Evaluation of intrinsic allergenicity of amaranth seed, pinto bean and kidney bean using an adjuvant free mouse model of food allergy 2299638

Abstract

Abstract Introduction Food allergy is a growing public health problem of critical significance because of the heightened risk of potential for fatal systemic anaphylaxis. Most food allergies in the United States are caused by 9 common foods: Milk, egg, wheat, soy, peanut, tree nut, fish, shellfish, and sesame. Currently, the allergenicity potential of other foods besides these common foods is incompletely understood. In this study, we assessed the intrinsic allergenicity of protein extracts obtained from 3 commonly used foods: Amaranth seed (AS), pinto bean (PB), and kidney bean (KB). Methods Using an adjuvant-free transdermal sensitization (TS)/ oral elicitation (OE) mouse model of food allergy, we tested the hypothesis that these 3 foods will be intrinsically non-allergenic in this model. Groups of Balb/cJ mice (n = 10/group) were exposed to respective food proteins or saline via skin (once a week for 4 weeks) to test their sensitization potentials. Blood samples collected before and after skin exposures were used to measure food specific IgE antibody titers using an ELISA. Sensitized vs. control mice were orally challenged with the respective proteins to elicit anaphylaxis that were quantified by rectal thermometry and clinically assessed using symptom scoring method. Results Specific IgE was not detectable for any of the foods before skin exposures. However, after 4 transdermal exposures, significant specific IgE levels were elicited by all 3 food proteins. However, the oral challenge with PB or KB to sensitized mice or saline control mice elicited weak or no anaphylaxis. In contrast, oral challenge with AS to sensitized, but not control mice, elicited life-threatening anaphylaxis. Conclusion In summary: i) in contrast to PB, and KB, AS--that is becoming a popular food ingredient, exhibits high intrinsic potential to clinically sensitize mice for life-threatening oral anaphylaxis; and ii) TS/OE model is a useful preclinical testing tool to evaluate intrinsic allergenicity of food proteins. Funding Source US EPA STAR Grant RD83482201; USDA/NIFA: MICL02023, 02486, 02796 Topic Categories Immediate Hypersensitivity, Asthma, and Allergic Responses (HYP)