Technical University of Denmark, National Veterinary Institute (DTU Vet), Kemitorvet, Lyngby, Denmark.
Statens Serum Institut, Copenhagen, Denmark.
Antimicrob Agents Chemother. 2018 Aug 27;62(9). doi: 10.1128/AAC.00380-18. Print 2018 Sep.
Flaviviruses constitute an increasing source of public health concern, with growing numbers of pathogens causing disease and geographic spread to temperate climates. Despite a large body of evidence supporting mutagenesis as a conceivable antiviral strategy, there are currently no data on the sensitivity to increased mutagenesis for Zika virus (ZIKV) and Usutu virus (USUV), two emerging flaviviral threats. In this study, we demonstrate that both viruses are sensitive to three ribonucleosides, favipiravir, ribavirin, and 5-fluorouracil, that have shown mutagenic activity against other RNA viruses while remaining unaffected by a mutagenic deoxyribonucleoside. Serial cell culture passages of ZIKV in the presence of these compounds resulted in the rapid extinction of infectivity, suggesting elevated sensitivity to mutagenesis. USUV extinction was achieved when a 10-fold dilution was applied between every passage, but not in experiments involving undiluted virus, indicating an overall lower susceptibility than ZIKV. Although the two viruses are inhibited by the same three drugs, ZIKV is relatively more susceptive to serial passage in the presence of purine analogues (favipiravir and ribavirin), while USUV replication is suppressed more efficiently by 5-fluorouracil. These differences in sensitivity typically correlate with the increases in the mutation frequencies observed in each nucleoside treatment. These results are relevant to the development of efficient therapies based on lethal mutagenesis and support the rational selection of different mutagenic nucleosides for each pathogen. We will discuss the implications of these results to the fidelity of flavivirus replication and the design of antiviral therapies based on lethal mutagenesis.
黄病毒属是日益引起公众健康关注的病原体，越来越多的病原体导致疾病，并在温带地区传播。尽管有大量证据支持诱变是一种可行的抗病毒策略，但目前尚无关于寨卡病毒（ZIKV）和乌苏图病毒（USUV）对增加诱变敏感性的数据，这两种新兴的黄病毒威胁。在这项研究中，我们证明这两种病毒对三种核糖核苷，即法匹拉韦、利巴韦林和 5-氟尿嘧啶敏感，这些核苷对其他 RNA 病毒具有诱变活性，而对诱变脱氧核糖核苷没有影响。在这些化合物的存在下，对 ZIKV 进行连续细胞培养传代会导致感染性迅速消失，这表明对诱变的敏感性增加。当在每次传代之间进行 10 倍稀释时，USUV 可以被消灭，但在不稀释病毒的实验中，USUV 没有被消灭，这表明其整体敏感性低于 ZIKV。尽管这两种病毒都被三种药物抑制，但 ZIKV 在嘌呤类似物（法匹拉韦和利巴韦林）存在下的连续传代中相对更敏感，而 USUV 的复制则更有效地被 5-氟尿嘧啶抑制。这些敏感性差异通常与每种核苷处理中观察到的突变频率增加相关。这些结果与基于致死性诱变开发有效疗法相关，并支持针对每种病原体选择不同诱变核苷的合理选择。我们将讨论这些结果对黄病毒复制保真度和基于致死性诱变的抗病毒疗法设计的影响。
