A Lewis(y) epitope mimicking peptide induces anti-Lewis(y) immune responses in rabbits and mice.

Lewis(y) carbohydrate antigens are abundant on the surface of many carcinomas. Mab B3 directed against this carbohydrate antigen has been used to make an immunotoxin that is very cytotoxic to cancer cells expressing the Lewis(y) antigen. Mab B3 was also used to screen a phage-displayed peptide library and identified a peptide mimicking the Lewis(y) epitope. In this report, we demonstrate that the Lewis(y) epitope-mimicking peptide induces anti-Lewis(y)immune responses in both rabbits and mice. In addition, Lewis(y) antigens induce anti-peptide immune responses. These results indicate that carbohydrate-mimicking peptides provide a novel strategy to elicit immune responses for tumor-associated carbohydrates.