Characterization of T cell epitopes in bovine α-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 α-lactalbumin (α-LAC) are unknown. Therefore, the aim of this study was to determine the T cell epitopes in α-LAC.


METHODS
Nineteen synthetic peptides spanning α-LAC were obtained. Cow's milk-specific T cell lines (TCLs) of 46 subjects were generated and tested for their specificity for α-LAC. The lines responding to α-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 α-LAC or lost their responsiveness during subsequent experiments, which indicates that α-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.


CONCLUSIONS
The immunogenicity of α-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.
Department of Dermatology/Allergology, University Medical Center Utrecht, Utrecht, The Netherlands.
Laura A P M
LA
Meulenbroek
Constance F
CF
den Hartog Jager
Ans F M
AF
Lebens
André C
AC
Knulst
Carla A F M
CA
Bruijnzeel-Koomen
Johan
J
Garssen
Léon M J
LM
Knippels
Els
E
van Hoffen
D000485:Allergens / Q000276:immunology; D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D018984:Epitopes, T-Lymphocyte / Q000276:immunology* / Q000627:therapeutic use*; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology; D007167:Immunotherapy; D007768:Lactalbumin / Q000276:immunology*; D008892:Milk / Q000276:immunology; D016269:Milk Hypersensitivity / Q000628:therapy*; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology
D000485:Allergens; D018984:Epitopes, T-Lymphocyte; D010446:Peptide Fragments; D007073:Immunoglobulin E; D007768:Lactalbumin