%0 Journal Article
%T Targeting a Cross-Reactive Gly m 5 Soy Peptide as Responsible for Hypersensitivity Reactions in a Milk Allergy Mouse Model
%A Renata Curciarello
%A Paola L. Smaldini
%A Angela M. Candreva
%A Virginia Gonz¨¢lez
%A Gustavo Parisi
%A Ana Cauerhff
%A Ivana Barrios
%A Luis Bruno Blanch
%A Carlos A. Fossati
%A Silvana Petruccelli
%A Guillermo H. Docena
%J PLOS ONE
%D 2014
%I Public Library of Science (PLoS)
%R 10.1371/journal.pone.0082341
%X Background Cross-reactivity between soybean allergens and bovine caseins has been previously reported. In this study we aimed to map epitopes of the major soybean allergen Gly m 5 that are co-recognized by casein specific antibodies, and to identify a peptide responsible for the cross-reactivity. Methods Cow's milk protein (CMP)-specific antibodies were used in different immunoassays (immunoblotting, ELISA, ELISA inhibition test) to evaluate the in vitro recognition of soybean proteins (SP). Recombinant Gly m 5 (¦Á), a truncated fragment containing the C-terminal domain (¦Á-T) and peptides of ¦Á-T were obtained and epitope mapping was performed with an overlapping peptide assay. Bioinformatics tools were used for epitope prediction by sequence alignment, and for modelling the cross-recognized soy proteins and peptides. The binding of SP to a monoclonal antibody was studied by surface Plasmon resonance (SPR). Finally, the in vivo cross-recognition of SP was assessed in a mouse model of milk allergy. Results Both ¦Á and ¦Á-T reacted with the different CMP-specific antibodies. ¦Á-T contains IgG and IgE epitopes in several peptides, particularly in the peptide named PA. Besides, we found similar values of association and dissociation constants between the ¦Á-casein specific mAb and the different milk and soy components. The food allergy mouse model showed that SP and PA contain the cross-reactive B and T epitopes, which triggered hypersensitivity reactions and a Th2-mediated response on CMP-sensitized mice. Conclusions Gly m 5 is a cross-reactive soy allergen and the ¦Á-T portion of the molecule contains IgG and IgE immunodominant epitopes, confined to PA, a region with enough conformation to be bound by antibodies. These findings contribute to explain the intolerance to SP observed in IgE-mediated CMA patients, primarily not sensitised to SP, as well as it sets the basis to propose a mucosal immunotherapy for milk allergy using this soy peptide.
%U http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0082341