1
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Zhang C, Liu D. Transcription Factor Binding Site in Promoter Determines the Pattern of Plasmid-Based Transgene Expression In Vivo. Pharmaceutics 2024; 16:544. [PMID: 38675205 PMCID: PMC11055139 DOI: 10.3390/pharmaceutics16040544] [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: 02/08/2024] [Revised: 04/11/2024] [Accepted: 04/12/2024] [Indexed: 04/28/2024] Open
Abstract
Understanding the regulation of transgene expression is critical for the success of plasmid-based gene therapy and vaccine development. In this study, we used two sets of plasmid vectors containing secreted embryonic alkaline phosphatase or the mouse IL-10 gene as a reporter and investigated the role of promoter elements in regulating transgene expression in vivo. We demonstrated in mice that hydrodynamic transfer of plasmids with the CMV promoter resulted in a high level of reporter gene expression that declined rapidly over time. In contrast, when plasmids with albumin promoters were used, a lower but sustained gene expression pattern was observed. We also found that plasmids containing a shorter CMV promoter sequence with fewer transcription factor binding sites showed a decrease in the peak level of gene expression without changing the overall pattern of reporter gene expression. The replacement of regulatory elements in the CMV promoter with a single regulatory element of the albumin promoter changed the pattern of transient gene expression seen in the CMV promoter to a pattern of sustained gene expression identical to that of a full albumin promoter. ChIP analyses demonstrated an elevated binding of acetylated histones and TATA box-binding protein to the promoter carrying regulatory elements of the albumin promoter. These results suggest that the strength of a promoter is determined by the number of appropriate transcription factor binding sites, while gene expression persistence is determined by the presence of regulatory elements capable of recruiting epigenetic modifying complexes that make the promoter accessible for transcription. This study provides important insights into the mechanisms underlying gene expression regulation in vivo, which can be used to improve plasmid-based gene therapy and vaccine development.
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Affiliation(s)
| | - Dexi Liu
- Department of Pharmaceutical and Biomedical Sciences, University of Georgia College of Pharmacy, Athens, GA 30602, USA;
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2
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Fallahee I, Hawiger D. Episomal Vectors for Stable Production of Recombinant Proteins and Engineered Antibodies. Antibodies (Basel) 2024; 13:18. [PMID: 38534208 PMCID: PMC10967652 DOI: 10.3390/antib13010018] [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: 02/01/2024] [Revised: 02/27/2024] [Accepted: 03/04/2024] [Indexed: 03/28/2024] Open
Abstract
There is tremendous interest in the production of recombinant proteins, particularly bispecific antibodies and antibody-drug conjugates for research and therapeutic use. Here, we demonstrate a highly versatile plasmid system that allows the rapid generation of stable Expi293 cell pools by episomal retention of transfected DNA. By linking protein expression to puromycin resistance through an attenuated internal ribosome entry site, we achieve stable cell pools producing proteins of interest. In addition, split intein-split puromycin-mediated selection of two separate protein expression cassettes allows the stable production of bispecific antibody-like molecules or antibodies with distinct C-terminal heavy chain modifications, such as an antigen on one chain and a sortase tag on the other chain. We also use this novel expression system to generate stable Expi293 cell pools that secrete sortase A Δ59 variant Srt4M. Using these reagents, we prepared a site-specific drug-to-antibody ratio of 1 antibody-siRNA conjugate. We anticipate the simple, robust, and rapid stable protein expression systems described here being useful for a wide variety of applications.
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Affiliation(s)
| | - Daniel Hawiger
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, St. Louis, MO 63104, USA
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3
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Fallahee I, Hawiger D. EPISOMAL VECTORS FOR STABLE PRODUCTION OF RECOMBINANT PROTEINS AND ENGINEERED ANTIBODIES. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.03.574076. [PMID: 38260603 PMCID: PMC10802304 DOI: 10.1101/2024.01.03.574076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
There is tremendous interest in the production of recombinant proteins, particularly bispecific antibodies and antibody-drug conjugates for research and therapeutic use. Here, we demonstrate a highly versatile plasmid system that allows rapid generation of stable Expi293 cell pools by episomal retention of transfected DNA. By linking protein expression to puromycin resistance though an attenuated internal ribosome entry site, we achieve stable cell pools producing proteins of interest. In addition, split intein-split puromycin-mediated selection of two separate protein expression cassettes allows the stable production of bispecific antibody-like molecules or antibodies with distinct C-terminal heavy chain modifications, such as an antigen on one chain and a sortase tag on the other chain. We also use this novel expression system to generate stable Expi293 cell pools that secrete sortase A Δ59 variant Srt4M. Using these reagents, we prepared a site-specific drug-to-antibody ratio of 1 antibody-siRNA conjugate. We anticipate the simple, robust, and rapid stable protein expression systems described here being useful for a wide variety of applications.
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4
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Guo L, Yang G. Pioneering DNA assembling techniques and their applications in eukaryotic microalgae. Biotechnol Adv 2024; 70:108301. [PMID: 38101551 DOI: 10.1016/j.biotechadv.2023.108301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 11/12/2023] [Accepted: 12/08/2023] [Indexed: 12/17/2023]
Abstract
Assembling DNA fragments is a fundamental manipulation of cloning microalgal genes and carrying out microalgal synthetic biological studies. From the earliest DNA recombination to current trait and metabolic pathway engineering, we are always accompanied by homology-based DNA assembling. The improvement and modification of pioneering DNA assembling techniques and the combinational applications of the available assembling techniques have diversified and complicated the literature environment and aggravated our identification of the core and pioneering methodologies. Identifying the core assembling methodologies and using them appropriately and flourishing them even are important for researchers. A group of microalgae have been evolving as the models for both industrial applications and biological studies. DNA assembling requires researchers to know the methods available and their improvements and evolvements. In this review, we summarized the pioneering (core; leading) DNA assembling techniques developed previously, extended these techniques to their modifications, improvements and their combinations, and highlighted their applications in eukaryotic microalgae. We predicted that the gene(s) will be assembled into a functional cluster (e.g., those involving in a metabolic pathway, and stacked on normal microalgal chromosomes, their artificial episomes and looming artificial chromosomes. It should be particularly pointed out that the techniques mentioned in this review are classified according to the strategy used to assemble the final construct.
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Affiliation(s)
- Li Guo
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, PR China
| | - Guanpin Yang
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, PR China; Institutes of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, PR China; MoE Laboratory of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, PR China; Key Laboratory of Marine Genetics and Breeding of Ministry of Education, Ocean University of China, Qingdao 266003, China.
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5
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Lazaris VM, Simantirakis E, Stavrou EF, Verras M, Sgourou A, Keramida MK, Vassilopoulos G, Athanassiadou A. Non-Viral Episomal Vector Mediates Efficient Gene Transfer of the β-Globin Gene into K562 and Human Haematopoietic Progenitor Cells. Genes (Basel) 2023; 14:1774. [PMID: 37761914 PMCID: PMC10530965 DOI: 10.3390/genes14091774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 07/13/2023] [Accepted: 09/04/2023] [Indexed: 09/29/2023] Open
Abstract
β-Thalassemia is a subgroup of inherited blood disorders associated with mild to severe anemia with few and limited conventional therapy options. Lately, lentiviral vector-based gene therapy has been successfully applied for disease treatment. However, the current development of non-viral episomal vectors (EV), non-integrating and non-coding for viral proteins, may be helpful in generating valid alternatives to viral vectors. We constructed a non-viral, episomal vector pEPβ-globin for the physiological β-globin gene based on two human chromosomal elements: the scaffold or matrix attachment region (S/MAR), allowing for long nuclear retention and non-integration and the β-globin replication initiation region (IR), allowing for enhancement of replication and establishment. After nucleofections into K562 cells with a transfection efficiency of 24.62 ± 7.7%, the vector induces stable transfection and is detected in long-term cultures as a non-integrating, circular episome expressing the β-globin gene efficiently. Transfections into CD34+ cells demonstrate an average efficiency of 15.57 ± 11.64%. In the colony-forming cell assay, fluorescent colonies are 92.21%, which is comparable to those transfected with vector pEP-IR at 92.68%. Additionally, fluorescent colonies produce β-globin mRNA at a physiologically 3-fold higher level than the corresponding non-transfected cells. Vector pEPβ-globin provides the basis for the development of therapeutic EV for gene therapy of β-thalassemias.
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Affiliation(s)
- Vassileios M. Lazaris
- Department of General Biology, Medical School, University of Patras, 26504 Patras, Greece; (V.M.L.); (E.F.S.); (M.V.)
| | - Emmanouil Simantirakis
- Centre of Basic Research, Biomedical Research Foundation of the Academy of Athens (BRFAA), 11527 Athens, Greece; (E.S.); (G.V.)
| | - Eleana F. Stavrou
- Department of General Biology, Medical School, University of Patras, 26504 Patras, Greece; (V.M.L.); (E.F.S.); (M.V.)
| | - Meletios Verras
- Department of General Biology, Medical School, University of Patras, 26504 Patras, Greece; (V.M.L.); (E.F.S.); (M.V.)
| | - Argyro Sgourou
- Biology Laboratory, School of Science and Technology, Hellenic Open University, 26335 Patras, Greece;
| | - Maria K. Keramida
- IVF and Andrology Labs, IVF Unit, General University Hospital of Patras, 26504 Patras, Greece;
| | - George Vassilopoulos
- Centre of Basic Research, Biomedical Research Foundation of the Academy of Athens (BRFAA), 11527 Athens, Greece; (E.S.); (G.V.)
| | - Aglaia Athanassiadou
- Department of General Biology, Medical School, University of Patras, 26504 Patras, Greece; (V.M.L.); (E.F.S.); (M.V.)
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6
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Giandomenico SL, Schuman EM. Genetic manipulation and targeted protein degradation in mammalian systems: practical considerations, tips and tricks for discovery research. FEBS Open Bio 2023. [PMID: 36815235 DOI: 10.1002/2211-5463.13581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 01/13/2023] [Accepted: 02/21/2023] [Indexed: 02/24/2023] Open
Abstract
Gaining a mechanistic understanding of the molecular pathways underpinning cellular and organismal physiology invariably relies on the perturbation of an experimental system to infer causality. This can be achieved either by genetic manipulation or by pharmacological treatment. Generally, the former approach is applicable to a wider range of targets, is more precise, and can address more nuanced functional aspects. Despite such apparent advantages, genetic manipulation (i.e., knock-down, knock-out, mutation, and tagging) in mammalian systems can be challenging due to problems with delivery, low rates of homologous recombination, and epigenetic silencing. The advent of CRISPR-Cas9 in combination with the development of robust differentiation protocols that can efficiently generate a variety of different cell types in vitro has accelerated our ability to probe gene function in a more physiological setting. Often, the main obstacle in this path of enquiry is to achieve the desired genetic modification. In this short review, we will focus on gene perturbation in mammalian cells and how editing and differentiation of pluripotent stem cells can complement more traditional approaches. Additionally, we introduce novel targeted protein degradation approaches as an alternative to DNA/RNA-based manipulation. Our aim is to present a broad overview of recent approaches and in vitro systems to study mammalian cell biology. Due to space limitations, we limit ourselves to providing the inexperienced reader with a conceptual framework on how to use these tools, and for more in-depth information, we will provide specific references throughout.
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Affiliation(s)
| | - Erin M Schuman
- Max Planck Institute for Brain Research, Frankfurt am Main, Germany
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7
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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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8
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Tsai HC, Pietrobon V, Peng M, Wang S, Zhao L, Marincola FM, Cai Q. Current strategies employed in the manipulation of gene expression for clinical purposes. J Transl Med 2022; 20:535. [PMID: 36401279 PMCID: PMC9673226 DOI: 10.1186/s12967-022-03747-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 09/29/2022] [Indexed: 11/19/2022] Open
Abstract
Abnormal gene expression level or expression of genes containing deleterious mutations are two of the main determinants which lead to genetic disease. To obtain a therapeutic effect and thus to cure genetic diseases, it is crucial to regulate the host's gene expression and restore it to physiological conditions. With this purpose, several molecular tools have been developed and are currently tested in clinical trials. Genome editing nucleases are a class of molecular tools routinely used in laboratories to rewire host's gene expression. Genome editing nucleases include different categories of enzymes: meganucleses (MNs), zinc finger nucleases (ZFNs), clustered regularly interspaced short palindromic repeats (CRISPR)- CRISPR associated protein (Cas) and transcription activator-like effector nuclease (TALENs). Transposable elements are also a category of molecular tools which includes different members, for example Sleeping Beauty (SB), PiggyBac (PB), Tol2 and TcBuster. Transposons have been used for genetic studies and can serve as gene delivery tools. Molecular tools to rewire host's gene expression also include episomes, which are divided into different categories depending on their molecular structure. Finally, RNA interference is commonly used to regulate gene expression through the administration of small interfering RNA (siRNA), short hairpin RNA (shRNA) and bi-functional shRNA molecules. In this review, we will describe the different molecular tools that can be used to regulate gene expression and discuss their potential for clinical applications. These molecular tools are delivered into the host's cells in the form of DNA, RNA or protein using vectors that can be grouped into physical or biochemical categories. In this review we will also illustrate the different types of payloads that can be used, and we will discuss recent developments in viral and non-viral vector technology.
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Affiliation(s)
| | | | - Maoyu Peng
- Kite Pharma Inc, Santa Monica, CA, 90404, USA
| | - Suning Wang
- Kite Pharma Inc, Santa Monica, CA, 90404, USA
| | - Lihong Zhao
- Kite Pharma Inc, Santa Monica, CA, 90404, USA
| | | | - Qi Cai
- Kite Pharma Inc, Santa Monica, CA, 90404, USA.
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9
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Episomes and Transposases-Utilities to Maintain Transgene Expression from Nonviral Vectors. Genes (Basel) 2022; 13:genes13101872. [PMID: 36292757 PMCID: PMC9601623 DOI: 10.3390/genes13101872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 10/07/2022] [Accepted: 10/14/2022] [Indexed: 11/04/2022] Open
Abstract
The efficient delivery and stable transgene expression are critical for applications in gene therapy. While carefully selected and engineered viral vectors allowed for remarkable clinical successes, they still bear significant safety risks. Thus, nonviral vectors are a sound alternative and avoid genotoxicity and adverse immunological reactions. Nonviral vector systems have been extensively studied and refined during the last decades. Emerging knowledge of the epigenetic regulation of replication and spatial chromatin organisation, as well as new technologies, such as Crispr/Cas, were employed to enhance the performance of different nonviral vector systems. Thus, nonviral vectors are in focus and hold some promising perspectives for future applications in gene therapy. This review addresses three prominent nonviral vector systems: the Sleeping Beauty transposase, S/MAR-based episomes, and viral plasmid replicon-based EBV vectors. Exemplarily, we review different utilities, modifications, and new concepts that were pursued to overcome limitations regarding stable transgene expression and mitotic stability. New insights into the nuclear localisation of nonviral vector molecules and the potential consequences thereof are highlighted. Finally, we discuss the remaining limitations and provide an outlook on possible future developments in nonviral vector technology.
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10
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LRF Promotes Indirectly Advantageous Chromatin Conformation via BGLT3-lncRNA Expression and Switch from Fetal to Adult Hemoglobin. Int J Mol Sci 2022; 23:ijms23137025. [PMID: 35806029 PMCID: PMC9266405 DOI: 10.3390/ijms23137025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 06/21/2022] [Accepted: 06/22/2022] [Indexed: 02/01/2023] Open
Abstract
The hemoglobin switch from fetal (HbF) to adult (HbA) has been studied intensively as an essential model for gene expression regulation, but also as a beneficial therapeutic approach for β-hemoglobinopathies, towards the objective of reactivating HbF. The transcription factor LRF (Leukemia/lymphoma-related), encoded from the ZBTB7A gene has been implicated in fetal hemoglobin silencing, though has a wide range of functions that have not been fully clarified. We thus established the LRF/ZBTB7A-overexpressing and ZBTB7A-knockdown K562 (human erythroleukemia cell line) clones to assess fetal vs. adult hemoglobin production pre- and post-induction. Transgenic K562 clones were further developed and studied under the influence of epigenetic chromatin regulators, such as DNA methyl transferase 3 (DNMT3) and Histone Deacetylase 1 (HDAC1), to evaluate LRF’s potential disturbance upon the aberrant epigenetic background and provide valuable information of the preferable epigenetic frame, in which LRF unfolds its action on the β-type globin’s expression. The ChIP-seq analysis demonstrated that LRF binds to γ-globin genes (HBG2/1) and apparently associates BCL11A for their silencing, but also during erythropoiesis induction, LRF binds the BGLT3 gene, promoting BGLT3-lncRNA production through the γ-δ intergenic region of β-type globin’s locus, triggering the transcriptional events from γ- to β-globin switch. Our findings are supported by an up-to-date looping model, which highlights chromatin alterations during erythropoiesis at late stages of gestation, to establish an “open” chromatin conformation across the γ-δ intergenic region and accomplish β-globin expression and hemoglobin switch.
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11
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Roig-Merino A, Urban M, Bozza M, Peterson JD, Bullen L, Büchler-Schäff M, Stäble S, van der Hoeven F, Müller-Decker K, McKay TR, Milsom MD, Harbottle RP. An episomal DNA vector platform for the persistent genetic modification of pluripotent stem cells and their differentiated progeny. Stem Cell Reports 2021; 17:143-158. [PMID: 34942088 PMCID: PMC8758943 DOI: 10.1016/j.stemcr.2021.11.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 11/23/2021] [Accepted: 11/24/2021] [Indexed: 11/14/2022] Open
Abstract
The genetic modification of stem cells (SCs) is typically achieved using integrating vectors, whose potential integrative genotoxicity and propensity for epigenetic silencing during differentiation limit their application. The genetic modification of cells should provide sustainable levels of transgene expression, without compromising the viability of a cell or its progeny. We developed nonviral, nonintegrating, and autonomously replicating minimally sized DNA nanovectors to persistently genetically modify SCs and their differentiated progeny without causing any molecular or genetic damage. These DNA vectors are capable of efficiently modifying murine and human pluripotent SCs with minimal impact and without differentiation-mediated transgene silencing or vector loss. We demonstrate that these vectors remain episomal and provide robust and sustained transgene expression during self-renewal and targeted differentiation of SCs both in vitro and in vivo through embryogenesis and differentiation into adult tissues, without damaging their phenotypic characteristics. Nanovectors are used to engineer SCs efficiently, safely, and persistently Isogenic SC lines retain their capacity for self-renewal and pluripotency Nanovectors survive reprogramming and differentiation without loss or silencing Nanovectors are a universal genetic tool for the modification of any cell
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Affiliation(s)
- Alicia Roig-Merino
- DNA Vectors, German Cancer Research Center (DKFZ), Heidelberg 69120, Germany
| | - Manuela Urban
- DNA Vectors, German Cancer Research Center (DKFZ), Heidelberg 69120, Germany
| | - Matthias Bozza
- DNA Vectors, German Cancer Research Center (DKFZ), Heidelberg 69120, Germany
| | - Julia D Peterson
- DNA Vectors, German Cancer Research Center (DKFZ), Heidelberg 69120, Germany
| | - Louise Bullen
- Stem Cell Biology, Manchester Metropolitan University (MMU), Manchester M1 5GD, UK
| | - Marleen Büchler-Schäff
- Heidelberg Institute for Stem Cell Technology and Experimental Medicine (Hi-STEM), Heidelberg 69120, Germany; Division of Experimental Hematology, DKFZ, Heidelberg 69120, Germany
| | - Sina Stäble
- Heidelberg Institute for Stem Cell Technology and Experimental Medicine (Hi-STEM), Heidelberg 69120, Germany; Translational Cancer Epigenomics, Division of Translational Medical Oncology, DKFZ, Heidelberg 69120, Germany
| | | | | | - Tristan R McKay
- Stem Cell Biology, Manchester Metropolitan University (MMU), Manchester M1 5GD, UK
| | - Michael D Milsom
- Heidelberg Institute for Stem Cell Technology and Experimental Medicine (Hi-STEM), Heidelberg 69120, Germany; Division of Experimental Hematology, DKFZ, Heidelberg 69120, Germany
| | - Richard P Harbottle
- DNA Vectors, German Cancer Research Center (DKFZ), Heidelberg 69120, Germany.
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12
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Li HM, Ghildyal R, Hu M, Tran KC, Starrs LM, Mills J, Teng MN, Jans DA. Respiratory Syncytial Virus Matrix Protein-Chromatin Association Is Key to Transcriptional Inhibition in Infected Cells. Cells 2021; 10:2786. [PMID: 34685766 PMCID: PMC8534903 DOI: 10.3390/cells10102786] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 09/23/2021] [Accepted: 10/06/2021] [Indexed: 01/07/2023] Open
Abstract
The morbidity and mortality caused by the globally prevalent human respiratory pathogen respiratory syncytial virus (RSV) approaches that world-wide of influenza. We previously demonstrated that the RSV matrix (M) protein shuttles, in signal-dependent fashion, between host cell nucleus and cytoplasm, and that this trafficking is central to RSV replication and assembly. Here we analyze in detail the nuclear role of M for the first time using a range of novel approaches, including quantitative analysis of de novo cell transcription in situ in the presence or absence of RSV infection or M ectopic expression, as well as in situ DNA binding. We show that M, dependent on amino acids 110-183, inhibits host cell transcription in RSV-infected cells as well as cells transfected to express M, with a clear correlation between nuclear levels of M and the degree of transcriptional inhibition. Analysis of bacterially expressed M protein and derivatives thereof mutated in key residues within M's RNA binding domain indicates that M can bind to DNA as well as RNA in a cell-free system. Parallel results for point-mutated M derivatives implicate arginine 170 and lysine 172, in contrast to other basic residues such as lysine 121 and 130, as critically important residues for inhibition of transcription and DNA binding both in situ and in vitro. Importantly, recombinant RSV carrying arginine 170/lysine 172 mutations shows attenuated infectivity in cultured cells and in an animal model, concomitant with altered inflammatory responses. These findings define an RSV M-chromatin interface critical for host transcriptional inhibition in infection, with important implications for anti-RSV therapeutic development.
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Affiliation(s)
- Hong-Mei Li
- Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Melbourne, VIC 3800, Australia; (H.-M.L.); (R.G.); (M.H.)
| | - Reena Ghildyal
- Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Melbourne, VIC 3800, Australia; (H.-M.L.); (R.G.); (M.H.)
- Centre for Research in Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Canberra, ACT 2617, Australia;
| | - Mengjie Hu
- Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Melbourne, VIC 3800, Australia; (H.-M.L.); (R.G.); (M.H.)
| | - Kim C. Tran
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA; (K.C.T.); (M.N.T.)
| | - Lora M. Starrs
- Centre for Research in Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Canberra, ACT 2617, Australia;
| | - John Mills
- Department of Infectious Diseases, School of Biomedical Sciences, Monash University and the Burnet Institute, Melbourne, VIC 3004, Australia;
| | - Michael N. Teng
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA; (K.C.T.); (M.N.T.)
| | - David A. Jans
- Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Melbourne, VIC 3800, Australia; (H.-M.L.); (R.G.); (M.H.)
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13
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Mulia GE, Picanço-Castro V, Stavrou EF, Athanassiadou A, Figueiredo ML. Advances in the Development and the Applications of Non-viral, Episomal Vectors for Gene Therapy. Hum Gene Ther 2021; 32:1076-1095. [PMID: 34348480 PMCID: PMC8819515 DOI: 10.1089/hum.2020.310] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Nonviral and nonintegrating episomal vectors are reemerging as a valid, alternative technology to integrating viral vectors for gene therapy, due to their more favorable safety profile, significantly lower risk for insertional mutagenesis, and a lesser potential for innate immune reactions, in addition to their low production cost. Over the past few years, attempts have been made to generate highly functional nonviral vectors that display long-term maintenance within cells and promote more sustained gene expression relative to conventional plasmids. Extensive research into the parameters that stabilize the episomal DNA within dividing and nondividing cells has shed light into the genetic and epigenetic mechanisms that govern replication and transcription of episomal DNA within a mammalian nucleus in long-term cell culture. Episomal vectors based on scaffold/matrix attachment regions (S/MARs) do not integrate into the genomic DNA and address the serious problem of plasmid loss during mitosis by providing mitotic stability to established plasmids, which results in long-term transfection and transgene expression. The inclusion, in such vectors, of an origin of replication—initiation region—from the human genome has greatly enhanced their performance in primary cell culture. A number of vectors that function as episomes have arisen, which are either devoid or depleted of harmful CpG sequences and bacterial genes, and their effectiveness, as well as that of nonintegrating viral episomes, is enhanced when combined with S/MAR elements. As a result of these advances, an “S/MAR technology” has emerged for the production of efficient episomal vectors. Significant research continues in this field and innovations, in combination with promising systems based on nanoparticles and potentially combined with physical delivery methods, will enable the generation of optimized systems with scale-up and clinical application suitability utilizing episomal vectors.
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Affiliation(s)
- Grace E Mulia
- Purdue University, Basic Medical Sciences, West Lafayette, Indiana, United States;
| | - Virginia Picanço-Castro
- University of Sao Paulo Faculty of Medicine of Ribeirao Preto, 54539, Center for Cell-based Therapy, Ribeirao Preto, São Paulo, Brazil;
| | - Eleana F Stavrou
- University of Patras, Department of General Biology, Patras, Greece;
| | - Aglaia- Athanassiadou
- University of Patras Medical School, General Biology, Asklepiou str, University Campus, Rion Patras, Greece, 26504;
| | - Marxa L Figueiredo
- Purdue University, Basic Medical Sciences, 625 Harrison St., LYNN 2177, West Lafayette, Indiana, United States, 47907;
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14
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Wong YC, Osahor A, Al-Ajli FOM, Narayanan K. Large BACs transfect more efficiently in circular topology. Anal Biochem 2021; 630:114324. [PMID: 34363787 DOI: 10.1016/j.ab.2021.114324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 07/30/2021] [Accepted: 08/01/2021] [Indexed: 10/20/2022]
Abstract
The effect of DNA topology on transfection efficiency of mammalian cells has been widely tested on plasmids smaller than 10 kb, but little is known for larger DNA vectors carrying intact genomic DNA containing introns, exons, and regulatory regions. Here, we demonstrate that circular BACs transfect more efficiently than covalently closed linear BACs. We found up to 3.1- and 8.9- fold higher eGFP expression from circular 11 kb and 100 kb BACs, respectively, compared to linear BACs. These findings provide insights for improved vector development for gene delivery and expression studies of large intact transgenes in mammalian cells.
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Affiliation(s)
- Yin Cheng Wong
- School of Science, Monash University Malaysia, Bandar Sunway, Malaysia
| | - Andrew Osahor
- School of Science, Monash University Malaysia, Bandar Sunway, Malaysia
| | | | - Kumaran Narayanan
- School of Science, Monash University Malaysia, Bandar Sunway, Malaysia.
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15
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16
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Bozza M, De Roia A, Correia MP, Berger A, Tuch A, Schmidt A, Zörnig I, Jäger D, Schmidt P, Harbottle RP. A nonviral, nonintegrating DNA nanovector platform for the safe, rapid, and persistent manufacture of recombinant T cells. SCIENCE ADVANCES 2021; 7:7/16/eabf1333. [PMID: 33853779 PMCID: PMC8046366 DOI: 10.1126/sciadv.abf1333] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 02/25/2021] [Indexed: 05/04/2023]
Abstract
The compelling need to provide adoptive cell therapy (ACT) to an increasing number of oncology patients within a meaningful therapeutic window makes the development of an efficient, fast, versatile, and safe genetic tool for creating recombinant T cells indispensable. In this study, we used nonintegrating minimally sized DNA vectors with an enhanced capability of generating genetically modified cells, and we demonstrate that they can be efficiently used to engineer human T lymphocytes. This vector platform contains no viral components and is capable of replicating extrachromosomally in the nucleus of dividing cells, providing persistent transgene expression in human T cells without affecting their behavior and molecular integrity. We use this technology to provide a manufacturing protocol to quickly generate chimeric antigen receptor (CAR)-T cells at clinical scale in a closed system and demonstrate their enhanced anti-tumor activity in vitro and in vivo in comparison to previously described integrating vectors.
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Affiliation(s)
- Matthias Bozza
- DNA Vector Laboratory, DKFZ Heidelberg, Im Neuenheimer Feld 242, Heidelberg, Germany
| | - Alice De Roia
- DNA Vector Laboratory, DKFZ Heidelberg, Im Neuenheimer Feld 242, Heidelberg, Germany
- Clinical Cooperation Unit Neuroimmunology and Brain Tumor Immunology, DKFZ, Heidelberg, Germany
- Department of Neurology, Medical Faculty Mannheim, MCTN Heidelberg University, Heidelberg, Germany
- Faculty of Bioscience, Heidelberg University, Heidelberg, Germany
| | - Margareta P Correia
- Cancer Biology and Epigenetics Group, Research Center of Portuguese Oncology Institute of Porto, 4200-072 Porto, Portugal
| | - Aileen Berger
- Clinical Cooperation Unit Applied Tumorimmunity, DKFZ Heidelberg, Im Neuenheimer Feld 460, Heidelberg, Germany
- National Center for Tumor Diseases, Medical Oncology, Im Neuenheimer Feld 460, Heidelberg, Germany
| | - Alexandra Tuch
- Clinical Cooperation Unit Applied Tumorimmunity, DKFZ Heidelberg, Im Neuenheimer Feld 460, Heidelberg, Germany
- National Center for Tumor Diseases, Medical Oncology, Im Neuenheimer Feld 460, Heidelberg, Germany
| | | | - Inka Zörnig
- National Center for Tumor Diseases, Medical Oncology, Im Neuenheimer Feld 460, Heidelberg, Germany
- Department of Medical Oncology, University Hospital Heidelberg, Im Neuenheimer Feld 460, Heidelberg, Germany
| | - Dirk Jäger
- Clinical Cooperation Unit Applied Tumorimmunity, DKFZ Heidelberg, Im Neuenheimer Feld 460, Heidelberg, Germany
- National Center for Tumor Diseases, Medical Oncology, Im Neuenheimer Feld 460, Heidelberg, Germany
- Department of Medical Oncology, University Hospital Heidelberg, Im Neuenheimer Feld 460, Heidelberg, Germany
| | - Patrick Schmidt
- National Center for Tumor Diseases, Medical Oncology, Im Neuenheimer Feld 460, Heidelberg, Germany
- Department of Medical Oncology, University Hospital Heidelberg, Im Neuenheimer Feld 460, Heidelberg, Germany
- GMP & T cell Therapy Unit, DKFZ Heidelberg, Im Neuenheimer Feld 280, Heidelberg, Germany
| | - Richard P Harbottle
- DNA Vector Laboratory, DKFZ Heidelberg, Im Neuenheimer Feld 242, Heidelberg, Germany.
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17
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Toualbi L, Toms M, Moosajee M. The Landscape of Non-Viral Gene Augmentation Strategies for Inherited Retinal Diseases. Int J Mol Sci 2021; 22:2318. [PMID: 33652562 PMCID: PMC7956638 DOI: 10.3390/ijms22052318] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 02/23/2021] [Accepted: 02/24/2021] [Indexed: 01/19/2023] Open
Abstract
Inherited retinal diseases (IRDs) are a heterogeneous group of disorders causing progressive loss of vision, affecting approximately one in 1000 people worldwide. Gene augmentation therapy, which typically involves using adeno-associated viral vectors for delivery of healthy gene copies to affected tissues, has shown great promise as a strategy for the treatment of IRDs. However, the use of viruses is associated with several limitations, including harmful immune responses, genome integration, and limited gene carrying capacity. Here, we review the advances in non-viral gene augmentation strategies, such as the use of plasmids with minimal bacterial backbones and scaffold/matrix attachment region (S/MAR) sequences, that have the capability to overcome these weaknesses by accommodating genes of any size and maintaining episomal transgene expression with a lower risk of eliciting an immune response. Low retinal transfection rates remain a limitation, but various strategies, including coupling the DNA with different types of chemical vehicles (nanoparticles) and the use of electrical methods such as iontophoresis and electrotransfection to aid cell entry, have shown promise in preclinical studies. Non-viral gene therapy may offer a safer and effective option for future treatment of IRDs.
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Affiliation(s)
- Lyes Toualbi
- UCL Institute of Ophthalmology, London EC1V 9EL, UK; (L.T.); (M.T.)
- The Francis Crick Institute, London NW1 1AT, UK
| | - Maria Toms
- UCL Institute of Ophthalmology, London EC1V 9EL, UK; (L.T.); (M.T.)
- The Francis Crick Institute, London NW1 1AT, UK
| | - Mariya Moosajee
- UCL Institute of Ophthalmology, London EC1V 9EL, UK; (L.T.); (M.T.)
- The Francis Crick Institute, London NW1 1AT, UK
- Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK
- Great Ormond Street Hospital for Children NHS Found Trust, London WC1N 3JH, UK
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18
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Szeltner Z, Póti Á, Harami GM, Kovács M, Szüts D. Evaluation and modulation of DNA lesion bypass in an SV40 large T antigen-based in vitro replication system. FEBS Open Bio 2021; 11:1054-1075. [PMID: 33512058 PMCID: PMC8016126 DOI: 10.1002/2211-5463.13099] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 01/07/2021] [Accepted: 01/26/2021] [Indexed: 11/09/2022] Open
Abstract
DNA damage removal by nucleotide excision repair (NER) and replicative bypass via translesion synthesis (TLS) and template switch (TSw) are important in ensuring genome stability. In this study, we tested the applicability of an SV40 large T antigen‐based replication system for the simultaneous examination of these damage tolerance processes. Using both Sanger and next‐generation sequencing combined with lesion‐specific qPCR and replication efficiency studies, we demonstrate that this system works well for studying NER and TLS, especially its one‐polymerase branch, while it is less suited to investigations of homology‐related repair processes, such as TSw. Cis‐syn cyclobutane pyrimidine dimer photoproducts were replicated with equal efficiency to lesion‐free plasmids in vitro, and the majority of TLS on this lesion could be inhibited by a peptide (PIR) specific for the polη‐PCNA interaction interface. TLS on 6–4 pyrimidine–pyrimidone photoproduct proved to be inefficient and was slightly facilitated by PIR as well as by a recombinant ubiquitin‐binding zinc finger domain of polη in HeLa extract, possibly by promoting polymerase exchange. Supplementation of the extract with recombinant PCNA variants indicated the dependence of TLS on PCNA ubiquitylation. In contrast to active TLS and NER, we found no evidence of successful TSw in cellular extracts. The established methods can promote in vitro investigations of replicative DNA damage bypass.
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Affiliation(s)
- Zoltán Szeltner
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, Hungary
| | - Ádám Póti
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, Hungary
| | - Gábor M Harami
- ELTE-MTA "Momentum" Motor Enzymology Research Group, Department of Biochemistry, Eötvös Loránd University, Budapest, Hungary
| | - Mihály Kovács
- ELTE-MTA "Momentum" Motor Enzymology Research Group, Department of Biochemistry, Eötvös Loránd University, Budapest, Hungary.,MTA-ELTE Motor Pharmacology Research Group, Department of Biochemistry, Eötvös Loránd University, Budapest, Hungary
| | - Dávid Szüts
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, Hungary
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19
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Wang X, Zhang W, Jia Y, Wang M, Yi D, Wang TY. Woodchuck hepatitis post-transcriptional regulatory element improves transgene expression and stability mediated by episomal vectors in CHO-K1 cells. Acta Biochim Biophys Sin (Shanghai) 2020; 52:1285-1288. [PMID: 33196825 DOI: 10.1093/abbs/gmaa105] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 08/02/2020] [Accepted: 08/09/2020] [Indexed: 11/13/2022] Open
Affiliation(s)
- Xiaoyin Wang
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang 453003, China
- International Joint Research Laboratory for Recombinant Pharmaceutical Protein Expression System of Henan, Xinxiang Medical University, Xinxiang 453003, China
| | - Weili Zhang
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang 453003, China
| | - Yanlong Jia
- Pharmacy College, Xinxiang Medical University, Xinxiang 453003, China
| | - Meng Wang
- International Joint Research Laboratory for Recombinant Pharmaceutical Protein Expression System of Henan, Xinxiang Medical University, Xinxiang 453003, China
| | - Dandan Yi
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang 453003, China
- International Joint Research Laboratory for Recombinant Pharmaceutical Protein Expression System of Henan, Xinxiang Medical University, Xinxiang 453003, China
| | - Tian-yun Wang
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang 453003, China
- International Joint Research Laboratory for Recombinant Pharmaceutical Protein Expression System of Henan, Xinxiang Medical University, Xinxiang 453003, China
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20
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Cha EB, Shin KK, Seo J, Oh DB. Antibody-secreting macrophages generated using CpG-free plasmid eliminate tumor cells through antibody-dependent cellular phagocytosis. BMB Rep 2020. [PMID: 32438971 PMCID: PMC7473480 DOI: 10.5483/bmbrep.2020.53.8.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The non-viral delivery of genes into macrophages, known as hard-to-transfect cells, is a challenge. In this study, the microporation of a CpG-free and small plasmid (pCGfd-GFP) showed high transfection efficiency, sustainable transgene expression, and good cell viability in the transfections of Raw 264.7 and primary bone marrow-derived macrophages. The non-viral method using the pCGfd vector encoding anti-EGFR single-chain Fv fused with Fc (scFv-Fc) generated the macrophages secreting anti-EGFR scFv-Fc. These macrophages effectively phagocytized tumor cells expressing EGFR through the antibody-dependent mechanism, as was proved by experiments using EGFR-knockout tumor cells. Finally, peri-tumoral injections of anti-EGFR scFv-Fc-secreting macrophages were shown to inhibit tumor growth in the xeno-graft mouse model.
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Affiliation(s)
- Eun Bi Cha
- Environmental Disease Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea
- Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, University of Science and Technology (UST), Daejeon 34113, Korea
| | - Keun Koo Shin
- Environmental Disease Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea
| | - Jinho Seo
- Environmental Disease Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea
| | - Doo-Byoung Oh
- Environmental Disease Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea
- Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, University of Science and Technology (UST), Daejeon 34113, Korea
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21
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Bozza M, Green EW, Espinet E, De Roia A, Klein C, Vogel V, Offringa R, Williams JA, Sprick M, Harbottle RP. Novel Non-integrating DNA Nano-S/MAR Vectors Restore Gene Function in Isogenic Patient-Derived Pancreatic Tumor Models. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2020; 17:957-968. [PMID: 32420409 PMCID: PMC7218229 DOI: 10.1016/j.omtm.2020.04.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 04/22/2020] [Indexed: 12/22/2022]
Abstract
We describe herein non-integrating minimally sized nano-S/MAR DNA vectors, which can be used to genetically modify dividing cells in place of integrating vectors. They represent a unique genetic tool, which avoids vector-mediated damage. Previous work has shown that DNA vectors comprising a mammalian S/MAR element can provide persistent mitotic stability over hundreds of cell divisions, resisting epigenetic silencing and thereby allowing sustained transgene expression. The composition of the original S/MAR vectors does present some inherent limitations that can provoke cellular toxicity. Herein, we present a new system, the nano-S/MAR, which drives higher transgene expression and has improved efficiency of establishment, due to the minimal impact on cellular processes and perturbation of the endogenous transcriptome. We show that these features enable the hitherto challenging genetic modification of patient-derived cells to stably restore the tumor suppressor gene SMAD4 to a patient-derived SMAD4 knockout pancreatic cancer line. Nano-S/MAR modification does not alter the molecular or phenotypic integrity of the patient-derived cells in cell culture and xenograft mouse models. In conclusion, we show that these DNA vectors can be used to persistently modify a range of cells, providing sustained transgene expression while avoiding the risks of insertional mutagenesis and other vector-mediated toxicity.
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Affiliation(s)
- Matthias Bozza
- DNA Vector Research, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 242, 69120 Heidelberg, Germany
| | - Edward W Green
- Neuroimmunology and Brain Tumor Immunology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Elisa Espinet
- Division of Stem Cells and Cancer, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Alice De Roia
- DNA Vector Research, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 242, 69120 Heidelberg, Germany
| | - Corinna Klein
- Stem Cells and Metastasis, Hi-Stem Heidelberg, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Vanessa Vogel
- Stem Cells and Metastasis, Hi-Stem Heidelberg, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Rienk Offringa
- Molecular Oncology of Gastrointestinal Tumors, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | | | - Martin Sprick
- Stem Cells and Metastasis, Hi-Stem Heidelberg, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Richard P Harbottle
- DNA Vector Research, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 242, 69120 Heidelberg, Germany
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22
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Abstract
TelN and tos are a unique DNA linearization unit isolated from bacteriophage N15. While being transferable, the TelN cleaving-rejoining activities remained stable to function on tos in both bacterial and mammalian environments. However, TelN contribution in linear plasmid replication in mammalian cells remains unknown. Herein, we investigated the association of TelN in linear tos-containing DNA (tos-DNA) replication in mammalian cells. Additionally, the mammalian origin of replication (ori) that is well-known to initiate the replication event of plasmid vectors was also studied. In doing so, we identified that both TelN and mammalian initiation sites were essential for the replication of linear tos-DNA, determined by using methylation sensitive DpnI/MboI digestion and polymerase chain reaction (PCR) amplification approaches. Furthermore, we engineered the linear tos-DNA to be able to retain in mammalian cells using S/MAR technology. The resulting S/MAR containing tos-DNA was robust for at least 15 days, with (1) continuous tos-DNA replication, (2) correct splicing of gene transcripts, and (3) stable exogenous gene expression that was statistically comparable to the endogenous gene expression level. Understanding the activities of TelN and tos in mammalian cells can potentially provide insights for adapting this simple DNA linearization unit in developing novel genetic engineering tools, especially to the eukaryotic telomere/telomerase study.
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Affiliation(s)
- Pei Sheng Liew
- School of Science, Monash University Malaysia, Bandar Sunway, 47500 Selangor Darul Ehsan, Malaysia
| | - Tze Hao Tan
- Faculty of Science, Kyushu University, Ito campus, Fukuoka 819-0395, Japan
| | - Yin Cheng Wong
- School of Science, Monash University Malaysia, Bandar Sunway, 47500 Selangor Darul Ehsan, Malaysia
| | - Edmund Ui Hang Sim
- Faculty of Resource Sciences and Technology, University Malaysia Sarawak, 94300 Kota Samarahan, Malaysia
| | - Choon Weng Lee
- Institute of Biological Science, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Kumaran Narayanan
- School of Science, Monash University Malaysia, Bandar Sunway, 47500 Selangor Darul Ehsan, Malaysia
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23
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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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24
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Reus JB, Trivino-Soto GS, Wu LI, Kokott K, Lim ES. SV40 Large T Antigen Is Not Responsible for the Loss of STING in 293T Cells but Can Inhibit cGAS-STING Interferon Induction. Viruses 2020; 12:v12020137. [PMID: 31991682 PMCID: PMC7077178 DOI: 10.3390/v12020137] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 01/21/2020] [Accepted: 01/23/2020] [Indexed: 01/05/2023] Open
Abstract
Several DNA viruses have evolved antagonists to inhibit the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) DNA-sensing immune pathway. This includes DNA viral oncogenes that antagonize the cGAS-STING pathway by binding STING through the LxCxE motif. The 293T human cells are widely used in biology studies as they are highly transfectable. While parental 293 cells express high levels of STING, 293T cells lack STING and are unable to induce interferon antiviral responses to cytosolic DNA. Additionally, 293T cells express the SV40 polyomavirus large T antigen (LT) which enhances the replication of transfected DNA plasmids carrying the SV40 origin of replication. Since SV40 LT also encodes the LxCxE motif, the lack of STING expression in 293T cells is commonly assumed to be due to SV40 large T antigen. We find that SV40 LT does not alter exogenously expressed and endogenous levels of STING protein. We show that STING transcription is suppressed in 293T cells but is not driven by SV40. This study also revealed that SV40 LT does indeed inhibit cGAS-STING interferon induction, but through a mechanism distinct from other DNA virus oncogenes. Collectively, these results indicate that while SV40 LT can inhibit cGAS-STING interferon induction, it does so in an unanticipated manner.
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Affiliation(s)
- Joshua B. Reus
- Center for Fundamental and Applied Microbiomics, Biodesign Institute, Arizona State University, Tempe, AZ 85287, USA
| | - Guillermo S. Trivino-Soto
- Center for Fundamental and Applied Microbiomics, Biodesign Institute, Arizona State University, Tempe, AZ 85287, USA
| | - Lily I. Wu
- Center for Fundamental and Applied Microbiomics, Biodesign Institute, Arizona State University, Tempe, AZ 85287, USA
| | - Kristiana Kokott
- Center for Fundamental and Applied Microbiomics, Biodesign Institute, Arizona State University, Tempe, AZ 85287, USA
| | - Efrem S. Lim
- Center for Fundamental and Applied Microbiomics, Biodesign Institute, Arizona State University, Tempe, AZ 85287, USA
- School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA
- Correspondence:
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25
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Stavrou EF, Simantirakis E, Verras M, Barbas C, Vassilopoulos G, Peterson KR, Athanassiadou A. Episomal vectors based on S/MAR and the β-globin Replicator, encoding a synthetic transcriptional activator, mediate efficient γ-globin activation in haematopoietic cells. Sci Rep 2019; 9:19765. [PMID: 31874995 PMCID: PMC6930265 DOI: 10.1038/s41598-019-56056-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 11/30/2019] [Indexed: 12/19/2022] Open
Abstract
We report the development of episomal vectors for the specific γ-globin transcription activation in its native position by activator Zif-VP64, based on the Scaffold/Matrix Attachment Region (S/MAR) for episomal retention and the β-globin Replicator, the DNA replication-Initiation Region from the β-globin locus. Vector Zif-VP64-Ep1 containing transcription cassettes CMV- Zif-VP64 and CMV-eGFP-S/MAR transfected a)K562 cells; b)murine β-YAC bone marrow cells (BMC); c)human haematopoietic progenitor CD34+ cells, with transfection efficiencies of 46.3 ± 5.2%, 23.0 ± 2.1% and 24.2 ± 2.4% respectively. K562 transfections generated stable cell lines running for 28 weeks with and without selection, with increased levels of γ-globin mRNA by 3.3 ± 0.13, of γ-globin protein by 6.75 ± 3.25 and HbF protein by 2 ± 0.2 fold, while the vector remained episomal and non integrated. In murine β-YAC BMCs the vector mediated the activation of the silent human γ-globin gene and in CD34+ cells, increased γ-globin mRNA, albeit only transiently. A second vector Zif-VP64-Ep2, with both transcription cassettes carrying promoter SFFV instead of CMV and the addition of β-globin Replicator, transferred into CD34+ cells, produced CD34+ eGFP+ cells, that generated colonies in colony forming cell cultures. Importantly, these were 100% fluorescent, with 2.11 ± 0.13 fold increased γ-globin mRNA, compared to non-transfected cells. We consider these episomal vectors valid, safer alternatives to viral vectors.
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Affiliation(s)
- Eleana F Stavrou
- Department of General Biology, School of Medicine, University of Patras, Patras, Greece.
| | - Emannuouil Simantirakis
- Hematology Clinic, Medical School, University of Thessaly and Gene and Cell Therapy Laboratory, BRFAA, Athens, Greece
| | - Meletios Verras
- Department of General Biology, School of Medicine, University of Patras, Patras, Greece
| | - Carlos Barbas
- Skaggs Institute for Chemical Biology, Department of Molecular Biology, Scripps Research Institute, La Jolla, California, USA
| | - George Vassilopoulos
- Hematology Clinic, Medical School, University of Thessaly and Gene and Cell Therapy Laboratory, BRFAA, Athens, Greece
| | - Kenneth R Peterson
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Aglaia Athanassiadou
- Department of General Biology, School of Medicine, University of Patras, Patras, Greece.
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26
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Wang D, Tai PWL, Gao G. Adeno-associated virus vector as a platform for gene therapy delivery. Nat Rev Drug Discov 2019; 18:358-378. [PMID: 30710128 DOI: 10.1038/s41573-019-0012-9] [Citation(s) in RCA: 1222] [Impact Index Per Article: 244.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Adeno-associated virus (AAV) vectors are the leading platform for gene delivery for the treatment of a variety of human diseases. Recent advances in developing clinically desirable AAV capsids, optimizing genome designs and harnessing revolutionary biotechnologies have contributed substantially to the growth of the gene therapy field. Preclinical and clinical successes in AAV-mediated gene replacement, gene silencing and gene editing have helped AAV gain popularity as the ideal therapeutic vector, with two AAV-based therapeutics gaining regulatory approval in Europe or the United States. Continued study of AAV biology and increased understanding of the associated therapeutic challenges and limitations will build the foundation for future clinical success.
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Affiliation(s)
- Dan Wang
- Horae Gene Therapy Center, University of Massachusetts Medical School, Worcester, MA, USA.,Li Weibo Institute for Rare Diseases Research, University of Massachusetts Medical School, Worcester, MA, USA.,Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA, USA
| | - Phillip W L Tai
- Horae Gene Therapy Center, University of Massachusetts Medical School, Worcester, MA, USA.,Li Weibo Institute for Rare Diseases Research, University of Massachusetts Medical School, Worcester, MA, USA.,Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA, USA
| | - Guangping Gao
- Horae Gene Therapy Center, University of Massachusetts Medical School, Worcester, MA, USA. .,Li Weibo Institute for Rare Diseases Research, University of Massachusetts Medical School, Worcester, MA, USA. .,Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA, USA.
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27
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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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28
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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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29
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Efficient episomal gene transfer to human hepatic cells using the pFAR4–S/MAR vector. Mol Biol Rep 2019; 46:3203-3211. [DOI: 10.1007/s11033-019-04777-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 03/20/2019] [Indexed: 12/16/2022]
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30
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Wagner S, McCracken J, Bruszies S, Broadhurst R, Wells DN, Oback B, Bode J, Laible G. Episomal minicircles persist in periods of transcriptional inactivity and can be transmitted through somatic cell nuclear transfer into bovine embryos. Mol Biol Rep 2019; 46:1737-1746. [PMID: 30694456 DOI: 10.1007/s11033-019-04624-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 01/18/2019] [Indexed: 12/14/2022]
Abstract
Episomal plasmids based on a scaffold/matrix attachment region (S/MAR) are extrachromosomal DNA entities that replicate once per cell cycle and are stably maintained in cells or tissue. We generated minicircles, episomal plasmids devoid of bacterial sequences, and show that they are stably transmitted in clonal primary bovine fibroblasts without selection pressure over more than two months. Total DNA, plasmid extraction and fluorescence in situ hybridization (FISH) analyses suggest that the minicircles remained episomal and were not integrated into the genome. Minicircles survived extended periods in serum-starved cells, which indicates that ongoing transcription in non-proliferating cells is not necessary for the maintenance of S/MAR-episomes. To test whether minicircles endure the process of somatic cell nuclear transfer (SCNT), we used cell-cycle synchronized, serum-starved, minicircle-containing cells. Analysis of cells outgrown from SCNT-derived blastocysts shows that the minicircles are maintained through SCNT and early embryonic development, which raises the prospect of using cell lines with episomal minicircles for the generation of transgenic animals.
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Affiliation(s)
- Stefan Wagner
- AgResearch Limited, Ruakura Research Centre, Hamilton, 3240, New Zealand. .,Rowett Institute, University of Aberdeen, Aberdeen, AB25 2ZD, UK.
| | - Judi McCracken
- AgResearch Limited, Ruakura Research Centre, Hamilton, 3240, New Zealand
| | - Sabine Bruszies
- AgResearch Limited, Ruakura Research Centre, Hamilton, 3240, New Zealand
| | - Ric Broadhurst
- AgResearch Limited, Ruakura Research Centre, Hamilton, 3240, New Zealand
| | - David N Wells
- AgResearch Limited, Ruakura Research Centre, Hamilton, 3240, New Zealand
| | - Björn Oback
- AgResearch Limited, Ruakura Research Centre, Hamilton, 3240, New Zealand
| | - Jürgen Bode
- Hannover Medical School (MHH), Carl-Neuberg-Strasse 1, 30625, Hannover, Germany
| | - Götz Laible
- AgResearch Limited, Ruakura Research Centre, Hamilton, 3240, New Zealand
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31
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Quiviger M, Giannakopoulos A, Verhenne S, Marie C, Stavrou EF, Vanhoorelbeke K, Izsvák Z, De Meyer SF, Athanassiadou A, Scherman D. Improved molecular platform for the gene therapy of rare diseases by liver protein secretion. Eur J Med Genet 2018; 61:723-728. [PMID: 29704684 DOI: 10.1016/j.ejmg.2018.04.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 03/26/2018] [Accepted: 04/22/2018] [Indexed: 11/26/2022]
Abstract
Many rare monogenic diseases are treated by protein replacement therapy, in which the missing protein is repetitively administered to the patient. However, in several cases, the missing protein is required at a high and sustained level, which renders protein therapy far from being adequate. As an alternative, a gene therapy treatment ensuring a sustained effectiveness would be particularly valuable. Liver is an optimal organ for the secretion and systemic distribution of a therapeutic transgene product. Cutting edge non-viral gene therapy tools were tested in order to produce a high and sustained level of therapeutic protein secretion by the liver using the hydrodynamic delivery technique. The use of S/MAR matrix attachment region provided a slight, however not statistically significant, increase in the expression of a reporter gene in the liver. We have selected the von Willebrand Factor (vWF) gene as a particularly challenging large gene (8.4 kb) for liver delivery and expression, and also because a high vWF blood concentration is required for disease correction. By using the optimized miniplasmid pFAR free of antibiotic resistance gene together with the Sleeping Beauty transposon and the hyperactive SB100X transposase, we have obtained a sustainable level of vWFblood secretion by the liver, at 65% of physiological level. Our results point to the general use of this plasmid platform using the liver as a protein factory to treat numerous rare disorders by gene therapy.
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Affiliation(s)
- Mickael Quiviger
- Laboratory of Chemical and Biological Technologies for Health, Université Paris Descartes, Sorbonne-Paris-Cité, F-75006 Paris, France; CNRS, UTCBS UMR 8258, F-75006 Paris, France; Chimie ParisTech, PSL Research University, UTCBS, F-75005 Paris, France; INSERM, UTCBS U 1022, F-75006 Paris, France
| | | | - Sebastien Verhenne
- Laboratory for Thrombosis Research, KU Leuven Campus Kulak Kortrijk, Kortrijk, Belgium
| | - Corinne Marie
- Laboratory of Chemical and Biological Technologies for Health, Université Paris Descartes, Sorbonne-Paris-Cité, F-75006 Paris, France; CNRS, UTCBS UMR 8258, F-75006 Paris, France; Chimie ParisTech, PSL Research University, UTCBS, F-75005 Paris, France; INSERM, UTCBS U 1022, F-75006 Paris, France
| | - Eleana F Stavrou
- Department of General Biology, Medical School, University of Patras, Rion, Greece
| | - Karen Vanhoorelbeke
- Laboratory for Thrombosis Research, KU Leuven Campus Kulak Kortrijk, Kortrijk, Belgium
| | - Zsuzsanna Izsvák
- Mobile DNA, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
| | - Simon F De Meyer
- Laboratory for Thrombosis Research, KU Leuven Campus Kulak Kortrijk, Kortrijk, Belgium
| | - Aglaia Athanassiadou
- Department of General Biology, Medical School, University of Patras, Rion, Greece
| | - Daniel Scherman
- Laboratory of Chemical and Biological Technologies for Health, Université Paris Descartes, Sorbonne-Paris-Cité, F-75006 Paris, France; CNRS, UTCBS UMR 8258, F-75006 Paris, France; Chimie ParisTech, PSL Research University, UTCBS, F-75005 Paris, France; INSERM, UTCBS U 1022, F-75006 Paris, France.
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32
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Assembly and Functional Analysis of an S/MAR Based Episome with the Cystic Fibrosis Transmembrane Conductance Regulator Gene. Int J Mol Sci 2018; 19:ijms19041220. [PMID: 29673202 PMCID: PMC5979583 DOI: 10.3390/ijms19041220] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2018] [Revised: 04/05/2018] [Accepted: 04/09/2018] [Indexed: 12/24/2022] Open
Abstract
Improving the efficacy of gene therapy vectors is still an important goal toward the development of safe and efficient gene therapy treatments. S/MAR (scaffold/matrix attached region)-based vectors are maintained extra-chromosomally in numerous cell types, which is similar to viral-based vectors. Additionally, when established as an episome, they show a very high mitotic stability. In the present study we tested the idea that addition of an S/MAR element to a CFTR (cystic fibrosis transmembrane conductance regulator) expression vector, may allow the establishment of a CFTR episome in bronchial epithelial cells. Starting from the observation that the S/MAR vector pEPI-EGFP (enhanced green fluorescence protein) is maintained as an episome in human bronchial epithelial cells, we assembled the CFTR vector pBQ-S/MAR. This vector, transfected in bronchial epithelial cells with mutated CFTR, supported long term wt CFTR expression and activity, which in turn positively impacted on the assembly of tight junctions in polarized epithelial cells. Additionally, the recovery of intact pBQ-S/MAR, but not the parental vector lacking the S/MAR element, from transfected cells after extensive proliferation, strongly suggested that pBQ-S/MAR was established as an episome. These results add a new element, the S/MAR, that can be considered to improve the persistence and safety of gene therapy vectors for cystic fibrosis pulmonary disease.
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33
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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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34
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Bruter AV, Kandarakov OF, Belyavsky AV. Persistence of plasmid-mediated expression of transgenes in human mesenchymal stem cells depends primarily on CpG levels of both vector and transgene. J Gene Med 2018; 20:e3009. [DOI: 10.1002/jgm.3009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 01/20/2018] [Accepted: 01/20/2018] [Indexed: 01/25/2023] Open
Affiliation(s)
- Alexandra V. Bruter
- Russian Academy of Sciences; Engelhardt Institute of Molecular Biology; Moscow Russia
| | - Oleg F. Kandarakov
- Russian Academy of Sciences; Engelhardt Institute of Molecular Biology; Moscow Russia
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35
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Viarisio D, Müller-Decker K, Accardi R, Robitaille A, Dürst M, Beer K, Jansen L, Flechtenmacher C, Bozza M, Harbottle R, Voegele C, Ardin M, Zavadil J, Caldeira S, Gissmann L, Tommasino M. Beta HPV38 oncoproteins act with a hit-and-run mechanism in ultraviolet radiation-induced skin carcinogenesis in mice. PLoS Pathog 2018; 14:e1006783. [PMID: 29324843 PMCID: PMC5764406 DOI: 10.1371/journal.ppat.1006783] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 11/30/2017] [Indexed: 11/19/2022] Open
Abstract
Cutaneous beta human papillomavirus (HPV) types are suspected to be involved, together with ultraviolet (UV) radiation, in the development of non-melanoma skin cancer (NMSC). Studies in in vitro and in vivo experimental models have highlighted the transforming properties of beta HPV E6 and E7 oncoproteins. However, epidemiological findings indicate that beta HPV types may be required only at an initial stage of carcinogenesis, and may become dispensable after full establishment of NMSC. Here, we further investigate the potential role of beta HPVs in NMSC using a Cre-loxP-based transgenic (Tg) mouse model that expresses beta HPV38 E6 and E7 oncogenes in the basal layer of the skin epidermis and is highly susceptible to UV-induced carcinogenesis. Using whole-exome sequencing, we show that, in contrast to WT animals, when exposed to chronic UV irradiation K14 HPV38 E6/E7 Tg mice accumulate a large number of UV-induced DNA mutations, which increase proportionally with the severity of the skin lesions. The mutation pattern detected in the Tg skin lesions closely resembles that detected in human NMSC, with the highest mutation rate in p53 and Notch genes. Using the Cre-lox recombination system, we observed that deletion of the viral oncogenes after development of UV-induced skin lesions did not affect the tumour growth. Together, these findings support the concept that beta HPV types act only at an initial stage of carcinogenesis, by potentiating the deleterious effects of UV radiation. Many epidemiological and biological findings support the hypothesis that beta HPV types cooperate with UV radiation in the induction of NMSC, the most common form of human cancer. We have previously shown that K14 HPV38 E6/E7 Tg mice, when exposed to long-term UV radiation, developed NMSC, whereas WT animals subjected to identical treatments did not develop any type of skin lesions. Here, we show that the high skin cancer susceptibility of these Tg animals tightly correlates with their tendency to accumulate UV-induced mutations in genes that are frequently mutated in human NMSC. Importantly, deletion of the HPV38 E6 and E7 genes in existing skin lesions did not affect the further growth of the cancer cells. Together, these findings support the model that beta HPV infection is a co-factor in skin carcinogenesis, facilitating the accumulation of the UV-induced DNA mutations.
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Affiliation(s)
| | | | - Rosita Accardi
- International Agency for Research on Cancer, World Health Organization, Lyon, France
| | - Alexis Robitaille
- International Agency for Research on Cancer, World Health Organization, Lyon, France
| | - Matthias Dürst
- Department of Gynecology, Jena University Hospital - Friedrich Schiller University, Jena, Germany
| | - Katrin Beer
- Department of Gynecology, Jena University Hospital - Friedrich Schiller University, Jena, Germany
| | - Lars Jansen
- Department of Gynecology, Jena University Hospital - Friedrich Schiller University, Jena, Germany
| | | | | | | | - Catherine Voegele
- International Agency for Research on Cancer, World Health Organization, Lyon, France
| | - Maude Ardin
- International Agency for Research on Cancer, World Health Organization, Lyon, France
| | - Jiri Zavadil
- International Agency for Research on Cancer, World Health Organization, Lyon, France
| | | | - Lutz Gissmann
- Deutsches Krebsforschungszentrum, Heidelberg, Germany
- Department of Botany and Microbiology (honorary member), King Saud University, Riyadh, Saudi Arabia
| | - Massimo Tommasino
- International Agency for Research on Cancer, World Health Organization, Lyon, France
- * E-mail:
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36
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Hagedorn C, Gogol-Döring A, Schreiber S, Epplen JT, Lipps HJ. Genome-wide profiling of S/MAR-based replicon contact sites. Nucleic Acids Res 2017; 45:7841-7854. [PMID: 28609784 PMCID: PMC5570033 DOI: 10.1093/nar/gkx522] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 06/05/2017] [Indexed: 11/14/2022] Open
Abstract
Autonomously replicating vectors represent a simple and versatile model system for genetic modifications, but their localization in the nucleus and effect on endogenous gene expression is largely unknown. Using circular chromosome conformation capture we mapped genomic contact sites of S/MAR-based replicons in HeLa cells. The influence of cis-active sequences on genomic localization was assessed using replicons containing either an insulator sequence or an intron. While the original and the insulator-containing replicons displayed distinct contact sites, the intron-containing replicon showed a rather broad genomic contact pattern. Our results indicate a preference for certain chromatin structures and a rather non-dynamic behaviour during mitosis. Independent of inserted cis-active elements established vector molecules reside preferentially within actively transcribed regions, especially within promoter sequences and transcription start sites. However, transcriptome analyses revealed that established S/MAR-based replicons do not alter gene expression profiles of host genome. Knowledge of preferred contact sites of exogenous DNA, e.g. viral or non-viral episomes, contribute to our understanding of episome behaviour in the nucleus and can be used for vector improvement and guiding of DNA sequences to specific subnuclear sites.
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Affiliation(s)
- Claudia Hagedorn
- University of Witten/Herdecke, ZBAF, Institute of Cell Biology, Stockumer Strasse 10, 58453 Witten, Germany
| | - Andreas Gogol-Döring
- Technische Hochschule Mittelhessen (University of Applied Sciences), Department of Bioinformatics, Wiesenstrasse 14, 35390 Gießen, Germany
| | - Sabrina Schreiber
- Department of Human Genetics, Ruhr-University, Universitätsstraße 150, 44801 Bochum, Germany
| | - Jörg T Epplen
- University of Witten/Herdecke, ZBAF, Institute of Cell Biology, Stockumer Strasse 10, 58453 Witten, Germany.,Department of Human Genetics, Ruhr-University, Universitätsstraße 150, 44801 Bochum, Germany
| | - Hans J Lipps
- University of Witten/Herdecke, ZBAF, Institute of Cell Biology, Stockumer Strasse 10, 58453 Witten, Germany
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Initial Considerations Before Designing a Promoter Construct. Methods Mol Biol 2017. [PMID: 28801895 DOI: 10.1007/978-1-4939-7223-4_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Before designing a synthetic promoter, it can be helpful to think about its final application. Is the study purely an in vitro exercise in monitoring short-term promoter activity from an episomal vector, or does the promoter eventually need to be permanently active and be integrated into the genome or perhaps even to function in vivo? The final application will have a bearing on promoter design and vector of choice from the start of the study. In this chapter I highlight some of the vector attributes to consider and features that should be thought about.
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Hagedorn C, Schnödt-Fuchs M, Boehme P, Abdelrazik H, Lipps HJ, Büning H. S/MAR Element Facilitates Episomal Long-Term Persistence of Adeno-Associated Virus Vector Genomes in Proliferating Cells. Hum Gene Ther 2017; 28:1169-1179. [PMID: 28665147 DOI: 10.1089/hum.2017.025] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Adeno-associated virus (AAV) vectors are one of the most frequently applied gene transfer systems in research and human clinical trials. Since AAV vectors do not possess an integrase activity, application is restricted to terminally differentiated tissues if transgene expression is required long term. To overcome this limitation and to generate AAV vectors that persist episomally in dividing cells, AAV vector genomes were equipped with a scaffold/matrix attachment region (S/MAR). After a mild antibiotic selection, cells transduced with AAV-S/MAR established colonies that maintained long-term transgene expression (>50 population doublings) from replicating AAV vector episomes in the absence of further selection. Unexpectedly, with a lesser but still significant efficiency, the control vector (AAV-ΔS/MAR), a standard single-stranded AAV vector, also established stable transgene-expressing colonies, most of which were maintained as replicating episomes rather than integrated vector genomes. Thus, based on the result in HeLa cells, it is concluded that AAV vector genomes per se possess the ability to establish episomal maintenance in proliferating cells, a feature that can be enhanced by incorporation of a foreign genomic element such as an S/MAR element.
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Affiliation(s)
- Claudia Hagedorn
- 1 Institute of Cell Biology, ZBAF, University of Witten/Herdecke , Witten, Germany
| | - Maria Schnödt-Fuchs
- 2 Laboratory for AAV Vector Development, Center for Molecular Medicine Cologne (CMMC), University of Cologne , Cologne, Germany .,3 Department I of Internal Medicine, University Hospital Cologne , Cologne, Germany .,4 German Center for Infection Research (DZIF) , partner sites Bonn-Cologne and Hannover-Braunschweig
| | - Philip Boehme
- 1 Institute of Cell Biology, ZBAF, University of Witten/Herdecke , Witten, Germany .,5 Institute of Virology and Microbiology, ZBAF, University of Witten/Herdecke , Witten, Germany
| | - Heba Abdelrazik
- 2 Laboratory for AAV Vector Development, Center for Molecular Medicine Cologne (CMMC), University of Cologne , Cologne, Germany .,6 Clinical Pathology Department, Faculty of Medicine, Cairo University , Cairo, Egypt
| | - Hans J Lipps
- 1 Institute of Cell Biology, ZBAF, University of Witten/Herdecke , Witten, Germany
| | - Hildegard Büning
- 2 Laboratory for AAV Vector Development, Center for Molecular Medicine Cologne (CMMC), University of Cologne , Cologne, Germany .,3 Department I of Internal Medicine, University Hospital Cologne , Cologne, Germany .,4 German Center for Infection Research (DZIF) , partner sites Bonn-Cologne and Hannover-Braunschweig.,7 Laboratory for Infection Biology and Gene Transfer, Institute of Experimental Hematology, Hannover Medical School , Hannover, Germany
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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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Sequence-Modified Antibiotic Resistance Genes Provide Sustained Plasmid-Mediated Transgene Expression in Mammals. Mol Ther 2017; 25:1187-1198. [PMID: 28365028 DOI: 10.1016/j.ymthe.2017.03.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Revised: 02/26/2017] [Accepted: 03/02/2017] [Indexed: 02/05/2023] Open
Abstract
Conventional plasmid vectors are incapable of achieving sustained levels of transgene expression in vivo even in quiescent mammalian tissues because the transgene expression cassette is silenced. Transcriptional silencing results from the presence of the bacterial plasmid backbone or virtually any DNA sequence of >1 kb in length placed outside of the expression cassette. Here, we show that transcriptional silencing can be substantially forestalled by increasing the An/Tn sequence composition in the plasmid bacterial backbone. Increasing numbers of An/Tn sequences increased sustained transcription of both backbone sequences and adjacent expression cassettes. In order to recapitulate these expression profiles in compact and portable plasmid DNA backbones, we engineered the standard kanamycin or ampicillin antibiotic resistance genes, optimizing the number of An/Tn sequence without altering the encoded amino acids. The resulting vector backbones yield sustained transgene expression from mouse liver, providing generic DNA vectors capable of sustained transgene expression without additional genes or mammalian regulatory elements.
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41
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Saraiva SM, Castro-López V, Pañeda C, Alonso MJ. Synthetic nanocarriers for the delivery of polynucleotides to the eye. Eur J Pharm Sci 2017; 103:5-18. [PMID: 28263915 DOI: 10.1016/j.ejps.2017.03.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 02/28/2017] [Accepted: 03/01/2017] [Indexed: 02/07/2023]
Abstract
This review is a comprehensive analysis of the progress made so far on the delivery of polynucleotide-based therapeutics to the eye, using synthetic nanocarriers. Attention has been addressed to the capacity of different nanocarriers for the specific delivery of polynucleotides to both, the anterior and posterior segments of the eye, with emphasis on their ability to (i) improve the transport of polynucleotides across the different eye barriers; (ii) promote their intracellular penetration into the target cells; (iii) protect them against degradation and, (iv) deliver them in a long-term fashion way. Overall, the conclusion is that despite the advantages that nanotechnology may offer to the area of ocular polynucleotide-based therapies (especially AS-ODN and siRNA delivery), the knowledge disclosed so far is still limited. This fact underlines the necessity of more fundamental and product-oriented research for making the way of the said nanotherapies towards clinical translation.
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Affiliation(s)
- Sofia M Saraiva
- Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), Av. Barcelona s/n, Campus Vida, Universidade de Santiago de Compostela, 15706 Santiago de Compostela, Spain
| | - Vanessa Castro-López
- Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), Av. Barcelona s/n, Campus Vida, Universidade de Santiago de Compostela, 15706 Santiago de Compostela, Spain
| | - Covadonga Pañeda
- Sylentis, R&D Department, c/Santiago Grisolía 2, 28760 Tres Cantos, Madrid, Spain
| | - María José Alonso
- Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), Av. Barcelona s/n, Campus Vida, Universidade de Santiago de Compostela, 15706 Santiago de Compostela, Spain; Department of Pharmacy and Pharmaceutical Technology, School of Pharmacy, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain; Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain.
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42
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Chen F, Qi X, Zhang R, Wu ZY, Yan CE, Li J, Liu QY, Qi J. Episomal lentiviral vectors confer erythropoietin expression in dividing cells. Plasmid 2017; 90:15-19. [PMID: 28189631 DOI: 10.1016/j.plasmid.2017.02.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2016] [Revised: 02/05/2017] [Accepted: 02/07/2017] [Indexed: 01/07/2023]
Abstract
Lentiviral vectors are now widely considered as one of the most common gene delivery tools for dividing and non-dividing cells. However, insertional mutagenesis has been found in clinical trials with retroviral vectors, which poses a safety risk. The use of non-integrating lentiviral (NIL) vectors, which avoid integration, eliminates the insertional mutagenesis problem. These NIL vectors are unable to mediate stable gene delivery into dividing cells, which makes them of limited use in the clinical practice of gene therapy. In this study, we constructed a NIL vector which harbors the scaffold/matrix attachment region (S/MAR) sequence and a therapeutic gene. NIL retained episomal erythropoietin (EPO) gene expression for 74days in dividing cells both with and without selection. Furthermore, Southern blot analysis showed that the NIL vector was retained extrachromosomally in CHO cells. In conclusion, the NIL vector based on an S/MAR sequence retained the extrachromosomal expression of a therapeutic gene in dividing cells. Our results show that NIL vectors maybe a safe and effective means of gene delivery, which is of potential clinical significance.
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Affiliation(s)
- Feng Chen
- Department of Clinical Laboratory, Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 10021, PR China.
| | - Xin Qi
- Department of Clinical Laboratory, China-Japan Union Hospital of Jilin University, Changchun 130031, Jilin, PR China
| | - Rong Zhang
- Department of Clinical Laboratory, Central Hospital of Qingdao, Qingdao 266042, Shandong, PR China
| | - Zong-Yong Wu
- Department of Clinical Laboratory, Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 10021, PR China
| | - Cui-E Yan
- Department of Clinical Laboratory, Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 10021, PR China
| | - Jia Li
- Department of Clinical Laboratory, Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 10021, PR China
| | - Qiu-Ying Liu
- Department of Clinical Laboratory, Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 10021, PR China
| | - Jun Qi
- Department of Clinical Laboratory, Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 10021, PR China
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43
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Stavrou EF, Lazaris VM, Giannakopoulos A, Papapetrou E, Spyridonidis A, Zoumbos NC, Gkountis A, Athanassiadou A. The β-globin Replicator greatly enhances the potential of S/MAR based episomal vectors for gene transfer into human haematopoietic progenitor cells. Sci Rep 2017; 7:40673. [PMID: 28106085 PMCID: PMC5247744 DOI: 10.1038/srep40673] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 12/09/2016] [Indexed: 11/08/2022] Open
Abstract
Specific human chromosomal elements enhance the performance of episomal gene-transfer vectors. S/MAR-based episomal vector pEPI-eGFP transfects CD34+ haematopoietic cells, but only transiently. To address this issue we reinforced (1) transgene transcription by replacing the CMV promoter driving eGFP with the EF1/HTLV or SFFV promoters to produce vectors pEPI-EF1/HTLV and pEPI-SFFV, respectively; and (2) plasmid replication by inserting the replication-Initiation Region (IR) from the β-globin locus into vector pEPI-SFFV to produce vector pEP-IR. All vectors supported stable transfections in K562 cells. Transfections of CD34+ cells from peripheral blood of healthy donors reached 30% efficiency. Upon evaluation of CD34+/eGFP+ cells in colony-forming cell (CFC) assays, vector pEP-IR showed superior performance after 14 days, by fluorescent microscopy: 100% eGFP+-colonies against 0% for pEPI-eGFP, 56.9% for pEPI-SFFV and 49.8% for pEPI-EF1/HTLV; 50% more plasmid copies per cell and 3-fold eGFP expression compared to the latter two constructs, by quantitative (q)PCR and RT-qPCR, respectively. Importantly, the establishment rate in CFC assays was 15% for pEP-IR against 5.5% for pEPI-SFFV and 5% for pEPI-EF1/HTLV. Vector pEP-IR shows extremely low delivery rate but supports eGFP expression in thalassaemic mouse haematopoietic progenitor cells. The IR is a novel human control element for improved episomal gene transfer into progenitor cells.
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Affiliation(s)
- Eleana F. Stavrou
- Department of General Biology, School of Medicine, University of Patras, Greece
| | | | | | - Eirini Papapetrou
- Department of General Biology, School of Medicine, University of Patras, Greece
| | - Alexandros Spyridonidis
- Haematology Unit Department of Internal Medicine, School of Medicine, University of Patras, Greece
| | - Nikolas C. Zoumbos
- Haematology Unit Department of Internal Medicine, School of Medicine, University of Patras, Greece
| | - Antonis Gkountis
- Gene and Cell Therapy Center, Haematology Department-BMT Unit, George Papanicolaou Hospital, Thessaloniki, Greece
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44
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Šimčíková M, Prather KLJ, Prazeres DMF, Monteiro GA. Towards effective non-viral gene delivery vector. Biotechnol Genet Eng Rev 2017; 31:82-107. [PMID: 27160661 DOI: 10.1080/02648725.2016.1178011] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Despite very good safety records, clinical trials using plasmid DNA failed due to low transfection efficiency and brief transgene expression. Although this failure is both due to poor plasmid design and to inefficient delivery methods, here we will focus on the former. The DNA elements like CpG motifs, selection markers, origins of replication, cryptic eukaryotic signals or nuclease-susceptible regions and inverted repeats showed detrimental effects on plasmids' performance as biopharmaceuticals. On the other hand, careful selection of promoter, polyadenylation signal, codon optimization and/or insertion of introns or nuclear-targeting sequences for therapeutic protein expression can enhance the clinical efficacy. Minimal vectors, which are devoid of the bacterial backbone and consist exclusively of the eukaryotic expression cassette, demonstrate better performance in terms of expression levels, bioavailability, transfection rates and increased therapeutic effects. Although the results are promising, minimal vectors have not taken over the conventional plasmids in clinical trials due to challenging manufacturing issues.
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Affiliation(s)
- Michaela Šimčíková
- a MIT-Portugal Program.,b iBB-Institute for Bioengineering and Biosciences , Lisbon , Portugal
| | - Kristala L J Prather
- a MIT-Portugal Program.,c Department of Chemical Engineering , Massachusetts Institute of Technology , Cambridge , MA , USA
| | - Duarte M F Prazeres
- a MIT-Portugal Program.,c Department of Chemical Engineering , Massachusetts Institute of Technology , Cambridge , MA , USA.,d Department of Bioengineering , Instituto Superior Técnico , Lisbon , Portugal
| | - Gabriel A Monteiro
- a MIT-Portugal Program.,c Department of Chemical Engineering , Massachusetts Institute of Technology , Cambridge , MA , USA.,d Department of Bioengineering , Instituto Superior Técnico , Lisbon , Portugal
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45
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Xu Z, Chen F, Zhang L, Lu J, Xu P, Liu G, Xie X, Mu W, Wang Y, Liu D. Non-integrating lentiviral vectors based on the minimal S/MAR sequence retain transgene expression in dividing cells. SCIENCE CHINA-LIFE SCIENCES 2016; 59:1024-1033. [PMID: 27614752 DOI: 10.1007/s11427-016-0067-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 07/21/2016] [Indexed: 01/10/2023]
Abstract
Safe and efficient gene transfer systems are the basis of gene therapy applications. Non-integrating lentiviral (NIL) vectors are among the most promising candidates for gene transfer tools, because they exhibit high transfer efficiency in both dividing and non-dividing cells and do not present a risk of insertional mutagenesis. However, non-integrating lentiviral vectors cannot introduce stable exogenous gene expression to dividing cells, thereby limiting their application. Here, we report the design of a non-integrating lentiviral vector that contains the minimal scaffold/matrix attachment region (S/MAR) sequence (SNIL), and this SNIL vector is able to retain episomal transgene expression in dividing cells. Using SNIL vectors, we detected the expression of the eGFP gene for 61 days in SNIL-transduced stable CHO cells, either with selection or not. In the NIL group without the S/MAR sequence, however, the transduced cells died under selection for the transient expression of NIL vectors. Furthermore, Southern blot assays demonstrated that the SNIL vectors were retained extrachromosomally in the CHO cells. In conclusion, the minimal S/MAR sequence retained the non-integrating lentiviral vectors in dividing cells, which indicates that SNIL vectors have the potential for use as a gene transfer tool.
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Affiliation(s)
- Zhen Xu
- State Key Laboratory of Medical Molecular Biology, Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100005, China
| | - Feng Chen
- State Key Laboratory of Medical Molecular Biology, Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100005, China
| | - Lingling Zhang
- State Key Laboratory of Medical Molecular Biology, Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100005, China
| | - Jing Lu
- State Key Laboratory of Medical Molecular Biology, Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100005, China
| | - Peng Xu
- State Key Laboratory of Medical Molecular Biology, Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100005, China
| | - Guang Liu
- State Key Laboratory of Medical Molecular Biology, Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100005, China
| | - Xuemin Xie
- State Key Laboratory of Medical Molecular Biology, Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100005, China
| | - Wenli Mu
- State Key Laboratory of Medical Molecular Biology, Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100005, China
| | - Yajun Wang
- State Key Laboratory of Medical Molecular Biology, Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100005, China
| | - Depei Liu
- State Key Laboratory of Medical Molecular Biology, Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100005, China.
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Jin C, Fotaki G, Ramachandran M, Nilsson B, Essand M, Yu D. Safe engineering of CAR T cells for adoptive cell therapy of cancer using long-term episomal gene transfer. EMBO Mol Med 2016; 8:702-11. [PMID: 27189167 PMCID: PMC4931286 DOI: 10.15252/emmm.201505869] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Chimeric antigen receptor (CAR) T‐cell therapy is a new successful treatment for refractory B‐cell leukemia. Successful therapeutic outcome depends on long‐term expression of CAR transgene in T cells, which is achieved by delivering transgene using integrating gamma retrovirus (RV) or lentivirus (LV). However, uncontrolled RV/LV integration in host cell genomes has the potential risk of causing insertional mutagenesis. Herein, we describe a novel episomal long‐term cell engineering method using non‐integrating lentiviral (NILV) vector containing a scaffold/matrix attachment region (S/MAR) element, for either expression of transgenes or silencing of target genes. The insertional events of this vector into the genome of host cells are below detection level. CD19 CAR T cells engineered with a NILV‐S/MAR vector have similar levels of CAR expression as T cells engineered with an integrating LV vector, even after numerous rounds of cell division. NILV‐S/MAR‐engineered CD19 CAR T cells exhibited similar cytotoxic capacity upon CD19+ target cell recognition as LV‐engineered T cells and are as effective in controlling tumor growth in vivo. We propose that NILV‐S/MAR vectors are superior to current options as they enable long‐term transgene expression without the risk of insertional mutagenesis and genotoxicity.
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Affiliation(s)
- Chuan Jin
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Grammatiki Fotaki
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Mohanraj Ramachandran
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Berith Nilsson
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Magnus Essand
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Di Yu
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
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47
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Impact of Different Promoters on Episomal Vectors Harbouring Characteristic Motifs of Matrix Attachment Regions. Sci Rep 2016; 6:26446. [PMID: 27226236 PMCID: PMC4881036 DOI: 10.1038/srep26446] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 04/29/2016] [Indexed: 12/19/2022] Open
Abstract
We previously demonstrated that the characteristic sequence of matrix attachment regions (MARs) allows transgenes to be maintained episomally in CHO cells. In the present study, six commonly used promoters from human cytomegalovirus major immediate-early (CMV), simian vacuolating virus 40 (SV40), Rous sarcoma virus, Homo sapiens ubiquitin C, phosphoglycerate kinase, and β-globin, respectively, were evaluated to determine their effects on transgene expression and stability in CHO cells stably transfected via the episomal vector harbouring characteristic MAR motifs. The CHO cells were transfected with vectors and then screened using G418, after which the stably transfected cells were split into two and further cultured either in the presence or absence of G418. Of the six promoters, the CMV promoter yielded the highest transgene expression levels and the highest transfection efficiency, whereas the SV40 promoter maintained transgene expression more stably during long-term culture than the other promoters did. The CMV and SV40 promoter-containing vectors were furthermore episomally maintained and conferred sustained eGFP expression in the cells even under nonselective conditions. On the basis of these findings, we conclude that the CMV promoter performs best in terms of yielding both high expression levels and high levels of stability using this episomal vector system.
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48
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Neal JA, Xu Y, Abe M, Hendrickson E, Meek K. Restoration of ATM Expression in DNA-PKcs-Deficient Cells Inhibits Signal End Joining. THE JOURNAL OF IMMUNOLOGY 2016; 196:3032-42. [PMID: 26921311 DOI: 10.4049/jimmunol.1501654] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 01/26/2016] [Indexed: 11/19/2022]
Abstract
Unlike most DNA-dependent protein kinase, catalytic subunit (DNA-PKcs)-deficient mouse cell strains, we show in the present study that targeted deletion of DNA-PKcs in two different human cell lines abrogates VDJ signal end joining in episomal assays. Although the mechanism is not well defined, DNA-PKcs deficiency results in spontaneous reduction of ATM expression in many cultured cell lines (including those examined in this study) and in DNA-PKcs-deficient mice. We considered that varying loss of ATM expression might explain differences in signal end joining in different cell strains and animal models, and we investigated the impact of ATM and/or DNA-PKcs loss on VDJ recombination in cultured human and rodent cell strains. To our surprise, in DNA-PKcs-deficient mouse cell strains that are proficient in signal end joining, restoration of ATM expression markedly inhibits signal end joining. In contrast, in DNA-PKcs-deficient cells that are deficient in signal end joining, complete loss of ATM enhances signal (but not coding) joint formation. We propose that ATM facilitates restriction of signal ends to the classical nonhomologous end-joining pathway.
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Affiliation(s)
- Jessica A Neal
- Department of Microbiology and Molecular Genetics, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824; Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824
| | - Yao Xu
- Department of Microbiology and Molecular Genetics, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824; Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824
| | - Masumi Abe
- National Institute of Radiological Sciences, Chiba 263-8555, Japan; and
| | - Eric Hendrickson
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota Medical School, Minneapolis, MN 55455
| | - Katheryn Meek
- Department of Microbiology and Molecular Genetics, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824; Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824;
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49
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Rizwani W, Chellappan SP. In vitro replication assay with mammalian cell extracts. Methods Mol Biol 2015; 1288:349-62. [PMID: 25827890 DOI: 10.1007/978-1-4939-2474-5_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Regulatory mechanisms are crucial to control DNA replication during cell cycle in eukaryotic cells. Cell-free in vitro replication assay (IVRA) is one of the widely used assays to understand the complex mammalian replication system. IVRA can provide a snapshot of the regulatory mechanisms controlling replication in higher eukaryotes by using a single plasmid, pEPI-1. This chapter outlines the general strategies and protocols used to perform IVRA to study the differential recruitment of replication factors either independently or in combination, based on the experience in studying the role of prohibitin in replication as well as other published protocols. This method can be employed to identify not only proteins that assist replication but also proteins that inhibit replication of mammalian genome.
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Affiliation(s)
- Wasia Rizwani
- Department of Biochemistry, Osmania University, Hyderabad, Telangana, 500 007, India,
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50
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Zulliger R, Conley SM, Naash MI. Non-viral therapeutic approaches to ocular diseases: An overview and future directions. J Control Release 2015; 219:471-487. [PMID: 26439665 PMCID: PMC4699668 DOI: 10.1016/j.jconrel.2015.10.007] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Revised: 10/01/2015] [Accepted: 10/02/2015] [Indexed: 12/31/2022]
Abstract
Currently there are no viable treatment options for patients with debilitating inherited retinal degeneration. The vast variability in disease-inducing mutations and resulting phenotypes has hampered the development of therapeutic interventions. Gene therapy is a logical approach, and recent work has focused on ways to optimize vector design and packaging to promote optimized expression and phenotypic rescue after intraocular delivery. In this review, we discuss ongoing ocular clinical trials, which currently use viral gene delivery, but focus primarily on new advancements in optimizing the efficacy of non-viral gene delivery for ocular diseases. Non-viral delivery systems are highly customizable, allowing functionalization to improve cellular and nuclear uptake, bypassing cellular degradative machinery, and improving gene expression in the nucleus. Non-viral vectors often yield transgene expression levels lower than viral counterparts, however their favorable safety/immune profiles and large DNA capacity (critical for the delivery of large ocular disease genes) make their further development a research priority. Recent work on particle coating and vector engineering presents exciting ways to overcome limitations of transient/low gene expression levels, but also highlights the fact that further refinements are needed before use in the clinic.
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Affiliation(s)
- Rahel Zulliger
- Department of Biomedical Engineering, University of Houston, Houston, TX 77204-5060, United States
| | - Shannon M Conley
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, United States
| | - Muna I Naash
- Department of Biomedical Engineering, University of Houston, Houston, TX 77204-5060, United States.
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