Expression and bio-activity analysis of recombinant goat IL-18 gene

The recombinant plasmid pET-gIL-18 harboring gIL-18 gene and pET32a(+) vector in E.coli BL21(DE3) was induced by 1 mmol/L IPTG for 4 h or more time for expression.The fusion protein of pET and gIL-18 was expressed and SDS-PAGE analysis indicated that the molecular weight of the recombinant protein is about 38 000.Western blotting test indicated that recombinant gIL-18 can react with specific poly-antibodies.The recombinant protein can stimulate the proliferation of PBMCs and induce IFN-γ production in MDBK cells after being denatured,re-natured and purified.The results showed that the recombinant protein have most of the bioactivities of native IL-18.The recombinant protein also can protect mice against the challenge of PRV virulent strains.The study is to clerify the biological activity of the recombinant interleukin-18 and helpful to the clinical use as the immune and therapy adjuvant.