Characterization Of T Cell Epitopes In Bovine Alpha-Lactalbumin

Background: Recent studies have indicated that peptides containing T cell epitopes may be used for immunotherapy. While for several cow's milk allergens the T cell epitopes have been described, the T cell epitopes in the major allergen alpha-lactalbumin (alpha-LAC) are unknown. Therefore, the aim of this study was to determine the T cell epitopes in alpha-LAC. Methods: Nineteen synthetic peptides spanning alpha-LAC were obtained. Cow's milk-specific T cell lines (TCLs) of 46 subjects were generated and tested for their specificity for alpha-LAC. The lines responding to alpha-LAC were subsequently tested to determine their activation in response to the peptides. Results: More than half of the TCLs generated did not respond to alpha-LAC or lost their responsiveness during subsequent experiments, which indicates that alpha-LAC has low immunogenicity. Only 8 TCLs recognized 1 or more peptides. The recognition of the peptides was diverse and no major epitopes could be defined. Conclusion: The immunogenicity of alpha-LAC is very low compared to other major allergens in cow's milk. Moreover, there seems to be no dominant epitope present in the protein. Therefore, it seems unlikely that peptides of this protein can be used for immunotherapy. (C) 2014 S. Karger AG, Basel