Antigenic determinants of asthma-associated allergens for design of immunotherapy

用于免疫治疗设计的哮喘相关过敏原的抗原决定簇

• 批准号: 7726352
• 负责人: MARTIN D. CHAPMAN
• 金额: $ 35.18万
• 依托单位: INDOOR BIOTECHNOLOGIES
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-25 至 2013-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7726352
• 关键词: Accident and Emergency department; Admission activity; Affect; Allergen Immunotherapy; Allergens; Allergic; Allergic Reaction; Am 80; Amino Acids; Antibodies; Antibody Binding Sites; Antibody Formation; Area; Aspartic Endopeptidases; Asthma; Basophils; Binding; Biological Assay; Breathing; Cells; Child; Complex; Crystallization; Crystallography; Cysteine Protease; Dermatophagoides farinae antigen f 1; Dermatophagoides pteronyssinus; Dermatophagoides pteronyssinus antigen p 1; Development; Dictyoptera; Dimerization; Disease; Dose; Environment; Enzyme-Linked Immunosorbent Assay; Epitopes; Felis catus; Goals; Health; High Prevalence; Homologous Gene; House Dust Mite Allergens; Hypersensitivity; IgE; Immunoglobulin Fragments; Immunoglobulin G; Immunologics; Immunotherapy; Individual; Inflammatory Response; Lung; Lung Inflammation; Maps; Mediator of activation protein; Mites; Molecular; Monoclonal Antibodies; Nature; Papain; Patients; Pepsin A; Phage Display; Pichia; Process; Property; Recombinants; Reporting; Risk Factors; Site-Directed Mutagenesis; Structure; Surface; T-Cell Proliferation; T-Lymphocyte; Technology; Testing; Th2 Cells; Time; Vaccine Design; Vaccines; abstracting; allergen Bla g 2; base; cockroach allergen; cross reactivity; crosslink; cytokine; design; inner city; insight; mast cell; mutant; novel vaccines; public health relevance; pyroglyphid

DESCRIPTION (provided by applicant): Antigenic determinants of asthma-associated allergens for design of immunotherapy Project Summary/Abstract Allergic reactions to cockroach and dust mite are important health problems in the U.S. affecting up to 83% of asthmatic children in inner city areas and are a risk factor for emergency room admission with asthma. The main cockroach species in the U.S., Blattella germanica, produces Bla g 2 which induces sensitization at exposure levels 10-100 times lower than cat and mite allergens, and has the highest prevalence of sensitization among cockroach allergens (40-70%). Der p 1 and Der f 1 are cysteine proteases produced by the dust mites Dermatophagoides pteronyssinus and D. farinae, respectively. IgE sensitization to these Group 1 allergens is >80% among mite allergic patients. Proteolytic activity of Der p 1 may enhance IgE antibody production and contribute to lung inflammation in asthma but Bla g 2 is an inactive aspartic protease- homolog. The main goal of this project is to investigate the antigenic structure of proteolytic (mite Group 1) and non-proteolytic (Bla g 2) allergens associated with asthma. Allergens will be co-crystallized with monoclonal antibodies, and the key amino acids involved in antibody (IgE and mAb) binding will be identified. Alternatively, identification of IgE antibody binding epitopes will be performed by phage display technology. The specific aims are: 1) mapping of antigenic determinants in Bla g 2 by crystallography; 2) mapping of antigenic determinants of Group 1 mite allergens by crystallography and analysis of the structural basis for the cross-reactivity between Der p 1 and Der f 1; and 3) localization of the key amino acids involved in the antibody binding epitopes by site-directed mutagenesis studies and identification of hypoallergenic mutants with T cell reactivity that could be used for immunotherapy. IgE antibody binding to the epitope mutants will be analyzed by ELISA, multiplex array technology and cell mediator release assays. Mutants will be compared to select hypoallergenic forms for the design of vaccines for immunotherapy of mite and cockroach allergy. PUBLIC HEALTH RELEVANCE: Cockroach and mite allergy is associated with the development of asthma, which affects 17 million people in the U.S. The antigenic determinants of Bla g 2 and Group 1 mite allergens will be identified to elucidate the importance of the intrinsic properties of these allergens on allergic disease. Hypoallergenic mutants will be produced and tested for IgE antibody binding and T cell proliferation, and the information obtained will facilitate a rational design of allergy vaccines.

描述（由申请人提供）：用于免疫疗法设计的哮喘相关过敏原的抗原决定因素项目摘要/摘要在美国，对蟑螂和尘螨的过敏反应是重要的健康问题，影响着内城区高达 83% 的哮喘儿童，也是因哮喘入急诊室的危险因素。美国的主要蟑螂种类德国小蠊产生 Bla g 2，其在比猫和螨过敏原低 10-100 倍的暴露水平下诱导致敏，并且在蟑螂过敏原中具有最高的致敏率（40-70%）。 Der p 1 和 Der f 1 是分别由尘螨 Dermatophagoides pteronyssinus 和 D. farinae 产生的半胱氨酸蛋白酶。在螨过敏患者中，IgE 对这些 1 类过敏原的过敏率 >80%。 Der p 1 的蛋白水解活性可能会增强 IgE 抗体的产生并导致哮喘中的肺部炎症，但 Bla g 2 是一种无活性的天冬氨酸蛋白酶同系物。该项目的主要目标是研究与哮喘相关的蛋白水解（螨组 1）和非蛋白水解（Bla g 2）过敏原的抗原结构。过敏原将与单克隆抗体共结晶，并鉴定出参与抗体（IgE 和 mAb）结合的关键氨基酸。或者，IgE 抗体结合表位的鉴定将通过噬菌体展示技术进行。具体目标是：1）通过晶体学绘制 Bla g 2 中的抗原决定簇图谱； 2)通过晶体学绘制第1组螨过敏原的抗原决定簇并分析Der p 1和Der f 1之间交叉反应性的结构基础； 3) 通过定点诱变研究定位参与抗体结合表位的关键氨基酸，并鉴定具有可用于免疫治疗的 T 细胞反应性的低变应原性突变体。 IgE 抗体与表位突变体的结合将通过 ELISA、多重阵列技术和细胞介质释放测定进行分析。将突变体与选定的低过敏性形式进行比较，以设计用于螨虫和蟑螂过敏免疫治疗的疫苗。公共卫生相关性：蟑螂和螨虫过敏与哮喘的发生有关，哮喘影响美国 1700 万人。将鉴定 Bla g 2 和 1 类螨虫过敏原的抗原决定簇，以阐明这些过敏原的内在特性对过敏性疾病的重要性。将生产低过敏性突变体并测试 IgE 抗体结合和 T 细胞增殖，获得的信息将有助于过敏疫苗的合理设计。