Clonal selection of high producing, stably transfected HEK293 cell lines utilizing modified, high-throughput FACS screening

• Published in: Journal of chemical technology and biotechnology (1986) Vol. 86; no. 7; pp. 935 - 941
• Main Authors: Song, Michael, Raphaelli, Kristin, Jones, Martina L., Aliabadi-Zadeh, Khosrow, Leung, Kar Man, Crowley, David, Hughes, Benjamin, Mahler, Stephen, Gray, Peter P., Huang, Edwin P., Chin, David Y.
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.07.2011
• Subjects: cold capture; FACS; HEK-293; monoclonal antibody; stable transfection
• ISSN: 0268-2575; 1097-4660; 1097-4660
• DOI: 10.1002/jctb.2618

BACKGROUND: Human embryonic kidney‐293 (HEK‐293) cells are commonly used as a transient expression host but their application in stable therapeutic protein production is limited. This is presumably due to the absence of a suitable amplifiable expression system and hence limited protein output compared with other mammalian cells such as Chinese hamster ovary cells. This paper describes a rapid clonal selection method for isolating HEK293 cell lines with high specific productivity, for a non‐amplifiable expression system, to achieve high‐level, scalable expression of recombinant antibodies. RESULTS: Flow cytometry utilizing cold capture of secreted protein on the cell surface was applied to isolate high expressing clones from a stable antibiotic resistant pool. The top three isolated clones showed a five‐ to seven‐fold improvement in volumetric outputs compared with the initial resistant pool (∼20 mg L−1) under batch conditions. In fed‐batch conditions using commercially available hydrolysate supplements, the final titre was further increased to 500–600 mg L−1 in shaker flasks. One clone was scaled up to 25 L bag production using a similar hydrolysate feeding regime. The antibody titre reached 655 mg L−1, and 12 g of antibody was recovered after purification, demonstrating scalability of the process. The process of clonal selection through to fed‐batch production of gram quantities was completed within 4 months. CONCLUSION: HEK‐293 cells can be used as a stable host for the production of biopharmaceuticals, producing gram quantities of recombinant proteins for preclinical development. Copyright © 2011 Society of Chemical Industry