[Expression of porcine interleukin-6 in Pichia pastoris]

As a kind of pleiotropic cytokine, Interleukin-6 (IL-6) becomes more and more popular in the fields of disease diagnosis and candidate adjuvants. In this study, the porcine Interleukin-6 (pIL-6) cDNAs un-coding signal peptides was cloned into pPIC9K (the expression vector of Pichia pastoris) to construct the pPIC9K-IL6, which was further transformed into P. pastoris GS115 strain. After being induced by 1% methanol, the recombinant strain excreted a protein in supernate of culture, with molecular weight of 24.5KD approximately, which was proved to be pIL6 through SDS-PAGE and western blotting. This P. pastoris product wasn't modified by N-hyperglycosylation. After purified, pIL-6 could reach to 8 x 10(4) IU/mg of bioactivity unit by the cell proliferation of B9 assay. Through researching the characters of the recombinant protein pIL6, we have made a great progress on the study of rpIL6 as veterinary vaccine's adjuvant.