Enhancing Production of Recombinant BMP‐2 in Mammalian Cell Culture

Abstract

BackgroundBone morphogenetic proteins (BMPs) have been used successfully for bone repair; however recombinant BMPs are produced at relatively low yields in mammalian cells. Literature suggests the BMP pro‐domain may be involved in folding, stability, and secretion of the mature protein.ObjectiveInvestigate inhibition of pro‐domain cleavage on recombinant BMP‐2 production.MethodsCHO cells transfected with the hBMP‐2 gene were cultured in the presence of various concentrations of the pro‐protein convertase inhibitor IND‐1 in 24 and 72hr multi‐well, and two‐month bioreactor cultures. Mature and proBMP‐2 secretion was measured by enzyme‐linked immunosorbent assay and characterized by Western blot. BMP activity was determined by C2C12 bioassay. Cytotoxicity was determined by lactate dehydrogenase assay and cell viability counts.ResultsIND‐1 significantly enhanced secretion of both pro‐ and mature recombinant human BMP‐2 (rhBMP‐2) in short and long term cultures, without negative effects on cell growth or viability. The rhBMP‐2 was biologically active. ProBMP‐2 could be converted by enzymatic treatment into mature BMP‐2.ConclusionsAddition of IND‐1 in cell culture medium increased rhBMP‐2 production in CHO‐BMP2 cells and is a simple, but effective way to enhance the production of active rhBMP‐2 in such production systems.GrantOral Surgery Foundation.