A novel mimovirus vaccine containing survivin epitope with adjuvant IL-15 induces long-lasting cellular immunity and high antitumor efficiency.

Abstract Numerous evidences have indicated that CD8 + cytotoxic T lymphocytes (CTLs) played a significant role in protecting host against tumors, thus CTLs have been involved as potentially relevant candidate targets of cancer immunotherapy. Moreover it is crucial to fully elucidate antigen-specific CTL response, especially high-avidity and long-lasting CTL response in vivo . In the present study, we reported a novel tumor vaccine (mimovirus), a viron-size particulate which consisted of a cell-penetrating peptide of Tat 49-57 , a CTL epitope peptide survivin 85-93 and a plasmid encoding murine interleukin-15 (IL-15). We demonstrated that this tumor vaccine could effectively mediate the expression of the gene and presentation of the tumor antigen derived peptide ex vivo . Furthermore, the tumor vaccine supported a robust memory CTL-mediated long-term immunity in vivo , which could effectively protect BALB/c mice against fatal CT26 tumor challenge and improve their survival. These findings suggest that the tumor vaccine may provide an alternative therapeutic strategy for cancer patients.