Molecular and structural characterization of broadly neutralizing anti-HCV antibodies

广泛中和抗 HCV 抗体的分子和结构表征

基本信息

批准号：
10657917
负责人：
Justin Richard Bailey
金额：
$ 82.09万
依托单位：
JOHNS HOPKINS UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-02-15 至 2028-01-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10657917
关键词：
Affinity Animal Model Antibodies Antibody Binding Sites Antibody Response Antiviral Agents Award B-Cell Antigen Receptor B-Lymphocytes B-cell receptor repertoire sequencing Binding Cell Separation Chronic Complex Country Cryoelectron Microscopy Development Disease Disease Outcome Epitopes Genetic Glycoproteins Goals HIV Hepatitis C Hepatitis C Antibodies Hepatitis C Incidence Hepatitis C Vaccine Hepatitis C virus Human Immune response Immunological Models In Vitro Individual Infection Length Measures Methods Molecular Monoclonal Antibodies Persons Phase Plasma Process Proteins Public Health Resolution Somatic Mutation Sorting Structure Surveys T cell response T-Lymphocyte Techniques Time Vaccine Antigen Vaccine Design Vaccines Variant Viral Viremia Virus Virus Diseases Work X-Ray Crystallography chronic infection design effective therapy env Gene Products improved neutralizing antibody rational design vaccine candidate vaccine development virus envelope

项目摘要

Summary More than 70 million people worldwide are infected with hepatitis C virus (HCV), and development of a vaccine for HCV is essential for disease eradication. Although direct-acting antivirals are highly effective for treatment, the majority of countries surveyed are not on track to reach the WHO goal of eliminating HCV as a public health problem by 2030, with most countries seeing rising incidence of HCV. Fortunately, there is strong evidence that vaccine-induction of high titers of broadly neutralizing antibodies (bNAbs; antibodies capable of neutralizing diverse HCV variants) could provide protection against human HCV infection. However, we are unable to stimulate bNAbs against HCV with a vaccine because we have not defined the full spectrum of anti-HCV antibodies that are critical for neutralizing breadth or characterized the HCV envelope glycoprotein (E1 and E2) genetic and structural features that favor bNAb selection and maturation. The overarching goal of this proposal is to isolate a large and representative set of E1E2-specific bNAbs, bNAb unmutated ancestors, and bNAb intermediates from Elite Neutralizers (EN), individuals with broadly neutralizing plasma and spontaneous clearance of HCV infection. In Aim 1, we will isolate monoclonal antibodies (mAbs) from E1E2-specific B cells isolated from EN and from controls with chronic, persistent infection (CP). We will infer unmutated germline bNAb ancestors and use B cell receptor-sequencing of longitudinal E1E2-specific B cells to identify bNAb genetic intermediates. We will compare neutralizing breadth, potency, epitopes, and genetic features for EN vs. CP mAbs. In Aim 2, we will use X-ray crystallography or cryo-EM techniques to compare structures of EN bNAbs or CP mAbs in complex with soluble E2 or E1E2 heterodimers. By comparing mAb-E1E2 interactions among CP mAbs, bNAb unmutated ancestors, bNAb intermediates, and mature bNAbs, we will define structural and genetic features of E1E2 necessary for the development of neutralizing breadth. Together, these studies will identify a large, representative set of bNAbs associated with spontaneous clearance of HCV, defining key epitope residues and structural features in E1E2 that could be stabilized to optimize vaccine antigens. These studies will inform structure-based design efforts to improve E1E2-based vaccine candidates, which is an urgent challenge with global public health implications.

概括全球有超过 7000 万人感染丙型肝炎病毒 (HCV)，疫苗的开发 HCV 对于根除疾病至关重要。虽然直接作用的抗病毒药物治疗非常有效，大多数接受调查的国家都没有走上实现世卫组织消除丙型肝炎作为公共卫生的目标的轨道到 2030 年，大多数国家的 HCV 发病率都会上升。幸运的是，有强有力的证据表明疫苗诱导高滴度的广泛中和抗体（bNAb；能够中和不同的 HCV 变种）可以提供针对人类 HCV 感染的保护。然而，我们无法用疫苗刺激 bNAbs 对抗 HCV，因为我们还没有定义全谱的抗 HCV 对于中和广度或表征 HCV 包膜糖蛋白至关重要的抗体（E1 和 E2）有利于 bNAb 选择和成熟的遗传和结构特征。本提案的总体目标的目的是分离大量具有代表性的 E1E2 特异性 bNAb、bNAb 未突变祖先和 bNAb 来自精英中和者（EN）的中间体，具有广泛中和血浆和自发性的个体清除HCV感染。在目标 1 中，我们将从 E1E2 特异性 B 细胞中分离单克隆抗体 (mAb) 从 EN 和患有慢性持续性感染 (CP) 的对照中分离出来。我们将推断未突变的种系 bNAb 祖先并使用纵向 E1E2 特异性 B 细胞的 B 细胞受体测序来识别 bNAb 遗传中间体。我们将比较 EN 与 CP 的中和广度、效力、表位和遗传特征单克隆抗体。在目标 2 中，我们将使用 X 射线晶体学或冷冻电镜技术来比较 EN bNAb 或 CP mAb 与可溶性 E2 或 E1E2 异二聚体形成复合物。通过比较 CP 之间的 mAb-E1E2 相互作用 mAb、bNAb 未突变祖先、bNAb 中间体和成熟 bNAb，我们将定义结构和遗传 E1E2 的特征对于中和广度的发展是必需的。这些研究将共同确定与 HCV 自发清除相关的大量具有代表性的 bNAb，定义了关键表位残基以及 E1E2 中可以稳定以优化疫苗抗原的结构特征。这些研究将告知基于结构的设计工作，以改进基于 E1E2 的候选疫苗，这是一个紧迫的挑战全球公共卫生影响。