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: 8703495
• 负责人: James E Crowe
• 金额: $ 39万
• 依托单位: VANDERBILT UNIVERSITY
• 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 2016-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8703495
• 关键词: Adult; Affect; Affinity; Animals; Antibodies; Antibody Formation; Antigens; Area; B-Lymphocytes; Binding; Binding Sites; Biochemical; Biology; Complex; Coupled; Data; Dendritic Cells; Dengue Virus; Development; Disease; Elements; Epithelial Cells; Epitope Mapping; Epitopes; Escape Mutant; Exhibits; Generations; Genes; Genetic; Goals; Grant; Growth; HIV; Head; Human; Immune; Immunity; Individual; Infection; Influenza; Influenza Hemagglutinin; Instruction; Maps; Mediator of activation protein; Mining; Molecular; Molecular Profiling; Monoclonal Antibodies; Mutagenesis; Mutation; Nature; Phylogenetic Analysis; Point Mutation; Polysaccharides; Principal Investigator; Reagent; Reporting; Scientist; Site; Somatic Mutation; Specific qualifier value; Specificity; Structure; Technology; Testing; Time; Vaccination; Vaccine Antigen; Vaccines; Viral; Virus; Work; alpha helix; base; cross reactivity; design; human monoclonal antibodies; human subject; immunogenic; in vivo; influenzavirus; interest; mutant; neutralizing monoclonal antibodies; novel; programs; receptor; receptor binding; response; sialic acid receptor; stem

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. 项目主任/首席研究员（最后、第一、中间）：G A R C I A - S A S T R E , Adolfo 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中令人兴奋的最新进展 该项目的目标是确定具有广泛 erbss 反应性的人类单克隆抗体的分子和结构基础 对流感HA的反应；由于广泛交叉反应的抗体所识别的表位序列和结构是 定义后，我们将能够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 Gonserv 区域的人类抗体库；规范茎域 表位、长α螺旋茎结构域和球状头结构域。假设出乎意料的是，有 流感HA中至少有三个免疫原性结构域，它们保留了高度保守的结构特征，并且大多数 成年健康受试者确实拥有与 HA 上这些保守位点发生交叉反应的循环 B 细胞克隆。这些 然而，结构域很复杂，并且相对难以接近——对于传统的 Ab 结构，我们已经开发出了稳健的 分离人类单克隆抗体的技术揭示了侵蚀反应性 B 细胞相对常见的性质，以及 不同亚型流感病毒分泌抗体广泛交叉反应的遗传和结构基础。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^尤其是异常高的 体细胞点突变和体细胞插入的水平。这个高度互动的项目将进行协作工作 与项目 1 一起确定 mAb-HA 共晶结构。项目4研究病毒逃逸突变病毒的生物学； 项目 5 检查突变体对 DC 的影响，并将使用聚糖阵列核心来研究逃逸过程中的糖基化 位点和 Animal Core 以确定 vivQ 中抗体的效力。对此类 Abs 及其识别位点的研究 他们将为基于异亚型基本原理的通用流感疫苗的合理设计提供信息 免疫;茎结构域之所以令人感兴趣，是因为已鉴定出具有高度侵蚀反应性的抗体，该抗体可识别 该地区的保护区。然而，迄今为止发现的稀有 Abs 并不同时具备第 1 组和第 2 组特异性， 在初步的 datBi 中，我们表明分离此类 Abs 是可能的。使用这些不寻常的试剂，我们将定义 组决定因素或保守元素的基础：通过将新 Abs 的大组相互作用映射到： 茎；区域。我们还将寻求从识别两种主要抗体茎的人类受试者中分离出新的人类抗体。 HA 抗原性基因组。头域得到了更好的研究，但是只有罕见的 Abs：表现出交叉反应性 抗原性不同的HA。通过对来自季节性和实验性免疫对象的 B 细胞进行大规模科学筛选 疫苗中，我们已经鉴定出交叉反应性抗体，其能够识别多种亚型的 HA 的头域。 流感。通过使用生化和生物学研究进行表位作图，并结合确定共晶的研究 结构，我们将确定交叉反应的结构基础。 RJELEVANGE（参见说明）： 抗体是预防流感引起的疾病的主要介质 感染或疫苗接种，但流感病毒表现出很大的多样性，需要每年 疫苗接种。然而，一些不寻常的人类抗体可以对抗多种流感病毒， 建议；a！通用疫苗或许是可能的。拟议的研究将确定潜在的 通用疫苗抗原的成分。