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: 8132855
• 负责人: MARTIN D. CHAPMAN
• 金额: $ 45.33万
• 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/8132855
• 关键词: Accident and Emergency department; Admission activity; Affect; Allergen Immunotherapy; Allergens; Allergic; Allergic Disease; 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; 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; 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(申请人提供)：设计免疫治疗项目的哮喘相关过敏原的抗原决定因素摘要/摘要蟑螂和尘螨的过敏反应在美国市中心地区影响高达83%的哮喘儿童的重要健康问题，也是哮喘急诊室入院的危险因素。德国小蠊是美国的主要蟑螂品种，其产生的Bla g 2致敏水平比猫和螨变应原低10-100倍，是蟑螂变应原中致敏程度最高的(40%-70%)。Der-p1和Der-f-1分别是由屋尘螨和粉尘螨产生的半胱氨酸蛋白酶。在尘螨过敏患者中，IgE对这些第1类变应原的敏感率为80%。Delp1的蛋白分解活性可能促进IgE抗体的产生，并促进哮喘的肺部炎症，而Blag2是一种无活性的天冬氨酸蛋白酶同源物。该项目的主要目的是研究与哮喘相关的蛋白水解性变应原(MITE Group 1)和非蛋白水解性变应原(Bla G 2)的抗原结构。变应原将与单抗共结晶，并将识别参与抗体结合的关键氨基酸(IgE和mAb)。或者，将通过噬菌体展示技术鉴定IgE抗体结合表位。其具体目的是：1)通过结晶学定位Bla-g2中的抗原决定簇；2)通过结晶学定位1组尘螨变应原的抗原决定簇，并分析Der p 1和Der f 1之间交叉反应的结构基础；3)通过定点突变研究定位抗体结合表位中的关键氨基酸，并鉴定可用于免疫治疗的具有T细胞反应性的低变应原突变体。结合表位突变体的免疫球蛋白抗体将通过酶联免疫吸附试验、多重阵列技术和细胞介体释放试验进行分析。将对突变体进行比较，以选择低过敏性形式，以设计用于螨类和蟑螂过敏免疫治疗的疫苗。与公共卫生相关：蟑螂和尘螨过敏与哮喘的发生有关，在美国有1700万人受到哮喘的影响。我们将确定Bla g 2和1组尘螨变应原的抗原决定因素，以阐明这些过敏原的内在特性在过敏性疾病中的重要性。将产生低过敏性突变体，并对IgE抗体结合和T细胞增殖进行测试，所获得的信息将有助于合理设计过敏疫苗。