Expression of foot-and mouth disease virus proteins in vitro with eukaryotic expression plasmid
The genomic fragment P12X3C3D that includes full length P1, 2A, 3C, 3D and a part of 2B of foot-and-mouth disease virus (FMDV) was obtained by PCR. After being digested by restriction enzymes respectively, the fragment P12X3C3D was cloned into pcDNA3.1(+) that had been digested by the same enzymes and the recombinant plasmid was named pcDNA3.1/P12X3C3D. Meantime, P12X3C3D was inserted into pTARGET~(TM) expression vector and the resulted recombinant plasmid was named pTARGET/P12X3C3D. Recombinant plasmids were identified by restriction enzyme analysis and nucleic acid sequencing. Furth4er, BHK-21 cells were transfected with pcDNA3.1/P12X3C3D, pTAGRET/P12X3C3D by using lipoid. The proteins of foot-and-mouth disease virus expressed in BKH-21 cells were confirmed by sandwich-ELISA and IFA, and the capsid of FMDV was observed under electron microscope. The results showed P12X3C3D was cloned into eukaryotic expression plasmid correctly. The recombinant eukaryotic expression plasmid pcDNA3.1/P12X3C3D, pTARGET/P12X3C3D could express proteins of foot-and-mouth disease virus in BKH-21 cells, and the expressed proteins by pTARGET/P12X3C3D had immunocompetence and could assembly into empty capsid structures of FMDV.