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Chuecos MA, Lagor WR. Liver directed adeno-associated viral vectors to treat metabolic disease. J Inherit Metab Dis 2024; 47:22-40. [PMID: 37254440 PMCID: PMC10687323 DOI: 10.1002/jimd.12637] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 05/05/2023] [Accepted: 05/25/2023] [Indexed: 06/01/2023]
Abstract
The liver is the metabolic center of the body and an ideal target for gene therapy of inherited metabolic disorders (IMDs). Adeno-associated viral (AAV) vectors can deliver transgenes to the liver with high efficiency and specificity and a favorable safety profile. Recombinant AAV vectors contain only the transgene cassette, and their payload is converted to non-integrating circular double-stranded DNA episomes, which can provide stable expression from months to years. Insights from cellular studies and preclinical animal models have provided valuable information about AAV capsid serotypes with a high liver tropism. These vectors have been applied successfully in the clinic, particularly in trials for hemophilia, resulting in the first approved liver-directed gene therapy. Lessons from ongoing clinical trials have identified key factors affecting efficacy and safety that were not readily apparent in animal models. Circumventing pre-existing neutralizing antibodies to the AAV capsid, and mitigating adaptive immune responses to transduced cells are critical to achieving therapeutic benefit. Combining the high efficiency of AAV delivery with genome editing is a promising path to achieve more precise control of gene expression. The primary safety concern for liver gene therapy with AAV continues to be the small risk of tumorigenesis from rare vector integrations. Hepatotoxicity is a key consideration in the safety of neuromuscular gene therapies which are applied at substantially higher doses. The current knowledge base and toolkit for AAV is well developed, and poised to correct some of the most severe IMDs with liver-directed gene therapy.
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Affiliation(s)
- Marcel A. Chuecos
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX USA
- Translational Biology and Molecular Medicine Program, Baylor College of Medicine, Houston, TX USA
| | - William R. Lagor
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX USA
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2
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Wang XY, Zhang WL, Zhang X, Fu YS, Wang HM, Sun QL, Li Q, Jia YL, Zhang JH, Wang TY. Combination of MAR and intron increase transgene expression of episomal vectors in CHO cells. Biotechnol J 2023; 18:e2200643. [PMID: 37551822 DOI: 10.1002/biot.202200643] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 07/22/2023] [Accepted: 08/03/2023] [Indexed: 08/09/2023]
Abstract
Previous work has shown that the EF-1α promoter of episomal vectors maintains high-level transgene expression in stably transfected Chinese hamster ovary (CHO) cells. However, the transgene expression levels need to be further increased. Here, we first incorporated matrix attachment regions (MARs), ubiquitous chromatin opening element (UCOE), stabilizing anti repressor elements 40 (STAR 40) elements into episomal vector at different sites and orientations, and systemically assessed their effects on transgene expression in transfected CHO-K1 cells. Results showed that enhanced green fluorescent protein (eGFP) expression levels increased remarkably when MAR X-29 was inserted upstream of the promoter, followed by the insertion of MAR1 downstream of the poly A, and the orientation had no significant effect. Moreover, MAR X-29 combined with human cytomegalovirus intron (hCMVI) yielded the highest transgene expression levels (4.52-fold). Transgene expression levels were not exclusively dependent on transgene copy numbers and were not related to the mRNA expression level. In addition, vector with MAR X-29+hCMVI can induce herpes simplex virus thymidine kinase (HSV-TK) protein expression, and the HSV-TK protein showed a cell-killing effect and an obvious bystander effect on HCT116 cells. In conclusion, the combination of MAR X-29 and hCMV intron can achieve high efficiency transgene expression mediated by episomal vectors in CHO-K1 cells.
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Affiliation(s)
- Xiao-Yin Wang
- School of Basic Medical Science, Xinxiang Medical University, Xinxiang, China
- International Joint Research Laboratory for Recombinant Pharmaceutical Protein Expression System of Henan, Xinxiang Medical University, Xinxiang, China
| | - Wei-Li Zhang
- School of Basic Medical Science, Xinxiang Medical University, Xinxiang, China
- Center for Medical Genetics, Nanyang Second General Hospital, Nanyang, China
| | - Xi Zhang
- College of Pharmacy, Xinxiang Medical University, Xinxiang, China
| | - Yu-Shun Fu
- School of Basic Medical Science, Xinxiang Medical University, Xinxiang, China
| | - Hao-Min Wang
- School of Basic Medical Science, Xinxiang Medical University, Xinxiang, China
| | - Qiu-Li Sun
- International Joint Research Laboratory for Recombinant Pharmaceutical Protein Expression System of Henan, Xinxiang Medical University, Xinxiang, China
| | - Qin Li
- School of Basic Medical Science, Xinxiang Medical University, Xinxiang, China
| | - Yan-Long Jia
- College of Pharmacy, Xinxiang Medical University, Xinxiang, China
| | - Jun-He Zhang
- Institutes of Health Central Plains, Xinxiang Medical University, Xinxiang, China
| | - Tian-Yun Wang
- School of Basic Medical Science, Xinxiang Medical University, Xinxiang, China
- International Joint Research Laboratory for Recombinant Pharmaceutical Protein Expression System of Henan, Xinxiang Medical University, Xinxiang, China
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3
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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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4
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Stone D, Aubert M, Jerome KR. Adeno-associated virus vectors and neurotoxicity-lessons from preclinical and human studies. Gene Ther 2023:10.1038/s41434-023-00405-1. [PMID: 37165032 DOI: 10.1038/s41434-023-00405-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 04/12/2023] [Accepted: 04/20/2023] [Indexed: 05/12/2023]
Abstract
Over 15 years after hepatotoxicity was first observed following administration of an adeno-associated virus (AAV) vector during a hemophilia B clinical trial, recent reports of treatment-associated neurotoxicity in animals and humans have brought the potential impact of AAV-associated toxicity back to prominence. In both pre-clinical studies and clinical trials, systemic AAV administration has been associated with neurotoxicity in peripheral nerve ganglia and spinal cord. Neurological signs have also been seen following direct AAV injection into the brain, both in non-human primates and in a clinical trial for late infantile Batten disease. Neurotoxic events appear variable across species, and preclinical animal studies do not fully predict clinical observations. Accumulating data suggest that AAV-associated neurotoxicity may be underdiagnosed and may differ between species in terms of frequency and/or severity. In this review, we discuss the different animal models that have been used to demonstrate AAV-associated neurotoxicity, its potential causes and consequences, and potential approaches to blunt AAV-associated neurotoxicity.
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Affiliation(s)
- Daniel Stone
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Center, Seattle, WA, USA.
| | - Martine Aubert
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Center, Seattle, WA, USA.
| | - Keith R Jerome
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Center, Seattle, WA, USA.
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, USA.
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5
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Cepleanu-Pascu IA, Stan M, Cocioba S, Stoica I. Easy method for six-fragment Golden Gate Assembly of modular vectors. Biotechniques 2023; 74:85-99. [PMID: 36691899 DOI: 10.2144/btn-2022-0041] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Efficient cloning techniques are a requirement for synthetic biology. This study provides a simplified cloning method based on Golden Gate Assembly that can be used for rapid vector construction. The building of multiple expression vectors with customizable modules is achieved in a timely manner with minimal hands-on time by removing unnecessary steps in the workflow. The authors constructed a total of 21 mammalian episomal expression vectors and conducted a fluorescence expression comparison for different regulatory region combinations post-transfection in HEK293T and HEPG2 cells. Screening revealed that using the EF-1α promoter in combination with the bovine growth hormone polyadenylation sequence seemed to perform best in the types of cells tested compared with other variants.
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Affiliation(s)
| | - Miruna Stan
- Department of Biochemistry & Molecular Biology, Faculty of Biology, University of Bucharest, Bucharest, Romania
| | | | - Ileana Stoica
- Department of Genetics, Faculty of Biology, University of Bucharest, Bucharest, Romania
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Abstract
Gene therapy is poised to revolutionize modern medicine, with seemingly unlimited potential for treating and curing genetic disorders. For otherwise incurable indications, including most inherited metabolic liver disorders, gene therapy provides a realistic therapeutic option. In this Review, we discuss gene supplementation and gene editing involving the use of recombinant adeno-associated virus (rAAV) vectors for the treatment of inherited liver diseases, including updates on several ongoing clinical trials that are producing promising results. Clinical testing has been essential in highlighting many key translational challenges associated with this transformative therapy. In particular, the interaction of a patient's immune system with the vector raises issues of safety and the duration of treatment efficacy. Furthermore, several serious adverse events after the administration of high doses of rAAVs suggest greater involvement of innate immune responses and pre-existing hepatic conditions than initially anticipated. Finally, permanent modification of the host genome associated with rAAV genome integration and gene editing raises concerns about the risk of oncogenicity that require careful evaluation. We summarize the main progress, challenges and pathways forward for gene therapy for liver diseases.
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Pupo A, Fernández A, Low SH, François A, Suárez-Amarán L, Samulski RJ. AAV vectors: The Rubik's cube of human gene therapy. Mol Ther 2022; 30:3515-3541. [PMID: 36203359 PMCID: PMC9734031 DOI: 10.1016/j.ymthe.2022.09.015] [Citation(s) in RCA: 89] [Impact Index Per Article: 44.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 09/21/2022] [Accepted: 09/23/2022] [Indexed: 12/12/2022] Open
Abstract
Defective genes account for ∼80% of the total of more than 7,000 diseases known to date. Gene therapy brings the promise of a one-time treatment option that will fix the errors in patient genetic coding. Recombinant viruses are highly efficient vehicles for in vivo gene delivery. Adeno-associated virus (AAV) vectors offer unique advantages, such as tissue tropism, specificity in transduction, eliciting of a relatively low immune responses, no incorporation into the host chromosome, and long-lasting delivered gene expression, making them the most popular viral gene delivery system in clinical trials, with three AAV-based gene therapy drugs already approved by the US Food and Drug Administration (FDA) or European Medicines Agency (EMA). Despite the success of AAV vectors, their usage in particular scenarios is still limited due to remaining challenges, such as poor transduction efficiency in certain tissues, low organ specificity, pre-existing humoral immunity to AAV capsids, and vector dose-dependent toxicity in patients. In the present review, we address the different approaches to improve AAV vectors for gene therapy with a focus on AAV capsid selection and engineering, strategies to overcome anti-AAV immune response, and vector genome design, ending with a glimpse at vector production methods and the current state of recombinant AAV (rAAV) at the clinical level.
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Affiliation(s)
- Amaury Pupo
- R&D Department, Asklepios BioPharmaceutical, Inc. (AskBio), 20 T.W. Alexander, Suite 110 RTP, Durham, NC 27709, USA
| | - Audry Fernández
- R&D Department, Asklepios BioPharmaceutical, Inc. (AskBio), 20 T.W. Alexander, Suite 110 RTP, Durham, NC 27709, USA
| | - Siew Hui Low
- R&D Department, Asklepios BioPharmaceutical, Inc. (AskBio), 20 T.W. Alexander, Suite 110 RTP, Durham, NC 27709, USA
| | - Achille François
- Viralgen. Parque Tecnológico de Guipuzkoa, Edificio Kuatro, Paseo Mikeletegui, 83, 20009 San Sebastián, Spain
| | - Lester Suárez-Amarán
- R&D Department, Asklepios BioPharmaceutical, Inc. (AskBio), 20 T.W. Alexander, Suite 110 RTP, Durham, NC 27709, USA
| | - Richard Jude Samulski
- R&D Department, Asklepios BioPharmaceutical, Inc. (AskBio), 20 T.W. Alexander, Suite 110 RTP, Durham, NC 27709, USA,Department of Pharmacology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA,Corresponding author: Richard Jude Samulski, R&D Department, Asklepios BioPharmaceutical, Inc. (AskBio), 20 T.W. Alexander, Suite 110 RTP, NC 27709, USA.
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8
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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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9
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Jäschke N, Büning H. Adeno-Associated Virus Vector Design-Moving the Adeno-Associated Virus to a Bioengineered Therapeutic Nanoparticle. Hematol Oncol Clin North Am 2022; 36:667-685. [PMID: 35778330 DOI: 10.1016/j.hoc.2022.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Although the number of market-approved gene therapies is still low, this new class of therapeutics has become an integral part of modern medicine. The success and safety of gene therapy depend on the vectors used to deliver the therapeutic material. Adeno-associated virus (AAV) vectors have emerged as the most frequently used delivery system for in vivo gene therapy. This success was achieved with first-generation vectors, using capsids derived from natural AAV serotypes. Their broad tropism, the high seroprevalence for many of the AAV serotypes in the human population, and the high vector doses needed to transduce a sufficient number of therapy-relevant target cells are challenges that are addressed by engineering the capsid and the vector genome, improving the efficacy of these biological nanoparticles.
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Affiliation(s)
- Nico Jäschke
- Institute of Experimental Hematology, Hannover Medical School, Carl-Neuberg-Str.1, Hannover 30625, Germany
| | - Hildegard Büning
- Institute of Experimental Hematology, Hannover Medical School, Carl-Neuberg-Str.1, Hannover 30625, Germany; REBIRTH Research Center for Translational Regenerative Medicine, Hannover Medical School, Carl-Neuberg-Str.1, Hannover 30625, Germany; German Center for Infection Research, Partner Site Hannover-Braunschweig.
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10
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Happi Mbakam C, Lamothe G, Tremblay JP. Therapeutic Strategies for Dystrophin Replacement in Duchenne Muscular Dystrophy. Front Med (Lausanne) 2022; 9:859930. [PMID: 35419381 PMCID: PMC8995704 DOI: 10.3389/fmed.2022.859930] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 03/01/2022] [Indexed: 12/12/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is an X-linked hereditary disease characterized by progressive muscle wasting due to modifications in the DMD gene (exon deletions, nonsense mutations, intra-exonic insertions or deletions, exon duplications, splice site defects, and deep intronic mutations) that result in a lack of functional dystrophin expression. Many therapeutic approaches have so far been attempted to induce dystrophin expression and improve the patient phenotype. In this manuscript, we describe the relevant updates for some therapeutic strategies for DMD aiming to restore dystrophin expression. We also present and analyze in vitro and in vivo ongoing experimental approaches to treat the disease.
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Affiliation(s)
- Cedric Happi Mbakam
- Centre de Recherche du CHU de Québec-Université Laval, Quebec City, QC, Canada.,Department of Molecular Medicine, Faculty of Medicine, Laval University, Quebec City, QC, Canada
| | - Gabriel Lamothe
- Centre de Recherche du CHU de Québec-Université Laval, Quebec City, QC, Canada.,Department of Molecular Medicine, Faculty of Medicine, Laval University, Quebec City, QC, Canada
| | - Jacques P Tremblay
- Centre de Recherche du CHU de Québec-Université Laval, Quebec City, QC, Canada.,Department of Molecular Medicine, Faculty of Medicine, Laval University, Quebec City, QC, Canada
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11
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Muhuri M, Levy DI, Schulz M, McCarty D, Gao G. Durability of transgene expression after rAAV gene therapy. Mol Ther 2022; 30:1364-1380. [PMID: 35283274 PMCID: PMC9077371 DOI: 10.1016/j.ymthe.2022.03.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 01/09/2022] [Accepted: 03/07/2022] [Indexed: 11/19/2022] Open
Abstract
Recombinant adeno-associated virus (rAAV) gene therapy has the potential to transform the lives of patients with certain genetic disorders by increasing or restoring function to affected tissues. Following the initial establishment of transgene expression, it is unknown how long the therapeutic effect will last, although animal and emerging human data show that expression can be maintained for more than 10 years. The durability of therapeutic response is key to long-term treatment success, especially since immune responses to rAAV vectors may prevent re-dosing with the same therapy. This review explores the non-immunological and immunological processes that may limit or improve durability and the strategies that can be used to increase the duration of the therapeutic effect.
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Affiliation(s)
- Manish Muhuri
- Horae Gene Therapy Center, 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; Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA, USA; Li Weibo Institute for Rare Diseases Research, University of Massachusetts Medical School, Worcester, MA, USA.
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12
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Manini A, Abati E, Nuredini A, Corti S, Comi GP. Adeno-Associated Virus (AAV)-Mediated Gene Therapy for Duchenne Muscular Dystrophy: The Issue of Transgene Persistence. Front Neurol 2022; 12:814174. [PMID: 35095747 PMCID: PMC8797140 DOI: 10.3389/fneur.2021.814174] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 12/14/2021] [Indexed: 12/12/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is an X-linked recessive, infancy-onset neuromuscular disorder characterized by progressive muscle weakness and atrophy, leading to delay of motor milestones, loss of autonomous ambulation, respiratory failure, cardiomyopathy, and premature death. DMD originates from mutations in the DMD gene that result in a complete absence of dystrophin. Dystrophin is a cytoskeletal protein which belongs to the dystrophin-associated protein complex, involved in cellular signaling and myofiber membrane stabilization. To date, the few available therapeutic options are aimed at lessening disease progression, but persistent loss of muscle tissue and function and premature death are unavoidable. In this scenario, one of the most promising therapeutic strategies for DMD is represented by adeno-associated virus (AAV)-mediated gene therapy. DMD gene therapy relies on the administration of exogenous micro-dystrophin, a miniature version of the dystrophin gene lacking unnecessary domains and encoding a truncated, but functional, dystrophin protein. Limited transgene persistence represents one of the most significant issues that jeopardize the translatability of DMD gene replacement strategies from the bench to the bedside. Here, we critically review preclinical and clinical studies of AAV-mediated gene therapy in DMD, focusing on long-term transgene persistence in transduced tissues, which can deeply affect effectiveness and sustainability of gene replacement in DMD. We also discuss the role played by the overactivation of the immune host system in limiting long-term expression of genetic material. In this perspective, further studies aimed at better elucidating the need for immune suppression in AAV-treated subjects are warranted in order to allow for life-long therapy in DMD patients.
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Affiliation(s)
- Arianna Manini
- Department of Pathophysiology and Transplantation (DEPT), University of Milan, Milan, Italy
| | - Elena Abati
- Department of Pathophysiology and Transplantation (DEPT), University of Milan, Milan, Italy
| | - Andi Nuredini
- Department of Pathophysiology and Transplantation (DEPT), University of Milan, Milan, Italy
| | - Stefania Corti
- Department of Pathophysiology and Transplantation (DEPT), University of Milan, Milan, Italy.,Neurology Unit, Neuroscience Section, Dino Ferrari Center, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Ospedale Maggiore Policlinico, Milan, Italy
| | - Giacomo Pietro Comi
- Department of Pathophysiology and Transplantation (DEPT), University of Milan, Milan, Italy.,Neurology Unit, Neuroscience Section, Dino Ferrari Center, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Ospedale Maggiore Policlinico, Milan, Italy
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13
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Silva-Pilipich N, Smerdou C, Vanrell L. A Small Virus to Deliver Small Antibodies: New Targeted Therapies Based on AAV Delivery of Nanobodies. Microorganisms 2021; 9:microorganisms9091956. [PMID: 34576851 PMCID: PMC8465657 DOI: 10.3390/microorganisms9091956] [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: 07/31/2021] [Revised: 09/04/2021] [Accepted: 09/07/2021] [Indexed: 12/12/2022] Open
Abstract
Nanobodies are camelid-derived single-domain antibodies that present some advantages versus conventional antibodies, such as a smaller size, and higher tissue penetrability, stability, and hydrophilicity. Although nanobodies can be delivered as proteins, in vivo expression from adeno-associated viral (AAV) vectors represents an attractive strategy. This is due to the fact that AAV vectors, that can provide long-term expression of recombinant genes, have shown an excellent safety profile, and can accommodate genes for one or several nanobodies. In fact, several studies showed that AAV vectors can provide sustained nanobody expression both locally or systemically in preclinical models of human diseases. Some of the pathologies addressed with this technology include cancer, neurological, cardiovascular, infectious, and genetic diseases. Depending on the indication, AAV-delivered nanobodies can be expressed extracellularly or inside cells. Intracellular nanobodies or “intrabodies” carry out their function by interacting with cell proteins involved in disease and have also been designed to help elucidate cellular mechanisms by interfering with normal cell processes. Finally, nanobodies can also be used to retarget AAV vectors, when tethered to viral capsid proteins. This review covers applications in which AAV vectors have been used to deliver nanobodies, with a focus on their therapeutic use.
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Affiliation(s)
- Noelia Silva-Pilipich
- Division of Gene Therapy and Regulation of Gene Expression, Cima Universidad de Navarra and Instituto de Investigación Sanitaria de Navarra (IdISNA), 31008 Pamplona, Spain;
| | - Cristian Smerdou
- Division of Gene Therapy and Regulation of Gene Expression, Cima Universidad de Navarra and Instituto de Investigación Sanitaria de Navarra (IdISNA), 31008 Pamplona, Spain;
- Correspondence: (C.S.); (L.V.); Tel.: +34-948194700 (C.S.); +508-29021505 (L.V.); Fax: +34-948194717 (C.S.)
| | - Lucía Vanrell
- Biotechnology Laboratory, Facultad de Ingeniería, Universidad ORT Uruguay, Mercedes 1237, Montevideo 11100, Uruguay
- Nanogrow Biotech, CIE BIO Incubator, Mercedes 1237, Montevideo 11100, Uruguay
- Correspondence: (C.S.); (L.V.); Tel.: +34-948194700 (C.S.); +508-29021505 (L.V.); Fax: +34-948194717 (C.S.)
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14
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Sherpa C, Le Grice SFJ. Adeno-Associated Viral Vector Mediated Expression of Broadly- Neutralizing Antibodies Against HIV-Hitting a Fast-Moving Target. Curr HIV Res 2021; 18:114-131. [PMID: 32039686 DOI: 10.2174/1570162x18666200210121339] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 01/05/2020] [Accepted: 01/16/2020] [Indexed: 12/12/2022]
Abstract
The vast genetic variability of HIV has impeded efforts towards a cure for HIV. Lifelong administration of combined antiretroviral therapy (cART) is highly effective against HIV and has markedly increased the life expectancy of HIV infected individuals. However, the long-term usage of cART is associated with co-morbidities and the emergence of multidrug-resistant escape mutants necessitating the development of alternative approaches to combat HIV/AIDS. In the past decade, the development of single-cell antibody cloning methods has facilitated the characterization of a diverse array of highly potent neutralizing antibodies against a broad range of HIV strains. Although the passive transfer of these broadly neutralizing antibodies (bnAbs) in both animal models and humans has been shown to elicit significant antiviral effects, long term virologic suppression requires repeated administration of these antibodies. Adeno-associated virus (AAV) mediated antibody gene transfer provides a long-term expression of these antibodies from a single administration of the recombinant vector. Therefore, this vectored approach holds promises in the treatment and prevention of a chronic disease like HIV infection. Here, we provide an overview of HIV genetic diversity, AAV vectorology, and anti-HIV bnAbs and summarize the promises and challenges of the application of AAV in the delivery of bnAbs for HIV prevention and therapy.
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Affiliation(s)
- Chringma Sherpa
- Basic Research Laboratory, Center for Cancer Research, National Cancer Institute, National Institute of Health, Frederick, Maryland, 21702, United States
| | - Stuart F J Le Grice
- Basic Research Laboratory, Center for Cancer Research, National Cancer Institute, National Institute of Health, Frederick, Maryland, 21702, United States
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15
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Hacker UT, Bentler M, Kaniowska D, Morgan M, Büning H. Towards Clinical Implementation of Adeno-Associated Virus (AAV) Vectors for Cancer Gene Therapy: Current Status and Future Perspectives. Cancers (Basel) 2020; 12:E1889. [PMID: 32674264 PMCID: PMC7409174 DOI: 10.3390/cancers12071889] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 07/03/2020] [Accepted: 07/07/2020] [Indexed: 02/06/2023] Open
Abstract
Adeno-associated virus (AAV) vectors have gained tremendous attention as in vivo delivery systems in gene therapy for inherited monogenetic diseases. First market approvals, excellent safety data, availability of large-scale production protocols, and the possibility to tailor the vector towards optimized and cell-type specific gene transfer offers to move from (ultra) rare to common diseases. Cancer, a major health burden for which novel therapeutic options are urgently needed, represents such a target. We here provide an up-to-date overview of the strategies which are currently developed for the use of AAV vectors in cancer gene therapy and discuss the perspectives for the future translation of these pre-clinical approaches into the clinic.
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Affiliation(s)
- Ulrich T. Hacker
- Department of Oncology, Gastroenterology, Hepatology, Pulmonology, and Infectious Diseases, University Cancer Center Leipzig (UCCL), Leipzig University Medical Center, 04103 Leipzig, Germany;
- Institute of Experimental Hematology, Hannover Medical School, 30625 Hannover, Germany; (M.B.); (M.M.)
| | - Martin Bentler
- Institute of Experimental Hematology, Hannover Medical School, 30625 Hannover, Germany; (M.B.); (M.M.)
| | - Dorota Kaniowska
- Department of Oncology, Gastroenterology, Hepatology, Pulmonology, and Infectious Diseases, University Cancer Center Leipzig (UCCL), Leipzig University Medical Center, 04103 Leipzig, Germany;
| | - Michael Morgan
- Institute of Experimental Hematology, Hannover Medical School, 30625 Hannover, Germany; (M.B.); (M.M.)
- REBIRTH Research Center for Translational Regenerative Medicine, Hannover Medical School, 30625 Hannover, Germany
| | - Hildegard Büning
- Institute of Experimental Hematology, Hannover Medical School, 30625 Hannover, Germany; (M.B.); (M.M.)
- REBIRTH Research Center for Translational Regenerative Medicine, Hannover Medical School, 30625 Hannover, Germany
- German Center for Infection Research (DZIF), Partner Site Hannover-Braunschweig, Inhoffenstraße 7, 38124 Braunschweig, Germany
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16
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Chen SH, Papaneri A, Walker M, Scappini E, Keys RD, Martin NP. A Simple, Two-Step, Small-Scale Purification of Recombinant Adeno-Associated Viruses. J Virol Methods 2020; 281:113863. [PMID: 32371233 DOI: 10.1016/j.jviromet.2020.113863] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 02/22/2020] [Accepted: 04/03/2020] [Indexed: 10/24/2022]
Abstract
Recombinant adeno-associated viruses (rAAVs) are robust and versatile tools for in vivo gene delivery. Natural and designer capsid variations in rAAVs allow for targeted gene delivery to specific cell types. Low immunogenicity and lack of pathogenesis also add to the popularity of this virus as an innocuous gene delivery vector for gene therapy. rAAVs are routinely used to express recombinases, sensors, detectors, CRISPR-Cas9 components, or to simply overexpress a gene of interest for functional studies. High production demand has given rise to multiple platforms for the production and purification of rAAVs. However, most platforms rely heavily on large amounts of starting material and multiple purification steps to produce highly purified viral particles. Often, researchers require several small-scale purified rAAVs. Here, we describe a simple and efficient technique for purification of recombinant rAAVs from small amounts of starting material in a two-step purification method. In this method, rAAVs are released into the packaging cell medium using high salt concentration, pelleted by ultracentrifugation to remove soluble impurities. Then, the resuspended pellet is purified using a protein spin-concentrator. In this protocol, we modify the conventional rAAV purification methods to eliminate the need for fraction collection and the labor-intensive steps for evaluating the titer and purity of individual fractions. The resulting rAAV preparations are comparable in titer and purity to commercially available samples. This simplified process can be used to generate highly purified rAAV particles on a small scale, thereby saving resources, generating less waste, and reducing a laboratory's environmental footprint.
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Affiliation(s)
- Shih-Heng Chen
- Neurobiology Laboratory, U.S.A; Viral Vector Core, U.S.A
| | | | - Mitzie Walker
- Neurobiology Laboratory, U.S.A; Viral Vector Core, U.S.A
| | | | - Robert D Keys
- Cellular and Molecular Pathology Branch, National Institute of Environmental Health Sciences, NIH/DHHS, 111 T.W. Alexander Drive, Research Triangle Park, N.C. 27709, U.S.A
| | - Negin P Martin
- Neurobiology Laboratory, U.S.A; Viral Vector Core, U.S.A.
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17
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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: 1172] [Impact Index Per Article: 234.4] [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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18
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Wang XY, Zhang X, Wang TY, Jia YL, Xu DH, Yi DD. Shortened nuclear matrix attachment regions are sufficient for replication and maintenance of episomes in mammalian cells. Mol Biol Cell 2019; 30:2761-2770. [PMID: 31509492 PMCID: PMC6789156 DOI: 10.1091/mbc.e19-02-0108] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Matrix attachment regions (MARs) can mediate the replication of vector episomes in mammalian cells; however, the molecular mode of action remains unclear. Here, we assessed the characteristics of MARs and the mechanism that mediates episomal vector replication in mammalian cells. Five shortened subfragments of β-interferon MAR fragments were cloned and transferred into CHO cells, and transgene expression levels, presence of the gene, and the episomal maintenance mechanism were determined. Three shortened MAR derivatives (position 781–1320, 1201–1740, and 1621–2201) retained full MAR activity and mediated episomal vector replication. Moreover, the three shortened MARs showed higher transgene expression levels, greater efficiency in colony formation, and more persistent transgene expression compared with those of the original pEPI-1 plasmid, and three functional truncated MARs can bind to SAF-A MAR-binding protein. These results suggest that shortened MARs are sufficient for replication and maintenance of episomes in CHO cells.
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Affiliation(s)
- Xiao-Yin Wang
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang 453003, Henan, China.,International Joint Research Laboratory for Recombiant Pharmaceutical Protein Expression System of Henan, Xinxiang Medical University, Xinxiang 453003, Henan, China
| | - Xi Zhang
- International Joint Research Laboratory for Recombiant Pharmaceutical Protein Expression System of Henan, Xinxiang Medical University, Xinxiang 453003, Henan, China
| | - Tian-Yun Wang
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang 453003, Henan, China.,International Joint Research Laboratory for Recombiant Pharmaceutical Protein Expression System of Henan, Xinxiang Medical University, Xinxiang 453003, Henan, China
| | - Yan-Long Jia
- Pharmacy Collage, Xinxiang Medical University, Xinxiang 453003, Henan, China
| | - Dan-Hua Xu
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang 453003, Henan, China.,International Joint Research Laboratory for Recombiant Pharmaceutical Protein Expression System of Henan, Xinxiang Medical University, Xinxiang 453003, Henan, China
| | - Dan-Dan Yi
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang 453003, Henan, China.,International Joint Research Laboratory for Recombiant Pharmaceutical Protein Expression System of Henan, Xinxiang Medical University, Xinxiang 453003, Henan, China
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19
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Wang XY, Yi DD, Wang TY, Wu YF, Chai YR, Xu DH, Zhao CP, Song C. Enhancing expression level and stability of transgene mediated by episomal vector via buffering DNA methyltransferase in transfected CHO cells. J Cell Biochem 2019; 120:15661-15670. [PMID: 31074065 DOI: 10.1002/jcb.28835] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 02/01/2019] [Accepted: 02/04/2019] [Indexed: 12/17/2022]
Abstract
Nonviral episomal vectors present attractive alternative vehicles for gene therapy applications. Previously, we have established a new type of nonviral episomal vector-mediated by the characteristic motifs of matrix attachment regions (MARs), which is driven by the cytomegalovirus (CMV) promoter. However, the CMV promoter is intrinsically susceptible to silencing, resulting in declined productivity during long-term culture. In this study, Chinese hamster ovary (CHO) cells and DNA methyltransferase-deficient (Dnmt3a-deficient) CHO cells were transfected with plasmid-mediated by MAR, or CHO cells were treated with the DNA methylation inhibitor 5-Aza-2'-deoxycytidine. Flow cytometry, plasmid rescue experiments, fluorescence in-situ hybridization (FISH), and bisulfite sequencing were performed to observe transgene expression, its state of existence, and the CpG methylation level of the CMV promoter. The results indicated that all DNA methylation inhibitor and methyltransferase deficient cells could increase transgene expression levels and stability in the presence or absence of selection pressure after a 60-generation culture. Plasmid rescue assay and FISH analysis showed that the vector still existed episomally after long-time culture. Moreover, a relatively lower CMV promoter methylation level was observed in Dnmt3a-deficient cell lines and CHO cells treated with 5-Aza-2'-deoxycytidine. In addition, Dnmt3a-deficient cells were superior to the DNA methylation inhibitor treatment regarding the transgene expression and long-term stability. Our study provides the first evidence that lower DNA methyltransferase can enhance expression level and stability of transgenes mediated by episomal vectors in transfected CHO cells.
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Affiliation(s)
- Xiao-Yin Wang
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, Henan, China.,International Joint Research Laboratory for Recombiant Pharmaceutical Protein Expression System of Henan, Xinxiang Medical University, Xinxiang, Henan, China
| | - Dan-Dan Yi
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, Henan, China
| | - Tian-Yun Wang
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, Henan, China.,International Joint Research Laboratory for Recombiant Pharmaceutical Protein Expression System of Henan, Xinxiang Medical University, Xinxiang, Henan, China
| | - Yan-Fang Wu
- Department of Pharmacy, Medical College, Henan University of Science and Technology, Luoyang, China
| | - Yu-Rong Chai
- Department of Histology and Embryology, School of Basic Medical Sciences, University of Zhengzhou, Zhengzhou, Henan, China
| | - Dan-Hua Xu
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, Henan, China
| | - Chun-Peng Zhao
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang, Henan, China
| | - Chao Song
- International Joint Research Laboratory for Recombiant Pharmaceutical Protein Expression System of Henan, Xinxiang Medical University, Xinxiang, Henan, China
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20
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Nagree MS, Scalia S, McKillop WM, Medin JA. An update on gene therapy for lysosomal storage disorders. Expert Opin Biol Ther 2019; 19:655-670. [DOI: 10.1080/14712598.2019.1607837] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Murtaza S. Nagree
- Department of Medical Biophysics, University of Toronto, Toronto,
Ontario, Canada
- Department of Pediatrics, Medical College of Wisconsin, Milwaukee,
WI, USA
| | - Simone Scalia
- Department of Pediatrics, Medical College of Wisconsin, Milwaukee,
WI, USA
| | | | - Jeffrey A. Medin
- Department of Medical Biophysics, University of Toronto, Toronto,
Ontario, Canada
- Department of Pediatrics, Medical College of Wisconsin, Milwaukee,
WI, USA
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee,
WI, USA
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21
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Stanimirovic DB, Sandhu JK, Costain WJ. Emerging Technologies for Delivery of Biotherapeutics and Gene Therapy Across the Blood-Brain Barrier. BioDrugs 2019; 32:547-559. [PMID: 30306341 PMCID: PMC6290705 DOI: 10.1007/s40259-018-0309-y] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Antibody, immuno- and gene therapies developed for neurological indications face a delivery challenge posed by various anatomical and physiological barriers within the central nervous system (CNS); most notably, the blood–brain barrier (BBB). Emerging delivery technologies for biotherapeutics have focused on trans-cellular pathways across the BBB utilizing receptor-mediated transcytosis (RMT). ‘Traditionally’ targeted RMT receptors, transferrin receptor (TfR) and insulin receptor (IR), are ubiquitously expressed and pose numerous translational challenges during development, including species differences and safety risks. Recent advances in antibody engineering technologies and discoveries of RMT targets and BBB-crossing antibodies that are more BBB-selective have combined to create a new preclinical pipeline of BBB-crossing biotherapeutics with improved efficacy and safety. Novel BBB-selective RMT targets and carrier antibodies have exposed additional opportunities for re-targeting gene delivery vectors or nanocarriers for more efficient brain delivery. Emergence and refinement of core technologies of genetic engineering and editing as well as biomanufacturing of viral vectors and cell-derived products have de-risked the path to the development of systemic gene therapy approaches for the CNS. In particular, brain-tropic viral vectors and extracellular vesicles have recently expanded the repertoire of brain delivery strategies for biotherapeutics. Whereas protein biotherapeutics and bispecific antibodies enabled for BBB transcytosis are rapidly heading towards clinical trials, systemic gene therapy approaches for CNS will likely remain in research phase for the foreseeable future. The promise and limitations of these emerging cross-BBB delivery technologies are further discussed in this article.
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Affiliation(s)
- Danica B Stanimirovic
- Human Health Therapeutics Research Centre, Translational Bioscience, National Research Council Canada, 1200 Montreal Road, Ottawa, ON, Canada.
| | - Jagdeep K Sandhu
- Human Health Therapeutics Research Centre, Translational Bioscience, National Research Council Canada, 1200 Montreal Road, Ottawa, ON, Canada
| | - Will J Costain
- Human Health Therapeutics Research Centre, Translational Bioscience, National Research Council Canada, 1200 Montreal Road, Ottawa, ON, Canada
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22
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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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23
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Lee EJ, Guenther CM, Suh J. Adeno-Associated Virus (AAV) Vectors: Rational Design Strategies for Capsid Engineering. CURRENT OPINION IN BIOMEDICAL ENGINEERING 2018; 7:58-63. [PMID: 31106283 DOI: 10.1016/j.cobme.2018.09.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Adeno-associated virus (AAV) consists of a simple genome, infects mammalian cells, displays nonpathogenicity in humans, and spans an array of serotypes and variants bearing distinct tissue tropisms. These attributes lend AAV tremendous promise as a gene delivery vector, further substantiated by its extensive testing in human clinical trials. Rational design approaches to capsid engineering leverage current scientific knowledge of AAV to further modulate, enhance and optimize the performance of the vectors. Capsid modification strategies include amino acid point mutations, peptide domain insertions, and chemical biology approaches. Through such efforts, insights regarding AAV capsid sequence-structure-function relationships can be learned. Developments over the last 5 years in rational design-based capsid engineering approaches will be presented and discussed.
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Affiliation(s)
- Esther J Lee
- Department of Bioengineering, Rice University, 6500 Main St., MS-142, Houston, TX 77030, USA
| | - Caitlin M Guenther
- Department of Bioengineering, Rice University, 6500 Main St., MS-142, Houston, TX 77030, USA
| | - Junghae Suh
- Department of Bioengineering, Rice University, 6500 Main St., MS-142, Houston, TX 77030, USA
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24
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Aguti S, Malerba A, Zhou H. The progress of AAV-mediated gene therapy in neuromuscular disorders. Expert Opin Biol Ther 2018; 18:681-693. [DOI: 10.1080/14712598.2018.1479739] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Sara Aguti
- The Dubowitz Neuromuscular Centre, Developmental Neurosciences Programme, Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Alberto Malerba
- School of Biological Sciences, Royal Holloway, University of London, Egham, Surrey, UK
| | - Haiyan Zhou
- The Dubowitz Neuromuscular Centre, Developmental Neurosciences Programme, Great Ormond Street Institute of Child Health, University College London, London, UK
- Genetics and Genomic Medicine Programme, Great Ormond Street Institute of Child Health, University College London, London, UK
- NIHR Great Ormond Street Hospital Biomedical Research Centre, London, UK
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