Project 2. Animal studies to elucidate the optimal sequence of Env immunogens for induction of distal MPER bnAbs

最近从HIV感染者中分离出几种关键的广谱中和抗体（bnAb）， 开发新策略以诱导类似类别的疫苗诱导的阶段 中和抗体反应。在这些最近的bnAb分离株中，10E8和DH511都靶向远端 HIV包膜（Env）gp41上的MPER表位。DH511谱系抗体的结构和功能分析 已经表明远端MPER表位bnAb是最广泛和有效的HIV中和抗体之一， 抗体，从而确立它们对疫苗设计的重要性。对于免疫原设计，我们将与 Scripps团队在项目1中，并使用我们新的计算程序，抗原受体突变分析仪 用于检测低可能发生率（ARMADiLLO），允许定义关键抗体 诱导体细胞突变，以确定成功疫苗需要靶向的关键IA。的 使用携带BnAb及其UCA（未突变共同祖先）的BCR的KI小鼠模型已经是一种有效的方法。 一项重大进展，将允许优化未突变的前体靶向顺序免疫原， 允许跟踪候选免疫原的抗体亲和力成熟过程。我们将使用新的 分离的DH511远端MPER bnAb克隆谱系UCA，中间抗体（IA）和bnAb作为试剂 在此基础上设计连续的免疫原，并在一个强大的新的基因敲入中测试这些免疫原， 由Fred Alt实验室在Animal Models Core中开发的bnAb发育的小鼠模型。 此外，最近在理解恒河猴免疫生物学方面的突破， 在整个疫苗接种方案中，需要确定和遵循中和抗体谱系。我们的具体 目标是： 目标2.1。定义成功疫苗的功能性不太可能的中间抗体（IA）体细胞突变 将需要选择以导致bnAb诱导。 目标2.2。定义来源于项目1的免疫原，其激活DH511未突变的前体， 在小动物模型和恒河猴中的中间抗体。 项目2中的研究将与项目1和小动物模型核心中的研究协同作用， 免疫原的设计将导致亲和力成熟的远端MPER bnAb的起始和选择。

The recent isolation of several key broad neutralizing antibodies (bnAb) from HIV infected subjects have set the stage for the development of novel strategies for the induction of similar classes of vaccine induced neutralizing antibody responses. Among these recent bnAb isolates, both 10E8 and DH511 target the distal MPER epitopes on HIV Envelope (Env) gp41. Structural and functional analysis of DH511 lineage antibodies have shown that distal MPER epitope bnAbs are among the most broad and potent HIV neutralizing antibodies, thus establishing them as important for vaccine design. For immunogen design, we will partner with the Scripps team in Project 1, and use our new computational program, Antigen Receptor Mutation Analyzer for Detection of Low Likelihood Occurrences (ARMADiLLO), that allows for definition of the critical antibody somatic mutations to be induced, to determine the key IAs that a successful vaccine will need to target. The use of KI mouse models bearing BCR of BnAbs and their UCAs (Unmutated Common Ancestor) has been a major advance that will allow the optimization of unmutated precusor-targeting sequential immunogens, and allow the course of antibody affinity maturation of candidate immunogens to be followed. We will use the newly isolated DH511 distal MPER bnAb clonal lineage UCA, intermediate antibodies (IAs) and bnAbs as reagents upon which to design sequential immunogens and to test these immunogens in a powerful, new knock-in mouse model of bnAb development developed by the Fred Alt laboratory in the Animal Models Core. Moreover, recent breakthoughs in understanding Rhesus macaque immunobiology has allowed similar HIV neutralizing antibody genealogies to be defined and followed throughout vaccination regimens. Our specific Aims are: Aim 2.1. Define functional improbable intermediate antibody (IA) somatic mutations that a successful vaccine will need to select to lead to bnAb induction. Aim 2.2. Define immunogens derived from Project 1 that activate DH511 unmutated precursors and intermediate antibodies in small animal models and in Rhesus macaques. The studies in Project 2 will synergize with studies in Project 1 and Small Animal Models Core to lead to novel designs of immunogens that will lead to initiation and selection of affinity matured distal MPER bnAbs.