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

• 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
• 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

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 全世界有超过7000万人感染了丙型肝炎病毒（HCV），并开发了疫苗 因为HCV对于消除疾病至关重要。尽管直接作用抗病毒药对治疗非常有效，但 接受调查的大多数国家都没有实现WHO的目标，即消除HCV作为公共卫生 到2030年的问题，大多数国家的发病率上升。幸运的是，有充分的证据表明 广泛中和抗体的高滴度的疫苗诱导（BNABS；能够中和的抗体 不同的HCV变体可以提供防止人类HCV感染的保护。但是，我们无法 用疫苗刺激针对HCV的BNAB，因为我们尚未定义全部抗HCV 对于中和宽度或表征HCV包膜糖蛋白（E1和E2）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。该提议的总体目标 是要隔离一组大而代表性的E1E2特异性bnabs，bnab未分离的祖先和bnab 来自精英中源（EN）的中间体，具有广泛中和血浆和自发的个体 HCV感染的清除。在AIM 1中，我们将从E1E2特异性B细胞中分离单克隆抗体（mAb） 从EN和具有慢性，持续感染（CP）的对照中分离出来。我们将推断未成熟的种系BNAB 祖先并使用纵向E1E2特异性B细胞的B细胞受体测序鉴定BNAB遗传 中间人。我们将比较EN与CP的中和广度，效能，表位和遗传特征 mabs。在AIM 2中，我们将使用X射线晶体学或冷冻EM技术来比较EN BNAB的结构或 与可溶性E2或E1E2异二聚体复合物的CP mAb。通过比较CP之间的MAB-E1E2相互作用 mAb，bnab未分离的祖先，bnab中间体和成熟的bnab，我们将定义结构和遗传 E1E2的特征是开发中和广度所必需的。这些研究将共同​​确定 与HCV自发清除相关的大型代表性BNAB，定义了关键表位残基 E1E2中的结构特征可以稳定以优化疫苗抗原。这些研究将告知 基于结构的设计工作以改善基于E1E2的疫苗候选者，这是一个紧迫的挑战 全球公共卫生的影响。