1
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Patil AA, Bhor SA, Rhee WJ. Cell death in culture: Molecular mechanisms, detections, and inhibition strategies. J IND ENG CHEM 2020. [DOI: 10.1016/j.jiec.2020.08.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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2
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Henry MN, MacDonald MA, Orellana CA, Gray PP, Gillard M, Baker K, Nielsen LK, Marcellin E, Mahler S, Martínez VS. Attenuating apoptosis in Chinese hamster ovary cells for improved biopharmaceutical production. Biotechnol Bioeng 2020; 117:1187-1203. [DOI: 10.1002/bit.27269] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 11/25/2019] [Accepted: 01/04/2020] [Indexed: 12/11/2022]
Affiliation(s)
- Matthew N. Henry
- Australian Institute for Bioengineering and Nanotechnology (AIBN) The University of Queensland Brisbane Queensland Australia
| | - Michael A. MacDonald
- ARC Training Centre for Biopharmaceutical Innovation (CBI) Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland Brisbane Queensland Australia
| | - Camila A. Orellana
- Australian Institute for Bioengineering and Nanotechnology (AIBN) The University of Queensland Brisbane Queensland Australia
| | - Peter P. Gray
- Australian Institute for Bioengineering and Nanotechnology (AIBN) The University of Queensland Brisbane Queensland Australia
| | - Marianne Gillard
- Australian Institute for Bioengineering and Nanotechnology (AIBN) The University of Queensland Brisbane Queensland Australia
| | - Kym Baker
- ARC Training Centre for Biopharmaceutical Innovation (CBI) Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland Brisbane Queensland Australia
- Patheon Biologics—A Part of Thermo Fisher Scientific Brisbane Queensland Australia
| | - Lars K. Nielsen
- Australian Institute for Bioengineering and Nanotechnology (AIBN) The University of Queensland Brisbane Queensland Australia
- ARC Training Centre for Biopharmaceutical Innovation (CBI) Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland Brisbane Queensland Australia
- Metabolomics Australia The University of Queensland Brisbane Queensland Australia
- The Novo Nordisk Foundation Center for Biosustainability Technical University of Denmark Kgs. Lyngby Denmark
| | - Esteban Marcellin
- Australian Institute for Bioengineering and Nanotechnology (AIBN) The University of Queensland Brisbane Queensland Australia
- ARC Training Centre for Biopharmaceutical Innovation (CBI) Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland Brisbane Queensland Australia
- Metabolomics Australia The University of Queensland Brisbane Queensland Australia
| | - Stephen Mahler
- ARC Training Centre for Biopharmaceutical Innovation (CBI) Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland Brisbane Queensland Australia
| | - Verónica S. Martínez
- ARC Training Centre for Biopharmaceutical Innovation (CBI) Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland Brisbane Queensland Australia
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3
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Zhang X, Han L, Zong H, Ding K, Yuan Y, Bai J, Zhou Y, Zhang B, Zhu J. Enhanced production of anti-PD1 antibody in CHO cells through transient co-transfection with anti-apoptotic genes Bcl-x L and Mcl-1. Bioprocess Biosyst Eng 2018; 41:633-640. [PMID: 29368032 DOI: 10.1007/s00449-018-1898-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 01/15/2018] [Indexed: 12/17/2022]
Abstract
Apoptosis has a negative impact on the cell survival state during cell cultivation. To optimize mammalian cell culture for production of biopharmaceuticals, one of the important approaches is to extend cell life through over-expression of anti-apoptotic genes. Here, we reported a cost-effective process to enhance cell survival and production of an antibody through transient co-transfection with anti-apoptotic genes Bcl-x L or Mcl-1 in Chinese hamster ovary (CHO) cells with polyethylenimine (PEI). Under the optimal conditions, it showed reduced levels of apoptosis and improved cell viability after co-transfected with Bcl-x L or Mcl-1. The overall production yield of the antibody anti-PD1 increased approximately 82% in CHO cells co-transfected with Bcl-x L , and 34% in CHO cells co-transfected with Mcl-1. This work provides an effective way to increase viability of host cells through delaying apoptosis onset, thus, raise production yield of biopharmaceuticals without the process of generating stable cell lines and subsequent screening.
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Affiliation(s)
- Xinyu Zhang
- Engineering Research Center of Cell and Therapeutic Antibody, Ministry of Education; School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, People's Republic of China
| | - Lei Han
- Engineering Research Center of Cell and Therapeutic Antibody, Ministry of Education; School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, People's Republic of China
| | - Huifang Zong
- Engineering Research Center of Cell and Therapeutic Antibody, Ministry of Education; School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, People's Republic of China
| | - Kai Ding
- Engineering Research Center of Cell and Therapeutic Antibody, Ministry of Education; School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, People's Republic of China
| | - Yuan Yuan
- Engineering Research Center of Cell and Therapeutic Antibody, Ministry of Education; School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, People's Republic of China
| | - Jingyi Bai
- Engineering Research Center of Cell and Therapeutic Antibody, Ministry of Education; School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, People's Republic of China
| | - Yuexian Zhou
- Engineering Research Center of Cell and Therapeutic Antibody, Ministry of Education; School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, People's Republic of China
| | - Baohong Zhang
- Engineering Research Center of Cell and Therapeutic Antibody, Ministry of Education; School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, People's Republic of China.
| | - Jianwei Zhu
- Engineering Research Center of Cell and Therapeutic Antibody, Ministry of Education; School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, People's Republic of China.
- Jecho Laboratories, Inc. 7320 Executive Way, Frederick, MD, 21704, USA.
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4
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Beaumatin F, El Dhaybi M, Lasserre JP, Salin B, Moyer MP, Verdier M, Manon S, Priault M. N52 monodeamidated Bcl‑xL shows impaired oncogenic properties in vivo and in vitro. Oncotarget 2017; 7:17129-43. [PMID: 26958941 PMCID: PMC4941376 DOI: 10.18632/oncotarget.7938] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 01/31/2016] [Indexed: 12/19/2022] Open
Abstract
Bcl-xL is a member of the Bcl-2 family, playing a critical role in the survival of tumor cells. Here, we show that Bcl-xL oncogenic function can be uncoupled from its anti-apoptotic activity when it is regulated by the post-translational deamidation of its Asn52. Bcl-xL activity can be regulated by post-translational modifications: deamidation of Asn52 and 66 into Asp residues was reported to occur exclusively in response to DNA damage, and to cripple its anti-apoptotic activity. Our work reports for the first time the spontaneous occurrence of monodeamidated Asp52Bcl-xL in control conditions, in vivo and in vitro. In the normal and cancer cell lines tested, no less than 30% and up to 56% of Bcl-xL was singly deamidated on Asn52. Functional analyses revealed that singly deamidated Bcl-xL retains anti-apoptotic functions, and exhibits enhanced autophagic activity while harboring impaired clonogenic and tumorigenic properties compared to native Bcl-xL. Additionally, Asp52Bcl-xL remains phosphorylatable, and thus is still an eligible target of anti-neoplasic agents. Altogether our results complement the existing data on Bcl-xL deamidation: they challenge the common acceptance that Asn52 and Asn66 are equally eligible for deamidation, and provide a valuable improvement of our knowledge on the regulation of Bcl-xLoncogenic functions by deamidation.
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Affiliation(s)
- Florian Beaumatin
- CNRS, Institut de Biochimie et de Génétique Cellulaires, UMR5095, 33077 Bordeaux, France.,Université Bordeaux Ségalen, Institut de Biochimie et de Génétique Cellulaires, UMR5095, 33077 Bordeaux, France
| | - Mohamad El Dhaybi
- CNRS, Institut de Biochimie et de Génétique Cellulaires, UMR5095, 33077 Bordeaux, France.,Université Bordeaux Ségalen, Institut de Biochimie et de Génétique Cellulaires, UMR5095, 33077 Bordeaux, France.,EA 3842, Homéostasie Cellulaire et Pathologies, Université de Limoges, 87025 Limoges Cedex, France
| | - Jean-Paul Lasserre
- CNRS, Institut de Biochimie et de Génétique Cellulaires, UMR5095, 33077 Bordeaux, France.,Université Bordeaux Ségalen, Institut de Biochimie et de Génétique Cellulaires, UMR5095, 33077 Bordeaux, France
| | - Bénédicte Salin
- CNRS, Institut de Biochimie et de Génétique Cellulaires, UMR5095, 33077 Bordeaux, France.,Université Bordeaux Ségalen, Institut de Biochimie et de Génétique Cellulaires, UMR5095, 33077 Bordeaux, France
| | | | - Mireille Verdier
- EA 3842, Homéostasie Cellulaire et Pathologies, Université de Limoges, 87025 Limoges Cedex, France
| | - Stéphen Manon
- CNRS, Institut de Biochimie et de Génétique Cellulaires, UMR5095, 33077 Bordeaux, France.,Université Bordeaux Ségalen, Institut de Biochimie et de Génétique Cellulaires, UMR5095, 33077 Bordeaux, France
| | - Muriel Priault
- CNRS, Institut de Biochimie et de Génétique Cellulaires, UMR5095, 33077 Bordeaux, France.,Université Bordeaux Ségalen, Institut de Biochimie et de Génétique Cellulaires, UMR5095, 33077 Bordeaux, France
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5
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Gulce Iz S, Inevi MA, Metiner PS, Tamis DA, Kisbet N. A BioDesign Approach to Obtain High Yields of Biosimilars by Anti-apoptotic Cell Engineering: a Case Study to Increase the Production Yield of Anti-TNF Alpha Producing Recombinant CHO Cells. Appl Biochem Biotechnol 2017; 184:303-322. [PMID: 28685239 DOI: 10.1007/s12010-017-2540-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 06/14/2017] [Indexed: 10/19/2022]
Abstract
Recent developments in medical biotechnology have facilitated to enhance the production of monoclonal antibodies (mAbs) and recombinant proteins in mammalian cells. Human mAbs for clinical applications have focused on three areas, particularly cancer, immunological disorders, and infectious diseases. Tumor necrosis factor alpha (TNF-α), which has both proinflammatory and immunoregulatory functions, is an important target in biopharmaceutical industry. In this study, a humanized anti-TNF-α mAb producing stable CHO cell line which produces a biosimilar of Humira (adalimumab) was used. Adalimumab is a fully human anti-TNF mAb among the top-selling mAb products in recent years as a biosimilar. Products from mammalian cell bioprocesses are a derivative of cell viability and metabolism, which is mainly disrupted by cell death in bioreactors. Thus, different strategies are used to increase the product yield. Suppression of apoptosis, also called anti-apoptotic cell engineering, is the most remarkable strategy to enhance lifetime of cells for a longer production period. In fact, using anti-apoptotic cell engineering as a BioDesign approach was inspired by nature; nature gives prolonged life span to some cells like stem cells, tumor cells, and memory B and T cells, and researchers have been using this strategy for different purposes. In this study, as a biomimicry approach, anti-apoptotic cell engineering was used to increase the anti-TNF-α mAb production from the humanized anti-TNF-α mAb producing stable CHO cell line by Bcl-xL anti-apoptotic protein. It was shown that transient transfection of CHO cells by the Bcl-xL anti-apoptotic protein expressing plasmid prolonged the cell survival rate and protected cells from apoptosis. The transient expression of Bcl-xL using CHO cells enhanced the anti-TNF-α production. The production of anti-TNF-α in CHO cells was increased up to 215 mg/L with an increase of 160% after cells were transfected with Bcl-xL expressing plasmid with polyethylenimine (PEI) reagent at the ratio of 1:6 (DNA:PEI). In conclusion, the anti-apoptotic efficacy of the Bcl-xL expressing plasmid in humanized anti-TNF-α MAb producing stable CHO cells is compatible with curative effect for high efficiency recombinant protein production. Thus, this model can be used for large-scale production of biosimilars through transient Bcl-xL gene expression as a cost-effective method.
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Affiliation(s)
- Sultan Gulce Iz
- Department of Bioengineering, Faculty of Engineering, Ege University, 35100, Izmir, Bornova, Turkey.
| | - Muge Anil Inevi
- Department of Bioengineering, Faculty of Engineering, Ege University, 35100, Izmir, Bornova, Turkey
- Department of Biotechnology and Bioengineering, Izmir Institute of Technology, 35430, Izmir, Urla, Turkey
| | - Pelin Saglam Metiner
- Department of Bioengineering, Faculty of Engineering, Ege University, 35100, Izmir, Bornova, Turkey
| | - Duygu Ayyildiz Tamis
- Department of Bioengineering, Faculty of Engineering, Ege University, 35100, Izmir, Bornova, Turkey
- Turgut Ilaclari A.S, 34394, Istanbul, Besiktas, Turkey
| | - Nazli Kisbet
- Department of Bioengineering, Faculty of Engineering, Ege University, 35100, Izmir, Bornova, Turkey
- GlaxoSmithKline, 34394, Istanbul, Besiktas, Turkey
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6
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Priya P, Maity A, Ghosh Dastidar S. The long unstructured region of Bcl-xl modulates its structural dynamics. Proteins 2017; 85:1567-1579. [PMID: 28486788 DOI: 10.1002/prot.25316] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2017] [Revised: 04/28/2017] [Accepted: 05/02/2017] [Indexed: 01/22/2023]
Abstract
Bcl-xl protein has a long unstructured loop attached to its structured region which joins two helices. The necessity to have this unstructured segment in Bcl-xl is not yet well understood. To what extent the unstructured segment can influence the dynamics of the structured region of protein, with potential to influence the function, has been investigated in this work. Molecular dynamics simulation and principal component analysis show how the loop affects the internal motions of the protein, particularly its ligand binding pocket. Generally an unstructured region in the structure would promote flexibility resulting entropic stability but in contrary, here it narrows down the conformational space of the structured region of protein that could be hypothesized to impact the functional precision. Effects of the loop propagate to the binding pocket through structural rearrangements of polar side chains. The immediate suspicion of possible impact of phosphorylation to modulate the function of the protein is proven to be a fact, as the phosphorylated S49 and S62 located on the large unstructured region are seen to perturb the electrostatic network of the structure; an observation that validates and clarifies the role of loop as a modulator through biophysical and biochemical mechanisms. Proteins 2017; 85:1567-1579. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Prerna Priya
- Bioinformatics Centre, Bose Institute, P-1/12 C.I.T Scheme VII M, Kolkata, 700054, India
| | - Atanu Maity
- Bioinformatics Centre, Bose Institute, P-1/12 C.I.T Scheme VII M, Kolkata, 700054, India
| | - Shubhra Ghosh Dastidar
- Bioinformatics Centre, Bose Institute, P-1/12 C.I.T Scheme VII M, Kolkata, 700054, India
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7
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Abstract
Chinese hamster ovary (CHO) cells represent the predominant platform in biopharmaceutical industry for the production of recombinant biotherapeutic proteins, especially glycoproteins. These glycoproteins include oligosaccharide or glycan attachments that represent one of the principal components dictating product quality. Especially important are the N-glycan attachments present on many recombinant glycoproteins of commercial interest. Furthermore, altering the glycan composition can be used to modulate the production quality of a recombinant biotherapeutic from CHO and other mammalian hosts. This review first describes the glycosylation network in mammalian cells and compares the glycosylation patterns between CHO and human cells. Next genetic strategies used in CHO cells to modulate the sialylation patterns through overexpression of sialyltransfereases and other glycosyltransferases are summarized. In addition, other approaches to alter sialylation including manipulation of sialic acid biosynthetic pathways and inhibition of sialidases are described. Finally, this review also covers other strategies such as the glycosylation site insertion and manipulation of glycan heterogeneity to produce desired glycoforms for diverse biotechnology applications.
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Affiliation(s)
- Qiong Wang
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, 3400 N. Charles St., 220 Maryland Hall, Baltimore, MD, 21218, USA
| | - Bojiao Yin
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, 3400 N. Charles St., 220 Maryland Hall, Baltimore, MD, 21218, USA
| | - Cheng-Yu Chung
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, 3400 N. Charles St., 220 Maryland Hall, Baltimore, MD, 21218, USA
| | - Michael J Betenbaugh
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, 3400 N. Charles St., 220 Maryland Hall, Baltimore, MD, 21218, USA.
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8
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Affiliation(s)
- Jennifer Pfizenmaier
- University of Stuttgart; Institute of Biochemical Engineering; Allmandring 31 70569 Stuttgart Germany
| | - Ralf Takors
- University of Stuttgart; Institute of Biochemical Engineering; Allmandring 31 70569 Stuttgart Germany
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9
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Current state and recent advances in biopharmaceutical production in Escherichia coli, yeasts and mammalian cells. J Ind Microbiol Biotechnol 2013; 40:257-74. [PMID: 23385853 DOI: 10.1007/s10295-013-1235-0] [Citation(s) in RCA: 139] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Accepted: 01/22/2013] [Indexed: 12/28/2022]
Abstract
Almost all of the 200 or so approved biopharmaceuticals have been produced in one of three host systems: the bacterium Escherichia coli, yeasts (Saccharomyces cerevisiae, Pichia pastoris) and mammalian cells. We describe the most widely used methods for the expression of recombinant proteins in the cytoplasm or periplasm of E. coli, as well as strategies for secreting the product to the growth medium. Recombinant expression in E. coli influences the cell physiology and triggers a stress response, which has to be considered in process development. Increased expression of a functional protein can be achieved by optimizing the gene, plasmid, host cell, and fermentation process. Relevant properties of two yeast expression systems, S. cerevisiae and P. pastoris, are summarized. Optimization of expression in S. cerevisiae has focused mainly on increasing the secretion, which is otherwise limiting. P. pastoris was recently approved as a host for biopharmaceutical production for the first time. It enables high-level protein production and secretion. Additionally, genetic engineering has resulted in its ability to produce recombinant proteins with humanized glycosylation patterns. Several mammalian cell lines of either rodent or human origin are also used in biopharmaceutical production. Optimization of their expression has focused on clonal selection, interference with epigenetic factors and genetic engineering. Systemic optimization approaches are applied to all cell expression systems. They feature parallel high-throughput techniques, such as DNA microarray, next-generation sequencing and proteomics, and enable simultaneous monitoring of multiple parameters. Systemic approaches, together with technological advances such as disposable bioreactors and microbioreactors, are expected to lead to increased quality and quantity of biopharmaceuticals, as well as to reduced product development times.
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10
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Baycin-Hizal D, Tabb DL, Chaerkady R, Chen L, Lewis NE, Nagarajan H, Sarkaria V, Kumar A, Wolozny D, Colao J, Jacobson E, Tian Y, O'Meally RN, Krag SS, Cole RN, Palsson BO, Zhang H, Betenbaugh M. Proteomic analysis of Chinese hamster ovary cells. J Proteome Res 2012; 11:5265-76. [PMID: 22971049 DOI: 10.1021/pr300476w] [Citation(s) in RCA: 135] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
To complement the recent genomic sequencing of Chinese hamster ovary (CHO) cells, proteomic analysis was performed on CHO cells including the cellular proteome, secretome, and glycoproteome using tandem mass spectrometry (MS/MS) of multiple fractions obtained from gel electrophoresis, multidimensional liquid chromatography, and solid phase extraction of glycopeptides (SPEG). From the 120 different mass spectrometry analyses generating 682,097 MS/MS spectra, 93,548 unique peptide sequences were identified with at most 0.02 false discovery rate (FDR). A total of 6164 grouped proteins were identified from both glycoproteome and proteome analysis, representing an 8-fold increase in the number of proteins currently identified in the CHO proteome. Furthermore, this is the first proteomic study done using the CHO genome exclusively, which provides for more accurate identification of proteins. From this analysis, the CHO codon frequency was determined and found to be distinct from humans, which will facilitate expression of human proteins in CHO cells. Analysis of the combined proteomic and mRNA data sets indicated the enrichment of a number of pathways including protein processing and apoptosis but depletion of proteins involved in steroid hormone and glycosphingolipid metabolism. Five-hundred four of the detected proteins included N-acetylation modifications, and 1292 different proteins were observed to be N-glycosylated. This first large-scale proteomic analysis will enhance the knowledge base about CHO capabilities for recombinant expression and provide information useful in cell engineering efforts aimed at modifying CHO cellular functions.
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Affiliation(s)
- Deniz Baycin-Hizal
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland, USA
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11
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Majors BS, Chiang GG, Pederson NE, Betenbaugh MJ. Directed evolution of mammalian anti-apoptosis proteins by somatic hypermutation. Protein Eng Des Sel 2011; 25:27-38. [PMID: 22160868 DOI: 10.1093/protein/gzr052] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Recently, researchers have created novel fluorescent proteins by harnessing the somatic hypermutation ability of B cells. In this study, we examined if this approach could be used to evolve a non-fluorescent protein, namely the anti-apoptosis protein Bcl-x(L), using the Ramos B-cell line. After demonstrating that Ramos cells were capable of mutating a heterologous bcl-x(L) transgene, the cells were exposed to multiple rounds of the chemical apoptosis inducer staurosporine followed by rounds of recovery in fresh medium. The engineered B cells expressing Bcl-x(L) exhibited progressively lower increases in apoptosis activation as measured by caspase-3 activity after successive rounds of selective pressure with staurosporine treatment. Within the B-cell genome, a number of mutated bcl-x(L) transgene variants were identified after three rounds of evolution, including a mutation of Bcl-x(L) Asp29 to either Asn or His, in 8 out of 23 evaluated constructs that represented at least five distinct Ramos subpopulations. Subsequently, Chinese hamster ovary (CHO) cells engineered to overexpress the Bcl-x(L) Asp29Asn variant showed enhanced apoptosis resistance against an orthogonal apoptosis insult, Sindbis virus infection, when compared with cells expressing the wild-type Bcl-x(L) protein. These findings provide, to our knowledge, the first demonstration of evolution of a recombinant mammalian protein in a mammalian expression system.
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Affiliation(s)
- Brian S Majors
- Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, 3400 North Charles Street, 221 Maryland Hall, Baltimore, MD 21218-2694, USA
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Rossi DL, Rossi EA, Goldenberg DM, Chang CH. A new mammalian host cell with enhanced survival enables completely serum-free development of high-level protein production cell lines. Biotechnol Prog 2011; 27:766-75. [PMID: 21473000 DOI: 10.1002/btpr.584] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2010] [Revised: 03/04/2011] [Indexed: 11/08/2022]
Abstract
With over 25 monoclonal antibodies (mAbs) currently approved and many more in development, there is considerable interest in gaining improved productivity by increasing cell density and enhancing cell survival of production cell lines. In addition, high costs and growing safety concerns with use of animal products have made the availability of serum-free cell lines more appealing. We elected to transfect the myeloma cell line Sp2/0-Ag14 with Bcl2-EEE, the constitutively active phosphomimetic mutant of Bcl2, for extended cell survival. After adaptation of the initial transfectants to serum-independent growth, a clone with superior growth properties, referred to as SpESF, was isolated and further subjected to iterative rounds of stressful growth over a period of 4 months. The effort resulted in the selection of a promising clone, designated SpESFX-10, which was shown to exhibit robust growth and resist apoptosis induced by sodium butyrate or glutamine deprivation. The advantage of SpESFX-10 as a host for generating mAb-production cell lines was demonstrated by its increased transfection efficiency, culture longevity, and mAb productivity, as well as by the feasibility of accomplishing the entire cell line development process, including transfection, subcloning, and cryopreservation, in the complete absence of serum.
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13
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Dorai H, Ellis D, Keung YS, Campbell M, Zhuang M, Lin C, Betenbaugh MJ. Combining high-throughput screening of caspase activity with anti-apoptosis genes for development of robust CHO production cell lines. Biotechnol Prog 2011; 26:1367-81. [PMID: 20945491 DOI: 10.1002/btpr.426] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
A set of anti-apoptotic genes were over-expressed, either singly or in combination, in an effort to develop robust Chinese Hamster Ovary host cell lines suitable for manufacturing biotherapeutics. High-throughput screening of caspase 3/7 activity enabled a rapid selection of transfectants with reduced caspase activity relative to the host cell line. Transfectants with reduced caspase 3/7 activity were then tested for improved integrated viable cell count (IVCC), a function of peak viable cell density and longevity. The maximal level of improvement in IVCC could be achieved by over-expression of either single anti-apoptotic genes, e.g., Bcl-2Δ (a mutated variant of Bcl-2) or Bcl-XL, or a combination of two or three anti-apoptotic genes, e.g., E1B-19K, Aven, and XIAPΔ. These cell lines yielded higher transient antibody production and a greater number of stable clones with high antibody yields. In a 5 L fed-batch bioreactor system, BΔ31-1, a stable clone expressing Bcl-2Δ, had a product titer that was 180% as compared to an optimal clone (Con-1) from the control cell line. Although lactate accumulated to more than 5 g/L in the control culture, its concentration was reduced in the anti-apoptotic BΔ31-1 cultures to below 1 g/L, confirming our earlier findings that cells over-expressing anti-apoptotic genes consume the lactate that would otherwise accumulate as a by-product in the culture medium. To the best of our knowledge, this is the first study to use the high throughput caspase screening method to identify CHO host cell lines with superior anti-apoptotic characteristics.
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Affiliation(s)
- Haimanti Dorai
- Pharmaceutical Development, Centocor R&D, Radnor, PA 19087, USA.
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14
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Wang Z, Park JH, Park HH, Tan W, Park TH. Enhancement of therapeutic monoclonal antibody production in CHO cells using 30Kc6 gene. Process Biochem 2010. [DOI: 10.1016/j.procbio.2010.03.029] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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15
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Yung CW, Bentley WE, Barbari TA. Diffusion of interleukin-2 from cells overlaid with cytocompatible enzyme-crosslinked gelatin hydrogels. J Biomed Mater Res A 2010; 95:25-32. [DOI: 10.1002/jbm.a.32740] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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16
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Park JH, Park HH, Park TH. Cellular engineering for the high-level production of recombinant proteins in mammalian cell systems. KOREAN J CHEM ENG 2010. [DOI: 10.1007/s11814-010-0278-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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17
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Engineering mammalian cells in bioprocessing - current achievements and future perspectives. Biotechnol Appl Biochem 2010; 55:175-89. [PMID: 20392202 DOI: 10.1042/ba20090363] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Over the past 20 years, we have seen significant improvements in product titres from 50 mg/l to 5-10 g/l, a more than 100-fold increase. The main methods that have been employed to achieve this increase in product titre have been through the manipulation of culture media and process control strategies, such as the optimization of fed-batch processes. An alternative means to increase productivity has been through the engineering of host cells by altering cellular processes. Recombinant DNA technology has been used to over-express or suppress specific genes to endow particular phenotypes. Cellular processes that have been altered in host cells include metabolism, cell cycle, protein secretion and apoptosis. Cell engineering has also been employed to improve post-translational modifications such as glycosylation. In this article, an overview of the main cell engineering strategies previously employed and the impact of these strategies are presented. Many of these strategies focus on engineering cell lines with more efficient carbon metabolism towards reducing waste metabolites, achieving a biphasic production system by engineering cell cycle control, increasing protein secretion by targeting specific endoplasmic reticulum stress chaperones, delaying cell death by targeting anti-apoptosis genes, and engineering glycosylation by enhancing recombinant protein sialylation and antibody glycosylation. Future perspectives for host cell engineering, and possible areas of research, are also discussed in this review.
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Majors BS, Betenbaugh MJ, Pederson NE, Chiang GG. Mcl-1 overexpression leads to higher viabilities and increased production of humanized monoclonal antibody in Chinese hamster ovary cells. Biotechnol Prog 2009; 25:1161-8. [PMID: 19551877 DOI: 10.1002/btpr.192] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Bioreactor stresses, including nutrient deprivation, shear stress, and byproduct accumulation can cause apoptosis, leading to lower recombinant protein yields and increased costs in downstream processing. Although cell engineering strategies utilizing the overexpression of antiapoptotic Bcl-2 family proteins such as Bcl-2 and Bcl-x(L) potently inhibit apoptosis, no studies have examined the use of the Bcl-2 family protein, Mcl-1, in commercial mammalian cell culture processes. Here, we overexpress both the wild type Mcl-1 protein and a Mcl-1 mutant protein that is not degraded by the proteasome in a serum-free Chinese hamster ovary (CHO) cell line producing a therapeutic antibody. The expression of Mcl-1 led to increased viabilities in fed-batch culture, with cell lines expressing the Mcl-1 mutant maintaining approximately 90% viability after 14 days when compared with 65% for control cells. In addition to enhanced culture viability, Mcl-1-expressing cell lines were isolated that consistently showed increases in antibody production of 20-35% when compared with control cultures. The quality of the antibody product was not affected in the Mcl-1-expressing cell lines, and Mcl-1-expressing cells exhibited 3-fold lower caspase-3 activation when compared with the control cell lines. Altogether, the expression of Mcl-1 represents a promising alternative cell engineering strategy to delay apoptosis and increase recombinant protein production in CHO cells.
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Affiliation(s)
- Brian S Majors
- Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, Baltimore, MD 21218, USA
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Dorai H, Kyung YS, Ellis D, Kinney C, Lin C, Jan D, Moore G, Betenbaugh MJ. Expression of anti-apoptosis genes alters lactate metabolism of Chinese Hamster Ovary cells in culture. Biotechnol Bioeng 2009; 103:592-608. [DOI: 10.1002/bit.22269] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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O'Connor S, Li E, Majors BS, He L, Placone J, Baycin D, Betenbaugh MJ, Hristova K. Increased expression of the integral membrane protein ErbB2 in Chinese hamster ovary cells expressing the anti-apoptotic gene Bcl-xL. Protein Expr Purif 2009; 67:41-7. [PMID: 19376231 DOI: 10.1016/j.pep.2009.04.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2009] [Revised: 04/06/2009] [Accepted: 04/09/2009] [Indexed: 11/18/2022]
Abstract
Receptor tyrosine kinases (RTKs) are the second largest family of membrane receptors and play a key role in the regulation of vital cellular processes, such as control of cell growth, differentiation, metabolism, and migration. The production of whole-length RTKs in large quantities for biophysical or structural characterization, however, is a challenge. In this study, a cell engineering strategy using the anti-apoptotic Bcl-2 family protein, Bcl-x(L), was tested as a potential method for increasing stable expression levels of a recombinant RTK membrane protein in Chinese hamster ovary (CHO) cells. Wild-type and CHO cells stably overexpressing heterologous Bcl-x(L) were transformed with the gene for a model RTK membrane protein, ErbB2, on a plasmid also containing the Zeocin resistance gene. While CHO cells exhibited a gradual decrease in expression with passaging, CHO-bcl-x(L) cells offered an increased and sustained level of ErbB2 expression following continuous passaging over more than 33 days in culture. The increased ErbB2 expression in CHO-bcl-x(L) cells was evident both in stable transfected pools and in clonal isolates, and demonstrated both in Western blot analysis and flow cytometry. Furthermore, the sustained high-level protein expression in CHO-bcl-x(L) cells does not alter the correct membrane localization of the ErbB2 protein. Our results demonstrate that cellular engineering, specifically anti-apoptosis engineering, can provide increased and stable ErbB2 membrane protein expression in mammalian cells. This approach may also be useful for other membrane proteins in which large quantities are needed for biophysical and structural studies.
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Affiliation(s)
- Shannon O'Connor
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
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Nivitchanyong T, Tsai YC, Betenbaugh MJ, Oyler GA. An improved in vitro and in vivo Sindbis virus expression system through host and virus engineering. Virus Res 2009; 141:1-12. [PMID: 19200810 DOI: 10.1016/j.virusres.2008.12.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2008] [Revised: 12/06/2008] [Accepted: 12/12/2008] [Indexed: 10/21/2022]
Abstract
The Sindbis viral expression system enables the rapid production of high levels of recombinant protein in mammalian cells; however, this expression is typically limited to transient production due to the cytotoxicity of the virus. Limiting the lethality inherent in the Sindbis virus vector in order to enable long term, sustained expression of recombinant proteins may be possible. In this study, modifications to virus and host have been combined in order to reduce the cytopathic effects. Non-cytopathic replication competent viruses of two Sindbis viral strains, TE and 633, were developed using a non-structural protein (nsP) P726S point mutation in order to obtain persistent heterologous gene expression in infected Baby Hamster Kidney (BHK) cells and Chinese Hamster Ovary (CHO) cells. Cells infected with the P726S variant viruses were able to recover after infection, while cells infected with normal virus died within 3 days. The P726S mutation did not reduce the susceptibility of 5- and 14-day-old mice to 633 and TE viruses in vivo. In addition, animal survival with the P726S variant viruses was increased and GFP expression was sustained for at least 14 days while the 633 and TE infection resulted in short-term GFP expression or an earlier mortality. Modifications to the host BHK and CHO cells themselves were subsequently undertaken by including the anti-apoptotic gene Bcl-2 and a deletion mutant of Bcl-2 (Bcl-2Delta) as another method for limiting the cytopathic effects of the Sindbis virus. The inclusion of anti-apoptotic genes permitted higher production of heterologous GFP protein following Sindbis virus infection, and the combination of the TE-P726S virus and the CHO-Bcl-2Delta cell line showed the greatest improvement in cell survival. Sindbis virus infection also induced ER stress in mammalian cells as detected by increased PERK phosphorylation and ATF4 translation. Overexpression of Parkin, an E3 ubiquitin ligase that can protect cells against agents that induce ER stress, suppressed Sindbis virus-induced cell death in both BHK cells and in vivo studies in mice. Such findings show that viral and host modifications can improve cell survival and production of heterologous proteins, change viral behavior in vitro and in vivo, and assist in the development of new expression or gene delivery vehicles.
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Affiliation(s)
- Toey Nivitchanyong
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, United States.
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The application of SELDI-TOF mass spectrometry to mammalian cell culture. Biotechnol Adv 2008; 27:177-84. [PMID: 19049820 DOI: 10.1016/j.biotechadv.2008.10.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2008] [Revised: 10/28/2008] [Accepted: 10/30/2008] [Indexed: 11/20/2022]
Abstract
Surface Enhanced Laser Desorption/Ionisation Time-of-Fight Mass Spectrometry (SELDI-TOF MS) is a technique by which protein profiles can be rapidly produced from a wide variety of biological samples. By employing chromatographic surfaces combined with the specificity and reproducibility of mass spectrometry it has allowed for profiles from complex biological samples to be analysed. Profiling and biomarker identification have been employed widely throughout the biological sciences. To date, however, the benefits of SELDI-TOF MS have not been realised in the area of mammalian cell culture. The advantages in identifying markers for cell stresses, apoptosis and other culture parameters mean that these tools could help greatly to enhance monitoring and control of bioreaction process and improve the production of therapeutics. Better characterisation of culture systems through proteome analysis will allow for improved productivity and better yields.
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Majors BS, Betenbaugh MJ, Pederson NE, Chiang GG. Enhancement of transient gene expression and culture viability using Chinese hamster ovary cells overexpressing Bcl-x(L). Biotechnol Bioeng 2008; 101:567-78. [PMID: 18727128 DOI: 10.1002/bit.21917] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Transient gene expression (TGE) provides a method for quickly delivering protein for research using mammalian cells. While high levels of recombinant proteins have been produced in TGE experiments in HEK 293 cells, TGE efforts in the commercially prominent CHO cell line still suffer from inadequate protein yields. Here, we describe a cell-engineering strategy to improve transient production of proteins using CHO cells. CHO-DG44 cells were engineered to overexpress the anti-apoptotic protein Bcl-x(L) and transiently transfected using polyethylenimine (PEI) in serum-free media. Pools and cell lines stably expressing Bcl-x(L) showed enhanced viable cell density and increased production of a glycosylated, therapeutic fusion protein in shake flask TGE studies. The improved cell lines showed fusion protein production levels ranging from 12.6 to 27.0 mg/L in the supernatant compared to the control cultures which produced 6.3-7.3 mg/L, representing a 70-270% increase in yield after 14 days of fed-batch culture. All Bcl-xL-expressing cell lines also exhibited an increase in specific productivity during the first 8 days of culture. In addition to increased production, Bcl-x(L) cell lines maintained viabilities above 90% and less apoptosis compared to the DG44 host which had viabilities below 60% after 14 days. Product quality was comparable between a Bcl-xL-engineered cell line and the CHO host. The work presented here provides the foundation for using anti-apoptosis engineered CHO cell lines for increased production of therapeutic proteins in TGE applications.
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Affiliation(s)
- Brian S Majors
- Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, 3400 North Charles Street, 221 Maryland Hall, Baltimore, Maryland 21218-2694, USA
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25
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E2F-1 overexpression increases viable cell density in batch cultures of Chinese hamster ovary cells. J Biotechnol 2008; 138:103-6. [DOI: 10.1016/j.jbiotec.2008.08.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2008] [Revised: 08/04/2008] [Accepted: 08/11/2008] [Indexed: 12/17/2022]
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Nivitchanyong T, Martinez A, Ishaque A, Murphy JE, Konstantinov K, Betenbaugh MJ, Thrift J. Anti-apoptotic genes Aven and E1B-19K enhance performance of BHK cells engineered to express recombinant factor VIII in batch and low perfusion cell culture. Biotechnol Bioeng 2007; 98:825-41. [PMID: 17514750 DOI: 10.1002/bit.21479] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The engineering of production cell lines to express anti-apoptotic genes has been pursued in recent years due to potential process benefits, including enhanced cell survival, increased protein expression, and improved product quality. In this study, a baby hamster kidney cell line secreting recombinant factor VIII (BHK-FVIII) was engineered to express the anti-apoptotic genes Aven and E1B-19K. In high cell density shake flask culture evaluation, 11 clonal cell lines expressing either E1B-19K or a combination of Aven and E1B-19K showed improved survival compared to both parental and blank vector cell line controls. These cell lines exhibited lower caspase-3 activation and reduced Annexin-V binding compared to the controls. Parental and blank vector cell lines were less than 50% viable after 48 h of exposure to thapsigargin while cell lines expressing E1B-19K with or without Aven maintained viabilities approaching 90%. Subsequently, the best Aven-E1B-19K candidate cell line was compared to the parental cell line in 12-L perfusion bioreactor studies. Choosing the appropriate perfusion rates in bioreactors is a bioprocess optimization issue, so the bioreactors were operated at sequentially lower specific perfusion rates, while maintaining a cell density of 2 x 10(7) viable cells/mL. The viability of the parental cell line declined from nearly 100% at a perfusion rate of 0.5 nL/cell/day to below 80% viability, with caspase-3 activity exceeding 15%, at its lower perfusion limit of 0.15 nL/cell/day. In contrast, the Aven-E1B-19K cell line maintained an average viability of 94% and a maximum caspase-3 activity of 2.5% even when subjected to a lower perfusion minimum of 0.1 nL/cell/day. Factor VIII productivity, specific growth rate, and cell size decreased for both cell lines at lower perfusion rates, but the drop in all cases was larger for the parental cell line. Specific consumption of glucose and glutamine and production of lactate were consistently lower for the Aven-E1B-19K culture. Furthermore, the yield of ammonia from glutamine increased for the Aven-E1B-19K cell line relative to the parent to suggest altered metabolic pathways following anti-apoptosis engineering. These results demonstrate that expression of anti-apoptotic genes Aven and E1B-19K can increase the stability and robustness of an industrially relevant BHK-FVIII mammalian cell line over a wide range of perfusion rates.
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Affiliation(s)
- Toey Nivitchanyong
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, USA
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27
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Griffin TJ, Seth G, Xie H, Bandhakavi S, Hu WS. Advancing mammalian cell culture engineering using genome-scale technologies. Trends Biotechnol 2007; 25:401-8. [PMID: 17681628 DOI: 10.1016/j.tibtech.2007.07.004] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2007] [Revised: 05/21/2007] [Accepted: 07/18/2007] [Indexed: 11/23/2022]
Abstract
Mammalian cell-derived protein therapeutic production has changed the landscape of human healthcare in the past two decades. The importance of protein therapeutics has motivated the search for more cost-effective and efficient cell lines capable of producing high quality protein products. The factors contributing to optimal producer cell lines are often complex, and not simply conferred by one gene or gene product, which makes an understanding of system-wide properties for better engineering of optimized cell lines essential. Genome-scale technologies (genomics, transcriptomics and proteomics) enable such engineering studies. However, the use of these technologies in cell culture engineering is still in its infancy. Here, we summarize current knowledge of cell properties important for the design of efficient protein-producing mammalian cell lines, and highlight relevant studies to-date that use genome-scale technologies in these cell systems. We also provide a focused review of relevant alternative and emerging technologies, which have seen limited use in cell culture engineering, but hold great potential for significant advancements in protein therapeutic production.
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Affiliation(s)
- Timothy J Griffin
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA.
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28
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Majors BS, Betenbaugh MJ, Chiang GG. Links between metabolism and apoptosis in mammalian cells: applications for anti-apoptosis engineering. Metab Eng 2007; 9:317-26. [PMID: 17611135 DOI: 10.1016/j.ymben.2007.05.003] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2007] [Revised: 05/16/2007] [Accepted: 05/16/2007] [Indexed: 10/23/2022]
Abstract
Production of complex recombinant proteins requires the culture of mammalian cells in bioreactors. Inherent in these cultures is the problem of cell death, which can result from nutrient depletion, byproduct accumulation, and other bioreactor stresses which signal the cell to die through apoptosis, or programmed cell death. Apoptosis is a highly regulated pathway of both pro- and anti-apoptotic proteins that promote cell survival or death, and cell engineering efforts to inhibit the apoptosis pathway have led to increased culture viability and recombinant protein production. Originally, the exclusive function of many of these pathway proteins was believed to be binding at the mitochondria and regulating apoptosis through modulation of the mitochondria permeability. While this protein functionality does still hold true, it is now evident that these proteins also include roles in the metabolic processes of the mitochondria. Furthermore, apoptosis pathway proteins in other organelles within the cell may also both modulate apoptosis and metabolism. This review first details the known links that exist between apoptosis proteins and metabolic functions in the cytosol, mitochondria, and endoplasmic reticulum. Second, the review turns to look at potentially new cell engineering strategies that are linked to metabolism for improving cell culture viability and protein production.
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Affiliation(s)
- Brian S Majors
- Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, 3400 North Charles Street, 221 Maryland Hall, Baltimore, MD 21218-2694, USA
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29
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Cittelly DM, Nesic O, Johnson K, Hulsebosch C, Perez-Polo JR. Detrimental effects of antiapoptotic treatments in spinal cord injury. Exp Neurol 2007; 210:295-307. [PMID: 18302959 DOI: 10.1016/j.expneurol.2007.03.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2006] [Revised: 02/27/2007] [Accepted: 03/01/2007] [Indexed: 10/23/2022]
Abstract
Long-term functional impairments due to spinal cord injury (SCI) in the rat result from secondary apoptotic death regulated, in part, by SCI-induced decreases in protein levels of the antiapoptotic protein Bcl-xL. We have shown that exogenous administration of Bcl-xL spares neurons 24 h after SCI. However, long-term effects of chronic application of Bcl-xL have not been characterized. To counteract SCI-induced decreases in Bcl-xL and resulting apoptosis, we used the TAT protein transduction domain fused to the Bcl-xL protein (Tat-Bcl-xL), or its antiapoptotic domain BH4 (Tat-BH4). We used intrathecal delivery of Tat-Bcl-xL, or Tat-BH4, into injured spinal cords for 24 h or 7 days, and apoptosis, neuronal death and locomotor recovery were assessed up to 2 months after injury. Both, Tat-Bcl-xL and Tat-BH4, significantly decreased SCI-induced apoptosis in thoracic segments containing the site of injury (T10) at 24 h or 7 days after SCI. However, the 7-day delivery of Tat-Bcl-xL, or Tat-BH4, also induced a significant impairment of locomotor recovery that lasted beyond the drug delivery time. We found that the 7-day administration of Tat-Bcl-xL, or Tat-BH4, significantly increased non-apoptotic neuronal loss and robustly augmented microglia/macrophage activation. These results indicate that the antiapoptotic treatment targeting Bcl-xL shifts neuronal apoptosis to necrosis, increases the inflammatory response and impairs locomotor recovery. Our results suggest that a combinatorial treatment consisting of antiapoptotic and anti-inflammatory agents may be necessary to achieve tissue preservation and significant improvement in functional recovery after SCI.
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Affiliation(s)
- Diana M Cittelly
- Neurosciences and Cell Biology, University of Texas Medical Branch, Galveston, Texas 77555, USA
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Arden N, Majors BS, Ahn SH, Oyler G, Betenbaugh MJ. Inhibiting the apoptosis pathway using MDM2 in mammalian cell cultures. Biotechnol Bioeng 2007; 97:601-14. [PMID: 17149774 DOI: 10.1002/bit.21254] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The ability to regulate apoptosis in mammalian cell cultures represents one approach to developing more economical and efficient processes. Genetic modification of cells using anti-apoptotic genes is one method that may be used to improve cellular performance. This study investigates a method to inhibit upstream apoptosis pathways through the overexpression of MDM2, an E3 ubiquitin ligase for p53. Both 293 and CHO cells expressing MDM2 were examined under both batch and spent media conditions. For batch cultures, MDM2 overexpression increased viable cell densities and viabilities over control cells with the largest enhancements observed in CHO cells. When CHO cells were passaged without medium exchange, cells expressing MDM2 reached a viable cell density that was nearly double the control and survived for an extra day in culture. When exposed to spent media initially, both 293-MDM2 and CHO-MDM2 cells continued to grow for 2 days while the control cells stopped growing after the first day. DNA analysis using flow cytometry confirmed that while CHO controls were found to be undergoing DNA fragmentation, CHO-MDM2 cells exhibit DNA degradation at a much slower rate. When compared to Bcl-2-expressing cells, MDM2 expression showed greater protection against apoptosis in passaged culture, spent medium, and following transient p53 overexpression. However, expression of the RING sequence of MDM2 responsible for E3 ligase activity without the other components of the protein was found to be toxic to 293 cells in culture. These results suggest that the overexpression of heterologous MDM2 represents a promising method to delay apoptosis in mammalian cell cultures.
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Affiliation(s)
- Nilou Arden
- Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, USA
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Liu X, Zhu Y, Dai S, White J, Peyerl F, Kappler JW, Marrack P. Bcl-xl does not have to bind Bax to protect T cells from death. J Exp Med 2006; 203:2953-61. [PMID: 17158961 PMCID: PMC2118172 DOI: 10.1084/jem.20061151] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2006] [Accepted: 11/26/2006] [Indexed: 11/09/2022] Open
Abstract
Activated T cells die when antigen disappears from animals. This death is caused by proteins related to Bcl-2. Two hypotheses have been suggested to explain the actions of the different types of Bcl-2 proteins. One hypothesis suggests that, when T cells prepare to die, Bak and Bax, the proteins that actually kill activated T cells, are released from antiapoptotic proteins such as Bcl-2 and Bcl-xl. Another hypothesis suggests that Bak and Bax are normally free and are triggered to kill cells by release of messenger proteins, such as Bim, from Bcl-2 and Bcl-xl. Here, a form of Bcl-xl, which lacks a long unstructured loop, is used to show that the first hypothesis is not correct. Bcl-xl without its loop protects activated T cells from death, yet Bcl-xl without its loop cannot bind any form of Bak and Bax. Thus, binding of Bcl-xl to Bak or Bax is not involved in T cell life or death. The loop of Bcl-xl is also somewhat involved in Bcl-xl's binding of Bim because Bcl-xl without its loop binds Bim less well than wild-type Bcl-xl. Moreover, the loop may have additional, as yet unknown, functions because it changes its shape when Bcl-xl binds Bim.
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Affiliation(s)
- Xinqi Liu
- Howard Hughes Medical Institute and Integrated Department of Immunology, National Jewish Medical and Research Center, Denver, CO 80206, USA
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O'Connor KC, Muhitch JW, Lacks DJ, Al-Rubeai M. Modeling suppression of cell death by Bcl-2 over-expression in myeloma NS0 6A1 cells. Biotechnol Lett 2006; 28:1919-24. [PMID: 16988783 DOI: 10.1007/s10529-006-9177-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2006] [Accepted: 07/26/2006] [Indexed: 10/24/2022]
Abstract
A novel population-balance model was employed to evaluate the suppression of cell death in myeloma NS0 6A1 cells metabolically engineered to over-express the apoptotic suppressor Bcl-2. The model is robust in its ability to simulate cell population dynamics in batch suspension culture and in response to thymidine-induced growth inhibition: 89% of simulated cell concentrations are within two standard deviations of experimental data. Kinetic rate constants in model equations suggest that Bcl-2 over-expression extends culture longevity from 6 days to at least 15 days by suppressing the specific rate of early apoptotic cell formation by more than 6-fold and necrotic cell formation by at least 3-fold, despite nearly a 3-fold decrease in initial cell growth rate and no significant change in the specific rate of late apoptotic cell formation. This computational analysis supports a mechanism in which Bcl-2 is a common mediator of early apoptotic and necrotic events occurring at rates that are dependent on cellular factors accumulating over time. The model has current application to the rational design of cell cultures through metabolic engineering for the industrial production of biopharmaceuticals.
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Affiliation(s)
- Kim C O'Connor
- Department of Chemical and Biomolecular Engineering, Tulane University, New Orleans, LA 70118, USA
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Arden N, Betenbaugh MJ. Regulating apoptosis in mammalian cell cultures. Cytotechnology 2006; 50:77-92. [PMID: 19003072 DOI: 10.1007/s10616-006-9008-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2006] [Accepted: 03/31/2006] [Indexed: 12/19/2022] Open
Abstract
Cell culture technology has become a widely accepted method used to derive therapeutic and diagnostic protein products. Mammalian cells adapted to grow in bioreactors now play an integral role in the development of these biologicals. A major limiting factor determining the output efficiency of mammalian cell cultures however, is apoptosis or programmed cell death. Methods to delay apoptosis and increase the longevity of cell cultures can lead to more economical processes. Researchers have shown that both genetic and chemical strategies to block apoptotic signals can increase cell culture productivity. Here, we discuss various strategies which have been implemented to improve cellular viabilities and productivities in batch cultures.
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Affiliation(s)
- Nilou Arden
- Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD, 21218, USA
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34
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Shi M, Xie Z, Yu M, Shen B, Guo N. Controlled growth of Chinese hamster ovary cells and high expression of antibody-IL-2 fusion proteins by temperature manipulation. Biotechnol Lett 2006; 27:1879-84. [PMID: 16328984 DOI: 10.1007/s10529-005-3897-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2005] [Revised: 08/17/2005] [Accepted: 09/27/2005] [Indexed: 10/25/2022]
Abstract
Growth and the expression of the anti-ErbB2 scFv-Fc-IL2 fusion protein in Chinese hamster ovary (CHO) cells were in association at 37 degrees C. The expression of the fusion protein was no more than 25 microg/ml. At 30 degrees C the cell growth was arrested but the cells continued to produce the fusion protein up to 60-80 microg/ml. About 50% of CHO cells were rapidly blocked in G2/M phase after the temperature was shifted from 37 to 30 degrees C. Lowering temperature resulted in cell growth arrest, but maintained cell viability for a longer time and enhanced the production of the antibody-IL-2 fusion protein in CHO cells.
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Affiliation(s)
- Ming Shi
- Department of Molecular Immunology, Institute of Basic Medical Sciences, 27 Taiping Road, 100850 Beijing, P.R. China
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35
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Peterson NC, Servinsky M. Characterization of the effects of Bcl-2 and Bcl-xl deletion mutant expression in cell lines used for antibody production. Hybridoma (Larchmt) 2006; 24:275-82. [PMID: 16332193 DOI: 10.1089/hyb.2005.24.275] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Strategies to maximize monoclonal antibody (MAb) yields by in vitro production methods entail that hybridoma cells be maintained at high density. Approaches to increase culture density and antibody yields from hybridomas by inhibiting apoptosis through over-expression of exogenous Bcl-2 family genes have produced variable results. In order to determine if expression of mutant forms of Bcl-2 and Bcl-xl could increase viable culture densities and batch MAb yields when compared to parental cell lines, recombinant delta loop deletion mutant of these apoptotic inhibitory genes were expressed in a myeloma and two hybridoma cell lines. Expression of either Bcl-2-delta or Bcl-xl-delta in P3x63Ag8.653 myeloma cells did not significantly increase viable cell densities in cultures over time. However, the rapid post-peak decline in viable cell density was significantly reduced in Bcl-xl-delta-expressing hybridoma cell lines 552 and 7.16.4 and in Bcl-2-expressing hybridoma 7.16.4. Significant increases in MAb yield were only observed in cultures of Bcl-xl-delta-expressing hybridoma 7.16.4. Annexin staining in hybridoma 7.16.4 confirmed that apoptosis was the primary means of cell death in this cell line, and expression of Bcl-2-delta and Bcl-xl-delta inhibited programmed cell death. These results suggest that cell viability in cultures can be improved by transfection and selection of hybridomas that express delta loop deletion mutant forms of Bcl-2 family genes; however, improvements in MAb yields are dependent upon the genetic background of each manipulated cell line.
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Affiliation(s)
- Norman C Peterson
- Department of Comparative Medicine, Johns Hopkins University, Baltimore, Maryland, USA.
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Seth G, Hossler P, Yee JC, Hu WS. Engineering cells for cell culture bioprocessing--physiological fundamentals. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2006; 101:119-64. [PMID: 16989260 DOI: 10.1007/10_017] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In the past decade, we have witnessed a tremendous increase in the number of mammalian cell-derived therapeutic proteins with clinical applications. The success of making these life-saving biologics available to the public is partly due to engineering efforts to enhance process efficiency. To further improve productivity, much effort has been devoted to developing metabolically engineered producing cells, which possess characteristics favorable for large-scale bioprocessing. In this article we discuss the fundamental physiological basis for cell engineering. Different facets of cellular mechanisms, including metabolism, protein processing, and the balancing pathways of cell growth and apoptosis, contribute to the complex traits of favorable growth and production characteristics. We present our assessment of the current state of the art by surveying efforts that have already been undertaken in engineering cells for a more robust process. The concept of physiological homeostasis as a key determinant and its implications on cell engineering is emphasized. Integrating the physiological perspective with cell culture engineering will facilitate attainment of dream cells with superlative characteristics.
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Affiliation(s)
- Gargi Seth
- Department of Chemical Engineering and Materials Science, University of Minnesota, 421 Washington Avenue SE, Minneapolis, MN 55455-0132, USA
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Chiang GG, Sisk WP. Bcl-x(L) mediates increased production of humanized monoclonal antibodies in Chinese hamster ovary cells. Biotechnol Bioeng 2005; 91:779-92. [PMID: 15986489 DOI: 10.1002/bit.20551] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Enhanced product yields, reduction in throughput time, improved cost-effectiveness and product quality are examples of benefits gained by delaying apoptotic cell death in bioreactors. To examine the effect on recombinant protein production, bcl-x(L) was overexpressed in a CHO cell line secreting humanized monoclonal antibody directed against the alpha1beta1 integrin. When cell lines overexpressing bcl-x(L) were compared to the parent, cell viability was increased by 20% and titers by 80%. Total viable cell densities were similar and specific productivities were enhanced by almost two-fold on scale-up to bioreactors. Comparison in a chemically defined media demonstrated an even greater sustained viability in bcl-x(L) expressing cells by 50% and up to 90% increase in titer with no impact on product quality. Caspase 3 activities were monitored as a marker for apoptotic cell death. In the presence of Bcl-x(L), caspase activities were reduced to background levels. The role of Bcl-x(L) in protecting cells from premature death was further examined in studies performed in the presence of NaBu, at concentrations known to trigger cell death. Results demonstrated that cells expressing bcl-x(L) retained 88% cell viability with >2 fold increase in titer. Bcl-x(L) was similarly overexpressed in a different CHO cell line producing a humanized mAb against the chemokine MCP1. Once again, production titer was increased by 80% and viability by 75%. Together the studies have shown that overexpression of bcl-x(L) in production cell lines was able to significantly increase the titer by enhancing both the specific activity and total cell viability while maintaining product quality.
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Affiliation(s)
- Gisela G Chiang
- Cellular Engineering Technology Group, Biogen Idec, Inc., 14 Cambridge Center, Cambridge, Massachusetts 02142, USA.
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Figueroa B, Chen S, Oyler GA, Hardwick JM, Betenbaugh MJ. Aven and Bcl-xL enhance protection against apoptosis for mammalian cells exposed to various culture conditions. Biotechnol Bioeng 2004; 85:589-600. [PMID: 14966800 DOI: 10.1002/bit.10913] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
A balance between proliferation and cell death is critical for achieving desirable high cell densities in mammalian cell culture. In this study, we evaluate a recently discovered anti-apoptotic gene, aven, and examine its effectiveness alone and in combination with a member of the Bcl-2 family, bcl-xL. The commercially popular cell line, Chinese hamster ovary (CHO), was genetically modified to constitutively express aven, bcl-xL, and the two genes in combination. Cells were exposed to several model insults that simulate severe bioreactor environments, including serum deprivation, spent medium, and Sindbis virus infection, as well as staurosporine, a known chemical inducer of apoptosis. CHO cells exhibited DNA fragmentation, a hallmark of apoptosis, after exposure to these model insults. After exposure to serum deprivation, 4- and 5-day spent medium, and staurosporine, cells expressing Aven provided limited protection against cell death when compared with the protection afforded by cells expressing Bcl-xL alone. However, the highest survival levels for all insults were achieved when Aven was expressed in combination with Bcl-xL. In fact, Aven appeared to act synergistically to enhance the protective function of Bcl-xL for several insults, because the protective function of the two genes expressed together in one cell line often exceeded the additive protective levels of each anti-apoptosis gene expressed alone. Surprisingly, Aven expression provided a mildly pro-apoptotic response in CHO isolates infected with Sindbis virus. However, CHO cells expressing both Bcl-xL and Aven showed protection against Sindbis virus infection due to the inhibitory properties of the bcl-xL anti-apoptosis gene. This study shows that combinatorial anti-apoptosis cell engineering strategies may be the most effective mechanisms for providing extended protection against cell death in mammalian cell culture.
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Affiliation(s)
- Bruno Figueroa
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, USA
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Arden N, Betenbaugh MJ. Life and death in mammalian cell culture: strategies for apoptosis inhibition. Trends Biotechnol 2004; 22:174-80. [PMID: 15038922 DOI: 10.1016/j.tibtech.2004.02.004] [Citation(s) in RCA: 179] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Mammalian cell culture is widely used to produce valuable biotherapeutics including monoclonal antibodies, vaccines and growth factors. Industrial cell lines such as Chinese hamster ovary (CHO), mouse myeloma (NS0), baby hamster kidney (BHK) and human embryonic kidney (HEK)-293 retain many molecular components of the apoptosis cascade. Consequently, these cells often undergo programmed cell death upon exposure to stresses encountered in bioreactors. The implementation of strategies to control apoptosis and enhance culture productivities represents a major goal of biotechnologists. Fortunately, previous research has uncovered many intracellular proteins involved in activating and inhibiting apoptosis. Here, we summarize three apoptotic pathways and discuss different environmental and genetic methodologies implemented to limit cell death for biotechnology applications.
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Affiliation(s)
- Nilou Arden
- Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA
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