[Construction and expression of eukaryotic expression plasmid pcDNA3.1/hIL-18].

Aim: To construct an eukaryotic expression plasmid pcDNA3.1/hIL-18 and express it in mammalian cells.

Methods: cDNA encoding mature hIL-18 was cleavaged by enzyme digestion from mesomeric clone vector pGEM-T/hIL-18 and inserted into an eukaryotic expression plasmid pcDNA3.1 to construct a recombinant expression plasmid pcDNA3.1/hIL-18. Then the constructed plasmid was transfected into COS-7 and Rlc310 cells by liposome-mediated gene transfer method. hIL-18 expressed in transfected COS-7 and Rlc310 cells was detected by immunohistochemical staining and level of hIL-18 mRNA in transfected Rlc310 cells was assayed by RT-PCR.

Results: A recombinant eukaryotic expression plasmid pcDNA3.1/hIL-18 was successfully constructed and expressed transiently in COS-7 cells and stably in Rlc310 cells.

Conclusion: The construction and expression of pcDNA3.1/hIL-18 have been achieved successfully, which lays a foundation for further research on anti-tumor effect of IL-18.