Liver Unit, Liver Disease Laboratory-Viral Hepatitis, Internal Medicine Department, Vall d'Hebron Institut Recerca (VHIR)-Hospital Universitari Vall d'Hebron (HUVH), Barcelona, Spain.
Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd) del Instituto de Salud Carlos III, Madrid, Spain.
PLoS One. 2018 Oct 3;13(10):e0204877. doi: 10.1371/journal.pone.0204877. eCollection 2018.
RNA viruses replicate with a template-copying fidelity, which lies close to an extinction threshold. Increases of mutation rate by nucleotide analogues can drive viruses towards extinction. This transition is the basis of an antiviral strategy termed lethal mutagenesis. We have introduced a new diversity index, the rare haplotype load (RHL), to describe NS5B (polymerase) mutant spectra of hepatitis C virus (HCV) populations passaged in absence or presence of the mutagenic agents favipiravir or ribavirin. The increase in RHL is more prominent in mutant spectra whose expansions were due to nucleotide analogues than to multiple passages in absence of mutagens. Statistical tests for paired mutagenized versus non-mutagenized samples with 14 diversity indices show that RHL provides consistently the highest standardized effect of mutagenic treatment difference for ribavirin and favipiravir. The results indicate that the enrichment of viral quasispecies in very low frequency minority genomes can serve as a robust marker for lethal mutagenesis. The diagnostic value of RHL from deep sequencing data is relevant to experimental studies on enhanced mutagenesis of viruses, and to pharmacological evaluations of inhibitors suspected to have a mutagenic activity.
RNA 病毒以接近灭绝阈值的模板复制保真度进行复制。核苷酸类似物的突变率增加可促使病毒走向灭绝。这种转变是一种称为致死诱变的抗病毒策略的基础。我们引入了一个新的多样性指数，即稀有单倍型负荷（RHL），用于描述在不存在或存在诱变剂法匹拉韦或利巴韦林的情况下传代的丙型肝炎病毒（HCV）群体中 NS5B（聚合酶）突变体谱。与未诱变样本相比，由于核苷酸类似物而扩展的突变体谱中 RHL 的增加更为明显，而不是在没有诱变剂的情况下多次传代。对于 14 种多样性指数的配对诱变与非诱变样本的统计检验表明，RHL 为利巴韦林和法匹拉韦的诱变处理差异提供了始终最高的标准化效应。结果表明，病毒准种在非常低频率的少数基因组中的富集可用作致死诱变的稳健标志物。来自深度测序数据的 RHL 的诊断价值与增强病毒诱变的实验研究以及对疑似具有诱变活性的抑制剂的药理学评估相关。
