title: C8/119S mutation of major mite allergen Derf-2 leads to degenerate secondary structure and molecular polymerization and induces potent and exclusive Th1 cell differentiation.
abstract: Hyposensitization therapy for atopic diseases has been conducted for decades but suffered from many problems including anaphylactic reactions. We previously developed a mutant protein of the major mite allergen Derf-2, C8/119S, which showed reduced binding to IgE. The C8/119S mutant was shown to exhibit more efficient hyposensitizing effect than Derf-2 in the animal model of allergic bronchial asthma. In the present study, we indicate that C8/119S exhibits markedly augmented immunogenicity for the proliferation of Derf-2-specific human T cells and T cell clones irrespective of the epitope specificity as compared with Derf-2. Furthermore, C8/119S has induced potent and almost exclusive differentiation of Th1 cells from the peripheral blood of atopic patients in vitro. Neither Ag dosage effect nor absence of B cell-mediated Ag presentation could fully account for these effects. C8/119S has been indicated to lose the characteristic beta-barrel structure as judged by circular dichroism spectroscopic analysis and to polymerize solubly in physiological condition. Heating of Derf-2 also caused less stable molecular aggregation, but it hardly affected the secondary structure and failed to induce such a polarity toward the Th1 cell differentiation. These results have indicated that the degenerate secondary structure of C8/119S leading to stable molecular polymerization is primarily responsible for the marked increase in T cell-immunogenicity and the induction of exclusive Th1 cell differentiation in atopic patients. It has been suggested strongly that the recombinant C8/119S protein can provide an effective Ag with the least risk of anaphylaxis for allergen immunotherapy against house dust mite in human.
authors.affiliation: Department of Immunology and Cell Biology, Graduate School of Medicine, and Research Institute for Food Science, Kyoto University, Kyoto, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Korematsu
authors.forename: Y
authors.initials: Y
authors.lastname: Tanaka
authors.forename: S
authors.initials: S
authors.lastname: Hosoi
authors.forename: S
authors.initials: S
authors.lastname: Koyanagi
authors.forename: T
authors.initials: T
authors.lastname: Yokota
authors.forename: B
authors.initials: B
authors.lastname: Mikami
authors.forename: N
authors.initials: N
authors.lastname: Minato
mesh_terms: D000276:Adjuvants, Immunologic / Q000235:genetics; D000485:Allergens / Q000737:chemistry / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D019943:Amino Acid Substitution / Q000235:genetics / Q000276:immunology*; D000818:Animals; D017951:Antigen Presentation / Q000235:genetics; D039741:Antigens, Dermatophagoides; D001402:B-Lymphocytes / Q000276:immunology; D002454:Cell Differentiation / Q000235:genetics / Q000276:immunology; D002999:Clone Cells; D003545:Cysteine / Q000235:genetics; D004306:Dose-Response Relationship, Immunologic; D018984:Epitopes, T-Lymphocyte / Q000276:immunology; D006023:Glycoproteins / Q000737:chemistry* / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000097:blood / Q000276:immunology; D008213:Lymphocyte Activation / Q000235:genetics; D008925:Mites / Q000235:genetics / Q000276:immunology*; D016297:Mutagenesis, Site-Directed; D017433:Protein Structure, Secondary; D012694:Serine / Q000235:genetics; D018417:Th1 Cells / Q000166:cytology* / Q000276:immunology*
chemical_list: D000276:Adjuvants, Immunologic; D000485:Allergens; D039741:Antigens, Dermatophagoides; D018984:Epitopes, T-Lymphocyte; D006023:Glycoproteins; D012694:Serine; D003545:Cysteine