title: Genetic engineering of α2,6-sialyltransferase in recombinant CHO cells and its effects on the sialylation of recombinant interferon-γ.
abstract: The CHO cell line has achieved considerable commercial importance as a vehicle for the production of human therapeutic proteins, but is known to lack a functional copy of the gene coding for α2,6-sialyltransferase (EC 2.4.99.1). The cDNA for rat α2,6-ST was expressed in a recombinant CHO cell line making interferon-γ, using a novel in vitro amplification vector. The enzyme was expressed efficiently, and resulted in up to 60% of the total sialic acids on interferon-γ being linked in the α2,6-conformation. This sialic acid linkage distribution was more akin to that seen in natural human glycoproteins. In the most successful cell clones, expression of α2,6-sialyltransferase improved the overall level of sialylation by up to 56%, and had no adverse effects on cell growth, IFN-γ productivity or other aspects of IFN-γ glycosylation. These experiments demonstrate how the glycosylation machinery of rodent cells can be genetically manipulated to replicate human tissues.
authors.affiliation: Department of Biological & Technological Research, San Raffaele Scientific Institute, Milan, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Monaco
authors.forename: A
authors.initials: A
authors.lastname: Marc
authors.forename: A
authors.initials: A
authors.lastname: Eon-Duval
authors.forename: G
authors.initials: G
authors.lastname: Acerbis
authors.forename: G
authors.initials: G
authors.lastname: Distefano
authors.forename: D
authors.initials: D
authors.lastname: Lamotte
authors.forename: J M
authors.initials: JM
authors.lastname: Engasser
authors.forename: M
authors.initials: M
authors.lastname: Soria
authors.forename: N
authors.initials: N
authors.lastname: Jenkins