SARS-CoV-2 NSP14 inhibitor exhibits potent antiviral activity and reverses NSP14-driven host modulation

The emergence of SARS-CoV-2 variants and drug-resistant mutants underscores the urgent need for novel antiviral therapeutics. SARS-CoV-2 NSP14, an N7-guanosine methyltransferase, plays a critical role in viral RNA capping, enabling viral replication and immune evasion. While NSP14 has emerged as a promising drug target, its role in host-virus crosstalk and the cellular consequences of NSP14 inhibition remain poorly understood. Here, we present the identification and characterization of C10, a highly potent and selective first-in-class non-nucleoside inhibitor of the NSP14 S-adenosylmethionine (SAM)-binding pocket. C10 demonstrates robust antiviral activity against SARS-CoV-2, including its variants, with EC50 values ranging from 64.03 to 301.9 nM, comparable to the FDA-approved drug remdesivir in our cell-based assays. C10 also exhibits broad-spectrum activity against other betacoronaviruses and directly suppresses SARS-CoV-2 genomic replication. C10 specifically reversed NSP14-mediated alterations in host transcriptome and restored host cell cycle progression disrupted by NSP14. The antiviral efficacy of C10 was further validated in a transgenic mouse model of SARS-CoV-2 infection. Our findings highlight C10 as a promising candidate for the development of effective treatments against SARS-CoV-2 and its emerging variants. This study also uncovers a novel mechanism of NSP14 in SARS-CoV-2 pathogenesis and its therapeutic potential, providing insights that may extend to other viral capping methyltransferases. NGS seqence of NSP14 in SARS-COV-2 resistance mutants

新型冠状病毒（SARS-CoV-2）变异株与耐药突变株的出现，凸显了开发新型抗病毒治疗药物的迫切需求。SARS-CoV-2非结构蛋白14（NSP14）是一种N7-鸟苷甲基转移酶（N7-guanosine methyltransferase），在病毒RNA加帽过程中发挥关键作用，介导病毒复制与免疫逃逸。尽管NSP14已成为极具潜力的药物靶点，但其在宿主-病毒互作中的功能，以及抑制NSP14所引发的细胞效应仍有待深入阐明。本研究鉴定并表征了C10——一种强效且高选择性的同类首创靶向NSP14 S-腺苷甲硫氨酸（SAM）结合口袋的非核苷类抑制剂。C10对新型冠状病毒（含其变异株）展现出强劲的抗病毒活性，半最大效应浓度（EC50）值范围为64.03至301.9 nM，在本研究的细胞实验中，其活性可与美国食品药品监督管理局（FDA）批准的药物瑞德西韦相媲美。C10同时对其他β冠状病毒表现出广谱抗病毒活性，并可直接抑制新型冠状病毒的基因组复制。C10能够特异性逆转NSP14介导的宿主转录组改变，并修复NSP14所破坏的宿主细胞周期进程。C10的抗病毒功效在新型冠状病毒感染的转基因小鼠模型中得到了进一步验证。本研究结果表明，C10是开发针对新型冠状病毒及其新兴变异株的有效治疗药物的极具潜力的候选化合物。此外，本研究还揭示了NSP14在新型冠状病毒致病机制中的全新作用模式及其治疗潜力，相关发现或可为其他病毒加帽相关甲基转移酶的研究提供参考。本数据集包含新型冠状病毒耐药突变株中NSP14的下一代测序（NGS）序列。