Construction and characterisation of a recombinant fowlpox virus that expresses the human papilloma virus L1 protein

BACKGROUND: Human papilloma virus (HPV)-16 is the most prevalent high-risk mucosal genotype. Virus-like-particle (VLP)-based immunogens developed recently have proven to be successful as prophylactic HPV vaccines, but are still too expensive for developing countries. Although vaccinia viruses expressing the HPV-16 L1 protein (HPV-L1) have been studied, fowlpox-based recombinants represent efficient and safer vectors for immunocompromised hosts due to their ability to elicit a complete immune response and their natural host-range restriction to avian species. METHODS: A new fowlpox virus recombinant encoding HPV-L1 (FP(L1)) was engineered and evaluated for the correct expression of HPV-L1 in vitro, using RT-PCR, immunoprecipitation, Western blotting, electron microscopy, immunofluorescence, and real-time PCR assays. RESULTS: The FP(L1 )recombinant correctly expresses HPV-L1 in mammalian cells, which are non-permissive for the replication of this vector. CONCLUSION: This FP(L1 )recombinant represents an appropriate immunogen for expression of HPV-L1 in human cells. The final aim is to develop a safe, immunogenic, and less expensive prophylactic vaccine against HPV.