Allergy to Bovine â–Lactoglobulin: Specificity of Human IgE Using Cyanogen Bromide–Derived Peptides

Abstract

Background: Bovine β–Lactoglobulin (Blg) is a major allergen involved in allergy to cow's milk proteins. Hydrolyzing Blg did not totally suppress its allergenicity; moreover its immunoreactivity may be increased. The aim of this work was to evaluate the specificity of serum IgE to different fragments of Blg in a group of 19 individuals allergic to cow's milk. Methods: This study was performed using both direct and competitive inhibition ELISA involving immobilized native protein or peptides derived from Blg cyanogen bromide cleavage. Results: Analyses of responses to each peptide revealed a large number of epitopes recognized by specific IgE of human allergic sera. However, there were differences in the specific determinants recognized, depending on the serum. Generally, peptides (25–107) and (108–145) retained substantial proportions of the immunoreactivity of the whole protein. Two other peptides, i.e. (8–24) and (146–162), were less recognized but were not inert. Conclusion: The main conclusion is that many epitopes were identified all along the Blg sequence by specific anti–Blg IgE from allergic humans.