[Construction and expression of multi-gene recombinant plasmid pEG-FP-N1-HBsAg-ROP2].

OBJECTIVE: To construct pEGFP-N1-HBsAg-ROP2 recombinant expression plasmid and transfect HEK293T cells for expression, and pay a way for Toxoplasma gondii nucleic acid vaccine development.

METHODS: According to the HBsAg gene sequence and pcDNA3-p30-ROP2 recombinant plasmid restriction sites, the HBsAg gene was amplified by PCR. The HBsAg gene was cloned into the pcDNA3-p30-ROP2 and instead of p30 gene. The HBsAg-ROP2 fragment was amplified by PCR and digested with Hind Ⅲ and Kpn Ⅰ to clone into the pEGFP-N1 eukaryotic expression vector and construct the recombinant pEGFP-N1-HBsAg-ROP2. The expression vector was transfected into HEK293T cells based on the identification of PCR amplification, restriction endonucleases and sequencing.

RESULTS: The PCR product of HBsAg was about 700 bp, which was consistent with the theoretical value. Two bands of about 5.4 kb and 1.9 kb were obtained after double enzyme digestion with pcDNA3HBsAg-ROP2 recombinant plasmid. The recombinant plasmid pEGFP-N1-HBsAg-ROP2 was double-digested to generate an empty vector fragment of about 4.7 kb and a band of about 1.9 kb of HBsAg-ROP2 fragment. The results of sequencing showed that the sequence was 99.84% identical with the published sequence in GenBank. The target plasmid was successfully transfected into HEK293T cells, and the expression was correct, the protein concentration was 3.08 mg/ml.

CONCLUSIONS: The recombinant plasmid pEGFP-N1-HBsAg-ROP2 is successfully constructed and expressed efficiently.