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

SARS-CoV2是一种高传染性的新型人类冠状病毒，可导致冠状病毒疾病 2019年(新冠肺炎)。目前，美国已有超过740万人确认感染了 SARS-CoV2和超过21.5万人死亡。重症新冠肺炎的特点是肺性和 全身性炎症和多器官功能障碍，不成比例地影响老年人 病人。SARS-CoV2引发如此严重的致病机制尚不清楚 明白了。最近的临床研究表明，细胞死亡，特别是诱导 坏死性上睑下垂，可能是严重新冠肺炎病的预测因素。主办方通过的机制 限制坏死性上睑下垂的原因尚不清楚。在初步数据中，我们已经表明干扰素诱导 ISG15蛋白是坏死性下垂及其下游炎症的负调控因子 在病毒感染期间的反应。在这项提案中，我们将检验SARS-CoV2病毒的假设 ISG15对呼吸系统坏死性下垂的负性调节作用 上皮细胞。我们将使用体外原代气管上皮细胞(HTECs)和体内的 小鼠采用SARS-CoV2动物模型来提出几个问题，包括：1)SARS-CoV2 CoV2诱导呼吸道上皮细胞坏死性下垂；2)ISG15是否调节坏死性上皮细胞 呼吸道上皮细胞死亡与致炎细胞因子/趋化因子的产生 在SARS-CoV2感染期间？3)坏死性下垂及其被ISG15调控是否有助于 SARS-CoV2的发病机制？总体而言，我们的研究将为我们提供对 SARS-CoV2感染的发病机制和潜在的潜在机制 严重疾病，这可能会指导诊断标志物的发展和未来的努力 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.