Structural biology of antibody:antigen complexes

项目3的总体目标是了解免疫优势的高分辨率结构相关性 并为设计免疫原提供结构基础， 特定的，选择的表位我们的主要假设是，免疫优势的结构贡献， 通过将抗体-抗原复合物的结构与来自抗体-抗原复合物的库的知识相关联， 抗体的来源和导致亲和力成熟的突变序列的重建 抗体从其生殖系前体。项目1中描述的高通量方法可以为我们提供 所需的关于库的信息和关于抗体的亲和力成熟的信息， 疫苗接种与感染我们建议在这里提供相应的三维信息。我们 有以下四个目标。[1)结合的交叉反应性抗体的结构特征是什么 他们的HA抗原表位我们将确定项目中研究的抗体的选定代表的结构 1和2，与相关流感病毒HA复合。我们将开始从标准晶体学 方法，但尽可能快地进行更高通量的cryoEM方法（目标2;另见核心C）。 (2)我们将开发将“客体蛋白”（以流感HA为主要靶标）固定在 二十面体-病毒支架，以产生适合于通过cryoEM进行结构测定的对称阵列。我们将 首先，我们以轮状病毒双层颗粒（DLP）作为支架，外层糖蛋白VP 7作为支架， 安装装置。我们还将测试另一个外层蛋白VP 4作为三聚体安装蛋白。[3)什么 使抗原决定簇成为免疫显性的cryoEM方法提供的检查 系统的和相对公正的一套复合物将使我们能够确定的结构相关的 免疫优势直接。我们将确定与抗体复合的选定HA的结构 代表了项目1中的研究所揭示的典型剧目的整个频谱，并由 项目2. [4)应用于其他病毒抗原。我们将应用目标2中开发的安装策略， 对于其它病毒抗原，库分析和结构解剖的组合可能导致新的

The overall goals of Project 3 are to understand the high-resolution structural correlates of immunodominance and to provide structural foundations for designing immunogens that can focus an immune response on particular, chosen epitopes. Our principal hypothesis is that structural contributions to immunodominance can be revealed by correlating structures of antibody-antigen complexes with knowledge of the repertoire from which the antibody was derived and reconstruction of the mutational sequence that led to the affinity matured antibody from its germline precursor. The high-throughput approaches described in Project 1 can give us the required information about repertoire and about affinity maturation of antibodies denved from the settings of vaccination vs. infection. We propose here to provide the corresponding three-dimensional information. We have the following four Aims. [1) What are the structural characteristics of cross-reactive antibodies bound with their HA epitopes? We will determine structures of selected representatives of the antibodies studied in projects 1 and 2, in complex with the relevant influenza virus HA. We will begin with standard crystallographic approaches, but proceed as rapidly as possible to higher-throughput cryoEM methods (Aim 2; see also Core C). (2) We will develop approaches for mounting "guest proteins" [with influenza HA as the principal target) onto icosahedral-virus scaffolds, to create a symmetric array suitable for structure determination by cryoEM. We will start with the rotavirus double-layer particle (DLP) as our scaffold, and the outer-layer glycoprotein, VP7, as the mounting device.; we will also test the other outer-layer protein, VP4, as a trimeric mounting protein. [3) What makes an epitope immunodominant? The opportunity afforded by the cryoEM approach to examine a systematic and relatively unbiased set of complexes will allow us to determine the structural correlates of immunodominance directly. We will determine structures of a selected HA in complex with antibodies representing the entire spectrum of a typical repertoire as revealed by the studies in Project 1 and mapped by Project 2. [4) Application to other viral antigens. We will apply to the mounting strategies developed in Aim 2 to other viral antigens for which a combination of repertoire analysis and structural dissection might lead to novel