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相互作用， 营养不良生态位对杜氏肌营养不良症（DMD）发病机制的影响，提供依据 为这种毁灭性的疾病开发新的治疗方法。本研究的目的是确定 调节性T细胞（Treg）如何调节肌肉中的巨噬细胞-基质相互作用，以及这些相互作用如何 可以被人为操纵来改变疾病的进展。我们提供了强有力的科学前提， 提出了一个中心假设，即TdR通过抑制一种独特的半乳糖凝集素-3+来调节DMD的严重程度， 促进纤维化的肌肉巨噬细胞群。这一假设得到了我们初步数据的支持， 先前的研究表明，1）营养不良的肌肉由假定的纤维化半乳糖凝集素-3+/Spp 1+占据 我们通过单细胞RNA测序（scRNAseq）鉴定的巨噬细胞; 2）先前的研究表明spp 1 促进mdx小鼠的纤维化; 3）mdx小鼠中Spp 1的巨噬细胞特异性缺失引起显著变化 在PGFRa+基质细胞的转录谱中，如通过scRNAseq评估的; 4）半乳糖凝集素-3+巨噬细胞 在mdx小鼠中，当TdR耗尽时，TdR扩增，表明TdR抑制纤维化巨噬细胞， 和5）mdx小鼠中TdR的消耗导致促纤维化基因的表达增加。我们将测试我们的 中心假设，解决两个具体目标。具体目标1将定义半乳糖凝集素-3+肌肉 巨噬细胞促进纤维化。在具体目标2下将讨论两个子目标， 半乳糖凝集素-3+肌肉巨噬细胞的Treg抑制的基础。在子目标2a中，我们将确定 Treg介导的IFN-γ产生细胞的抑制是IL-10依赖性的;在子目标2b中，我们将研究 THBE的治疗扩展是否抑制纤维化。虽然Spp 1在促进纤维化中的作用 在mdx小鼠中，这种病理过程的机制在很大程度上是未知的。所以我们 拟议的研究是重要的，因为它将定义Spp 1促进肌肉纤维化的细胞基础， 促进我们对TdR如何改善肌营养不良症严重程度的理解。拟议 这项研究是创新性的，因为它将确定促进营养不良性疾病中纤维化的细胞串扰机制。 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），这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和骨髓之间的相互作用来推进该领域 在DMD中起作用以抑制或限制纤维化反应的免疫系统的区室。此外，本发明还 从拟议的研究结果预计将有显着的临床意义的DMD，因为 通过以下方法，可以在治疗上增强THBE免疫抑制功能以改善疾病严重程度 抑制促纤维化炎症反应。