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

项目概要/摘要 广泛中和抗体（bNAb）可能是HIV-1疫苗的重要组成部分。艾滋病毒- 1包膜糖蛋白（Env）是bNAb的唯一靶点，并且一直是免疫原设计的焦点。然而 不同的重组（rec）Env不显示与某些bNAb的推断的种系（g1）的可检测的结合， 例如VRC 01级bNAb，这是本提案的重点。能够结合glVRC 01的Rec Envs 已经设计了bNAb，并在用作免疫原时诱导glVRC 01 bNAb的产生。 然而，这些新的免疫原不足以诱导glVRC 01类bNAb成熟为它们的抗原。 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，以指导发展 1）用含有短聚糖的免疫原免疫敲入小鼠以评估VRC 01类bNAb的表达。 如果这些可以更有效地引发免疫反应，将容纳HIV-1 Env聚糖盾牌， 2)结合免疫学和生物物理学（包括原子水平结构）表征。我们 假设这些免疫原已经知道如何容纳短聚糖， 适合成熟。我们的初步数据表明，这种抗原与前体的结合增加， glVRC 01样抗体。单克隆抗体（mAb）的测序连同结构信息沿着 将提供关于疫苗引起的动物抗体与疫苗之间相互作用的分子细节。 免疫原：更好地了解新型疫苗诱导的mAb靶向的表位将有助于我们识别 为未来的免疫研究提供最佳的加强免疫原，从而指导HIV-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.