Construction and characterization of Genotype-3 hepatitis C virus replicon revealed critical genotype-3-specific polymorphism for drug resistance and viral fitness
Construction and characterization of Genotype-3 hepatitis C virus replicon revealed critical genotype-3-specific polymorphism for drug resistance and viral fitness
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基因型 3 丙型肝炎病毒复制子的构建和表征揭示了耐药性和病毒适应性的关键基因型 3 特异性多态性。
DOI：
10.1016/j.antiviral.2019.104612
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发表时间：
2019-11-01
影响因子：
7.6
通讯作者：
Zhong, Jin
中科院分区：
文献类型：
--
作者：
Guo, Mingzhe;Lu, Jie;Zhong, Jin
丙型肝炎病毒（HCV）是慢性肝炎的主要病原体，是一种正链RNA病毒，由于其易于出错的RNA依赖性RNA聚合酶而具有高度的遗传多样性。直接作用的抗病毒药物（DAA）的发展大大改善了慢性丙型肝炎患者的治疗结果。然而，HCV基因组中天然存在的耐药相关变体（RAV）或耐药相关置换（RAS）的发生可能对基于DAA的治疗的长期成功构成挑战。基因3型HCV是最难用DAA治疗的基因型，但其潜在的分子机制仍有待探索。在这里，我们开发了一种新的基因型-3a亚基因组复制子PR 87 A7通过筛选从患者血清RNA扩增的HCV cDNA池。PR 87 A7复制子对抗NS 3 DAA表现出较强的抗性，这主要归因于NS 3中基因型3特异性多态性168 Q。将NS 3 168 Q引入基因型2a JFH 1菌株中，使其对抗NS 3 DAA具有抗性，同时大大减少了病毒复制，但这种适应性缺陷可以通过额外的基因型3特异性多态性来挽救。总之，我们通过功能筛选方法开发了一种新的基因型-3a亚基因组复制子，并揭示了基因型-3特异性氨基酸残基，其赋予抗NS 3 DAA抗性，同时保留病毒适应性。
Hepatitis C virus (HCV), a major causative agent of chronic hepatitis, is a positive-stranded RNA virus and has a high degree of genetic diversity due to its error-prone RNA-dependent RNA polymerase. Development of directacting antiviral agents (DAAs) has greatly improved the therapeutic outcome of chronic hepatitis C patients. However, naturally existing resistance-associated variants (RAVs) or occurrence of resistance-associated substitutions (RASs) in the HCV genome may impose a challenge to the long-term success of the DAA-based therapies. Genotype-3 HCV is the most difficult genotype to treat by DAAs, but the underlying molecular mechanisms remain to be explored. Here we developed a novel genotype-3a subgenomic replicon PR87A7 by screening a HCV cDNA pool amplified from a patient serum RNA. PR87A7 replicon displayed strong resistance to anti-NS3 DAAs, mainly owing to a genotype-3-specific polymorphism 168Q in NS3. Introduction of NS3 168Q into a genotype-2a JFH1 strain rendered resistance to anti-NS3 DAAs while greatly diminished the viral replication, and yet this fitness defect can be rescued by additional genotype-3-specific polymorphism. In conclusion, we developed a novel genotype-3a subgenomic replicon by a functional screening approach, and revealed genotype-3-specfic amino acid residues that confer resistance to anti-NS3 DAAs while retaining viral fitness.