Functional Analysis of MicroRNAs and Target Genes in Immune Tolerance

MicroRNA 和免疫耐受靶基因的功能分析

• 批准号: 10159204
• 负责人: DAVID NEMAZEE
• 金额: $ 64.94万
• 依托单位: SCRIPPS RESEARCH INSTITUTE, THE
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-06-05 至 2025-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10159204
• 关键词: Ablation; Anabolism; Animals; Autoimmune Diseases; Autoimmunity; B-Lymphocytes; Biodiversity; Biological Process; Bone Marrow; Chemicals; Code; Communication; Defect; Development; Disease; Dissection; Enzymes; Failure; GADD45A gene; Genes; Genetic; Glycolipids; Graft Rejection; Grant; Hematopoietic System; Immune Tolerance; Immune system; Immunology; In Vitro; Inbred MRL lpr Mice; Knockout Mice; Lymphocyte; MicroRNAs; Modeling; Molecular; Molecular Analysis; Mouse Strains; Mutant Strains Mice; Nature; Pathway interactions; Patients; Peripheral; Play; Process; Proteins; Research; Role; Therapeutic; Transgenic Organisms; Untranslated RNA; autoreactive B cell; cancer immunotherapy; central tolerance; design; diagnostic biomarker; immunoregulation; in vivo; inhibitor/antagonist; lupus-like; mouse model; novel; novel therapeutic intervention; peripheral tolerance; plasma cell differentiation; prevent; systemic autoimmunity; therapeutic target

Project Summary Autoreactive B cells play critical roles in many autoimmune diseases. Multiple immune tolerance checkpoints exist to remove autoreactive B cells or keep them under control. Defects in these checkpoints constitute the basis for the development of autoimmune diseases. Despite intensive study, our understanding of these checkpoints remains incomplete and fragmentary. MicroRNAs (miRNAs) are a new class of small non-coding RNAs that regulate a large diversity of biological processes. Hundreds of miRNAs are expressed in the immune system. While some miRNAs have been shown to play important roles in lymphocyte development and function, the roles of miRNAs in controlling immune tolerance remain poorly understood. We performed in vivo functional analysis of hundreds of miRNAs in the recently established IgMb-macroself mouse model and identified miR-148a as an important regulator of B cell central tolerance and autoimmunity (Nature Immunology 17:433-40, 2016). Further molecular analysis identified 119 target genes regulated by miR-148a in immature B cells. We examined 4 of these target genes and demonstrated that 3 of them, Gadd45a, Bim and Pten, regulate B cell central tolerance. In this proposal, we will 1) further investigate the cellular and molecular mechanisms underlying miR-148a regulation of immune tolerance and autoimmunity, focusing on its role in controlling various B cell tolerance checkpoints and plasma cell differentiation; 2) evaluate the possibility of treating systemic autoimmunity through miR-148a ablation and inhibition by genetic and chemical approaches, respectively, and 3) perform an in vitro functional screen of the other 115 miR-148a target genes to identify novel regulators of B cell tolerance. Our pilot screen has identified B4galt5 as a positive hit. As B4galt5 is a major enzyme in the glycolipid biosynthesis pathway, we speculate that this pathway plays important roles in immune tolerance. Therefore, we will elucidate the function and mechanism of B4galt5 and the glycolipid biosynthesis pathway in controlling B cell tolerance and autoimmunity.

项目概要 自身反应性 B 细胞在许多自身免疫性疾病中发挥着关键作用。多重免疫耐受 检查点的存在是为了清除自身反应性 B 细胞或控制它们。这些检查点的缺陷 是自身免疫性疾病发生发展的基础。尽管进行了深入的研究，我们的 对这些检查点的理解仍然不完整且支离破碎。 MicroRNA（miRNA）是一种新的 一类小非编码 RNA，调节多种生物过程。数百个 miRNA 在免疫系统中表达。虽然一些 miRNA 已被证明在 淋巴细胞的发育和功能，miRNA在控制免疫耐受方面的作用仍然很差 明白了。我们对最近建立的数百个 miRNA 进行了体内功能分析 IgMb-macroself 小鼠模型并确定 miR-148a 是 B 细胞中枢耐受的重要调节因子 和自身免疫（《自然免疫学》17:433-40, 2016）。进一步的分子分析确定了 119 个目标 未成熟 B 细胞中受 miR-148a 调节的基因。我们检查了其中 4 个目标基因并证明 其中 3 个 Gadd45a、Bim 和 Pten 调节 B 细胞中枢耐受性。在本提案中，我们将 1) 进一步 研究miR-148a调节免疫耐受的细胞和分子机制 和自身免疫，重点关注其在控制各种 B 细胞耐受检查点和浆细胞中的作用 差异化； 2) 评估通过 miR-148a 消融治疗系统性自身免疫的可能性 分别通过遗传和化学方法进行抑制，3) 进行体外功能筛选 其他 115 个 miR-148a 靶基因用于鉴定 B 细胞耐受的新调节因子。我们的试点屏幕有 将 B4galt5 确定为阳性命中。由于 B4galt5 是糖脂生物合成途径中的主要酶，我们 推测该途径在免疫耐受中发挥重要作用。因此，我们将阐明 B4galt5和糖脂生物合成途径在控制B细胞耐受中的功能和机制 和自身免疫。