[Eukaryotic expression of recombinant porcine single-chain IL-12 and its biologic activity].

AIM: To express the recombinant porcine single-chain interleukin-12 (pscIL-12) gene in CHO-K1 cells, and identify biological activity of pscIL-12 fusion protein. METHODS: The recombinant pcDNA3.1(+)-pscIL-12 plasmid was transfected into the CHO-K1 cells using Sofast(TM); reagent. The levels of pscIL-12 fusion protein and IFN-γ produced by human peripheral blood mononuclear cells (PBMCs) stimulated with the supernatant of CHO-K1 cells were detected by ELISA. NK cell cytotoxicity was tested by MTT assay. The lymphocyte proliferation was examined by flow cytometry. RESULTS: ELISA showed that the transfected CHO-K1 cells had a relatively higher expression of pscIL-12 fusion protein. And the pscIL-12 fusion protein possessed strong bioactivities in enhancing the NK cell cytotoxicity, increasing the IFN-γ production, and stimulating the lymphocyte proliferation. CONCLUSION: CHO-K1 cells transfected with pcDNA3.1(+)-pscIL-12 recombinant plasmid can successfully express pscIL-12 fusion protein, which has the expected biological activities.