Molecular Determinants of Cross-Reactive Antibody Response to Influenza in Humans

人类流感交叉反应抗体反应的分子决定因素

• 批准号: 9269445
• 负责人: James E Crowe
• 金额: $ 2.01万
• 依托单位: VANDERBILT UNIVERSITY MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-15 至 2017-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9269445
• 关键词: Molecular; Determinants; Cross; Reactive; Antibody

Project 2. Program CJirector/Principal Investigator (Last, First. Middle): G A R C I A - S A S T R E , A d o l f o PROJECT SU^/)^MRY (See instructions): Work in Project 2 will explore exciting recent developments in the study of cross-reactive immunity to influenza viruses.The goal of this project is to determine the molecular and structural basis for broadly erbss-reactive human mAb responses to influenza HAs; As the epitope sequences and structures reccjgnized by broadly cross-reactive Abs are defined, we will be better able to rationally design broadly protective immuriogens. The work seeks to investigate the repertoire of human Abs recognizing three principal Gonserved regions of the HA molecule; a canonical stalk domain epitope, the long alpha-helix stalkdomain, and the globular head domain. The hypothesis is that, unexpectedly, there are at least three immunogenic domains in influenza HA that retain highly conserved structural features and that most adult healthy subjects do possess circulating cross-reactive B cell clones to these conserved sites on HA. These domains are complex, however, and relatively inaccessible-for conventional Ab structures, w e have developed robust technologies for isolating human mAbs that reveal the relatively frequent nature of eross-reactive B ceils, and the genetic'arid structural basis for broad cross-reactivity of the secreted Abs for influenza viruses of diverse subtypes. We hypothesize that such cross-reactivity is driven by unusual features in the Ab repertoire^ especially an exceptionally high levefof somatic point mutations and somatic insertions. This highly interactive project will engage in collaborative work with Project 1 to determine mAb-HA co-crystal structures. Project 4 to study the biology of viral escape mutant viruses,; Project 5 to examine the effect of mutants on DCs, and will use the Glycan Array core to study glycosyiation in escape sites and the Animal Core to determine in vivQ potency of antibodies. Studies of such Abs and the sites recognized by them will inform the rational design of universalinfluenza vaccines based on the underlying principles of heterosubtypjc immunity; The stalk domain is of interest because highly eross-reactive Ab have been identified that recognized a conserved region in this area. However, the rare Abs identified to date do not possess both group 1 and 2 specificities, , In preliminary datBi we show that it is possible to isolate such Abs. Using these unusual reagents, we will define the basis for the group determinants or conserved elelmentS: by mapping the interaction of large panels of new Abs to the: stalk;region. We also will seek to isolate novel human Abs from human subjects that recognize the stalks of both major HA antigenic groijps. The head domain is better studied, however there are only rare Abs:that exhibit cross-reactiyity for ahtigenically distinct HAs. By large-scale sci-efening of B cells from subjectis immunized with seasonal and experimental vaccines, we have identified cross-reactive Abs that i-ecdgnize the head domain of HAs of multiple subtypes of influenza. By epitope mapping using biochemical arid biologic studies, coupled with studies to determine co-crystal stuctures, we will determine the structural basis for cross reactivity. RJELEVANGE (See instructions): Antibodies are the priricipal mediators of protection.induced against disease due to influenza following infection or vaccination, but influenza viruses exhibit a large amount of diversity, necessitating yearly vaccination. Some unusual human antibodies, however, react against a wide variety of influenza viruses, suggesting that;a! universal vaccine might be possible. The proposed studies will identify potential components of a universal vaccine antigen.

项目2.项目负责人/主要研究者（最后，第一。中）：G A R C I A - S A S T R E，A d o l f o 项目SU^/）^MRY（参见说明）： 项目2的工作将探索流感交叉反应免疫研究的最新进展 本项目的目标是确定广泛的erbss反应性人单克隆抗体的分子和结构基础， 由于广泛交叉反应性抗体识别的表位序列和结构是特异性的， 从而更好地合理设计具有广泛保护性的免疫原。这项工作旨在调查 识别HA分子的三个主要保守区域的人Ab库;典型的茎域 表位、长α-螺旋茎域和球状头域。假设是，出乎意料的是， 是流感HA中的至少三个免疫原性结构域，其保留高度保守的结构特征， 成年健康受试者确实具有与HA上的这些保守位点交叉反应的循环B细胞克隆。这些 然而，结构域是复杂的，并且相对难以实现-对于传统的Ab结构，我们已经开发了鲁棒的 用于分离人单克隆抗体的技术揭示了细胞反应性B细胞的相对频繁的性质， 基因和结构基础的广泛交叉反应性的分泌抗体的流感病毒的不同亚型。我们 假设这种交叉反应性是由Ab库中的不寻常特征驱动的，特别是异常高的抗体库。 体细胞点突变和体细胞插入。这个高度互动的项目将从事协作工作 与项目1一起确定mAb-HA共晶体结构。项目4：研究病毒逃逸突变病毒的生物学; 项目5研究突变体对DC的影响，并将使用聚糖阵列核心研究逃逸中的糖基化 位点和动物核心以确定抗体的体内效力。对这些抗体的研究以及 它们将为基于异质亚型基本原理的通用流感疫苗的合理设计提供信息。 茎域是令人感兴趣的，因为已经鉴定出高度侵蚀反应性的Ab，其识别免疫原性。 该地区的保守区。然而，迄今为止鉴定的罕见Ab不具有组1和组2特异性， 在初步的datBi，我们表明，它是可能的，以隔离这样的抗体。使用这些不寻常的试剂，我们将定义 组决定簇或保守元素的基础：通过将大量新Ab的相互作用映射到： 茎;区域我们还将寻求从人类受试者中分离出新的人类抗体，这些受试者识别两种主要的 HA抗原组。头部结构域得到了更好的研究，但是只有罕见的Ab：表现出与 遗传上不同的HA。通过对季节性和实验性免疫受试者的B细胞进行大规模科学研究， 在疫苗中，我们已经鉴定出交叉反应性抗体，其可识别多种亚型的HA的头部结构域， 流感。通过使用生物化学和生物学研究的表位作图，再加上确定共晶的研究 结构，我们将确定交叉反应性的结构基础。 RJELEVANGE（参见说明）： 抗体是预防流感引起的疾病的主要介质， 感染或接种疫苗，但流感病毒表现出大量的多样性，需要每年 预防针然而，一些不寻常的人类抗体对多种流感病毒起反应， 这意味着：A！通用疫苗是可能的。拟议的研究将确定潜在的 通用疫苗抗原的组分。