Novel HIV-1 Env trimer probes for efficient isolation of broadly neutralizing antibodies

摘要 HIV-1包膜(Env)探针是分离广谱中和抗体(BNAbs)和 HIV-1bNAbs对指导环境免疫原设计特别有用。作为当前的探测器和 方法的局限性阻碍了从大量个体中有效地分离bNab，我们 建议开发基于VSV的新型探针，在表面展示致密的HIV-1环境三聚体以分离 BNAbs。我们推测，正确构建的gp140 VSV探针为bNab提供了一个强大的工具 从大量(n&>50)分支B和非B中分离并允许有效地鉴定bNAbs 分支感染的个体，其中一些具有未知的新表位。为了检验这一假设，我们合作 与安德烈斯·芬齐博士一起研究来自加拿大蒙特利尔的B分支感染队列的样本，以及 与Phillipe Nyambi博士一起研究雅温得多分支感染队列的样本， 喀麦隆。我们已经筛选了111个蒙特利尔和260个喀麦隆血浆，确定了32个和13个 分别为具有bNab活性的捐赠者。我们建议1)构建、表征和优化 Gp140.VSV探针用于各种Clade-B和非B环境，2)应用gp140.VSV探针来分离bNAbs 来自&gt；50分支B和非B分支感染的广谱中和剂，以及3)确定新的 分离出bNAb并定义新的bNab基因组成。在试点实验中，我们生成了一个 Gp140.VSV探针在表面显示HIV-1AD17环境三聚体；使用该探针，我们恢复了 两种截然不同且新颖的bNAb，取自一名感染B分支病毒的蒙特利尔捐献者。这一初步结果支持我们的 假设并提供了一个概念验证，即gp140.VSV探针可以导致新的 BNAbs。我们预计将通过这种探测方法识别50个新的bNAb，其中一些将 确定新的环境目标和bNab基因成分。这些bNAbs的加入将补充 其他扩展bNab库并促进我们对bNab表位和基因的理解 组合物，从而促进环境免疫原设计和免疫后分析。

SUMMARY HIV-1 envelope (Env) probes are key to the isolation of broadly neutralizing antibodies (bnAbs) and the HIV-1 bnAbs are particularly useful to inform and guide Env immunogen design. As current probes and methods have limitations that hinder efficient bnAb isolation from large numbers of individuals, we propose to develop novel VSV-based probes to display dense HIV-1 Env trimers on the surface to isolate bnAbs. We hypothesize that properly constructed gp140.VSV probes provide a powerful tool for bnAb isolation and allow efficient identification of bnAbs from a large number (n>50) of clade-B and non-B clade infected individuals, some with undefined novel epitopes. To test this hypothesis, we collaborate with Dr. Andres Finzi to study samples from a clade-B infected cohort based in Montreal, Canada, and with Dr. Phillipe Nyambi to study samples from a multi-clade infected cohort based in Yaounde, Cameroon. We have screened 111 Montreal and 260 Cameroon plasmas and identified 32 and 13 donors with bnAb activity, respectively. We propose to 1) construct, characterize, and optimize gp140.VSV probes for various clade-B and non-B Envs, 2) apply gp140.VSV probes to isolate bnAbs from >50 clade-B and non-B clade infected broad neutralizers, and 3) determine the epitopes of newly isolated bnAbs and define new bnAb genetic compositions. In pilot experiments, we generated a gp140.VSV probe displaying the HIV-1 AD17 Env trimer on the surface; using this probe, we recovered two distinct and novel bnAbs from a clade-B infected Montreal donor. This preliminary result supports our hypothesis and provides a proof-of-concept that the gp140.VSV probe can lead to the isolation of novel bnAbs. We anticipate that >50 new bnAbs will be identified by this probing method and some of them will define new Env targets and bnAb genetic compositions. The addition of these bnAbs will complement others to expand the bnAb repertoire and advance our understanding of the bnAb epitopes and genetic compositions, thus facilitating Env immunogen design and post-immunization analysis.