[Cloning and eukaryotic expression of mouse interleukin 21].

Aim: To clone mouse interleukin 21(mIL-21) gene and construct its eukaryotic expression vector.

Methods: mIL-21 cDNA was amplified from ConA-activated mouse T cells by RT-PCR. And then the cDNA was cloned into eukaryotic expression plasmid pcDNA3.1 to construct recombinant plasmid pcDNA3.1/mIL-21 which was introduced into Sp2/0 cells by lipofectin. Expression of mIL-21 gene was detected by RT-PCR and NK cytotoxicity assay.

Results: Recombinant plasmid pcDNA3.1/mIL-21 was constructed correctly and mIL-21 gene was expressed in transfected Sp2/0 cells.

Conclusion: mIL-21 gene was cloned and expressed successfully, which lays the foundation for further studying anti-tumor effect of mIL-21 gene therapy in animal models.