Production of Recombinant Human Keratinocyte Growth Factor from Bombyx mori (Lepidopera: Bombycidae) Bm5 Cells

Using silkworm Bombyx mori Bm5 cells, we established a stable cell line expressing the human keratinocyte growth factor (hKGF), named by the Bm5-hKGF cell, in which the protein hKGF is synthesized in the cell and secreted in the cell culture supernatant (CCS) at approximately 15-20 ng/㎖. When the Bm5-hKGF cell was co-expressed with B. mori protein disulfide isomerase (bPDI) cDNA, its secretion increased by about two times the original amount. Through wound healing migration assay, it was demonstrated that the secreted hKGF included in the CCS has a very powerful biological activity of keratinocyte proliferation. We expect to produce useful human recombinant proteins from silkworm cultured cells in large quantities at low prices.