A novel fusion protein-based vaccine comprising a cell penetrating and immunostimulatory peptide linked to human papillomavirus (HPV) type 16 E7 antigen generates potent immunologic and anti-tumor responses in mice

The ultimate success of cancer vaccination is dependent upon the generation of tumor-specific CTLs. In this study, we designed and evaluated a novel fusion protein comprising a cell penetrating and immunostimulatory peptide corresponding to residues 32–51 of the Limulus polyphemus protein (LALF32–51) linked to human papillomavirus (HPV) 16 E7 antigen (LALF32–51–E7). We demonstrated that LALF32–51 penetrates the cell membrane and delivers E7 into cells. In a preclinical model of HPV16-induced cervical carcinoma we showed that vaccination with adjuvant-free LALF32–51–E7 fusion protein significantly improves the presentation of E7-derived peptides to T-cells in vitro and induces suppression of tumor growth.