ACUTE MYOCARDITIS--ROLES OF REOVIRUS AND INTERFERON BETA

急性病毒性心肌炎是一种重要的人类疾病。而当 肠道病毒引起免疫介导的损害，其机制是 其他导致心肌炎的病毒在很大程度上仍未被发现。呼肠孤病毒- 诱导的小鼠心肌炎不是由免疫细胞功能决定的， 为研究非免疫介导性心肌炎提供了一个理想的模型。 我们的数据表明，差异诱导和敏感度 心肌细胞中的干扰素-β是 呼肠孤病毒引起的心肌炎，这些活性是确定的 由呼肠孤病毒核心蛋白参与RNA合成。干扰素提供了一种 抵御病毒感染的关键第一道防线。病毒RNA 合成刺激调节干扰素-β转录的细胞因子。 分泌型干扰素与受体结合并诱导干扰素反应基因 调节干扰素的抗病毒作用，但其中一些需要加倍 搁浅-[DS]RNA激活。对干扰素的诱导和敏感性 贝塔病毒高度依赖于病毒株和细胞类型，然而， 目前还没有关于心脏干扰素对病毒的反应的研究。我们的第一次 假说是呼肠孤病毒对干扰素-β的差异诱导 感染是通过PKR的不同诱导或激活来确定的， IRF-1和/或IRF-2。在具体目标1中，我们将确定PKR (dsRNA激活的蛋白激酶)、IRF-1(干扰素调节因子-1)和/或 IRF-2，每一种都调节其他病毒/细胞中的干扰素-β的诱导 系统，调节呼肠孤病毒对初级心脏中干扰素-β的诱导 心肌细胞培养，我们将使用基因敲除小鼠来研究它们的 在活体中的角色。在具体目标2中，我们将使用另外两种细胞类型 以确定特定细胞的反应。我们的第二个假设是 对干扰素-α/β的不同敏感性是由于不同的 PKR，2‘，5’-寡腺苷的激活和/或敏感性 合成酶和/或RNaseL。在特定目标3中，我们将确定 这三个因素，每一个都需要dsRNA激活来 在其他病毒/细胞系统中的抗病毒作用，介导呼肠孤病毒 原代培养心肌细胞对干扰素-α/β的敏感性 我们将使用基因敲除小鼠来研究它们在体内的作用。在……里面 具体目标4，我们将使用两种额外的细胞类型，如上所述。 呼肠孤病毒提供了一种独特的工具来调查所调用的干扰素应答 由心脏中密切相关的病毒引起。我们的工作将是第一个 作为心脏干扰素反应决定因素的识别细胞因子 和心肌炎。

Acute viral myocarditis is an important human disease. While enteroviruses cause immune-mediated damage, the mechanisms by which other viruses induce myocarditis remain largely unexplored. Reovirus- induced murine myocarditis is not determined by immune cell function, and presents an ideal model for studying nonimmune mediated myocarditis. Our data suggest that differential induction of and sensitivity to interferon-beta (IFN-beta) in cardiac myocytes are determinants of reovirus-induced myocarditis, and that these activities are determined by reovirus core proteins involved in RNA synthesis. IFN provides a critical first line of defense against viral infection. Viral RNA synthesis stimulates cell factors which regulate IFN-beta transcription. Secreted IFN binds receptors and induces IFN-responsive genes which mediate IFN's antiviral effects, but several of these require double stranded-[ds]RNA activation. Both induction of and sensitivity to IFN- beta are highly dependent on virus strain and cell type, and yet, there have been no studies on the cardiac IFN response to viruses. Our first hypothesis is that differential induction of IFN-beta by reovirus infection is determined by differential induction or activation of PKR, IRF-1, and/or IRF-2. In Specific Aim 1, we will determine whether PKR (dsRNA activated protein kinase), IRF-1 (IFN regulatory factor-1) and/or IRF-2, each of which regulate IFN-beta induction in other virus/cell systems, regulate reovirus induction of IFN-beta in primary cardiac myocyte cultures, and we will use knockout mice to investigate their roles in vivo. In Specific Aim 2, we will use two additional cell types to identify cell-specific responses. Our second hypothesis is that differential sensitivity to IFN-alpha/beta is due to differential activation of and/or sensitivity to PKR, 2',5'-oligoadenylate synthetase, and/or RNase L. In Specific Aim 3, we will determine whether these three factors, each of which requires dsRNA activation for antiviral effects in other virus/cell systems, mediate reovirus sensitivity to IFN-alpha/beta in primary cardiac myocyte cultures, and we will use knockout mice to investigate their roles in vivo. In Specific Aim 4, we will use two additional cell types, as above. Reoviruses offer a unique tool to investigate the IFN response invoked by closely related viruses in the heart. Our work will be the first to identity cell factors that are determinants of this cardiac IFN response and myocarditis.