High level expression of functionally active human lactoferrin in silkworm larvae.

In this paper, recombinant human lactoferrin (rhLf) was expressed very well using Bombyx mori nuclear polyhedrosis baculovirus expression system. Infection of silkworm larvae with recombinant virus, vBm-hLf, the rhLf was efficiently secreted into larvae hemolymph and the concentration of product purified was about 65 microg/ml. The isolated rhLf molecular mass was approximately 78 kDa, lower than that of the human lactoferrin (hLf) standards, which may be due to incomplete glycosylation or protein degradation. Furthermore, the rhLf was characterized and its biological activities were evaluated by in vivo bioassay using dextran sodium sulfate (DSS)-induced colitis mouse model that mimics some characteristics of colitis disease in human. We conclude that silkworm expression system can be used successfully to express functional human lactoferrin.