Analyzing the effects of type I interferons in the enterovirus-infected heart

分析 I 型干扰素对肠道病毒感染心脏的影响

• 批准号: 9198190
• 负责人: J. Lindsay Whitton
• 金额: $ 67.52万
• 依托单位: SCRIPPS RESEARCH INSTITUTE, THE
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-02-01 至 2020-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9198190
• 关键词: Ablation; Acute; Adaptive Immune System; Address; Affect; Antiviral Agents; Biological; Cardiac; Cardiac Myocytes; Cells; Coxsackie Viruses; Data; Dilated Cardiomyopathy; Disease; Enterovirus; Genes; Grant; Heart; Hematopoietic; Human; Immune response; Infection; Inflammation; Interferon Type I; Interferons; Knockout Mice; Mediating; Modeling; Mus; Mutation; Myocardial; Myocarditis; Myocardium; Natural Immunity; Organ; Outcome; Phase; Play; Predisposition; Production; Publishing; RNA; Resistance; Role; Signal Transduction; Source; TLR3 gene; Time; Variant; Viral; Virus; Virus Diseases; Virus Replication; Work; cell type; chronic myocarditis; in vivo; knockout gene; prevent; public health relevance; receptor; sensor; tissue culture; viral myocarditis

 DESCRIPTION (provided by applicant): Viral myocarditis is a relatively common, sometimes severe, and potentially fatal disorder, and one of the most frequent causes is the enterovirus coxsackievirus B3 (CVB3). CVB3 infection of the heart is highly focal, even in mice lacking an intact adaptive immune system, suggesting that innate immunity may hold the virus in check. Type I interferons (T1IFNs) are an obvious candidate, and are known to positively affect the outcome of enteroviral myocarditis. However, there is much that we do not know about how the effects of T1IFNs are mediated. For example, one very well-respected group has argued that T1IFNs may not even act within the heart, and that their cardioprotective effects may be indirect, resulting from the suppression of viral replication in other organs. We have generated mice in which the T1IFN receptor (T1IFNR) can be ablated in vivo specifically from cardiomyocytes, and our unpublished data show unequivocally that T1IFNs do, in fact, act directly on cardiomyocytes during CVB3 infection, and play a substantial role in viral titers and CVB-induced disease. But many questions remain. How do they do this - what genes are activated by T1IFNs in infected (and in uninfected) cardiomyocytes? We shall identify the cardiomyocyte genes that are directly responsive to T1IFN signals in vivo. CVB3 also causes chronic myocarditis and dilated cardiomyopathy, which are related to RNA persistence in the heart, and our inducible gene knockout model confers a key experimental advantage in this regard; we can establish persistent CVB3 infection in genetically-intact mice that do not develop disease, and afterwards ablate T1IFN signaling into cardiomyocytes, to ask: do these mice now develop disease, i.e. might resistance/susceptibility to chronic myocarditis / DCM be related to T1IFN signaling in cardiomyocytes? Our preliminary data indicate that the effects of T1IFN during CVB3 infection of the heart may be biphasic, and we hypothesize that the two temporal phases are defined by differing cellular sources of the T1IFNs. So, Aims 2 and 3 extend our focus to address the production of T1IFNs. What cells serve as the source of the T1IFNs? Plasmacytoid DCs (pDCs) are obvious candidates, but recent work has raised questions about their true in vivo role during viral infection, and also has shown that TLR3-dependent production of T1IFNs may be more important in controlling virus infection. The proposal has three Specific Aims Aim 1. To investigate the in vivo consequences of type 1 IFN signaling in cardiomyocytes during acute and persistent CVB3 infection. Aim 2. To evaluate the role of pDCs during CVB3 infection Aim 3. To determine why TLR3 plays a key role in CVB3-induced myocarditis.

 描述（由申请人提供）：病毒性心肌炎是一种相对常见、有时严重且可能致命的疾病，最常见的原因之一是肠道病毒柯萨奇病毒 B3 (CVB3)。即使在缺乏完整适应性免疫系统的小鼠中，CVB3 心脏感染也是高度集中的，这表明先天免疫可能会抑制病毒。 I 型干扰素 (T1IFN) 是一个明显的候选者，已知对肠道病毒性心肌炎的结果有积极影响。然而，关于 T1IFN 的作用是如何介导的，我们还有很多不了解的地方。例如，一个备受尊敬的团体认为，T1IFN 甚至可能不在心脏内起作用，并且它们的心脏保护作用可能是间接的，是由于抑制其他器官中的病毒复制而产生的。我们已经培育出T1IFN受体（T1IFNR）可以在体内特异性地从心肌细胞中消除的小鼠，并且我们未发表的数据明确表明，T1IFN实际上在CVB3感染期间直接作用于心肌细胞，并在病毒滴度和CVB诱导的疾病中发挥重要作用。但仍然存在许多问题。他们是如何做到这一点的——感染（和未感染）的心肌细胞中哪些基因被 T1IFN 激活？我们将鉴定体内直接响应 T1IFN 信号的心肌细胞基因。 CVB3还会引起慢性心肌炎和扩张型心肌病，这与心脏中的RNA持久性有关，而我们的诱导基因敲除模型在这方面赋予了关键的实验优势；我们可以在未发病的遗传完整的小鼠中建立持续的CVB3感染，然后将T1IFN信号消融到心肌细胞中，以询问：这些小鼠现在是否会发病，即对慢性心肌炎/DCM的抵抗/易感性可能与心肌细胞中的T1IFN信号有关吗？我们的初步数据表明，CVB3 感染心脏期间 T1IFN 的影响可能是双相的，我们假设这两个时间阶段是由 T1IFN 的不同细胞来源定义的。因此，目标 2 和 3 将我们的重点扩展到解决 T1IFN 的生产。哪些细胞是 T1IFN 的来源？浆细胞样 DC (pDC) 是明显的候选者，但最近的研究对它们在病毒感染期间的体内真正作用提出了疑问，并且还表明 TLR3 依赖性 T1IFN 的产生可能在控制病毒感染方面更重要。该提案有三个具体目标 1. 研究急性和持续 CVB3 感染期间心肌细胞中 1 型 IFN 信号传导的体内后果。目标 2. 评估 pDC 在 CVB3 感染过程中的作用 目标 3. 确定为什么 TLR3 在 CVB3 诱导的心肌炎中发挥关键作用。