Human lactoferrin (hLF) is an iron-binding glycoprotein of Mr 77,000 that belongs to the transferrin family. Based on extensive research showing antimicrobial, anti-inflammatory and immunomodulatory activities of hLF, the molecule is postulated to be involved in the innate host defence against infection and severe inflammation. The diverse biological properties of hLF may allow for a variety of applications in human healthcare. However, the limited availability of (human milk-derived) natural hLF has been a major hurdle for (clinical) studies on potential applications. To overcome this limitation the feasibility of large-scale production of functional recombinant hLF (rhLF) was studied. This thesis reports on the use of transgenic cows as protein production technology for rhLF and describes the characterization and safety testing of the purified molecule. The bovine mammary gland appears to be an attractive vehicle for producing large amounts of rhLF as constant expression levels, in the gram per liter range, have been obtained without affecting normal milk parameters. Characterization of purified rhLF revealed that the molecule closely matches the structure of natural hLF except for differences in glycosylation. The differential glycosylation pattern did not result in difference between rhLF and natural hLF in any of the employed in vitro and in vivo assay systems. Furthermore, various preclinical toxicity studies and a Phase I clinical study revealed that rhLF is safe and well tolerated. Taken together, transgenic cows are a valuable platform for large-scale production of rhLF for application in human healthcare.UBL - phd migration 201
