Construction of eukaryotic expression plasmid and pShuttle plasmid containing CTLA4Ig gene

On the basis of the availability of the prokaryotic expression plasmid which expresses human CTLA4Ig(hCTA4Ig),the eukaryotic plasmid harboring hCTLA4Ig was constructed by using recombinant DNA technique.The recombinant eukaryotic expression plasmid was identified by digestion of restricted enzymes and sequencing.The protein of hCTLA4Ig was detected by ELISA in the conditioned medium after the plasmid was transfered into 293 cells.Then hCTLA4Ig gene fragment together with eukaryotic promotor was cut from eukaryotic expression plasmid and was inserted into plasmid pShuttle.Restriction enzyme analysis showed that pShuttle/hCTLA4Ig has been successfully obtained,and it lays a foundation for CTLA4Ig gene therapy.