The preparation of human papillomavirus type 58 vaccine and exploring its biological activity and immunogenicity in vitro.

OBJECTIVES

Human papillomavirus (HPV) type 58 is the second most prevalent virus infection among Chinese women. To develop an HPV58 vaccine that combines both prophylactic and therapeutic functions, we generate a chimeric virus-like particle (cVLP).

METHODS

The cVLPs contain both whole length L1 and parts of E7 peptides either from E7 amino acids (aa) 50 to aa72 or from E7 aa4 to aa12. The HPV58 L1-E7aa50-72 and L1-E7aa4-12 fusion proteins were revealed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and confirmed by Western blot (Supplementary Digital Content 1, http://links.lww.com/IGC/A40, which shows alignment of the protein sequence between HPV58 L1-E7aa50-72/4-12 and standard sequence). Protein folding and location of cVLPs were identified by transmission electron microscope. The immunogenicity of the fusion protein was tested by enzyme-linked immunospot assay.

RESULTS

Transmission electron microscope showed that the fusion protein formed cVLPs by self-assembly and the majority of particles located in the nucleus of the sf-9 insect cells. The cVLPs displayed a strong ability to agglutinate erythrocytes, which is distinguished from the parental VLPs. In addition, the purified HPV58 L1-E7aa50-72 or L1-E7aa4-12 fusion protein induced significant numbers of interferon γ-expressing E7aa50-72- or E7aa4-12-specific CD8 T cells.

DISCUSSION: Our results indicate that the insertion of the E7aa50-72 or E7aa4-12 peptides behind L1 did not disrupt the assembly of cVLPs and provided potent immunogenicity and bioactivity, which created a powerful basis for further preparations of HPV58 vaccines with prophylactic and therapeutic effects for the treatment of HPV58-related diseases including cervical cancer.