Molnupiravir,N-羟胞苷(NHC)的口服前药,先前已证明对多种RNA病毒具有广泛的体外抗病毒活性,并已显示出对抗性发展的高障碍。这里,我们介绍了NHC对近期SARS-CoV-2变种的抗病毒活性和抗性选择研究的结果,以更好地了解病毒对NHC的抗性潜力.NHC对SARS-CoV-2变体omicron(BA.1,BA.1.1,BA.2,BA4,BA.4.6,BA.5,BQ.1.1,XBB.1和XBB.1.5)的活性,阿尔法(B.1.1.7),beta(B.1.351),gamma(P.1),三角洲(B.1.617.2),lambda(C.37),使用细胞病变效应测定在VeroE6细胞中评估mu(B.1.621)。通过在NHC或3C样蛋白酶抑制剂(MRK-A)存在下在VeroE6细胞中传代SARS-CoV-2(WA1)进行抗性选择研究。将细胞病变效应评分≥2的培养物上清液重新传代,并估算IC50值。对在每次传代时分离的病毒RNA进行全基因组深度测序。NHC对所评估的所有SARS-CoV-2变体表现出相似的效力。30次传代后,未观察到SARS-CoV-2对NHC的表型或基因型抗性的证据。在NHC培养物中观察到核苷酸变化的随机模式,与药物的作用机制一致。相比之下,通过在3C样蛋白酶中选择T21I取代,在所有三种MRK-A对照培养物中容易地选择抗性。总之,molnupiravir在所有主要的SARS-CoV-2变体中保持抗病毒活性。此外,没有观察到病毒对NHC的抗性的证据,支持以前的报道,即NHC对发展抗药性有很高的障碍。
Molnupiravir, an oral prodrug of N-hydroxycytidine (NHC), previously demonstrated broad in vitro antiviral activity against multiple RNA viruses and has shown a high barrier to the development of resistance. Here, we present the antiviral activity of NHC against recent SARS-CoV-2 variants and the results of resistance selection studies to better understand the potential for viral resistance to NHC. NHC activity against SARS-CoV-2 variants omicron (BA.1, BA.1.1, BA.2, BA.4, BA.4.6, BA.5, BQ.1.1, XBB.1, and XBB.1.5), alpha (B.1.1.7), beta (B.1.351), gamma (P.1), delta (B.1.617.2), lambda (C.37), and mu (B.1.621) was evaluated in Vero E6 cells using cytopathic effect assays. Resistance selection studies were performed by passaging SARS-CoV-2 (WA1) in the presence of NHC or a 3C-like protease inhibitor (MRK-A) in Vero E6 cells. Supernatants from cultures exhibiting a cytopathic effect score of ≥2 were re-passaged, and IC50 values were estimated. Whole-genome deep sequencing was performed on viral RNA isolated at each passage. NHC demonstrated similar potency against all SARS-CoV-2 variants evaluated. No evidence of SARS-CoV-2 phenotypic or genotypic resistance to NHC was observed following 30 passages. A random pattern of nucleotide changes was observed in NHC cultures, consistent with the drug\'s mechanism of action. In contrast, resistance was readily selected in all three MRK-A control cultures with the selection of a T21I substitution in the 3C-like protease. In conclusion, molnupiravir maintains antiviral activity across all major SARS-CoV-2 variants. Furthermore, no evidence of viral resistance to NHC was observed, supporting previous reports that NHC has a high barrier to developing resistance.