title: Immunization strategy against cervical cancer involving an alphavirus vector expressing high levels of a stable fusion protein of human papillomavirus 16 E6 and E7.
abstract: We are developing immunization strategies against cervical carcinoma and premalignant disease, based on the use of recombinant Semliki Forest virus (SFV) encoding the oncoproteins E6 and E7 from high-risk human papilloma viruses (HPV). Thus far, protein-based, as well as genetic immunization studies have demonstrated low to moderate cellular immune responses against E6 and E7. To improve these responses, we modified the structure and expression level of the E6 and E7 proteins produced by the SFV vector. Specifically, a construct was generated encoding a fusion protein of E6 and E7, while furthermore a translational enhancer was included (enhE6,7). Infection of cells with recombinant SFV-enhE6,7 resulted in the production of large amounts of the E6,7 fusion protein. The fusion protein was more stable than either one of the separate proteins. Immunization of mice with SFV-enhE6,7 resulted in strong, long-lasting HPV-specific cytotoxic T lymphocyte responses. Tumor challenge experiments in mice demonstrated that immunization with SFV-enhE6,7 resulted in prevention of tumor outgrowth and subsequent protection against tumor re-challenge.
authors.affiliation: University of Groningen, Department of Medical Microbiology, Molecular Virology Section, Groningen, The Netherlands.
authors.forename: T
authors.initials: T
authors.lastname: Daemen
authors.forename: J
authors.initials: J
authors.lastname: Regts
authors.forename: M
authors.initials: M
authors.lastname: Holtrop
authors.forename: J
authors.initials: J
authors.lastname: Wilschut
mesh_terms: D000818:Animals; D015153:Blotting, Western; D019496:Cancer Vaccines / Q000276:immunology; D002460:Cell Line; D006224:Cricetinae; D003602:Cytotoxicity, Immunologic; D005260:Female; D005822:Genetic Vectors / Q000276:immunology; D007114:Immunization / Q000379:methods; D051379:Mice; D008810:Mice, Inbred C57BL; D009368:Neoplasm Transplantation; D009856:Oncogene Proteins, Viral / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D027383:Papillomaviridae / Q000235:genetics* / Q000276:immunology; D050725:Papillomavirus E7 Proteins; D030361:Papillomavirus Infections / Q000150:complications / Q000276:immunology; D012097:Repressor Proteins; D012672:Semliki forest virus / Q000235:genetics; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D014412:Tumor Virus Infections / Q000150:complications / Q000276:immunology; D002583:Uterine Cervical Neoplasms / Q000517:prevention & control* / Q000821:virology
chemical_list: D019496:Cancer Vaccines; C068651:E6 protein, Human papillomavirus type 16; D009856:Oncogene Proteins, Viral; D050725:Papillomavirus E7 Proteins; D012097:Repressor Proteins; C059731:oncogene protein E7, Human papillomavirus type 16