Novel macrophage and regulatory T cell interactions that promote the pathogenesis of Duchenne muscular dystrophy

促进杜氏肌营养不良症发病机制的新型巨噬细胞和调节性 T 细胞相互作用

• 批准号: 10267201
• 负责人: Sergio Armando Villalta
• 金额: $ 42.29万
• 依托单位: UNIVERSITY OF CALIFORNIA-IRVINE
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-30 至 2025-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10267201
• 关键词: Ablation; Acute; Address; Antibodies; Biological Assay; Cell Communication; Cells; Chronic; Clinical; Complex; Data; Deposition; Development; Disease; Disease Progression; Duchenne muscular dystrophy; Extracellular Matrix; Fibrosis; Foundations; Galectin 3; Gene Expression Profile; Genes; Goals; Histologic; Immune; Immune system; Immunogenetics; Infiltration; Inflammation; Inflammatory; Inflammatory Response; Injury; Interferons; Interleukin-10; Interleukin-2; Investigational Therapies; Lead; Lymphoid; Mediating; Mediator of activation protein; Molecular; Mus; Muscle; Muscular Dystrophies; Myelogenous; Natural regeneration; Operating System; Outcome; Outcome Study; Pathogenesis; Pathologic Processes; Pathway interactions; Pharmacology; Population; Process; Production; Regulatory T-Lymphocyte; Reporting; Research; Role; Severities; Severity of illness; Signal Transduction; Stromal Cells; System; Testing; Therapeutic; Time; base; immunoregulation; innovation; innovative technologies; insight; macrophage; mdx mouse; muscle degeneration; muscle regeneration; novel; novel strategies; osteopontin; response; single-cell RNA sequencing; stem

PROJECT SUMMARY The long-term goal of our research is to determine how the immune system interfaces with cells in the dystrophic niche to impact the pathogenesis of Duchenne muscular dystrophy (DMD), to provide a foundation for developing novel treatments for this devastating disease. The objective of the current study is to define how regulatory T cells (Treg) regulate macrophage-stromal interactions in muscle, and how these interactions can be pharmacologically manipulated to alter disease progression. We provide strong scientific premise for proposing the central hypothesis that Tregs regulate the severity of DMD by suppressing a distinct galectin-3+ muscle macrophage population that promotes fibrosis. This hypothesis is supported by our preliminary data and prior research, showing that 1) dystrophic muscle is populated by a putative fibrogenic galectin-3+/Spp1+ macrophage that we identified by single-cell RNA sequencing (scRNAseq); 2) prior research showing that spp1 promotes fibrosis in mdx mice; 3) macrophage-specific deletion of Spp1 in mdx mice causes remarkable changes in the transcriptional profile of PGFRa+ stromal cells, as assessed by scRNAseq; 4) galectin-3+ macrophages are expanded when Tregs are depleted in mdx mice, suggesting that Tregs suppress fibrogenic macrophages and 5) depletion of Tregs in mdx mice causes an increased expression of pro-fibrotic genes. We will test our central hypothesis by addressing two specific aims. Specific aim 1 will define how galectin-3+ muscle macrophages promote fibrosis. Two subaims will be addressed under specific aim 2, identify the molecular basis for Treg suppression of galectin-3+ muscle macrophages. In subaim 2a we will determine whether the Treg-mediated suppression of IFNg-producing cells is IL-10 dependent; and in subaim 2b we will examine whether the therapeutic expansion of Tregs suppresses fibrosis. Although a role for Spp1 in promoting fibrosis in mdx mice has been documented, a mechanism for this pathological process is largely unknown. Thus, our proposed study is significant as it will define the cellular basis by which Spp1 promotes muscle fibrosis, and advance our understanding of how Tregs ameliorate the severity of muscular dystrophy. The proposed research is innovative because it will define mechanisms of cellular cross talk that promote fibrosis in dystrophic muscles. The proposed studies use innovative technologies (e.g. scRNAseq) and experimental therapeutics (e.g. IL-2c) that will provide the framework for developing novel approaches to inhibit the development of fibrosis. These potential discoveries will advance the field by establishing interactions between the lymphoid and myeloid compartment of the immune system that operate in DMD to suppress or limit fibrogenic responses. Further, findings from the proposed studies are expected to have significant clinical implications for DMD, as the immunosuppressive function of Tregs can be therapeutically augmented to ameliorate disease severity by inhibiting pro-fibrotic inflammatory responses.

项目摘要 我们研究的长期目标是确定免疫系统如何与细胞中的细胞互动 营养不良的生态位影响杜兴（Duchenne）肌肉营养不良（DMD）的发病机理，以提供基础 用于为这种毁灭性疾病开发新的治疗方法。当前研究的目的是定义 调节性T细胞（Treg）如何调节肌肉中的巨噬细胞相互作用，以及这些相互作用如何 可以在药理上操纵以改变疾病进展。我们为科学前提提供了强大的前提 提出了一个中心假设，即Tregs通过抑制明显的Galectin-3+来调节DMD的严重程度 促进纤维化的肌肉巨噬细胞种群。该假设得到了我们的初步数据和 先前的研究，表明1）营养不良的肌肉被推定的纤维蛋白-3+/spp1+ 我们通过单细胞RNA测序（SCRNASEQ）确定的巨噬细胞； 2）事先研究表明SPP1 促进MDX小鼠的纤维化； 3）MDX小鼠中SPP1的巨噬细胞特异性缺失会引起显着变化 如Scrnaseq评估，在PGFRA+基质细胞的转录曲线中； 4）Galectin-3+巨噬细胞 当Treg在MDX小鼠中耗尽时，会扩大 5）MDX小鼠中Treg的耗竭会导致促纤维化基因的表达增加。我们将测试我们的 中央假设通过解决两个具体目标。特定的目标1将定义Galectin-3+肌肉 巨噬细胞促进纤维化。在特定目标2下将解决两个子iaim，确定分子 dreg抑制半乳糖素3+肌肉巨噬细胞的基础。在Subaim 2a中，我们将确定是否 Treg介导的产生IFNG的细胞的抑制是IL-10依赖性的。在Subaim 2B中，我们将检查 Treg的治疗膨胀是否抑制纤维化。虽然SPP1在促进纤维化中的作用 在MDX小鼠已被记录下来，这种病理过程的机制在很大程度上未知。因此，我们的 拟议的研究很重要，因为它将定义SPP1促进肌肉纤维化的细胞基础，并且 促进我们对Treg如何改善肌肉营养不良的严重程度的理解。提议 研究具有创新性，因为它将定义促进营养不良的纤维化的细胞交叉谈话机制 肌肉。拟议的研究使用创新技术（例如SCRNASEQ）和实验疗法（例如 IL-2C）将为开发抑制纤维化发展的新方法提供框架。 这些潜在的发现将通过建立淋巴机和髓样的相互作用来推进该领域 在DMD中运行以抑制或限制纤维化反应的免疫系统的隔室。更远， 预计拟议研究的发现对DMD具有显着的临床意义，因为 Treg的免疫抑制功能可以通过治疗性增强以改善疾病的严重程度 抑制促纤维化炎症反应。