Construction of eukaryotic express vector of chicken-18 gene and identification of bioactivity of its expressed protein

The whole segment of ChIL-18 gene was amplified by PCR from plasmid pMDCh-18. The PCR product was digested with HindⅢ and XbaⅠ, then inserted into pcDNA3.1 between HindⅢ and XbaⅠsites to generate a expression plasmid pcDNA3.1-ChIL-18(pChIL-18), and transformed into Escherichia coli JM109. The recombinant colonies were identified by the methods of restriction enzyme digestion,PCR and sequencing. The eukaryotic expression plasmid pChIL-18 had been successfully constructed. After the transfection of pChIL-18 into COS-7 cells, ChIL-18 mRNA expression was found in COS-7 cell. The SDS-PAGE analysis indicated that the expressed ChIL-18 protein had molecular weight of 23ku. The results of MTT assay showed that the expression of ChIL-18 protein in COS-7 cell could induce significantly transformation of chicken T lymphocytes.