Production of biologically active recombinant bovine interferon-gamma by two different baculovirus gene expression systems using insect cells and silkworm larvae

The full-length bovine interferon-gamma (bIFN-gamma) cDNA, including the se cretion signal peptide coding region was recloned into baculovirus transfer vectors pAcYM1 and pBm050, These vectors were co-transfected with Autograp ha californica nuclear polyhedrosis virus (AcNPV) or Bombyx mori nuclear po lyhedrosis virus (BmNPV) DNA into Spodoptera frugiperda cells (SF21AE) and Bombyx mori cells (BmN), respectively. The recombinant viruses, named AcBIF N-gamma and BmBIFN-gamma, were then recovered. Recombinant bIFN-gamma (rbIF N-gamma) was accumulated in the culture fluid of AcBIFN-gamma -infected Tri choplusia ni cells and BmBIFN-gamma -infected silkworm larvae. These rbIFN- gamma forms were shown to be glycosylated 20 and 22 kDa proteins as confirm ed by SDS-PAGE and tunicamycin treatment. These products were sensitive to cystein proteinase, Both rbIFN-gamma proteins, showed high-level biological activities by plaque reduction assay using vesicular stomatitis virus, and MHC class II antigen induction on bovine macrophage cells. (C) 2001 Academ ic Press.