Historical reflections on cell culture engineering

Lubiniecki, Anthony S.

doi:10.1007/978-94-011-4786-6_15

Cited by 9 publications

(12 citation statements)

References 6 publications

(3 reference statements)

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“…CHO cells are very robust in a number of culture conditions, have been used for the past 40 years, and therefore are very well characterized. A large number of proteins have been produced on CHO-based systems, such as tPA, Factor VIII, and interferon-γ (reviewed in ref 28), and there are many different strategies currently employed that involve the use of metabolic engineering in order to design a system that will incorporate the robust CHO nature with increased cell proliferation and the use of serum-and/or protein-free media. Such systems include the development of "super-CHO" that expresses IGF-1 and transferrin and has the ability to grow in totally protein-free media (29); "veggie-CHO", a cell line that grows in serum-free media in the absence of transferrin and IGF-1 that produces the recombinant protein Flt-3L (30); the multicistronic CHO cell lines that incorporate the p21-, p27-or p53-containing tetracyclinerepressible expression vectors or the p27-bcl XL -tricistronic system or the lac switch system for inducing p21 in NS0 and CHO cell lines, which all aim to increase cell proliferation, productivity, and decrease cell death (22,23,(31)(32)(33)(34).…”

Section: Discussionmentioning

confidence: 99%

Regulation of Cell Proliferation and Apoptosis in CHO-K1 Cells by the Coexpression of c-Myc and Bcl-2

Ifandi

Al‐Rubeai

2008

Biotechnol Progress

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Proliferation and cell death are regarded as key targets for the optimization of animal cell culture processes and for the maximization of product yield. Although chemical and physical factors are vitally important, of primary interest is the utilization of genetic engineering to regulate cellular processes. CHO cells were first genetically modified to enhance proliferation rate in both suspension and monolayer cultures. Under the constitutive control of c-myc overexpression the CHO cultures showed an increase in growth rate and maximum cell number accompanied by a similar decrease in specific glucose consumption rate. Although the c-myc transfected cell line exhibited apoptosis at much lower rates than is widely reported and associated with the overexpression of c-Myc, it was nevertheless apparent that c-Myc was responsible for the induction of higher apoptotic rates when compared with the control cell line. Hence, the anti-apoptotic gene bcl-2 was also used to transfect the c-Myc CHO cell line, to reduce cell death. Overexpression of both oncoproteins resulted in a cell line that exhibited higher proliferation rates and maximum cell numbers, with a decrease in apoptosis when compared to the parental cell line. In conclusion, it was shown that Bcl-2 protein overexpression specifically abrogates c-Myc-induced apoptosis without affecting the c-Myc mitogenic function.

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Section: Discussionmentioning

confidence: 99%

Regulation of Cell Proliferation and Apoptosis in CHO-K1 Cells by the Coexpression of c-Myc and Bcl-2

Ifandi

Al‐Rubeai

2008

Biotechnol Progress

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“…1,2 However, despite recent successes in developing stable cell lines, media and operating conditions. 1,3,4 CHO cell culture often suffers from poorly understood instability and perturbation issues. This probably originates from variability in raw materials, cell inoculums, and microenvironments within the bioreactor, etc.…”

Section: Introductionmentioning

confidence: 99%

Dielectric spectroscopy‐based estimation ofVCDinCHOcell culture

Lee

Carvell

Brorson

et al. 2014

J of Chemical Tech & Biotech

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BACKGROUND In mammalian cell culture processes, viable cell density (VCD) is one of the most crucial parameters for monitoring of the current status of cell growth and protein production. Among the various real‐time monitoring tools available for VCD in Chinese hamster ovary (CHO) cell culture, dielectric spectroscopy is one of the more reliable due to its simplicity, robustness and accuracy. These attributes enable efficient monitoring and control of the corresponding processes. However, one of the major drawbacks of dielectric spectroscopy is frequent deterioration of accuracy during the late‐growth phase of CHO cell culture. This can be caused by abrupt changes in the cell physiology, as well as environmental conditions. RESULTS In this study, various kinds of chemometric tools were employed to understand the spectral dynamics of dielectric spectroscopy during extended CHO cell culture, including different cell growth phases. Then, the performance of different multivariate regression models were compared with conventional Cole‐Cole equation‐based approaches. The models were compared in their ability to estimate VCD in CHO cell culture from dielectric spectra from several batches of bioreactor operations. Multivariate analysis of dielectric spectral datasets clearly revealed the time‐varying evolution of spectral dynamics during the transition between cell growth phases. The best prediction performance from the dielectric spectroscopy was realized using a regression model based on locally‐weighted partial least squares (LWPLS). This estimation model best compensated for spectral dynamics observed during the different cell growth phases. CONCLUSION Dielectric spectroscopy combined with LWPLS allows achievement of optimal and stable estimation of VCD during CHO cell culture, regardless of inherent differences in cell growth phases. © 2014 Society of Chemical Industry

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“…Since then, the use of primary cell substrates, such as primary chicken embryo fibroblasts (CEFs), has greatly facilitated vaccine manufacturing (e.g. measles, and mumps) [11]. Primary cells were derived directly from an animal source and were not stored-or to a limited extent-as cell banks.…”

Section: Evolution Of Vaccine Production Techniquesmentioning

confidence: 99%