106. Oral Immunotherapy for Cow´s Milk Allergy Using a Mouse Model of Food Allergy,

DOCENA, GH; SMALDINI P; ORSINI DELGADO L; CURCIARELLO R,; CANDREVA ANGELA; FOSSATI CA; PETRUCCELLI S,

Dublin

Congreso; Congreso del Grupo Europeo de Imunidad de Mucosas; 2012

International Society for Mucosal Immunology

Food allergy is caused by a breakdown in immunologic tolerance and there is no approved therapy for this pathology. We aimed to induce oral tolerance to cow`s milk proteins (CMP) using CMP and cross-reactive soy proteins (SP) in a food allergy mouse model. Balb/c mice were gavaged with CMP (CMP Tol) or SP (PS Tol) prior to oral sensitization with CMP and cholera toxin, and then orally challenged with CMP. Immune response was evaluated with in vitro (serum IgE, IgG1, IgG2a and IgA level; IL-5, IL-13 and IFN-γ secretion by splenocytes and Foxp3 T cells in the intestinal mucosa) and in vivo assays (clinical score and cutaneous tests). We found a lower medium clinical score in tolerized mice with CMP or PS after the oral challenge, as compared to sensitized mice, with a reduction in mast cell reactivity in tolerized mice. Immunological changes include decreased specific IgE (1,57±0,2 vs 1,06±0.3 SP Tol; 0,52±0,1 CMP Tol) and IgG1, decreased IL-5 and IL-13 at the protein and mRNA level and induction of regulatory Tcells in lamina propria, Peyer´s patchs and mesenteric lymph nodes in tolerized mice. IgG2a and IgA levels were not modified. In conclusion, oral immunotherapy based on cross-reactivity between CMP and SP can be used to down-modulate the allergic specific immune response in CMP-sensitized mice. This approach could provide a new therapeutic intervention for CMP food allergy