Objective: To construct the eukaryotic expression recombinant plasmid of cadF gene of Campylobacter jejuni Pen: 19 and to identify its express in COS-7 cells.Methods: Total DNA of Campylobacter jejuni Pen:2?Pen:8?Pen:19 and Pen: 21 were used as templates respectively and cadF gene DNA with KpnI and EcoRI sites were amplified by PCR reactions using same primer.Because of its closest association with Guillain-Barré syndrome

the PCR product of Pen:19 was selected as target gene and inserted into the eukaryotic expression vector pcDNA3.1(+) and the recombinant plasmid pcDNA3.1(+)-cadF was constructed.The recombinant plasmid was identified by restriction enzyme digestion and PCR reaction and was confirmed by sequencing.The recombinant plasmid was then transfected into mammalian cell COS-7 for mRNA expression and the expression were investigated by RT-PCR reaction.Results: It was confirmed with restriction enzyme digestion and PCR reaction and sequencing that cadF gene was cloned into pcDNA3.1(+) successfully.The objective gene was amplified from COS-7 cell transfected with the recombinant plasmid pcDNA3.1(+)-cadF by RT-PCR.Conclusion: The eukaryotic expression recombinant plasmid pcDNA3.1(+)-cadF is constructed and expressed in COS-7 cell successfully.The results obtained lay the foundation for research on development of Campylobacter jejuni DNA vaccine.