A study on cloning, expressing and investigating biological activity of recombinant chicken interferon produced from yeast Pichia pastoris

Abstract

Virus-infectious diseases are permanent threats and cause serious lost for chicken industry of our country. Thus, the development of a bio-product enhancing the immune system against viral-caused diseases on chicken is highly necessary. Aims of this study were to clone, to express and to investigate anti-viral activity of recombinant chicken interferon-α and interferon-γ (ChIFN) produced from yeast Pichia pastoris. Gene fragments encoding ChIFN-α and ChIFN-γ were obtained by PCR and PCR/SOE (Splicing Overlapping Extension) based on the chicken genome DNA. Expressing vectors pPIC9K bearing gene-encoding ChINF-α or ChIFN-γ were cloned and two clones of P. pastoris stably expressing ChIFN-α and ChIFN-γ were generated. The expression of ChIFN-α and ChIFN-γ in P. pastoris culture supernatant was identified by Tricine SDS-PAGE. The biological activity of recombinant ChIFN-α was investigated on the model of chicken embryo fibroblast infected with IBDV and NDV. In case of IBDV-infected cells, the survival rate of cells treated by 1.6 µg/ml ChIFN-α was 79-88%, significantly higher than that of cells treated by PBS which was 33-34%. With NDV-infected cells, the survival rate of cells treated by 1.6 µg/ml ChIFN-α was 81-90%, also obviously higher than that of cells treated by PBS which was 27-32%. In conclusion, recombinant ChIFN-α and ChIFN-γ were expressed successfully on yeast P. pastoris and ChIFN-α was functional to stimulate anti- IBDV and NDV activities of cells.