title: Epitope mapping and structural analysis of the anti-Der p 1 monoclonal antibody: insight into therapeutic potential.
abstract: Group 1 allergen from Dermatophagoid pteronyssinus (Der p 1) belongs to the papain-like cysteine protease family and is a major cause of allergic rhinitis and asthma. An anti-Der p 1 monoclonal antibody, mAb W108, was selected and isolated from Der p-specific IgG2b-producing hybridoma clones. Two-dimensional electrophoresis and immunoblotting showed that mAb W108 reacted with four components of Der p extracts with a molecular mass of 35 kDa and pI values varying from 4 to 6; it also reacted with IgE antibodies in the sera of Der p-sensitive patients. In the competitive assay and using azocasein as a substrate, we found that mAb W108 inhibited not only the binding of Der p 1, but also its cysteine protease activity in a dose-dependent manner. The two peptide segments of Der p 1 identified by mAb W108 (aa 151-197 and 286-320) were parts of inter-connecting loops located in the substrate-binding cleft and on the surface of the domain comprising mainly β-sheets. From the predicted interaction between the amino acid sequence in the CDR3 of mAb W108 and Der p 1-binding epitopes, the possible binding sites for mAb W108 to Der p 1 may sterically hinder the IgE epitope and the active site of cysteine protease activity. Administration of mAb W108 in the Der p-sensitized murine model of asthma alleviated allergen-induced airway inflammation and the Th2 cytokine immune response, suggesting its therapeutic potential. These findings can provide new insights into understanding IgE-mediated disease and the design of modified allergen vaccines for future allergen-specific immunotherapy.
authors.affiliation: Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Yu-Chou
authors.initials: YC
authors.lastname: Dai
authors.forename: Woei-Jer
authors.initials: WJ
authors.lastname: Chuang
authors.forename: Kaw-Yan
authors.initials: KY
authors.lastname: Chua
authors.forename: Chi-Chang
authors.initials: CC
authors.lastname: Shieh
authors.forename: Jiu-Yao
authors.initials: JY
authors.lastname: Wang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry* / Q000276:immunology* / Q000494:pharmacology; D039741:Antigens, Dermatophagoides / Q000737:chemistry / Q000276:immunology*; D060829:Arthropod Proteins; D001249:Asthma / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D001666:Binding Sites, Antibody / Q000276:immunology; D003546:Cysteine Endopeptidases; D004195:Disease Models, Animal; D018604:Epitope Mapping; D000939:Epitopes / Q000737:chemistry / Q000276:immunology; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology; D007143:Immunoglobulin Heavy Chains / Q000737:chemistry / Q000276:immunology; D007147:Immunoglobulin Light Chains / Q000737:chemistry / Q000276:immunology; D007249:Inflammation / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010447:Peptide Hydrolases / Q000378:metabolism; D011485:Protein Binding / Q000187:drug effects / Q000276:immunology; D011487:Protein Conformation; D040901:Proteomics; D012137:Respiratory System / Q000276:immunology / Q000378:metabolism / Q000473:pathology
chemical_list: D000911:Antibodies, Monoclonal; D039741:Antigens, Dermatophagoides; D060829:Arthropod Proteins; D000939:Epitopes; D007143:Immunoglobulin Heavy Chains; D007147:Immunoglobulin Light Chains; D007073:Immunoglobulin E; D010447:Peptide Hydrolases; D003546:Cysteine Endopeptidases; C451162:Dermatophagoides pteronyssinus antigen p 1