Structure-Based Designs of HIV-1 Immunogens Targeting Germline Precursors of Broadly Neutralizing Antibodies

项目摘要/摘要 广谱中和抗体(BNAbs)可能是HIV-1疫苗的重要组成部分。艾滋病病毒-- 1包膜糖蛋白是bNAbs的唯一靶点，一直是免疫原设计的焦点。还没有 不同的重组(Rec)环境不显示可检测到的与某些bNAb的推测胚系(G1)的结合， 例如VRC01类bNAb，这是本提案的重点。能够结合glVRC01的REC环境 BNAbs已被设计并诱导产生glVRC01 bNAbs作为免疫原。 然而，这些新的免疫原不足以诱导glVRC01类bNAbs成熟到其 广泛的中和形式。在这里，我们建议使用新的试剂作为免疫原来指导发展 VRC01类bNAbs的制备方法：1)用含有短链糖链的免疫原免疫转基因小鼠 如果这些能更有效地启动免疫反应，以适应HIV-1环境多糖屏蔽和 2)结合免疫学和生物物理学(包括原子级结构)表征。我们 假设这样的免疫原已经知道如何适应短链糖链，因此更多 容易成熟的。我们的初步数据显示，这种抗原增加了与前体的结合 GlVRC01类抗体。具有结构信息的单抗的测序 将提供来自动物的疫苗引发的抗体与 免疫原：更好地了解新型疫苗诱导的mAb靶向表位将有助于我们识别 最好的增强免疫原，用于未来的免疫研究，从而指导艾滋病毒-1疫苗的设计。

PROJECT SUMMARY/ABSTRACT Broadly neutralizing antibodies (bNAbs) are likely to be an important component of an HIV-1 vaccine. The HIV- 1 Envelope (Env) glycoprotein is the sole target of bNAbs and has been a focus of immunogen designs. Yet diverse recombinant (rec) Envs do not display detectable binding to the inferred germline (gl) of certain bNAbs, such as the VRC01-class bNAbs, which are the focus of this proposal. Rec Envs capable of binding glVRC01 bNAbs have been designed and induced the production of glVRC01 bNAbs when used as immunogens. However, these novel immunogens are not sufficient to induce the maturation of glVRC01-class bNAbs to their broad neutralization forms. Here we propose to use novel reagents as immunogens to guide the development of VRC01-class bNAbs by: 1) immunizing knock-in mice with immunogens harboring short glycans to evaluate if these could more efficiently prime immune responses that will accommodate the HIV-1 Env glycan shield and 2) combining immunological and biophysical (including atomic level structures) characterization. We hypothesize that such immunogens will already know how to accommodate short glycans and thus be more amenable to maturation. Our preliminary data show that such antigen has increased binding to precursors glVRC01-like antibodies. The sequencing of monoclonal antibodies (mAbs) along with structural information will provide molecular details on the interactions between the vaccine-elicited antibodies from animals and the immunogens: better understanding the epitopes targeted by the novel vaccine-elicited mAbs will help us identify the best boost immunogen for future immunizations studies and thus guide HIV-1 vaccine design.