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因素。

• 批准号: 9067975
• 负责人: MARTIN D. CHAPMAN
• 金额: $ 69.78万
• 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 2020-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9067975
• 关键词: Accident and Emergency department; Accounting; Admission activity; Affect; Allergens; Allergic; Allergic Disease; Allergic Reaction; Amino Acids; Antibodies; Antibody Formation; Antibody Repertoire; Antibody Response; Asthma; Award; B-Lymphocyte Epitopes; B-Lymphocytes; Binding; Biological Assay; Blood; Caspase; Cells; Characteristics; Child; Clinical Research; Complex; Crystallization; Data; Data Set; Databases; Dermatophagoides farinae antigen f 1; Dermatophagoides pteronyssinus; Dermatophagoides pteronyssinus antigen p 1; Dermatophagoides pteronyssinus antigen p 2; Development; Dictyoptera; Engineering; Enzyme-Linked Immunosorbent Assay; Epitopes; Escherichia coli; Funding; Goals; Grant; Health; Homologous Gene; Human; Hypersensitivity; IgE; Immune; Immune response; Immune system; Immunoglobulin G; Immunotherapeutic agent; Immunotherapy; Lead; Libraries; Lung Inflammation; Maps; Mediator of activation protein; Mites; Molecular; Mus; Patients; Phage Display; Phase; Pichia; Prevalence; Production; Property; Pyroglyphidae; Recombinants; Reporting; Risk Factors; Site-Directed Mutagenesis; Specificity; Structure; T-Cell Activation; T-Cell Proliferation; T-Lymphocyte; Technology; Testing; Time; Toll-like receptors; Vaccine Design; Vaccines; Variant; X-Ray Crystallography; asthmatic; asthmatic patient; base; combinatorial; cytokine; design; immunoreactivity; impaired capacity; improved; indoor allergen; innovation; lipopolysaccharide-binding protein; mutant; pyroglyphid; response; screening; three dimensional structure; tool

 DESCRIPTION (provided by applicant): Allergic reactions to house dust mite are an important health problem worldwide, affecting up to 85% of asthmatic children, and are a risk factor for emergency room admission with asthma. Group 1 and 2 mite allergens account for more than 50% of total house dust mite specific IgE reactivity in mite allergic patients. Mite allergens Der p 1 and Der f 1 are cysteine proteases produced by the dust mites Dermatophagoides pteronyssinus and D. farinae, respectively. Proteolytic activity of Der p 1 may enhance IgE antibody production and contribute to lung inflammation in asthma. In contrast, group 2 mite allergens are lipopolysaccharide binding proteins. Der p 2 has been reported to mimic a human structural-homolog that activates the innate immune system through toll like receptors. Despite these important molecular differences between proteolytic group 1 and non-proteolytic group 2, a high IgE prevalence of 83% to allergens from both groups has been observed in mite allergic patients in the US. The main goal of this project is to investigate the antigenic structure of both groups of mite allergens, for the design of immunotherapy. Allergens will be co-crystallized with IgE antibody constructs selected by phage display technology. The key amino acids involved in IgE antibody binding will be identified and modified. The specific aims are: 1) selection of IgE antibody constructs (scFv) from combinatorial libraries made from blood of mite allergic patients using phage display technology; 2) mapping of antigenic determinants on groups 1 and 2 dust mite allergens by X-ray crystallography and analysis of IgE antibody binding epitopes; and 3) site-directed mutagenesis of IgE antibody epitopes for expression of hypoallergenic mutants with T cell reactivity as candidates for immunotherapy. An analysis of the association between mite allergen-specific IgE antibodies from the human repertoire and the epitopes recognized by these IgE antibodies will be performed with the information obtained in the first two aims. Aim #2 will generate experimental data sets of three-dimensional structures of B-cell epitopes that are missing in current databases used for developing tools for B cell epitope prediction. Most importantly, this project will define IgE antibody responses to mite allergens and will provide the structural basis for rational design of hypoallergens. In Aim #3, IgE antibody binding to the epitope mutants will be analyzed by ELISA, multiplex array technology and cell mediator release assays, and T cell reactivity will be evaluated. Mutants will be compared and hypoallergenic forms will be selected for the design of vaccines for immunotherapy of mite allergy.

 描述（由适用提供）：对房屋尘螨的过敏反应是全球重要的健康问题，影响了多达85％的哮喘儿童，并且是哮喘急诊室入院的危险因素。第1组和第2组螨过敏原占螨虫过敏患者中特定于房屋尘螨特定的IgE反应性的50％以上。螨虫过敏原p 1和der f 1分别是尘螨皮肤pteronyssinys和D. farinae产生的半胱氨酸蛋白酶。 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感染。相反，第2组螨过敏原是脂多糖结合蛋白。据报道，der p 2可以模仿人类的结构同源物，该结构同源物通过像接收器一样的收费来激活先天免疫系统。尽管蛋白水解1和非蛋白水解组2之间存在这些重要的分子差异，但在美国的螨虫过敏患者中，两组的过敏原的高IgE患病率均为83％。该项目的主要目的是研究两组螨过敏原的抗原结构，以设计免疫疗法。过敏原将与通过噬菌体显示技术选择的IgE抗体构建体共结晶。将鉴定和修饰参与IgE抗体结合的关键氨基酸。具体目的是：1）使用噬菌体显示技术从螨虫过敏患者血液制成的组合文库中选择IgE抗体构建体（SCFV）； 2）通过X射线晶体学和IgE抗体结合表位分析在第1组和2组尘螨过敏原上绘制抗原确定剂； 3）IgE抗体表达的位置定向诱变，用于表达具有T细胞反应性的低过敏性突变体作为免疫疗法的候选者。将对在前两个目的中获得的信息进行分析，分析来自人类曲目的螨虫特异性IgE抗体与这些IgE抗体所识别的表位之间的关联。 AIM＃2将生成B细胞表位的三维结构的实验数据集，这些数据集中在当前数据库中缺少用于开发B细胞表位预测工具的数据库。最重要的是，该项目将定义对螨过敏原的IgE抗体反应，并为低过敏原的合理设计提供结构基础。在AIM＃3中，将通过ELISA，多个阵列技术和细胞介质释放测定法分析IgE抗体与表位突变体的结合，并评估T细胞反应性。将比较突变体，并选择低过敏性形式以设计疫苗以进行螨过敏的免疫疗法。