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

基本信息

批准号：
10474916
负责人：
Sergio Armando Villalta
金额：
$ 1.83万
依托单位：
UNIVERSITY OF CALIFORNIA-IRVINE
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-07-01 至 2025-08-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10474916
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

项目摘要

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.

项目概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影响杜氏肌营养不良症（DMD）的发病机制，提供基础开发针对这种毁灭性疾病的新疗法。当前研究的目标是定义调节性 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通过药理学手段来改变疾病的进展。我们提供了强有力的科学前提提出中心假设：Tregs 通过抑制独特的 galectin-3+ 来调节 DMD 的严重程度促进纤维化的肌肉巨噬细胞群。这个假设得到了我们的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+/Spp1+ 填充我们通过单细胞 RNA 测序 (scRNAseq) 鉴定的巨噬细胞； 2) 先前的研究表明 spp1 促进 mdx 小鼠纤维化； 3）mdx小鼠巨噬细胞特异性删除Spp1引起显着变化通过 scRNAseq 评估 PGFRa+ 基质细胞的转录谱； 4) 半乳糖凝集素-3+巨噬细胞当 mdx 小鼠中 Tregs 耗尽时，Treg 会扩增，表明 Tregs 抑制纤维化巨噬细胞 5) mdx 小鼠中 Tregs 的耗竭导致促纤维化基因的表达增加。我们将测试我们的通过解决两个具体目标来实现中心假设。具体目标 1 将定义半乳糖凝集素 3+ 肌肉如何巨噬细胞促进纤维化。具体目标 2 将解决两个子目标：确定分子 Treg 抑制半乳糖凝集素 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 IFNg 产生细胞抑制是 IL-10 依赖性的；在 subaim 2b 中我们将检查 Tregs 的治疗性扩增是否会抑制纤维化。尽管 Spp1 在促进纤维化中发挥作用在 mdx 小鼠中已有记录，但这种病理过程的机制在很大程度上尚不清楚。因此，我们的拟议的研究意义重大，因为它将定义 Spp1 促进肌肉纤维化的细胞基础，并且增进我们对 Tregs 如何减轻肌营养不良症严重程度的理解。拟议的这项研究具有创新性，因为它将定义促进营养不良患者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）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的发展免疫系统的一个部分，在 DMD 中发挥作用，抑制或限制纤维化反应。更远，拟议研究的结果预计将对 DMD 产生重大临床意义，因为可以通过治疗增强Tregs的免疫抑制功能以减轻疾病的严重程度抑制促纤维化炎症反应。