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Meenakshi Sundaram DN, Bahadur K C R, Fu W, Uludağ H. An optimized polymeric delivery system for piggyBac transposition. Biotechnol Bioeng 2024; 121:1503-1517. [PMID: 38372658 DOI: 10.1002/bit.28665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 12/14/2023] [Accepted: 01/17/2024] [Indexed: 02/20/2024]
Abstract
The piggyBac transposon/transposase system has been explored for long-term, stable gene expression to execute genomic integration of therapeutic genes, thus emerging as a strong alternative to viral transduction. Most studies with piggyBac transposition have employed physical methods for successful delivery of the necessary components of the piggyBac system into the cells. Very few studies have explored polymeric gene delivery systems. In this short communication, we report an effective delivery system based on low molecular polyethylenimine polymer with lipid substitution (PEI-L) capable of delivering three components, (i) a piggyBac transposon plasmid DNA carrying a gene encoding green fluorescence protein (PB-GFP), (ii) a piggyBac transposase plasmid DNA or mRNA, and (iii) a 2 kDa polyacrylic acid as additive for transfection enhancement, all in a single complex. We demonstrate an optimized formulation for stable GFP expression in two model cell lines, MDA-MB-231 and SUM149 recorded till day 108 (3.5 months) and day 43 (1.4 months), respectively, following a single treatment with very low cell number as starting material. Moreover, the stability of the transgene (GFP) expression mediated by piggyBac/PEI-L transposition was retained following three consecutive cryopreservation cycles. The success of this study highlights the feasibility and potential of employing a polymeric delivery system to obtain piggyBac-based stable expression of therapeutic genes.
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Affiliation(s)
| | - Remant Bahadur K C
- Department of Chemical and Materials Engineering, Faculty of Engineering, University of Alberta, Edmonton, Alberta, Canada
| | - Wei Fu
- Institute of Pediatric Translational Medicine, Shanghai Children's Medical Center, Shanghai Jiao Tong University, Shanghai, China
| | - Hasan Uludağ
- Department of Chemical and Materials Engineering, Faculty of Engineering, University of Alberta, Edmonton, Alberta, Canada
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta, Canada
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Majumdar S, Desai R, Hans A, Dandekar P, Jain R. From Efficiency to Yield: Exploring Recent Advances in CHO Cell Line Development for Monoclonal Antibodies. Mol Biotechnol 2024:10.1007/s12033-024-01060-6. [PMID: 38363529 DOI: 10.1007/s12033-024-01060-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 12/29/2023] [Indexed: 02/17/2024]
Abstract
The increasing demand for biosimilar monoclonal antibodies (mAbs) has prompted the development of stable high-producing cell lines while simultaneously decreasing the time required for screening. Existing platforms have proven inefficient, resulting in inconsistencies in yields, growth characteristics, and quality features in the final mAb products. Selecting a suitable expression host, designing an effective gene expression system, developing a streamlined cell line generation approach, optimizing culture conditions, and defining scaling-up and purification strategies are all critical steps in the production of recombinant proteins, particularly monoclonal antibodies, in mammalian cells. As a result, an active area of study is dedicated to expression and optimizing recombinant protein production. This review explores recent breakthroughs and approaches targeted at accelerating cell line development to attain efficiency and consistency in the synthesis of therapeutic proteins, specifically monoclonal antibodies. The primary goal is to bridge the gap between rising demand and consistent, high-quality mAb production, thereby benefiting the healthcare and pharmaceutical industries.
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Affiliation(s)
- Sarmishta Majumdar
- Department of Biological Science and Biotechnology, Institute of Chemical Technology, Mumbai, 400019, India
| | - Ranjeet Desai
- Department of Pharmaceutical Sciences and Technology, Institute of Chemical Technology, Mumbai, 400019, India
| | - Aakarsh Hans
- Department of Pharmaceutical Sciences and Technology, Institute of Chemical Technology, Mumbai, 400019, India
| | - Prajakta Dandekar
- Department of Pharmaceutical Sciences and Technology, Institute of Chemical Technology, Mumbai, 400019, India.
| | - Ratnesh Jain
- Department of Biological Science and Biotechnology, Institute of Chemical Technology, Mumbai, 400019, India.
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Wang XY, Zhang WL, Zhang X, Fu YS, Wang HM, Sun QL, Li Q, Jia YL, Zhang JH, Wang TY. Combination of MAR and intron increase transgene expression of episomal vectors in CHO cells. Biotechnol J 2023; 18:e2200643. [PMID: 37551822 DOI: 10.1002/biot.202200643] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 07/22/2023] [Accepted: 08/03/2023] [Indexed: 08/09/2023]
Abstract
Previous work has shown that the EF-1α promoter of episomal vectors maintains high-level transgene expression in stably transfected Chinese hamster ovary (CHO) cells. However, the transgene expression levels need to be further increased. Here, we first incorporated matrix attachment regions (MARs), ubiquitous chromatin opening element (UCOE), stabilizing anti repressor elements 40 (STAR 40) elements into episomal vector at different sites and orientations, and systemically assessed their effects on transgene expression in transfected CHO-K1 cells. Results showed that enhanced green fluorescent protein (eGFP) expression levels increased remarkably when MAR X-29 was inserted upstream of the promoter, followed by the insertion of MAR1 downstream of the poly A, and the orientation had no significant effect. Moreover, MAR X-29 combined with human cytomegalovirus intron (hCMVI) yielded the highest transgene expression levels (4.52-fold). Transgene expression levels were not exclusively dependent on transgene copy numbers and were not related to the mRNA expression level. In addition, vector with MAR X-29+hCMVI can induce herpes simplex virus thymidine kinase (HSV-TK) protein expression, and the HSV-TK protein showed a cell-killing effect and an obvious bystander effect on HCT116 cells. In conclusion, the combination of MAR X-29 and hCMV intron can achieve high efficiency transgene expression mediated by episomal vectors in CHO-K1 cells.
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Affiliation(s)
- Xiao-Yin Wang
- School of Basic Medical Science, Xinxiang Medical University, Xinxiang, China
- International Joint Research Laboratory for Recombinant Pharmaceutical Protein Expression System of Henan, Xinxiang Medical University, Xinxiang, China
| | - Wei-Li Zhang
- School of Basic Medical Science, Xinxiang Medical University, Xinxiang, China
- Center for Medical Genetics, Nanyang Second General Hospital, Nanyang, China
| | - Xi Zhang
- College of Pharmacy, Xinxiang Medical University, Xinxiang, China
| | - Yu-Shun Fu
- School of Basic Medical Science, Xinxiang Medical University, Xinxiang, China
| | - Hao-Min Wang
- School of Basic Medical Science, Xinxiang Medical University, Xinxiang, China
| | - Qiu-Li Sun
- International Joint Research Laboratory for Recombinant Pharmaceutical Protein Expression System of Henan, Xinxiang Medical University, Xinxiang, China
| | - Qin Li
- School of Basic Medical Science, Xinxiang Medical University, Xinxiang, China
| | - Yan-Long Jia
- College of Pharmacy, Xinxiang Medical University, Xinxiang, China
| | - Jun-He Zhang
- Institutes of Health Central Plains, Xinxiang Medical University, Xinxiang, China
| | - Tian-Yun Wang
- School of Basic Medical Science, Xinxiang Medical University, Xinxiang, China
- International Joint Research Laboratory for Recombinant Pharmaceutical Protein Expression System of Henan, Xinxiang Medical University, Xinxiang, China
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Zhang M, Ehmann ME, Matukumalli S, Boob AG, Gilbert DM, Zhao H. SHIELD: a platform for high-throughput screening of barrier-type DNA elements in human cells. Nat Commun 2023; 14:5616. [PMID: 37699958 PMCID: PMC10497619 DOI: 10.1038/s41467-023-41468-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 09/04/2023] [Indexed: 09/14/2023] Open
Abstract
Chromatin boundary elements contribute to the partitioning of mammalian genomes into topological domains to regulate gene expression. Certain boundary elements are adopted as DNA insulators for safe and stable transgene expression in mammalian cells. These elements, however, are ill-defined and less characterized in the non-coding genome, partially due to the lack of a platform to readily evaluate boundary-associated activities of putative DNA sequences. Here we report SHIELD (Site-specific Heterochromatin Insertion of Elements at Lamina-associated Domains), a platform tailored for the high-throughput screening of barrier-type DNA elements in human cells. SHIELD takes advantage of the high specificity of serine integrase at heterochromatin, and exploits the natural heterochromatin spreading inside lamina-associated domains (LADs) for the discovery of potent barrier elements. We adopt SHIELD to evaluate the barrier activity of 1000 DNA elements in a high-throughput manner and identify 8 candidates with barrier activities comparable to the core region of cHS4 element in human HCT116 cells. We anticipate SHIELD could facilitate the discovery of novel barrier DNA elements from the non-coding genome in human cells.
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Affiliation(s)
- Meng Zhang
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Mary Elisabeth Ehmann
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Srija Matukumalli
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Aashutosh Girish Boob
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - David M Gilbert
- San Diego Biomedical Research Institute, San Diego, CA, 92121, USA
| | - Huimin Zhao
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
- Department of Chemistry, Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
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Cepleanu-Pascu IA, Stan M, Cocioba S, Stoica I. Easy method for six-fragment Golden Gate Assembly of modular vectors. Biotechniques 2023; 74:85-99. [PMID: 36691899 DOI: 10.2144/btn-2022-0041] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Efficient cloning techniques are a requirement for synthetic biology. This study provides a simplified cloning method based on Golden Gate Assembly that can be used for rapid vector construction. The building of multiple expression vectors with customizable modules is achieved in a timely manner with minimal hands-on time by removing unnecessary steps in the workflow. The authors constructed a total of 21 mammalian episomal expression vectors and conducted a fluorescence expression comparison for different regulatory region combinations post-transfection in HEK293T and HEPG2 cells. Screening revealed that using the EF-1α promoter in combination with the bovine growth hormone polyadenylation sequence seemed to perform best in the types of cells tested compared with other variants.
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Affiliation(s)
| | - Miruna Stan
- Department of Biochemistry & Molecular Biology, Faculty of Biology, University of Bucharest, Bucharest, Romania
| | | | - Ileana Stoica
- Department of Genetics, Faculty of Biology, University of Bucharest, Bucharest, Romania
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Khan SU, Khan MU, Khan MI, Kalsoom F, Zahra A. Current Landscape and Emerging Opportunities of Gene Therapy with Non-viral Episomal Vectors. Curr Gene Ther 2023; 23:135-147. [PMID: 36200188 DOI: 10.2174/1566523222666221004100858] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 06/10/2022] [Accepted: 06/10/2022] [Indexed: 11/22/2022]
Abstract
Gene therapy has proven to be extremely beneficial in the management of a wide range of genetic disorders for which there are currently no or few effective treatments. Gene transfer vectors are very significant in the field of gene therapy. It is possible to attach a non-viral attachment vector to the donor cell chromosome instead of integrating it, eliminating the negative consequences of both viral and integrated vectors. It is a safe and optimal express vector for gene therapy because it does not cause any adverse effects. However, the modest cloning rate, low expression, and low clone number make it unsuitable for use in gene therapy. Since the first generation of non-viral attachment episomal vectors was constructed, various steps have been taken to regulate their expression and stability, such as truncating the MAR element, lowering the amount of CpG motifs, choosing appropriate promoters and utilizing regulatory elements. This increases the transfection effectiveness of the non-viral attachment vector while also causing it to express at a high level and maintain a high level of stability. A vector is a genetic construct commonly employed in gene therapy to treat various systemic disorders. This article examines the progress made in the development of various optimization tactics for nonviral attachment vectors and the future applications of these vectors in gene therapy.
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Affiliation(s)
- Safir Ullah Khan
- Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei 230027, People's Republic of China
| | - Munir Ullah Khan
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, International Research Center for X Polymers, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310027 China
| | - Muhammad Imran Khan
- School of Life Sciences and Medicine, University of Science and Technology of China,Hefei 230027,People's Republic of China
- Department of Pathology, District Headquarters Hospital Jhang 35200, Punjab Province, Islamic Republic of Pakistan
| | - Fadia Kalsoom
- Department of Pathology, District Headquarters Hospital Jhang 35200, Punjab Province, Islamic Republic of Pakistan
| | - Aqeela Zahra
- Department of Family and Community Medicine. College of Medicine, University of Ha'il, Ha'il 81451, Saudi Arabia
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Hussein MK, Papež M, Dhiman H, Baumann M, Galosy S, Borth N. In silico design of CMV promoter binding oligonucleotides and their impact on inhibition of gene expression in Chinese hamster ovary cells. J Biotechnol 2022; 359:185-193. [DOI: 10.1016/j.jbiotec.2022.10.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 09/30/2022] [Accepted: 10/04/2022] [Indexed: 10/31/2022]
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Li ZM, Fan ZL, Wang XY, Wang TY. Factors Affecting the Expression of Recombinant Protein and Improvement Strategies in Chinese Hamster Ovary Cells. Front Bioeng Biotechnol 2022; 10:880155. [PMID: 35860329 PMCID: PMC9289362 DOI: 10.3389/fbioe.2022.880155] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 06/01/2022] [Indexed: 01/20/2023] Open
Abstract
Recombinant therapeutic proteins (RTPs) are important parts of biopharmaceuticals. Chinese hamster ovary cells (CHO) have become the main cell hosts for the production of most RTPs approved for marketing because of their high-density suspension growth characteristics, and similar human post-translational modification patterns et al. In recent years, many studies have been performed on CHO cell expression systems, and the yields and quality of recombinant protein expression have been greatly improved. However, the expression levels of some proteins are still low or even difficult-to express in CHO cells. It is urgent further to increase the yields and to express successfully the “difficult-to express” protein in CHO cells. The process of recombinant protein expression of is a complex, involving multiple steps such as transcription, translation, folding processing and secretion. In addition, the inherent characteristics of molecular will also affect the production of protein. Here, we reviewed the factors affecting the expression of recombinant protein and improvement strategies in CHO cells.
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Affiliation(s)
- Zheng-Mei Li
- School of Life Science and Technology, Xinxiang Medical University, Xinxiang, China
- International Joint Research Laboratory for Recombinant Pharmaceutical Protein Expression System of Henan, Xinxiang, China
| | - Zhen-Lin Fan
- International Joint Research Laboratory for Recombinant Pharmaceutical Protein Expression System of Henan, Xinxiang, China
- Institutes of Health Central Plain, Xinxiang Medical University, Xinxiang, China
| | - Xiao-Yin Wang
- International Joint Research Laboratory for Recombinant Pharmaceutical Protein Expression System of Henan, Xinxiang, China
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, China
| | - Tian-Yun Wang
- International Joint Research Laboratory for Recombinant Pharmaceutical Protein Expression System of Henan, Xinxiang, China
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, China
- *Correspondence: Tian-Yun Wang,
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Abstract
INTRODUCTION Lentiviral vectors have emerged as powerful vectors for vaccination, due to their high efficiency to transduce dendritic cells and to induce long-lasting humoral immunity, CD8+ T cells, and effective protection in numerous preclinical animal models of infection and oncology. AREAS COVERED Here, we reviewed the literature, highlighting the relevance of lentiviral vectors in vaccinology. We recapitulated both their virological and immunological aspects of lentiviral vectors. We compared lentiviral vectors to the gold standard viral vaccine vectors, i.e. adenoviral vectors, and updated the latest results in lentiviral vector-based vaccination in preclinical models. EXPERT OPINION Lentiviral vectors are non-replicative, negligibly inflammatory, and not targets of preexisting immunity in human populations. These are major characteristics to consider in vaccine development. The potential of lentiviral vectors to transduce non-dividing cells, including dendritic cells, is determinant in their strong immunogenicity. Notably, lentiviral vectors can be engineered to target antigen expression to specific host cells. The very weak inflammatory properties of these vectors allow their use in mucosal vaccination, with particular interest in infectious diseases that affect the lungs or brain, including COVID-19. Recent results in various preclinical models have reinforced the interest of these vectors in prophylaxis against infectious diseases and in onco-immunotherapy.
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Affiliation(s)
- Min-Wen Ku
- Virology Department, Institut Pasteur-TheraVectys Joint Lab, Paris, France
| | - Pierre Charneau
- Virology Department, Institut Pasteur-TheraVectys Joint Lab, Paris, France
| | - Laleh Majlessi
- Virology Department, Institut Pasteur-TheraVectys Joint Lab, Paris, France
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Savar NS, Vallet T, Azizi M, Arashkia A, Lundstrom K, Vignuzzi M, Niknam HM. Quantitative evaluation of PpSP15-LmSTI1 fusion gene expression following transfection with an alphavirus-derived self-amplifying mRNA and conventional DNA vaccine platforms. Mol Cell Probes 2021; 59:101749. [PMID: 34214632 DOI: 10.1016/j.mcp.2021.101749] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 06/24/2021] [Accepted: 06/27/2021] [Indexed: 12/28/2022]
Abstract
New vaccine platforms are crucial to address complex parasitic infections such as cutaneous leishmaniasis. Self-amplifying mRNA (SAM) based vaccines represent the next generation nucleic acid-based platform. In the present study, we compared the expression levels of PpSP15-LmSTI1 fusion gene in BHK-21 cells following transfection with Semliki Forest virus (SFV)-derived SAM, SFV-derived plasmid DNA (pSFV-PD) and conventional plasmid DNA (pcDNA3.1+). PpSP15-LmSTI1 fusion gene expression levels were evaluated at different time points, using quantitative Real-time PCR. All data were validated and normalized by two internal control genes. According to the results, mean values of relative expression were significantly higher for SFV-PD SAM/fusion than pcDNA/fusion and pSFV-PD/fusion at all concentrations and time points. Our results showed that higher levels of PpSp15-LmSTI1 antigen expression could be achieved using a SAM vector than pcDNA and pSFV-PD, making it a valuable and efficient alternative to conventional plasmid DNA-based vaccines against leishmaniasis.
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Affiliation(s)
| | - Thomas Vallet
- Institut Pasteur, Viral Populations and Pathogenesis Unit, Centre National de La Recherche Scientifique UMR, 3569, Paris, France
| | - Masoumeh Azizi
- Molecular Medicine Department, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | - Arash Arashkia
- Virology Department, Pasteur Institute of Iran, Tehran, Iran
| | | | - Marco Vignuzzi
- Institut Pasteur, Viral Populations and Pathogenesis Unit, Centre National de La Recherche Scientifique UMR, 3569, Paris, France.
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Dou Y, Lin Y, Wang TY, Wang XY, Jia YL, Zhao CP. The CAG promoter maintains high-level transgene expression in HEK293 cells. FEBS Open Bio 2020; 11:95-104. [PMID: 33155423 PMCID: PMC7780116 DOI: 10.1002/2211-5463.13029] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 10/03/2020] [Accepted: 11/04/2020] [Indexed: 12/11/2022] Open
Abstract
The vast majority of therapeutic recombinant proteins are produced in mammalian cell lines. However, proteins generated in nonhuman cell lines, such as Chinese hamster ovary (CHO) cells, are decorated with human‐like glycan structures that differ from those of human cells, and these may induce immunogenic responses in human cells. Human embryonic kidney cells (HEK293F) are also extensively used as hosts for the expression of recombinant therapeutic proteins, but their utility is limited by the low expression of transgenes in these cells. Here, we investigated recombinant protein expression from eight frequently used promoters in transfected HEK293F cells. The expression levels and stability of the transgenes were evaluated by flow cytometry and qRT‐PCR. The most efficient expression (in terms of both mRNA and protein yields) was achieved using a cytomegalovirus (CMV) major immediate‐early enhancer combined with the chicken beta‐actin promoter (CAG) promoter, as compared to all other tested promoters under both transient and stable transfection conditions. In addition, application of mild hypothermia (i.e., 33 °C) after transfection improved the positive effect of the CMV enhancer fused to the chicken beta‐actin promoter (CAG promoter) on enhanced green fluorescent protein (eGFP) expression. Although the temperature sensitivity of the CMV promoter is greater than that of CAG promoter, recombinant protein levels were still highest when expression was driven by the CAG promoter. When eGFP was replaced with hepatitis B surface antigen, the CAG promoter still showed the highest transgene expression. In conclusion, our data show that the CAG promoter is a strong promoter for recombinant protein expression in HEK293F cells.
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Affiliation(s)
- Yuanyuan Dou
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, China.,Henan Collaborative Innovation Center of Molecular Diagnosis and Laboratory Medicine, Xinxiang, China
| | - Yan Lin
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, China
| | - Tian-Yun Wang
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, China
| | - Xiao-Yin Wang
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, China
| | - Yan-Long Jia
- Henan Collaborative Innovation Center of Molecular Diagnosis and Laboratory Medicine, Xinxiang, China
| | - Chun-Peng Zhao
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, China
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Millen S, Meretuk L, Göttlicher T, Schmitt S, Fleckenstein B, Thoma-Kress AK. A novel positive feedback-loop between the HTLV-1 oncoprotein Tax and NF-κB activity in T-cells. Retrovirology 2020; 17:30. [PMID: 32912211 PMCID: PMC7488018 DOI: 10.1186/s12977-020-00538-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 08/28/2020] [Indexed: 12/30/2022] Open
Abstract
Background Human T-cell leukemia virus type 1 (HTLV-1) infects primarily CD4+ T-lymphocytes and evoques severe diseases, predominantly Adult T-Cell Leukemia/ Lymphoma (ATL/L) and HTLV-1-associated Myelopathy/ Tropical Spastic Paraparesis (HAM/TSP). The viral transactivator of the pX region (Tax) is important for initiating malignant transformation, and deregulation of the major signaling pathway nuclear factor of kappa B (NF-κB) by Tax represents a hallmark of HTLV-1 driven cancer. Results Here we found that Tax mutants which are defective in NF-κB signaling showed diminished protein expression levels compared to Tax wildtype in T-cells, whereas Tax transcript levels were comparable. Strikingly, constant activation of NF-κB signaling by the constitutive active mutant of inhibitor of kappa B kinase (IKK2, IKK-β), IKK2-EE, rescued protein expression of the NF-κB defective Tax mutants M22 and K1-10R and even increased protein levels of Tax wildtype in various T-cell lines while Tax transcript levels were only slightly affected. Using several Tax expression constructs, an increase of Tax protein occurred independent of Tax transcripts and independent of the promoter used. Further, Tax and M22 protein expression were strongly enhanced by 12-O-Tetradecanoylphorbol-13-Acetate [TPA; Phorbol 12-myristate 13-acetate (PMA)]/ ionomycin, inducers of NF-κB and cytokine signaling, but not by tumor necrosis factor alpha (TNF-α). On the other hand, co-expression of Tax with a dominant negative inhibitor of κB, IκBα-DN, or specific inhibition of IKK2 by the compound ACHP, led to a vast decrease in Tax protein levels to some extent independent of Tax transcripts in transiently transfected and Tax-transformed T-cells. Cycloheximide chase experiments revealed that co-expression of IKK2-EE prolongs the half-life of M22, and constant repression of NF-κB signaling by IκBα-DN strongly reduces protein stability of Tax wildtype suggesting that NF-κB activity is required for Tax protein stability. Finally, protein expression of Tax and M22 could be recovered by NH4Cl and PYR-41, inhibitors of the lysosome and the ubiquitin-activating enzyme E1, respectively. Conclusions Together, these findings suggest that Tax’s capability to induce NF-κB is critical for protein expression and stabilization of Tax itself. Overall, identification of this novel positive feedback loop between Tax and NF-κB in T-cells improves our understanding of Tax-driven transformation.
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Affiliation(s)
- Sebastian Millen
- Institute of Clinical and Molecular Virology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Lina Meretuk
- Institute of Clinical and Molecular Virology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Tim Göttlicher
- Institute of Clinical and Molecular Virology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Sarah Schmitt
- Institute of Clinical and Molecular Virology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Bernhard Fleckenstein
- Institute of Clinical and Molecular Virology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Andrea K Thoma-Kress
- Institute of Clinical and Molecular Virology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany.
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Fusion with matrix attachment regions enhances expression of recombinant protein in human HT-1080 cells. J Biosci Bioeng 2020; 130:533-538. [PMID: 32773266 DOI: 10.1016/j.jbiosc.2020.07.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 07/09/2020] [Accepted: 07/09/2020] [Indexed: 11/23/2022]
Abstract
Like endogenous proteins, recombinant foreign proteins produced in human cell lines also need post-translational modifications. However, high and long-term expression of a gene of interest (GOI) presents significant challenges for recombinant protein production in human cells. In this work, the effect of human matrix attachment region elements (MARs), including the β-globin MAR (gMAR), chicken lysozyme MAR (cMAR), and a combination of these two, on the stable expression of GOI was assessed in human HT-1080 cells. After transfection with vectors containing the MAR elements and eGFP, stably HT-1080 cell pools were obtained under selective pressure. eGFP protein expression was analyzed by flow cytometry, while transgene copy number and eGFP mRNA expression levels were determined with qPCR and qRT-PCR technology. We found that MARs could not enhance transfection efficiency, but gMAR could significantly increase eGFP expression in stable HT-1080 cell pools by approximately 2.69-fold. Moreover, gMAR could also increase eGFP expression stability during long-term culture. Lastly, we showed that the effect of the MARs on transgenes was related to the gene copy number. In summary, this study found that MARs could both enhance the transgene expression and stability in HT-1080 cells.
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14
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Effects of viral promoters, the Woodchuck hepatitis post-transcriptional regulatory element, and weakened antibiotic resistance markers on transgene expression in Chinese hamster ovary cells. Process Biochem 2020. [DOI: 10.1016/j.procbio.2020.04.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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15
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Yi DD, Wang XY, Zhang WL, Wang M, Zhang JH, Wang TY. Construction of an expression vector mediated by the dual promoter for prokaryotic and mammalian cell expression system. Mol Biol Rep 2020; 47:5185-5190. [PMID: 32564228 DOI: 10.1007/s11033-020-05593-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Accepted: 06/17/2020] [Indexed: 12/17/2022]
Abstract
The aim of this study was to construct an expression vector mediated by the dual promoter that can simultaneously drive the recombinant protein production in eukaryotic and prokaryotic cells. The prokaryotic T7 promoter and ribosome binding site (RBS) was cloned downstream of CMV promoter in the eukaryotic expression vector pIRES-neo, and T7 termination sequence was inserted upstream of neomycin phosphotransferase gene to generate the dual promoter vector. The enhanced green fluorescent protein (eGFP) gene was used as reporter gene. Then, the resultant vector was transfected into Chinese hamster ovary (CHO) cells and transformed into Escherichia coli (E. coli) BL21, and the eGFP expression levels were analyzed by fluorescence microscopy, flow cytometry and Western blot, respectively. Fluorescence microscopy revealed that the eGFP was expressed in both CHO cells and E. coli BL21. Flow cytometry showed that the eGFP expression level had no significant difference between the dual promoter vector and control vector in transfected CHO cells. Western blot analysis indicated the eGFP expressed in transformed E. coli. In conclusion, a prokaryotic-eukaryotic double expression vector was successfully constructed, which has potential applications in rapid cloning and expression of recombinant proteins in both prokaryotic and eukaryotic expression systems.
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Affiliation(s)
- Dan-Dan Yi
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Jinsui Road, Xinxiang, 453003, Henan, China
| | - Xiao-Yin Wang
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Jinsui Road, Xinxiang, 453003, Henan, China
- International Joint Research Laboratory for Recombinant Pharmaceutical Protein Expression System of Henan, Xinxiang Medical University, Xinxiang, 453003, Henan, China
| | - Wei-Li Zhang
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Jinsui Road, Xinxiang, 453003, Henan, China
| | - Meng Wang
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Jinsui Road, Xinxiang, 453003, Henan, China
- International Joint Research Laboratory for Recombinant Pharmaceutical Protein Expression System of Henan, Xinxiang Medical University, Xinxiang, 453003, Henan, China
| | - Jun-He Zhang
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Jinsui Road, Xinxiang, 453003, Henan, China
| | - Tian-Yun Wang
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Jinsui Road, Xinxiang, 453003, Henan, China.
- International Joint Research Laboratory for Recombinant Pharmaceutical Protein Expression System of Henan, Xinxiang Medical University, Xinxiang, 453003, Henan, China.
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16
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Wang TY, Guo X. Expression vector cassette engineering for recombinant therapeutic production in mammalian cell systems. Appl Microbiol Biotechnol 2020; 104:5673-5688. [PMID: 32372203 DOI: 10.1007/s00253-020-10640-w] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 04/13/2020] [Accepted: 04/20/2020] [Indexed: 12/16/2022]
Abstract
Human tissue plasminogen activator was the first recombinant therapy protein that successfully produced in Chinese hamster ovary cells in 1986 and approved for clinical use. Since then, more and more therapeutic proteins are being manufactured in mammalian cells, and the technologies for recombinant protein production in this expression system have developed rapidly, with the optimization of both upstream and downstream processes. One of the most promising strategies is expression vector cassette optimization based on the expression vector cassette. In this review paper, these approaches and developments are summarized, and the future strategy on the utilizing of expression cassettes for the production of recombinant therapeutic proteins in mammalian cells is discussed.
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Affiliation(s)
- Tian-Yun Wang
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, 453003, Henan, China.
- International Joint Research Laboratory for Recombinant Pharmaceutical Protein Expression System of Henan, Xinxiang Medical University, Xinxiang, 453003, Henan, China.
| | - Xiao Guo
- International Joint Research Laboratory for Recombinant Pharmaceutical Protein Expression System of Henan, Xinxiang Medical University, Xinxiang, 453003, Henan, China
- Perildicals Publishing House, Xinxiang Medical University, Xinxiang, Henan, China
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17
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Xu ZJ, Jia YL, Wang M, Yi DD, Zhang WL, Wang XY, Zhang JH. Effect of promoter, promoter mutation and enhancer on transgene expression mediated by episomal vectors in transfected HEK293, Chang liver and primary cells. Bioengineered 2020; 10:548-560. [PMID: 31668126 PMCID: PMC6844389 DOI: 10.1080/21655979.2019.1684863] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The episomal vector cannot integrate into the host cell chromosome, which has no potential risk in gene therapy. However, the low level of transgene expression driven by episomal vectors needs to be solved. In this study, we investigated the effects of enhancers, promoters and promoter variants on transgene expression levels driven by episomal vectors in HEK293, Chang liver and primary cells. Results showed that all eight cis-acting elements used could increase transfection efficiency and transient eGFP expression in transfected HEK293 and Chang liver cells. In stably transfected mammalian cells, the elongation factor-1 alpha (EF-1α) promoter and mutant-404 showed high and stable transgene expression. The mechanisms might be related to the type and quantity of transcription factor regulatory elements. Moreover, quantitative reverse transcription polymerase chain reaction analysis showed that mRNA expression levels were not directly proportional to protein expression levels. Furthermore, the EF-1α promoter conferred high transgene expression levels in primary cells, and the plasmid was also present in the episomal state. Taken together, these results provided valuable information for improving transgene expression with episomal vectors in mammalian cells.
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Affiliation(s)
- Zhong-Jie Xu
- Life Science and Technology, Xinxiang Medical University, Xinxiang, Henan, China
| | - Yan-Long Jia
- Pharmacy collage, Xinxiang Medical University, Xinxiang, Henan, China
| | - Meng Wang
- International Joint Research Laboratory for Recombiant Pharmaceutical Protein Expression System of Henan, Xinxiang Medical University, Xinxiang, Henan, China
| | - Dan-Dan Yi
- International Joint Research Laboratory for Recombiant Pharmaceutical Protein Expression System of Henan, Xinxiang Medical University, Xinxiang, Henan, China.,Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, Henan, China
| | - Wei-Li Zhang
- International Joint Research Laboratory for Recombiant Pharmaceutical Protein Expression System of Henan, Xinxiang Medical University, Xinxiang, Henan, China.,Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, Henan, China
| | - Xiao-Yin Wang
- International Joint Research Laboratory for Recombiant Pharmaceutical Protein Expression System of Henan, Xinxiang Medical University, Xinxiang, Henan, China.,Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, Henan, China
| | - Jun-He Zhang
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, Henan, China
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18
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Wang XY, Zhang X, Wang TY, Jia YL, Xu DH, Yi DD. Shortened nuclear matrix attachment regions are sufficient for replication and maintenance of episomes in mammalian cells. Mol Biol Cell 2019; 30:2761-2770. [PMID: 31509492 PMCID: PMC6789156 DOI: 10.1091/mbc.e19-02-0108] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Matrix attachment regions (MARs) can mediate the replication of vector episomes in mammalian cells; however, the molecular mode of action remains unclear. Here, we assessed the characteristics of MARs and the mechanism that mediates episomal vector replication in mammalian cells. Five shortened subfragments of β-interferon MAR fragments were cloned and transferred into CHO cells, and transgene expression levels, presence of the gene, and the episomal maintenance mechanism were determined. Three shortened MAR derivatives (position 781–1320, 1201–1740, and 1621–2201) retained full MAR activity and mediated episomal vector replication. Moreover, the three shortened MARs showed higher transgene expression levels, greater efficiency in colony formation, and more persistent transgene expression compared with those of the original pEPI-1 plasmid, and three functional truncated MARs can bind to SAF-A MAR-binding protein. These results suggest that shortened MARs are sufficient for replication and maintenance of episomes in CHO cells.
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Affiliation(s)
- Xiao-Yin Wang
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang 453003, Henan, China.,International Joint Research Laboratory for Recombiant Pharmaceutical Protein Expression System of Henan, Xinxiang Medical University, Xinxiang 453003, Henan, China
| | - Xi Zhang
- International Joint Research Laboratory for Recombiant Pharmaceutical Protein Expression System of Henan, Xinxiang Medical University, Xinxiang 453003, Henan, China
| | - Tian-Yun Wang
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang 453003, Henan, China.,International Joint Research Laboratory for Recombiant Pharmaceutical Protein Expression System of Henan, Xinxiang Medical University, Xinxiang 453003, Henan, China
| | - Yan-Long Jia
- Pharmacy Collage, Xinxiang Medical University, Xinxiang 453003, Henan, China
| | - Dan-Hua Xu
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang 453003, Henan, China.,International Joint Research Laboratory for Recombiant Pharmaceutical Protein Expression System of Henan, Xinxiang Medical University, Xinxiang 453003, Henan, China
| | - Dan-Dan Yi
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang 453003, Henan, China.,International Joint Research Laboratory for Recombiant Pharmaceutical Protein Expression System of Henan, Xinxiang Medical University, Xinxiang 453003, Henan, China
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19
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Wang XY, Yi DD, Wang TY, Wu YF, Chai YR, Xu DH, Zhao CP, Song C. Enhancing expression level and stability of transgene mediated by episomal vector via buffering DNA methyltransferase in transfected CHO cells. J Cell Biochem 2019; 120:15661-15670. [PMID: 31074065 DOI: 10.1002/jcb.28835] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 02/01/2019] [Accepted: 02/04/2019] [Indexed: 12/17/2022]
Abstract
Nonviral episomal vectors present attractive alternative vehicles for gene therapy applications. Previously, we have established a new type of nonviral episomal vector-mediated by the characteristic motifs of matrix attachment regions (MARs), which is driven by the cytomegalovirus (CMV) promoter. However, the CMV promoter is intrinsically susceptible to silencing, resulting in declined productivity during long-term culture. In this study, Chinese hamster ovary (CHO) cells and DNA methyltransferase-deficient (Dnmt3a-deficient) CHO cells were transfected with plasmid-mediated by MAR, or CHO cells were treated with the DNA methylation inhibitor 5-Aza-2'-deoxycytidine. Flow cytometry, plasmid rescue experiments, fluorescence in-situ hybridization (FISH), and bisulfite sequencing were performed to observe transgene expression, its state of existence, and the CpG methylation level of the CMV promoter. The results indicated that all DNA methylation inhibitor and methyltransferase deficient cells could increase transgene expression levels and stability in the presence or absence of selection pressure after a 60-generation culture. Plasmid rescue assay and FISH analysis showed that the vector still existed episomally after long-time culture. Moreover, a relatively lower CMV promoter methylation level was observed in Dnmt3a-deficient cell lines and CHO cells treated with 5-Aza-2'-deoxycytidine. In addition, Dnmt3a-deficient cells were superior to the DNA methylation inhibitor treatment regarding the transgene expression and long-term stability. Our study provides the first evidence that lower DNA methyltransferase can enhance expression level and stability of transgenes mediated by episomal vectors in transfected CHO cells.
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Affiliation(s)
- Xiao-Yin Wang
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, Henan, China.,International Joint Research Laboratory for Recombiant Pharmaceutical Protein Expression System of Henan, Xinxiang Medical University, Xinxiang, Henan, China
| | - Dan-Dan Yi
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, Henan, China
| | - Tian-Yun Wang
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, Henan, China.,International Joint Research Laboratory for Recombiant Pharmaceutical Protein Expression System of Henan, Xinxiang Medical University, Xinxiang, Henan, China
| | - Yan-Fang Wu
- Department of Pharmacy, Medical College, Henan University of Science and Technology, Luoyang, China
| | - Yu-Rong Chai
- Department of Histology and Embryology, School of Basic Medical Sciences, University of Zhengzhou, Zhengzhou, Henan, China
| | - Dan-Hua Xu
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, Henan, China
| | - Chun-Peng Zhao
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, Henan, China
| | - Chao Song
- International Joint Research Laboratory for Recombiant Pharmaceutical Protein Expression System of Henan, Xinxiang Medical University, Xinxiang, Henan, China
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20
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Wang W, Guo X, Li YM, Wang XY, Yang XJ, Wang YF, Wang TY. Enhanced transgene expression using cis-acting elements combined with the EF1 promoter in a mammalian expression system. Eur J Pharm Sci 2018; 123:539-545. [DOI: 10.1016/j.ejps.2018.08.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 07/12/2018] [Accepted: 08/11/2018] [Indexed: 10/28/2022]
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21
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Vectored gene delivery for lifetime animal contraception: Overview and hurdles to implementation. Theriogenology 2018; 112:63-74. [DOI: 10.1016/j.theriogenology.2017.11.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2017] [Revised: 10/25/2017] [Accepted: 11/02/2017] [Indexed: 12/24/2022]
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22
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Human rhinovirus internal ribosome entry site element enhances transgene expression in transfected CHO-S cells. Sci Rep 2018; 8:6661. [PMID: 29703950 PMCID: PMC5923211 DOI: 10.1038/s41598-018-25049-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 04/13/2018] [Indexed: 01/27/2023] Open
Abstract
Chinese hamster ovary (CHO) cells are mainly used for recombinant protein production. However, the unstable transgene expression and lower transgene copy numbers are the major issues need to be resolved. Here, eleven internal ribosome entry site (IRES) elements from viral and cellular IRES were evaluated for foreign gene expression in CHO-S cells. We constructed eleven fusing plasmids containing different IRES sequences downstream of the enhanced green fluorescent protein (EGFP) gene. EGFP expression was detected by flow cytometry and the transgene copy number was evaluated by quantitative PCR. The erythropoietin (EPO) protein was also used to assess the stronger IRES. The results showed that IRES from human rhinovirus (HRV) exhibited the highest EGFP expression level under transient and stable transfections. The EGFP expression level of vector with IRES from HRV was related to the gene copy number in stably transfected CHO-S cells. Moreover, IRES from HRV induced higher expression level of EPO compared with one mutant IRES from EMCV in transfected cells. In conclusion, IRES from HRV can function as a strong IRES element for stable expression in CHO-S cells, which could potentially guide more effective foreign gene expression in CHO-S cells.
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23
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Romanova N, Noll T. Engineered and Natural Promoters and Chromatin-Modifying Elements for Recombinant Protein Expression in CHO Cells. Biotechnol J 2017; 13:e1700232. [DOI: 10.1002/biot.201700232] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 11/07/2017] [Indexed: 12/13/2022]
Affiliation(s)
- Nadiya Romanova
- Cell Culture Technology; Faculty of Technology; Bielefeld University; Germany
| | - Thomas Noll
- Cell Culture Technology; Faculty of Technology; Bielefeld University; Germany
- Bielefeld University; Center for Biotechnology (CeBiTec); Germany
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24
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Tian ZW, Xu DH, Wang TY, Wang XY, Xu HY, Zhao CP, Xu GH. Identification of a potent MAR element from the human genome and assessment of its activity in stably transfected CHO cells. J Cell Mol Med 2017; 22:1095-1102. [PMID: 29077269 PMCID: PMC5783848 DOI: 10.1111/jcmm.13361] [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: 06/07/2017] [Accepted: 07/25/2017] [Indexed: 01/23/2023] Open
Abstract
Low-level and unstable transgene expression are common issues using the CHO cell expression system. Matrix attachment regions (MARs) enhance transgene expression levels, but additional research is needed to improve their function and to determine their mechanism of action. MAR-6 from CHO chromosomes actively mediates high and consistent gene expression. In this study, we compared the effects of two new MARs and MAR-6 on transgene expression in recombinant CHO cells and found one potent MAR element that can significantly increase transgene expression. Two MARs, including the human CSP-B MAR element and DHFR intron MAR element from CHO cells, were cloned and inserted downstream of the poly(A) site in a eukaryotic vector. The constructs were transfected into CHO cells, and the expression levels and stability of eGFP were detected by flow cytometry. The three MAR sequences can be ranked in terms of overall eGFP expression, in decreasing order, as follows: human CSP-B, DHFR intron MAR element and MAR-6. Additionally, as expected, the three MAR-containing vectors showed higher transfection efficiencies and transient transgene expression in comparison with those of the non-MAR-containing vector. Bioinformatics analysis indicated that the NFAT and VIBP elements within MAR sequences may contribute to the enhancement of eGFP expression. In conclusion, the human CSP-B MAR element can improve transgene expression and its effects may be related to the NFAT and VIBP elements.
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Affiliation(s)
- Zheng-Wei Tian
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, Henan, China
| | - Dan-Hua Xu
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, Henan, China
| | - Tian-Yun Wang
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, Henan, China
| | - Xiao-Yin Wang
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, Henan, China
| | - Hong-Yan Xu
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, Henan, China
| | - Chun-Peng Zhao
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, Henan, China
| | - Guang-Hua Xu
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, Henan, China
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25
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Impact of different promoters, promoter mutation, and an enhancer on recombinant protein expression in CHO cells. Sci Rep 2017; 7:10416. [PMID: 28874794 PMCID: PMC5585415 DOI: 10.1038/s41598-017-10966-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 08/17/2017] [Indexed: 11/09/2022] Open
Abstract
In the present study, six commonly used promoters, including cytomegalovirus major immediate-early (CMV), the CMV enhancer fused to the chicken beta-actin promoter (CAG), human elongation factor-1α (HEF-1α), mouse cytomegalovirus (mouse CMV), Chinese hamster elongation factor-1α (CHEF-1α), and phosphoglycerate kinase (PGK), a CMV promoter mutant and a CAG enhancer, were evaluated to determine their effects on transgene expression and stability in transfected CHO cells. The promoters and enhancer were cloned or synthesized, and mutation at C-404 in the CMV promoter was generated; then all elements were transfected into CHO cells. Stably transfected CHO cells were identified via screening under the selection pressure of G418. Flow cytometry, qPCR, and qRT-PCR were used to explore eGFP expression levels, gene copy number, and mRNA expression levels, respectively. Furthermore, the erythropoietin (EPO) gene was used to test the selected strong promoter. Of the six promoters, the CHEF-1α promoter yielded the highest transgene expression levels, whereas the CMV promoter maintained transgene expression more stably during long-term culture of cells. We conclude that CHEF-1α promoter conferred higher level of EPO expression in CHO cells, but the CMV promoter with its high levels of stability performs best in this vector system.
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26
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Li Q, Wang W, Guo X, Jia YL, Wang YF, Wang TY. A short synthetic chimeric sequence harboring matrix attachment region/PSAR2 increases transgene expression in Chinese hamster ovary cells. Biosci Biotechnol Biochem 2017; 81:1755-1761. [DOI: 10.1080/09168451.2017.1350563] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Abstract
A chimeric DNA fragment containing an interferon-beta matrix attachment region (MAR) and an immunoglobulin MAR (PSAR2) was synthesized. PSAR2 was cloned into the upstream or downstream region of an enhanced green fluorescent protein (eGFP) expression cassette in a eukaryotic vector, which was then transfected into CHO cells. The results showed that PSAR2 did not effectively increase transgene expression when it was cloned into the upstream region of the eGFP expression cassette. However, when inserted downstream of the eGFP expression cassette, PSAR2-enhanced transient transgene expression and significantly increased the numbers of stably transfected cells compared with the control vector. Additionally, PSAR2 significantly increased eGFP copy numbers as compared with the control vector. PSAR2 could significantly enhance transgene expression in CHO cells according to the position in the vector and increased transgene copy numbers. We found a short chimeric sequence harboring two MARs effectively increased transgene expression in CHO cells.
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Affiliation(s)
- Qin Li
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, China
| | - Wen Wang
- Pharmacy College, Xinxiang Medical University, Xinxiang, China
| | - Xiao Guo
- Pharmacy College, Xinxiang Medical University, Xinxiang, China
| | - Yan-Long Jia
- Pharmacy College, Xinxiang Medical University, Xinxiang, China
| | - Yan-Fang Wang
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, China
| | - Tian-Yun Wang
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, China
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27
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Wang X, Xu Z, Tian Z, Zhang X, Xu D, Li Q, Zhang J, Wang T. The EF-1α promoter maintains high-level transgene expression from episomal vectors in transfected CHO-K1 cells. J Cell Mol Med 2017; 21:3044-3054. [PMID: 28557288 PMCID: PMC5661254 DOI: 10.1111/jcmm.13216] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2017] [Accepted: 04/01/2017] [Indexed: 02/03/2023] Open
Abstract
In our previous study, we demonstrated that episomal vectors based on the characteristic sequence of matrix attachment regions (MARs) and containing the cytomegalovirus (CMV) promoter allow transgenes to be maintained episomally in Chinese hamster ovary (CHO) cells. However, the transgene expression was unstable and the number of copies was low. In this study, we focused on enhancers, various promoters and promoter variants that could improve the transgene expression stability, expression magnitude (level) and the copy number of a MAR‐based episomal vector in CHO‐K1 cells. In comparison with the CMV promoter, the eukaryotic translation elongation factor 1 α (EF‐1α, gene symbol EEF1A1) promoter increased the transfection efficiency, the transgene expression, the proportion of expression‐positive clones and the copy number of the episomal vector in long‐term culture. By contrast, no significant positive effects were observed with an enhancer, CMV promoter variants or CAG promoter in the episomal vector in long‐term culture. Moreover, the high‐expression clones harbouring the EF‐1α promoter tended to be more stable in long‐term culture, even in the absence of selection pressure. According to these findings, we concluded that the EF‐1α promoter is a potent regulatory sequence for episomal vectors because it maintains high transgene expression, transgene stability and copy number. These results provide valuable information on improvement of transgene stability and the copy number of episomal vectors.
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Affiliation(s)
- Xiaoyin Wang
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, Henan, China.,Henan Collaborative Innovation Center of Molecular Diagnosis and Laboratory Medicine, Xinxiang, Henan, China
| | - Zhongjie Xu
- Life Science and Technology, Xinxiang Medical University, Xinxiang, Henan, China
| | - Zhengwei Tian
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, Henan, China
| | - Xi Zhang
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, Henan, China
| | - Danhua Xu
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, Henan, China
| | - Qin Li
- Test Laboratory, Xinxiang Medical University, Xinxiang, Henan, China
| | - Junhe Zhang
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, Henan, China
| | - Tianyun Wang
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, Henan, China
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28
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Zhao CP, Guo X, Chen SJ, Li CZ, Yang Y, Zhang JH, Chen SN, Jia YL, Wang TY. Matrix attachment region combinations increase transgene expression in transfected Chinese hamster ovary cells. Sci Rep 2017; 7:42805. [PMID: 28216629 PMCID: PMC5316954 DOI: 10.1038/srep42805] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Accepted: 01/16/2017] [Indexed: 11/09/2022] Open
Abstract
Matrix attachment regions (MARs) are cis-acting DNA elements that can increase transgene expression levels in a CHO cell expression system. To investigate the effects of MAR combinations on transgene expression and the underlying regulatory mechanisms, we generated constructs in which the enhanced green fluorescent protein (eGFP) gene flanked by different combinations of human β-interferon and β-globin MAR (iMAR and gMAR, respectively), which was driven by the cytomegalovirus (CMV) or simian virus (SV) 40 promoter. These were transfected into CHO-K1 cells, which were screened with geneticin; eGFP expression was detected by flow cytometry. The presence of MAR elements increased transfection efficiency and transient and stably expression of eGFP expression under both promoters; the level was higher when the two MARs differed (i.e., iMAR and gMAR) under the CMV but not the SV40 promoter. For the latter, two gMARs showed the highest activity. We also found that MARs increased the ratio of stably transfected positive colonies. These results indicate that combining the CMV promoter with two different MAR elements or the SV40 promoter with two gMARs is effective for inducing high expression level and stability of transgenes.
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Affiliation(s)
- Chun-Peng Zhao
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Henan 453003, China
| | - Xiao Guo
- Pharmacy College, Xinxiang Medical University, Xinxiang 453003, Henan, China
| | - Si-Jia Chen
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Henan 453003, China
| | - Chang-Zheng Li
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Henan 453003, China
| | - Yun Yang
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Henan 453003, China
| | - Jun-He Zhang
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Henan 453003, China
| | - Shao-Nan Chen
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Henan 453003, China
| | - Yan-Long Jia
- Pharmacy College, Xinxiang Medical University, Xinxiang 453003, Henan, China
| | - Tian-Yun Wang
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Henan 453003, China
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