Vaccination with carbohydrate peptide mimotopes promotes anti-tumor responses.

Tumor-associated carbohydrate (TAC) antigens are important targets in cancer vaccine efforts. Carbohydrates are, however, frequently poor immunogens, in that they are T-cell-independent antigens. Molecular mimicry of TAC by peptides is an alternative approach to generating anti-carbohydrate immune responses. Here we demonstrate that peptide mimotopes can elicit antibody responses that cross-react with representative human TAC antigens. Primary immunization with such a multiple antigenic peptide, along with QS-21 as adjuvant, elicits cytotoxic antibodies reactive with naturally occurring forms of TAC expressed on tumor cells, and vaccination of mice with peptide mimotopes reduced tumor growth and prolonged host survival in a murine tumor model.