Protein expression and glycosylation in CHO cells

A successful mammalian cell culture process depends on sufficient expression and correct glycosylation of the recombinant product. Low product titer and inconsistent protein glycosylation constitute two major problems frequently encountered in biopharmaceutical production. Using Chinese Hamster Ovary (CHO) cells expressing recombinant human interferon-gamma (IFN-y) as the model system, this thesis investigated strategies that can potentially enhance heterologous protein expression or control the extent of protein glycosylation. There has been considerable interest in developing culture strategies to improve productivity in mammalian cell lines by limiting the cellular growth rate. An initial investigation demonstrated the difficulty in obtaining growth-arrested cells that are robust and productive. In the following study, a method to rapidly generate and isolate CHO cells that exhibit enhanced potential for use in proliferation-controlled bioprocesses was developed. By combining bicistronic retroviral technology with an appropriate selection strategy, a subpopulation was isolated from a heterogeneous cell population. To evaluate the effectiveness of this screening process, the performance of this selected subpopulation was compared with that of the original population under identical growth-arresting conditions. Important differences were observed: by contrast to the original population, the selected cells maintained consistently high viabilities and continued to stably express recombinant proteins after being growth-arrested for two weeks. Asparagine-linked (N-linked) glycosylation can significantly impact critical properties of human therapeutic proteins.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Chemical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2001

Author dc:creator

• Yuk, Inn Huam Yvonne.

Advisor dc:contributor.advisor

• Daniel I.C. Wang.

• Chemical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/8201

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/8201