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

SARS-CoV2 是一种高度传染性的新型人类冠状病毒，可引起冠状病毒病 2019 年（新冠肺炎 (COVID-19)）。目前美国已有超过740万人确诊感染 SARS-CoV2 和超过 215,000 人死亡。严重的 COVID-19 的特点是肺部和 全身炎症和多器官功能障碍，对老年人的影响尤为严重 患者。 SARS-CoV2 引发如此严重的发病机制的机制尚不清楚 明白了。最近的临床研究表明，细胞死亡，特别是诱导 坏死性凋亡可能是严重 COVID-19 疾病的预测因子。主机的机制 限制坏死性凋亡尚不清楚。在初步数据中，我们已经表明干扰素诱导 蛋白质 ISG15 充当坏死性凋亡及其下游炎症的负调节因子 病毒感染期间的反应。在本提案中，我们将测试 SARS-CoV2 的假设 诱导坏死性凋亡，并且 ISG15 作为呼吸系统坏死性凋亡的负调节因子 上皮细胞。我们将使用体外原代气管上皮培养物 (hTEC) 和体内 小鼠适应了 SARS-CoV2 动物模型，提出了几个问题，包括：1) SARS- CoV2诱导呼吸道上皮细胞坏死性凋亡； 2) ISG15是否调节坏死性凋亡细胞 死亡以及呼吸道上皮细胞中促炎细胞因子/趋化因子的产生 SARS-CoV2 感染期间？ 3) 坏死性凋亡及其 ISG15 的调节是否有助于 SARS-CoV2 发病机制？总的来说，我们的研究将为我们提供重要的见解 SARS-CoV2 感染的发病机制，并提供对潜在机制的潜在见解 严重疾病，这可能会引导人们努力开发诊断标记物和未来 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.