ORAL IMMUNOTHERAPY FOR FOOD ALLERGY IN A MILK ALLERGY MOUSE MODEL

ORSINI LUCÍA; PAOLA SMALDINI; FOSSATI ALBERTO; DOCENA GUILLERMO H.

Los Cocos

Congreso; LXI Reunión Anual de la Sociedad Argentina de Inmunología; 2013

Food allergy is a rising health concern worldwide and it is accepted that is caused by a breakdown in immunologic tolerance. The most efficient treatment is the strict avoidance of exposure to food allergens. Since it is a complex task in patients younger than 2 years, new studies for corrective therapies are mandatory. Nowadays there is no standardized or approved immunointervention procedure. We aimed to induce oral tolerance to cow`s milk proteins (CMP) using CMP in an IgE-mediated food allergy mouse model. Balb/c mice were intragastrically given CMP prior to (CMPprev) or after (CMPdes) sensitization with CMP and cholera toxin. Mice were orally challenged with CMP and the immune response was evaluated with in vitro (serum IgE, IgG1, IgG2a and IgA level; TNF-á, IL-6, IL-17A, IL-5, IL-13, IFN-ã, IL-10 and TGF-â secretion by spleen cells and Treg cells in the intestinal mucosa) and in vivo assays (clinical score and cutaneous tests).Histology was analyzed in gut specimens to evaluate the inflammatory infiltrate. We found a lower mean clinical score in CMPprev andCMPdesmice after the oral challenge with CMP, as compared to sensitized mice, with a reduction in skin mast cell reactivity in tolerized mice. Immunological changes include decreased specific IgE(1,57±0,2 vs0,87±0.2CMPdes; 0,52±0,1 CMPprev) and IgG1(2,07±0,7 vs 0,91±0,2 CMPdes; 0,11±0,05 CMPprev), decreased protein and mRNA level of IL-6, IL-5 and IL-13, and induction of IL-10-producing regulatory Tcells in duoenum (1,02±0,3% vs9,53±0,1% CMPdes; 10±0,4%CMPprev) and mesenteric lymph nodes () in tolerized mice. TGF-â, IgG2a and IgA levels were not modified.A mild inflammatory infiltrate of mononuclear cells was observed in duodenum of sensitized mice, which was completely reverted in treated mice. Hypereosinophilia was also controlled. Oral immunotherapy with milk proteins down-modulated the allergic specific immune response in CMP-sensitized mice. This approach could provide a new therapeutic anti-inflammatory intervention for CMP food allergy, either for prevention or desensitization.