Expression of human papillomavirus type 16 L1 structure gene in Sf9 cells and its products assembling into virus like particles

Objective To study the biological activities of the L1 gene products of human papillomavirus 16 (HPV16) which is believed to be related with cervical cancer and many of other human cancers. Methods The HPV16 L1 gene was amplified from pBSSK B/16L1 (derived from Bowen's disease tissue of Chinese woman) by the PCR, and the L1 gene was recombined into the baculovirus transfer vector pFastbacⅠ; The recombinant baculovirus was generated by the action of Tn7 transposon in E. coli strain, DH10Bac, with the action of Tn7 transposon, the HPV16 L1 gene carrying the polyhedrin promoter, was integrated into the baculovrius genome DNA. The insect Sf9 cells were transfected with the recombinant baculovirus, Sf9 cells infected by the recombinant baculovirus of HPV16 L1 were emebeded, sectioned and stained, then examined by transmission electron microscopy (TEM). Results The L1 proteins were efficiently expressed in Sf9 cells, and the L1 antibody combined specially the proteins in Western blot, L1 proteins takes 31% of the Sf9 cell total proteins. TEM observation showed many recombinant baculoviruses and virus like particles (VLP) which were formed by HPV16 L1 protein monomers in Sf9 cell nucleic. The BALB/c mice immunization results showed that the expressed HPV16 L1 proteins had good immunogenicity. Conclusion The results suggested that the results will be valuable for epidemiological investigation, the structural biological study of HPV16 L1 protein, development of the vaccine as well as other related researches HPV.