Epitope focusing using structure-based immunogen design approaches

项目摘要/摘要 自新型严重急性呼吸系统综合症病毒2型(SARS-CoV-2)冠状病毒出现以来， 需要更好的框架来快速开发疫苗以应对新出现的病毒威胁，包括其他 很明显，冠状病毒具有潜在的大流行担忧。一种方法是开发一种免疫原设计 利用病毒表面糖蛋白和其宿主细胞之间通常保守的界面的平台 受体(S)。对于SARS-CoV-2，所激发的抗体将针对其“尖峰”糖蛋白之间的相互作用 和人类血管紧张素转换酶2(ACE-2)受体。其他冠状病毒，如SARS-CoV-1和 常见的引起感冒的NL63也使用ACE-2，从而干扰这种保守的相互作用的抗体 也可能预防未来也使用这种受体的新型冠状病毒。这项拟议工作的目标是 就是利用结构导向、合理设计的新型免疫原将免疫应答集中到ACE-2上 SARS-CoV-2的受体结合界面。这可能为免疫原设计提供一个可推广的框架 未来可以迅速用于对抗新出现的病毒的战略。我将使用以下两个 设计方法：1)我将使用结构上与SARS-CoV-2同源的分子支架 受体结合域(RBD)，并用来自SARS的ACE-2受体结合基序(RBM)重新浮出水面- CoV-2。因此，抗原性不同的支架将统一呈现保守的SARS-CoV-2 RBM 并将免疫反应集中在保守的界面上。2)我会用高糖基化的面膜 SARS-CoV-2 RBD上的免疫优势、非保护性表位引导对SARS-CoV-2的免疫应答 SARS-CoV-2 RBM。对于这两种方法，我将分析引发的免疫反应，以确定 对SARS-CoV-2 RBM进行免疫聚焦，获得中和图谱，并对其进行结构鉴定 所选的激发抗体。总而言之，这些数据将提供对遮罩和重新铺设如何 决定性地将免疫反应导向保守的病毒表位。而我用SARS-CoV-2作为模型 病毒，这可能为未来的病毒病原体提供一个疫苗设计框架，有可能快速 部署。

Project Summary/Abstract Since the emergence of the novel severe acute respiratory syndrome virus 2 (SARS-CoV-2) coronavirus, the need for better frameworks to rapidly develop vaccines in response to emerging viral threats, including other coronaviruses of potential pandemic concern, is clear. One approach is to develop an immunogen design platform that leverages the often-conserved interface between viral surface glycoproteins and their host cellular receptor(s). For SARS-CoV-2, elicited antibodies would target the interaction between its “spike” glycoprotein and the human angiotensin-converting enzyme 2 (ACE-2) receptor. Other coronaviruses like SARS-CoV-1 and the common cold-causing NL63 also use ACE-2, thus antibodies that interfere with this conserved interaction might also protect against future novel coronaviruses that also use this receptor. The goal of this proposed work is to use structure-guided, rational design of novel immunogens to focus the immune response to the ACE-2 receptor binding interface of SARS-CoV-2. This may provide a generalizable framework of immunogen design strategies that can be rapidly used to combat novel emerging viruses in the future. I will use the following two design approaches: 1) I will use molecular scaffolds that are structurally homologous to the SARS-CoV-2 receptor binding domain (RBD) and “resurface” them with the ACE-2 receptor binding motif (RBM) from SARS- CoV-2. As a result, the antigenically distinct scaffolds will uniformly present the conserved SARS-CoV-2 RBM and will focus the immune response to the conserved interface. 2) I will use hyperglycosylation to mask immunodominant, non-protective epitopes on the SARS-CoV-2 RBD to direct the immune response to the SARS-CoV-2 RBM. For both approaches, I will analyze the elicited immune response to determine the extent of immune focusing to the SARS-CoV-2 RBM, obtain neutralization profiles and structurally characterize down- selected elicited antibodies. Collectively, these data will provide insight into how masking and resurfacing can determinatively direct the immune response to a conserved viral epitope. While I use SARS-CoV-2 as a model virus, this could provide a vaccine design framework for future viral pathogens with the potential for rapid deployment.