[Development of Large Scale Silkworm-rearing Technologies for the GMP Production of Biologics]

There exists an increasing need to produce useful proteins in recombinant technologies. In particular, most biologics for medical purposes are produced as recombinant proteins. Various host cell/vector systems have been developed, but it remains difficult to efficiently produce large molecular weight proteins with complex structures. As a result of breeding for several thousand years, the silkworm has acquired the ability to synthesize bulk amounts of silk proteins. To utilize this capacity for the mass production of useful proteins, transgenic silkworms have been generated that synthesize recombinant proteins in the silk gland and secrete them into the silk cocoon. Using this transgenic silkworm system, various proteins, including antibodies, collagen, and fibrinogen, have been successfully produced and are being developed as materials for diagnostic or research-use reagents, as well as for cosmetics. Moreover, several silkworm-produced proteins are being developed as biologics for therapeutic use. Transgenic silkworms need to be reared under good manufacturing practices (GMP)-compliant conditions to produce biologics. Therefore, we have constructed a GMP-compliant pilot plant for producing biologics using transgenic silkworm, and are now developing silkworm-rearing technology under GMP-compliant conditions.