Production of a novel multi-epitope peptide vaccine for cancer immunotherapy in TC-1 tumor-bearing mice

In our previous research, several bioinformatic strategies were utilized to design an efficient multi-epitope peptide vaccine (MEV) against cancer.The designed vaccine consists of Wilms tumor-1 (WT-1) and human papillomavirus (HPV) E7 cytotoxic T lymphocyte (CTL) epitopes, tetanus toxin fragment C (TTFrC) and HLA-DR epitope (PADRE) helper T lymphocyte (HTL) epitopes and heparin-binding hemagglutinin (HBHA) as an immunostimulatory adjuvant. All segments were fused together by suitable linkers. In the current study, we cloned and expressed the designed MEV in E. coli. We subsequently performed in vivo preventative and therapeutic assays to evaluate antitumor efficacy of the vaccine against the HPV-16 E7-expressing murine tumor cell line TC-1 as a model for cancer immunotherapy. The results showed that in preventive experiments, vaccination with MEV significantly augmented the IgG antibody titer and the percentage of tumor-free mice compared to control groups (PBS and E7). Moreover, in therapeutic experiments, vaccination with MEV led to a reduction in the number of metastatic nodules, lung weights and the ratio of lung weights to body weights compared to other groups. In sum, our epitope vaccine could efficiently induce preventive and therapeutic antitumor immunity in TC-1 tumor bearing mice.