SHIV Env-antibody coevolution as a molecular guide to HIV-1 V3 glycan targeted vaccine design

项目总结 事实证明，开发有效的HIV-1疫苗是一项艰巨的科学挑战。尽管几十年来 在研究中，没有免疫原能持续地诱导出有效的广谱中和抗体。 (BNAbs)。我们的科学前提是，在灵长类动物中诱导bNAb有三个主要障碍 以前的疫苗方法在很大程度上未能克服人类。它们是：一)高效和一致 多个HIV-1 bNAb前体B细胞的启动；II)免疫聚焦增强B细胞的靶向应答 保守的bNAb表位和远离靶标表位；以及iii)亲和力引导的B细胞系的成熟 选择增强的中和广度和效力。在这里，我们将逐一介绍这些要求。这 申请是现有HIVRAD奖项的竞争性续签，我们假设主要障碍是 合理的HIV-1疫苗设计是缺乏一个合适的灵长类动物模型，在该模型中可以普遍诱导bNAb 以及导致这种反应的分子、生物学和免疫学机制在一项 可复制和迭代的时尚。克服这一障碍是这笔赠款的主要目标之一，而且 在过去的五年里，我们在达到这一里程碑方面取得了实质性进展。我们通过开发一种 创造与临床相关的猴-人类免疫缺陷病毒(SIV)的新设计策略 原发HIV-1包膜蛋白，在恒河猴(RMS)中高效复制。接下来我们假设希夫- 感染的RMS可以用来识别具有诱发预定bNAb的倾向的HIV-1环境 表位特异性，从而允许对共同进化的详细和可重复的分子表征 导致亲和力成熟和广度的包膜蛋白和抗体途径。再一次，我们得到了大力支持 证据(科学371：eabd2638,2021年)。在这里，我们建议在此基础上建立并检验假设 阐明了环状病毒-抗体协同进化导致中和广度的分子途径。 受感染的RMS，结合对关键的Env-Ab谱系中间体的生物物理和免疫学分析，可以 为成功的种系靶向、基于B细胞系的免疫原设计提供分子“蓝图”。至 为了验证这一假设，我们提出了三个高度相关的研究项目和三个核心：项目1-环境抗体 SHIV感染的RMS中的共同进化导致V3糖蛋白bNAbs(Shaw)；项目2-优化体液免疫 针对HIV-1环境蛋白(Kelsoe)；项目3-免疫原设计以诱导对V3的多克隆bNAb反应 葡聚糖超氧化物(卫和)。这些项目将由核心A-行政(Shaw)；核心B-病毒和 抗体基因测序(HAHN)和核心C-生物信息学和统计学(WAGH)。这一事件的意义 拟议的研究可能影响深远：之前对HIV-1 SOSIP环境三聚体疫苗的研究已经 一般只在近交系动物中引起自体品系特异性NAB反应。如果我们能证明 用种系靶向、谱系为基础的SOSIP环境三聚体作为免疫原在小鼠体内一致诱导bNAbs RMS，这将代表着一项重大的科学进步，并成为艾滋病毒-1疫苗研究的新滩头阵地。

PROJECT SUMMARY The development of an effective HIV-1 vaccine has proven to be a daunting scientific challenge. Despite decades of research, there are no examples of immunogens that consistently elicit potent broadly neutralizing antibodies (bNAbs). Our scientific premise is that there are three principal obstacles to inducing bNAbs in primates and humans that prior vaccine approaches have largely failed to overcome. These are: i) efficient and consistent priming of multiple HIV-1 bNAb precursor B cells; ii) immunofocused boosting of B cell responses targeting conserved bNAb epitopes and away from off-target epitopes; and iii) affinity-guided maturation of B cell lineages to select for enhanced neutralization breadth and potency. Here, we address each of these requirements. This application is a competitive renewal of an existing HIVRAD award where we hypothesized that a major roadblock to rational HIV-1 vaccine design is the lack of a suitable primate model in which bNAbs can be commonly induced and the molecular, biological and immunological mechanisms responsible for such responses studied in a reproducible and iterative fashion. Overcoming this roadblock was one of the major goals of that grant, and over the past five years we have made substantial progress in reaching this milestone. We did this by developing a novel design strategy for creating simian-human immunodeficiency viruses (SHIV) that bear clinically-relevant primary HIV-1 Envs and that replicate efficiently in rhesus macaques (RMs). We next hypothesized that SHIV- infected RMs could be used to identify HIV-1 Envs that have a propensity for eliciting bNAbs of predetermined epitope specificity, thus allowing for a detailed and reproducible molecular characterization of the coevolutionary pathways of Env and Ab that lead to affinity maturation and breadth. Again, we obtained strong supporting evidence (Science 371:eabd2638, 2021). Here we propose to build on this foundation and to test the hypothesis that elucidation of the molecular pathways of Env-Ab coevolution leading to neutralization breadth in SHIV- infected RMs, combined with biophysical and immunological analyses of key Env-Ab lineage intermediates, can provide a molecular “blueprint” for successful germline-targeted, B cell lineage-based immunogen design. To test this hypothesis, we propose three highly inter-related research projects and three cores: Project 1 - Env-Ab coevolution in SHIV infected RMs leading to V3 glycan bNAbs (Shaw); Project 2 - Optimizing humoral immunity to HIV-1 Env proteins (Kelsoe); Project 3 - Immunogen design to elicit polyclonal bNAb responses to the V3 glycan supersite (Wiehe). These projects will be enabled by Core A – Administrative (Shaw); Core B – Viral and antibody gene sequencing (Hahn); and Core C – Bioinformatics and statistics (Wagh). The significance of the proposed studies is potentially far-reaching: previous studies of HIV-1 SOSIP Env trimer vaccinations have generally elicited only autologous strain-specific Nab responses in outbred animals. If we can demonstrate consistent induction of bNAbs using germline-targeted, lineage-based SOSIP Env trimers as immunogens in RMs, it would represent a major scientific advance and a new beachhead for HIV-1 vaccine research.