Tyrosinase-Related Protein2 Peptide with Replacement of N-Terminus Residue by Cysteine Binds to H-2K and Induces Antigen-Specific Cytotoxic T Lymphocytes after Conjugation with CpG-DNA.

Recent studies have shown the potent efficacy of peptide-based vaccines for cancer immunotherapy. Immunological performance is optimized through the co-delivery of adjuvant and antigenic peptide molecules to antigen-presenting cells simultaneously. In our previous study, we showed that a conjugate consisting of 40-mer CpG-DNA and an antigenic ovalbumin peptide through disulfide bonding could efficiently induce ovalbumin-specific cytotoxic T lymphocyte (CTL) responses in vivo.

Immune Responses and Antitumor Effect through Delivering to Antigen Presenting Cells by Optimized Conjugates Consisting of CpG-DNA and Antigenic Peptide.

Immunotherapy using antigen-specific cytotoxic T lymphocytes (CTLs) has become one of the most attractive strategies for cancer treatment. For the induction of antigen-specific CTLs , the co-delivery of CpG-DNAs and antigens to the same antigen-presenting cells (APCs) is a promising strategy. In this study, we prepared conjugates consisting of 40mer of CpG-DNA (CpG40) and antigenic peptide (OVA), which have the following distinctive features: (1) multiple CpG motifs in a molecule; (2) cleavage in the cytosol because of the disulfide bonding via cysteine residue between peptide and CpG-DNA; (3) conjugation designed to induce antigen presentation on MHC class I molecules.