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

项目摘要 研制有效的HIV-1疫苗已被证明是一项艰巨的科学挑战。尽管几十年 研究表明，没有免疫原的例子，始终引发有效的广泛中和抗体 （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， 人类，以前的疫苗方法在很大程度上未能克服。它们是：一）高效和一致 引发多种HIV-1 bNAb前体B细胞; ii）免疫聚焦加强靶向HIV-1 bNAb前体B细胞的B细胞应答 保守的bNA B表位和远离脱靶表位;和iii）亲和力引导的B细胞谱系的成熟 以选择增强的中和宽度和效力。在这里，我们将满足这些要求中的每一个。这 应用程序是现有HIVRAD奖项的竞争性更新，我们假设主要障碍 合理的HIV-1疫苗设计缺乏一个合适的灵长类动物模型，其中bNAb通常可以诱导 以及在一个研究中负责这种反应的分子、生物学和免疫学机制。 可重复和迭代的方式。克服这一障碍是该赠款的主要目标之一， 过去五年，我们在达到这个里程碑方面取得了重大进展。我们通过开发一个 一种新的设计策略，用于产生携带临床相关的 原代HIV-1 Env，并在恒河猴（RM）中有效复制。我们接下来假设SIV- 感染的RM可用于鉴定HIV-1 Env，这些Env倾向于引发预定的bNAb， 表位特异性，从而允许详细的和可重复的分子表征的共同进化 Env和Ab的途径，导致亲和力成熟和广度。我们再次获得了强有力的支持 证据（科学371：eabd 2638，2021）。在这里，我们建议建立在这个基础上，并测试假设 阐明Env-Ab共同进化的分子途径导致SHIV-1中和宽度， 感染的RM，结合关键Env-Ab谱系中间体的生物物理学和免疫学分析，可以 为成功的种系靶向的、基于B细胞谱系的免疫原设计提供了分子“蓝图”。到 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RM的共同进化导致V3聚糖bNAb（Shaw）;项目2 -优化体液免疫 项目3 -免疫原设计以引发对V3的多克隆bNAb应答 聚糖超位点（Wiehe）。这些项目将通过核心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）。的意义 拟议的研究可能是深远的：以前的HIV-1 SOSIP Env三聚体疫苗接种研究 通常在远交动物中仅引起自体品系特异性Nab应答。如果我们能证明 使用种系靶向的、基于谱系的SOSIP Env三聚体作为免疫原， 它将代表一个重大的科学进步和HIV-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.