ARS | Publication request: ROASTING MAY ALTER THE IGE BINDING EPITOPES AND SENSITIZING ABILITY OF PEANUT ALLERGENS

Submitted to: American Academy of Allergy Asthma and Immunology
Publication Type: Abstract Only
Publication Acceptance Date: January 1, 2004
Publication Date: April 1, 2004
Citation: Maleki, S.J., Galeano, M.J., Champagne, E.T., Shinohara, K. 2004. Roasting may alter the ige binding epitopes and sensitizing ability of peanut allergens. American Academy of Allergy Asthma and Immunology. 113:515

Technical Abstract: Little is known about why certain foods are allergenic. Previous research demonstrated that roasting enhances certain allergenic properties of peanuts. We investigated possible mechanisms that may explain divergence in in vitro and in vivo allergenicity of differentially roasted peanuts. The major peanut allergens, Ara h 1 and Ara h 2, were purified from raw (R), light roast (LR) and dark roast (DR) peanuts, subjected to digestion with pepsin and trypsin, and analyzed for IgE binding. Roasting induced sugar modifications. Also, whole peanut proteins extracted from R, LR, and DR samples were used to sensitize mice, which were prick skin tested with the same allergens to measure the degree of sensitization. Ara h 1 and Ara h 2, purified from roasted peanuts, are more resistant to digestive enzymes. A correlation is seen between IgE binding and sugar modifications on long lived fragments. Interestingly, the digestion pattern of Ara h 1 and Ara h 2 from R, LR and DR peanuts were different. Additionally, we determined that mice sensitized with roasted peanuts had higher skin test reactivity than mice sensitized with raw peanut proteins. Our results indicate that many of the IgE binding digestion resistant fragments are modified with sugar by-products that occur as a result of roasting. Also, in some occasions roasting alters the IgE-binding fragments that survive digestion, and therefore, quite possibly, the allergenic epitopes. These altered epitopes may be responsible for in vivo data that demonstrate mice are more likely to be sensitized to roasted than raw peanuts.