title: Purification and immunogenicity study of human papillomavirus type 16 L1 protein in Saccharomyces cerevisiae.
abstract: Human papillomavirus 16 virus-like particle (HPV16 VLP) vaccines expressed in Saccharomyces cerevisiae are under Phase III trial and are expected to be on the market in the near future. We have established a convenient and economical system for the prophylactic study of vaccines derived from HPV16 VLPs, and neutralization tests to standardize HPV serological methodology as a measure of validation. To purify HPV16 VLPs, yeast cells expressing HPV16 L1 protein were cultured and purified on a small scale by ultracentrifugation and size-exclusion and cation-exchange chromatography using open columns. The highly purified HPV16 L1 protein was identified by SDS-PAGE and Western blotting, and electron microscopic analysis confirmed that they self-assembled into VLPs. To test the efficacy of the purified VLPs as a vaccine and their ability to induce humoral immunity, we performed ELISA assays and observed a significant increase in the titer of anti-HPV16 VLPs antibodies in the sera of immunized mice. High anti-HPV16 neutralizing titers were found in the sera of vaccinated mice, as measured by a SEAP-based pseudovirus neutralization assay. These results would be useful in the evaluation of the immunogenicity of HPV vaccine candidates, and provide an international reference standard for HPV serological methods.
authors.affiliation: College of Pharmacy, Chung Ang University, 221 Huksuk-Dong, Dongjak-Ku, Seoul 156-756, Republic of Korea.
authors.forename: Se Na
authors.initials: SN
authors.lastname: Kim
authors.forename: Hye Sung
authors.initials: HS
authors.lastname: Jeong
authors.forename: Sue Nie
authors.initials: SN
authors.lastname: Park
authors.forename: Hong-Jin
authors.initials: HJ
authors.lastname: Kim
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D036022:Capsid Proteins / Q000276:immunology* / Q000302:isolation & purification*; D005260:Female; D007114:Immunization; D051379:Mice; D008807:Mice, Inbred BALB C; D009856:Oncogene Proteins, Viral / Q000276:immunology* / Q000302:isolation & purification*; D053918:Papillomavirus Vaccines / Q000276:immunology* / Q000302:isolation & purification; D011994:Recombinant Proteins / Q000276:immunology / Q000302:isolation & purification; D012441:Saccharomyces cerevisiae / Q000235:genetics; D014614:Vaccines, Synthetic / Q000276:immunology* / Q000302:isolation & purification; D014771:Virion / Q000276:immunology
chemical_list: D000914:Antibodies, Viral; D036022:Capsid Proteins; D009856:Oncogene Proteins, Viral; D053918:Papillomavirus Vaccines; D011994:Recombinant Proteins; D014614:Vaccines, Synthetic; C063317:L1 protein, Human papillomavirus type 16