Cloning of mature human Interleukim-18 Genes from human PBMC,Expression of the Protein in the E. coli

Objective To clone mature human interleukim-18 cDNA and express it by E.coli JM109.Methods The cDNA encoding mature human imterleukim-18 was amplified from total RNA of human peripheral blood monooonuclear cells(PBMC)by RT-PCR.The hIL-18 reconbinant prokaryotic expression plasmid was constructed by cloning this cDNA fragment into pGEX-3X,and transform the recombinant plasmid into the competent cells of E.coli JM109.The recombinant IL-18 protein's expression was induced by IPTG,the result was analysed by SDS-PAGE.Results Sequence analysis indicated that this cDNA is 100% homologt to the published hIL-18 cDNA sequence;The recombinant plasmid pGEX-3X-hIL-18 was constructed successfully;By induction of IPTG,the E.coli JM109 harbouring the recombinant plasmid(pGEX-3X-hIL-18)expressed recombinant fusion protein(rhIL-18-GST) with molecular weight 43KD.Conclusion We have cloned human IL-18 cDNA and expressed it by E.coli JM109.It is the basis for the study on biological roles of human IL-18 and for possible application in clinic in the future.