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Malm M, Kuo CC, Barzadd MM, Mebrahtu A, Wistbacka N, Razavi R, Volk AL, Lundqvist M, Kotol D, Tegel H, Hober S, Edfors F, Gräslund T, Chotteau V, Field R, Varley PG, Roth RG, Lewis NE, Hatton D, Rockberg J. Harnessing secretory pathway differences between HEK293 and CHO to rescue production of difficult to express proteins. Metab Eng 2022; 72:171-187. [PMID: 35301123 PMCID: PMC9189052 DOI: 10.1016/j.ymben.2022.03.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 02/09/2022] [Accepted: 03/10/2022] [Indexed: 10/31/2022]
Abstract
Biologics represent the fastest growing group of therapeutics, but many advanced recombinant protein moieties remain difficult to produce. Here, we identify metabolic engineering targets limiting expression of recombinant human proteins through a systems biology analysis of the transcriptomes of CHO and HEK293 during recombinant expression. In an expression comparison of 24 difficult to express proteins, one third of the challenging human proteins displayed improved secretion upon host cell swapping from CHO to HEK293. Guided by a comprehensive transcriptomics comparison between cell lines, especially highlighting differences in secretory pathway utilization, a co-expression screening of 21 secretory pathway components validated ATF4, SRP9, JUN, PDIA3 and HSPA8 as productivity boosters in CHO. Moreover, more heavily glycosylated products benefitted more from the elevated activities of the N- and O-glycosyltransferases found in HEK293. Collectively, our results demonstrate the utilization of HEK293 for expression rescue of human proteins and suggest a methodology for identification of secretory pathway components for metabolic engineering of HEK293 and CHO.
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Affiliation(s)
- Magdalena Malm
- Dept. of Protein Science, KTH - Royal Institute of Technology, Stockholm, SE-106 91, Sweden
| | - Chih-Chung Kuo
- Departments of Pediatrics and Bioengineering, University of California, San Diego, La Jolla, CA, 92093, USA; The Novo Nordisk Foundation Center for Biosustainability at the University of California, San Diego, CA, 92093, USA
| | - Mona Moradi Barzadd
- Dept. of Protein Science, KTH - Royal Institute of Technology, Stockholm, SE-106 91, Sweden
| | - Aman Mebrahtu
- Dept. of Protein Science, KTH - Royal Institute of Technology, Stockholm, SE-106 91, Sweden
| | - Num Wistbacka
- Dept. of Protein Science, KTH - Royal Institute of Technology, Stockholm, SE-106 91, Sweden
| | - Ronia Razavi
- Dept. of Protein Science, KTH - Royal Institute of Technology, Stockholm, SE-106 91, Sweden
| | - Anna-Luisa Volk
- Dept. of Protein Science, KTH - Royal Institute of Technology, Stockholm, SE-106 91, Sweden
| | - Magnus Lundqvist
- Dept. of Protein Science, KTH - Royal Institute of Technology, Stockholm, SE-106 91, Sweden
| | - David Kotol
- Science for Life Laboratory, KTH - Royal Institute of Technology, Solna, 171 65, Sweden
| | - Hanna Tegel
- Dept. of Protein Science, KTH - Royal Institute of Technology, Stockholm, SE-106 91, Sweden
| | - Sophia Hober
- Dept. of Protein Science, KTH - Royal Institute of Technology, Stockholm, SE-106 91, Sweden
| | - Fredrik Edfors
- Science for Life Laboratory, KTH - Royal Institute of Technology, Solna, 171 65, Sweden
| | - Torbjörn Gräslund
- Dept. of Protein Science, KTH - Royal Institute of Technology, Stockholm, SE-106 91, Sweden
| | - Veronique Chotteau
- Dept. of Industrial Biotechnology, KTH - Royal Institute of Technology, Stockholm, SE-10691, Sweden
| | - Ray Field
- Cell Culture and Fermentation Sciences, BioPharmaceutical Development, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Paul G Varley
- Cell Culture and Fermentation Sciences, BioPharmaceutical Development, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Robert G Roth
- Discovery Biology, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Nathan E Lewis
- Departments of Pediatrics and Bioengineering, University of California, San Diego, La Jolla, CA, 92093, USA; The Novo Nordisk Foundation Center for Biosustainability at the University of California, San Diego, CA, 92093, USA.
| | - Diane Hatton
- Cell Culture and Fermentation Sciences, BioPharmaceutical Development, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Johan Rockberg
- Dept. of Protein Science, KTH - Royal Institute of Technology, Stockholm, SE-106 91, Sweden.
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2
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DNA Transfer into Animal Cells Using Stearylated CPP Based Transfection Reagent. Methods Mol Biol 2021; 2383:569-578. [PMID: 34766314 DOI: 10.1007/978-1-0716-1752-6_36] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/06/2023]
Abstract
Mammalian transient expression systems enable flexible and rapid production of proteins. They're ideal for expression of human or other mammalian proteins because these systems generate recombinant proteins with more native folding and post-translational modifications-such as glycosylation-than expression systems based on hosts such as E. coli, yeast, or insect cells.Here we describe transient protein production using QMCF Technology (Icosagen, Estonia) that uses specific suspension-adapted mammalian cell lines (QMCF cells), appropriate QMCF episomal expression vector, a chemically defined animal origin-free, serum-free medium, and Reagent 007™ (Icosagen, Estonia) for efficient delivery of nucleic acids for transfection of mammalian cells in comparison with PEI MAX™ (Transfection Grade Linear Polyethylenimine Hydrochloride, Polysciences).
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3
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Eesmaa A, Yu LY, Göös H, Nõges K, Kovaleva V, Hellman M, Zimmermann R, Jung M, Permi P, Varjosalo M, Lindholm P, Saarma M. The cytoprotective protein MANF promotes neuronal survival independently from its role as a GRP78 cofactor. J Biol Chem 2021; 296:100295. [PMID: 33460650 PMCID: PMC7949057 DOI: 10.1016/j.jbc.2021.100295] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 01/07/2021] [Accepted: 01/12/2021] [Indexed: 12/14/2022] Open
Abstract
Mesencephalic astrocyte-derived neurotrophic factor (MANF) is an endoplasmic reticulum (ER)-stress-regulated protein exhibiting cytoprotective properties through a poorly understood mechanism in various in vitro and in vivo models of neuronal and non-neuronal damage. Although initially characterized as a secreted neurotrophic factor for midbrain dopamine neurons, MANF has recently gained more interest for its intracellular role in regulating the ER homeostasis, including serving as a cofactor of the chaperone glucose-regulated protein 78 (GRP78). We aimed for a better understanding of the neuroprotective mechanisms of MANF. Here we show for the first time that MANF promotes the survival of ER-stressed neurons in vitro as a general unfolded protein response (UPR) regulator, affecting several UPR pathways simultaneously. Interestingly, MANF does not affect naïve neurons. We hypothesize that MANF regulates UPR signaling toward a mode more compatible with neuronal survival. Screening of MANF interacting proteins from two mammalian cell lines revealed a conserved interactome of 15 proteins including several ER chaperones such as GRP78, GRP170, protein disulfide isomerase family A member 1, and protein disulfide isomerase family A member 6. Further characterization confirmed previously published finding that MANF is a cofactor of GRP78 interacting with its nucleotide binding domain. Using microscale thermophoresis and nuclear magnetic resonance spectroscopy, we discovered that MANF is an ATP binding protein and that ATP blocks the MANF-GRP78 interaction. Interestingly, functional analysis of the antiapoptotic properties of MANF mutants in cultured neurons revealed divergent roles of MANF as a GRP78 cofactor and as an antiapoptotic regulator of UPR. We conclude that the co-factor type interaction with GRP78 is dispensable for the survival-promoting activity of MANF in neurons.
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Affiliation(s)
- Ave Eesmaa
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Li-Ying Yu
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Helka Göös
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Kristofer Nõges
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Vera Kovaleva
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Maarit Hellman
- Department of Chemistry, Nanoscience Center, University of Jyväskylä, Jyväskylä, Finland
| | - Richard Zimmermann
- Medical Biochemistry and Molecular Biology, Saarland University, Homburg, Germany
| | - Martin Jung
- Medical Biochemistry and Molecular Biology, Saarland University, Homburg, Germany
| | - Perttu Permi
- Department of Chemistry, Nanoscience Center, University of Jyväskylä, Jyväskylä, Finland; Department of Biological and Environmental Science, Nanoscience Center, University of Jyväskylä, Jyväskylä, Finland
| | - Markku Varjosalo
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Päivi Lindholm
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland.
| | - Mart Saarma
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland.
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4
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Tegel H, Dannemeyer M, Kanje S, Sivertsson Å, Berling A, Svensson AS, Hober A, Enstedt H, Volk AL, Lundqvist M, Moradi M, Afshari D, Ekblad S, Xu L, Westin M, Bidad F, Schiavone LH, Davies R, Mayr LM, Knight S, Göpel SO, Voldborg BG, Edfors F, Forsström B, von Feilitzen K, Zwahlen M, Rockberg J, Takanen JO, Uhlén M, Hober S. High throughput generation of a resource of the human secretome in mammalian cells. N Biotechnol 2020; 58:45-54. [DOI: 10.1016/j.nbt.2020.05.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 05/04/2020] [Accepted: 05/30/2020] [Indexed: 02/07/2023]
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5
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Ding M, Tegel H, Sivertsson Å, Hober S, Snijder A, Ormö M, Strömstedt PE, Davies R, Holmberg Schiavone L. Secretome-Based Screening in Target Discovery. SLAS DISCOVERY : ADVANCING LIFE SCIENCES R & D 2020; 25:535-551. [PMID: 32425085 PMCID: PMC7309359 DOI: 10.1177/2472555220917113] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 03/02/2020] [Accepted: 03/10/2020] [Indexed: 12/15/2022]
Abstract
Secreted proteins and their cognate plasma membrane receptors regulate human physiology by transducing signals from the extracellular environment into cells resulting in different cellular phenotypes. Systematic use of secretome proteins in assays enables discovery of novel biology and signaling pathways. Several secretome-based phenotypic screening platforms have been described in the literature and shown to facilitate target identification in drug discovery. In this review, we summarize the current status of secretome-based screening. This includes annotation, production, quality control, and sample management of secretome libraries, as well as how secretome libraries have been applied to discover novel target biology using different disease-relevant cell-based assays. A workflow for secretome-based screening is shared based on the AstraZeneca experience. The secretome library offers several advantages compared with other libraries used for target discovery: (1) screening using a secretome library directly identifies the active protein and, in many cases, its cognate receptor, enabling a rapid understanding of the disease pathway and subsequent formation of target hypotheses for drug discovery; (2) the secretome library covers significant areas of biological signaling space, although the size of this library is small; (3) secretome proteins can be added directly to cells without additional manipulation. These factors make the secretome library ideal for testing in physiologically relevant cell types, and therefore it represents an attractive approach to phenotypic target discovery.
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Affiliation(s)
- Mei Ding
- Discovery Biology, Discovery Sciences, R&D, AstraZeneca, Gothenburg, Sweden
| | - Hanna Tegel
- Department of Protein Science, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH, Royal Institute of Technology, Stockholm, Sweden
| | - Åsa Sivertsson
- Department of Protein Science, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH, Royal Institute of Technology, Stockholm, Sweden
| | - Sophia Hober
- Department of Protein Science, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH, Royal Institute of Technology, Stockholm, Sweden
| | - Arjan Snijder
- Discovery Biology, Discovery Sciences, R&D, AstraZeneca, Gothenburg, Sweden
| | - Mats Ormö
- Discovery Biology, Discovery Sciences, R&D, AstraZeneca, Gothenburg, Sweden
| | - Per-Erik Strömstedt
- Mechanistic Biology and Profiling, Discovery Sciences, R&D, AstraZeneca, Gothenburg, Sweden
| | - Rick Davies
- Discovery Biology, Discovery Sciences, R&D, AstraZeneca, Cambridge, UK
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6
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Lee JH, Park JH, Park SH, Kim SH, Kim JY, Min JK, Lee GM, Kim YG. Co-amplification of EBNA-1 and PyLT through dhfr-mediated gene amplification for improving foreign protein production in transient gene expression in CHO cells. Appl Microbiol Biotechnol 2018; 102:4729-4739. [PMID: 29654557 DOI: 10.1007/s00253-018-8977-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 03/23/2018] [Accepted: 03/28/2018] [Indexed: 12/30/2022]
Abstract
Despite the relatively low transfection efficiency and low specific foreign protein productivity (qp) of Chinese hamster ovary (CHO) cell-based transient gene expression (TGE) systems, TGE-based recombinant protein production technology predominantly employs CHO cells for pre-clinical research and development purposes. To improve TGE in CHO cells, Epstein-Barr virus nuclear antigen-1 (EBNA-1)/polyoma virus large T antigen (PyLT)-co-amplified recombinant CHO (rCHO) cells stably expressing EBNA-1 and PyLT were established using dihydrofolate reductase/methotrexate-mediated gene amplification. The level of transiently expressed Fc-fusion protein was significantly higher in the EBNA-1/PyLT-co-amplified pools compared to control cultures. Increased Fc-fusion protein production by EBNA-1/PyLT-co-amplification resulted from a higher qp attributable to EBNA-1 but not PyLT expression. The qp for TGE-based production with EBNA-1/PyLT-co-amplified rCHO cells (EP-amp-20) was approximately 22.9-fold that of the control culture with CHO-DG44 cells. Rather than improved transfection efficiency, this cell line demonstrated increased levels of mRNA expression and replicated DNA, contributing to an increased qp. Furthermore, there was no significant difference in N-glycan profiles in Fc-fusion proteins produced in the TGE system. Taken together, these results showed that the use of rCHO cells with co-amplified expression of the viral elements EBNA-1 and PyLT improves TGE-based therapeutic protein production dramatically. Therefore, EBNA-1/PyLT-co-amplified rCHO cells will likely be useful as host cells in CHO cell-based TGE systems.
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Affiliation(s)
- Joo-Hyoung Lee
- Department of Biological Sciences, KAIST, 335 Gwahak-ro, Yuseong-gu, Daejeon, South Korea.,Biotherapeutics Translational Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-gu, Daejeon, South Korea
| | - Jong-Ho Park
- Department of Biological Sciences, KAIST, 335 Gwahak-ro, Yuseong-gu, Daejeon, South Korea.,Biotherapeutics Translational Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-gu, Daejeon, South Korea
| | - Sun-Hye Park
- Biotherapeutics Translational Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-gu, Daejeon, South Korea.,Department of Bioprocess Engineering, KRIBB School of Biotechnology, Korea University of Science and Technology (UST), 217 Gajeong-ro, Yuseong-gu, Daejeon, South Korea
| | - Sun-Hong Kim
- Biotherapeutics Translational Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-gu, Daejeon, South Korea.,Department of Life Sciences, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
| | - Jee Yon Kim
- Department of Biological Sciences, KAIST, 335 Gwahak-ro, Yuseong-gu, Daejeon, South Korea
| | - Jeong-Ki Min
- Biotherapeutics Translational Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-gu, Daejeon, South Korea.,Department of Biomolecular Science, KRIBB School of Bioscience, Korea University of Science and Technology (UST), 217 Gajeong-ro, Yuseong-gu, Daejeon, South Korea
| | - Gyun Min Lee
- Department of Biological Sciences, KAIST, 335 Gwahak-ro, Yuseong-gu, Daejeon, South Korea.
| | - Yeon-Gu Kim
- Biotherapeutics Translational Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-gu, Daejeon, South Korea. .,Department of Bioprocess Engineering, KRIBB School of Biotechnology, Korea University of Science and Technology (UST), 217 Gajeong-ro, Yuseong-gu, Daejeon, South Korea.
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7
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Sankovski E, Abroi A, Ustav M, Ustav M. Nuclear myosin 1 associates with papillomavirus E2 regulatory protein and influences viral replication. Virology 2018; 514:142-155. [PMID: 29179037 DOI: 10.1016/j.virol.2017.11.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Revised: 11/09/2017] [Accepted: 11/16/2017] [Indexed: 11/25/2022]
Abstract
Nuclear myosin 1c (NM1) associates with RNA polymerases and is a partner in the chromatin remodeling complex B-WICH. This complex, which also contains WSTF and SNF2h proteins, is involved in transcriptional regulation. We report herein that papillomavirus protein E2 binds to NM1 and co-precipitates with the WSTF and SNF2h proteins. Our data suggest that E2 associates with the cellular B-WICH complex through binding to NM1. E2 and NM1 associate via their N-terminal domains and this interaction is ATP dependent. The cellular multifunctional protein Brd4 and beta-actin are also present in the NM1-E2 complex. NM1 downregulation by siRNA increases the replication of the BPV1 and HPV5 genomes but does not affect HPV18 genome replication. These results suggest that the B-WICH complex may play a role in the papillomavirus life cycle through NM1 and E2 protein interaction.
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Affiliation(s)
- Eve Sankovski
- University of Tartu, Institute of Technology, Nooruse 1, 50411 Tartu, Estonia
| | - Aare Abroi
- Estonian Biocentre, Riia 23, 51010 Tartu, Estonia
| | - Mart Ustav
- University of Tartu, Institute of Technology, Nooruse 1, 50411 Tartu, Estonia; Icosagen Cell Factory OÜ, Eerika tee 1, Õssu küla, Ülenurme vald, 61713 Tartumaa, Estonia
| | - Mart Ustav
- University of Tartu, Institute of Technology, Nooruse 1, 50411 Tartu, Estonia; Icosagen Cell Factory OÜ, Eerika tee 1, Õssu küla, Ülenurme vald, 61713 Tartumaa, Estonia; Estonian Academy of Sciences, Kohtu 6, 10130 Tallinn, Estonia.
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8
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Versatile microscale screening platform for improving recombinant protein productivity in Chinese hamster ovary cells. Sci Rep 2015; 5:18016. [PMID: 26657798 PMCID: PMC4676018 DOI: 10.1038/srep18016] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 11/10/2015] [Indexed: 11/09/2022] Open
Abstract
Chinese hamster ovary (CHO) cells are widely used as cell factories for the production of biopharmaceuticals. In contrast to the highly optimized production processes for monoclonal antibody (mAb)-based biopharmaceuticals, improving productivity of non-mAb therapeutic glycoproteins is more likely to reduce production costs significantly. The aim of this study was to establish a versatile target gene screening platform for improving productivity for primarily non-mAb glycoproteins with complete interchangeability of model proteins and target genes using transient expression. The platform consists of four techniques compatible with 96-well microplates: lipid-based transient transfection, cell cultivation in microplates, cell counting and antibody-independent product titer determination based on split-GFP complementation. We were able to demonstrate growth profiles and volumetric productivity of CHO cells in 96-half-deepwell microplates comparable with those obtained in shake flasks. In addition, we demonstrate that split-GFP complementation can be used to accurately measure relative titers of therapeutic glycoproteins. Using this platform, we were able to detect target gene-specific increase in titer and specific productivity of two non-mAb glycoproteins. In conclusion, the platform provides a novel miniaturized and parallelisable solution for screening target genes and holds the potential to unravel genes that can enhance the secretory capacity of CHO cells.
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dos Santos R, Rosa SA, Aires-Barros MR, Tover A, Azevedo AM. Phenylboronic acid as a multi-modal ligand for the capture of monoclonal antibodies: Development and optimization of a washing step. J Chromatogr A 2014; 1355:115-24. [DOI: 10.1016/j.chroma.2014.06.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 05/29/2014] [Accepted: 06/02/2014] [Indexed: 10/25/2022]
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10
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Nagirnaja L, Venclovas Č, Rull K, Jonas KC, Peltoketo H, Christiansen OB, Kairys V, Kivi G, Steffensen R, Huhtaniemi IT, Laan M. Structural and functional analysis of rare missense mutations in human chorionic gonadotrophin β-subunit. Mol Hum Reprod 2012; 18:379-90. [PMID: 22554618 PMCID: PMC3389497 DOI: 10.1093/molehr/gas018] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Heterodimeric hCG is one of the key hormones determining early pregnancy success. We have previously identified rare missense mutations in hCGβ genes with potential pathophysiological importance. The present study assessed the impact of these mutations on the structure and function of hCG by applying a combination of in silico (sequence and structure analysis, molecular dynamics) and in vitro (co-immunoprecipitation, immuno- and bioassays) approaches. The carrier status of each mutation was determined for 1086 North-Europeans [655 patients with recurrent miscarriage (RM)/431 healthy controls from Estonia, Finland and Denmark] using PCR-restriction fragment length polymorphism. The mutation CGB5 p.Val56Leu (rs72556325) was identified in a single heterozygous RM patient and caused a structural hindrance in the formation of the hCGα/β dimer. Although the amount of the mutant hCGβ assembled into secreted intact hCG was only 10% compared with the wild-type, a stronger signaling response was triggered upon binding to its receptor, thus compensating the effect of poor dimerization. The mutation CGB8 p.Pro73Arg (rs72556345) was found in five heterozygotes (three RM cases and two control individuals) and was inherited by two of seven studied live born children. The mutation caused ∼50% of secreted β-subunits to acquire an alternative conformation, but did not affect its biological activity. For the CGB8 p.Arg8Trp (rs72556341) substitution, the applied in vitro methods revealed no alterations in the assembly of intact hCG as also supported by an in silico analysis. In summary, the accumulated data indicate that only mutations with neutral or mild functional consequences might be tolerated in the major hCGβ genes CGB5 and CGB8.
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Affiliation(s)
- Liina Nagirnaja
- Human Molecular Genetics Research Group, Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010 Tartu, Estonia
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11
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Fischer S, Charara N, Gerber A, Wölfel J, Schiedner G, Voedisch B, Geisse S. Transient recombinant protein expression in a human amniocyte cell line: The CAP-T® cell system. Biotechnol Bioeng 2012; 109:2250-61. [DOI: 10.1002/bit.24514] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Revised: 02/28/2012] [Accepted: 03/19/2012] [Indexed: 11/10/2022]
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Abstract
The first protocols describing transient gene expression in mammalian cells for the rapid generation of recombinant proteins emerged more than 10 years ago as an alternative to the establishment of stable, often amplified clonal cell lines, and relieved somewhat the bias against mammalian cell systems as being too complicated, labor intensive, and tedious to serve as a source for tool proteins in industrial research and academia. Over the past decade, these attempts have been refined and optimized, giving rise to expression protocols applicable in every lab in dependence on available tools, equipment, and envisaged outcome. This chapter summarizes the development of transient expression technologies over the past decade up to its current status and provides an outlook into what may be the future of transient technology development.
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13
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Abstract
In the past two decades, the production levels for monoclonal antibodies in mammalian expression systems have improved dramatically. Single cell productivity for monoclonal antibodies has increased 20-50 fold due to the improvements in expression hosts, expression vectors, cell culture media, and production processes. However, most of these improvements are proprietary to large pharmaceutical/biotech companies and involve large steel-tank bioreactors. Therefore, these processes are difficult for small companies and academic labs to reproduce. Transient expression in mammalian cells has recently been used very widely for monoclonal antibody expression. Cell line and expression vector engineering increased expression levels to several hundred milligrams per liter. The availability of highly effective transfection reagents and disposable bioreactors make the transient expression process an efficient and cost-effective way to make recombinant antibodies in large quantity. Here, we describe the protocols for small- to mid-scale transient expression of monoclonal antibodies in shake-flasks and for large-scale production in WAVE bioreactors.
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14
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Martinon F, Kaldma K, Sikut R, Culina S, Romain G, Tuomela M, Adojaan M, Männik A, Toots U, Kivisild T, Morin J, Brochard P, Delache B, Tripiciano A, Ensoli F, Stanescu I, Le Grand R, Ustav M. Persistent immune responses induced by a human immunodeficiency virus DNA vaccine delivered in association with electroporation in the skin of nonhuman primates. Hum Gene Ther 2010; 20:1291-307. [PMID: 19627235 DOI: 10.1089/hum.2009.044] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Strategies to improve vaccine efficacy are still required, especially in the case of chronic infections, including human immunodeficiency virus (HIV). DNA vaccines have potential advantages over conventional vaccines; however, low immunological efficacy has been demonstrated in many experiments involving large animals and in clinical trials. To improve the immunogenicity of DNA vaccines, we have designed a plasmid vector exploiting the binding capacity of the bovine papillomavirus E2 protein and we have used electroporation (EP) to increase DNA uptake after intradermal inoculation. We demonstrated, in nonhuman primates (NHPs), efficient induction of anti-HIV immunity with an improved DNA vaccine vector encoding an artificial fusion protein, consisting of several proteins and selected epitopes from HIV-1. We show that a DNA vaccine delivery method combining intradermal injection and noninvasive EP dramatically increased expression of the vaccine antigen selectively in the epidermis, and our observations strongly suggest the involvement of Langerhans cells in the strength and quality of the anti-HIV immune response. Although the humoral responses to the vaccine were transient, the cellular responses were exceptionally robust and persisted, at high levels, more than 2 years after the last vaccine boost. The immune responses were characterized by the induction of significant proportions of T cells producing both interferon-gamma and interleukin-2 cytokines, in both subpopulations, CD4(+) and CD8(+). This strategy is an attractive approach for vaccination in humans because of its high efficacy and the possible use of newly developed devices for EP.
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Affiliation(s)
- Frédéric Martinon
- Division of Immunovirology, Life Sciences Program (DSV), Institute for Emerging Diseases and Innovative Therapies, Atomic Energy Commission (CEA), Fontenay aux Roses, France.
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15
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Effective formation of the segregation-competent complex determines successful partitioning of the bovine papillomavirus genome during cell division. J Virol 2010; 84:11175-88. [PMID: 20810736 DOI: 10.1128/jvi.01366-10] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Effective segregation of the bovine papillomavirus type 1 (BPV1), Epstein-Barr virus (EBV), and Kaposi's sarcoma-associated human herpesvirus type 8 (KSHV) genomes into daughter cells is mediated by a single viral protein that tethers viral genomes to host mitotic chromosomes. The linker proteins that mediate BPV1, EBV, and KSHV segregation are E2, LANA1, and EBNA1, respectively. The N-terminal transactivation domain of BPV1 E2 is responsible for chromatin attachment and subsequent viral genome segregation. Because E2 transcriptional activation and chromatin attachment functions are not mutually exclusive, we aimed to determine the requirement of these activities during segregation by analyzing chimeric E2 proteins. This approach allowed us to separate the two activities. Our data showed that attachment of the segregation protein to chromatin is not sufficient for proper segregation. Rather, formation of a segregation-competent complex which carries multiple copies of the segregation protein is required. Complementation studies of E2 functional domains indicated that chromatin attachment and transactivation functions must act in concert to ensure proper plasmid segregation. These data indicate that there are specific interactions between linker molecules and transcription factors/complexes that greatly increase segregation-competent complex formation. We also showed, using hybrid E2 molecules, that restored segregation function does not involve interactions with Brd4.
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Reflections on more than 10 years of TGE approaches. Protein Expr Purif 2009; 64:99-107. [DOI: 10.1016/j.pep.2008.10.017] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2008] [Revised: 10/21/2008] [Accepted: 10/21/2008] [Indexed: 11/22/2022]
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Papillomavirus DNA replication — From initiation to genomic instability. Virology 2009; 384:360-8. [DOI: 10.1016/j.virol.2008.11.032] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2008] [Accepted: 11/18/2008] [Indexed: 12/25/2022]
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Abstract
The timely availability of recombinant proteins in sufficient quantity and of validated quality is of utmost importance in driving drug discovery and the development of low molecular weight compounds, as well as for biotherapeutics. Transient gene expression (TGE) in mammalian cells has emerged as a promising technology for protein generation over the past decade as TGE meets all the prerequisites with respect to quantity and quality of the product as well as cost-effectiveness and speed of the process. Optimized protocols have been developed for both HEK293 and CHO cell lines which allow protein production at any desired scale up to >100 l and in milligram to gram quantities. Along with an overview on current scientific and technological knowledge, detailed protocols for expression of recombinant proteins on small, medium, and large scale are discussed in the following chapter.
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Skalsky RL, Hu J, Renne R. Analysis of viral cis elements conferring Kaposi's sarcoma-associated herpesvirus episome partitioning and maintenance. J Virol 2007; 81:9825-37. [PMID: 17626102 PMCID: PMC2045406 DOI: 10.1128/jvi.00842-07] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Maintenance of Kaposi's sarcoma-associated herpesvirus (KSHV) episomes in latently infected cells is dependent on the latency-associated nuclear antigen (LANA). LANA binds to the viral terminal repeats (TR), leading to recruitment of cellular origin recognition complex proteins. Additionally, LANA tethers episomes to chromosomes via interactions with histones H2A and H2B (A. J. Barbera et al., Science 311:856-861, 2006). Despite these molecular details, less is known about how episomes are established after de novo infection. To address this, we measured short-term retention rates of green fluorescent protein-expressing replicons in proliferating lymphoid cells. In the absence of antibiotic selection, LANA significantly reduced the loss rate of TR-containing replicons. Additionally, we found that LANA can support long-term stability of KSHV replicons for more than 2 months under nonselective conditions. Analysis of cis elements within TR that confer episome replication and partitioning revealed that these activities can occur independently, and furthermore, both events contribute to episome stability. We found that replication-deficient plasmids containing LANA binding sites (LBS1/2) exhibited measurable retention rates in the presence of LANA. To confirm these observations, we uncoupled KSHV replication and partitioning by constructing hybrid origins containing the Epstein-Barr virus (EBV) dyad symmetry for plasmid replication and KSHV LBS1/2. We demonstrate that multiple LBS1/2 function in a manner analogous to that of the EBV family of repeats by forming an array of LANA binding sites for partitioning of KSHV genomes. Our data suggest that the efficiency with which KSHV establishes latency is dependent on multiple LANA activities, which stabilize viral genomes early after de novo infection.
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Affiliation(s)
- Rebecca L Skalsky
- Department of Molecular Genetics and Microbiology, and Shands Cancer Center, University of Florida, 1613 Mowry Road, Gainesville, FL 32610-3633, USA
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Ilves I, Mäemets K, Silla T, Janikson K, Ustav M. Brd4 is involved in multiple processes of the bovine papillomavirus type 1 life cycle. J Virol 2006; 80:3660-5. [PMID: 16537635 PMCID: PMC1440376 DOI: 10.1128/jvi.80.7.3660-3665.2006] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Brd4 protein has been proposed to act as a cellular receptor for the bovine papillomavirus type 1 (BPV1) E2 protein in the E2-mediated chromosome attachment and mitotic segregation of viral genomes. Here, we provide data that show the involvement of Brd4 in multiple early functions of the BPV1 life cycle, suggest a Brd4-dependent mechanism for E2-dependent transcription activation, and indicate the role of Brd4 in papillomavirus and polyomavirus replication as well as cell-specific utilization of Brd4-linked features in BPV1 DNA replication. Our data also show the potential therapeutic value of the disruption of the E2-Brd4 interaction for the development of antiviral drugs.
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Affiliation(s)
- Ivar Ilves
- Institute of Technology, University of Tartu, Tartu 50411, Estonia
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