Genetic engineering of α2,6-sialyltransferase in recombinant CHO cells and its effects on the sialylation of recombinant interferon-γ

✍ Scribed by Lucia Monaco; Annie Marc; Alex Eon-Duval; Giulia Acerbis; Gianfranco Distefano; Damien Lamotte; Jean-Marc Engasser; Marco Soria; Nigel Jenkins

• Publisher: Springer
• Year: 1996
• Tongue: English
• Weight: 655 KB
• Volume: 22
• Category: Article
• ISSN: 0920-9069
• DOI: 10.1007/bf00353939

✦ Synopsis

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.