A DNA vaccine based on a shuffled E7 oncogene of the human papillomavirus type 16 (HPV 16) induces E7-specific cytotoxic T cells but lacks transforming activity

• Published in: Vaccine Vol. 19; no. 30; pp. 4276 - 4286
• Main Authors: Osen, Wolfram, Peiler, Tanja, Öhlschläger, Peter, Caldeira, Sandra, Faath, Stefan, Michel, Nico, Müller, Martin, Tommasino, Massimo, Jochmus, Ingrid, Gissmann, Lutz
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 20.07.2001; Elsevier
• Subjects: 3T3 Cells; AE7 protein; Animals; Biological and medical sciences; Cell Line; Cell Transformation, Neoplastic; DNA immunization; DNA shuffling; E7 protein; Epidemiology. Vaccinations; Fundamental and applied biological sciences. Psychology; General aspects; HPV 16 E7 oncoprotein; Human papillomavirus 16; Immunization; Infectious diseases; Medical sciences; Mice; Mice, Inbred C57BL; Microbiology; Oncogene Proteins, Viral - genetics; Oncogene Proteins, Viral - immunology; Papillomavirus E7 Proteins; Papillomavirus Infections - prevention & control; Papillomavirus Vaccines; Plasmids; T-Lymphocytes, Cytotoxic - immunology; Tumor Virus Infections - prevention & control; Vaccines, antisera, therapeutical immunoglobulins and monoclonal antibodies; Vaccines, DNA - immunology; Viral Vaccines - immunology; Virology; DNA shuffling; DNA immunization; HPV 16 E7 oncoprotein; Papillomavirus; Virus; Human papillomavirus 16; Human papillomavirus; Specificity; T-Lymphocyte; Cytotoxicity; Papovaviridae; Onc gene; Genetic vaccine
• ISSN: 0264-410X; 1873-2518
• DOI: 10.1016/S0264-410X(01)00154-2

Vaccination with oncogene-derived DNA for anti-cancer treatment carries a risk of de-novo tumor induction triggered by the persisting recombinant DNA. We hypothesized that an oncoprotein whose primary sequence has been rearranged (‘shuffled’) to maintain all possible T cell epitopes still induces cytotoxic T cells against the authentic protein but is devoid of transforming properties. As a model antigen, we used the E7 oncoprotein of the human papillomavirus (HPV) type 16, the major cause of cervical cancer. We have generated an artificial E7 molecule in which four domains were rearranged and, in order to maintain all possible T cell epitopes, certain sequences were duplicated. Upon transfection of this shuffled E7 gene (E7 SH) into RMA cells, presentation of an E7 D b-restricted T cell epitope was shown by an E7-specific CTL line in vitro. Immunization of C57BL/6 mice with E7 SH DNA induced E7-specific CTL and also conveyed protection against E7-positive syngeneic tumor cells. No transforming activity of E7 SH DNA in NIH3T3 cells was detected, as determined by focus formation, induction of S-phase under conditions of serum deprivation and degradation of endogenous pRB. Our results suggest that DNA shuffling may become a promising concept for DNA-based anti-cancer vaccines.