合峰有明显的重叠 转录因子，提示Treg中Foxp3、Rev-ERB和RORgt之间的基因调控协调 细胞。拟议研究的总体目标是确定REV-ERB在Treg功能中的作用。这一目标将 通过解剖RORgT+Treg细胞中REV-ERB功能的分子机制来完成(目标1)， 以及鉴定REV-ERB在IBD小鼠模型Treg中的作用(目标2)。建议的结果： 研究有望揭示REV-ERB在RORgt+Tregs中的功能和机制作用。这样的结果是 期望进一步促进我们对RORgt+Treg的身份和功能是如何建立的理解 并得到了维护。此外，这项研究将提供关键的见解，如转录抑制因子，如REV- ERB在Treg细胞中起关键调节作用，调节转录激活子的功能。最后，结果 这项研究为开发针对REV-ERB的IBD治疗药物提供了证据 治疗。

PROJECT SUMMARY Regulatory T cells (Treg) play a crucial role in keeping the immune system in balance and preventing autoimmune disease. Defective Treg function leads to autoimmune diseases, while intra-tumor Tregs can block effective anti-tumor immune responses. Tregs can undergo further specialization in adaptation to their tissue microenvironment. Recent studies showed that a unique RORgt (retinoic acid–related orphan receptor gamma t) expressing Treg cell population could be induced in the colon lamina propria. These RORgt+ Tregs play an important role in the suppression of colon inflammation. In Treg cells, REV-ERBa is highly expressed in RORgt+ colonic Tregs, but not in RORgt- colonic Tregs or spleen Tregs. Mice with Treg-specific deletion of REV-ERB were more susceptible to TNBS-induced colitis with decreased RORgt+ Treg cells and increased Th1/Th17 cell- mediated inflammation in the colon. RNA-sequencing experiment showed that the expression of a set of genes related to Treg function, including CTLA-4, IL-10, and c-Maf, were reduced in REV-ERB deficient colonic Tregs compared to WT controls. To study the mechanism of gene regulation by REV-ERB in Tregs, Dr. Zheng’s lab performed Cut & Run assays with WT RORgt+ iTregs using Foxp3, REV-ERBa, and RORgt antibodies to map their binding peaks genome-wide. The results showed a significant overlap of the binding peaks of these 3 transcription factors, suggesting coordination in gene regulation among Foxp3, REV-ERB, and RORgt in Treg cells. The overall objective of the proposed study is to define the role of REV-ERB in Treg function. This goal will be accomplished by dissecting the molecular mechanism of REV-ERB function in RORgt+ Treg cells (Aim 1), and characterizing the role of REV-ERB in Treg in mouse models of IBD (Aim 2). The outcomes of the proposed study are expected to reveal the functional and mechanistic role of REV-ERB in RORgt+ Tregs. Such results are expected to further advance our understanding of how the identity and function of RORgt+ Tregs are established and maintained. Additionally, this study will provide key insights into how transcriptional repressor such as REV- ERB serves as key regulator and tune the function of transcriptional activators in Treg cells. Finally, the outcomes of this study could provide evidence supporting the development of therapeutics targeting REV-ERB for IBD treatment.