Protein O-GlcNAcylation in Regulatory T Cell Function

调节性 T 细胞功能中的蛋白 O-GlcNAc 酰化

• 批准号: 10284929
• 负责人: Hai-Bin Ruan
• 金额: $ 47.97万
• 依托单位: UNIVERSITY OF MINNESOTA
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-11-23 至 2023-10-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10284929
• 关键词: Acetylation; Autoimmune; Autoimmune Diseases; Biological Process; Cell Line; Cell Lineage; Cell physiology; Cells; Cellular biology; Clinical; Communities; Data; Development; Disease; Enzymes; FOXP3 gene; Face; Genetic Transcription; Graft Rejection; Heterogeneity; Homeostasis; Human; IL2 Signaling Pathway; Immunotherapeutic agent; Immunotherapy; In Vitro; Infection; Inflammation; Instruction; Interleukin 2 Receptor; Interleukin-2; Knock-out; Link; Malignant Neoplasms; Mediating; Metabolism; Modeling; Modification; Molecular; Mus; Mutant Strains Mice; O-GlcNAc transferase; Pathway interactions; Patients; Phosphorylation; Play; Post-Translational Protein Processing; Property; Proteins; Proteome; Proteomics; Receptor Activation; Receptor Signaling; Regulatory T-Lymphocyte; Reporter; Reporting; Role; Serine; Signal Pathway; Signal Transduction; Stat5 protein; Stimulus; Syndrome; T-Cell Receptor; T-Lymphocyte; Testing; Therapeutic; Threonine; Tissues; Translating; Tyrosine Phosphorylation; Ubiquitination; calmodulin-dependent protein kinase II; clinical implementation; clinical practice; effector T cell; human disease; immune self tolerance; in vivo; insight; interest; neoplastic cell; novel; organ transplant rejection; programs; transcription factor; transcriptomics

PROJECT SUMMARY Regulatory T (Treg) cells, characterized by the expression of FOXP3, are a distinct lineage of T lymphocytes that control immunological self-tolerance and tissue homeostasis. These cells are associated with a multitude of human diseases, such as autoimmune disease, inflammation, organ transplant rejection, and some infections and cancers. The biomedical community has developed an intense interest in targeting Treg cells for immunotherapy; however, significant barriers, for example Treg-cell functional heterogeneity and instability, need to be surmounted in order to achieve clinical feasibility. The proposed study aims to understand a novel molecular mechanism that control the stability and function of Treg cells. Our preliminary data have found that a novel O-linked N-Acetylglucosamine (O-GlcNAc) protein modification, activated by T-cell receptor (TCR) signaling, is indispensable for the suppressive function of Treg cells. Treg cell-specific knockout of O-GlcNAc transferase (OGT), the enzyme catalyzing O-GlcNAcylation, does not affect Treg cell lineage specification but results in the development of an aggressive autoimmune syndrome in mice. O-GlcNAcylation modifies and stabilizes FOXP3 protein and transcriptomic analyses have revealed that IL-2/STAT5 signaling is suppressed in OGT-deficient Treg cells. Therefore, we hypothesize that TCR-initiated protein O-GlcNAcylation modulates FOXP3 and STAT5, thereby linking TCR and IL-2 signaling pathways, to regulate Treg cell homeostasis and effector function. In Aim 1, we hypothesize that loss of O-GlcNAcylation destabilizes FOXP3 protein, eliminating the suppressive function of Treg cells and converting Treg cells into effector T cells. We will determine whether O-GlcNAcylation counteracts ubiquitination to stabilize FOXP3 protein, thus maintaining the Treg identity. By generating FOXP3 mutant mice, in which O-GlcNAcylation is specifically abolished, we will test whether FOXP3 O-GlcNAcylation is required for the suppressive activity of Treg cells. In Aim 2, we propose to examine the effect of STAT5 O-GlcNAcylation on Treg cell suppressive function. We will test the hypothesis that O-GlcNAcylation controls IL-2-stimulated STAT5 activation in Treg cells and FOXP3 and STAT5 act cooperatively to mediate the effect of protein O-GlcNAcylation in Treg cell function. In Aim 3, we will identify the molecular link between TCR and O-GlcNAcylation in Treg cells. We will test the hypothesis that TCR signaling promotes protein O- GlcNAcylation and Treg cell suppressive activity in a Ca2+/CaMKII-dependent manner. Lastly, through unbiased O-GlcNAc proteomics, we will characterize TCR-regulated protein O-GlcNAcylation profile and identify potential complementary mechanisms for O-GlcNAc-mediated Treg cell function. The proposed study will stimulate the opening of a new avenue in therapeutics directed to activate and maintain Treg cells for immunotherapy.

项目概要 调节性 T (Treg) 细胞以表达 FOXP3 为特征，是一种独特的 T 淋巴细胞谱系 控制免疫自我耐受和组织稳态。这些细胞与许多 人类疾病，例如自身免疫性疾病、炎症、器官移植排斥和某些感染 和癌症。生物医学界对靶向 Treg 细胞产生了浓厚的兴趣 免疫疗法；然而，显着的障碍，例如Treg细胞功能异质性和不稳定性， 为了实现临床可行性，需要克服这些困难。拟议的研究旨在了解小说 控制Treg细胞稳定性和功能的分子机制。我们的初步数据发现， 新型 O-连接 N-乙酰氨基葡萄糖 (O-GlcNAc) 蛋白修饰，由 T 细胞受体 (TCR) 激活 信号传导对于 Treg 细胞的抑制功能是不可或缺的。 O-GlcNAc 的 Treg 细胞特异性敲除 转移酶 (OGT) 是一种催化 O-GlcNAc 酰化的酶，不影响 Treg 细胞谱系规范，但 导致小鼠出现侵袭性自身免疫综合征。 O-GlcNAc 酰化修饰和 稳定 FOXP3 蛋白，转录组分析表明 IL-2/STAT5 信号传导在 OGT 缺陷的 Treg 细胞。因此，我们假设 TCR 启动蛋白 O-GlcNAcNA 酰化调节 FOXP3 和 STAT5，从而连接 TCR 和 IL-2 信号通路，调节 Treg 细胞稳态和 效应器功能。在目标 1 中，我们假设 O-GlcNAc 酰化的丧失会破坏 FOXP3 蛋白的稳定性，从而消除 Treg 细胞的抑制功能以及将 Treg 细胞转化为效应 T 细胞。我们将确定是否 O-GlcNAc 酰化抵消泛素化以稳定 FOXP3 蛋白，从而维持 Treg 身份。经过 生成 FOXP3 突变小鼠，其中 O-GlcNAcylation 被特异性废除，我们将测试 FOXP3 是否 O-GlcNAc 酰化是 Treg 细胞抑制活性所必需的。在目标 2 中，我们建议检查效果 STAT5 O-GlcNAcylation 对 Treg 细胞抑制功能的影响。我们将检验以下假设：O-GlcNAcylation 控制 Treg 细胞中 IL-2 刺激的 STAT5 激活，FOXP3 和 STAT5 协同作用介导 蛋白质 O-GlcNAc 酰化对 Treg 细胞功能的影响。在目标 3 中，我们将确定 TCR 之间的分子联系 和 Treg 细胞中的 O-GlcNAc 酰化。我们将检验 TCR 信号传导促进蛋白 O-的假设 以 Ca2+/CaMKII 依赖性方式抑制 GlcNAc 化和 Treg 细胞活性。最后，通过不偏不倚的 O-GlcNAc 蛋白质组学，我们将表征 TCR 调节蛋白 O-GlcNAc 酰化谱并鉴定潜在的 O-GlcNAc 介导的 Treg 细胞功能的互补机制。拟议的研究将刺激 开辟了一条新的治疗途径，旨在激活和维持 Treg 细胞以进行免疫治疗。