Exploring the membrane-related components of HIV-1 Env for immunogen design

总结 从我们最近的工作结构的见解提供了一个强有力的科学前提探索膜相关的 HIV-1包膜糖蛋白（Env）的组分，包括膜近端外部区域（MPER）， 跨膜结构域（TMD）和胞质尾区（CT），用于疫苗开发。我们的数据表明 所有这些区域都影响Env胞外域的稳定性和抗原性。主要广泛中和 HIV-1 Env上的抗体（bnAb）表位包括CD 4结合位点、V1 V2-聚糖、V3-聚糖、融合蛋白、CD 4 + T细胞、CD 4 + T 肽/gp 120-gp 41界面和MPER。这些表位的最佳呈现，对于它们的免疫功能至关重要。 抗原性和免疫原性取决于Env三聚体的结构和构象。最近，Fusion 基于肽的免疫原在动物模型中诱导了强有力的交叉进化枝中和反应， 这表明bnAb可以通过疫苗接种引发。在这个研究项目中，我们的中心假设是， 具有不同程度bnAb表位的不同构象的合理设计的HIV-1 Env免疫原 暴露诱导不同B细胞应答，这可能导致在动物模型中产生不同的bnAb 以及HIV-1疫苗免疫原设计的新策略。该研究小组由一群 杰出的研究人员，具有不同但互补的专业知识，以开展拟议的研究。这群 在蛋白质工程、生产和表征、B细胞生物学和 动物模型中的疫苗学，以及疫苗引发的抗体应答的详细分析。本集团 成员在HIV-1和SARS-CoV-2相关项目上有着广泛的合作历史。球队 将利用新确定的HIV-1 Env膜相关成分的结构， 两种创新的免疫原设计策略：（1）可溶性Env三聚体免疫原和（2）膜结合 完整Env三聚体免疫原。我们提出了两个具体目标来检验假设：目标1。我们会设计， 以蛋白质和mRNA形式表征和产生基于Env的免疫原， Env免疫原及其与抗体复合物的研究。目标2.我们将评估免疫原性 在VelocImmune人抗体小鼠中的新型Env蛋白免疫原和mRNA疫苗。

Summary Structural insights from our recent work provide a strong scientific premise for exploring the membrane-related components of HIV-1 envelope glycoprotein (Env), including the membrane proximal external region (MPER), the transmembrane domain (TMD) and the cytoplasmic tail (CT), for vaccine development. Our data indicate that all these regions influence the stability and antigenicity of the Env ectodomain. Major broadly neutralizing antibody (bnAb) epitopes on HIV-1 Env include CD4 binding site, V1V2-glycan, V3-glycan, the fusion peptide/gp120-gp41 interface and the MPER. The optimal presentation of these epitopes, critical for their antigenicity and immunogenicity, depends on the Env trimer organization and conformation. Recently, the fusion peptide-based immunogens have induced robust cross-clade neutralizing responses in animal models, suggesting that bnAbs may be elicited by vaccination. In this research project, our central hypothesis is that rationally designed HIV-1 Env immunogens in different conformations with various degrees of bnAb epitope exposure induce different B cell responses, which may lead to production of diverse bnAbs in animal models and to new strategies for HIV-1 vaccine immunogen design. The research team is formed by a group of outstanding investigators with diverse yet complementary expertise to carry out the proposed studies. This group has extensive experience in protein engineering, production and characterization, in B cell biology and vaccinology in animal models, and in detailed analysis of vaccine-elicited antibody responses. The group members have an extensive history of working together on HIV-1 and SARS-CoV-2 related projects. The team will capitalize on the newly determined structures of the membrane-related components of HIV-1 Env to develop two innovative immunogen-design strategies: (1) soluble Env trimer immunogens and (2) membrane-bound intact Env trimer immunogens. We propose two Specific Aims to test the hypothesis: Aim 1. We will design, characterize and produce Env-based immunogens in both the protein and mRNA forms and perform structural studies of Env-based immunogens and their complexes with antibodies. Aim 2. We will evaluate immunogenicity of novel Env-based protein immunogens and mRNA vaccines in VelocImmune human antibody mice.