Expression of goat IL-18 mature protein in Pichia mammalian expression system.

For expression of goat interleukin-18(gIL-18) in pichia pastoris system,the IL-18 gene was amplified by PCR and cloned into pPICZαA vectors,then transformed into pichia pastoris system GS115.High level expression of recombinant protein up to 100 mg/L was achieved following inducing with methanol.Bioactivity of recombinant protein was analyzed by MTT and MDBK-VSV methods.The enhanced immunity was measured by goat pox vaccine test.The recombinant protein could stimulate PBMCs proliferation and induce IFN-γ production in MDBK cells.It also showed immune enhancement to the antigen of goat pox vaccine.The recombinant gIL-18 expressing in yeast system retained nature bioactivity and could be a valuable resource for the large-scale clinical use as an immune adjuvant or therapeutic cytokines.