Our therapeutic arsenal against viruses is very limited and the current pandemic of SARS-CoV-2 highlights the critical need for effective antivirals against emerging coronaviruses. Cellular assays allowing a precise quantification of viral replication in high-throughput experimental settings are essential to the screening of chemical libraries and the selection of best antiviral chemical structures. To develop a reporting system for SARS-CoV-2 infection, we generated cell lines expressing a firefly luciferase maintained in an inactive form by a consensus cleavage site for the viral protease 3CL^Pro of coronaviruses, so that the luminescent biosensor is turned on upon 3CL^Pro expression or SARS-CoV-2 infection. This cellular assay was used to screen a metabolism-oriented library of 492 compounds to identify metabolic vulnerabilities of coronaviruses for developing innovative therapeutic strategies. In agreement with recent reports, inhibitors of pyrimidine biosynthesis were found to prevent SARS-CoV-2 replication. Among the top hits, we also identified the NADPH oxidase (NOX) inhibitor Setanaxib. The anti-SARS-CoV-2 activity of Setanaxib was further confirmed using ACE2-expressing human pulmonary cells Beas2B as well as human primary nasal epithelial cells. Altogether, these results validate our cell-based functional assay and the interest of screening libraries of different origins to identify inhibitors of SARS-CoV-2 for drug repurposing or development.

中文翻译：

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用于监测 SARS-CoV-2 复制和识别抑制剂的生物发光 3CLPro 活性测定

我们针对病毒的治疗手段非常有限，当前 SARS-CoV-2 的大流行凸显了对针对新出现的冠状病毒的有效抗病毒药物的迫切需求。允许在高通量实验环境中精确定量病毒复制的细胞测定对于筛选化学文库和选择最佳抗病毒化学结构至关重要。为了开发 SARS-CoV-2 感染的报告系统，我们生成了表达萤火虫荧光素酶的细胞系，该细胞系通过冠状病毒的病毒蛋白酶 3CL ^Pro的共有切割位点保持非活性形式，以便发光生物传感器在 3CL 上打开^Pro表达或 SARS-CoV-2 感染。该细胞测定用于筛选 492 种化合物的代谢导向库，以确定冠状病毒的代谢脆弱性，从而开发创新的治疗策略。与最近的报道一致，发现嘧啶生物合成抑制剂可以阻止 SARS-CoV-2 复制。在热门产品中，我们还发现了 NADPH 氧化酶 (NOX) 抑制剂 Setanaxib。使用表达 ACE2 的人肺细胞 Beas2B 以及人原代鼻上皮细胞进一步证实了 Setanaxib 的抗 SARS-CoV-2 活性。总而言之，这些结果验证了我们基于细胞的功能测定以及筛选不同来源的文库以确定 SARS-CoV-2 抑制剂以用于药物重新利用或开发的兴趣。