Structure and immunogenicity of novel trimeric HIV-1 Env immunogens

新型三聚体 HIV-1 Env 免疫原的结构和免疫原性

• 批准号: 10020934
• 负责人: XIANGPENG KONG
• 金额: $ 76.7万
• 依托单位: NEW YORK UNIVERSITY SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-19 至 2024-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10020934
• 关键词: Acquired Immunodeficiency Syndrome; Animals; Antibody Formation; Antibody Response; Antigens; Binding Sites; Biological Assay; Complex; Computer Models; Cryoelectron Microscopy; DNA; Dental crowns; Development; Engineering; Epitopes; Extracellular Domain; Generations; Glycoproteins; Goals; HIV; HIV Envelope Protein gp120; HIV vaccine; HIV-1; Immune; Immunize; Immunologics; Individual; Macaca mulatta; Masks; Molecular Conformation; Oryctolagus cuniculus; Polysaccharides; Property; Protein Engineering; Proteins; Regimen; Resolution; Scaffolding Protein; Site; Specificity; Structure; Testing; Vaccine Design; Vaccines; Visualization; Work; base; design; immunogenic; immunogenicity; improved; infection risk; neutralizing antibody; novel; novel strategies; pandemic disease; scaffold; success; three-dimensional visualization; trimer core; vaccine development; virus envelope

A vaccine is needed to stop the HIV-1/AIDS pandemic, however, the development of a protective vaccine remains a great challenge and requires novel strategies. Various approaches to stabilize the whole extracellular domain of the HIV-1 envelope (Env) has led to greatly improved vaccine designs, e.g., the development of the SOSIP trimer, which, in addition to having provided a refined structural understanding of the Env trimer, is considered as a promising immunogen because it harbors all the known vulnerable sites on the Env trimer targeted by bnAbs. However, SOSIP-based immunogens have achieved only limited success due to unwanted distracting epitope sites that divert Ab responses to strain-specific ones. Unlike whole Env extracellular domain approaches, we have been using a divide-and-conquer strategy by starting with individual domains of the Env trimer to develop domain-specific immunogens which have the advantage of immune- focusing Ab responses to selected Env domains and epitopes and of avoiding induction of Abs to unwanted epitope regions. We started with the V1V2 domain, not only for its domain structure spatially located at the Env apex but also its Abs inversely correlate with the risk of infection in the RV144 trial, have developed a panel of trimeric V1V2 domain immunogens by scaffolding V1V2 of gp120 on trimeric non-HIV proteins, and demonstrated that they can induce V1V2-focused Ab responses. Moreover, further design efforts have resulted in a single chain tandem V1V2 trimer showing antigenic reactivity with trimer-specific bnAbs. We hypothesize that such V1V2-domain immunogens can be improved to present the native Env apex configuration by further structural characterization and engineering. To expand from the Env apex, we have then designed a ‘re-cored’ Env trimer immunogen by replacing the gp120 inner domain and gp41 in the prefusion trimer structure with a stable trimeric non-HIV scaffold protein; antigenicity tests demonstrated that this molecule harbors all key bnAb binding sites of the trimeric Env apex and EM visualization showed it to have a well-formed trimeric configuration. This novel construct provides a starting point to develop a trimeric immunogen that carries key vulnerable sites of the Env trimer which could become an attractive alternative to the SOSIP trimers, offering greater focus on the most promising bnAb epitopes. The goal of this R01 project is to structurally characterize these rationally-designed immunogens and further apply our structure-based platform to develop new generations of them so that they serve as effective immunogens targeting native trimeric configurations. We have three Aims. 1) Characterize and refine the trimeric V1V2-scaffold constructs mimicking the native prefusion conformation of the Env trimer apex. 2) Develop the re-cored Env trimer immunogen harboring key bnAb sites. 3) Test the immunogenicity of these refined immunogens in animals. At the completion of this project, our novel trimeric immunogens will be fully characterized and selected native-like immunogens can then be move forward in the pipeline for vaccine development and for NHP challenge studies.

但是，需要一种疫苗来阻止HIV-1/AIDS大流行，但是，受保护的疫苗的发展 仍然是一个巨大的挑战，需要新颖的策略。稳定整体的各种方法 HIV-1信封（ENV）的细胞外域已大大改善了疫苗设计，例如 SOSIP三聚体的开发，除了提供了精致的结构理解之外 env架子被认为是应许的免疫原，因为它藏有所有已知脆弱的地点 bnabs针对的ENV触发器。但是，基于SOSIP的免疫原仅取得了有限的成功 由于不需要分散注意力的情节站点，这些情节对特定于菌株的反应转移了。与整个环境不同 细胞外域方法，我们一直从个人开始使用分裂和诱使策略 ENV三聚体的结构域开发具有免疫优势的域特异性免疫原子 将AB的响应集中在选定的ENV域和表位上，并避免将ABS诱导到不必要的 表位区域。我们从V1V2域开始，不仅是因为其域结构在空间位于env 顶点，但它的腹肌与RV144试验中的感染风险相关，已经开发了一个小组 三聚体V1V2结构域通过trimeric非HIV蛋白上的gp120的脚手架V1V2和 证明它们可以诱导以V1V2为中心的AB反应。而且，进一步的设计工作已导致 在单链串联V1V2三聚体中，显示了触发特异性BNAB的抗原反应性。我们假设 可以改进这种V1V2域免疫原，以进一步呈现本机env Apex配置 结构表征和工程。为了从Env Apex扩展，我们然后设计了一个“重新计算” ENV三聚体免疫原通过替换GP120内域和gp41在诱发触发结构中 稳定的三聚体非HIV支架蛋白；抗原性测试表明，该分子包含所有关键BNAB 三聚合物Env Apex和EM可视化的结合位点，表明其具有良好的三聚体 配置。这种新颖的结构提供了开发携带钥匙的三聚体免疫原的起点 Env Trimer的脆弱地点，可能成为SOSIP三聚体的有吸引力的替代品 更加关注最有希望的BNAB表位。这个R01项目的目标是在结构上表征 这些合理设计的免疫原子，并进一步应用我们的基于结构的平台来开发新的 它们的几代人，以便它们充当靶向天然三聚体构型的有效免疫原。我们 有三个目标。 1）表征和完善模仿天然的三聚体V1V2-SCABTOLD构造 ENV触发器顶点的备源构象。 2）开发重新芯片的ENV触发免疫原携带钥匙 BNAB站点。 3）测试动物中这些精制免疫原子的免疫原性。完成此过程 项目，我们的新型三聚合物免疫原将充分表征并选择的类似天然的免疫原子可以 然后继续前进，以进行疫苗开发和NHP挑战研究。