Application of a food allergy murine model to study the cross reactivity between allergens from cow’s milk and soybean

REY, AMANDA; CURCIARELLO, RENATA; FOSSATI ALBERTO; PETRUCCELLI, SILVANA; DOCENA, GUILLERMO H.

Córdoba, Argentina

Congreso; VII Congreso Latinoamericano de Inmunología; 2005

Asociación Latinoamericana de Inmunología

Our aim was to demonstrate the in vitro and in vivo crossreactivity between bovine caseins and 7S and 11S soy globulins using a cow´s milk murine model of food allergy(CMFA). BALB/c mice were intragastric and intraperitoneal sensitized using whole CM extract and different adjuvants during a 30 day-immunization protocol. Total and specific antibodies (IgE, IgG, IgG1, IgA) were measured by ELISA and EAST using whole soy protein extract and soy recombinant proteins (A5A4B3, alpha subunit of the beta conglicinin) as coating antigens. Spleen cells were culture, cell proliferation and cytokines (IL-4, IL-5, IFNg by ELISA) were assayed. Skin tests were performed to detect specific IgE on mast cells. An oral challenge with whole soy extract was carried out. Only mild signs could be accomplished, while a good increase in the level of the crossreactive antibodies could be measured (IgE, IgG, IgG1 and IgA). Proliferation assays rendered a significant proliferation index when cow´s milk, bovine casein, whole soy or recombinant soy proteins were employed as antigens. As regard to cytokine production the most significant variation was an increase in IL-5 (500-1000 pg/ml). Skin tests were positive as compared to the negative control. The specific antigen (CM) was also used to check the specificity of the immune response elicited. In conclusion, the CMFA has proved to be suitable to study the previously characterized cross reaction between soy and CM allergens. This crossreactivity could be the basis to understand the intolerance observed in CM allergic patients that undergo CM replacement by soy formula.