A spatially resolved molecular atlas of acute viral myocarditis at single-cell resolution

病毒性心肌炎是一种异质性疾病，难以研究和诊断。因为 急性病毒性心肌炎的异质性以及 心肌内膜活检（被认为是诊断病毒性心肌炎的金标准）， 了解这种疾病的分子发病机制，特别是在婴儿和新生儿中， 肌内膜活检很少进行。心脏内对病毒应答的特定细胞 感染，他们的反应的性质，以及这种反应的时空分布是不是很清楚。 从细胞和分子水平更好地了解心脏对病毒感染的时空反应 水平将提供急需的洞察病理过程，驱动积极的炎症过程 心脏病毒感染后出现的症状 对病毒性心肌炎的分子发病机制缺乏了解，部分原因是缺乏工具， 以单细胞分辨率研究复杂天然组织中的病毒感染。在这里，我们将使用创新的空间 解析转录组学、单细胞RNA测序（scRNA-seq）工具和生物信息学， 经典病毒学技术和小鼠模型来研究哺乳动物正呼肠孤病毒（REOV）中的心肌炎。 我们有三个目标：在目标1中，我们将研究决定REOV感染结果的病毒和宿主因素 心脏组织。在目标2中，我们将确定在REOV诱导的心肌炎中的焦亡作用。在目标3中， 将联合收割机结合我们的心肌炎高分辨率单细胞图谱和液体活检的原则， 无细胞RNA开发高度特异性的病毒性心肌炎血液生物标志物，从而解决了一个紧迫的， 未满足的医疗需求我们预计我们的研究将提供前所未有的深入了解病毒的病理生物学 心肌炎我们的实验将阐明在复杂的心脏组织中哪些细胞类型被感染， 感染成功与否取决于细胞状态和细胞环境。我们将阐明 我们将探讨免疫细胞反应是否以及如何从 宿主防御到宿主损伤。我们将探讨感染细胞对未感染的旁观者细胞的影响， 物理接近，我们将绘制介导这种旁观者效应的细胞相互作用。我们还将 探索感染者和未感染者先天免疫应答的空间和细胞类型异质性 心脏组织 这些研究的成功实施将导致新的方法和分子工具来研究病毒 心肌炎和其他病毒性疾病，并可能确定新的诊断方法和治疗目标， 急性病毒性心肌炎

Viral myocarditis is a heterogeneous disease that is difficult to study and diagnose. Because of the heterogeneous nature of acute viral myocarditis and the difficulty and low diagnostic sensitivity of endomyocardial biopsies (considered the gold standard for diagnosis of viral myocarditis), there is limited knowledge of the molecular pathogenesis of this disease, particularly in infants and neonates where endomyocardial biopsies are less often performed. The specific cells within the heart that respond to viral infection, the nature of their responses, and the spatiotemporal distribution of such responses are not well known. A better understanding of the spatiotemporal response of the heart to viral infection at the cellular and molecular level will provide much needed insight into the pathological processes that drive the active inflammatory process that ensues following viral infection of the heart. The lack of understanding of the molecular pathogenesis of viral myocarditis is in part due to the lack of tools to investigate viral infection in complex native tissues at single cell-resolution. Here we will use innovative spatially resolved transcriptomics, single-cell RNA sequencing (scRNA-seq) tools and bioinformatics, in conjunction with classical virology techniques, and mouse models to study myocarditis in mammalian orthoreovirus (REOV). We have three aims: In Aim 1, we will study the viral and host factors that define the outcome of REOV infection of cardiac tissues. In Aim 2, we will determine the role of pyroptosis in REOV-induced myocarditis. In Aim 3, we will combine our high-resolution single-cell atlas of myocarditis with the principles of liquid biopsies based on cell-free RNA to develop highly specific blood biomarkers of viral myocarditis, thereby addressing an urgent and unmet medical need. We anticipate our studies will provide unprecedented insight into the pathobiology of viral myocarditis. Our experiments will clarify which cell types are infected in complex cardiac tissues and will reveal how infection success depends on both cell state and cellular environment. We will elucidate the role for endothelial cells in viral myocarditis and we will explore whether and how immune cell responses switch from host defense to host injury. We will explore the effects of infected cells on uninfected bystander cells in close physical proximity, and we will map the cellular interactions that mediate this bystander effect. We will also explore the spatial and cell type heterogeneity of innate immune responses within infected and uninfected cardiac tissues. Successful implementation of these studies will lead to new approaches and molecular tools to study viral myocarditis and other viral diseases and may identify novel diagnostic approaches and therapeutic targets for acute viral myocarditis.