Vaccines to Induce Functional Antibodies Targeting the V2 Loop

HIV-1包膜(Env)糖蛋白的各种形式并不是理想的免疫原，因为 它们很难诱导出具有广泛抗病毒功能的抗体，抗体反应可持续6个月。至 克服这些限制，表位-支架免疫原可以用来集中抗体反应 环境上的脆弱部位；然而，艾滋病毒表位-支架免疫原的设计充满了 失败了很多次。然而，表位-支架疫苗候选已经成功开发出来。 对抗流感和奈瑟氏菌，我们和其他人已经成功地设计了几个V3支架和V3 具有明显抗原性和免疫原性的多肽免疫原，导致诱导HIV-1 交叉分支中和Abs。在这个项目中，我们建议将免疫反应集中在V2上 GPL20区域。直到最近，该区域作为疫苗开发的目标几乎被忽视， 但它作为疫苗靶点的重要性最近得到了数据的支持，数据表明抗V2抗体可以 高度交叉反应，显示中和活性，捕获病毒颗粒，并阻断gp120/a4p7相互作用。 支持将V2作为疫苗设计的有希望的抗原也来自于 来自RV144临床疫苗试验的样本。对于这个项目，我们将应用我们为其开发的平台 产生V3-支架免疫原以产生用于增强的V2-支架免疫原 DNA Env免疫后的抗体反应。对于目标1.1，我们将为脚手架构建V2插件 基于人V2多克隆和单克隆抗体(MAbs)良好特异性的免疫原，以及 生物信息学和分子模型数据。在目标1.2中，我们将评估抗-DNA抗体的患病率和功能 V2抗体具有不同的特异性，并阐明这些抗体相对于感染艾滋病毒的分支有何不同。对于AIM 1.3， 我们将从非B分支感染的供者中筛选并鉴定新的人类V2特异性单抗。 喀麦隆感染了能产生最广泛和功能最强的抗V2抗体的支系。最后，在 从Aim 1.2和1.3的结果中选择与最广泛、最有效的 和多功能抗V2多克隆和单抗，我们将在目标1.4中测试选定的V2的免疫原性 用Env DNA引发兔和非人灵长类动物免疫原增强支架。这个 该项目的最终目标是在兔和非人灵长类动物中诱导抗-V2抗体 协调保护的跨部门抗病毒活动。

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.