A VLP-based platform for Vaccine Discovery

描述(申请人提供)：病毒样颗粒(VLP)是以高度免疫原性形式展示抗原的极佳平台。然而，到目前为止，VLP还没有被用于识别抗原表位。相反，丝状噬菌体展示是鉴定抗原表位的有用技术，但这些噬菌体不能产生良好的免疫原性。在这个建议中，我们描述了一个基于RNA噬菌体MS2的VLP的新平台，它既可以作为表位亲和选择的底物，也可以直接作为免疫原。由于亲和选择和免疫原呈递是在单一的结构平台上进行的，我们预计所选的表位将是目标表位的更忠实的分子模拟。作为对这一想法的测试，我们使用我们的系统使用MS2噬菌体文库来选择抗原表位。该文库将使用识别明确定义的线性表位和复杂构象表位的单抗进行筛选。在目标1中，我们将开发技术来优化对选择抗体具有高亲和力的表位的选择。在AIM 2中，我们将评估选择的重组VLP的亲和力，测量它们的免疫原性，并确定这些用单抗选择的VLP是否能引起相似的抗体反应。我们相信，这项技术代表了一种在模仿其天然构象的高度免疫原性背景下选择表位的新方法，并将对疫苗开发产生重大影响。这些研究的成功完成将为选择潜在的疫苗奠定基础，例如，使用广泛中和抗感兴趣的传染病靶点的单抗(例如针对丙型肝炎病毒、人乳头瘤病毒和艾滋病毒的单抗，但还有许多其他潜在的靶点)。此外，由于我们已经证明基于VLP的免疫原可以有效地诱导对自身抗原的抗体反应，我们也可以利用这一技术来开发用于治疗慢性疾病的治疗性单抗的疫苗替代品。 公共卫生相关性：在这个项目中，我们将使用一种新的基于病毒样颗粒(VLP)的噬菌体展示系统来发现疫苗。

DESCRIPTION (provided by applicant): Virus-like particles (VLPs) make excellent platforms for displaying antigens in a highly immunogenic format. However, to date, VLPs have not been used to identify antigenic epitopes. In contrast, filamentous phage display is a useful technique for identification of antigenic epitopes, but these phage make poor immunogens. In this proposal, we describe a new platform based on VLPs of the RNA bacteriophage MS2, which serves both as a substrate for epitope affinity-selection and directly as an immunogen. Because affinity-selection and immunogen presentation are conducted on a single structural platform, we expect that selected epitopes will be more faithful molecular mimics of the target epitope. As a test of this idea, we use our system to select antigenic epitopes using an MS2 phage library. This library will be screened using monoclonal antibodies (mAbs) that recognize a well-defined linear epitope and a complex conformational epitope. In AIM 1, we will develop techniques to optimize the selection of epitopes with high affinity for the selecting antibodies. In AIM 2, we will assess the affinities of selected recombinant VLPs, measure their immunogenicity, and determine whether these VLPs, which are selected with mAbs, elicit similar antibody responses. We believe that this technology represents a new way to select epitopes in a highly immunogenic context that mimics their native conformation, and will have significant implications for vaccine development. Successful completion of these studies will lay the groundwork for selections of potential vaccines using, say, broadly neutralizing mAbs against infectious disease targets of interest (mAbs targeting Hepatitis C virus, Human Papillomavirus, & HIV are examples, but there are many other potential targets). Moreover, since we have shown that VLP-based immunogens can effectively elicit antibody responses to self-antigens, we could also use this technique to develop vaccine alternatives to therapeutic mAbs used to treat chronic diseases. PUBLIC HEALTH RELEVANCE: In this project, we will use a new phage display system, based on virus-like particles (VLPs), for vaccine discovery.