Regulation of Cell Death and Inflammation by ISG15 during SARS-CoV2 Infection

SARS-CoV 2是一种高度传染性的新型人类冠状病毒，可导致冠状病毒疾病 2019年（COVID-19）。目前，美国已有超过740万人确认感染了 SARS-CoV 2和超过215，000人死亡。严重的COVID-19的特征是肺部和 全身性炎症和多器官功能障碍，严重影响老年人 患者SARS-CoV 2引发这种严重发病机制的机制尚不清楚， 明白最近的临床研究表明，细胞死亡，特别是诱导 坏死性凋亡可能是严重COVID-19疾病的预测因子。宿主通过这种机制 是否限制了坏死性凋亡尚不清楚。在初步的数据中，我们已经表明干扰素诱导的 ISG 15蛋白是坏死性凋亡及其下游炎症反应的负调节因子， 病毒感染时的反应。在这项提议中，我们将检验SARS-CoV 2 诱导坏死性凋亡，ISG 15在呼吸系统中作为坏死性凋亡的负调节剂发挥作用， 上皮细胞我们将使用体外原代气管上皮细胞培养物（hTEC）和体内培养物。 小鼠适应SARS-CoV 2动物模型提出了几个问题，包括：1）SARS- CoV 2诱导呼吸道上皮细胞坏死性凋亡; 2）ISG 15是否调节坏死性细胞凋亡 呼吸道上皮细胞中的死亡以及促炎细胞因子/趋化因子产生 在SARS-CoV 2感染期间？3)坏死性凋亡和ISG 15对其的调节是否有助于 SARS-CoV 2发病机制？总的来说，我们的研究将提供重要的见解， SARS-CoV 2感染的发病机制，并提供潜在的洞察机制， 严重的疾病，这可能会直接努力发展诊断标志物和未来 对策

SARS-CoV2 is a highly contagious, novel human coronavirus that causes coronavirus disease 2019 (COVID-19). Currently over 7.4 million people in the US have confirmed infection with SARS-CoV2 and over 215,000 have died. Severe COVID-19 is characterized by pulmonary and systemic inflammation and multi-organ dysfunction, which disproportionally affects elderly patients. The mechanism by which SARS-CoV2 triggers such severe pathogenesis is poorly understood. Recent clinical studies have suggested that cell death, especially the induction of necroptosis, may be predictor of severe COVID-19 disease. The mechanism by which the host restricts necroptosis is unclear. In the preliminary data we have shown that the interferon induced protein, ISG15, acts as a negative regulator of necroptosis and its downstream inflammatory responses during viral infection. In this proposal we will test the hypothesis that SARS-CoV2 induces necroptosis and that ISG15 functions as a negative regulator of necroptosis in respiratory epithelial cells. We will use in vitro primary tracheal epithelial cultures (hTECs) and an in vivo mouse adapted SARS-CoV2 animal model to ask several questions including: 1) Does SARS- CoV2 induce necroptosis in respiratory epithelial cells; 2) Does ISG15 modulate necroptotic cell death as well as proinflammatory cytokine/chemokine production in respiratory epithelial cells during SARS-CoV2 infection?; 3) Does necroptosis and its regulation by ISG15 contribute to SARS-CoV2 pathogenesis? Overall, our studies will provide important insight into the pathogenesis of SARS-CoV2 infection and provide potential insight into mechanisms underlying severe disease, which may direct efforts toward the development of diagnostic markers and future countermeasures.