Evaluation of Reduced Allergenicity of Deamidated Giiadin in a Mouse Model of Wheat-Gliadin Allergy Using an Antibody Prepared by a Peptide Containing Three Epitopes

摘要

Giiadin is the principal allergen of wheat-dependent exercise-induced anaphylaxis (WDEIA). The primary structure of IgE-binding epitopes in wheat giiadin includes tandem sequencing sites of glutamine residues. Therefore, deamidation would be an effective approach to reduce the allergenicity of wheat proteins. In our previous study, we deamidated wheat giiadin without causing peptide-bond hydrolysis or polymerization by use of carboxylated cation-exchange resins, and we found that the deamidated giiadin scarcely reacted with the sera of patients radioallergosorbent test (RAST)-positive to wheat. In this study, we examined the allergenicity of deamidated giiadin in a mouse model of wheat-gliadin allergy. Oral administration of deamidated giiadin to gliadin-sensitized mice suppressed enhancement in intestinal permeability, serum allergen level, serum allergen-specific IgE level, mast-cell-surface expression of FceRI, and serum and intestinal histamine levels. Our results indicate that giiadin deamidated with no peptide-bond hydrolysis by cation-exchange resins has low allergenicity even under in vivo conditions.