IL-21 expression in hepatoma cell line H22 and its biological activity

Objective:To construct a recombinant eukaryotic expression vector mIL-21-pcDNA3.1 and transfect it into hepatoma cell line H22, so as to assess the biological activity of mIL-21. Methods: The gene fragment encoding mouse IL-21 was amplified by RT-PCR, and was then cloned into eukaryotic expression plasmid pcDNA3.1 to form recombinant plasmid mIL-21-pcDNA3.1. The recombinant plasmid is verified by DNA sequencing. mIL-21-pcDNA3.1 was transfected into H22 cells with lipofect regent, and its expression was detected by RT-PCR and Western blotting analysis. The effects of mIL-21-pcDNA3.1 on proliferation of T cells and cytotoxicity of NK cells were studied. Results: The recombinant plasmid mIL-21-pcDNA3.1 was confirmed by DNA sequencing. The expression of mIL-21 in H22 cells was confirmed by RT-PCR and Western blotting analysis. MTT results showed that stimulation index (SI) of T cells stimulated with mIL-2-H22 cell supernatant was 3.412±0.312, and the SI of ConA combination stimulating group was 4.673±0.450; both were significantly higher than those in the mock vector transfected (1.465±0.103) and untransfected groups (1.447±0.245, P0.01). The cytotoxicity of NK cells in mIL-21-H22 cell supernatant group was (81.66±4.26)%, significantly higher than those in the mock vector transfected ([34.74±5.52]%) and untransfected groups ([33.61±1.42]%). Conclusion: The expression of mIL-21-pcDNA3.1 plasmid in H22 cells can enhance the proliferation of T cells and the cytotoxicity of NK cells, which lays a foundation for its role in the research of anti-hepatoma.