Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre and Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark.
Hepatology. 2023 Aug 1;78(2):621-636. doi: 10.1097/HEP.0000000000000353. Epub 2023 Apr 3.
The high HCV infection cure rates achieved with direct-acting antiviral (DAA) treatments could be compromised in the future by the emergence of antiviral resistance. Thus, it is essential to understand the viral determinants that influence DAA resistance, which is most prevalent in genotype 3. We aimed at studying how resistance to protease-, NS5A-, and NS5B-inhibitors influences the activities of glecaprevir/pibrentasvir, sofosbuvir/velpatasvir, and sofosbuvir/velpatasvir/voxilaprevir in cell culture, and how the HCV genome adapts to selective pressure by successive rounds of treatment failure.
A previously developed in vivo infectious cDNA clone of strain S52 (genotype 3a) was adapted to efficiently replicate and propagate in human hepatoma cells (Huh7.5) using 31 adaptive substitutions. DAA escape experiments resulted in the selection of S52 variants with decreased drug susceptibility (resistance), which was linked to the emergence of known resistance-associated substitutions (RASs). NS5A-inhibitor resistance was sufficient to promote treatment failure with double-DAA but not triple-DAA regimens. Enhanced viral fitness associated with the selection of sofosbuvir resistance accelerated escape from DAAs. After serial DAA treatment failure, HCV genetic evolution led to a complex genome-wide network of substitutions, some of which coevolved with known RASs.
Baseline NS5A-RAS can compromise the efficacy of double-DAA pangenotypic regimens for HCV genotype 3, and enhanced viral fitness can accelerate treatment failure. Persistence of RASs after successive treatment failure is facilitated by the remarkable evolutionary capacity and plasticity of the HCV genome. Proof-of-concept for the potential development of multi-DAA resistance is shown.
直接作用抗病毒药物（DAA）治疗实现的高 HCV 感染治愈率，可能因抗病毒耐药性的出现而受到影响。因此，了解影响 DAA 耐药性的病毒决定因素至关重要，而这种耐药性在基因型 3 中最为常见。我们旨在研究蛋白酶、NS5A 和 NS5B 抑制剂耐药性如何影响 glecaprevir/pibrentasvir、索非布韦/velpatasvir 和索非布韦/velpatasvir/voxilaprevir 在细胞培养中的活性，以及 HCV 基因组如何通过连续轮次的治疗失败来适应选择性压力。
我们对 S52 株（基因型 3a）的一种先前开发的体内传染性 cDNA 克隆进行了改造，使其能够在人肝癌细胞（Huh7.5）中高效复制和繁殖，共引入了 31 个适应性替换。DAA 逃逸实验导致药物敏感性降低（耐药性）的 S52 变体的选择，这与已知耐药相关取代（RAS）的出现有关。NS5A 抑制剂耐药足以促进双重-DAA 但不能促进三重-DAA 方案的治疗失败。与选择索非布韦耐药相关的增强病毒适应性加速了对 DAA 的逃逸。经过连续 DAA 治疗失败后，HCV 遗传进化导致了一个复杂的全基因组替代网络，其中一些与已知的 RAS 共同进化。
基线 NS5A-RAS 可降低 HCV 基因型 3 双-DAA 泛基因型方案的疗效，增强的病毒适应性可加速治疗失败。在连续治疗失败后，RAS 的持续存在，是由 HCV 基因组的显著进化能力和可塑性所促成的。证明了多-DAA 耐药性的潜在发展的概念验证。
