Active hypothermic growth : a novel means for increasing total recombinant protein production by CHO cells

Recombinant human glycoproteins produced by Chinese Hamster Ovary (CHO) cells are an important class of therapeutic molecules and investigating means of improving the production rate and product quality of these glycoproteins is therefore of great interest. Culturing CHO cells under mild hypothermia (30-33 ⁰C) leads to growth arrest in the G₀/G₁ phase of the cell cycle and, in some cases, causes an increase in specific productivity of recombinant protein, as was shown here for the model CHO cell line producing human interferon-gamma (IFN-[gamma]). Controlled proliferation, achieved by inducing growth arrest in the G₀/G₁ phase by chemical, environmental or genetic means, is commonly used to increase CHO specific productivity and thus there is speculation that enhanced hypothermic productivity is due to growth arrest. However, it was proven here that the positive effect of hypothermia on recombinant protein production is due to elevated IFN-[gamma] mRNA levels instead. At both 32 ⁰C and 37 ⁰C, specific productivity is growth-associated, increasing as the percentage of cells in the S phase increased, demonstrating that a cell line can be both a growth-associated producer and have enhanced productivity under hypothermic conditions. It was hypothesized that the best production platform would be cells actively growing at low temperature and this was proven to be the case using two different methods, namely growth factor supplementation and selection of cells capable of hypothermic growth. Both methods gave multi-fold increases in total IFN-y production compared to the 32 ⁰C and 37 ⁰C controls, thereby validating the novel culture strategy of active hypothermic growth.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Chemical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2005

Author dc:creator

• Fox, Stephen Richard

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/1721.1/32333
• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Identifier URI

http://dspace.mit.edu/handle/1721.1/32333

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/32333