Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland.
School of Life Sciences, Faculty of Medicine and Health Sciences, The University of Nottingham, Nottingham, United Kingdom; Wolfson Centre for Global Virus Research, The University of Nottingham, Nottingham, United Kingdom; National Institute for Health Research Nottingham Biomedical Research Centre, Nottingham University Hospitals National Health Service Trust, Nottingham, United Kingdom.
Gastroenterology. 2022 Feb;162(2):562-574. doi: 10.1053/j.gastro.2021.10.005. Epub 2021 Oct 13.
BACKGROUND & AIMS: Development of a prophylactic hepatitis C virus (HCV) vaccine will require accurate and reproducible measurement of neutralizing breadth of vaccine-induced antibodies. Currently available HCV panels may not adequately represent the genetic and antigenic diversity of circulating HCV strains, and the lack of standardization of these panels makes it difficult to compare neutralization results obtained in different studies. Here, we describe the selection and validation of a genetically and antigenically diverse reference panel of 15 HCV pseudoparticles (HCVpps) for neutralization assays.
We chose 75 envelope (E1E2) clones to maximize representation of natural polymorphisms observed in circulating HCV isolates, and 65 of these clones generated functional HCVpps. Neutralization sensitivity of these HCVpps varied widely. HCVpps clustered into 15 distinct groups based on patterns of relative sensitivity to 7 broadly neutralizing monoclonal antibodies. We used these data to select a final panel of 15 antigenically representative HCVpps.
Both the 65 and 15 HCVpp panels span 4 tiers of neutralization sensitivity, and neutralizing breadth measurements for 7 broadly neutralizing monoclonal antibodies were nearly equivalent using either panel. Differences in neutralization sensitivity between HCVpps were independent of genetic distances between E1E2 clones.
Neutralizing breadth of HCV antibodies should be defined using viruses spanning multiple tiers of neutralization sensitivity rather than panels selected solely for genetic diversity. We propose that this multitier reference panel could be adopted as a standard for the measurement of neutralizing antibody potency and breadth, facilitating meaningful comparisons of neutralization results from vaccine studies in different laboratories.
开发预防性丙型肝炎病毒（HCV）疫苗需要准确且可重复地测量疫苗诱导抗体的中和广度。目前可用的 HCV 检测面板可能无法充分代表循环 HCV 株的遗传和抗原多样性，并且这些检测面板缺乏标准化，使得难以比较不同研究中获得的中和结果。在这里，我们描述了一种遗传和抗原多样性的参考 HCV 假病毒（HCVpp）面板的选择和验证，用于中和测定。
我们选择了 75 个包膜（E1E2）克隆，以最大限度地代表循环 HCV 分离物中观察到的自然多态性，并生成了其中 65 个克隆的功能性 HCVpp。这些 HCVpp 的中和敏感性差异很大。根据对 7 种广泛中和单克隆抗体的相对敏感性模式，HCVpp 聚类为 15 个不同的组。我们使用这些数据选择了最终的 15 个具有代表性的抗原 HCVpp 面板。
65 个和 15 个 HCVpp 面板都跨越了 4 个中和敏感性级别，并且使用任一面板测量 7 种广泛中和单克隆抗体的中和广度几乎是等效的。HCVpp 之间的中和敏感性差异与 E1E2 克隆之间的遗传距离无关。
应该使用跨越多个中和敏感性级别的病毒来定义 HCV 抗体的中和广度，而不是仅根据遗传多样性选择面板。我们建议可以采用这种多梯级参考面板作为测量中和抗体效力和广度的标准，从而促进不同实验室的疫苗研究中中和结果的有意义比较。
