[Construction and expression of an eukaryotic recombinant plasmid from a hybrid gene of antigen for Plasmodium falciparum].

OBJECTIVE: To construct an eukaryotic recombinant plasmid with HGFSP, a hybrid gene encoding the antigen epitopes of MSA1, MSA2, RESA and CSP in different developing stages of Plasmodium falciparum (P. f.). METHODS: HGFSP was sub-cloned into an eukaryotic expression plasmid pcDNA3 from a prokaryotic recombinant plasmid pSK-HGFSP to construct the eukaryotic recombinant expression plasmid pc-HGFSP. The identified recombinant was then transfected into HepG2 cells with liposome-mediated method. The G418-selected positive cell clones were tested to identify the immunogenicity of HGFSP-expressing antigen. RESULTS: It was evidenced that HGFSP was correctly inserted into pcDNA3 by restriction enzymes map analysis. HGFSP-expressing antigen-specific fluorescent response was observed in pc-HGFSP-transfected HepG2 cells. The results of SDS-PAGE and Western-blotting showed that there was a 23 kD protein band, which can be specifically recognized by anti-sera of HGFSP-expressing protein in pc-HGFSP-transfected HepG2 cell lysis. CONCLUSION: Pc-HGFSP, an eukaryotic recombinant plasmid encoding hybrid antigen epitopes of P. f., was constructed successfully and the antigenicity of pc-HGFSP-expressing protein was confirmed.