Vaccines to Induce Functional Antibodies Targeting the V2 Loop

各种形式的HIV-1包膜（Env）糖蛋白不能作为理想的免疫原， 它们很难诱导具有广泛抗病毒功能的Ab（Ab），并且Ab应答持续<6个月。到 克服这些限制，表位-支架免疫原可用于将Ab应答集中在 Env上的脆弱位点;然而，HIV表位支架免疫原的设计充满了 许多失败。尽管如此，已经成功地开发了表位-支架疫苗候选物 针对流感和奈瑟氏球菌，我们和其他人已经成功地设计了几种V3-支架和V3 具有可证实的抗原性和免疫原性的肽免疫原，导致诱导HIV-1 交叉进化枝中和抗体在这个项目中，我们建议将免疫反应集中在V2上， GPL 20的区域。直到最近，这一地区作为疫苗开发的目标几乎被忽视， 但其作为疫苗靶点的重要性最近得到了数据的支持，数据显示抗V2抗体可以 高度交叉反应性、显示中和活性、捕获病毒颗粒并阻断gp 120/a4 p7相互作用。 将V2作为疫苗设计的有希望的抗原的支持也来自于以下试验性研究： RV 144临床疫苗试验的样本。对于这个项目，我们将应用我们开发的平台， 产生V3-支架免疫原以产生用于加强的V2-支架免疫原 用DNA Env.对于目标1.1，我们将构建V2胫骨衬垫， 基于人V2多克隆和单克隆抗体（mAb）的良好特异性的免疫原，以及 生物信息学和分子建模数据。在目标1.2中，我们将评估抗- 不同特异性的V2抗体，并阐明这些抗体相对于感染HIV的进化枝是如何不同的。对于目标1.3， 我们将从非进化枝B感染的供体中选择和表征新的人V2特异性mAb， 喀麦隆感染了诱导最广泛和功能性抗V2抗体的进化枝。最后经过 从目的1.2和1.3的结果中选择V2-支架蛋白，其与最广泛、有效的 和多功能抗V2多克隆抗体和单克隆抗体，我们将在目的1.4中测试所选V2的免疫原性 在用Env DNA引发后，在兔和非人灵长类动物中增强免疫原的支架。的 本项目的最终目标是在兔和非人灵长类动物中诱导抗V1-V2抗体， 介导保护作用的跨进化枝抗病毒活性。

The various forms of the HIV-1 envelope (Env) glycoproteins do not serve as ideal immunogens because they poorly induce Abs (Abs) with broad anti-viral functions, and the Ab response lasts <6 months. To overcome these limitations, epitope-scaffold immunogens can be used to focus the Ab response on vulnerable sites on the Env; however, the design of HIV epitope-scaffold immunogens has been fraught with many failures. Nevertheless, epitope-scaffold vaccines candidates have been successfully developed against influenza and Neisseria, and we and others have succeeded in designing several V3-scaffold and V3 peptide immunogens with demonstrable antigenicity and immunogenicity, resulting in the induction of HIV-1 cross-clade neutralizing Abs. In this Project, we propose to focus the immune response on the V2 region of gpl 20. Until recently, this region was virtually overlooked as a target for vaccine development, but its importance as a vaccine target has been recently supported by data showing that anti-V2 Abs can be highly cross-reactive, display neutralizing activity, capture virus particles, and block gp120/a4p7 interaction. Support for pursuing V2 as a promising antigen for vaccine design also comes from pilot studies with specimens from the RV144 clinical vaccine trial. For this Project, we will apply the platform we developed for generating V3-scaffold immunogens to the production of V2-scaffold immunogens to be used for boosting the Ab response after priming with DNA Env. For Aim 1.1, we will construct V2 inserts for scaffolded immunogens based on the fine specificity of human V2 polyclonal and monoclonal Abs (mAbs), and on bioinformatics and molecular modeling data. In Aim 1.2, we will assess the prevalence and function of anti- V2 Abs of different specificities and clarify how these differ relative to the infecting HIV clade. For Aim 1.3, we will select and characterize new human V2-specific mAbs derived from non-clade B-infected donors from Cameroon infected with the clades that induce the most broad and functional anti-V2 Abs. Finally, after selecting V2-scaffold proteins which, from the results of Aim 1.2 and 1.3, react with the most broad, potent and multifunctional anti-V2 polyclonal and mAbs, we will, in Aim 1.4, test the immunogenicity of selected V2 scaffold boosting immunogens in rabbits and non-human primates after priming with Env DNA. The ultimate goal of this Project is to induce antl-V2 Abs in rabbits and non-human primates that display cross-clade anti-viral activities that mediate protection.