A VLP-based platform for Vaccine Discovery

描述（由申请人提供）：病毒样颗粒（vlp）以高度免疫原性的形式为展示抗原提供了极好的平台。然而，到目前为止，VLPs还没有被用于鉴定抗原表位。相比之下，丝状噬菌体展示是一种有效的抗原表位鉴定技术，但这些噬菌体的免疫原性较差。在本文中，我们描述了一个基于RNA噬菌体MS2的VLPs的新平台，它既可以作为表位亲和力选择的底物，也可以直接作为免疫原。由于亲和选择和免疫原呈递是在一个单一的结构平台上进行的，我们期望选择的表位将是目标表位的更忠实的分子模拟物。为了验证这一想法，我们使用我们的系统使用MS2噬菌体文库选择抗原表位。该文库将使用识别明确的线性表位和复杂构象表位的单克隆抗体（mab）进行筛选。在AIM 1中，我们将开发技术来优化选择具有高亲和力的抗体表位。在AIM 2中，我们将评估选择的重组VLPs的亲和力，测量它们的免疫原性，并确定这些用单克隆抗体选择的VLPs是否会引起类似的抗体反应。我们相信这项技术代表了一种在高度免疫原性环境中选择表位的新方法，可以模仿它们的天然构象，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，例如使用广泛中和的单克隆抗体来对抗感兴趣的传染病靶点（例如针对丙型肝炎病毒、人乳头瘤病毒和艾滋病毒的单克隆抗体，但还有许多其他潜在靶点）。此外，由于我们已经证明基于vlp的免疫原可以有效地引发对自身抗原的抗体反应，我们也可以利用这种技术开发用于治疗性单克隆抗体的疫苗替代品，用于治疗慢性疾病。

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.