Probing the antibody response to HCV to facilitate rational immunogen design

描述（由申请人提供）：全世界约有1.7亿人感染丙型肝炎病毒（HCV），其中许多人将继续发展疾病，主要是肝硬化和肝癌。需要疫苗来帮助限制疾病的传播。迄今为止开发的最有效的疫苗引起中和抗体（NAb）。在开发一种能使NAb与HCV结合的成分的过程中，至少有两个主要的障碍。首先是缺乏常规的中和试验，因为不能在体外培养HCV。这个障碍最近已经至少部分地被用于培养HCV的系统的开发所拆除，尽管目前具有某些限制。第二个障碍是在受感染的供体中发现的HCV的巨大序列变异，这表明疫苗应该引发有效对抗各种不同病毒的NAb，即疫苗应该引发广泛中和抗体。我们提出了一个计划，以调查必要的条件，以诱导一个强大的中和抗体反应，对多种HCV分离株，并利用所获得的知识来设计一个NAB诱导的HCV疫苗的组成部分。我们将系统地剖析自然感染中NAb对HCV的应答，并分离出最有效和最广泛的抗HCV中和分离株的mAb（目的1）。这些原型单克隆抗体将帮助我们鉴定HCV上的中和表位，我们将在分子水平上探索这些表位与NAb之间的相互作用（目的2）。我们将从这些分子研究中获得的知识应用于免疫原的设计，以在动物中产生NAb应答（目的3）。将在小动物模型中测试来自用新型免疫原免疫的动物的原型广泛中和mAb和Ab（目的4）。 公共卫生相关性：丙型肝炎病毒感染是世界范围内的主要健康问题，迫切需要疫苗来保护高危人群。我们建议开发针对HCV的抗体诱导疫苗候选物。我们工作的一个关键特征是基于对抗这种病毒用来逃避抗体的一些技巧来合理设计候选疫苗。

DESCRIPTION (provided by applicant): Approximately 170 million people are infected by hepatitis C virus (HCV) worldwide and many of these will go on to develop disease, primarily cirrhosis of the liver and hepatoma. A vaccine is required to help limit spread of the disease. Most effective vaccines developed to date elicit neutralizing antibodies (NAbs). There have been at least two major roadblocks en route to developing a component that elicits NAbs to HCV. The first is the lack of a conventional neutralization assay because of an inability to culture HCV in vitro. This roadblock has recently been at least partly dismantled by the development of systems for culturing HCV, albeit currently with certain limitations. The second roadblock is the great sequence variation of HCV found in infected donors that suggests a vaccine should elicit NAbs effective against a wide variety of different viruses, i.e. the vaccine should elicit broadly neutralizing antibodies. We propose a program to investigate the necessary conditions to induce a strong neutralizing antibody response against multiple HCV isolates and use the knowledge gained to design a NAb-inducing component of an HCV vaccine. We will systematically dissect NAb responses to HCV in natural infection, and isolate mAbs that are most potent and broad against neutralizing diverse isolates of HCV (Aim 1). These prototype mAbs will help us to identify neutralizing epitopes on HCV and we will explore the interaction between these epitopes and NAbs at the molecular level (Aim 2). We will apply knowledge gained from these molecular studies to the design of immunogens in order to produce NAb responses in animals (Aim 3). The prototype broadly neutralizing mAbs and Abs from animals immunized with the novel immunogens will be tested in a small animal model (Aim 4). PUBLIC HEALTH RELEVANCE: Hepatitis C virus infection is a major health problem worldwide and a vaccine is urgently needed to protect at-risk populations. We propose to develop antibody-inducing vaccine candidates against HCV. A key feature of our work is the rational design of vaccine candidates based on countering some of the tricks that this virus uses to evade antibodies.