A short peptide from the major soybean allergen (p34) is a promising tool for cow's milk allergy immunotherapy

CANDREVA ANGELA; CURCIARELLO, RENATA; SMALDINI, PAOLA; MUGLIA, CECILIA; ORSINI DELAADO, M LUCIA; CANZIANI, KARINA; PETRUCCELLI, SILVANA; DOCENA, GUILLERMO HORACIO

Buenos Aires

Congreso; First International Congress of LASID FAIC SAI, IV Meeting LASID and LXIII Congreso Anual de la Sociedad Argentina de Inmunología; 2015

Sociedad Argentina de Inmunología

Food allergy is caused by a breakdown in immunologic tolerance. Nowadays there is no standardized and approved immunointervention procedure. We aimed to identify T-cell epitope?containing peptides for a tolerogenic immunotherapy against the cross-reactive cow´s milk proteins (CMP) using an IgE-mediated food allergy mouse model.B and T epitopes were mapped in the soy major allergen P34 using specific antisera to bovine caseins, splenocytes from milk allergic mice, and IgE-containing sera and T cells from milk allergic patients.lymphocytes-A short peptide selected from the C-terminal portion (PdP34) was in vivo evaluated in an oral immunotherapy (OIT). Balb/c mice were gavaged with CMP, soy peptide (PdP34) or saline prior to oral sensitization with CMP and cholera toxin, and then orally challenged with CMP. Immune response was evaluated with in vitro (serum antibodies; cytokine secretion) and in vivo assays (clinical score and cutaneous tests).We found that the Ct portion of P34 contained B and T epitopes. Then, 11 synthetic peptides spanning this portion were tested for cell proliferation and cytokine production using splenocytes from sensitized mice and a human T cell line from allergic patients. The selected PdP34 peptide was only recognized by CMP-specific IgG, but not by IgE antibodies. This peptide stimulated proliferation of CMP?specific T cells. Finally, OIT with PdP34 reduced clinical signs (average scores 2,4 vs 3,5 for treated vs sensitized mice, respectively), prevented CMP-specific Th2 cytokines production and IgE secretion..In conclusion, the oral administration of soy PdP34 prevented the oral sensitization with cow´s milk allergens and controlled the allergic reaction. This would set the basis to perform an oral immunotherapy based on cross-reactivity between soy and milk allergens.