A VLP-based platform for Vaccine Discovery

描述（由申请人提供）：病毒样颗粒（VLP）是以高免疫原性形式展示抗原的极好平台。然而，迄今为止，VLP尚未用于鉴定抗原表位。相反，丝状噬菌体展示是鉴定抗原表位的有用技术，但这些噬菌体产生差的免疫原。在这个建议中，我们描述了一个新的平台的基础上的RNA噬菌体MS2，它既作为一个基板的表位亲和选择，并直接作为一种免疫原的VLPs。由于亲和选择和免疫原呈递在单一结构平台上进行，我们预期所选表位将是靶表位的更忠实的分子模拟物。作为这个想法的测试，我们使用我们的系统来选择抗原表位使用MS2噬菌体文库。将使用识别明确定义的线性表位和复杂构象表位的单克隆抗体（mAb）筛选该文库。在AIM 1中，我们将开发技术来优化选择抗体的高亲和力表位的选择。在AIM 2中，我们将评估所选重组VLP的亲和力，测量其免疫原性，并确定这些用mAb选择的VLP是否引发类似的抗体应答。 我们相信，这项技术代表了一种新的方式来选择表位在一个高度免疫原性的情况下，模仿其天然构象，并将有重大意义的疫苗开发。这些研究的成功完成将为选择潜在的疫苗奠定基础，例如，针对感兴趣的传染病靶标的广泛中和mAb（靶向丙型肝炎病毒，人类乳头瘤病毒和HIV的mAb是例子，但还有许多其他潜在的靶标）。此外，由于我们已经表明基于VLP的免疫原可以有效地引发对自身抗原的抗体应答，我们还可以使用这种技术来开发用于治疗慢性疾病的治疗性mAb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噬菌体展示系统，基于病毒样颗粒（VLP），用于疫苗发现。

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.