Cross-reactivity between the soybean protein P34 and bovine caseins

CANDREVA ANGELA; SMALDINI, PAOLA; CURCIARELLO, RENATA; CAUERHFF, ANA; FOSSATI, CARLOS ALBERTO; DOCENA, GUILLERMO HORACIO; PETRUCCELLI, SILVANA

Allergy, Asthma & Immunology Research

Korean Academy of Asthma, Allergy and Clinical Immunology and the Korean Academy of Pediatric Allergy and Respiratory Disease

Lugar: Yeongtong-gu; Año: 2015 vol. 7 p. 60 - 68

2092-7355

Soy-based formulas are widely used as dairy substitute to treat milk allergic patients. However, reactions to soy have been reported in a small proportion of patients with IgE-mediated allergy to milk. The aim of this work was to analyze if P34 a mayor soybean allergen might be involved in this intolerance. Methods:In vitro recognition of P34 was evaluated by immunoblotting, competitive ELISA and BAT using sera from allergic patients. In vivo cross-reactivity was studied using an IgE-mediated milk allergy mouse model. Results: P34 was recognized by IgE antibodies from sera of milk allergic patients, casein specific monoclonal antibodies and sera from milk allergic mice. Spleen cells from sensitized mice incubated with milk, soy or P34 secreted IL-5 and IL-13, while IFN-ã remained unchanged. In addition, the cutaneous test was positive with P34 in allergic animals. Importantly, milk-sensitized mice developed immediate symptoms following sublingual exposure to P34. Conclusions: The results presented herein demonstrate that P34 shares epitopes with bovine casein, which are responsible for inducing hypersensitivity symptoms in milk allergic mice, thus showing the clinical relevance of this cross-reactivity. This is the first report that demonstrates the in vivo cross-allergenicity of P34, which could set a new avenue for the development of a mucosal vaccine.