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Maguire AM, Bennett J, Aleman EM, Leroy BP, Aleman TS. Clinical Perspective: Treating RPE65-Associated Retinal Dystrophy. Mol Ther 2021; 29:442-463. [PMID: 33278565 PMCID: PMC7854308 DOI: 10.1016/j.ymthe.2020.11.029] [Citation(s) in RCA: 77] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 11/16/2020] [Accepted: 11/25/2020] [Indexed: 12/25/2022] Open
Abstract
Until recently, there was no approved treatment for a retinal degenerative disease. Subretinal injection of a recombinant adeno-associated virus (AAV) delivering the normal copy of the human RPE65 cDNA led to reversal of blindness first in animal models and then in humans. This led to the first US Food and Drug Administration (FDA)-approved gene therapy product for a genetic disease, voretigene neparvovec-rzyl (Luxturna). Luxturna was then approved by the European Medicines Association and is now available in the US through Spark Therapeutics and worldwide through Novartis. Not only has treatment with Luxturna changed the lives of people previously destined to live a life of blindness, but it has fueled interest in developing additional gene therapy reagents targeting numerous other genetic forms of inherited retinal disease. This review describes many of the considerations for administration of Luxturna and describes how lessons from experience with Luxturna could lead to additional gene-based treatments of blindness.
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Affiliation(s)
- Albert M Maguire
- Center for Advanced Retinal and Ocular Therapeutics (CAROT), Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA; The Children's Hospital of Philadelphia (CHOP), Philadelphia, PA, USA
| | - Jean Bennett
- Center for Advanced Retinal and Ocular Therapeutics (CAROT), Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA; The Children's Hospital of Philadelphia (CHOP), Philadelphia, PA, USA
| | - Elena M Aleman
- Center for Advanced Retinal and Ocular Therapeutics (CAROT), Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Bart P Leroy
- Center for Advanced Retinal and Ocular Therapeutics (CAROT), Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA; Department of Ophthalmology and Center for Medical Genetics Ghent, Ghent University Hospital, Ghent, Belgium
| | - Tomas S Aleman
- Center for Advanced Retinal and Ocular Therapeutics (CAROT), Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA; The Children's Hospital of Philadelphia (CHOP), Philadelphia, PA, USA.
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Annear MJ, Mowat FM, Occelli LM, Smith AJ, Curran PG, Bainbridge JW, Ali RR, Petersen-Jones SM. A Comprehensive Study of the Retinal Phenotype of Rpe65-Deficient Dogs. Cells 2021; 10:cells10010115. [PMID: 33435495 PMCID: PMC7827248 DOI: 10.3390/cells10010115] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Revised: 01/04/2021] [Accepted: 01/06/2021] [Indexed: 01/09/2023] Open
Abstract
The Rpe65-deficient dog has been important for development of translational therapies of Leber congenital amaurosis type 2 (LCA2). The purpose of this study was to provide a comprehensive report of the natural history of retinal changes in this dog model. Rpe65-deficient dogs from 2 months to 10 years of age were assessed by fundus imaging, electroretinography (ERG) and vision testing (VT). Changes in retinal layer thickness were assessed by optical coherence tomography and on plastic retinal sections. ERG showed marked loss of retinal sensitivity, with amplitudes declining with age. Retinal thinning initially developed in the area centralis, with a slower thinning of the outer retina in other areas starting with the inferior retina. VT showed that dogs of all ages performed well in bright light, while at lower light levels they were blind. Retinal pigment epithelial (RPE) inclusions developed and in younger dogs and increased in size with age. The loss of photoreceptors was mirrored by a decline in ERG amplitudes. The slow degeneration meant that sufficient photoreceptors, albeit very desensitized, remained to allow for residual bright light vision in older dogs. This study shows the natural history of the Rpe65-deficient dog model of LCA2.
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Affiliation(s)
- Matthew J Annear
- Department of Small Animal Clinical Sciences, Michigan State University, East Lansing, MI 48824, USA; (M.J.A.); (F.M.M.); (L.M.O.)
| | - Freya M Mowat
- Department of Small Animal Clinical Sciences, Michigan State University, East Lansing, MI 48824, USA; (M.J.A.); (F.M.M.); (L.M.O.)
| | - Laurence M Occelli
- Department of Small Animal Clinical Sciences, Michigan State University, East Lansing, MI 48824, USA; (M.J.A.); (F.M.M.); (L.M.O.)
| | - Alexander J Smith
- Department of Genetics, UCL Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, UK; (A.J.S.); (J.W.B.); (R.R.A.)
| | - Paul G Curran
- Center for Statistical Consulting, Michigan State University, East Lansing, MI 48824, USA;
| | - James W Bainbridge
- Department of Genetics, UCL Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, UK; (A.J.S.); (J.W.B.); (R.R.A.)
- NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, City Road, London EC1V 2PD, UK
| | - Robin R Ali
- Department of Genetics, UCL Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, UK; (A.J.S.); (J.W.B.); (R.R.A.)
- NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, City Road, London EC1V 2PD, UK
| | - Simon M Petersen-Jones
- Department of Small Animal Clinical Sciences, Michigan State University, East Lansing, MI 48824, USA; (M.J.A.); (F.M.M.); (L.M.O.)
- Correspondence:
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103
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Xu D, Khan MA, Ho AC. Creating an Ocular Biofactory: Surgical Approaches in Gene Therapy for Acquired Retinal Diseases. Asia Pac J Ophthalmol (Phila) 2021; 10:5-11. [PMID: 33399391 DOI: 10.1097/apo.0000000000000362] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
ABSTRACT Gene therapy offers the potential to treat inherited retinal disorders and deliver sustained therapy for acquired retinal diseases. In the latter case, host cells can be harnessed to produce non-native proteins that have beneficial properties, such as antivascular endothelial growth factor activity, transforming the eye into an ocular "biofactory." Several gene therapy programs have entered clinical testing for delivery to the vitreous, subretinal, and suprachoroidal space. Improved viral vectors and refined surgical techniques are critical to successful delivery of therapeutic products to the target tissue. In this review, we discuss the development of gene therapy products aimed at acquired retinal diseases and the surgical techniques utilized to achieve targeted delivery.
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Affiliation(s)
- David Xu
- Retina Service, Wills Eye Hospital, Philadelphia, PA
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104
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Marcos LF, Wilson SL, Roach P. Tissue engineering of the retina: from organoids to microfluidic chips. J Tissue Eng 2021; 12:20417314211059876. [PMID: 34917332 PMCID: PMC8669127 DOI: 10.1177/20417314211059876] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 10/28/2021] [Indexed: 12/29/2022] Open
Abstract
Despite advancements in tissue engineering, challenges remain for fabricating functional tissues that incorporate essential features including vasculature and complex cellular organisation. Monitoring of engineered tissues also raises difficulties, particularly when cell population maturity is inherent to function. Microfluidic, or lab-on-a-chip, platforms address the complexity issues of conventional 3D models regarding cell numbers and functional connectivity. Regulation of biochemical/biomechanical conditions can create dynamic structures, providing microenvironments that permit tissue formation while quantifying biological processes at a single cell level. Retinal organoids provide relevant cell numbers to mimic in vivo spatiotemporal development, where conventional culture approaches fail. Modern bio-fabrication techniques allow for retinal organoids to be combined with microfluidic devices to create anato-physiologically accurate structures or 'retina-on-a-chip' devices that could revolution ocular sciences. Here we present a focussed review of retinal tissue engineering, examining the challenges and how some of these have been overcome using organoids, microfluidics, and bioprinting technologies.
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Affiliation(s)
- Luis F Marcos
- Department of Chemistry, School of Science, Loughborough University, Leicestershire, UK
| | - Samantha L Wilson
- Centre for Biological Engineering, School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Leicestershire, UK
| | - Paul Roach
- Department of Chemistry, School of Science, Loughborough University, Leicestershire, UK
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105
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Rodríguez-Márquez E, Meumann N, Büning H. Adeno-associated virus (AAV) capsid engineering in liver-directed gene therapy. Expert Opin Biol Ther 2020; 21:749-766. [PMID: 33331201 DOI: 10.1080/14712598.2021.1865303] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Introduction: Gene therapy clinical trials with adeno-associated virus (AAV) vectors report impressive clinical efficacy data. Nevertheless, challenges have become apparent, such as the need for high vector doses and the induction of anti-AAV immune responses that cause the loss of vector-transduced hepatocytes. This fostered research focusing on development of next-generation AAV vectors capable of dealing with these hurdles.Areas Covered: While both the viral vector genome and the capsid are subjects to engineering, this review focuses on the latter. Specifically, we summarize the principles of capsid engineering strategies, and describe developments and applications of engineered capsid variants for liver-directed gene therapy.Expert Opinion: Capsid engineering is a promising strategy to significantly improve efficacy of the AAV vector system in clinical application. Reduction in vector dose will further improve vector safety, lower the risk of host immune responses and the cost of manufacturing. Capsid engineering is also expected to result in AAV vectors applicable to patients with preexisting immunity toward natural AAV serotypes.
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Affiliation(s)
- Esther Rodríguez-Márquez
- Universidad Autónoma De Madrid, Madrid, Spain.,Institute of Experimental Hematology, Hannover Medical School, Hannover, Germany.,REBIRTH Research Center for Translational Regenerative Medicine, Hannover Medical School, Hannover, Germany
| | - Nadja Meumann
- Institute of Experimental Hematology, Hannover Medical School, Hannover, Germany.,REBIRTH Research Center for Translational Regenerative Medicine, Hannover Medical School, Hannover, Germany
| | - Hildegard Büning
- Institute of Experimental Hematology, Hannover Medical School, Hannover, Germany.,REBIRTH Research Center for Translational Regenerative Medicine, Hannover Medical School, Hannover, Germany.,Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany.,German Center for Infection Research (DZIF, Partner Site Hannover-Braunschweig, Germany
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106
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Mendell JR, Al-Zaidy SA, Rodino-Klapac LR, Goodspeed K, Gray SJ, Kay CN, Boye SL, Boye SE, George LA, Salabarria S, Corti M, Byrne BJ, Tremblay JP. Current Clinical Applications of In Vivo Gene Therapy with AAVs. Mol Ther 2020; 29:464-488. [PMID: 33309881 PMCID: PMC7854298 DOI: 10.1016/j.ymthe.2020.12.007] [Citation(s) in RCA: 365] [Impact Index Per Article: 91.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 11/16/2020] [Accepted: 12/05/2020] [Indexed: 02/07/2023] Open
Abstract
Hereditary diseases are caused by mutations in genes, and more than 7,000 rare diseases affect over 30 million Americans. For more than 30 years, hundreds of researchers have maintained that genetic modifications would provide effective treatments for many inherited human diseases, offering durable and possibly curative clinical benefit with a single treatment. This review is limited to gene therapy using adeno-associated virus (AAV) because the gene delivered by this vector does not integrate into the patient genome and has a low immunogenicity. There are now five treatments approved for commercialization and currently available, i.e., Luxturna, Zolgensma, the two chimeric antigen receptor T cell (CAR-T) therapies (Yescarta and Kymriah), and Strimvelis (the gammaretrovirus approved for adenosine deaminase-severe combined immunodeficiency [ADA-SCID] in Europe). Dozens of other treatments are under clinical trials. The review article presents a broad overview of the field of therapy by in vivo gene transfer. We review gene therapy for neuromuscular disorders (spinal muscular atrophy [SMA]; Duchenne muscular dystrophy [DMD]; X-linked myotubular myopathy [XLMTM]; and diseases of the central nervous system, including Alzheimer’s disease, Parkinson’s disease, Canavan disease, aromatic l-amino acid decarboxylase [AADC] deficiency, and giant axonal neuropathy), ocular disorders (Leber congenital amaurosis, age-related macular degeneration [AMD], choroideremia, achromatopsia, retinitis pigmentosa, and X-linked retinoschisis), the bleeding disorder hemophilia, and lysosomal storage disorders.
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Affiliation(s)
- Jerry R Mendell
- Center of Gene Therapy, Abigail Wexner Research Institute, Nationwide Children's Hospital, Columbus, OH, USA; Department of Pediatrics and Neurology, The Ohio State University, Columbus, OH, USA
| | | | | | - Kimberly Goodspeed
- Department of Pediatrics, UT Southwestern Medical Center, Dallas, TX, USA
| | - Steven J Gray
- Department of Pediatrics, UT Southwestern Medical Center, Dallas, TX, USA
| | | | - Sanford L Boye
- Department of Pediatrics, Powell Gene Therapy Center, University of Florida, Gainesville, FL, USA
| | - Shannon E Boye
- Division of Cellular and Molecular Therapeutics, University of Florida, Gainesville, FL, USA
| | - Lindsey A George
- Division of Hematology and the Perelman Center for Cellular and Molecular Therapeutics, Philadelphia, PA, USA; Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Stephanie Salabarria
- Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Manuela Corti
- Department of Pediatrics, College of Medicine, University of Florida, Gainesville, FL, USA; Powell Gene Therapy Center, University of Florida, Gainesville, FL, USA
| | - Barry J Byrne
- Department of Pediatrics, College of Medicine, University of Florida, Gainesville, FL, USA; Powell Gene Therapy Center, University of Florida, Gainesville, FL, USA
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107
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Eggshell Membrane/Gellan Gum Composite Hydrogels with Increased Degradability, Biocompatibility, and Anti-Swelling Properties for Effective Regeneration of Retinal Pigment Epithelium. Polymers (Basel) 2020; 12:polym12122941. [PMID: 33317040 PMCID: PMC7764595 DOI: 10.3390/polym12122941] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 12/07/2020] [Accepted: 12/08/2020] [Indexed: 12/29/2022] Open
Abstract
A gellan gum (GG) hydrogel must demonstrate a number of critical qualities—low viscosity, degradability, desirable mechanical properties, anti-swelling properties, and biocompatibility—in order to be regarded as suitable for retinal pigment epithelium (RPE) regeneration. In this study, we investigated whether the application of an eggshell membrane (ESM) to a GG hydrogel improved these critical attributes. The crosslinking of the ESM/GG hydrogels was most effectively reduced, when a 4 w/v% ESM was used, leading to a 40% less viscosity and a 30% higher degradation efficiency than a pure GG hydrogel. The compressive moduli of the ESM/GG hydrogels were maintained, as the smaller pores formed by the addition of the ESM compensated for the slightly weakened mechanical properties of the ESM/GG hydrogels. Meanwhile, due to the relatively low hydrophilicity of ESM, a 4 w/v% ESM enabled an ESM/GG hydrogel to swell 30% less than a pure GG hydrogel. Finally, the similarity in components between the ESM and RPE cells facilitated the proliferation of the latter without any significant cytotoxicity.
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108
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Padhy SK, Takkar B, Narayanan R, Venkatesh P, Jalali S. Voretigene Neparvovec and Gene Therapy for Leber's Congenital Amaurosis: Review of Evidence to Date. APPLICATION OF CLINICAL GENETICS 2020; 13:179-208. [PMID: 33268999 PMCID: PMC7701157 DOI: 10.2147/tacg.s230720] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 11/06/2020] [Indexed: 12/13/2022]
Abstract
Gene therapy has now evolved as the upcoming modality for management of many disorders, both inheritable and non-inheritable. Knowledge of genetics pertaining to a disease has therefore become paramount for physicians across most specialities. Inheritable retinal dystrophies (IRDs) are notorious for progressive and relentless vision loss, frequently culminating in complete blindness in both eyes. Leber’s congenital amaurosis (LCA) is a typical example of an IRD that manifests very early in childhood. Research in gene therapy has led to the development and approval of voretigene neparvovec (VN) for use in patients of LCA with a deficient biallelic RPE65 gene. The procedure involves delivery of a recombinant virus vector that carries the RPE65 gene in the subretinal space. This comprehensive review reports the evidence thus far in support of gene therapy for LCA. We explore and compare the various gene targets including but not limited to RPE65, and discuss the choice of vector and method for ocular delivery. The review details the evolution of gene therapy with VN in a phased manner, concluding with the challenges that lie ahead for its translation for use in communities that differ much both genetically and economically.
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Affiliation(s)
- Srikanta Kumar Padhy
- Vitreoretina and Uveitis Services, L V Prasad Eye Institute, Mithu Tulsi Chanrai Campus, Bhubaneswar, India
| | - Brijesh Takkar
- Srimati Kanuri Santhamma Center for Vitreoretinal Diseases, Kallam Anji Reddy Campus, L.V. Prasad Eye Institute, Hyderabad, India.,Center of Excellence for Rare Eye Diseases, Kallam Anji Reddy Campus, L V Prasad Eye Institute, Hyderabad, India
| | - Raja Narayanan
- Srimati Kanuri Santhamma Center for Vitreoretinal Diseases, Kallam Anji Reddy Campus, L.V. Prasad Eye Institute, Hyderabad, India
| | - Pradeep Venkatesh
- Dr RP Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Subhadra Jalali
- Srimati Kanuri Santhamma Center for Vitreoretinal Diseases, Kallam Anji Reddy Campus, L.V. Prasad Eye Institute, Hyderabad, India.,Jasti V. Ramanamma Childrens' Eye Care Centre, Kallam Anji Reddy Campus, L V Prasad Eye Institute, Hyderabad, India
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109
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Kim CH, Oliver C, Dar H, Drissi H, Presciutti SM. AAV6 as an effective gene delivery vector for prolonged transgene expression in intervertebral disc cells in vivo. Genes Dis 2020; 9:1074-1085. [PMID: 35685478 PMCID: PMC9170577 DOI: 10.1016/j.gendis.2020.12.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Revised: 12/07/2020] [Accepted: 12/22/2020] [Indexed: 12/05/2022] Open
Abstract
Intervertebral disc degeneration is the main contributor to low back pain, now the leading cause of disability worldwide. Gene transfer, either in a therapeutic attempt or in basic research to understand the mechanisms of disc degeneration, is a fascinating and promising tool to manipulate the complex physiology of the disc. Viral vectors based on the adeno-associated virus (AAV) have emerged as powerful transgene delivery vehicles yet a systematic investigation into their respective tropism, transduction efficiency, and relative toxicity have not yet been performed in the disc in vivo. Herein, we used in vivo bioluminescence imaging to systematically compare multiple AAV serotypes, injection volumes, titers, promoters, and luciferase reporters to determine which result in high transduction efficiency of murine nucleus pulposus (NP) cells in vivo. We find that AAV6 using a CAG promoter to drive transgene expression, delivered into the NP of murine caudal discs at a titer of 1011 GC/mL, provides excellent transduction efficiency/kinetics and low toxicity in vivo. We also show, for the first time, that the transduction of NP cells can be significantly boosted in vivo by the use of small cell permeabilization peptides. Finally, to our knowledge, we are the first to demonstrate the use of optical tissue clearing and three-dimensional lightsheet microscopy in the disc, which was used to visualize fine details of tissue and cell architecture in whole intact discs following AAV6 delivery. Taken together, these data will contribute to the success of using AAV-mediated gene delivery for basic and translational studies of the IVD.
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Affiliation(s)
- Chi Heon Kim
- Department of Orthopaedics, Emory University School of Medicine, Atlanta, GA 30329, USA
- Atlanta Veteran Affairs Medical Center, Decatur, GA 30030, USA
| | - Colleen Oliver
- Department of Orthopaedics, Emory University School of Medicine, Atlanta, GA 30329, USA
- Atlanta Veteran Affairs Medical Center, Decatur, GA 30030, USA
| | - Hamid Dar
- Department of Orthopaedics, Emory University School of Medicine, Atlanta, GA 30329, USA
| | - Hicham Drissi
- Department of Orthopaedics, Emory University School of Medicine, Atlanta, GA 30329, USA
- Atlanta Veteran Affairs Medical Center, Decatur, GA 30030, USA
- Corresponding author. Emory Orthopaedics and Spine Center, 59 Executive Park S NE, Atlanta, GA 30329, USA.
| | - Steven M. Presciutti
- Department of Orthopaedics, Emory University School of Medicine, Atlanta, GA 30329, USA
- Atlanta Veteran Affairs Medical Center, Decatur, GA 30030, USA
- Corresponding author. Emory Orthopaedics and Spine Center, 59 Executive Park S NE, Atlanta, GA 30329, USA.
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Inverse correlation between fatty acid transport protein 4 and vision in Leber congenital amaurosis associated with RPE65 mutation. Proc Natl Acad Sci U S A 2020; 117:32114-32123. [PMID: 33257550 DOI: 10.1073/pnas.2012623117] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Fatty acid transport protein 4 (FATP4), a transmembrane protein in the endoplasmic reticulum (ER), is a recently identified negative regulator of the ER-associated retinal pigment epithelium (RPE)65 isomerase necessary for recycling 11-cis-retinal, the light-sensitive chromophore of both rod and cone opsin visual pigments. The role of FATP4 in the disease progression of retinal dystrophies associated with RPE65 mutations is completely unknown. Here we show that FATP4-deficiency in the RPE results in 2.8-fold and 1.7-fold increase of 11-cis- and 9-cis-retinals, respectively, improving dark-adaptation rates as well as survival and function of rods in the Rpe65 R91W knockin (KI) mouse model of Leber congenital amaurosis (LCA). Degradation of S-opsin in the proteasomes, but not in the lysosomes, was remarkably reduced in the KI mouse retinas lacking FATP4. FATP4-deficiency also significantly rescued S-opsin trafficking and M-opsin solubility in the KI retinas. The number of S-cones in the inferior retinas of 4- or 6-mo-old KI;Fatp4 -/- mice was 7.6- or 13.5-fold greater than those in age-matched KI mice. Degeneration rates of S- and M-cones are negatively correlated with expression levels of FATP4 in the RPE of the KI, KI;Fatp4 +/- , and KI;Fatp4 -/- mice. Moreover, the visual function of S- and M-cones is markedly preserved in the KI;Fatp4 -/- mice, displaying an inverse correlation with the FATP4 expression levels in the RPE of the three mutant lines. These findings establish FATP4 as a promising therapeutic target to improve the visual cycle, as well as survival and function of cones and rods in patients with RPE65 mutations.
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111
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Properties and Therapeutic Implications of an Enigmatic D477G RPE65 Variant Associated with Autosomal Dominant Retinitis Pigmentosa. Genes (Basel) 2020; 11:genes11121420. [PMID: 33261050 PMCID: PMC7760593 DOI: 10.3390/genes11121420] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 11/24/2020] [Accepted: 11/24/2020] [Indexed: 12/22/2022] Open
Abstract
RPE65 isomerase, expressed in the retinal pigmented epithelium (RPE), is an enzymatic component of the retinoid cycle, converting all-trans retinyl ester into 11-cis retinol, and it is essential for vision, because it replenishes the photon capturing 11-cis retinal. To date, almost 200 loss-of-function mutations have been identified within the RPE65 gene causing inherited retinal dystrophies, most notably Leber congenital amaurosis (LCA) and autosomal recessive retinitis pigmentosa (arRP), which are both severe and early onset disease entities. We previously reported a mutation, D477G, co-segregating with the disease in a late-onset form of autosomal dominant RP (adRP) with choroidal involvement; uniquely, it is the only RPE65 variant to be described with a dominant component. Families or individuals with this variant have been encountered in five countries, and a number of subsequent studies have been reported in which the molecular biological and physiological properties of the variant have been studied in further detail, including observations of possible novel functions in addition to reduced RPE65 enzymatic activity. With regard to the latter, a human phase 1b proof-of-concept study has recently been reported in which aspects of remaining vision were improved for up to one year in four of five patients with advanced disease receiving a single one-week oral dose of 9-cis retinaldehyde, which is the first report showing efficacy and safety of an oral therapy for a dominant form of RP. Here, we review data accrued from published studies investigating molecular mechanisms of this unique variant and include hitherto unpublished material on the clinical spectrum of disease encountered in patients with the D477G variant, which, in many cases bears striking similarities to choroideremia.
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112
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Abstract
PURPOSE Choroideremia is an incurable, X-linked, recessive retinal dystrophy caused by loss of function mutations in the CHM gene. It is estimated to affect approximately 1 in 50,000 male patients. It is characterized by progressive degeneration of the retinal pigment epithelium, choroid, and photoreceptors, resulting in visual impairment and blindness. There is an unmet need in choroideremia, because currently, there are no approved treatments available for patients with the disease. METHODS We review the patient journey, societal impact, and emerging treatments for patients with choroideremia. RESULTS Its relative rarity and similarities with other retinal diseases in early years mean that diagnosis of choroideremia can often be delayed. Furthermore, its impact on affected individuals, and wider society, is also likely underestimated. AAV2-mediated gene therapy is an investigational treatment that aims to replace the faulty CHM gene. Early-phase studies reported potentially important visual acuity gains and maintenance of vision in some patients, and a large Phase 3 program is now underway. CONCLUSION Choroideremia is a disease with a significant unmet need. Interventions that can treat progression of the disease and improve visual and functional outcomes have the potential to reduce health care costs and enhance patient quality of life.
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113
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Gao J, Hussain RM, Weng CY. Voretigene Neparvovec in Retinal Diseases: A Review of the Current Clinical Evidence. Clin Ophthalmol 2020; 14:3855-3869. [PMID: 33223822 PMCID: PMC7671481 DOI: 10.2147/opth.s231804] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 10/21/2020] [Indexed: 12/26/2022] Open
Abstract
Subretinal gene therapy trials began with the discovery of RPE65 variants and their association with Leber congenital amaurosis. The RPE65 protein is critical for the normal functioning of the visual phototransduction cascade. RPE65 gene knockout animal models were developed and showed similar diseased phenotypes to their human counterparts. Proof of concept studies were carried out in these animal models using subretinal RPE65 gene replacement therapy, resulting in improvements in various visual function markers including electroretinograms, pupillary light responses, and object avoidance behaviors. Positive results in animal models led to Phase 1 human studies using adeno-associated viral vectors. Results in these initial human studies also showed positive impact on visual function and acceptable safety. A landmark Phase 3 study was then conducted by Spark Therapeutics using a dose of 1.5 x1011 vector genomes after dose-escalation studies confirmed its efficacy and safety. Multi-luminance mobility testing was used to measure the primary efficacy endpoint due to its excellent reliability in detecting the progression of inherited retinal diseases. After the study met its primary endpoint, the Food and Drug Administration approved voretigene neparvovec (Luxturna®) for use in RPE65-associated inherited retinal diseases.
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Affiliation(s)
- Jie Gao
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA
| | | | - Christina Y Weng
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA
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Bucher K, Rodríguez-Bocanegra E, Dauletbekov D, Fischer MD. Immune responses to retinal gene therapy using adeno-associated viral vectors - Implications for treatment success and safety. Prog Retin Eye Res 2020; 83:100915. [PMID: 33069860 DOI: 10.1016/j.preteyeres.2020.100915] [Citation(s) in RCA: 104] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 10/08/2020] [Accepted: 10/10/2020] [Indexed: 02/06/2023]
Abstract
Recombinant adeno-associated virus (AAV) is the leading vector for gene therapy in the retina. As non-pathogenic, non-integrating, replication deficient vector, the recombinant virus efficiently transduces all key retinal cell populations. Successful testing of AAV vectors in clinical trials of inherited retinal diseases led to the recent approval of voretigene neparvovec (Luxturna) for the treatment of RPE65 mutation-associated retinal dystrophies. However, studies applying AAV-mediated retinal gene therapy independently reported intraocular inflammation and/or loss of efficacy after initial functional improvements. Both observations might be explained by targeted removal of transduced cells via anti-viral defence mechanisms. AAV has been shown to activate innate pattern recognition receptors (PRRs) such as toll-like receptor (TLR)-2 and TLR-9 resulting in the release of inflammatory cytokines and type I interferons. The vector can also induce capsid-specific and transgene-specific T cell responses and neutralizing anti-AAV antibodies which both limit the therapeutic effect. However, the target organ of retinal gene therapy, the eye, is known as an immune-privileged site. It is characterized by suppression of inflammation and promotion of immune tolerance which might prevent AAV-induced immune responses. This review evaluates AAV-related immune responses, toxicity and inflammation in studies of retinal gene therapy, identifies influencing variables of these responses and discusses potential strategies to modulate immune reactions to AAV vectors to increase the safety and efficacy of ocular gene therapy.
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Affiliation(s)
- Kirsten Bucher
- University Eye Hospital, Centre for Ophthalmology, University Hospital Tübingen, Tübingen, Germany; Institute for Ophthalmic Research, Centre for Ophthalmology, University Hospital Tübingen, Tübingen, Germany
| | - Eduardo Rodríguez-Bocanegra
- University Eye Hospital, Centre for Ophthalmology, University Hospital Tübingen, Tübingen, Germany; Institute for Ophthalmic Research, Centre for Ophthalmology, University Hospital Tübingen, Tübingen, Germany
| | - Daniyar Dauletbekov
- University Eye Hospital, Centre for Ophthalmology, University Hospital Tübingen, Tübingen, Germany; Institute for Ophthalmic Research, Centre for Ophthalmology, University Hospital Tübingen, Tübingen, Germany
| | - M Dominik Fischer
- University Eye Hospital, Centre for Ophthalmology, University Hospital Tübingen, Tübingen, Germany; Institute for Ophthalmic Research, Centre for Ophthalmology, University Hospital Tübingen, Tübingen, Germany; Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK; Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, UK.
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115
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Buttery PC, Barker RA. Gene and Cell-Based Therapies for Parkinson's Disease: Where Are We? Neurotherapeutics 2020; 17:1539-1562. [PMID: 33128174 PMCID: PMC7598241 DOI: 10.1007/s13311-020-00940-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/28/2020] [Indexed: 02/07/2023] Open
Abstract
Parkinson's disease (PD) is a neurodegenerative disorder that carries large health and socioeconomic burdens. Current therapies for PD are ultimately inadequate, both in terms of symptom control and in modification of disease progression. Deep brain stimulation and infusion therapies are the current mainstay for treatment of motor complications of advanced disease, but these have very significant drawbacks and offer no element of disease modification. In fact, there are currently no agents that are established to modify the course of the disease in clinical use for PD. Gene and cell therapies for PD are now being trialled in the clinic. These treatments are diverse and may have a range of niches in the management of PD. They hold great promise for improved treatment of symptoms as well as possibly slowing progression of the disease in the right patient group. Here, we review the current state of the art for these therapies and look to future strategies in this fast-moving field.
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Affiliation(s)
- Philip C Buttery
- Cambridge Institute for Medical Research, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, CB2 0XY, Cambridge, UK.
- Department of Clinical Neurosciences, University of Cambridge, Cambridge Biomedical Campus, Hills Road, CB2 0QQ, Cambridge, UK.
| | - Roger A Barker
- Department of Clinical Neurosciences, University of Cambridge, Cambridge Biomedical Campus, Hills Road, CB2 0QQ, Cambridge, UK.
- John van Geest Centre for Brain Repair, E.D. Adrian Building, Forvie Site, Robinson Way, CB2 0PY, Cambridge, UK.
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Straňák Z, Kousal B, Ardan T, Veith M. Innovative strategies for treating retinal diseases. ACTA ACUST UNITED AC 2020; 75:287-295. [PMID: 32911944 DOI: 10.31348/2019/6/1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE The aim of this comprehensive paper is to acquaint the readers with innovative approaches in the treatment of retinal diseases, which could in the coming years to get into clinical practice. Retinal prostheses, retinal pigment epithelial (RPE) transplantation, gene therapy and optogenetics will be described in this paper. METHODOLOGY Describing the basic characteristics and mechanisms of different types of therapy and subsequently literary minireview clarifying the current state of knowledge in the area. RESULTS Retinal prostheses, RPE transplantation, gene therapy and optogenetics offer yet unexplored possibilities and are considered as the future of treatment of retinal diseases where classical pharmacotherapy or surgical treatment are no longer sufficient. However, all these methods challenge not only in the innovative technical implementation itself, but also for the ethical, administrative and economic demands. CONCLUSION There will be certainly interesting development in the treatment of retinal diseases, but it is not possible to fully estimate which modality of treatment will be dominant in the future.
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Rambhai HK, Ashby FJ, Qing K, Srivastava A. Role of Essential Metal Ions in AAV Vector-Mediated Transduction. Mol Ther Methods Clin Dev 2020; 18:159-166. [PMID: 32637447 PMCID: PMC7321778 DOI: 10.1016/j.omtm.2020.05.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 05/19/2020] [Indexed: 12/30/2022]
Abstract
Metal elements are essential components of approximately half of all cellular proteins, and approximately one-third of all known enzymes thus far are metalloenzymes. Several cellular proteins and enzymes undoubtedly impact the transduction efficiency of recombinant adeno-associated virus (AAV) vectors, but the precise role of metal ions in this process has not been studied in detail. In the present studies, we systematically evaluated the effects of all 10 essential metal ions (calcium, cobalt, copper, iron, magnesium, manganese, molybdenum, potassium, sodium, and zinc) on the transduction efficiency of AAV vectors. We report herein that five essential metal ions (iron, magnesium, manganese, molybdenum, and sodium) had little to no effect, and calcium strongly inhibited the transduction efficiency of AAV2 vectors. Whereas copper and potassium increased the transduction efficiency by ∼5-fold and ∼2-fold, respectively, at low concentrations, both essential metals were strongly inhibitory at higher concentrations. Calcium also inhibited the transduction efficiency by ∼3-fold. Two metal ions (cobalt and zinc) increased the transduction efficiency up to ∼10-fold in a dose-dependent manner. The combined use of cobalt and zinc resulted in more than an additive effect on AAV2 vector transduction efficiency (∼30-fold). The transduction efficiency of AAV serotypes 1 through 6 (AAV1-AAV6) vectors was also augmented by zinc. Similarly, the transduction of both single-stranded (ss) and self-complementary (sc) AAV3 vectors was enhanced by zinc. Zinc treatment also led to a dose-dependent increase in expression of a therapeutic protein, the human clotting factor IX (hF.IX), mediated by scAAV3 vectors in a human hepatic cell line. This simple strategy of essential metal ion-mediated enhancement may be useful to lower the dose of AAV vectors for their optimal use in human gene therapy.
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Affiliation(s)
- Himanshu K. Rambhai
- Division of Cellular and Molecular Therapy, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32611-3633, USA
- Department of Molecular Genetics & Microbiology, University of Florida College of Medicine, Gainesville, FL, USA
- Powell Gene Therapy Center, University of Florida College of Medicine, Gainesville, FL, USA
| | - Frederick J. Ashby
- Division of Cellular and Molecular Therapy, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32611-3633, USA
- Department of Molecular Genetics & Microbiology, University of Florida College of Medicine, Gainesville, FL, USA
- Powell Gene Therapy Center, University of Florida College of Medicine, Gainesville, FL, USA
| | - Keyun Qing
- Division of Cellular and Molecular Therapy, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32611-3633, USA
- Department of Molecular Genetics & Microbiology, University of Florida College of Medicine, Gainesville, FL, USA
- Powell Gene Therapy Center, University of Florida College of Medicine, Gainesville, FL, USA
| | - Arun Srivastava
- Division of Cellular and Molecular Therapy, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32611-3633, USA
- Department of Molecular Genetics & Microbiology, University of Florida College of Medicine, Gainesville, FL, USA
- Powell Gene Therapy Center, University of Florida College of Medicine, Gainesville, FL, USA
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Ku CA, Pennesi ME. The new landscape of retinal gene therapy. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2020; 184:846-859. [PMID: 32888388 DOI: 10.1002/ajmg.c.31842] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 08/07/2020] [Accepted: 08/11/2020] [Indexed: 12/15/2022]
Abstract
Novel therapeutics for inherited retinal dystrophies (IRDs) have rapidly evolved since groundbreaking clinical trials for LCA due to RPE65 mutations led to the first FDA-approved in vivo gene therapy. Since then, advancements in viral vectors have led to more efficient AAV transduction and developed other viral vectors for gene augmentation therapy of large gene targets. Furthermore, significant developments in gene editing and RNA modulation technologies have introduced novel capabilities for treatment of autosomal dominant diseases, intronic mutations, and/or large genes otherwise unable to be treated with current viral vectors. We highlight strategies currently being evaluated in gene therapy clinical trials and promising preclinical developments for IRDs.
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Affiliation(s)
- Cristy A Ku
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, USA
| | - Mark E Pennesi
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, USA
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Kumaran N, Ali RR, Tyler NA, Bainbridge JWB, Michaelides M, Rubin GS. Validation of a Vision-Guided Mobility Assessment for RPE65-Associated Retinal Dystrophy. Transl Vis Sci Technol 2020; 9:5. [PMID: 32953245 PMCID: PMC7476654 DOI: 10.1167/tvst.9.10.5] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 07/22/2020] [Indexed: 11/24/2022] Open
Abstract
Purpose To validate a vision-guided mobility assessment for individuals affected by RPE65-associated retinal dystrophy (RPE65-RD). Methods In this comparative cross-sectional study, 29 subjects, comprising 19 subjects with RPE65-RD and 10 normally-sighted subjects undertook three assessments of mobility: following a straight line, navigating a simple maze, and stepping over a sidewalk "kerb." Performance was quantified as the time taken to complete each assessment, number of errors made, walking speed, and percent preferred walking speed, for each assessment. Subjects also undertook assessments of visual acuity, contrast sensitivity, full-field static perimetry, and age-appropriate quality of life questionnaires. To identify the most relevant metric to quantify vision-guided mobility, we investigated repeatability, as well as convergent, discriminant, and criterion validity. We also measured the effect of illumination on mobility. Results Walking speed through the maze assessment best discriminated between RPE65-RD and normally-sighted subjects, with both convergent and discriminant validity. Walking speed also approached statistical significance when assessed for criterion validity (P = 0.052). Subjects with RPE65-RD had quantifiably poorer mobility at lower illumination levels. A relatively small mean difference (-0.09 m/s) was identified in comparison to a relatively large repeatability coefficient (1.10 m/s). Conclusions We describe a novel, quantifiable, repeatable, and valid assessment of mobility designed specifically for subjects with RPE65-RD. The assessment is sensitive to the visual impairment of individuals with RPE65-RD in low illumination, identifies the known phenotypic heterogeneity and will furthermore provide an important outcome measure for RPE65-RD. Translational Relevance This assessment of vision-guided mobility, validated in a dedicated cohort of subjects with RPE65-RD, is a relevant and quantifiable outcome measure for RPE65-RD.
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Affiliation(s)
- Neruban Kumaran
- UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital, London, UK.,Guy's and St. Thomas' NHS Foundation Trust, London, UK
| | - Robin R Ali
- UCL Institute of Ophthalmology, University College London, London, UK.,NIHR Moorfields Biomedical Research Centre, Moorfields Eye Hospital, London, UK
| | - Nick A Tyler
- Department of Civil, Environmental and Geomatic Engineering, University College London, London, UK
| | - James W B Bainbridge
- UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital, London, UK.,NIHR Moorfields Biomedical Research Centre, Moorfields Eye Hospital, London, UK
| | - Michel Michaelides
- UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital, London, UK.,NIHR Moorfields Biomedical Research Centre, Moorfields Eye Hospital, London, UK
| | - Gary S Rubin
- UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital, London, UK.,NIHR Moorfields Biomedical Research Centre, Moorfields Eye Hospital, London, UK
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120
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Akil O. Dual and triple AAV delivery of large therapeutic gene sequences into the inner ear. Hear Res 2020; 394:107912. [DOI: 10.1016/j.heares.2020.107912] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 02/04/2020] [Accepted: 02/07/2020] [Indexed: 12/17/2022]
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121
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Kumaran N, Georgiou M, Bainbridge JWB, Bertelsen M, Larsen M, Blanco-Kelly F, Ayuso C, Tran HV, Munier FL, Kalitzeos A, Michaelides M. Retinal Structure in RPE65-Associated Retinal Dystrophy. Invest Ophthalmol Vis Sci 2020; 61:47. [PMID: 32347917 PMCID: PMC7401957 DOI: 10.1167/iovs.61.4.47] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Purpose RPE65-associated retinal dystrophy (RPE65-RD) is an early onset, progressive, severe retinal dystrophy. We sought to characterize the natural history of retinal degeneration in affected individuals. Methods We performed cross-sectional and longitudinal quantitative and qualitative assessments of retinal architecture in RPE65-RD using spectral domain optical coherence tomography (SD-OCT) and fundus autofluorescence (FAF) imaging. Twenty-six subjects (mean age, 14.8 years, range, 5-24 years) with RPE65-RD underwent SD-OCT and FAF imaging, of whom 14 subjects were followed up over time. Foveal thickness (FT), outer nuclear layer thickness (ONLT), ellipsoid zone width (EZW), and ellipsoid zone area (EZA) were calculated where possible. These were correlated with age, best corrected visual acuity (BCVA), and central 30° retinal sensitivity (V30). Intra-observer agreement, test-retest repeatability, and interocular symmetry were also investigated. Results We identified structural interocular symmetry, the presence of autofluorescence in 46% (12/26) of subjects, and the presence of foveal hypoplasia (associated with significantly worse BCVA) in 50% of subjects. EZW and EZA were measurable in 67% (35/52) and 37% (19/52) of eyes, respectively, with both demonstrating good agreement on repeated measurement. The annual rate of progression using EZW was -300.63 µm/year, and -1.17 mm2/year in EZA. EZW was found to have a statistically significant correlation with BCVA and V30. Conclusions We identified the presence of autofluorescence in half of our subjects, with foveal hypoplasia also noted in half of our cohort. EZW, and to a lesser extent EZA, were robust measures of retinal degeneration and represent valuable metrics to determine the impact of intervention. (ClinicalTrials.gov number NCT02714816.).
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Batabyal S, Gajjeraman S, Bhattacharya S, Wright W, Mohanty S. Nano-enhanced Optical Gene Delivery to Retinal Degenerated Mice. Curr Gene Ther 2020; 19:318-329. [PMID: 31625475 DOI: 10.2174/1566523219666191017114044] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 08/19/2019] [Accepted: 09/19/2019] [Indexed: 12/14/2022]
Abstract
BACKGROUND The efficient and targeted delivery of genes and other impermeable therapeutic molecules into retinal cells is of immense importance for the therapy of various visual disorders. Traditional methods for gene delivery require viral transfection, or chemical methods that suffer from one or many drawbacks, such as low efficiency, lack of spatially targeted delivery, and can generally have deleterious effects, such as unexpected inflammatory responses and immunological reactions. METHODS We aim to develop a continuous wave near-infrared laser-based Nano-enhanced Optical Delivery (NOD) method for spatially controlled delivery of ambient-light-activatable Muti-Characteristic opsin-encoding genes into retina in-vivo and ex-vivo. In this method, the optical field enhancement by gold nanorods is utilized to transiently permeabilize cell membrane, enabling delivery of exogenous impermeable molecules to nanorod-binding cells in laser-irradiated regions. RESULTS AND DISCUSSION With viral or other non-viral (e.g. electroporation, lipofection) methods, gene is delivered everywhere, causing uncontrolled expression over the whole retina. This will cause complications in the functioning of non-degenerated areas of the retina. In the NOD method, the contrast in temperature rise in laser-irradiated nanorod-attached cells at nano-hotspots is significant enough to allow site-specific delivery of large genes. The in-vitro and in-vivo results using NOD, clearly demonstrate in-vivo gene delivery and functional cellular expression in targeted retinal regions without compromising the structural integrity of the eye or causing immune response. CONCLUSION The successful delivery and expression of MCO in the targeted retina after in-vivo NOD in the mice models of retinal degeneration opens a new vista for re-photosensitizing retina with geographic atrophies, such as in dry age-related macular degeneration.
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Affiliation(s)
- Subrata Batabyal
- Nanoscope Technologies LLC, 1312 Brown Trail, Bedford, TX, 76022, United States
| | | | | | - Weldon Wright
- Nanoscope Technologies LLC, 1312 Brown Trail, Bedford, TX, 76022, United States
| | - Samarendra Mohanty
- Nanoscope Technologies LLC, 1312 Brown Trail, Bedford, TX, 76022, United States
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Tay LS, Palmer N, Panwala R, Chew WL, Mali P. Translating CRISPR-Cas Therapeutics: Approaches and Challenges. CRISPR J 2020; 3:253-275. [PMID: 32833535 PMCID: PMC7469700 DOI: 10.1089/crispr.2020.0025] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
CRISPR-Cas clinical trials have begun, offering a first glimpse at how DNA and RNA targeting could enable therapies for many genetic and epigenetic human diseases. The speedy progress of CRISPR-Cas from discovery and adoption to clinical use is built on decades of traditional gene therapy research and belies the multiple challenges that could derail the successful translation of these new modalities. Here, we review how CRISPR-Cas therapeutics are translated from technological systems to therapeutic modalities, paying particular attention to the therapeutic cascade from cargo to delivery vector, manufacturing, administration, pipelines, safety, and therapeutic target profiles. We also explore potential solutions to some of the obstacles facing successful CRISPR-Cas translation. We hope to illuminate how CRISPR-Cas is brought from the academic bench toward use in the clinic.
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Affiliation(s)
- Lavina Sierra Tay
- Laboratory of Synthetic Biology and Genome Editing Therapeutics, Genome Institute of Singapore, Agency for Science, Technology and Research, Singapore, Singapore
| | - Nathan Palmer
- Division of Biological Sciences, University of California San Diego, La Jolla, California, USA
| | - Rebecca Panwala
- Department of Bioengineering, University of California San Diego, La Jolla, California, USA
| | - Wei Leong Chew
- Laboratory of Synthetic Biology and Genome Editing Therapeutics, Genome Institute of Singapore, Agency for Science, Technology and Research, Singapore, Singapore
| | - Prashant Mali
- Department of Bioengineering, University of California San Diego, La Jolla, California, USA
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Xu J, DeVries SH, Zhu Y. Quantification of Adeno-Associated Virus with Safe Nucleic Acid Dyes. Hum Gene Ther 2020; 31:1086-1099. [PMID: 32368927 DOI: 10.1089/hum.2020.063] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Adeno-associated virus (AAV) is the most commonly used viral vector for both biological and gene therapeutic applications. Although many methods have been developed to measure quantity attributes of AAV, they are often technically challenging and time-consuming. Here, we report a method to titer AAV with GelGreen® dye, a safe green fluorescence nucleic acid dye recently engineered by Biotium company (Fremont, CA). This method, hereinafter referred to as GelGreen method, provides a fast (∼30 min) and reliable strategy for AAV titration. To validate GelGreen method, we measured genome titer of an AAV reference material AAV8RSM and compared our titration results with those determined by Reference Material Working Group (ARMWG). We showed that GelGreen results and capsid enzyme-linked immunosorbent assay results are comparable with each other. We also showed that GelRed® dye, a red fluorescence dye from Biotium, can be used to directly "visualize" AAV genome titer on a conventional gel imager, presenting an especially direct approach to estimate viral quantity. Finally, we showed that GelGreen and GelRed dyes can also be used to quantify self-complementary AAV (scAAV) and crudely purified AAV samples. In summary, we described a technique to titer AAV by using new generation of safe DNA dyes. This technique is simple, safe, reliable, and cost efficient. It has potential to be broadly applied for quantifying and normalizing AAV viral vectors.
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Affiliation(s)
- Jian Xu
- Department of Ophthalmology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Steven H DeVries
- Department of Ophthalmology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Yongling Zhu
- Department of Ophthalmology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
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Garafalo AV, Cideciyan AV, Héon E, Sheplock R, Pearson A, WeiYang Yu C, Sumaroka A, Aguirre GD, Jacobson SG. Progress in treating inherited retinal diseases: Early subretinal gene therapy clinical trials and candidates for future initiatives. Prog Retin Eye Res 2020; 77:100827. [PMID: 31899291 PMCID: PMC8714059 DOI: 10.1016/j.preteyeres.2019.100827] [Citation(s) in RCA: 109] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Revised: 12/21/2019] [Accepted: 12/26/2019] [Indexed: 12/15/2022]
Abstract
Due to improved phenotyping and genetic characterization, the field of 'incurable' and 'blinding' inherited retinal diseases (IRDs) has moved substantially forward. Decades of ascertainment of IRD patient data from Philadelphia and Toronto centers illustrate the progress from Mendelian genetic types to molecular diagnoses. Molecular genetics have been used not only to clarify diagnoses and to direct counseling but also to enable the first clinical trials of gene-based treatment in these diseases. An overview of the recent reports of gene augmentation clinical trials by subretinal injections is used to reflect on the reasons why there has been limited success in this early venture into therapy. These first-in human experiences have taught that there is a need for advancing the techniques of delivery of the gene products - not only for refining further subretinal trials, but also for evaluating intravitreal delivery. Candidate IRDs for intravitreal gene delivery are then suggested to illustrate some of the disorders that may be amenable to improvement of remaining central vision with the least photoreceptor trauma. A more detailed understanding of the human IRDs to be considered for therapy and the calculated potential for efficacy should be among the routine prerequisites for initiating a clinical trial.
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Affiliation(s)
- Alexandra V Garafalo
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Artur V Cideciyan
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Elise Héon
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
| | - Rebecca Sheplock
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Alexander Pearson
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
| | - Caberry WeiYang Yu
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
| | - Alexander Sumaroka
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Gustavo D Aguirre
- Division of Experimental Retinal Therapies, Department of Clinical Sciences & Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Samuel G Jacobson
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.
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Shen J, Kim J, Tzeng SY, Ding K, Hafiz Z, Long D, Wang J, Green JJ, Campochiaro PA. Suprachoroidal gene transfer with nonviral nanoparticles. SCIENCE ADVANCES 2020; 6:eaba1606. [PMID: 32937452 PMCID: PMC7458446 DOI: 10.1126/sciadv.aba1606] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 04/20/2020] [Indexed: 05/16/2023]
Abstract
Subretinal injections of viral vectors provide great benefits but have limited cargo capacity; they induce innate and adaptive immune responses, which may cause damage and preclude repeated injections; and they pose administration risks. As a new biotechnology, suprachoroidal injections of biodegradable nanoparticles (NPs) containing a reporter plasmid induce reporter expression in rat photoreceptors and RPE throughout the entire eye and maintain expression for at least 8 months. Multiple injections markedly increase expression. Suprachoroidal injection of NPs containing a VEGF expression plasmid caused severe subretinal neovascularization progressing to subretinal fibrosis, similar to what occurs in untreated patients with neovascular age-related macular degeneration, providing a new model and proof of concept for level and duration of expression. Suprachoroidal injection of NPs containing a VEGF-binding protein expression plasmid significantly suppressed VEGF-induced vascular leakage and neovascularization demonstrating therapeutic potential. These data suggest that nonviral NP suprachoroidal gene transfer may provide a noninvasive, repeatable alternative to subretinal injection of viral vectors.
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Affiliation(s)
- Jikui Shen
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jayoung Kim
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Translational Tissue Engineering Center, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Stephany Y Tzeng
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Translational Tissue Engineering Center, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Kun Ding
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Zibran Hafiz
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Da Long
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jiangxia Wang
- Johns Hopkins Biostatistics Center, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Jordan J Green
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Translational Tissue Engineering Center, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD, USA
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, USA
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD, USA
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Peter A Campochiaro
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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Liu X, Feng B, Vats A, Tang H, Seibel W, Swaroop M, Tawa G, Zheng W, Byrne L, Schurdak M, Chen Y. Pharmacological clearance of misfolded rhodopsin for the treatment of RHO-associated retinitis pigmentosa. FASEB J 2020; 34:10146-10167. [PMID: 32536017 DOI: 10.1096/fj.202000282r] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 05/07/2020] [Accepted: 05/15/2020] [Indexed: 01/20/2023]
Abstract
Rhodopsin mutation and misfolding is a common cause of autosomal dominant retinitis pigmentosa (RP). Using a luciferase reporter assay, we undertook a small-molecule high-throughput screening (HTS) of 68, 979 compounds and identified nine compounds that selectively reduced the misfolded P23H rhodopsin without an effect on the wild type (WT) rhodopsin protein. Further, we found five of these compounds, including methotrexate (MTX), promoted P23H rhodopsin degradation that also cleared out other misfolded rhodopsin mutant proteins. We showed MTX increased P23H rhodopsin degradation via the lysosomal but not the proteasomal pathway. Importantly, one intravitreal injection (IVI) of 25 pmol MTX increased electroretinogram (ERG) response and rhodopsin level in the retinae of RhoP23H/+ knock-in mice at 1 month of age. Additionally, four weekly IVIs increased the photoreceptor cell number in the retinae of RhoP23H/+ mice compared to vehicle control. Our study indicates a therapeutic potential of repurposing MTX for the treatment of rhodopsin-associated RP.
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Affiliation(s)
- Xujie Liu
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, USA.,McGowan Institute of Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Bing Feng
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, USA.,McGowan Institute of Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Abhishek Vats
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, USA.,McGowan Institute of Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Hong Tang
- Drug Discovery Center, University of Cincinnati, Cincinnati, OH, USA
| | - William Seibel
- Drug Discovery Center, University of Cincinnati, Cincinnati, OH, USA.,Oncology Department, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Manju Swaroop
- National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD, USA
| | - Gregory Tawa
- National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD, USA
| | - Wei Zheng
- National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD, USA
| | - Leah Byrne
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, USA.,McGowan Institute of Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Mark Schurdak
- Drug Discovery Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Yuanyuan Chen
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, USA.,McGowan Institute of Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA
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128
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Vasconcelos HM, Lujan BJ, Pennesi ME, Yang P, Lauer AK. Intraoperative optical coherence tomographic findings in patients undergoing subretinal gene therapy surgery. Int J Retina Vitreous 2020; 6:13. [PMID: 32377379 PMCID: PMC7193395 DOI: 10.1186/s40942-020-00216-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 03/24/2020] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND To analyze intraoperative OCT (iOCT) findings during subretinal gene therapy. METHODS A single-center, retrospective, observational, case series study of twenty one eyes submitted to subretinal gene therapy. Intrasurgical high definition videos were included for analyzes. Cases with absence of iOCT video or unsuccessful bleb creation were excluded. Sharp needle tip (SNT) or blunted needle tip (BNT) and their interaction with neurosensory retina were evaluated. Presence of subretinal air bubbles, visible opened retinotomy, and medication reflux were also correlated and analyzed. RESULTS Nineteen of twenty-one eyes were included. Of the two excluded eyes, subretinal bleb creation was unsuccessful in one and technical issues prevented OCT image acquisition in the other. Immediately before subretinal injection, needle indention/penetration of the neurosensory retina with temporary indentation of the RPE/choroid was evident in 16 (84%) of the 19 eyes. Complete RPE/choroid indentation was needed with BNT use compared to SNT (p = 0.0114). An open retinotomy was identified in 14 (74%) of 19 eyes at the conclusion of bleb injection and was more commonly associated with SNT (p = 0.0108). CONCLUSIONS iOCT provides valuable real-time feedback of cross-sectional retinal anatomy during subretinal gene therapy surgeries. The type of needle tip and its use during the gene therapy procedure seems to influence in the bleb creation and presence of visible open retinotomy. Further studies of iOCT findings during gene therapy delivery procedures are likely to help refine the surgical technique.
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Affiliation(s)
- Huber M. Vasconcelos
- Casey Eye Institute, Oregon Health & Science University, 3375 SW Terwilliger Blvd, Portland, OR 97239 USA
- Department of Ophthalmology and Visual Sciences, Paulista School of Medicine, Federal University of São Paulo, São Paulo, Brazil
| | - Brandon J. Lujan
- Casey Eye Institute, Oregon Health & Science University, 3375 SW Terwilliger Blvd, Portland, OR 97239 USA
| | - Mark E. Pennesi
- Casey Eye Institute, Oregon Health & Science University, 3375 SW Terwilliger Blvd, Portland, OR 97239 USA
| | - Paul Yang
- Casey Eye Institute, Oregon Health & Science University, 3375 SW Terwilliger Blvd, Portland, OR 97239 USA
| | - Andreas K. Lauer
- Casey Eye Institute, Oregon Health & Science University, 3375 SW Terwilliger Blvd, Portland, OR 97239 USA
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129
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Holtan JP, Selmer KK, Heimdal KR, Bragadóttir R. Inherited retinal disease in Norway - a characterization of current clinical and genetic knowledge. Acta Ophthalmol 2020; 98:286-295. [PMID: 31429209 DOI: 10.1111/aos.14218] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Accepted: 07/23/2019] [Indexed: 02/06/2023]
Abstract
PURPOSE The purpose of this study was to characterize current clinical and genetic knowledge of patients with inherited retinal disease in Norway and give an estimate of the prevalence. These data are necessary to identify patients eligible for new personalized medicines, to facilitate genetic counselling for their families and to plan clinical follow-up. METHODS A patient registry including clinical and genetic data was established. Clinical data were retrieved during 2003-2018. Genetic testing was performed in the period 2007-2018. RESULTS The material included 866 patients with 41 clinical diagnoses at the cut-off date. The most prevalent diseases were as follows: retinitis pigmentosa (54%), Stargardt macular dystrophy (6.5%) and Leber congenital amaurosis (5.2%). A genetic diagnosis was identified in 32% of patients. In total, 207 disease-causing variants in 56 genes were reported. The most commonly reported disease-causing genes were ABCA4, USH2A and BEST1. The estimated adjusted minimum prevalence of inherited retinal disease in the south-east region of Norway was 1: 3,856 (2.6/10 000). CONCLUSION This population-based study demonstrated an estimated prevalence for all inherited retinal diseases in south-east Norway and described the distribution of clinical diagnoses, onset of symptoms, inheritance patterns and genetic data and thereby expands our knowledge of inherited retinal disease in Norway. The newly established registry and biobank will support patient feasibility for future clinical trials, treatment selection and counselling of families.
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Affiliation(s)
- Josephine Prener Holtan
- Department of Ophthalmology Oslo University Hospital Oslo Norway
- University of Oslo Oslo Norway
| | - Kaja Kristine Selmer
- Department of Medical Genetics Oslo University Hospital Oslo Norway
- Department of Research and Development Oslo University Hospital Oslo Norway
| | | | - Ragnheiður Bragadóttir
- Department of Ophthalmology Oslo University Hospital Oslo Norway
- University of Oslo Oslo Norway
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130
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Khan N, Cheemadan S, Saxena H, Bammidi S, Jayandharan GR. MicroRNA-based recombinant AAV vector assembly improves efficiency of suicide gene transfer in a murine model of lymphoma. Cancer Med 2020; 9:3188-3201. [PMID: 32108448 PMCID: PMC7196056 DOI: 10.1002/cam4.2935] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Revised: 02/01/2020] [Accepted: 02/04/2020] [Indexed: 12/12/2022] Open
Abstract
Recent success in clinical trials with recombinant Adeno-associated virus (AAV)-based gene therapy has redirected efforts in optimizing AAV assembly and production, to improve its potency. We reasoned that inclusion of a small RNA during vector assembly, which specifically alters the phosphorylation status of the packaging cells may be beneficial. We thus employed microRNAs (miR-431, miR-636) identified by their ability to bind AAV genome and also dysregulate Mitogen-activated protein kinase (MAPK) signaling during vector production, by a global transcriptome study in producer cells. A modified vector assembly protocol incorporating a plasmid encoding these microRNAs was developed. AAV2 vectors packaged in the presence of microRNA demonstrated an improved gene transfer potency by 3.7-fold, in vitro. Furthermore, AAV6 serotype vectors encoding an inducible caspase 9 suicide gene, packaged in the presence of miR-636, showed a significant tumor regression (~2.2-fold, P < .01) in a syngeneic murine model of T-cell lymphoma. Taken together, we have demonstrated a simple but effective microRNA-based approach to improve the assembly and potency of suicide gene therapy with AAV vectors.
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Affiliation(s)
- Nusrat Khan
- Department of Biological Sciences and BioengineeringIndian Institute of TechnologyKanpurUPIndia
| | - Sabna Cheemadan
- Centre for Stem Cell ResearchChristian Medical CollegeVelloreTNIndia
| | - Himanshi Saxena
- Department of Biological Sciences and BioengineeringIndian Institute of TechnologyKanpurUPIndia
| | - Sridhar Bammidi
- Department of Biological Sciences and BioengineeringIndian Institute of TechnologyKanpurUPIndia
| | - Giridhara R. Jayandharan
- Department of Biological Sciences and BioengineeringIndian Institute of TechnologyKanpurUPIndia
- Centre for Stem Cell ResearchChristian Medical CollegeVelloreTNIndia
- Department of HematologyChristian Medical CollegeVelloreTNIndia
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131
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Kwon HJ, Qing K, Ponnazhagan S, Wang XS, Markusic DM, Gupte S, Boye SE, Srivastava A. Adeno-Associated Virus D-Sequence-Mediated Suppression of Expression of a Human Major Histocompatibility Class II Gene: Implications in the Development of Adeno-Associated Virus Vectors for Modulating Humoral Immune Response. Hum Gene Ther 2020; 31:565-574. [PMID: 32220217 DOI: 10.1089/hum.2020.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
A 20-nt long sequence, termed the D-sequence, in the adeno-associated virus (AAV) inverted terminal repeat was observed to share a partial sequence homology with the X-box in the regulatory region of the human leukocyte antigen DRA (HLA-DRA) promoter of the human major histocompatibility complex class II (MHC-II) genes. The D-sequence was also shown to specifically interact with the regulatory factor binding to the X-box (RFX), binding of which to the X-box is a critical step in the MHC-II gene expression, suggesting that D-sequence might compete for RFX transcription factor binding, thereby suppressing expression from the MHC-II promoter. In DNA-mediated transfection experiments, using a reporter gene under the control of the HLA-DRA promoter, D-sequence oligonucleotides were found to inhibit expression of the reporter gene expression in HeLa and 293 cells by ∼93% and 96%, respectively. No inhibition was observed when nonspecific synthetic oligonucleotides were used. D-sequence oligonucleotides had no effect on expression from the cytomegalovirus immediate-early gene promoter. Interferon-γ-mediated activation of MHC-II gene expression was also inhibited by D-sequence oligonucleotides as well as after infection with either the wild-type AAV or transduction with recombinant AAV vectors. These studies suggest that the D-sequence-mediated downregulation of the MHC-II gene expression may be exploited toward the development of novel AAV vectors capable of dampening the host humoral response, which has important implication in the optimal use of these vectors in human gene therapy.
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Affiliation(s)
- Hyung-Joo Kwon
- Department of Microbiology, Hallym University College of Medicine, Chuncheon, South Korea
| | - Keyun Qing
- Division of Cellular and Molecular Therapy, Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida, USA
| | | | | | - David M Markusic
- Department of Pediatrics, Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Siddhant Gupte
- Department of Ophthalmology, University of Florida College of Medicine, Gainesville, Florida, USA
| | - Shannon E Boye
- Department of Ophthalmology, University of Florida College of Medicine, Gainesville, Florida, USA
| | - Arun Srivastava
- Division of Cellular and Molecular Therapy, Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida, USA.,Department of Pathology, The University of Alabama at Birmingham, Birmingham, Alabama, USA.,Eli Lilly & Company, Indianapolis, Indiana, USA.,Department of Pediatrics, Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana, USA.,Department of Ophthalmology, University of Florida College of Medicine, Gainesville, Florida, USA.,Department of Molecular Genetics and Microbiology, Powell Gene Therapy Center, University of Florida College of Medicine, Gainesville, Florida, USA
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132
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Mouse γ-Synuclein Promoter-Mediated Gene Expression and Editing in Mammalian Retinal Ganglion Cells. J Neurosci 2020; 40:3896-3914. [PMID: 32300046 DOI: 10.1523/jneurosci.0102-20.2020] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 03/28/2020] [Accepted: 04/02/2020] [Indexed: 12/21/2022] Open
Abstract
Optic neuropathies are a group of optic nerve (ON) diseases caused by various insults including glaucoma, inflammation, ischemia, trauma, and genetic deficits, which are characterized by retinal ganglion cell (RGC) death and ON degeneration. An increasing number of genes involved in RGC intrinsic signaling have been found to be promising neural repair targets that can potentially be modulated directly by gene therapy, if we can achieve RGC specific gene targeting. To address this challenge, we first used adeno-associated virus (AAV)-mediated gene transfer to perform a low-throughput in vivo screening in both male and female mouse eyes and identified the mouse γ-synuclein (mSncg) promoter, which specifically and potently sustained transgene expression in mouse RGCs and also works in human RGCs. We further demonstrated that gene therapy that combines AAV-mSncg promoter with clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 gene editing can knock down pro-degenerative genes in RGCs and provide effective neuroprotection in optic neuropathies.SIGNIFICANCE STATEMENT Here, we present an RGC-specific promoter, mouse γ-synuclein (mSncg) promoter, and perform extensive characterization and proof-of-concept studies of mSncg promoter-mediated gene expression and clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 gene editing in RGCs in vivo To our knowledge, this is the first report demonstrating in vivo neuroprotection of injured RGCs and optic nerve (ON) by AAV-mediated CRISPR/Cas9 inhibition of genes that are critical for neurodegeneration. It represents a powerful tool to achieve RGC-specific gene modulation, and also opens up a promising gene therapy strategy for optic neuropathies, the most common form of eye diseases that cause irreversible blindness.
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133
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Bronstein R, Capowski EE, Mehrotra S, Jansen AD, Navarro-Gomez D, Maher M, Place E, Sangermano R, Bujakowska KM, Gamm DM, Pierce EA. A combined RNA-seq and whole genome sequencing approach for identification of non-coding pathogenic variants in single families. Hum Mol Genet 2020; 29:967-979. [PMID: 32011687 PMCID: PMC7158377 DOI: 10.1093/hmg/ddaa016] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Revised: 11/23/2019] [Accepted: 01/21/2020] [Indexed: 12/13/2022] Open
Abstract
Inherited retinal degenerations (IRDs) are at the focus of current genetic therapeutic advancements. For a genetic treatment such as gene therapy to be successful, an accurate genetic diagnostic is required. Genetic diagnostics relies on the assessment of the probability that a given DNA variant is pathogenic. Non-coding variants present a unique challenge for such assessments as compared to coding variants. For one, non-coding variants are present at much higher number in the genome than coding variants. In addition, our understanding of the rules that govern the non-coding regions of the genome is less complete than our understanding of the coding regions. Methods that allow for both the identification of candidate non-coding pathogenic variants and their functional validation may help overcome these caveats allowing for a greater number of patients to benefit from advancements in genetic therapeutics. We present here an unbiased approach combining whole genome sequencing (WGS) with patient-induced pluripotent stem cell (iPSC)-derived retinal organoids (ROs) transcriptome analysis. With this approach, we identified and functionally validated a novel pathogenic non-coding variant in a small family with a previously unresolved genetic diagnosis.
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Affiliation(s)
- Revital Bronstein
- Massachusetts Eye and Ear Infirmary, Harvard Medical School, Ocular Genomics Institute, Boston, MA 02114, USA
| | - Elizabeth E Capowski
- Waisman Center Stem Cell Research Program, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Sudeep Mehrotra
- Massachusetts Eye and Ear Infirmary, Harvard Medical School, Ocular Genomics Institute, Boston, MA 02114, USA
| | - Alex D Jansen
- Waisman Center Stem Cell Research Program, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Daniel Navarro-Gomez
- Massachusetts Eye and Ear Infirmary, Harvard Medical School, Ocular Genomics Institute, Boston, MA 02114, USA
| | - Mathew Maher
- Massachusetts Eye and Ear Infirmary, Harvard Medical School, Ocular Genomics Institute, Boston, MA 02114, USA
| | - Emily Place
- Massachusetts Eye and Ear Infirmary, Harvard Medical School, Ocular Genomics Institute, Boston, MA 02114, USA
| | - Riccardo Sangermano
- Massachusetts Eye and Ear Infirmary, Harvard Medical School, Ocular Genomics Institute, Boston, MA 02114, USA
| | - Kinga M Bujakowska
- Massachusetts Eye and Ear Infirmary, Harvard Medical School, Ocular Genomics Institute, Boston, MA 02114, USA
| | - David M Gamm
- Department of Ophthalmology and Visual Sciences, Waisman Center Stem Cell Research Program, McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Eric A Pierce
- Massachusetts Eye and Ear Infirmary, Harvard Medical School, Ocular Genomics Institute, Boston, MA 02114, USA
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134
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Maurya S, Jayandharan GR. Exosome-associated SUMOylation mutant AAV demonstrates improved ocular gene transfer efficiency in vivo. Virus Res 2020; 283:197966. [PMID: 32302639 PMCID: PMC7212041 DOI: 10.1016/j.virusres.2020.197966] [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] [Received: 01/08/2020] [Revised: 02/24/2020] [Accepted: 04/08/2020] [Indexed: 01/08/2023]
Abstract
Exosome associated Adeno-associated virus (AAV) vectors have emerged as a promising tool in gene therapy. Recently, we elucidated the role of SUMOylation post-translational modification in AAV2 capsid and demonstrated that capsid modifications at SUMOylation sites, enhance vector transduction. The present study was designed to study the combinatorial effect of exosome delivery of a SUMOylation site modified AAV2, during ocular gene therapy. In the first set of experiments, we investigated the in vitro gene transfer potential of exo-some-associated SUMOylation mutant AAV2 (Exo-K105Q-EGFP) in human retinal pigmental epithelial (ARPE19) cells. Our data showed that, Exo-K105Q vectors had a significantly higher transduction potential in ARPE19 cells when compared to exosomes derived from wildtype AAV2 (Exo-AAV2-EGFP) vector packaging. Subsequently, an intravitreal administration of exosome associated mutant AAV2 vectors in C57BL6/J mice, demonstrated a significant increase reporter gene (EFGP) expression 4 weeks after gene transfer. Further immunostaining, revealed that these exosome-based vectors also had a better permeation across the retinal layers. These data highlight the translational potential of exosome associated SUMOylation mutant AAV for ocular gene therapy.
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Affiliation(s)
- Shubham Maurya
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur, India
| | - Giridhara R Jayandharan
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur, India.
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135
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Abstract
Although the sequence of the AAV inverted terminal repeat has been known for 40 years, there are still unanswered questions about functions attributable to the terminal 125 nucleotides.
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Affiliation(s)
- Kenneth I Berns
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida, USA
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136
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Ciulla TA, Hussain RM, Berrocal AM, Nagiel A. Voretigene neparvovec-rzyl for treatment of RPE65-mediated inherited retinal diseases: a model for ocular gene therapy development. Expert Opin Biol Ther 2020; 20:565-578. [DOI: 10.1080/14712598.2020.1740676] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Thomas A. Ciulla
- Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, IN, USA
- Retina Service, Midwest Eye Institute, Indianapolis, IN, USA
| | | | - Audina M. Berrocal
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Aaron Nagiel
- Department of Surgery, the Vision Center, Children’s Hospital Los Angeles, Los Angeles, CA, USA
- The Saban Research Institute, Children’s Hospital Los Angeles, Los Angeles, CA, USA
- USC Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
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137
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Liu W, Kleine-Holthaus SM, Herranz-Martin S, Aristorena M, Mole SE, Smith AJ, Ali RR, Rahim AA. Experimental gene therapies for the NCLs. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165772. [PMID: 32220628 DOI: 10.1016/j.bbadis.2020.165772] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 03/16/2020] [Accepted: 03/17/2020] [Indexed: 02/06/2023]
Abstract
The neuronal ceroid lipofuscinoses (NCLs), also known as Batten disease, are a group of rare monogenic neurodegenerative diseases predominantly affecting children. All NCLs are lethal and incurable and only one has an approved treatment available. To date, 13 NCL subtypes (CLN1-8, CLN10-14) have been identified, based on the particular disease-causing defective gene. The exact functions of NCL proteins and the pathological mechanisms underlying the diseases are still unclear. However, gene therapy has emerged as an attractive therapeutic strategy for this group of conditions. Here we provide a short review discussing updates on the current gene therapy studies for the NCLs.
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Affiliation(s)
- Wenfei Liu
- UCL School of Pharmacy, University College London, UK
| | | | - Saul Herranz-Martin
- UCL School of Pharmacy, University College London, UK; Centro de Biología Molecular Severo Ochoa (UAM-CSIC) and Departamento de Biología Molecular,Universidad Autónoma de Madrid (UAM), Madrid, Spain
| | | | - Sara E Mole
- MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK; UCL Great Ormond Street Institute of Child Health, 30 Guildford Street, London WC1N 1EH, UK
| | | | - Robin R Ali
- UCL Institute of Ophthalmology, University College London, UK; NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust, UK
| | - Ahad A Rahim
- UCL School of Pharmacy, University College London, UK.
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138
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Kleinlogel S, Vogl C, Jeschke M, Neef J, Moser T. Emerging approaches for restoration of hearing and vision. Physiol Rev 2020; 100:1467-1525. [DOI: 10.1152/physrev.00035.2019] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Impairments of vision and hearing are highly prevalent conditions limiting the quality of life and presenting a major socioeconomic burden. For long, retinal and cochlear disorders have remained intractable for causal therapies, with sensory rehabilitation limited to glasses, hearing aids, and electrical cochlear or retinal implants. Recently, the application of gene therapy and optogenetics to eye and ear has generated hope for a fundamental improvement of vision and hearing restoration. To date, one gene therapy for the restoration of vision has been approved and undergoing clinical trials will broaden its application including gene replacement, genome editing, and regenerative approaches. Moreover, optogenetics, i.e. controlling the activity of cells by light, offers a more general alternative strategy. Over little more than a decade, optogenetic approaches have been developed and applied to better understand the function of biological systems, while protein engineers have identified and designed new opsin variants with desired physiological features. Considering potential clinical applications of optogenetics, the spotlight is on the sensory systems. Multiple efforts have been undertaken to restore lost or hampered function in eye and ear. Optogenetic stimulation promises to overcome fundamental shortcomings of electrical stimulation, namely poor spatial resolution and cellular specificity, and accordingly to deliver more detailed sensory information. This review aims at providing a comprehensive reference on current gene therapeutic and optogenetic research relevant to the restoration of hearing and vision. We will introduce gene-therapeutic approaches and discuss the biotechnological and optoelectronic aspects of optogenetic hearing and vision restoration.
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Affiliation(s)
| | | | | | | | - Tobias Moser
- Institute for Auditory Neuroscience, University Medical Center Goettingen, Germany
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139
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Khan N, Maurya S, Bammidi S, Jayandharan GR. AAV6 Vexosomes Mediate Robust Suicide Gene Delivery in a Murine Model of Hepatocellular Carcinoma. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2020; 17:497-504. [PMID: 32258213 PMCID: PMC7114838 DOI: 10.1016/j.omtm.2020.03.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 03/10/2020] [Indexed: 12/13/2022]
Abstract
During recombinant Adeno-associated virus (AAV) production, a proportionately large amount of vectors is released in the culture supernatant, which is often discarded. It has been shown that these vectors often associate with vesiculated structures, such as exosomes. Exosome-associated AAV (vexosomes) represent an additional gene-delivery platform. The efficiency of such vexosomes in suicide gene therapy is unexplored. In the present study, we have generated AAV serotype 6 vexosomes containing an inducible caspase 9 (iCasp9) suicide gene by a differential ultracentrifugation-based protocol. We further tested the cytotoxic potential of these vexosomes in a human hepatocellular carcinoma (HCC) model in vitro and in vivo. The AAV6-iCasp9 containing vexosomes, when primed with a pro-drug (AP20187), demonstrated a significant loss in cell viability (57% ± 8% versus 100% ± 4.8%, p < 0.001) in comparison to mock-treated Huh7 cells. An intratumoral administration of AAV6-iCasp9 vexosomes and AP20187 in a murine xenograft model revealed a 2.3-fold increase in tumor regression in comparison to untreated animals. These findings were further corroborated by histological analysis and apoptosis assays. In conclusion, our data demonstrate the therapeutic potential of AAV6 vexosomes in a xenotransplantation model of HCC. Furthermore, the simplicity in production and isolation of vexosomes should further facilitate its application in other malignancies.
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Affiliation(s)
- Nusrat Khan
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, Uttar Pradesh, India
| | - Shubham Maurya
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, Uttar Pradesh, India
| | - Sridhar Bammidi
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, Uttar Pradesh, India
| | - Giridhara R Jayandharan
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, Uttar Pradesh, India
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140
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Yiu G, Chung SH, Mollhoff IN, Nguyen UT, Thomasy SM, Yoo J, Taraborelli D, Noronha G. Suprachoroidal and Subretinal Injections of AAV Using Transscleral Microneedles for Retinal Gene Delivery in Nonhuman Primates. Mol Ther Methods Clin Dev 2020; 16:179-191. [PMID: 32055646 PMCID: PMC7005511 DOI: 10.1016/j.omtm.2020.01.002] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 01/06/2020] [Indexed: 02/01/2023]
Abstract
Retinal gene therapy using adeno-associated viruses (AAVs) is constrained by the mode of viral vector delivery. Intravitreal AAV injections are impeded by the internal limiting membrane barrier, while subretinal injections require invasive surgery and produce a limited region of therapeutic effect. In this study, we introduce a novel mode of ocular gene delivery in rhesus macaques using transscleral microneedles to inject AAV8 into the subretinal or suprachoroidal space, a potential space between the choroid and scleral wall of the eye. Using in vivo imaging, we found that suprachoroidal AAV8 produces diffuse, peripheral expression in retinal pigment epithelial (RPE) cells, but it elicited local infiltration of inflammatory cells. Transscleral subretinal injection of AAV8 using microneedles leads to focal gene expression with transduction of RPE and photoreceptors, and minimal intraocular inflammation. In comparison, intravitreal AAV8 shows minimal transduction of retinal cells, but elicits greater systemic humoral immune responses. Our study introduces a novel mode of transscleral viral delivery that can be performed without vitreoretinal surgery, with focal or diffuse transgene expression patterns suitable for different applications. The decoupling of local and systemic immune responses reveals important insights into the immunological consequences of AAV delivery to different ocular compartments surrounding the blood-retinal barrier.
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Affiliation(s)
- Glenn Yiu
- Department of Ophthalmology & Vision Science, University of California, Davis, 4860 Y Street, Suite 2400, Sacramento, CA 95817, USA
| | - Sook Hyun Chung
- Department of Ophthalmology & Vision Science, University of California, Davis, 4860 Y Street, Suite 2400, Sacramento, CA 95817, USA
| | - Iris N. Mollhoff
- Department of Ophthalmology & Vision Science, University of California, Davis, 4860 Y Street, Suite 2400, Sacramento, CA 95817, USA
| | - Uyen Tu Nguyen
- Department of Ophthalmology & Vision Science, University of California, Davis, 4860 Y Street, Suite 2400, Sacramento, CA 95817, USA
| | - Sara M. Thomasy
- Department of Ophthalmology & Vision Science, University of California, Davis, 4860 Y Street, Suite 2400, Sacramento, CA 95817, USA
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, 1 Garrod Drive, Davis, CA 95616, USA
| | - Jesse Yoo
- Clearside Biomedical, 900 North Point Parkway, Suite 200, Alpharetta, GA 30005, USA
| | - Donna Taraborelli
- Clearside Biomedical, 900 North Point Parkway, Suite 200, Alpharetta, GA 30005, USA
| | - Glenn Noronha
- Clearside Biomedical, 900 North Point Parkway, Suite 200, Alpharetta, GA 30005, USA
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141
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Verdera HC, Kuranda K, Mingozzi F. AAV Vector Immunogenicity in Humans: A Long Journey to Successful Gene Transfer. Mol Ther 2020; 28:723-746. [PMID: 31972133 PMCID: PMC7054726 DOI: 10.1016/j.ymthe.2019.12.010] [Citation(s) in RCA: 344] [Impact Index Per Article: 86.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 12/27/2019] [Indexed: 12/15/2022] Open
Abstract
Gene therapy with adeno-associated virus (AAV) vectors has demonstrated safety and long-term efficacy in a number of trials across target organs, including eye, liver, skeletal muscle, and the central nervous system. Since the initial evidence that AAV vectors can elicit capsid T cell responses in humans, which can affect the duration of transgene expression, much progress has been made in understanding and modulating AAV vector immunogenicity. It is now well established that exposure to wild-type AAV results in priming of the immune system against the virus, with development of both humoral and T cell immunity. Aside from the neutralizing effect of antibodies, the impact of pre-existing immunity to AAV on gene transfer is still poorly understood. Herein, we review data emerging from clinical trials across a broad range of gene therapy applications. Common features of immune responses to AAV can be found, suggesting, for example, that vector immunogenicity is dose-dependent, and that innate immunity plays an important role in the outcome of gene transfer. A range of host-specific factors are also likely to be important, and a comprehensive understanding of the mechanisms driving AAV vector immunogenicity in humans will be key to unlocking the full potential of in vivo gene therapy.
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Affiliation(s)
- Helena Costa Verdera
- Genethon and INSERM U951, 91000 Evry, France; Sorbonne Université and INSERM U974, 75013 Paris, France
| | | | - Federico Mingozzi
- Genethon and INSERM U951, 91000 Evry, France; Spark Therapeutics, Philadelphia, PA 19104, USA.
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142
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Wang X, Yu C, Tzekov RT, Zhu Y, Li W. The effect of human gene therapy for RPE65-associated Leber's congenital amaurosis on visual function: a systematic review and meta-analysis. Orphanet J Rare Dis 2020; 15:49. [PMID: 32059734 PMCID: PMC7023818 DOI: 10.1186/s13023-020-1304-1] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2019] [Accepted: 01/13/2020] [Indexed: 11/17/2022] Open
Abstract
Background RPE65-associated LCA (RPE65-LCA) is an inherited retinal degeneration caused by the mutations of RPE65 gene and gene therapy has been developed to be a promising treatment. This study aims to evaluate the association between changes in visual function and application of gene therapy in patients with RPE65-LCA. Methods Several databases (PubMed, Cochrane Library, and Web of Science) were searched for results of studies describing efficacy of gene therapy in patients with RPE65-LCA. Six studies, which included one randomized and five prospective non-randomized clinical trials, 164 eyes met our search criteria and were assessed. Results The BCVA significantly improved in treated eyes at 1 yr post treatment by − 0.10 logMAR (95% CI, − 0.17 - -0.04; p = 0·002), while there was no significant difference at 2–3 years post treatment (WMD: 0.01; 95% CI, − 0.00 - 0.02; p = 0·15). FST sensitivity to blue flashes also improved by 1.60 log (95% CI, 0.66–2.55; p = 0.0009), but no significant difference to red flashes (WMD: 0.86; 95% CI, − 0·29–2.01; p = 0.14) at 1 yr. There was no significant difference in central retinal thickness at 1 yr, but central retina in treated eyes appeared thinner at 2–3 years post treatment by 19.21 μm (95% CI, − 34.22 - -4.20; p = 0.01). Conclusions Human gene therapy is a pioneering treatment option for RPE65-LCA. Although its efficacy appears to be limited to less than 2 yrs after treatment, it carries the potential for further improvement and prolongation of efficacy.
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Affiliation(s)
- Xue Wang
- Aier School of Ophthalmology, Central South University, Changsha, China
| | - Chaofeng Yu
- Shanghai Aier Eye Hospital, 1286 Hongqiao Road, Shanghai, China
| | - Radouil T Tzekov
- Department of Ophthalmology, University of South Florida, Tampa, Florida, USA
| | - Yihua Zhu
- First Affiliated Hospital of Fujian Medical University, Fuzhou, China.
| | - Wensheng Li
- Aier School of Ophthalmology, Central South University, Changsha, China. .,Shanghai Aier Eye Hospital, 1286 Hongqiao Road, Shanghai, China.
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143
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Al-Owaid AA, Alarfaj MA, Alarfaj FA, Awad A. Intraocular Lens Dislocation into the Anterior Chamber because of Repeated Eye-Poking in a Patient with Leber's Congenital Amaurosis. Case Rep Ophthalmol 2020; 11:48-53. [PMID: 32095132 PMCID: PMC7011747 DOI: 10.1159/000505596] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 12/23/2019] [Indexed: 11/19/2022] Open
Abstract
The dislocation of a posterior chamber intraocular lens (PC IOL) because of constant eye rubbing is unusual and has never been reported in a child with Leber's congenital amaurosis (LCA). A 4-year-old full-term girl with an ocular history of LCA presented to the emergency room with a single-piece PC IOL dislocated into the anterior chamber (AC) of the left eye. There was no history of trauma or any other surgical intervention. A specific behavior known as Franceschetti's oculo-digital sign is a characteristic feature of LCA; this sign consists of repeated pressing, poking, and rubbing of the eyes with knuckles and fingers to stimulate the photoreceptors. This behavior caused the dislocation of the PC IOL into the AC. The dislocated IOL was explanted, and the patient was provided with aphakic glasses.
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Affiliation(s)
- Abdullah A Al-Owaid
- King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia.,Department of Ophthalmology, College of Medicine, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Motazz A Alarfaj
- King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia.,Department of Ophthalmology, College of Medicine, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Faris A Alarfaj
- King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia.,Department of Ophthalmology, College of Medicine, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Abdulaziz Awad
- King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia
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144
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Gene Therapy with Single-Subunit Yeast NADH-Ubiquinone Oxidoreductase (NDI1) Improves the Visual Function in Experimental Autoimmune Encephalomyelitis (EAE) Mice Model of Multiple Sclerosis (MS). Mol Neurobiol 2020; 57:1952-1965. [PMID: 31900864 DOI: 10.1007/s12035-019-01857-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 12/12/2019] [Indexed: 12/14/2022]
Abstract
Mitochondrial dysfunction mediated loss of respiration, oxidative stress, and loss of cellular homeostasis contributes to the neuronal and axonal degenerations permanent loss of function in experimental autoimmune encephalomyelitis model (EAE) of multiple sclerosis (MS). To address the mitochondrial dysfunction mediated visual loss in EAE mice, self-complementary adeno-associated virus (scAAV) containing the NADH-dehydrogenase type-2 (NDI1) complex I gene was intravitreally injected into the mice after the onset of visual defects. Visual function assessed by pattern electroretinogram (PERGs) showed progressive loss of function in EAE mice were improved significantly in NDI1 gene therapy-treated mice. Serial optical coherence tomography (OCT) revealed that progressive thinning of inner retinal layers in EAE mice was prevented upon NDI1 expression. The 45% optic nerve axonal and 33% retinal ganglion cell (RGC) loss contributed to the permanent loss of visual function in EAE mice were ameliorated by NDI1-mediated prevention of mitochondrial cristae dissolution and improved mitochondrial homeostasis. In conclusion, targeting the dysfunctional complex I using NDI1 gene can be an approach to address axonal and neuronal loss responsible for permanent disability in MS that is unaltered by current disease modifying drugs.
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145
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Zhang Y, Wang S, Xu M, Pang J, Yuan Z, Zhao C. AAV-mediated human CNGB3 restores cone function in an all-cone mouse model of CNGB3 achromatopsia. J Biomed Res 2020; 34:114-121. [PMID: 32305965 DOI: 10.7555/jbr.33.20190056] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Complete congenital achromatopsia is a devastating hereditary visual disorder. Mutations in the CNGB3 gene account for more than 50% of all known cases of achromatopsia. This work investigated the efficiency of subretinal (SR) delivered AAV8 (Y447, 733F) vector containing a human PR2.1 promoter and a human CNGB3 cDNA in Cngb3 -/-/ Nrl -/- mice. The Cngb3 -/-/ Nrl -/- mouse was a cone-dominant model with Cngb3 channel deficiency, which partially mimicked the all-cone foveal structure of human achromatopsia with CNGB3 mutations. Following SR delivery of the vector, AAV-mediated CNGB3 expression restored cone function which was assessed by the restoration of the cone-mediated electroretinogram (ERG) and immunohistochemistry. This therapeutic rescue resulted in long-term improvement of retinal function with the restoration of cone ERG amplitude. This study demonstrated an AAV-mediated gene therapy in a cone-dominant mouse model using a human gene construct and provided the potential to be utilized in clinical trials.
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Affiliation(s)
- Yuxin Zhang
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Shanshan Wang
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Miao Xu
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Jijing Pang
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China;Department of Ophthalmology, University of Florida, Gainesville, FL 32610, USA
| | - Zhilan Yuan
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Chen Zhao
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China
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146
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Gurevich VV, Gurevich EV. Targeting arrestin interactions with its partners for therapeutic purposes. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2019; 121:169-197. [PMID: 32312421 DOI: 10.1016/bs.apcsb.2019.11.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Most vertebrates express four arrestin subtypes: two visual ones in photoreceptor cells and two non-visuals expressed ubiquitously. The latter two interact with hundreds of G protein-coupled receptors, certain receptors of other types, and numerous non-receptor partners. Arrestins have no enzymatic activity and work by interacting with other proteins, often assembling multi-protein signaling complexes. Arrestin binding to every partner affects cell signaling, including pathways regulating cell survival, proliferation, and death. Thus, targeting individual arrestin interactions has therapeutic potential. This requires precise identification of protein-protein interaction sites of both participants and the choice of the side of each interaction which would be most advantageous to target. The interfaces involved in each interaction can be disrupted by small molecule therapeutics, as well as by carefully selected peptides of the other partner that do not participate in the interactions that should not be targeted.
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Affiliation(s)
- Vsevolod V Gurevich
- Department of Pharmacology, Vanderbilt University, Nashville, TN, United States
| | - Eugenia V Gurevich
- Department of Pharmacology, Vanderbilt University, Nashville, TN, United States
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147
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Muthukumar T, Song JE, Khang G. Biological Role of Gellan Gum in Improving Scaffold Drug Delivery, Cell Adhesion Properties for Tissue Engineering Applications. Molecules 2019; 24:E4514. [PMID: 31835526 PMCID: PMC6943741 DOI: 10.3390/molecules24244514] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 12/03/2019] [Accepted: 12/06/2019] [Indexed: 12/12/2022] Open
Abstract
Over the past few decades, gellan gum (GG) has attracted substantial research interest in several fields including biomedical and clinical applications. The GG has highly versatile properties like easy bio-fabrication, tunable mechanical, cell adhesion, biocompatibility, biodegradability, drug delivery, and is easy to functionalize. These properties have put forth GG as a promising material in tissue engineering and regenerative medicine fields. Nevertheless, GG alone has poor mechanical strength, stability, and a high gelling temperature in physiological conditions. However, GG physiochemical properties can be enhanced by blending them with other polymers like chitosan, agar, sodium alginate, starch, cellulose, pullulan, polyvinyl chloride, xanthan gum, and other nanomaterials, like gold, silver, or composites. In this review article, we discuss the comprehensive overview and different strategies for the preparation of GG based biomaterial, hydrogels, and scaffolds for drug delivery, wound healing, antimicrobial activity, and cell adhesion. In addition, we have given special attention to tissue engineering applications of GG, which can be combined with another natural, synthetic polymers and nanoparticles, and other composites materials. Overall, this review article clearly presents a summary of the recent advances in research studies on GG for different biomedical applications.
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Affiliation(s)
| | | | - Gilson Khang
- Department of BIN Convergence Technology, Department of Polymer Nano Science & Technology and Polymer BIN Research Center, Chonbuk National University, Deokjin-gu, Jeonju 561-756, Korea; (T.M.); (J.E.S.)
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148
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TPP Combined with DGUC as an Economic and Universal Process for Large-Scale Purification of AAV Vectors. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2019; 17:34-48. [PMID: 31890739 PMCID: PMC6926265 DOI: 10.1016/j.omtm.2019.11.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 11/09/2019] [Indexed: 12/12/2022]
Abstract
Adeno-associated virus (AAV) vectors have been commonly purified through density gradient ultracentrifugation (DGUC) or column chromatography methods. Although the DGUC method can efficiently separate the empty from the full virus particles, its application in large-scale AAV purification is hindered due to its limitation in volume of each centrifuge tube. Alternatively, column chromatography is serotype-dependent, expensive, and complicated, which co-purifies both empty and full virus particles. In this study, we describe an economical and universal process using three-phase partitioning (TPP) combined with DGUC to purify large quantities of AAV vectors. First, TPP is used to remove up to 90% of the cellular impurities in the cell lysate and at the same time condense the AAV vectors into ∼10% of their original lysate volume. Second, two rounds of DGUC are employed to separate the empty from the full virus particles and at the same time remove the remaining cellular impurities. This combined process increases the capacity of ultracentrifugation by a factor of 5- to 10-fold depending on the yields of AAV serotypes. A variety of AAV serotypes such as AAV2, AAV5, AAV6, AAV9, and AAVDJ have been successfully purified with this process. Both in vitro and in vivo studies demonstrate that TPP has no detrimental impact on AAV infectivity. In a proof of concept, we performed several purification runs ranging from 3 to 25 L of Sf9 culture volume. We were able to purify more than 3e+15 viral genomes (vg) of AAV vectors from 3 L of cell culture volume with just two SW28 centrifuge tubes in a Beckman Coulter ultracentrifuge. Our data indicate that this TPP-DGUC process is economic, universal, and can be used to purify a large quantity of AAV vectors for clinical applications with just a few ultracentrifuges.
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149
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Patrício MI, Cox CI, Blue C, Barnard AR, Martinez-Fernandez de la Camara C, MacLaren RE. Inclusion of PF68 Surfactant Improves Stability of rAAV Titer when Passed through a Surgical Device Used in Retinal Gene Therapy. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2019; 17:99-106. [PMID: 31890744 PMCID: PMC6931089 DOI: 10.1016/j.omtm.2019.11.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 11/04/2019] [Indexed: 12/31/2022]
Abstract
Recent advances in recombinant adeno-associated virus (rAAV) gene therapy for choroideremia show gene replacement to be a promising approach. It is, however, well known that contact of vector solution with plastic materials in the surgical device may result in non-specific adsorption with resulting loss of physical titer and/or level of protein expression and activity. Here we assessed the biocompatibility and stability of rAAV2-REP1 (Rab Escort Protein-1) before and following passage through the injection device over a period of time to mimic the clinical scenario. Three identical devices were screened using two concentrations of vector: high (1E+12 DNase-resistant particles [DRP]/mL) and low (1E+11 DRP/mL), to mimic high- and low-dose administrations of vector product. The low dose was prepared using either formulation buffer that contained 0.001% of a non-ionic surfactant (PF68) or balanced salt solution (BSS). We observed significant losses in the genomic titer of samples diluted with BSS for all time points. The addition of 0.001% PF68 did not, however, affect rAAV physical titer, or REP1 protein expression and biological activity. Hence we observed that neither the genomic titer nor the biological activity of a rAAV2-REP1-containing solution was affected following passage through the surgical device when PF68 was present as a surfactant and this was maintained over a period up to 10 h.
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Affiliation(s)
- Maria I Patrício
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK.,National Institute for Health Research (NIHR) Oxford Biomedical Research Centre (BRC), Oxford, UK.,Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | | | - Clare Blue
- Nightstar Therapeutics, 10 Midford Place, London, UK
| | - Alun R Barnard
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK.,National Institute for Health Research (NIHR) Oxford Biomedical Research Centre (BRC), Oxford, UK.,Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Cristina Martinez-Fernandez de la Camara
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK.,National Institute for Health Research (NIHR) Oxford Biomedical Research Centre (BRC), Oxford, UK.,Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Robert E MacLaren
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK.,National Institute for Health Research (NIHR) Oxford Biomedical Research Centre (BRC), Oxford, UK.,Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
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150
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Gene Therapy in Retinal Dystrophies. Int J Mol Sci 2019; 20:ijms20225722. [PMID: 31739639 PMCID: PMC6888000 DOI: 10.3390/ijms20225722] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 11/13/2019] [Accepted: 11/13/2019] [Indexed: 12/12/2022] Open
Abstract
Inherited retinal dystrophies (IRDs) are a group of clinically and genetically heterogeneous degenerative disorders. To date, mutations have been associated with IRDs in over 270 disease genes, but molecular diagnosis still remains elusive in about a third of cases. The methodologic developments in genome sequencing techniques that we have witnessed in this last decade have represented a turning point not only in diagnosis and prognosis but, above all, in the identification of new therapeutic perspectives. The discovery of new disease genes and pathogenetic mechanisms underlying IRDs has laid the groundwork for gene therapy approaches. Several clinical trials are ongoing, and the recent approval of Luxturna, the first gene therapy product for Leber congenital amaurosis, marks the beginning of a new era. Due to its anatomical and functional characteristics, the retina is the organ of choice for gene therapy, although there are quite a few difficulties in the translational approaches from preclinical models to humans. In the first part of this review, an overview of the current knowledge on methodological issues and future perspectives of gene therapy applied to IRDs is discussed; in the second part, the state of the art of clinical trials on the gene therapy approach in IRDs is illustrated.
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