Project 2: PanbetaCoV protein vaccine design

项目2：PanbetaCoV蛋白疫苗设计

• 批准号: 10842503
• 负责人: Kevin Wiehe
• 金额: $ 282.88万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-16 至 2024-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10842503
• 关键词: 2019-nCoV; Address; Adjuvant; Alphavirus; Animal Model; Animals; Antibodies; Antibody Response; Antibody titer measurement; Antigens; Avidity; Binding; COVID-19 vaccine; Cell surface; Chiroptera; Complex; Coronavirus; Coronavirus spike protein; Cross Reactions; Cryoelectron Microscopy; Development; Disease Outbreaks; Ensure; Epitopes; Ferritin; Follicular Dendritic Cells; Future; Goals; HIV; HIV vaccine; Health; Human; Immunity; Immunize; Immunologic Monitoring; Influenza; Macaca; Mediating; Merbecovirus; Messenger RNA; Methods; Middle East Respiratory Syndrome; Molecular Conformation; Mus; Mutation; Peptides; Persons; Proteins; SARS coronavirus; Sarbecovirus; Site; Structure; Structure of germinal center of lymph node; Surface; System; Techniques; Testing; Therapeutic; Translating; Vaccine Design; Vaccines; Variant; Viral; Wild Type Mouse; Work; aluminum sulfate; betacoronavirus; betacoronavirus vaccine; coronavirus pandemic; cross reactivity; design; expectation; immunogenic; influenza virus vaccine; lipid nanoparticle; nanoparticle; neutralizing antibody; nonhuman primate; novel; pandemic coronavirus; pandemic disease; pandemic potential; pandemic preparedness; phase III trial; prevent; programs; protein structure; rational design; receptor binding; research clinical testing; spillover event; trafficking; vaccine candidate; vaccine development; vaccine-induced antibodies; zoonotic coronavirus

Abstract – Project 2 Animal betacoronaviruses (betaCoVs), such as those that gave rise to SARS-CoV-1, MERS, and now SARS- CoV-2, represent a significant, continuous threat to human health. Vaccines can provide pre-existing immunity to future zoonotic coronaviruses. A major limitation of the current effective vaccines to SARS-CoV-2 is that they likely will only protect SARS-CoV-2 isolates that are nearly identical to the Wuhan isolate used in the vaccines. Thus, the world remains vulnerable to SARS-CoV-2 mutational escape variants and from future animal betacoronavirus spillover events that have pandemic potential. Vaccine development that addresses this vulnerability is urgently needed. Project 2 will support this Program’s overall goal to develop vaccines that will prevent future betaCoV pandemics and SARS-CoV-2 escape variants by designing vaccine immunogens that elicit broadly neutralizing antibodies (bnAb) to provide protective immunity across the betaCoV genus. Structurally conserved neutralizing epitopes exist on betaCoV spike proteins, and we hypothesize that vaccines that elicit broadly protective antibodies to these sites can be developed. In preliminary studies, we have isolated cross-reactive neutralizing antibodies from SARS-CoV-1 or SARS-CoV-2-infected or recovered humans and used structural determination to precisely define their betaCoV bnAb epitopes. Our vaccine design strategy involves using computational and structural- based design techniques to develop immunogens that preferentially present these and additionally identified bnAb epitopes. Each immunogen design will be displayed on the surface of nanoparticles to enhance antigen avidity and antigen trafficking to germinal centers and follicular dendritic cells. We have demonstrated a proof-of-concept for our strategy using a multimerized SARS-CoV-2 receptor binding domain (RBD)- ferritin nanoparticle that induces high titers of antibodies that neutralize diverse human and animal Sarbecoviruses (group 2b) in immunized macaques. In Aim 1, we will isolate new antibodies to define additional bnAb epitopes and establish the full spectrum of regions on the surface of betaCoV S proteins that are capable of inducing bnAbs to animal betaCoVs in groups 2b and 2c. In Aim 2, we will utilize cutting-edge computational immunogen design methods to design broadly neutralizing epitope-focused immunogens. These immunogens have the spike protein fixed in conformations that expose neutralizing epitopes or are spike subunits that are truncated or resurfaced to remove irrelevant, non-neutralizing, or betaCoV strain-specific neutralizing epitopes while retaining broadly neutralizing epitopes. In Aim 3, we will immunize wild-type mice with these novel immunogens and evaluate their ability to induce human betaCoV bnAbs that can protect animals from viral challenge. Project 2 will impact the field by generating cross-reactive neutralizing antibodies that could be translated into therapeutics, elucidating new broadly neutralizing epitopes on the betaCoV spike protein, and defining the design principles for epitope-focused immunogens that elicit protective immunity to betaCoVs.

摘要 - 项目2 动物betacoronavires（betacovs），例如产生SARS-COV-1，MERS和现在的SARS- COV-2代表了对人类健康的重大威胁。疫苗可以提供预先存在的免疫力 未来的人畜共努性冠状病毒。当前有效疫苗对SARS-COV-2的主要局限性是它们 可能只能保护与在 疫苗。那样，世界仍然容易受到SARS-COV-2突变逃生变种 以及未来具有大流行潜力的动物Betacoronavirus Spilover事件。疫苗开发 迫切需要解决此漏洞。项目2将支持该计划开发的总体目标 可以防止将来的Betacov Pandemics和SARS-COV-2逃脱变体的疫苗 设计引起广泛中和抗体（BNAB）提供受保护的疫苗免疫原 Betacov属的免疫力。结构上存在中和表位 在Betacov Spike蛋白上，我们假设引起广泛保护这些抗体的疫苗 站点可以开发。在初步研究中，我们从中分离了交叉反应性中和抗体 SARS-COV-1或SARS-COV-2感染或回收的人，并使用结构确定来精确 定义他们的betacov bnab表位。我们的疫苗设计策略涉及使用计算和结构 - 基于设计的技术来开发优先呈现这些免疫原的免疫原子 确定的BNAB表位。每种免疫原设计将显示在纳米颗粒的表面以增强 抗原的抗原流行和抗原运输到生殖中心和卵泡树突状细胞。我们已经证明了 使用多层化的SARS-COV-2受体结合结构域（RBD）的策略概念证明 - 铁蛋白纳米颗粒会影响中和潜水者和 免疫猕猴中的动物SARBECOVIRASE（第2B组）。在AIM 1中，我们将隔离新抗体以定义 其他BNAB表位，并在Betacov S蛋白表面建立各个区域 能够在第2B和2C组中诱导bnabs对动物betacovs。在AIM 2中，我们将利用尖端 计算免疫原设计方法是设计广泛中和以表位为重点的免疫原。这些 免疫原具有固定在暴露中和表位或尖峰的构象中的尖峰蛋白 被截断或重新浮出的亚基，以消除无关紧要的，非中和或贝塔科夫菌株特异性 中和表位，同时保留广泛中和表位。在AIM 3中，我们将免疫野生型小鼠 借助这些新型免疫原子，并评估了他们诱导人类betacov bnabs的能力，可以保护 病毒挑战的动物。项目2将通过产生交叉反应性中和抗体来影响该领域 可以将其转化为治疗，阐明Betacov Spike上的新的广泛中和表位 蛋白质，并定义引起受保护免疫的以表位为中心免疫原的设计原理 向Betacovs。