Production of biologically active hG-CSF by transgenic plant cell suspension culture

In order to produce recombinant human granulocyte colony-stimulating factor (hG-CSF) through transgenic tobacco cell suspension culture, we initially cloned the hG-CSF gene with its own signal peptide from a TPA stimulated THP-1 cell line. The gene was sub-cloned into the plant expression vector, pMY27, and transformation of tobacco was conducted by using A. tumefaciens harboring the hG-CSF gene. Cell suspension culture was established from the leaf-derived calli of transgenic tobacco. Biologic activity of the produced hG-CSF was confirmed by measuring the proliferation of the hG-CSF dependent NFS60 cells. The maximum concentration of hG-CSF produced and secreted by cultured transgenic tobacco suspensions was about 105 μg/liter, occurring 9 days after inoculation of the culture.