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: 9478874
• 负责人: Justin Richard Bailey
• 金额: $ 71.99万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-05-01 至 2022-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9478874
• 关键词: Amino Acids; Animal Model; Antibodies; Antibody Binding Sites; Antiviral Therapy; Binding; Binding Sites; Biochemical; CD81 gene; Caring; Complex; Crystallization; Data; Development; Dimensions; Disease; Distant; Epidemiology; Epitopes; Future; Genetic; Genetic Polymorphism; Goals; HIV; Hepatitis C; Hepatitis C Antibodies; Hepatitis C Vaccine; Hepatitis C virus; Human; Immunologics; In Vitro; Individual; Infection; Infection prevention; Investigation; Measures; Modification; Molecular; Monoclonal Antibodies; Proteins; Reagent; Role; Sequence Analysis; Somatic Mutation; Structure; Therapeutic Agents; United States; Vaccine Antigen; Vaccine Design; Vaccines; Variant; Virus; Work; anti-hepatitis C; design; effective therapy; env Gene Products; glycosylation; high risk; neutralizing antibody; pandemic disease; protein folding; vaccine development; vaccine trial; virology; virus envelope

Project Summary A vaccine against Hepatitis C virus (HCV) is urgently needed. HCV infects over 170 million people worldwide and kills more people in the United States annually than HIV. While direct-acting antiviral (DAA) therapy has revolutionized HCV care, control of the HCV pandemic remains challenging due frequent reinfection in high-risk individuals and a high proportion of asymptomatic carriers who continue to infect others. Approximately 30% of individuals who become infected with HCV spontaneously clear the infection, and we have previously shown that this spontaneous clearance of HCV is associated with early development of broadly neutralizing antibodies (bNAbs) against the virus. BNAbs are also protective against HCV infection in multiple animal models. Unfortunately, to date, vaccines against HCV have not induced adequate titers of protective bNAbs. Our inability to induce potent bNAbs is in part due to our poor understanding of the molecular and structural interactions between bNAbs and HCV envelope proteins (E1 and E2). Our preliminary work indicates that envelope sequence polymorphisms distant from bNAb binding sites have a strong, unexpected influence on neutralization sensitivity. These data and rapidly emerging work in HIV indicate that these crucial bNAb-envelope interactions need to be understood in a three dimensional (structural) context. We hypothesize that molecular and structural analysis of bNAb-E2 interactions will allow us to rationally design stable HCV envelope proteins with optimized bNAb epitopes that are ideal for structural and vaccine studies as well as bNAbs with enhanced neutralizing potency and breadth, better defining the ideal antibodies that should be induced by a vaccine. We have characterized a diverse panel of unique HCV envelope proteins and isolated some of the most broadly neutralizing anti-HCV monoclonal antibodies described to date. In Aim 1, we will functionally and molecularly characterize interactions between this panel of diverse, naturally occurring HCV envelope variants and the panel of bNAbs, which will allow us to identify amino acid determinants of neutralization sensitivity of E2 as well as somatic mutations conferring neutralizing potency and breadth to bNAbs. In Aim 2, we will define biochemical and molecular factors influencing stability and native folding of HCV envelope proteins. We will clone more than 100 distinct natural HCV E2 variants and identify polymorphisms associated with stable in vitro E2 expression. In Aim 3, we will determine structural correlates of broad and potent neutralization of HCV. We will crystallize HCV E2 in complex with bNAbs of varying breadth and potency. We will use the data acquired through these three aims to design stable E2 variants with optimized bNAb epitopes that will be ideal reagents for future structure analyses and vaccine studies. In addition, we will design bNAbs with enhanced neutralizing potency and breadth that will define the ideal antibodies that could be induced by a vaccine and may also be useful therapeutic agents. Through these investigations, we will advance rational design of an HCV vaccine.

项目摘要 迫切需要针对丙型肝炎病毒（HCV）的疫苗。 HCV在全球感染了超过1.7亿人 并杀死美国比艾滋病毒更多的人。直接作用抗病毒（DAA）疗法具有 革命性的HCV护理，HCV大流行的控制仍然具有挑战性 继续感染他人的个人和高比例的无症状载体。大约30％ 被HCV感染的人会自发清除感染，我们以前已显示 HCV的这种自发清除与广泛中和抗体的早期发展有关 （bnabs）针对病毒。在多种动物模型中，BNAB也可以防止HCV感染。 不幸的是，迄今为止，针对HCV的疫苗还没有引起足够的保护性BNAB滴度。我们的无能 诱导有效的bnabs部分是由于我们对分子和结构相互作用的不良理解 在BNAB和HCV包膜蛋白（E1和E2）之间。我们的初步工作表明信封 远离BNAB结合位点的序列多态性对中和具有强大的意外影响 灵敏度。这些数据和HIV中快速新兴的工作表明这些关键的BNAB-Envelope相互作用 需要在三维（结构）环境中理解。我们假设该分子和结构 BNAB-E2相互作用的分析将使我们能够合理设计稳定的HCV包膜蛋白，并具有优化 BNAB表位是结构性和疫苗研究的理想选择，以及具有增强中和的BNAB 效力和广度，更好地定义应由疫苗诱导的理想抗体。 我们已经描述了一系列独特的HCV信封蛋白的各种面板，并隔离了一些最广泛的蛋白质 迄今为止描述的中和抗HCV单克隆抗体。在AIM 1中，我们将在功能和分子上 表征了这个多种多样的，自然发生的HCV信封变体与面板之间的相互作用 bnabs，这将使我们能够鉴定E2中和敏感性的氨基酸决定因素 体细胞突变赋予bnabs中和宽度的中和宽度。在AIM 2中，我们将定义生化 以及影响HCV包膜蛋白的稳定性和天然折叠的分子因子。我们将克隆比 100个不同的天然HCV E2变体，并鉴定与稳定的体外E2表达相关的多态性。 在AIM 3中，我们将确定HCV的广泛和有效中和的结构相关性。我们将结晶 HCV E2具有不同的宽度和效力的复杂性。我们将使用通过这些获取的数据 三个目的是设计稳定的E2变体，具有优化的BNAB表位，这将是未来的理想试剂 结构分析和疫苗研究。此外，我们将设计具有增强中和效力的BNABS 和宽度将定义可以由疫苗诱导的理想抗体，并且也可能有用 治疗剂。通过这些研究，我们将推进HCV疫苗的合理设计。