1
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Catalán-Tatjer D, Tzimou K, Nielsen LK, Lavado-García J. Unravelling the essential elements for recombinant adeno-associated virus (rAAV) production in animal cell-based platforms. Biotechnol Adv 2024; 73:108370. [PMID: 38692443 DOI: 10.1016/j.biotechadv.2024.108370] [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: 01/16/2024] [Revised: 04/05/2024] [Accepted: 04/27/2024] [Indexed: 05/03/2024]
Abstract
Recombinant adeno-associated viruses (rAAVs) stand at the forefront of gene therapy applications, holding immense significance for their safe and efficient gene delivery capabilities. The constantly increasing and unmet demand for rAAVs underscores the need for a more comprehensive understanding of AAV biology and its impact on rAAV production. In this literature review, we delved into AAV biology and rAAV manufacturing bioprocesses, unravelling the functions and essentiality of proteins involved in rAAV production. We discuss the interconnections between these proteins and how they affect the choice of rAAV production platform. By addressing existing inconsistencies, literature gaps and limitations, this review aims to define a minimal set of genes that are essential for rAAV production, providing the potential to advance rAAV biomanufacturing, with a focus on minimizing the genetic load within rAAV-producing cells.
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Affiliation(s)
- David Catalán-Tatjer
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Denmark
| | - Konstantina Tzimou
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Denmark
| | - Lars K Nielsen
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Denmark; Australian Institute for Bioengineering and Nanotechnology, University of Queensland, Australia
| | - Jesús Lavado-García
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Denmark.
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2
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Merten OW. Development of Stable Packaging and Producer Cell Lines for the Production of AAV Vectors. Microorganisms 2024; 12:384. [PMID: 38399788 PMCID: PMC10892526 DOI: 10.3390/microorganisms12020384] [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: 12/04/2023] [Revised: 01/22/2024] [Accepted: 02/08/2024] [Indexed: 02/25/2024] Open
Abstract
Today, recombinant adeno-associated virus (rAAV) vectors represent the vector systems which are mostly used for in vivo gene therapy for the treatment of rare and less-rare diseases. Although most of the past developments have been performed by using a transfection-based method and more than half of the authorized rAAV-based treatments are based on transfection process, the tendency is towards the use of stable inducible packaging and producer cell lines because their use is much more straightforward and leads in parallel to reduction in the overall manufacturing costs. This article presents the development of HeLa cell-based packaging/producer cell lines up to their use for large-scale rAAV vector production, the more recent development of HEK293-based packaging and producer cell lines, as well as of packaging cell lines based on the use of Sf9 cells. The production features are presented in brief (where available), including vector titer, specific productivity, and full-to-empty particle ratio.
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3
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Onishi T, Nonaka M, Maruno T, Yamaguchi Y, Fukuhara M, Torisu T, Maeda M, Abbatiello S, Haris A, Richardson K, Giles K, Preece S, Yamano-Adachi N, Omasa T, Uchiyama S. Enhancement of recombinant adeno-associated virus activity by improved stoichiometry and homogeneity of capsid protein assembly. Mol Ther Methods Clin Dev 2023; 31:101142. [PMID: 38027055 PMCID: PMC10663676 DOI: 10.1016/j.omtm.2023.101142] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 10/21/2023] [Indexed: 12/01/2023]
Abstract
Studies of recombinant adeno-associated virus (rAAV) revealed the mixture of full particles with different densities in rAAV. There are no conclusive results because of the lack of quantitative stoichiometric viral proteins, encapsidated DNA, and particle level analyses. We report the first comprehensive characterization of low- and high-density rAAV serotype 2 particles. Capillary gel electrophoresis showed high-density particles possessing a designed DNA encapsidated in the capsid composed of (VP1 + VP2)/VP3 = 0.27, whereas low-density particles have the same DNA but with a different capsid composition of (VP1 + VP2)/VP3 = 0.31, supported by sedimentation velocity-analytical ultracentrifugation and charge detection-mass spectrometry. In vitro analysis demonstrated that the low-density particles had 8.9% higher transduction efficacy than that of the particles before fractionation. Further, based on our recent findings of VP3 clip, we created rAAV2 single amino acid variants of the transcription start methionine of VP3 (M203V) and VP3 clip (M211V). The rAAV2-M203V variant had homogeneous particles with higher (VP1+VP2)/VP3 values (0.35) and demonstrated 24.7% higher transduction efficacy compared with the wild type. This study successfully provided highly functional rAAV by the extensive fractionation from the mixture of rAAV2 full particles or by the single amino acid replacement.
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Affiliation(s)
- Takayuki Onishi
- Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Michika Nonaka
- Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Takahiro Maruno
- Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
- U-Medico Inc, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Yuki Yamaguchi
- Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Mitsuko Fukuhara
- Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
- U-Medico Inc, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Tetsuo Torisu
- Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Masaharu Maeda
- Osaka Consolidated Laboratory, Manufacturing Technology Association of Biologics, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | | | | | - Keith Richardson
- Waters Corporation (Micromass UK Ltd), Stamford Avenue, Altrincham Road, Wilmslow SK9 4AX, UK
| | | | - Steve Preece
- Waters Corporation (Micromass UK Ltd), Stamford Avenue, Altrincham Road, Wilmslow SK9 4AX, UK
| | - Noriko Yamano-Adachi
- Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Takeshi Omasa
- Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Susumu Uchiyama
- Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
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4
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Nagy A, Chakrabarti L, Kurasawa J, Mulagapati SHR, Devine P, Therres J, Chen Z, Schmelzer AE. Engineered CHO cells as a novel AAV production platform for gene therapy delivery. Sci Rep 2023; 13:19210. [PMID: 37932360 PMCID: PMC10628118 DOI: 10.1038/s41598-023-46298-3] [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] [Received: 09/11/2023] [Accepted: 10/30/2023] [Indexed: 11/08/2023] Open
Abstract
The Herpes simplex virus (HSV)-based platform for production of recombinant adeno-associated viral vectors (rAAVs) yields higher titers and increased percentage of full capsids when compared to the triple transient transfection (TTT) method. However, this platform currently faces two major challenges. The first challenge is the reliance on commercial media, sometimes supplemented with serum, leading to costly manufacturing and a high risk for introduction of adventitious agents. The second challenge is that the production of HSV-1 relies on adherent complementing Vero cells (V27), making it difficult to scale up. We engineered serum-free-adapted CHO cells expressing key HSV-1 entry receptors, HVEM and/or Nectin-1 to address the first challenge. Using high-throughput cloning methods, we successfully selected a HVEM receptor-expressing clone (CHO-HV-C1) that yields 1.62 × 109, 2.51 × 109, and 4.07 × 109 viral genome copies/mL with rAAV6.2-GFP, rAAV8-GFP, and rAAV9-GFP vectors respectively, within 24 h post rHSV-1 co-infection. Moreover, CHO-HV-C1-derived rAAVs had comparable in vitro transduction, infectivity, and biodistribution titers to those produced by TTT. The second challenge was addressed via engineering CHO-HV-C1 cells to express HSV-1 CP27. These cells successfully produced rHSV-1 vectors, but with significantly lower titers than V27 cells. Taken together, the CHO/HSV system provides a novel, scalable, reduced cost, serum-free AAV manufacturing platform.
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Affiliation(s)
- Abdou Nagy
- Cell Culture and Fermentation Sciences, Biopharmaceutical Development, BioPharmaceuticals R&D, AstraZeneca, One MedImmune Way, Gaithersburg, MD, 20878, USA.
| | - Lina Chakrabarti
- Cell Culture and Fermentation Sciences, Biopharmaceutical Development, BioPharmaceuticals R&D, AstraZeneca, One MedImmune Way, Gaithersburg, MD, 20878, USA
| | - James Kurasawa
- Biologics Engineering, R&D, AstraZeneca, One MedImmune Way, Gaithersburg, MD, 20878, USA
| | - Sri Hari Raju Mulagapati
- Analytical Science, Biopharmaceutical Development, Biopharma R&D, AstraZeneca, One MedImmune Way, Gaithersburg, MD, 20878, USA
| | - Paul Devine
- Analytical Science, Biopharmaceutical Development, Biopharma R&D, AstraZeneca, Milstein Building, Granta Park, Cambridge, CB216GH, UK
| | - Jamy Therres
- Cell Culture and Fermentation Sciences, Biopharmaceutical Development, BioPharmaceuticals R&D, AstraZeneca, One MedImmune Way, Gaithersburg, MD, 20878, USA
| | - Zhongying Chen
- Clinical Pharmacology and Safety Sciences, AstraZeneca, One MedImmune Way, Gaithersburg, MD, 20878, USA
| | - Albert E Schmelzer
- Cell Culture and Fermentation Sciences, Biopharmaceutical Development, BioPharmaceuticals R&D, AstraZeneca, One MedImmune Way, Gaithersburg, MD, 20878, USA.
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5
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Brimble MA, Winston SM, Davidoff AM. Stowaways in the cargo: Contaminating nucleic acids in rAAV preparations for gene therapy. Mol Ther 2023; 31:2826-2838. [PMID: 37533254 PMCID: PMC10556190 DOI: 10.1016/j.ymthe.2023.07.025] [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: 04/29/2023] [Revised: 07/11/2023] [Accepted: 07/31/2023] [Indexed: 08/04/2023] Open
Abstract
Recombinant AAV (rAAV) is the most used delivery vector for clinical gene therapy. However, many issues must be addressed before safer and more widespread implementation can be achieved. At present, efficacies are highly variable across trials and patients, and immune responses after treatment are widely reported. Although rAAV is capable of directly delivering gene-encoded therapeutic sequences, increased scrutiny of viral preparations for translational use have revealed contaminating nucleic acid species packaged within rAAV preparations. The introduction of non-therapeutic nucleic acids into a recipient patient adds to the risk burden, immunogenic or otherwise, of rAAV therapies. DNA from incomplete expression cassettes, portions of plasmids or vectors used to facilitate viral replication, and production cell line genomes all have the potential to be packaged within rAAV. Here, we review what is currently known about the profile, abundance, and post-treatment consequences of nucleic acid impurities within rAAV and cover strategies that have been developed to improve rAAV purity. Furthering our understanding of these aberrantly packaged DNA species will help to ensure the continued safe implementation of rAAV therapies as the number of patients treated with this modality increases.
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Affiliation(s)
- Mark A Brimble
- Department of Immunology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA.
| | - Stephen M Winston
- Department of Surgery, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA; St. Jude Children's Research Hospital Graduate School of Biomedical Sciences, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Andrew M Davidoff
- Department of Surgery, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
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6
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Kondratov O, Zolotukhin S. Exploring the Comprehensive Kozak Sequence Landscape for AAV Production in Sf9 System. Viruses 2023; 15:1983. [PMID: 37896760 PMCID: PMC10612025 DOI: 10.3390/v15101983] [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: 08/17/2023] [Revised: 09/10/2023] [Accepted: 09/20/2023] [Indexed: 10/29/2023] Open
Abstract
The widespread successful use of recombinant Adeno-associated virus (rAAV) in gene therapy has driven the demand for scale-up manufacturing methods of vectors with optimized yield and transduction efficiency. The Baculovirus/Sf9 system is a promising platform for high yield production; however, a major drawback to using an invertebrate cell line compared to a mammalian system is a generally altered AAV capsid stoichiometry resulting in lower biological potency. Here, we introduce a term of the structural and biological "fitness" of an AAV capsid as a function of two interdependent parameters: (1) packaging efficiency (yield), and (2) transduction efficiency (infectivity). Both parameters are critically dependent on AAV capsid structural proteins VP1/2/3 stoichiometry. To identify an optimal AAV capsid composition, we developed a novel Directed Evolution (DE) protocol for assessing the structural and biological fitness of Sf9-manufactured rAAV for any given serotype. The approach involves the packaging of a combinatorial capsid library in insect Sf9 cells, followed by a library screening for high infectivity in human Cre-recombinase-expressing C12 cells. One single DE selection round, complemented by Next-Generation Sequencing (NGS) and guided by in silico analysis, identifies a small subset of VP1 translation initiation sites (known as Kozak sequence) encoding "fit" AAV capsids characterized by a high production yield and superior transduction efficiencies.
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Affiliation(s)
- Oleksandr Kondratov
- Division of Cellular and Molecular Therapy, Department of Pediatrics, College of Medicine, University of Florida, Gainesville, FL 32610, USA;
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7
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Fu Q, Polanco A, Lee YS, Yoon S. Critical challenges and advances in recombinant adeno-associated virus (rAAV) biomanufacturing. Biotechnol Bioeng 2023; 120:2601-2621. [PMID: 37126355 DOI: 10.1002/bit.28412] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 03/27/2023] [Accepted: 04/19/2023] [Indexed: 05/02/2023]
Abstract
Gene therapy is a promising therapeutic approach for genetic and acquired diseases nowadays. Among DNA delivery vectors, recombinant adeno-associated virus (rAAV) is one of the most effective and safest vectors used in commercial drugs and clinical trials. However, the current yield of rAAV biomanufacturing lags behind the necessary dosages for clinical and commercial use, which embodies a concentrated reflection of low productivity of rAAV from host cells, difficult scalability of the rAAV-producing bioprocess, and high levels of impurities materialized during production. Those issues directly impact the price of gene therapy medicine in the market, limiting most patients' access to gene therapy. In this context, the current practices and several critical challenges associated with rAAV gene therapy bioprocesses are reviewed, followed by a discussion of recent advances in rAAV-mediated gene therapy and other therapeutic biological fields that could improve biomanufacturing if these advances are integrated effectively into the current systems. This review aims to provide the current state-of-the-art technology and perspectives to enhance the productivity of rAAV while reducing impurities during production of rAAV.
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Affiliation(s)
- Qiang Fu
- Department of Biomedical Engineering and Biotechnology, The University of Massachusetts Lowell, Lowell, Massachusetts, USA
| | - Ashli Polanco
- Department of Chemical Engineering, The University of Massachusetts Lowell, Lowell, Massachusetts, USA
| | - Yong Suk Lee
- Department of Pharmaceutical Sciences, The University of Massachusetts Lowell, Lowell, Massachusetts, USA
| | - Seongkyu Yoon
- Department of Chemical Engineering, The University of Massachusetts Lowell, Lowell, Massachusetts, USA
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8
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Large EE, Chapman MS. Adeno-associated virus receptor complexes and implications for adeno-associated virus immune neutralization. Front Microbiol 2023; 14:1116896. [PMID: 36846761 PMCID: PMC9950413 DOI: 10.3389/fmicb.2023.1116896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 01/20/2023] [Indexed: 02/12/2023] Open
Abstract
Adeno-associated viruses (AAV) are among the foremost vectors for in vivo gene therapy. A number of monoclonal antibodies against several serotypes of AAV have previously been prepared. Many are neutralizing, and the predominant mechanisms have been reported as the inhibition of binding to extracellular glycan receptors or interference with some post-entry step. The identification of a protein receptor and recent structural characterization of its interactions with AAV compel reconsideration of this tenet. AAVs can be divided into two families based on which domain of the receptor is strongly bound. Neighboring domains, unseen in the high-resolution electron microscopy structures have now been located by electron tomography, pointing away from the virus. The epitopes of neutralizing antibodies, previously characterized, are now compared to the distinct protein receptor footprints of the two families of AAV. Comparative structural analysis suggests that antibody interference with protein receptor binding might be the more prevalent mechanism than interference with glycan attachment. Limited competitive binding assays give some support to the hypothesis that inhibition of binding to the protein receptor has been an overlooked mechanism of neutralization. More extensive testing is warranted.
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Affiliation(s)
| | - Michael S. Chapman
- Department of Biochemistry, University of Missouri, Columbia, MO, United States
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9
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Pidre ML, Arrías PN, Amorós Morales LC, Romanowski V. The Magic Staff: A Comprehensive Overview of Baculovirus-Based Technologies Applied to Human and Animal Health. Viruses 2022; 15:80. [PMID: 36680120 PMCID: PMC9863858 DOI: 10.3390/v15010080] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 12/19/2022] [Accepted: 12/23/2022] [Indexed: 12/29/2022] Open
Abstract
Baculoviruses are enveloped, insect-specific viruses with large double-stranded DNA genomes. Among all the baculovirus species, Autographa californica multiple nucleopolyhedrovirus (AcMNPV) is the most studied. Due to its characteristics regarding biosafety, narrow host range and the availability of different platforms for modifying its genome, AcMNPV has become a powerful biotechnological tool. In this review, we will address the most widespread technological applications of baculoviruses. We will begin by summarizing their natural cycle both in larvae and in cell culture and how it can be exploited. Secondly, we will explore the different baculovirus-based protein expression systems (BEVS) and their multiple applications in the pharmaceutical and biotechnological industry. We will focus particularly on the production of vaccines, many of which are either currently commercialized or in advanced stages of development (e.g., Novavax, COVID-19 vaccine). In addition, recombinant baculoviruses can be used as efficient gene transduction and protein expression vectors in vertebrate cells (e.g., BacMam). Finally, we will extensively describe various gene therapy strategies based on baculoviruses applied to the treatment of different diseases. The main objective of this work is to provide an extensive up-to-date summary of the different biotechnological applications of baculoviruses, emphasizing the genetic modification strategies used in each field.
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Affiliation(s)
| | | | | | - Víctor Romanowski
- Instituto de Biotecnología y Biología Molecular (IBBM), Universidad Nacional de La Plata (UNLP) and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), La Plata 1900, Argentina
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10
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Weger S. High-Level rAAV Vector Production by rAdV-Mediated Amplification of Small Amounts of Input Vector. Viruses 2022; 15:64. [PMID: 36680104 PMCID: PMC9867474 DOI: 10.3390/v15010064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/22/2022] [Accepted: 12/22/2022] [Indexed: 12/28/2022] Open
Abstract
The successful application of recombinant adeno-associated virus (rAAV) vectors for long-term transgene expression in clinical studies requires scalable production methods with genetically stable components. Due to their simple production scheme and the high viral titers achievable, first generation recombinant adenoviruses (rAdV) have long been taken into consideration as suitable tools for simultaneously providing both the helper functions and the AAV rep and cap genes for rAAV packaging. So far, however, such rAdV-rep/cap vectors have been difficult to generate and often turned out to be genetically unstable. Through ablation of cis and trans inhibitory function in the AAV-2 genome we have succeeded in establishing separate and stable rAdVs for high-level AAV serotype 2 Rep and Cap expression. These allowed rAAV-2 production at high burst sizes by simple coinfection protocols after providing the AAV-ITR flanked transgene vector genome either as rAAV-2 particles at low input concentrations or in form of an additional rAdV. With characteristics such as the ease of producing the required components, the straightforward adaption to other transgenes and the possible extension to further serotypes or capsid variants, especially the rAdV-mediated rAAV amplification system presents a very promising candidate for up-scaling to clinical grade vector preparations.
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Affiliation(s)
- Stefan Weger
- Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Clinic for Neurology with Experimental Neurology, Gene Therapy Group, Campus Benjamin Franklin, Hindenburgdamm27, 12203 Berlin, Germany
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11
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Abstract
Adeno-associated virus (AAV) has a single-stranded DNA genome encapsidated in a small icosahedrally symmetric protein shell with 60 subunits. AAV is the leading delivery vector in emerging gene therapy treatments for inherited disorders, so its structure and molecular interactions with human hosts are of intense interest. A wide array of electron microscopic approaches have been used to visualize the virus and its complexes, depending on the scientific question, technology available, and amenability of the sample. Approaches range from subvolume tomographic analyses of complexes with large and flexible host proteins to detailed analysis of atomic interactions within the virus and with small ligands at resolutions as high as 1.6 Å. Analyses have led to the reclassification of glycan receptors as attachment factors, to structures with a new-found receptor protein, to identification of the epitopes of antibodies, and a new understanding of possible neutralization mechanisms. AAV is now well-enough characterized that it has also become a model system for EM methods development. Heralding a new era, cryo-EM is now also being deployed as an analytic tool in the process development and production quality control of high value pharmaceutical biologics, namely AAV vectors.
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Affiliation(s)
- Scott
M. Stagg
- Department
of Biological Sciences, Florida State University, Tallahassee, Florida 32306, United States
- Institute
of Molecular Biophysics, Florida State University, Tallahassee, Florida 32306, United States
| | - Craig Yoshioka
- Department
of Biomedical Engineering, Oregon Health
& Science University, Portland Oregon 97239, United States
| | - Omar Davulcu
- Environmental
Molecular Sciences Laboratory, Pacific Northwest
National Laboratory, 3335 Innovation Boulevard, Richland, Washington 99354, United States
| | - Michael S. Chapman
- Department
of Biochemistry, University of Missouri, Columbia, Missouri 65211, United States
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12
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Wörner TP, Snijder J, Friese O, Powers T, Heck AJ. Assessment of genome packaging in AAVs using Orbitrap-based charge-detection mass spectrometry. Mol Ther Methods Clin Dev 2022; 24:40-47. [PMID: 34977271 PMCID: PMC8671526 DOI: 10.1016/j.omtm.2021.11.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 11/27/2021] [Indexed: 12/31/2022]
Abstract
Adeno-associated viruses (AAVs) represent important gene therapy vectors with several approved clinical applications and numerous more in clinical trials. Genome packaging is an essential step in the bioprocessing of AAVs and needs to be tightly monitored to ensure the proper delivery of transgenes and the production of effective drugs. Current methods to monitor genome packaging have limited sensitivity, a high demand on labor, and struggle to distinguish between packaging of the intended genome or unwanted side-products. Here we show that Orbitrap-based charge-detection mass spectrometry allows the very sensitive quantification of all these different AAV bioprocessing products. A protocol is presented that allows the quantification of genome-packed AAV preparations in under half an hour, requiring only micro-liter quantities of typical AAV preparations with ∼1013 viral capsids per milliliter. The method quickly assesses the integrity and amount of genome packed AAV particles to support AAV bioprocessing and characterization of this rapidly emerging class of advanced drug therapies.
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Affiliation(s)
- Tobias P. Wörner
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Padualaan 8, 3584 CH Utrecht, the Netherlands
- Netherlands Proteomics Center, Padualaan 8, 3584 CH Utrecht, the Netherlands
| | - Joost Snijder
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Padualaan 8, 3584 CH Utrecht, the Netherlands
- Netherlands Proteomics Center, Padualaan 8, 3584 CH Utrecht, the Netherlands
| | - Olga Friese
- Biotherapeutics Pharmaceutical Sciences, Pfizer WRDM, St Louis, MO, USA
| | - Thomas Powers
- Biotherapeutics Pharmaceutical Sciences, Pfizer WRDM, St Louis, MO, USA
| | - Albert J.R. Heck
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Padualaan 8, 3584 CH Utrecht, the Netherlands
- Netherlands Proteomics Center, Padualaan 8, 3584 CH Utrecht, the Netherlands
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13
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Tan E, Chin CSH, Lim ZFS, Ng SK. HEK293 Cell Line as a Platform to Produce Recombinant Proteins and Viral Vectors. Front Bioeng Biotechnol 2021; 9:796991. [PMID: 34966729 PMCID: PMC8711270 DOI: 10.3389/fbioe.2021.796991] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 11/25/2021] [Indexed: 01/04/2023] Open
Abstract
Animal cell-based expression platforms enable the production of complex biomolecules such as recombinant proteins and viral vectors. Although most biotherapeutics are produced in animal cell lines, production in human cell lines is expanding. One important advantage of using human cell lines is the increased potential that the resulting biotherapeutics would carry more “human-like” post-translational modifications. Among the human cell lines, HEK293 is widely utilized due to its high transfectivity, rapid growth rate, and ability to grow in a serum-free, suspension culture. In this review, we discuss the use of HEK293 cells and its subtypes in the production of biotherapeutics. We also compare their usage against other commonly used host cell lines in each category of biotherapeutics and summarise the factors influencing the choice of host cell lines used.
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Affiliation(s)
- Evan Tan
- Bioprocessing Technology Institute, Agency for Science, Technology and Research (ASTAR), Singapore, Singapore
| | - Cara Sze Hui Chin
- Bioprocessing Technology Institute, Agency for Science, Technology and Research (ASTAR), Singapore, Singapore
| | - Zhi Feng Sherman Lim
- Bioprocessing Technology Institute, Agency for Science, Technology and Research (ASTAR), Singapore, Singapore
| | - Say Kong Ng
- Bioprocessing Technology Institute, Agency for Science, Technology and Research (ASTAR), Singapore, Singapore
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14
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Targovnik AM, Simonin JA, Mc Callum GJ, Smith I, Cuccovia Warlet FU, Nugnes MV, Miranda MV, Belaich MN. Solutions against emerging infectious and noninfectious human diseases through the application of baculovirus technologies. Appl Microbiol Biotechnol 2021; 105:8195-8226. [PMID: 34618205 PMCID: PMC8495437 DOI: 10.1007/s00253-021-11615-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 09/20/2021] [Accepted: 09/21/2021] [Indexed: 12/23/2022]
Abstract
Abstract
Baculoviruses are insect pathogens widely used as biotechnological tools in different fields of life sciences and technologies. The particular biology of these entities (biosafety viruses 1; large circular double-stranded DNA genomes, infective per se; generally of narrow host range on insect larvae; many of the latter being pests in agriculture) and the availability of molecular-biology procedures (e.g., genetic engineering to edit their genomes) and cellular resources (availability of cell lines that grow under in vitro culture conditions) have enabled the application of baculoviruses as active ingredients in pest control, as systems for the expression of recombinant proteins (Baculovirus Expression Vector Systems—BEVS) and as viral vectors for gene delivery in mammals or to display antigenic proteins (Baculoviruses applied on mammals—BacMam). Accordingly, BEVS and BacMam technologies have been introduced in academia because of their availability as commercial systems and ease of use and have also reached the human pharmaceutical industry, as incomparable tools in the development of biological products such as diagnostic kits, vaccines, protein therapies, and—though still in the conceptual stage involving animal models—gene therapies. Among all the baculovirus species, the Autographa californica multiple nucleopolyhedrovirus has been the most highly exploited in the above utilities for the human-biotechnology field. This review highlights the main achievements (in their different stages of development) of the use of BEVS and BacMam technologies for the generation of products for infectious and noninfectious human diseases. Key points • Baculoviruses can assist as biotechnological tools in human health problems. • Vaccines and diagnosis reagents produced in the baculovirus platform are described. • The use of recombinant baculovirus for gene therapy–based treatment is reviewed.
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Affiliation(s)
- Alexandra Marisa Targovnik
- Cátedra de Biotecnología, Departamento de Microbiología, Inmunología, Biotecnología y Genética, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 956, Buenos Aires, 1113, Argentina.
- Instituto de Nanobiotecnología (NANOBIOTEC), Facultad de Farmacia y Bioquímica, CONICET -Universidad de Buenos Aires, Junín 956, Sexto Piso, C1113AAD, 1113, Buenos Aires, Argentina.
| | - Jorge Alejandro Simonin
- Laboratorio de Ingeniería Genética y Biología Celular y Molecular, Área Virosis de Insectos, Instituto de Microbiología Básica y Aplicada, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Buenos Aires, Argentina
| | - Gregorio Juan Mc Callum
- Cátedra de Biotecnología, Departamento de Microbiología, Inmunología, Biotecnología y Genética, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 956, Buenos Aires, 1113, Argentina
- Instituto de Nanobiotecnología (NANOBIOTEC), Facultad de Farmacia y Bioquímica, CONICET -Universidad de Buenos Aires, Junín 956, Sexto Piso, C1113AAD, 1113, Buenos Aires, Argentina
| | - Ignacio Smith
- Cátedra de Biotecnología, Departamento de Microbiología, Inmunología, Biotecnología y Genética, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 956, Buenos Aires, 1113, Argentina
- Instituto de Nanobiotecnología (NANOBIOTEC), Facultad de Farmacia y Bioquímica, CONICET -Universidad de Buenos Aires, Junín 956, Sexto Piso, C1113AAD, 1113, Buenos Aires, Argentina
| | - Franco Uriel Cuccovia Warlet
- Laboratorio de Ingeniería Genética y Biología Celular y Molecular, Área Virosis de Insectos, Instituto de Microbiología Básica y Aplicada, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Buenos Aires, Argentina
| | - María Victoria Nugnes
- Laboratorio de Ingeniería Genética y Biología Celular y Molecular, Área Virosis de Insectos, Instituto de Microbiología Básica y Aplicada, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Buenos Aires, Argentina
| | - María Victoria Miranda
- Cátedra de Biotecnología, Departamento de Microbiología, Inmunología, Biotecnología y Genética, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 956, Buenos Aires, 1113, Argentina
- Instituto de Nanobiotecnología (NANOBIOTEC), Facultad de Farmacia y Bioquímica, CONICET -Universidad de Buenos Aires, Junín 956, Sexto Piso, C1113AAD, 1113, Buenos Aires, Argentina
| | - Mariano Nicolás Belaich
- Laboratorio de Ingeniería Genética y Biología Celular y Molecular, Área Virosis de Insectos, Instituto de Microbiología Básica y Aplicada, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Buenos Aires, Argentina
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Monobac System-A Single Baculovirus for the Production of rAAV. Microorganisms 2021; 9:microorganisms9091799. [PMID: 34576695 PMCID: PMC8465638 DOI: 10.3390/microorganisms9091799] [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: 07/07/2021] [Revised: 08/09/2021] [Accepted: 08/13/2021] [Indexed: 11/28/2022] Open
Abstract
Large-scale manufacturing of rAAV is a bottleneck for the development of genetic disease treatments. The baculovirus/Sf9 cell system underpins the first rAAV treatment approved by EMA and remains one of the most advanced platforms for rAAV manufacturing. Despite early successes, rAAV is still a complex biomaterial to produce. Efficient production of the recombinant viral vector requires that AAV replicase and capsid genes be co-located with the recombinant AAV genome. Here, we present the Monobac system, a singular, modified baculovirus genome that contains all of these functions. To assess the relative yields between the dual baculovirus and Monobac systems, we prepared each system with a transgene encoding γSGC and evaluated vectors’ potency in vivo. Our results show that rAAV production using the Monobac system not only yields higher titers of rAAV vector but also a lower amount of DNA contamination from baculovirus.
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Tustian AD, Bak H. Assessment of quality attributes for adeno-associated viral vectors. Biotechnol Bioeng 2021; 118:4186-4203. [PMID: 34309017 DOI: 10.1002/bit.27905] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 07/21/2021] [Accepted: 07/22/2021] [Indexed: 12/24/2022]
Abstract
There is a strong and growing interest in the development and production of gene therapy products, including those utilizing adeno-associated virus (AAV) particles. This is evident with the increase in the number of clinical trials and agency approvals for AAV therapeutics. As bioproduction of AAV viral vectors matures, a quality by design (QbD) approach to process development can aid in process robustness and product quality. Furthermore, it may become a regulatory expectation. The first step in any QbD approach is to determine what physical, chemical, biological, or microbiological property or characteristic product attributes should be controlled within an appropriate limit, range, or distribution to ensure the desired product quality. Then predefined goals are set to allow proactive process development to design in quality. This review lists typical quality attributes used for release testing of AAV viral vectors and discusses these and selected attributes important to extended characterization studies in terms of safety, efficacy, and impact upon the patient immune response.
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Affiliation(s)
| | - Hanne Bak
- Regeneron Pharmaceuticals Inc., Tarrytown, NY, USA
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17
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Large EE, Silveria MA, Zane GM, Weerakoon O, Chapman MS. Adeno-Associated Virus (AAV) Gene Delivery: Dissecting Molecular Interactions upon Cell Entry. Viruses 2021; 13:1336. [PMID: 34372542 PMCID: PMC8310307 DOI: 10.3390/v13071336] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 07/08/2021] [Accepted: 07/08/2021] [Indexed: 12/13/2022] Open
Abstract
Human gene therapy has advanced from twentieth-century conception to twenty-first-century reality. The recombinant Adeno-Associated Virus (rAAV) is a major gene therapy vector. Research continues to improve rAAV safety and efficacy using a variety of AAV capsid modification strategies. Significant factors influencing rAAV transduction efficiency include neutralizing antibodies, attachment factor interactions and receptor binding. Advances in understanding the molecular interactions during rAAV cell entry combined with improved capsid modulation strategies will help guide the design and engineering of safer and more efficient rAAV gene therapy vectors.
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Affiliation(s)
| | | | | | | | - Michael S. Chapman
- Department of Biochemistry, University of Missouri, Columbia, MO 65201, USA; (E.E.L.); (M.A.S.); (G.M.Z.); (O.W.)
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18
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Wu Y, Han Z, Duan M, Jiang L, Tian T, Jin D, Wang Q, Xu F. Popularizing Recombinant Baculovirus-derived OneBac System for Laboratory Production of all Recombinant Adeno-associated Virus Vector Serotypes. Curr Gene Ther 2021; 21:167-176. [PMID: 33461466 DOI: 10.2174/1566523221666210118111657] [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: 11/06/2020] [Revised: 12/14/2020] [Accepted: 12/21/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND Recombinant adeno-associated virus (rAAV) has been widely used as an efficient transgenic vector in biomedical research, as well as gene therapy. Serotype-associated transduction efficiency, tissue- or cell-type tropism and immunological profile are major considerations in the various applications of rAAVs. There are increasing needs for different serotypes of rAAV, either naturally isolated or artificially engineered. However, affordable and scalable production of a desired serotype of rAAV remains very difficult, especially for researchers lacking relevant experience. OBJECTIVE On the basis of our previously established single recombinant baculovirus expression vector (BEV)-derived OneBac system, we have optimized the process and expanded the rAAV production range to the full range of serotypes rAAV1-13. METHODS Firstly, the AAV Cap gene was optimized to translate by ribosome leaky scanning and the gene of interest (GOI) was cloned into the pFD/Cap-(ITR-GOI)-Rep2 shuttle plasmid. Following the classical Bac-to-Bac method, sufficient BEV stock containing all rAAV packaging elements can be quickly obtained. Finally, we can repeatedly scale up the production of rAAVs in one week by using a single BEV to infect suspension-cultured Sf9 cells. The rAAV1-13 shows relatively high yields ranging from 5×104 to 4×105 VG/cell. More than 1×1015 VG purified rAAVs can be easily obtained from 5 L suspension-cultured Sf9 cells. RESULTS As expected, rAAV serotypes 1-13 show different potencies for in vitro transduction and cell-type tropisms. CONCLUSION In summary, the single BEV-derived OneBac system should prove popular for laboratory scaling-up production of any serotype of rAAV.
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Affiliation(s)
- Yang Wu
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Center for Magnetic Resonance, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Zengpeng Han
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Center for Magnetic Resonance, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Mingzhu Duan
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Center for Magnetic Resonance, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Liangyu Jiang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Center for Magnetic Resonance, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Tiantian Tian
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Center for Magnetic Resonance, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Dingyu Jin
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Center for Magnetic Resonance, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Qitian Wang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Center for Magnetic Resonance, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Fuqiang Xu
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Center for Magnetic Resonance, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan, 430071, China
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19
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Wörner TP, Bennett A, Habka S, Snijder J, Friese O, Powers T, Agbandje-McKenna M, Heck AJR. Adeno-associated virus capsid assembly is divergent and stochastic. Nat Commun 2021; 12:1642. [PMID: 33712599 PMCID: PMC7955066 DOI: 10.1038/s41467-021-21935-5] [Citation(s) in RCA: 79] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 02/04/2021] [Indexed: 12/26/2022] Open
Abstract
Adeno-associated viruses (AAVs) are increasingly used as gene therapy vectors. AAVs package their genome in a non-enveloped T = 1 icosahedral capsid of ~3.8 megaDalton, consisting of 60 subunits of 3 distinct viral proteins (VPs), which vary only in their N-terminus. While all three VPs play a role in cell-entry and transduction, their precise stoichiometry and structural organization in the capsid has remained elusive. Here we investigate the composition of several AAV serotypes by high-resolution native mass spectrometry. Our data reveal that the capsids assemble stochastically, leading to a highly heterogeneous population of capsids of variable composition, whereby even the single-most abundant VP stoichiometry represents only a small percentage of the total AAV population. We estimate that virtually every AAV capsid in a particular preparation has a unique composition. The systematic scoring of the simulations against experimental native MS data offers a sensitive new method to characterize these therapeutically important heterogeneous capsids.
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Affiliation(s)
- Tobias P Wörner
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Padualaan 8, Utrecht, The Netherlands
- Netherlands Proteomics Center, Padualaan 8, Utrecht, The Netherlands
| | - Antonette Bennett
- Department of Biochemistry and Molecular Biology, Center for Structural Biology, the McKnight Brain Institute, 1200 Newell Drive, Gainesville, FL, USA
| | - Sana Habka
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Padualaan 8, Utrecht, The Netherlands
- Netherlands Proteomics Center, Padualaan 8, Utrecht, The Netherlands
| | - Joost Snijder
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Padualaan 8, Utrecht, The Netherlands
- Netherlands Proteomics Center, Padualaan 8, Utrecht, The Netherlands
| | - Olga Friese
- Biotherapeutics Pharmaceutical Sciences, Pfizer WRDM, 700 Chesterfield Parkway W, Gainesville, MO, USA
| | - Thomas Powers
- Biotherapeutics Pharmaceutical Sciences, Pfizer WRDM, 700 Chesterfield Parkway W, Gainesville, MO, USA
| | - Mavis Agbandje-McKenna
- Department of Biochemistry and Molecular Biology, Center for Structural Biology, the McKnight Brain Institute, 1200 Newell Drive, Gainesville, FL, USA
| | - Albert J R Heck
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Padualaan 8, Utrecht, The Netherlands.
- Netherlands Proteomics Center, Padualaan 8, Utrecht, The Netherlands.
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20
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Joshi PRH, Venereo-Sanchez A, Chahal PS, Kamen AA. Advancements in molecular design and bioprocessing of recombinant adeno-associated virus gene delivery vectors using the insect-cell baculovirus expression platform. Biotechnol J 2021; 16:e2000021. [PMID: 33277815 DOI: 10.1002/biot.202000021] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Revised: 11/27/2020] [Indexed: 01/23/2023]
Abstract
Despite rapid progress in the field, scalable high-yield production of adeno-associated virus (AAV) is still one of the critical bottlenecks the manufacturing sector is facing. The insect cell-baculovirus expression vector system (IC-BEVS) has emerged as a mainstream platform for the scalable production of recombinant proteins with clinically approved products for human use. In this review, we provide a detailed overview of the advancements in IC-BEVS for rAAV production. Since the first report of baculovirus-induced production of rAAV vector in insect cells in 2002, this platform has undergone significant improvements, including enhanced stability of Bac-vector expression and a reduced number of baculovirus-coinfections. The latter streamlining strategy led to the eventual development of the Two-Bac, One-Bac, and Mono-Bac systems. The one baculovirus system consisting of an inducible packaging insect cell line was further improved to enhance the AAV vector quality and potency. In parallel, the implementation of advanced manufacturing approaches and control of critical processing parameters have demonstrated promising results with process validation in large-scale bioreactor runs. Moreover, optimization of the molecular design of vectors to enable higher cell-specific yields of functional AAV particles combined with bioprocess intensification strategies may also contribute to addressing current and future manufacturing challenges.
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Affiliation(s)
- Pranav R H Joshi
- Department of Bioengineering, McGill University, Montréal, Quebec, Canada
| | | | - Parminder S Chahal
- Human Health Therapeutics Portfolio, National Research Council of Canada, Montréal, Quebec, Canada
| | - Amine A Kamen
- Department of Bioengineering, McGill University, Montréal, Quebec, Canada
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21
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Mietzsch M, Smith JK, Yu JC, Banala V, Emmanuel SN, Jose A, Chipman P, Bhattacharya N, McKenna R, Agbandje-McKenna M. Characterization of AAV-Specific Affinity Ligands: Consequences for Vector Purification and Development Strategies. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2020; 19:362-373. [PMID: 33145372 PMCID: PMC7591348 DOI: 10.1016/j.omtm.2020.10.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 10/01/2020] [Indexed: 02/06/2023]
Abstract
Affinity-based purification of adeno-associated virus (AAV) vectors has replaced density-based methods for vectors used in clinical settings. This method utilizes camelid single-domain antibodies recognizing AAV capsids. These include AVB Sepharose (AVB) and POROS CaptureSelect affinity ligand for AAV8 (CSAL8) and AAV9 (CSAL9). In this study, we utilized cryo-electron microscopy and 3D image reconstruction to map the binding sites of these affinity ligands on the capsids of several AAV serotypes, including AAV1, AAV2, AAV5, AAV8, and AAV9, representing the range of sequence and structure diversity among AAVs. The AAV-ligand complex structures showed that AVB and CSAL9 bound to the 5-fold capsid region, although in different orientations, and CSAL8 bound to the side of the 3-fold protrusion. The AAV contact residues required for ligand binding, and thus AAV purification, and the ability of the ligands to neutralize infection were analyzed. The data show that only a few residues within the epitopes served to block affinity ligand binding. Neutralization was observed for AAV1 and AAV5 with AVB, for AAV1 with CSAL8, and for AAV9 with CSAL9, associated with regions that overlap with epitopes for neutralizing monoclonal antibodies against these capsids. This information is critical and could be generally applicable in the development of novel AAV vectors amenable to affinity column purification.
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Affiliation(s)
- Mario Mietzsch
- Department of Biochemistry and Molecular Biology, Center for Structural Biology, McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, FL, USA
| | - J Kennon Smith
- Department of Biochemistry and Molecular Biology, Center for Structural Biology, McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Jennifer C Yu
- Department of Biochemistry and Molecular Biology, Center for Structural Biology, McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Vibhu Banala
- Department of Biochemistry and Molecular Biology, Center for Structural Biology, McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Shanan N Emmanuel
- Department of Biochemistry and Molecular Biology, Center for Structural Biology, McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Ariana Jose
- Department of Biochemistry and Molecular Biology, Center for Structural Biology, McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Paul Chipman
- Department of Biochemistry and Molecular Biology, Center for Structural Biology, McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Nilakshee Bhattacharya
- Biological Science Imaging Resource, Department of Biological Sciences, Florida State University, Tallahassee, FL, USA
| | - Robert McKenna
- Department of Biochemistry and Molecular Biology, Center for Structural Biology, McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Mavis Agbandje-McKenna
- Department of Biochemistry and Molecular Biology, Center for Structural Biology, McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, FL, USA
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22
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Wu Y, Mei T, Jiang L, Han Z, Dong R, Yang T, Xu F. Development of Versatile and Flexible Sf9 Packaging Cell Line-Dependent OneBac System for Large-Scale Recombinant Adeno-Associated Virus Production. Hum Gene Ther Methods 2020; 30:172-183. [PMID: 31566024 PMCID: PMC6834060 DOI: 10.1089/hgtb.2019.123] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Recombinant adeno-associated viruses (rAAVs) are excellent vectors for gene delivery. However, current Sf9/Cap-Rep packaging cell line-dependent OneBac systems still lack versatility and flexibility for large-scale production of rAAVs. In this study, we developed an improved OneBac system that includes a novel dual-function baculovirus expression vector (BEV) termed BEV/Cap-(ITR-GOI) that carries both the AAV Cap gene and rAAV genome inverted terminal repeat (ITR) sequences flanking the gene of interest (GOI), a versatile Sf9-GFP/Rep packaging cell line that harbors silent copies of the AAV2 Rep gene that can be expressed after BEV infection, and constitutively expressed green fluorescent protein (GFP) reporter genes to facilitate cell line screening. The BEV/Cap-(ITR-GOI) construct allows flexibility to switch among different Cap gene serotypes using simple BEV reconstruction, and is stable for at least five serial passages. Furthermore, the Sf9-GFP/Rep stable cell line is versatile for production of different rAAV serotypes. The yield levels for rAAV2, rAAV8, and rAAV9 exceeded 105 vector genomes (VG) per cell, which is similar to other currently available large-scale rAAV production systems. The new Bac system-derived rAAVs have biophysical properties similar to HEK293 cell-derived rAAVs, as well as high quality and activity. In summary, the novel Sf9-GFP/Rep packaging cell line-dependent OneBac system can facilitate large-scale rAAV production and rAAV-based gene therapy.
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Affiliation(s)
- Yang Wu
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Center for Magnetic Resonance, Brain Research Center, Wuhan Institute of Physics and Mathematics, Center for Excellence in Brain Science and Intelligent Technology, Chinese Academy of Sciences, Wuhan, P.R. China
| | - Ting Mei
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Center for Magnetic Resonance, Brain Research Center, Wuhan Institute of Physics and Mathematics, Center for Excellence in Brain Science and Intelligent Technology, Chinese Academy of Sciences, Wuhan, P.R. China
| | - Liangyu Jiang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Center for Magnetic Resonance, Brain Research Center, Wuhan Institute of Physics and Mathematics, Center for Excellence in Brain Science and Intelligent Technology, Chinese Academy of Sciences, Wuhan, P.R. China
| | - Zengpeng Han
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Center for Magnetic Resonance, Brain Research Center, Wuhan Institute of Physics and Mathematics, Center for Excellence in Brain Science and Intelligent Technology, Chinese Academy of Sciences, Wuhan, P.R. China
| | - Ruping Dong
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Center for Magnetic Resonance, Brain Research Center, Wuhan Institute of Physics and Mathematics, Center for Excellence in Brain Science and Intelligent Technology, Chinese Academy of Sciences, Wuhan, P.R. China
| | - Tian Yang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Center for Magnetic Resonance, Brain Research Center, Wuhan Institute of Physics and Mathematics, Center for Excellence in Brain Science and Intelligent Technology, Chinese Academy of Sciences, Wuhan, P.R. China
| | - Fuqiang Xu
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Center for Magnetic Resonance, Brain Research Center, Wuhan Institute of Physics and Mathematics, Center for Excellence in Brain Science and Intelligent Technology, Chinese Academy of Sciences, Wuhan, P.R. China
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23
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Thorne B, Takeya R, Vitelli F, Swanson X. Gene Therapy. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2019; 165:351-399. [PMID: 28289769 DOI: 10.1007/10_2016_53] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Gene therapy refers to a rapidly growing field of medicine in which genes are introduced into the body to treat or prevent diseases. Although a variety of methods can be used to deliver the genetic materials into the target cells and tissues, modified viral vectors represent one of the more common delivery routes because of its transduction efficiency for therapeutic genes. Since the introduction of gene therapy concept in the 1970s, the field has advanced considerably with notable clinical successes being demonstrated in many clinical indications in which no standard treatment options are currently available. It is anticipated that the clinical success the field observed in recent years can drive requirements for more scalable, robust, cost effective, and regulatory-compliant manufacturing processes. This review provides a brief overview of the current manufacturing technologies for viral vectors production, drawing attention to the common upstream and downstream production process platform that is applicable across various classes of viral vectors and their unique manufacturing challenges as compared to other biologics. In addition, a case study of an industry-scale cGMP production of an AAV-based gene therapy product performed at 2,000 L-scale is presented. The experience and lessons learned from this largest viral gene therapy vector production run conducted to date as discussed and highlighted in this review should contribute to future development of commercial viable scalable processes for vial gene therapies.
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Affiliation(s)
- Barb Thorne
- Thorne Bio-Consulting LLC, Sammamish, WA, USA
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24
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Joshi PR, Cervera L, Ahmed I, Kondratov O, Zolotukhin S, Schrag J, Chahal PS, Kamen AA. Achieving High-Yield Production of Functional AAV5 Gene Delivery Vectors via Fedbatch in an Insect Cell-One Baculovirus System. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2019; 13:279-289. [PMID: 30886878 PMCID: PMC6404649 DOI: 10.1016/j.omtm.2019.02.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 02/07/2019] [Indexed: 11/19/2022]
Abstract
Despite numerous advancements in production protocols, manufacturing AAV to meet exceptionally high demand (1016–1017 viral genomes [VGs]) in late clinical stages and for eventual systemic delivery poses significant challenges. Here, we report an efficient, simple, scalable, robust AAV5 production process utilizing the most recent modification of the OneBac platform. An increase in volumetric yield of genomic particles by ∼6-fold and functional particles by ∼20-fold was achieved by operating a high-cell-density process in shake flasks and bioreactors that involves an Sf9-based rep/cap stable cell line grown at a density of about 10 million cells/mL infected with a single baculovirus. The overall volumetric yields of genomic (VG) and bioactive particles (enhanced transducing units [ETUs]) in representative fedbatch bioreactor runs ranged from 2.5 to 3.5 × 1014 VG/L and from 1 to 2 × 1011 ETU/L. Analytical ultracentrifugation analyses of affinity-purified AAV vector samples from side-by-side batch and fedbatch production runs showed vector preparations with a full and empty particle distribution of 20%–30% genomic and 70%–80% empty particles. Moreover, the stoichiometric analysis of capsid proteins from fedbatch production in shake flask and bioreactor run samples demonstrated the incorporation of higher VP1 subunits, resulting in better functionality.
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Affiliation(s)
- Pranav R.H. Joshi
- Viral Vectors and Vaccine Bioprocessing Group, Department of Bioengineering, McGill University, Montreal, QC H3A 0E9, Canada
| | - Laura Cervera
- Viral Vectors and Vaccine Bioprocessing Group, Department of Bioengineering, McGill University, Montreal, QC H3A 0E9, Canada
| | - Ibrahim Ahmed
- Viral Vectors and Vaccine Bioprocessing Group, Department of Bioengineering, McGill University, Montreal, QC H3A 0E9, Canada
| | - Oleksandr Kondratov
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Sergei Zolotukhin
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Joseph Schrag
- Human Health Therapeutics Portfolio, National Research Council of Canada, Montreal, QC H4P 2R2, Canada
| | - Parminder S. Chahal
- Human Health Therapeutics Portfolio, National Research Council of Canada, Montreal, QC H4P 2R2, Canada
| | - Amine A. Kamen
- Viral Vectors and Vaccine Bioprocessing Group, Department of Bioengineering, McGill University, Montreal, QC H3A 0E9, Canada
- Corresponding author: Amine Kamen, Viral Vectors and Vaccine Bioprocessing Group, Department of Bioengineering, McGill University, Montreal, QC H3A 0E9, Canada.
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25
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Optimization of viral protein ratios for production of rAAV serotype 5 in the baculovirus system. Gene Ther 2018; 25:415-424. [PMID: 30069004 DOI: 10.1038/s41434-018-0034-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2018] [Revised: 05/21/2018] [Accepted: 06/14/2018] [Indexed: 01/09/2023]
Abstract
Recombinant adeno-associated virus (rAAV) has become the vector of choice for the development of novel human gene therapies. High-yield manufacturing of high-quality vectors can be achieved using the baculovirus expression vector system. However, efficient production of rAAV in this insect cell-based system requires a genetic redesign of the viral protein 1 (VP1) operon. In this study, we generated a library of rationally designed rAAV serotype 5 variants with modulations in the translation-initiation region of VP1 and investigated the potency of the resulting vectors. We found that the initiation strength at the VP1 translational start had downstream effects on the VP2/VP3 ratio. Excessive incorporation of VP3 into a vector type decreased potency, even when the VP1/VP2 ratio was in balance. Finally, we successfully generated a potent rAAV vector based on serotype 5 with a balanced VP1/VP2/VP3 stoichiometry.
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26
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François A, Bouzelha M, Lecomte E, Broucque F, Penaud-Budloo M, Adjali O, Moullier P, Blouin V, Ayuso E. Accurate Titration of Infectious AAV Particles Requires Measurement of Biologically Active Vector Genomes and Suitable Controls. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2018; 10:223-236. [PMID: 30112419 PMCID: PMC6090651 DOI: 10.1016/j.omtm.2018.07.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 07/10/2018] [Indexed: 12/12/2022]
Abstract
Although the clinical use of recombinant adeno-associated virus (rAAV) vectors is constantly increasing, the development of suitable quality control methods is still needed for accurate vector characterization. Among the quality criteria, the titration of infectious particles is critical to determine vector efficacy. Different methods have been developed for the measurement of rAAV infectivity in vitro, based on detection of vector genome replication in trans-complementing cells infected with adenovirus, detection of transgene expression in permissive cells, or simply detection of intracellular vector genomes following the infection of indicator cells. In the present study, we have compared these methods for the titration of infectious rAAV8 vector particles, and, to assess their ability to discriminate infectious and non-infectious rAAV serotype 8 particles, we have generated a VP1-defective AAV8-GFP vector. Since VP1 is required to enter the cell nucleus, the lack of VP1 should drastically reduce the infectivity of rAAV particles. The AAV8 reference standard material was used as a positive control. Our results demonstrated that methods based on measurement of rAAV biological activity (i.e., vector genome replication or transgene expression) were able to accurately discriminate infectious versus non-infectious particles, whereas methods simply measuring intracellular vector genomes were not. Several cell fractionation protocols were tested in an attempt to specifically measure vector genomes that had reached the nucleus, but genomes from wild-type and VP1-defective AAV8 particles were equally detected in the nuclear fraction by qPCR. These data highlight the importance of using suitable controls, including a negative control, for the development of biological assays such as infectious unit titration.
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Affiliation(s)
- Achille François
- INSERM UMR1089, University of Nantes, Centre Hospitalier Universitaire, Nantes, France
| | - Mohammed Bouzelha
- INSERM UMR1089, University of Nantes, Centre Hospitalier Universitaire, Nantes, France
| | - Emilie Lecomte
- INSERM UMR1089, University of Nantes, Centre Hospitalier Universitaire, Nantes, France
| | - Frédéric Broucque
- INSERM UMR1089, University of Nantes, Centre Hospitalier Universitaire, Nantes, France
| | - Magalie Penaud-Budloo
- INSERM UMR1089, University of Nantes, Centre Hospitalier Universitaire, Nantes, France
| | - Oumeya Adjali
- INSERM UMR1089, University of Nantes, Centre Hospitalier Universitaire, Nantes, France
| | - Philippe Moullier
- INSERM UMR1089, University of Nantes, Centre Hospitalier Universitaire, Nantes, France
| | - Véronique Blouin
- INSERM UMR1089, University of Nantes, Centre Hospitalier Universitaire, Nantes, France
| | - Eduard Ayuso
- INSERM UMR1089, University of Nantes, Centre Hospitalier Universitaire, Nantes, France
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27
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Genetics instability of wtAAV2 genome and AAV promoter activities in the Baculovirus/Sf9 cells system. PLoS One 2018; 13:e0199866. [PMID: 29975713 PMCID: PMC6033426 DOI: 10.1371/journal.pone.0199866] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 06/14/2018] [Indexed: 12/24/2022] Open
Abstract
The human Adeno-Associated Virus serotype 2 (wtAAV2) is a common non-pathological virus and its recombinant form (rAAV) is widely used as gene therapy vector. Although rAAVs are routinely produced in the Baculovirus/Sf9 cell system, wtAAV2 has never been studied in this context. We tried to produce wtAAV2 in the baculovirus/Sf9 cell system hypothesizing that the wtAAV2 may be considered as a normal recombinant AAV transgene. Through our attempts to produce wtAAV2 in Baculovirus/Sf9, we found that wtAAV2 p5 promoter, which controls the expression of large Rep proteins in mammalian cells, was active in this system. p5 promoter activity in the baculovirus/Sf9 cell system leads to the expression of Rep78 that finally excises wtAAV2 genome from the baculovirus genome during the earliest phases of baculovirus stock production. Via p5 promoter expression kinetics and strand specific RNA-Seq analysis of wtAAV2, rAAV and Rep2/Cap2 cassettes in the baculovirus context we could demonstrate that wtAAV2 native promoters, p5, p19 and p40 are all active in the context of the baculovirus system and lead to the expression of different proteins and peptides. In addition, this study has proven that the baculovirus brings at least some of the helper functions needed in the AAV replication/life cycle.
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28
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Wu Y, Jiang L, Geng H, Yang T, Han Z, He X, Lin K, Xu F. A Recombinant Baculovirus Efficiently Generates Recombinant Adeno-Associated Virus Vectors in Cultured Insect Cells and Larvae. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2018; 10:38-47. [PMID: 29988889 PMCID: PMC6034586 DOI: 10.1016/j.omtm.2018.05.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2017] [Accepted: 05/21/2018] [Indexed: 12/12/2022]
Abstract
Current large-scale recombinant adeno-associated virus (rAAV) production systems based on the baculovirus expression vector (BEV) remain complicated and cost-intensive, and they lack versatility and flexibility. Here we present a novel recombinant baculovirus integrated with all packaging elements for the production of rAAV. To optimize BEV construction, ribosome leaky-scanning mechanism was used to express AAV Rep and Cap proteins downstream of the PH and P10 promoters in the pFast.Bac.Dual vector, respectively, and the rAAV genome was inserted between the two promoters. The yields of rAAV2, rAAV8, and rAAV9 derived from the BEV-infected Sf9 cells exceeded 105 vector genomes (VG) per cell. The BEV was shown to be stable and showed no apparent decrease of rAAV yield after at least four serial passages. The rAAVs derived from the new Bac system displayed high-quality and high-transduction activity. Additionally, rAAV2 could be efficiently generated from BEV-infected beet armyworm larvae at a per-larvae yield of 2.75 ± 1.66 × 1010 VG. The rAAV2 derived from larvae showed a structure similar to the rAAV2 derived from HEK293 cells, and it also displayed high-transduction activity. In summary, the novel BEV is ideally suitable for large-scale rAAV production. Further, this study exploits a potential cost-efficient platform for rAAV production in insect larvae.
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Affiliation(s)
- Yang Wu
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China.,Brain Research Center, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
| | - Liangyu Jiang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China.,Brain Research Center, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
| | - Hao Geng
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China.,Brain Research Center, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
| | - Tian Yang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China.,Brain Research Center, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
| | - Zengpeng Han
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China.,Brain Research Center, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
| | - Xiaobing He
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China.,Brain Research Center, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
| | - Kunzhang Lin
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China.,Brain Research Center, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
| | - Fuqiang Xu
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China.,Brain Research Center, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China.,Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China
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29
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Arruda VR, Doshi BS, Samelson-Jones BJ. Emerging therapies for hemophilia: controversies and unanswered questions. F1000Res 2018; 7. [PMID: 29770199 PMCID: PMC5931262 DOI: 10.12688/f1000research.12491.1] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/13/2018] [Indexed: 12/21/2022] Open
Abstract
Several new therapies for hemophilia have emerged in recent years. These strategies range from extended half-life factor replacement products and non-factor options with improved pharmacokinetic profiles to gene therapy aiming for phenotypic cure. While these products have the potential to change hemophilia care dramatically, several challenges and questions remain regarding broader applicability, long-term safety, and which option to pursue for each patient. Here, we review these emerging therapies with a focus on controversies and unanswered questions in each category.
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Affiliation(s)
- Valder R Arruda
- The Children's Hospital of Philadelphia, Philadelphia, PA, USA.,Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.,Raymond G. Perelman Center for Cellular and Molecular Therapeutics, Philadelphia, PA, USA
| | - Bhavya S Doshi
- The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Benjamin J Samelson-Jones
- The Children's Hospital of Philadelphia, Philadelphia, PA, USA.,Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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30
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Reid CA, Lipinski DM. Small and Micro-Scale Recombinant Adeno-Associated Virus Production and Purification for Ocular Gene Therapy Applications. Methods Mol Biol 2018; 1715:19-31. [PMID: 29188503 DOI: 10.1007/978-1-4939-7522-8_2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Over the past two decades recombinant adeno-associated virus (rAAV) vectors have emerged as the gold standard for transferring genetic material to cells of the retina. The ability to effectively produce small batches of rAAV vector at high enough purity for in vitro and in vivo applications in a cost-effective manner is paramount. This is particularly the case when conducting preclinical experiments to screen novel serotypes, promoters or transgenes, where production of numerous vector batches is required. Current vector production methods often produce large quantities of vector, limiting the cost-effectiveness and practicality of such screening experiments, which often require only small volumes of vector to carry out. Herein, we describe a method to produce high titer (1012-1013 vector genomes (vg)/mL) rAAV vector on small (~100 μL) or micro (~15 μL) scale for in vitro and in vivo applications.
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Affiliation(s)
- Christopher A Reid
- Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Daniel M Lipinski
- Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, WI, USA.
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neuroscience, University of Oxford, Oxford, UK.
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31
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Aponte-Ubillus JJ, Barajas D, Peltier J, Bardliving C, Shamlou P, Gold D. Molecular design for recombinant adeno-associated virus (rAAV) vector production. Appl Microbiol Biotechnol 2017; 102:1045-1054. [PMID: 29204900 PMCID: PMC5778157 DOI: 10.1007/s00253-017-8670-1] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 11/17/2017] [Accepted: 11/20/2017] [Indexed: 12/14/2022]
Abstract
Recombinant adeno-associated virus (rAAV) vectors are increasingly popular tools for gene therapy applications. Their non-pathogenic status, low inflammatory potential, availability of viral serotypes with different tissue tropisms, and prospective long-lasting gene expression are important attributes that make rAAVs safe and efficient therapeutic options. Over the last three decades, several groups have engineered recombinant AAV-producing platforms, yielding high titers of transducing vector particles. Current specific productivity yields from different platforms range from 103 to 105 vector genomes (vg) per cell, and there is an ongoing effort to improve vector yields in order to satisfy high product demands required for clinical trials and future commercialization. Crucial aspects of vector production include the molecular design of the rAAV-producing host cell line along with the design of AAV genes, promoters, and regulatory elements. Appropriately, configuring and balancing the expression of these elements not only contributes toward high productivity, it also improves process robustness and product quality. In this mini-review, the rational design of rAAV-producing expression systems is discussed, with special attention to molecular strategies that contribute to high-yielding, biomanufacturing-amenable rAAV production processes. Details on molecular optimization from four rAAV expression systems are covered: adenovirus, herpesvirus, and baculovirus complementation systems, as well as a recently explored yeast expression system.
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Affiliation(s)
- Juan Jose Aponte-Ubillus
- Biomarin Pharmaceutical Inc., 105 Digital drive, Novato, CA, 94949, USA.
- Keck Graduate Institute of Applied Life Sciences, 535 Watson drive, Claremont, CA, 91711, USA.
| | - Daniel Barajas
- Biomarin Pharmaceutical Inc., 105 Digital drive, Novato, CA, 94949, USA
| | - Joseph Peltier
- Biomarin Pharmaceutical Inc., 105 Digital drive, Novato, CA, 94949, USA
| | - Cameron Bardliving
- Keck Graduate Institute of Applied Life Sciences, 535 Watson drive, Claremont, CA, 91711, USA
| | - Parviz Shamlou
- Keck Graduate Institute of Applied Life Sciences, 535 Watson drive, Claremont, CA, 91711, USA
| | - Daniel Gold
- Biomarin Pharmaceutical Inc., 105 Digital drive, Novato, CA, 94949, USA
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32
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Wang Q, Wu Z, Zhang J, Firrman J, Wei H, Zhuang Z, Liu L, Miao L, Hu Y, Li D, Diao Y, Xiao W. A Robust System for Production of Superabundant VP1 Recombinant AAV Vectors. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2017; 7:146-156. [PMID: 29255740 PMCID: PMC5721209 DOI: 10.1016/j.omtm.2017.11.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 11/01/2017] [Indexed: 01/31/2023]
Abstract
Recombinant adeno-associated viral (rAAV) vectors have been widely used in human gene therapy. One major impediment to its broad application is the inability to produce high-quality vectors in mass quantity. Here, an efficient and scalable suspension cell culture system for the production of rAAV vectors is described. In this system, the AAV trans factors, Rep78, Rep52, VP1, VP2, and VP3, were stably integrated into a single vaccinia virus carrier by maximizing the use of alternative codons between genes with identical amino acids, and the cis rAAV genome was carried by an E1/E3 gene-deleted adenovirus. Infection of improved, E1 integrated, suspension-cultured cells with these two viral vectors resulted in the robust production of rAAV vectors. The newly enhanced system can consistently produce ∼1 × 1015 genome containing rAAV vectors per liter of suspension cells. Moreover, the capsid composition of rAAV vectors produced by this system is markedly different from those produced using the traditional system in that the VP1 protein is more abundant than the VP2 protein (19:1 versus 1:1). The unique VP1 superabundant rAAV vectors produced in this new system exhibited improved transduction in vivo after intravitreal injection.
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Affiliation(s)
- Qizhao Wang
- School of Biomedical Sciences, Huaqiao University, Quanzhou, Fujian, China.,Sol Sherry Thrombosis Research Center, Temple University, Philadelphia, PA, USA.,Byers Eye Institute, Stanford University School of Medicine, Stanford, CA, USA
| | - Zhongren Wu
- Sol Sherry Thrombosis Research Center, Temple University, Philadelphia, PA, USA
| | - Junping Zhang
- Sol Sherry Thrombosis Research Center, Temple University, Philadelphia, PA, USA
| | - Jenni Firrman
- Department of Microbiology and Immunology, Temple University, Philadelphia, PA, USA.,United States Department of Agriculture, ARS, ERRC, Wyndmoor, PA, USA
| | - Hongying Wei
- Sol Sherry Thrombosis Research Center, Temple University, Philadelphia, PA, USA
| | - Zhengjing Zhuang
- School of Biomedical Sciences, Huaqiao University, Quanzhou, Fujian, China
| | - LinShu Liu
- United States Department of Agriculture, ARS, ERRC, Wyndmoor, PA, USA
| | - Linqing Miao
- Shriners Hospital Pediatric Research Center, Temple University, Philadelphia, PA, USA
| | - Yang Hu
- Byers Eye Institute, Stanford University School of Medicine, Stanford, CA, USA
| | - Dong Li
- Department of Clinical Laboratory, Tongji Hospital of Tongji University, Shanghai, China
| | - Yong Diao
- School of Biomedical Sciences, Huaqiao University, Quanzhou, Fujian, China
| | - Weidong Xiao
- School of Biomedical Sciences, Huaqiao University, Quanzhou, Fujian, China.,Sol Sherry Thrombosis Research Center, Temple University, Philadelphia, PA, USA.,Department of Microbiology and Immunology, Temple University, Philadelphia, PA, USA.,Cardiovascular Research Center, Temple University, Philadelphia, PA, USA.,Department of Clinical Laboratory, Tongji Hospital of Tongji University, Shanghai, China
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33
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Grosse S, Penaud-Budloo M, Herrmann AK, Börner K, Fakhiri J, Laketa V, Krämer C, Wiedtke E, Gunkel M, Ménard L, Ayuso E, Grimm D. Relevance of Assembly-Activating Protein for Adeno-associated Virus Vector Production and Capsid Protein Stability in Mammalian and Insect Cells. J Virol 2017; 91:e01198-17. [PMID: 28768875 PMCID: PMC5625497 DOI: 10.1128/jvi.01198-17] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 07/28/2017] [Indexed: 12/16/2022] Open
Abstract
The discovery that adeno-associated virus 2 (AAV2) encodes an eighth protein, called assembly-activating protein (AAP), transformed our understanding of wild-type AAV biology. Concurrently, it raised questions about the role of AAP during production of recombinant vectors based on natural or molecularly engineered AAV capsids. Here, we show that AAP is indeed essential for generation of functional recombinant AAV2 vectors in both mammalian and insect cell-based vector production systems. Surprisingly, we observed that AAV2 capsid proteins VP1 to -3 are unstable in the absence of AAP2, likely due to rapid proteasomal degradation. Inhibition of the proteasome led to an increase of intracellular VP1 to -3 but neither triggered assembly of functional capsids nor promoted nuclear localization of the capsid proteins. Together, this underscores the crucial and unique role of AAP in the AAV life cycle, where it rapidly chaperones capsid assembly, thus preventing degradation of free capsid proteins. An expanded analysis comprising nine alternative AAV serotypes (1, 3 to 9, and rh10) showed that vector production always depends on the presence of AAP, with the exceptions of AAV4 and AAV5, which exhibited AAP-independent, albeit low-level, particle assembly. Interestingly, AAPs from all 10 serotypes could cross-complement AAP-depleted helper plasmids during vector production, despite there being distinct intracellular AAP localization patterns. These were most pronounced for AAP4 and AAP5, congruent with their inability to rescue an AAV2/AAP2 knockout. We conclude that AAP is key for assembly of genuine capsids from at least 10 different AAV serotypes, which has implications for vectors derived from wild-type or synthetic AAV capsids.IMPORTANCE Assembly of adeno-associated virus 2 (AAV2) is regulated by the assembly-activating protein (AAP), whose open reading frame overlaps with that of the viral capsid proteins. As the majority of evidence was obtained using virus-like particles composed solely of the major capsid protein VP3, AAP's role in and relevance for assembly of genuine AAV capsids have remained largely unclear. Thus, we established a trans-complementation assay permitting assessment of AAP functionality during production of recombinant vectors based on complete AAV capsids and derived from any serotype. We find that AAP is indeed a critical factor not only for AAV2, but also for generation of vectors derived from nine other AAV serotypes. Moreover, we identify a new role of AAP in maintaining capsid protein stability in mammalian and insect cells. Thereby, our study expands our current understanding of AAV/AAP biology, and it concomitantly provides insights into the importance of AAP for AAV vector production.
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Affiliation(s)
- Stefanie Grosse
- Department of Infectious Diseases/Virology, Heidelberg University Hospital, Cluster of Excellence CellNetworks, Heidelberg, Germany
- BioQuant Center, University of Heidelberg, Heidelberg, Germany
| | - Magalie Penaud-Budloo
- INSERM UMR1089, University of Nantes, Centre Hospitalier Universitaire, Nantes, France
| | - Anne-Kathrin Herrmann
- Department of Infectious Diseases/Virology, Heidelberg University Hospital, Cluster of Excellence CellNetworks, Heidelberg, Germany
- BioQuant Center, University of Heidelberg, Heidelberg, Germany
| | - Kathleen Börner
- Department of Infectious Diseases/Virology, Heidelberg University Hospital, Cluster of Excellence CellNetworks, Heidelberg, Germany
- BioQuant Center, University of Heidelberg, Heidelberg, Germany
- German Center for Infection Research, Partner Site Heidelberg, Heidelberg, Germany
| | - Julia Fakhiri
- Department of Infectious Diseases/Virology, Heidelberg University Hospital, Cluster of Excellence CellNetworks, Heidelberg, Germany
- BioQuant Center, University of Heidelberg, Heidelberg, Germany
| | - Vibor Laketa
- Department of Infectious Diseases/Virology, Heidelberg University Hospital, Cluster of Excellence CellNetworks, Heidelberg, Germany
- German Center for Infection Research, Partner Site Heidelberg, Heidelberg, Germany
| | - Chiara Krämer
- Department of Infectious Diseases/Virology, Heidelberg University Hospital, Cluster of Excellence CellNetworks, Heidelberg, Germany
- BioQuant Center, University of Heidelberg, Heidelberg, Germany
| | - Ellen Wiedtke
- Department of Infectious Diseases/Virology, Heidelberg University Hospital, Cluster of Excellence CellNetworks, Heidelberg, Germany
- BioQuant Center, University of Heidelberg, Heidelberg, Germany
| | - Manuel Gunkel
- BioQuant Center, University of Heidelberg, Heidelberg, Germany
- CellNetworks Advanced Biological Screening Facility, University of Heidelberg, Heidelberg, Germany
| | - Lucie Ménard
- INSERM UMR1089, University of Nantes, Centre Hospitalier Universitaire, Nantes, France
| | - Eduard Ayuso
- INSERM UMR1089, University of Nantes, Centre Hospitalier Universitaire, Nantes, France
| | - Dirk Grimm
- Department of Infectious Diseases/Virology, Heidelberg University Hospital, Cluster of Excellence CellNetworks, Heidelberg, Germany
- BioQuant Center, University of Heidelberg, Heidelberg, Germany
- German Center for Infection Research, Partner Site Heidelberg, Heidelberg, Germany
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34
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Bennett A, Patel S, Mietzsch M, Jose A, Lins-Austin B, Yu JC, Bothner B, McKenna R, Agbandje-McKenna M. Thermal Stability as a Determinant of AAV Serotype Identity. Mol Ther Methods Clin Dev 2017; 6:171-182. [PMID: 28828392 PMCID: PMC5552060 DOI: 10.1016/j.omtm.2017.07.003] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2017] [Accepted: 07/18/2017] [Indexed: 12/11/2022]
Abstract
Currently, there are over 150 ongoing clinical trials utilizing adeno-associated viruses (AAVs) to target various genetic diseases, including hemophilia (AAV2 and AAV8), congenital heart failure (AAV1 and AAV6), cystic fibrosis (AAV2), rheumatoid arthritis (AAV2), and Batten disease (AAVrh.10). Prior to patient administration, AAV vectors must have their serotype, concentration, purity, and stability confirmed. Here, we report the application of differential scanning fluorimetry (DSF) as a good manufacturing practice (GMP) capable of determining the melting temperature (Tm) for AAV serotype identification. This is a simple, rapid, cost effective, and robust method utilizing small amounts of purified AAV capsids (∼25 μL of ∼1011 particles). AAV1-9 and AAVrh.10 exhibit specific Tms in buffer formulations commonly used in clinical trials. Notably, AAV2 and AAV3, which are the least stable, have varied Tms, whereas AAV5, the most stable, has a narrow Tm range in the different buffers, respectively. Vector stability was dictated by VP3 only, specifically, the ratio of basic/acidic amino acids, and was independent of VP1 and VP2 content or the genome packaged. Furthermore, stability of recombinant AAVs differing by a single basic or acidic amino acid residue are distinguishable. Hence, AAV DSF profiles can serve as a robust method for serotype identification of clinical vectors.
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Affiliation(s)
- Antonette Bennett
- Department of Biochemistry and Molecular Biology, Center for Structural Biology, The McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Saajan Patel
- Department of Biochemistry and Molecular Biology, Center for Structural Biology, The McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Mario Mietzsch
- Department of Biochemistry and Molecular Biology, Center for Structural Biology, The McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Ariana Jose
- Department of Biochemistry and Molecular Biology, Center for Structural Biology, The McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Bridget Lins-Austin
- Department of Biochemistry and Molecular Biology, Center for Structural Biology, The McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Jennifer C. Yu
- Department of Biochemistry and Molecular Biology, Center for Structural Biology, The McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Brian Bothner
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59715, USA
| | - Robert McKenna
- Department of Biochemistry and Molecular Biology, Center for Structural Biology, The McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Mavis Agbandje-McKenna
- Department of Biochemistry and Molecular Biology, Center for Structural Biology, The McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, FL 32610, USA
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Kondratov O, Marsic D, Crosson SM, Mendez-Gomez HR, Moskalenko O, Mietzsch M, Heilbronn R, Allison JR, Green KB, Agbandje-McKenna M, Zolotukhin S. Direct Head-to-Head Evaluation of Recombinant Adeno-associated Viral Vectors Manufactured in Human versus Insect Cells. Mol Ther 2017; 25:2661-2675. [PMID: 28890324 DOI: 10.1016/j.ymthe.2017.08.003] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 07/19/2017] [Accepted: 08/07/2017] [Indexed: 10/19/2022] Open
Abstract
The major drawback of the Baculovirus/Sf9 system for recombinant adeno-associated viral (rAAV) manufacturing is that most of the Bac-derived rAAV vector serotypes, with few exceptions, demonstrate altered capsid compositions and lower biological potencies. Here, we describe a new insect cell-based production platform utilizing attenuated Kozak sequence and a leaky ribosome scanning to achieve a serotype-specific modulation of AAV capsid proteins stoichiometry. By way of example, rAAV5 and rAAV9 were produced and comprehensively characterized side by side with HEK293-derived vectors. A mass spectrometry analysis documented a 3-fold increase in both viral protein (VP)1 and VP2 capsid protein content compared with human cell-derived vectors. Furthermore, we conducted an extensive analysis of encapsidated single-stranded viral DNA using next-generation sequencing and show a 6-fold reduction in collaterally packaged contaminating DNA for rAAV5 produced in insect cells. Consequently, the re-designed rAAVs demonstrated significantly higher biological potencies, even in a comparison with HEK293-manufactured rAAVs mediating, in the case of rAAV5, 4-fold higher transduction of brain tissues in mice. Thus, the described system yields rAAV vectors of superior infectivity and higher genetic identity providing a scalable platform for good manufacturing practice (GMP)-grade vector production.
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Affiliation(s)
- Oleksandr Kondratov
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Damien Marsic
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Sean M Crosson
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Hector R Mendez-Gomez
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Oleksandr Moskalenko
- UFIT Research Computing, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Mario Mietzsch
- Department of Biochemistry and Molecular Biology, Center for Structural Biology, University of Florida College of Medicine, Gainesville, FL 32610, USA; Institute of Virology, Campus Benjamin Franklin, Charité Medical School, Berlin, Germany
| | - Regine Heilbronn
- Institute of Virology, Campus Benjamin Franklin, Charité Medical School, Berlin, Germany
| | | | - Kari B Green
- Department of Chemistry, University of Florida, Gainesville, FL, USA
| | - Mavis Agbandje-McKenna
- Department of Biochemistry and Molecular Biology, Center for Structural Biology, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Sergei Zolotukhin
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA.
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36
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Mietzsch M, Hering H, Hammer EM, Agbandje-McKenna M, Zolotukhin S, Heilbronn R. OneBac 2.0: Sf9 Cell Lines for Production of AAV1, AAV2, and AAV8 Vectors with Minimal Encapsidation of Foreign DNA. Hum Gene Ther Methods 2017; 28:15-22. [PMID: 28125901 DOI: 10.1089/hgtb.2016.164] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Recombinant adeno-associated viral (rAAV) vectors for human gene therapy require efficient and economical production methods to keep pace with the rapidly increasing clinical demand. In addition, the manufacturing process must ensure high vector quality and biological safety. The OneBac system offers easily scalable rAAV vector production in insect Sf9-derived AAV rep/cap-expressing producer cell lines infected with a single baculovirus that carries the rAAV backbone. For most AAV serotypes high burst sizes per cell were achieved, combined with high infectivity rates. OneBac 2.0 represents a 2-fold advancement: First, enhanced VP1 proportions in AAV5 capsids lead to vastly increased per-particle infectivity rates. Second, collateral packaging of foreign DNA is suppressed by removal of the Rep-binding element (RBE). In this study we show that this advancement of AAV5 packaging can be translated to OneBac 2.0-derived packaging systems for alternative AAV serotypes. By removal of the RBE, collateral packaging of nonvector DNA was drastically reduced in all newly tested serotypes (AAV1, AAV2, and AAV8). However, the splicing-based strategy to enhance VP1 expression in order to increase AAV5 infectivity hardly improved infectivity rates of AAV-1, -2, or -8 compared with the original OneBac cell lines. Our results emphasize that OneBac 2.0 represents an advancement for scalable, high-titer production of various AAV serotypes, leading to AAV particles with minimal packaging of foreign DNA.
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Affiliation(s)
- Mario Mietzsch
- 1 Institute of Virology, Campus Benjamin Franklin, Charité Medical School , Berlin, Germany .,2 Department of Biochemistry and Molecular Biology, University of Florida College of Medicine , Gainesville, FL
| | - Henrik Hering
- 1 Institute of Virology, Campus Benjamin Franklin, Charité Medical School , Berlin, Germany
| | - Eva-Maria Hammer
- 1 Institute of Virology, Campus Benjamin Franklin, Charité Medical School , Berlin, Germany
| | - Mavis Agbandje-McKenna
- 2 Department of Biochemistry and Molecular Biology, University of Florida College of Medicine , Gainesville, FL
| | - Sergei Zolotukhin
- 3 Department of Pediatrics, University of Florida College of Medicine , Gainesville, FL
| | - Regine Heilbronn
- 1 Institute of Virology, Campus Benjamin Franklin, Charité Medical School , Berlin, Germany
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Adamson-Small L, Potter M, Byrne BJ, Clément N. Sodium Chloride Enhances Recombinant Adeno-Associated Virus Production in a Serum-Free Suspension Manufacturing Platform Using the Herpes Simplex Virus System. Hum Gene Ther Methods 2017; 28:1-14. [PMID: 28117600 PMCID: PMC5346630 DOI: 10.1089/hgtb.2016.151] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The increase in effective treatments using recombinant adeno-associated viral (rAAV) vectors has underscored the importance of scalable, high-yield manufacturing methods. Previous work from this group reported the use of recombinant herpes simplex virus type 1 (rHSV) vectors to produce rAAV in adherent HEK293 cells, demonstrating the capacity of this system and quality of the product generated. Here we report production and optimization of rAAV using the rHSV system in suspension HEK293 cells (Expi293F) grown in serum and animal component-free medium. Through adjustment of salt concentration in the medium and optimization of infection conditions, titers greater than 1 × 1014 vector genomes per liter (VG/liter) were observed in purified rAAV stocks produced in Expi293F cells. Furthermore, this system allowed for high-titer production of multiple rAAV serotypes (2, 5, and 9) as well as multiple transgenes (green fluorescent protein and acid α-glucosidase). A proportional increase in vector production was observed as this method was scaled, with a final 3-liter shaker flask production yielding an excess of 1 × 1015 VG in crude cell harvests and an average of 3.5 × 1014 total VG of purified rAAV9 material, resulting in greater than 1 × 105 VG/cell. These results support the use of this rHSV-based rAAV production method for large-scale preclinical and clinical vector production.
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Affiliation(s)
- Laura Adamson-Small
- Department of Pediatrics, Powell Gene Therapy Center, University of Florida , Gainesville, FL
| | - Mark Potter
- Department of Pediatrics, Powell Gene Therapy Center, University of Florida , Gainesville, FL
| | - Barry J Byrne
- Department of Pediatrics, Powell Gene Therapy Center, University of Florida , Gainesville, FL
| | - Nathalie Clément
- Department of Pediatrics, Powell Gene Therapy Center, University of Florida , Gainesville, FL
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38
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Reid CA, Boye SL, Hauswirth WW, Lipinski DM. miRNA-mediated post-transcriptional silencing of transgenes leads to increased adeno-associated viral vector yield and targeting specificity. Gene Ther 2017; 24:462-469. [DOI: 10.1038/gt.2017.50] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2017] [Revised: 06/05/2017] [Accepted: 06/08/2017] [Indexed: 12/21/2022]
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Bennett A, Mietzsch M, Agbandje-McKenna M. Understanding capsid assembly and genome packaging for adeno-associated viruses. Future Virol 2017; 12:283-297. [PMID: 36776482 PMCID: PMC9910337 DOI: 10.2217/fvl-2017-0011] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Adeno-associated viruses (AAVs) are promising therapeutic viral vectors. Their capsid is assembled from viral proteins VP1, VP2 and VP3, aided by an assembly-activating protein, followed by replication protein mediated packaging of their 4.7-kb genome with inverted terminal repeats as packaging signals. To aid improvement of AAV vectors, knowledge of viral determinants of successful capsid assembly and genome packaging is important. We review the current knowledge of these two processes and efforts to overcome limited DNA packaging capacity and limit the packaging of unwanted foreign DNA in vector development. Residues involved in essential capsid assembly and genome packaging interactions cannot be manipulated in vector engineering. This information thus aids strategies to improve vector production and to increase AAV packaging capacity toward improved efficacy of this vector system.
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Affiliation(s)
- Antonette Bennett
- Department of Biochemistry & Molecular Biology, Center for Structure Biology, McKnight Brain Institute, University of Florida, Gainesville, FL 32610-0245, USA
| | - Mario Mietzsch
- Department of Biochemistry & Molecular Biology, Center for Structure Biology, McKnight Brain Institute, University of Florida, Gainesville, FL 32610-0245, USA
| | - Mavis Agbandje-McKenna
- Department of Biochemistry & Molecular Biology, Center for Structure Biology, McKnight Brain Institute, University of Florida, Gainesville, FL 32610-0245, USA,Author for correspondence: Tel.: +1 352 294 8393;
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40
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Kotin RM, Snyder RO. Manufacturing Clinical Grade Recombinant Adeno-Associated Virus Using Invertebrate Cell Lines. Hum Gene Ther 2017; 28:350-360. [DOI: 10.1089/hum.2017.042] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Robert M. Kotin
- Gene Therapy Center, University of Massachusetts Medical School, Worcester, Massachusetts
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41
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Ertl HCJ, High KA. Impact of AAV Capsid-Specific T-Cell Responses on Design and Outcome of Clinical Gene Transfer Trials with Recombinant Adeno-Associated Viral Vectors: An Evolving Controversy. Hum Gene Ther 2016; 28:328-337. [PMID: 28042943 DOI: 10.1089/hum.2016.172] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Recombinant adenovirus-associated (rAAV) vectors due to their ease of construction, wide tissue tropism, and lack of pathogenicity remain at the forefront for long-term gene replacement therapy. In spite of very encouraging preclinical results, clinical trials were initially unsuccessful; expression of the rAAV vector-delivered therapeutic protein was transient. Loss of expression was linked to an expansion of AAV capsid-specific T-cell responses, leading to the hypothesis that rAAV vectors recall pre-existing memory T cells that had been induced by natural infections with AAV together with a helper virus. Although this was hotly debated at first, AAV capsid-specific T-cell responses were observed in several gene transfer trials that used high doses of rAAV vectors. Subsequent trials designed to circumvent these T-cell responses through the use of immunosuppressive drugs, rAAV vectors based on rare serotypes, or modified to allow for therapeutic levels of the transgene product at low, non-immunogenic vector doses are now successful in correcting debilitating diseases.
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42
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Adamson-Small L, Potter M, Falk DJ, Cleaver B, Byrne BJ, Clément N. A scalable method for the production of high-titer and high-quality adeno-associated type 9 vectors using the HSV platform. Mol Ther Methods Clin Dev 2016; 3:16031. [PMID: 27222839 PMCID: PMC4863725 DOI: 10.1038/mtm.2016.31] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 03/28/2016] [Indexed: 01/04/2023]
Abstract
Recombinant adeno-associated vectors based on serotype 9 (rAAV9) have demonstrated highly effective gene transfer in multiple animal models of muscular dystrophies and other neurological indications. Current limitations in vector production and purification have hampered widespread implementation of clinical candidate vectors, particularly when systemic administration is considered. In this study, we describe a complete herpes simplex virus (HSV)-based production and purification process capable of generating greater than 1 × 10(14) rAAV9 vector genomes per 10-layer CellSTACK of HEK 293 producer cells, or greater than 1 × 10(5) vector genome per cell, in a final, fully purified product. This represents a 5- to 10-fold increase over transfection-based methods. In addition, rAAV vectors produced by this method demonstrated improved biological characteristics when compared to transfection-based production, including increased infectivity as shown by higher transducing unit-to-vector genome ratios and decreased total capsid protein amounts, shown by lower empty-to-full ratios. Together, this data establishes a significant improvement in both rAAV9 yields and vector quality. Further, the method can be readily adapted to large-scale good laboratory practice (GLP) and good manufacturing practice (GMP) production of rAAV9 vectors to enable preclinical and clinical studies and provide a platform to build on toward late-phases and commercial production.
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Affiliation(s)
- Laura Adamson-Small
- Department of Pediatrics, Powell Gene Therapy Center, University of Florida, Gainesville, Florida, USA
| | - Mark Potter
- Department of Pediatrics, Powell Gene Therapy Center, University of Florida, Gainesville, Florida, USA
| | - Darin J Falk
- Department of Pediatrics, Child Health Research Institute, University of Florida, Florida, USA
| | - Brian Cleaver
- Department of Pediatrics, Powell Gene Therapy Center, University of Florida, Gainesville, Florida, USA
| | - Barry J Byrne
- Department of Pediatrics, Powell Gene Therapy Center, University of Florida, Gainesville, Florida, USA
| | - Nathalie Clément
- Department of Pediatrics, Powell Gene Therapy Center, University of Florida, Gainesville, Florida, USA
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