A SHORT PEPTIDE FROM THE MAJOR SOYBEAN ALLERGEN (P34) IS A PROMISING TOOL FOR COW'S MILK ALLERGY IMMUNOTHERAPY

CANDREVA, ANGELA MARIA; CURCIARELLO, RENATA; SMALDINI PAOLA LORENA; MUGLIA, CECILIA I; CANZIANI, KARINA; PETRUCCELLI, SILVANA; DOCENA, GUILLERMO H

Buenos Aires

Congreso; I meeting LASID-FAIC-SAI; 2015

Foodallergy is caused by a breakdown in immunologic tolerance. Nowadays there is nostandardized and approved immunointervention procedure. We aimed to identify T-cellepitopes containing peptides for a tolerogenic immunotherapy against thecross-reactive cow´s milk proteins (CMP) using an IgE-mediated food allergymouse model.B and T epitopes were mapped inthe soy major allergen P34 using specific antisera to bovine caseins, splenocytesfrom cow´s milk allergic (CMA) mice and IgE-containing sera and T-cells from CMApatients. A short peptide selected (CtP34) was evaluated in an oralimmunotherapy (OIT). Balb/c mice were gavaged with CMP, CtP34 or saline priorto oral sensitization with CMP and cholera toxin, and then orally challengedwith CMP. Immune response was evaluated by in vitro (serum antibodiesand cytokine secretion) and in vivo assays(clinical signs and cutaneous tests).We found that the Ctportion of P34 contained B and T epitopes. Then, 11 synthetic peptides spanningthis portion were tested for cell proliferation and cytokine production usingsplenocytes from sensitized mice and a human T-cell line from CMA patients. Theselected CtP34-peptide was only recognized by CMP-specific IgG, but not by IgEantibodies and stimulated proliferation of CMP-specific T-cells. Finally, OITwith CtP34 reduced clinical signs (average scores: 2,4 for treated vs 3,5 for sensitizedmice), prevented CMP-specific Th2 cytokines production.In conclusion, the OITwith CtP34 prevented the oral sensitization with cow´s milk allergens andcontrolled the allergic reaction. This would set the basis to perform an oralimmunotherapy based on cross-reactivity.