The identification of food allergen T-cell epitopes provides a platform for the development of novel immunotherapies. Despite extensive knowledge of the physicochemical properties of lien ovalbumin (OVA), a major egg allergen, the complete T-cell epitope map of OVA has Surprisingly not been defined in the commonly used BALB/c mouse model. In this study, spleen cells obtained from OVA-sensitized mice were incubated in the presence of 12-mer overlapping synthetic peptides, Constructed Using the SPOTS (R) synthesis method. Proliferative activity was assessed by 72-h in vitro assays with use of the tetrazolium salt WST-1 and led to identification of four mitogenic sequences, i.e., A39R50, S147R158, K263E274, and A329E340. ELISA analyses of interferon (IFN)-gamma and interleukin (IL)-4 productions in cell culture supernatants upon stimulation with increasing concentrations of peptides confirmed their nogenicity. Knowledge of the complete T-cell epitope map of OVA opens the way to a number of experimental investigations, including the exploration of peptide-based immunotherapy. (C) 2008 Elsevier Inc. All rights reserved.