Functional characterization of ubiquitin-like modifier ISG15 in murine enterovirus myocarditis

急性病毒性心肌炎可能导致慢性病毒持续存在和持续的疾病，最终导致心力衰竭，严重并发症和高死亡率，特别是在年轻人中。在急性感染状态下，心肌发生根本性变化：泛素样蛋白（Ubls）ISG 15对蛋白质的翻译后修饰似乎是病毒性疾病中细胞适应的重要调节原则。在进行中的鼠柯萨奇病毒B3（CVB 3）-心肌炎的背景下，发现ISG 15和ISGylating酶的心脏表达以及因此ISGylation在对进行中的疾病敏感的小鼠中延迟。已经在ISG 15-/-小鼠中研究了CVB 3心肌炎，揭示了严重的心肌炎、增加的病毒载量、持续的慢性疾病与病毒持续性，导致高度心肌纤维化和增加的死亡率。为了区分ISG 15蛋白修饰的贡献与分泌的ISG 15的推定细胞因子效应，应在具有不同ISGylation酶缺陷的小鼠中研究CVB 3-心肌炎：将研究具有沉默酶活性的UBE 1 L-/--小鼠和转基因UBP 43-小鼠。在试图鉴定ISG 15的抗病毒作用机制的过程中，研究将致力于鉴定已知干扰CVB 3复制的ISG 15靶标以及CVB 3多蛋白内的ISGylated蛋白底物。ISG 15在CVB 3感染的适应性免疫中的作用将通过CD 4 + T细胞、B细胞以及记忆性CD 8 + T细胞的淋巴细胞转移研究来跟踪。

Acute viral myocarditis may result in chronic virus persistence and ongoing disease eventually leading to heart failure with severe complications and high mortality particularly in young people. Within the acute infectious state the myocardium undergoes fundamental changes: post-translational modifications of proteins by the ubiquitin-like protein (Ubls) ISG15 seem to be an important regulatory principle in the adaptation of cells in viral disease. Within the context of ongoing murine Coxsackievirus B3 (CVB3)- myocarditis the cardiac expression of both ISG15 and ISGylating enzymes, and thus ISGylation were found to be delayed in mice being susceptible to ongoing disease. CVB3 myocarditis has been investigated in ISG15-/- mice revealing severe myocarditis, increased viral load, ongoing chronic disease with virus persistence resulting in high grade myocardial fibrosis, and enhanced mortality. To discriminate the contribution of protein modification with ISG15 from putative cytokine effects of secreted ISG15, CVB3-myocarditis shall be studied in mice with distinct ISGylation-enzyme defects: UBE1L-/--mice and transgenic UBP43-mice with silenced enzyme activity will be studied. In an attempt to identify mechanisms of antiviral action of ISG15, research will aim on the identification of ISG15 targets that are known to interfere with CVB3 replication as well as of ISGylated protein substrates within the CVB3 polyprotein. The role of ISG15 in adaptive immunity in CVB3-infection will be followed by lymphocyte transfer studies of CD4+ T cell, B cells as well as of memory CD8+ T cells.