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

CANDREVA A; CURCIARELLO, R; SMALDINI, P; MUGLIA C.I.; CANZIANI, K.; PETRUCELLI S; DOCENA, G.

Buenos Aires

Congreso; IV LASID Meeting LXIII Argentinean Immunology Society Meeting II French-Argentinean Immunology Meeting; 2015

Sociedad Latinoamericana de Inmunodeficiencias, Sociedad Franco-Argentina de Inmunología, Sociedad Argentina de Inmunología

Abstract: 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 epitopes 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 cow´s milk allergic (CMA) mice and IgE-containing sera and T-cells from CMA patients. A short peptide selected (CtP34) was evaluated in an oral immunotherapy (OIT). Balb/c mice were gavaged with CMP, CtP34 or saline prior to oral sensitization with CMP and cholera toxin, and then orally challenged with CMP. Immune response was evaluated by in vitro (serum antibodies and cytokine secretion) and in vivo assays (clinical signs 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 CMA patients. The selected CtP34-peptide was only recognized by CMP-specific IgG, but not by IgE antibodies and stimulated proliferation of CMP-specific T-cells. Finally, OIT with CtP34 reduced clinical signs (average scores: 2,4 for treated vs 3,5 for sensitized mice), prevented CMP-specific Th2 cytokines production.In conclusion, the OIT with CtP34 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.