Retention of immunogenicity produced by mucin 1 peptides with glycosylation site substitutions.

Mucin1 (MUC1) with altered glycosylation behaves as an antigen unique to adenocarcinomas (ADCs). As a step toward DNA vaccines, the goal of this work was to determine whether MUC1 peptides substituted with an asparagine at O-linked glycosylation sites, might expose MUC1 peptide backbone to serve as immunogens to generate cytotoxic T lymphocytes (CTL) from peripheral blood mononuclear cells of patients with ADCs. Substitution of some or all tyrosine and serine residues by asparagine in MUC1 did not inhibit the generation of mucin-specific CTLs. This suggests that MUC1 tandem repeat altered sequences to prevent O-linked glycosylation may be useful as DNA vaccines with tumor specificity.