关键词: 干扰素Ⅱ型, 白细胞介素6, 肿瘤坏死因子

Abstract: Objective To construct a recombinant expression vector of human inter leukin-24 (hIL-24) gene and express it in E. coli M15, and to evaluate the bioactivity of IL-24 fusion protein． Methods The human IL-24 cDNA fragment was amplified from plasmid by polymerase chain reaction(PCR),and sequenced.PQE/hIL-24 was constructed by gene rearrangement,then it was transformed into E. coli M₁ 5.The expression of the target protein was induced with IPTG and purified by Ni²⁺ -NTA agarose column.The expressed recombinant hIL-24(rhIL-24) was identified by SDS-PAGE and Western blotting. Normal peripheral blood mononuclear cells(PBMCs) were cultivated with the expression protein for 48 and 72 h，the levels of IL-6,IFN-γ and TNF-α of PBMC sstimulated with rhIL-24 were detected by ELISA． Results The recombinant prokaryotic expression vector PQE/IL-24 was constructed successfully and expressed stably in E. coli M₁5. At about 18　400 of molecular weight,there was an induced protein band.The levels of IFN-γ, IL-6 and TNF-α in the group of cultivated with the expression protein were obviously higher than those in the groups without the expresson protein(P<0.05).The rhIL-24 had a strong bioactivity with natural IL-24 protein. Conclusion The recombinant expression vector PQE-IL-24 has been constructed successfully and has efficency expression in E.coli M15，rhIL-24 which biologic activties are same as natural IL-24 protein is obtained．

Key words: interferon　type Ⅱ, interleukin-6, tumor necrotic factor