High-dimensional mass imaging of muscle for the mechanistic study of T cells in inclusion body myositis

项目总结/摘要 散发性包涵体肌炎（IBM）是一种罕见的，获得性肌肉疾病的病因不明。我们的长期 目的是确定T细胞如何参与IBM的发病机制。T细胞经历克隆扩增， 细胞分化，但失去了增殖能力，并表现出衰老的特征，包括生产 促进肌肉细胞死亡的溶细胞蛋白（如穿孔素和颗粒酶）。此外，衰老的T细胞是 对细胞凋亡的抗性，这可以解释IBM的治疗难治性。当前的目标 这项研究的目的是确定高分化T细胞衰老的分子特征，并将这些特征联系起来 与IBM的临床测量。此外，将使用药理学方法来定义机制 调节IBM中的T细胞衰老。我们将检验衰老的肌肉T细胞促进 IBM的严重性和进展。在初步研究中，我们发现KRLG 1 + CD 8+的频率 IBM患者血液中的衰老样T细胞升高。尽管KRLG 1 + CD 8 + T细胞与 疾病持续时间，它们与IBM的严重程度无关。鉴于免疫反应可能会有很大的不同 在血液和受影响的组织之间，通过免疫反应的高分辨率分析进行机制研究， 在IBM中，需要肌肉来确定衰老T细胞和IBM之间的关系。核心假设 将通过解决两个具体目标来测试这项调查。在具体目标1中，我们将定义 衰老肌肉T细胞的特征及其与疾病严重程度和进展的关系。缺乏工具 对肌肉中的T细胞群体进行严格的表型分析使得研究这些细胞并确定其 功能在IBM因此，创新的高维质量成像平台将用于解决这一问题 限制，并确定衰老T细胞和IBM之间的关系。具体目标2： 确定衰老清除疗法消除衰老CD 8 + T细胞的能力，这将提供机制见解 对IBM期间T细胞衰老的调节。这项拟议的研究意义重大，因为它将建立一个 这是定义IBM中失调的T细胞反应功能的基础。此外，它将提供初步的 证据来支持一种新的治疗方法对这种疾病的测试。拟议的研究是 它也是创新的，因为它使用了先进的大规模成像技术来严格询问衰老的人， IBM中T细胞的表型。衰老清除药物的使用也标志着一种创新的靶向方法 功能失调的T细胞和定义衰老T细胞在IBM中的作用。总的来说，拟议的工作承诺 以促进我们对免疫系统在IBM发病机制中的作用的理解，并可能具有 通过指导治疗和/或治愈IBM的新策略的开发来产生广泛的影响。

PROJECT SUMMARY/ABSTRACT Sporadic inclusion body myositis (IBM) is a rare, acquired muscle disease of unknown etiology. Our long-term goal is to define how T cells contribute to the pathogenesis of IBM. T cells undergo clonal expansion and differentiation but lose their proliferative capacity and exhibit characteristics of senescence, including production of cytolytic proteins (e.g. perforin and granzyme) that promote muscle cell death. Further, senescent T cells are resistance to apoptosis, which may explain the treatment refractory nature of IBM. The objective of the current study is to define molecular attributes of senescence in highly-differentiated T cells, and correlate these features with clinical measures of IBM. Further, a pharmacological approach will be used to define the mechanism regulating T cell senescence in IBM. We will test the central hypothesis that senescent muscle T cells promote the severity and progression of IBM. In preliminary studies, we show that the frequency of KRLG1+CD8+ senescent-like T cells was elevated in the blood of IBM patients. Although KRLG1+CD8+ T cells correlated with disease duration, they did not correlate with the severity of IBM. Given that an immune response can vastly differ between blood and the affected tissue, mechanistic studies with high-resolution profiling of the immune response in IBM muscle are needed to determine relationships between senescent T cells and IBM. The central hypothesis of this investigation will be tested by addressing two specific aims. In specific aim 1, we will define the molecular features of senescent muscle T cells and their relationship to disease severity and progression. The lack of tools to rigorously phenotype T cell populations in muscle has made it difficult to study these cells and determine their function in IBM. Thus, an innovative high-dimensional mass imaging platform will be used to address this limitation, and determine the relationship between senescent T cells and IBM. In specific aim 2, we will determine the ability of senolytic therapy to ablate senescent CD8+ T cells, which will provide mechanistic insight on the regulation of T cell senescence during IBM. The proposed study is significant as it will establish a foundation for defining the function of dysregulated T cell responses in IBM. Further, it will provide preliminary evidence to support the testing of a novel therapeutic approach for this disease. The proposed research is also innovative as it uses cutting-edge advancements in mass imaging to rigorously interrogate the senescent phenotype of T cells in IBM. The use of senolytic drugs also marks an innovative approach for targeting dysfunctional T cells and defining the role of senescent T cells in IBM. Collectively, the proposed work promises to advance our understanding of the role of the immune system in the pathogenesis of IBM, and may have a broad impact by guiding the development of novel strategies to treat and/or cure IBM.