Construction of a bicistronic expression vector containing human papillomavirus (HPV) type 6b L1 gene and its expression in mammalian cells

Objective To construct a bicistronic expression vector containing HPV type 6b L1 gene, to express the recombinant vector in mammalian cells, and to establish a cell strain stably expressing HPV6b L1 gene. Methods After endonuclease digestion and purification, the gene fragment of HPV6b L1 was cloned into the eukaryotic expression vector pIRES2-enhanced green fluorescent protein (EGFP). The identification of the recombinant was realized via endonuclease digestion and sequence analysis. Then, the recombinant plasmid pIRES2-HPV6bLl-EGFP was transfected into NIH3T3 (a mouse embryonic fibroblast cell line) cells. Subsequently, the expression of EGFP was observed by fluorescent inverted microscopy, and HPV6b L1 mRNA expression by reverse transcription (RT)-PCR. Results The recombinant plasmid pIRES2-HPV6bLl-EGFP was successfully constructed, transfected into N1H3T3 cells, and selected by G418. The expression of EGFP was seen under an inverted fluorescence microscoy. RT-PCR proved the expression of HPV6b LI mRNA in transfected cells. Conclusions The recombinant plasmid pIRES2-HPV6bLl-EGFP was successfully constructed and transfected into NIH3T3 cells. Inverted fluorescent microscopy and RT-PCR confirmed the successful expression of HPV6b L1 in NIH3T3 cells.