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Berkowitz ST, Finn AP. Gene therapy for age-related macular degeneration: potential, feasibility, and pitfalls. Curr Opin Ophthalmol 2024; 35:170-177. [PMID: 38441066 DOI: 10.1097/icu.0000000000001043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2024]
Abstract
PURPOSE OF REVIEW The landscape for age-related macular degeneration (AMD) is rapidly changing with addition of biosimilars and now United States Food and Drug Administration (FDA) approved nonneovascular AMD (nnAMD) treatment options. These developments have inspired a burgeoning pipeline of gene therapy approaches focused on similar antivascular endothelial growth factors (VEGF) and complement related pathways. Historic and more recent setbacks in the gene therapy pipeline, including intraocular inflammatory reactions, have raised important concerns for adverse events related to AMD therapeutics both for gene and nongene approaches. The specific clinical profile of these therapeutics approaching later stage clinical trials are complex and under active investigation; however, these options hold promise to disrupt the current landscape and change management paradigms for one of the leading causes of vision loss worldwide. RECENT FINDINGS This review covers current gene therapy approaches for neovascular AMD (nAMD) and nnAMD. Intravitreal, suprachoroidal, and subretinal delivery routes are discussed with attention to technical procedure, capabilities for transgene delivery to target tissue, immunogenicity, and collateral effects. Suprachoroidal delivery is an emerging approach which may bridge some of the practical drawbacks for intravitreal and subretinal methods, though with less elaborated immunologic profile. In parallel to delivery modification, viral vectors have been cultivated to target specific cells, with promising enhancements in adeno-associated viral (AAV) vectors and persistent interest in alternate viral and nonviral delivery vectors. Ongoing questions such as steroid or immunosuppressive regimen and economic considerations from a payer and societal perspective are discussed. SUMMARY The present review discusses emerging gene therapy options which could foster new, more durable nAMD and nnAMD therapeutics. These options will need refinement with regards to route, vector, and dosage, and specialists must decipher the specific clinical risk benefit profile for individual patients. Ongoing concerns for immunogenicity or dosage related adverse events could stifle progress, while further vector development and refined delivery techniques have the potential to change the safety and efficacy of currently options in the pipeline.
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Affiliation(s)
- Sean T Berkowitz
- Vanderbilt University Medical Center, Department of Ophthalmology, Nashville, Tennessee, USA
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2
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Choules MP, Bonate PL, Heo N, Weddell J. Prospective approaches to gene therapy computational modeling - spotlight on viral gene therapy. J Pharmacokinet Pharmacodyn 2023:10.1007/s10928-023-09889-1. [PMID: 37848637 DOI: 10.1007/s10928-023-09889-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 09/25/2023] [Indexed: 10/19/2023]
Abstract
Clinical studies have found there still exists a lack of gene therapy dose-toxicity and dose-efficacy data that causes gene therapy dose selection to remain elusive. Model informed drug development (MIDD) has become a standard tool implemented throughout the discovery, development, and approval of pharmaceutical therapies, and has the potential to inform dose-toxicity and dose-efficacy relationships to support gene therapy dose selection. Despite this potential, MIDD approaches for gene therapy remain immature and require standardization to be useful for gene therapy clinical programs. With the goal to advance MIDD approaches for gene therapy, in this review we first provide an overview of gene therapy types and how they differ from a bioanalytical, formulation, route of administration, and regulatory standpoint. With this biological and regulatory background, we propose how MIDD can be advanced for AAV-based gene therapies by utilizing physiological based pharmacokinetic modeling and quantitative systems pharmacology to holistically inform AAV and target protein dynamics following dosing. We discuss how this proposed model, allowing for in-depth exploration of AAV pharmacology, could be the key the field needs to treat these unmet disease populations.
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Affiliation(s)
- Mary P Choules
- Early Development, New Technologies Group, Astellas, Northbrook, IL, USA
| | - Peter L Bonate
- Early Development, New Technologies Group, Astellas, Northbrook, IL, USA.
| | - Nakyo Heo
- Early Development, New Technologies Group, Astellas, Northbrook, IL, USA
| | - Jared Weddell
- Early Development, New Technologies Group, Astellas, Northbrook, IL, USA
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3
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Gyenes A, István L, Benyó F, Papp A, Resch M, Sándor N, Józsi M, Nagy ZZ, Kovács I, Kiss S. Intraocular neutralizing antibodies against aflibercept in patients with age related macular degeneration. BMC Ophthalmol 2023; 23:14. [PMID: 36627583 PMCID: PMC9830890 DOI: 10.1186/s12886-022-02761-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 12/28/2022] [Indexed: 01/11/2023] Open
Abstract
PURPOSE To detect immunoglobulins in aqueous humour of AMD patients after repeated administration of intravitreal aflibercept. PATIENTS AND METHODS Twenty-one patients (age: 77.85 ± 9.21 years) previously treated with intravitreal aflibercept due to wet type age-related macular degeneration (AMD group) and 18 age-matched control subjects (age: 69.75 ± 12.67 years) were included in this study. Patients in the AMD group received a mean of 5 intravitreal injections (min: 1 max: 17) prior to the cataract surgery. Samples of aqueous humour (50 μl) were obtained by anterior chamber paracentesis as the first step of routine cataract surgery. The IgG content of the samples was analysed by an in-house developed ELISA system. RESULTS A significant increase in nonspecific IgG levels in the AMD group was detected compared to the control group (13.37 ± 6.65 vs. 9.44 ± 6.55 μg/ml; p = 0.03). In 11 patients, intraocular anti-aflibercept immunoglobulins could be detected (0.05 ± 0.01 μg/ml) which was significantly higher than the limit of detection for anti-aflibercept (0.04 μg/ml; p = 0.001). No correlation was found between the number of injections or the type of CNV and the aqueous level of anti-aflibercept (r = 0.02; p = 0.95). CONCLUSION According to our results, penetration of non-specific systemic antibodies through the impaired blood-retinal barrier is higher in patients with neovascular AMD than in subjects with an intact structural barrier. Evaluation of neutralizing antibodies to anti-VEGF agents in the aqueous humour can lead us to understanding tachyphylaxis and changes in intraocular immune mechanisms due to AMD.
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Affiliation(s)
- Andrea Gyenes
- grid.11804.3c0000 0001 0942 9821Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Lilla István
- grid.11804.3c0000 0001 0942 9821Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Fruzsina Benyó
- grid.11804.3c0000 0001 0942 9821Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - András Papp
- grid.11804.3c0000 0001 0942 9821Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Miklós Resch
- grid.11804.3c0000 0001 0942 9821Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Noémi Sándor
- grid.5591.80000 0001 2294 6276Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary ,grid.5018.c0000 0001 2149 4407MTA-ELTE Complement Research Group, Eötvös Loránd Research Network (ELKH), Budapest, Hungary
| | - Mihály Józsi
- grid.5591.80000 0001 2294 6276Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary ,grid.5018.c0000 0001 2149 4407MTA-ELTE Complement Research Group, Eötvös Loránd Research Network (ELKH), Budapest, Hungary
| | - Zoltán Z. Nagy
- grid.11804.3c0000 0001 0942 9821Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Illés Kovács
- grid.11804.3c0000 0001 0942 9821Department of Ophthalmology, Semmelweis University, Budapest, Hungary ,grid.5386.8000000041936877XDepartment of Ophthalmology, Weill Cornell Medical College, New York, USA ,grid.11804.3c0000 0001 0942 9821Department of Clinical Ophthalmology, Faculty of Health Sciences, Semmelweis University, Budapest, Hungary
| | - Szilárd Kiss
- grid.5386.8000000041936877XDepartment of Ophthalmology, Weill Cornell Medical College, New York, USA
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4
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In situ transduction of cells in human corneal limbus using adeno-associated viruses: an ex vivo study. Sci Rep 2022; 12:22481. [PMID: 36577775 PMCID: PMC9797548 DOI: 10.1038/s41598-022-26926-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Accepted: 12/21/2022] [Indexed: 12/30/2022] Open
Abstract
This study aimed to evaluate the efficacy of in situ adeno-associated virus (AAV)-mediated gene delivery into the human corneal limbal region via targeted sub-limbal injection technique. Human cadaveric corneal tissues were fixed on an artificial anterior chamber. Feasibility of sub-limbal injection technique was tested using trypan blue and black India ink. An enhanced green fluorescent protein (eGFP) encoding AAV DJ was injected into sub-limbal region. After AAV injection, corneal tissues were incubated in air-lift culture and prepared for immunohistochemical analysis. Cell survivial and expression of eGFP, stem cell markers (p63α and cytokeratin 19 (KRT19)), and differentiation marker cytokeratin 3 (KRT3) were evaluated using confocal microscopy. Both trypan blue and black India ink stained and were retained sub-limbally establishing specificity of the injection technique. Immunohistochemical analysis of corneas injected with AAV DJ-eGFP indicated that AAV-transduced cells in the limbal region co-express eGFP, p63α, and KRT19 and that these transduced cells were capable of differentiating to KRT3 postitive corneal epithelial cells. Our sub-limbal injection technique can target cells in the human limbus in a reproducible and efficient manner. Thus, we demonstrate that in situ injection of corneal limbus may provide a feasible mode of genetic therapy for corneal disorders with an epithelial etiology.
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Karamali F, Behtaj S, Babaei-Abraki S, Hadady H, Atefi A, Savoj S, Soroushzadeh S, Najafian S, Nasr Esfahani MH, Klassen H. Potential therapeutic strategies for photoreceptor degeneration: the path to restore vision. J Transl Med 2022; 20:572. [PMID: 36476500 PMCID: PMC9727916 DOI: 10.1186/s12967-022-03738-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 10/29/2022] [Indexed: 12/12/2022] Open
Abstract
Photoreceptors (PRs), as the most abundant and light-sensing cells of the neuroretina, are responsible for converting light into electrical signals that can be interpreted by the brain. PR degeneration, including morphological and functional impairment of these cells, causes significant diminution of the retina's ability to detect light, with consequent loss of vision. Recent findings in ocular regenerative medicine have opened promising avenues to apply neuroprotective therapy, gene therapy, cell replacement therapy, and visual prostheses to the challenge of restoring vision. However, successful visual restoration in the clinical setting requires application of these therapeutic approaches at the appropriate stage of the retinal degeneration. In this review, firstly, we discuss the mechanisms of PR degeneration by focusing on the molecular mechanisms underlying cell death. Subsequently, innovations, recent developments, and promising treatments based on the stage of disorder progression are further explored. Then, the challenges to be addressed before implementation of these therapies in clinical practice are considered. Finally, potential solutions to overcome the current limitations of this growing research area are suggested. Overall, the majority of current treatment modalities are still at an early stage of development and require extensive additional studies, both pre-clinical and clinical, before full restoration of visual function in PR degeneration diseases can be realized.
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Affiliation(s)
- Fereshteh Karamali
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Sanaz Behtaj
- grid.1022.10000 0004 0437 5432Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Queensland, Australia ,grid.1022.10000 0004 0437 5432Menzies Health Institute Queensland, Griffith University, Southport, QLD 4222 Australia
| | - Shahnaz Babaei-Abraki
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Hanieh Hadady
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Atefeh Atefi
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Soraya Savoj
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Sareh Soroushzadeh
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Samaneh Najafian
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Mohammad Hossein Nasr Esfahani
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Henry Klassen
- grid.266093.80000 0001 0668 7243Gavin Herbert Eye Institute, Irvine, CA USA
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Ross M, Obolensky A, Averbukh E, Desrosiers M, Ezra-Elia R, Honig H, Yamin E, Rosov A, Dvir H, Gootwine E, Banin E, Dalkara D, Ofri R. Outer retinal transduction by AAV2-7m8 following intravitreal injection in a sheep model of CNGA3 achromatopsia. Gene Ther 2022; 29:624-635. [PMID: 34853444 DOI: 10.1038/s41434-021-00306-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Revised: 10/26/2021] [Accepted: 11/15/2021] [Indexed: 01/09/2023]
Abstract
Sheep carrying a mutated CNGA3 gene exhibit diminished cone function and provide a naturally occurring large animal model of achromatopsia. Subretinal injection of a vector carrying the CNGA3 transgene resulted in long-term recovery of cone function and photopic vision in these sheep. Research is underway to develop efficacious vectors that would enable safer transgene delivery, while avoiding potential drawbacks of subretinal injections. The current study evaluated two modified vectors, adeno-associated virus 2-7m8 (AAV2-7m8) and AAV9-7m8. Intravitreal injection of AAV2-7m8 carrying enhanced green fluorescent protein under a cone-specific promoter resulted in moderate photoreceptor transduction in wild-type sheep, whereas peripheral subretinal delivery of AAV9-7m8 resulted in the radial spread of the vector beyond the point of deposition. Intravitreal injection of AAV2-7m8 carrying human CNGA3 in mutant sheep resulted in mild photoreceptor transduction, but did not lead to the clinical rescue of photopic vision, while day-blind sheep treated with a subretinal injection exhibited functional recovery of photopic vision. Transgene messenger RNA levels in retinas of intravitreally treated eyes amounted to 4-23% of the endogenous CNGA3 levels, indicating that expression levels >23% are needed to achieve clinical rescue. Overall, our results indicate intravitreal injections of AAV2.7m8 transduce ovine photoreceptors, but not with sufficient efficacy to achieve clinical rescue in CNGA3 mutant sheep.
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Affiliation(s)
- M Ross
- Koret School of Veterinary Medicine, Hebrew University of Jerusalem, Rehovot, Israel
| | - A Obolensky
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - E Averbukh
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - M Desrosiers
- Department of Therapeutics, Institut de la Vision, Paris, France
| | - R Ezra-Elia
- Koret School of Veterinary Medicine, Hebrew University of Jerusalem, Rehovot, Israel
| | - H Honig
- Department of Animal Science, ARO, The Volcani Center, Rishon LeZion, Israel
| | - E Yamin
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - A Rosov
- Department of Animal Science, ARO, The Volcani Center, Rishon LeZion, Israel
| | - H Dvir
- Department of Animal Science, ARO, The Volcani Center, Rishon LeZion, Israel
| | - E Gootwine
- Department of Animal Science, ARO, The Volcani Center, Rishon LeZion, Israel
| | - E Banin
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - D Dalkara
- Department of Therapeutics, Institut de la Vision, Paris, France
| | - R Ofri
- Koret School of Veterinary Medicine, Hebrew University of Jerusalem, Rehovot, Israel.
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7
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Suh S, Choi EH, Raguram A, Liu DR, Palczewski K. Precision genome editing in the eye. Proc Natl Acad Sci U S A 2022; 119:e2210104119. [PMID: 36122230 PMCID: PMC9522375 DOI: 10.1073/pnas.2210104119] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
CRISPR-Cas-based genome editing technologies could, in principle, be used to treat a wide variety of inherited diseases, including genetic disorders of vision. Programmable CRISPR-Cas nucleases are effective tools for gene disruption, but they are poorly suited for precisely correcting pathogenic mutations in most therapeutic settings. Recently developed precision genome editing agents, including base editors and prime editors, have enabled precise gene correction and disease rescue in multiple preclinical models of genetic disorders. Additionally, new delivery technologies that transiently deliver precision genome editing agents in vivo offer minimized off-target editing and improved safety profiles. These improvements to precision genome editing and delivery technologies are expected to revolutionize the treatment of genetic disorders of vision and other diseases. In this Perspective, we describe current preclinical and clinical genome editing approaches for treating inherited retinal degenerative diseases, and we discuss important considerations that should be addressed as these approaches are translated into clinical practice.
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Affiliation(s)
- Susie Suh
- Gavin Herbert Eye Institute, Department of Ophthalmology, University of California, Irvine, CA 92697
| | - Elliot H. Choi
- Gavin Herbert Eye Institute, Department of Ophthalmology, University of California, Irvine, CA 92697
| | - Aditya Raguram
- Merkin Institute of Transformative Technologies in Healthcare, Broad Institute of MIT and Harvard, Cambridge, MA 02142
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA 02138
| | - David R. Liu
- Merkin Institute of Transformative Technologies in Healthcare, Broad Institute of MIT and Harvard, Cambridge, MA 02142
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA 02138
| | - Krzysztof Palczewski
- Gavin Herbert Eye Institute, Department of Ophthalmology, University of California, Irvine, CA 92697
- Department of Physiology and Biophysics, University of California, Irvine, CA 92697
- Department of Chemistry, University of California, Irvine, CA 92697
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697
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8
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In Vivo and Ex Vivo Gene Electrotransfer in Ophthalmological Disorders. Biomedicines 2022; 10:biomedicines10081889. [PMID: 36009435 PMCID: PMC9405572 DOI: 10.3390/biomedicines10081889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 07/25/2022] [Accepted: 08/02/2022] [Indexed: 11/16/2022] Open
Abstract
The aim of this document is to present an overview of gene electrotransfer in ophthalmological disorders. In order to ensure an adequate variety of the assessed studies, several electronic databases were considered and studies published between January 1998 and December 2021 were analysed. Three investigators carried out data extraction and analysis, focusing on both technical (i.e., electrical protocol, type of electrode, plasmid) and medical (i.e., type of study, threated disease) aspects and highlighting the main differences in terms of results obtained. Moreover, the IGEA experience in the project “Transposon-based, targeted ex vivo gene therapy to treat age-related macular degeneration” (TargetAMD) was reported in the results section. No clinical trial was found on international literature and on ClinicalTrials.gov. Twelve preclinical studies were found including in vivo and ex-vivo applications. The studied showed that electrotransfer could be very efficient for plasmid DNA transfection. Many attempts such as modification of the electric field, buffers and electrodes have been made and the optimization of electric field setting seems to be very important. Using this technique, gene replacement can be designed in cases of retinal inheritance or corneal disease and a wide range of human eye diseases could, in the future, benefitfrom these gene therapy technologies.
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9
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Rudnick ND, Kim LA, Comander J. Adeno-associated Viral Vectors in the Retina: Delivering Gene Therapy to the Right Destination. Int Ophthalmol Clin 2022; 62:215-229. [PMID: 35325920 DOI: 10.1097/iio.0000000000000416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
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10
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Ladha R, Caspers LE, Willermain F, de Smet MD. Subretinal Therapy: Technological Solutions to Surgical and Immunological Challenges. Front Med (Lausanne) 2022; 9:846782. [PMID: 35402424 PMCID: PMC8985755 DOI: 10.3389/fmed.2022.846782] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Accepted: 02/21/2022] [Indexed: 12/12/2022] Open
Abstract
Recent advances in ocular gene and cellular therapy rely on precisely controlled subretinal delivery. Due to its inherent limitations, manual delivery can lead to iatrogenic damage to the retina, the retinal pigment epithelium, favor reflux into the vitreous cavity. In addition, it suffers from lack of standardization, variability in delivery and the need to maintain proficiency. With or without surgical damage, an eye challenged with an exogenous viral vector or transplanted cells will illicit an immune response. Understanding how such a response manifests itself and to what extent immune privilege protects the eye from a reaction can help in anticipating short- and long-term consequences. Avoidance of spillover from areas of immune privilege to areas which either lack or have less protection should be part of any mitigation strategy. In that regard, robotic technology can provide reproducible, standardized delivery which is not dependent on speed of injection. The advantages of microprecision medical robotic technology for precise targeted deliveries are discussed.
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Affiliation(s)
- Reza Ladha
- Departments of Ophthalmology, Centre Hospitalier Universitaire Saint-Pierre and Brugmann, Brussels, Belgium
- Université Libre de Bruxelles, Brussels, Belgium
- *Correspondence: Reza Ladha
| | - Laure E. Caspers
- Departments of Ophthalmology, Centre Hospitalier Universitaire Saint-Pierre and Brugmann, Brussels, Belgium
- Université Libre de Bruxelles, Brussels, Belgium
| | - François Willermain
- Departments of Ophthalmology, Centre Hospitalier Universitaire Saint-Pierre and Brugmann, Brussels, Belgium
- Université Libre de Bruxelles, Brussels, Belgium
| | - Marc D. de Smet
- Department of Ophthalmology, Leiden University, Leiden, Netherlands
- Preceyes B.V., Eindhoven, Netherlands
- MIOS SA, Lausanne, Switzerland
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Muhuri M, Levy DI, Schulz M, McCarty D, Gao G. Durability of transgene expression after rAAV gene therapy. Mol Ther 2022; 30:1364-1380. [PMID: 35283274 PMCID: PMC9077371 DOI: 10.1016/j.ymthe.2022.03.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 01/09/2022] [Accepted: 03/07/2022] [Indexed: 11/19/2022] Open
Abstract
Recombinant adeno-associated virus (rAAV) gene therapy has the potential to transform the lives of patients with certain genetic disorders by increasing or restoring function to affected tissues. Following the initial establishment of transgene expression, it is unknown how long the therapeutic effect will last, although animal and emerging human data show that expression can be maintained for more than 10 years. The durability of therapeutic response is key to long-term treatment success, especially since immune responses to rAAV vectors may prevent re-dosing with the same therapy. This review explores the non-immunological and immunological processes that may limit or improve durability and the strategies that can be used to increase the duration of the therapeutic effect.
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Affiliation(s)
- Manish Muhuri
- Horae Gene Therapy Center, University of Massachusetts Medical School, Worcester, MA, USA; Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA, USA
| | | | | | | | - Guangping Gao
- Horae Gene Therapy Center, University of Massachusetts Medical School, Worcester, MA, USA; Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA, USA; Li Weibo Institute for Rare Diseases Research, University of Massachusetts Medical School, Worcester, MA, USA.
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12
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Duncan GA. Integrative approaches to enhance adeno-associated viral gene delivery. J Control Release 2021; 341:44-50. [PMID: 34785314 DOI: 10.1016/j.jconrel.2021.11.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 11/09/2021] [Indexed: 12/12/2022]
Abstract
To meet the present and future challenges in achieving therapeutic in vivo gene delivery using adeno-associated virus (AAV), new innovations are required that integrate knowledge from disciplines ranging from biomaterials science, drug delivery, immunobiology, to tissue engineering. One of the foremost challenges remaining is in addressing pre-existing and therapy induced immune responses to AAV which significantly limit its therapeutic effect. In addition, functional correction of diseased tissues will depend on the ability of AAVs to retain activity after local or systemic administration and broadly distribute in target tissues. In this contribution to the Orations - New Horizons of the Journal of Controlled Release, I will introduce new concepts and potential strategies pursued by our lab and others to better understand and overcome these hurdles to effective AAV gene therapy. These multi-disciplinary approaches may open the door to the creation of precision gene therapies to treat heavily burdensome and often deadly diseases.
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Affiliation(s)
- Gregg A Duncan
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA; Biophysics Program, University of Maryland, College Park, MD 20742, USA.
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13
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Martinez Velazquez LA, Ballios BG. The Next Generation of Molecular and Cellular Therapeutics for Inherited Retinal Disease. Int J Mol Sci 2021; 22:ijms222111542. [PMID: 34768969 PMCID: PMC8583900 DOI: 10.3390/ijms222111542] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 10/13/2021] [Accepted: 10/14/2021] [Indexed: 12/26/2022] Open
Abstract
Inherited retinal degenerations (IRDs) are a diverse group of conditions that are often characterized by the loss of photoreceptors and blindness. Recent innovations in molecular biology and genomics have allowed us to identify the causative defects behind these dystrophies and to design therapeutics that target specific mechanisms of retinal disease. Recently, the FDA approved the first in vivo gene therapy for one of these hereditary blinding conditions. Current clinical trials are exploring new therapies that could provide treatment for a growing number of retinal dystrophies. While the field has had early success with gene augmentation strategies for treating retinal disease based on loss-of-function mutations, many novel approaches hold the promise of offering therapies that span the full spectrum of causative mutations and mechanisms. Here, we provide a comprehensive review of the approaches currently in development including a discussion of retinal neuroprotection, gene therapies (gene augmentation, gene editing, RNA modification, optogenetics), and regenerative stem or precursor cell-based therapies. Our review focuses on technologies that are being developed for clinical translation or are in active clinical trials and discusses the advantages and limitations for each approach.
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Affiliation(s)
| | - Brian G. Ballios
- Department of Ophthalmology and Vision Sciences, Temerty Faculty of Medicine, University of Toronto, Toronto, ON M5T 3A9, Canada
- Correspondence:
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14
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Hutt JA, Assaf BT, Bolon B, Cavagnaro J, Galbreath E, Grubor B, Kattenhorn LM, Romeike A, Whiteley LO. Scientific and Regulatory Policy Committee Points to Consider: Nonclinical Research and Development of In Vivo Gene Therapy Products, Emphasizing Adeno-Associated Virus Vectors. Toxicol Pathol 2021; 50:118-146. [PMID: 34657529 DOI: 10.1177/01926233211041962] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Sequencing of the human genome and numerous advances in molecular techniques have launched the era of genetic medicine. Increasingly precise technologies for genetic modification, manufacturing, and administration of pharmaceutical-grade biologics have proved the viability of in vivo gene therapy (GTx) as a therapeutic modality as shown in several thousand clinical trials and recent approval of several GTx products for treating rare diseases and cancers. In recognition of the rapidly advancing knowledge in this field, the regulatory landscape has evolved considerably to maintain appropriate monitoring of safety concerns associated with this modality. Nonetheless, GTx safety assessment remains complex and is designed on a case-by-case basis that is determined by the disease indication and product attributes. This article describes our current understanding of fundamental biological principles and possible procedures (emphasizing those related to toxicology and toxicologic pathology) needed to support research and development of in vivo GTx products. This article is not intended to provide comprehensive guidance on all GTx modalities but instead provides an overview relevant to in vivo GTx generally by utilizing recombinant adeno-associated virus-based GTx-the most common in vivo GTx platform-to exemplify the main points to be considered in nonclinical research and development of GTx products.
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Affiliation(s)
- Julie A Hutt
- Greenfield Pathology Services, Inc, Greenfield, IN, USA
| | - Basel T Assaf
- Drug Safety Research and Development, Pfizer Inc, Cambridge, MA, USA
| | | | | | | | - Branka Grubor
- Biogen, Preclinical Safety/Comparative Pathology, Cambridge, MA, USA
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15
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Mohana Devi S, Abishek Kumar B, Mahalaxmi I, Balachandar V. Leber's hereditary optic neuropathy: Current approaches and future perspectives on Mesenchymal stem cell-mediated rescue. Mitochondrion 2021; 60:201-218. [PMID: 34454075 DOI: 10.1016/j.mito.2021.08.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 08/03/2021] [Accepted: 08/23/2021] [Indexed: 12/19/2022]
Abstract
Leber's Hereditary Optic Neuropathy (LHON) is an inherited optic nerve disorder. It is a mitochondrially inherited disease due to point mutation in the MT-ND1, MT-ND4, and MT-ND6 genes of mitochondrial DNA (mtDNA) coding for complex I subunit proteins. These mutations affect the assembly of the mitochondrial complex I and hence the electron transport chain leading to mitochondrial dysfunction and oxidative damage. Optic nerve cells like retinal ganglion cells (RGCs) are more sensitive to mitochondrial loss and oxidative damage which results in the progressive degeneration of RGCs at the axonal region of the optic nerve leading to bilateral vision loss. Currently, gene therapy using Adeno-associated viral vector (AAV) is widely studied for the therapeutics application in LHON. Our review highlights the application of cell-based therapy for LHON. Mesenchymal stem cells (MSCs) are known to rescue cells from the pre-apoptotic stage by transferring healthy mitochondria through tunneling nanotubes (TNT) for cellular oxidative function. Empowering the transfer of healthy mitochondria using MSCs may replace the mitochondria with pathogenic mutation and possibly benefit the cells from progressive damage. This review discusses the ongoing research in LHON and mitochondrial transfer mechanisms to explore its scope in inherited optic neuropathy.
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Affiliation(s)
- Subramaniam Mohana Devi
- SN ONGC Department of Genetics and Molecular Biology, Vision Research Foundation, Sankara Nethralaya, Chennai, India.
| | - B Abishek Kumar
- SN ONGC Department of Genetics and Molecular Biology, Vision Research Foundation, Sankara Nethralaya, Chennai, India
| | - Iyer Mahalaxmi
- Livestock Farming and Bioresource Technology, Tamil Nadu, India
| | - Vellingiri Balachandar
- Department of Human Genetics and Molecular Biology, Bharathiar University, Coimbatore, India
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16
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Dhurandhar D, Sahoo NK, Mariappan I, Narayanan R. Gene therapy in retinal diseases: A review. Indian J Ophthalmol 2021; 69:2257-2265. [PMID: 34427196 PMCID: PMC8544052 DOI: 10.4103/ijo.ijo_3117_20] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Over 2 million people worldwide are suffering from gene-related retinal diseases, inherited or acquired, and over 270 genes have been identified which are found to be responsible for these conditions. This review article touches upon the mechanisms of gene therapy, various enzymes of the visual cycle responsible for different genetic diseases, Luxturna—the first US Food and Drug Administration (FDA)-approved therapeutic gene product, and several ongoing trials of gene therapy for age-related macular degeneration. Gene therapy has tremendous potential for retinal conditions due to its ease of accessibility, immune-privileged status, and tight blood-retinal barriers, limiting systemic side effects of the drug. In recent years, advances in gene therapy in retinal conditions have increasing significantly, with progress in cell-specific targeting and transduction efficiency of gene products through the use of adeno-associated viral vectors (AAVs), suggesting that even greater success in future clinical trials is possible.
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Affiliation(s)
- Deven Dhurandhar
- Retina and Uveitis Department, GMR Varalakshmi Campus, LV Prasad Eye Institute, Visakhapatnam, Andhra Pradesh, India
| | - Niroj Kumar Sahoo
- Smt. Kanuri Santhamma Centre for Vitreo-Retinal Diseases, Kallam Anji Reddy Campus, L V Prasad Eye Institute, Hyderabad, Telangana, India
| | - Indumathi Mariappan
- Centre for Ocular Regeneration, Hyderabad Eye Research Foundation, Kallam Anji Reddy Campus, L.V. Prasad Eye Institute, Hyderabad, Telangana, India
| | - Raja Narayanan
- Smt. Kanuri Santhamma Centre for Vitreo-Retinal Diseases, Kallam Anji Reddy Campus, L V Prasad Eye Institute, Hyderabad, Telangana, India
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17
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Mohan RR, Balne PK, Muayad MS, Tripathi R, Sinha NR, Gupta S, An JA, Sinha PR, Hesemann NP. Six-Month In Vivo Safety Profiling of Topical Ocular AVV5-Decorin Gene Transfer. Transl Vis Sci Technol 2021; 10:5. [PMID: 34383877 PMCID: PMC8362634 DOI: 10.1167/tvst.10.10.5] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Purpose A significant remission of corneal fibrosis and neovascularization in rabbit eye in vivo was observed from a tissue-selective localized adeno-associated virus (AAV)5–Decorin (Dcn) gene therapy. This study sought to investigate 6-month toxicity profiling of this gene therapy for the eye in vivo using a rabbit model. Methods A small epithelial scrape followed by corneal drying was performed unilaterally in 12 rabbit eyes and either AAV5–Dcn (n = 6) or naked vector (n = 6) was delivered topically using a cloning cylinder technique. Contralateral eyes served as naïve control (n = 6). Safety and tolerability measurements in live rabbits were performed periodically until month 6 using multimodel clinical ophthalmic imaging tools—a slit lamp, stereomicroscope, and HRT3-RCM in vivo confocal microscope. Thereafter, corneas were excised and subjected to hematoxylin and eosin staining, Mason trichome staining, propidium iodide nuclear staining, and quantitative real-time polymerase chain reaction analyses. Results Clinical eye examinations based on the modified Hackett–McDonald ocular scoring system, and in vivo confocal imaging of the cornea showed no signs of ocular toxicity in rabbit eyes given AAV5–Dcn gene transfer vs control eyes (P > 0.05) through 6 months after treatment. The histologic and molecular analyses showed no significant differences in AAV5–Dcn vs AAV naked or naïve control groups (P > 0.05) and were in accordance with the masked clinical ophthalmic observations showing no abnormalities. Conclusions Topical tissue-targeted localized AAV5–Dcn gene therapy seems to be safe and nontoxic to the rabbit eye in vivo. Translational Relevance AAV5–Dcn gene therapy has the potential to treat corneal fibrosis and neovascularization in vivo safely without significant ocular toxicity.
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Affiliation(s)
- Rajiv R Mohan
- Harry S. Truman Memorial Veterans' Hospital, Columbia, Missouri, USA.,One-Health Vision Research Program, Departments of Veterinary Medicine & Surgery and Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA.,Mason Eye Institute, School of Medicine, University of Missouri, Columbia, Missouri, USA
| | - Praveen K Balne
- Harry S. Truman Memorial Veterans' Hospital, Columbia, Missouri, USA.,One-Health Vision Research Program, Departments of Veterinary Medicine & Surgery and Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA
| | - Maryam S Muayad
- Harry S. Truman Memorial Veterans' Hospital, Columbia, Missouri, USA.,One-Health Vision Research Program, Departments of Veterinary Medicine & Surgery and Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA
| | - Ratnakar Tripathi
- Harry S. Truman Memorial Veterans' Hospital, Columbia, Missouri, USA.,One-Health Vision Research Program, Departments of Veterinary Medicine & Surgery and Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA
| | - Nishant R Sinha
- Harry S. Truman Memorial Veterans' Hospital, Columbia, Missouri, USA.,One-Health Vision Research Program, Departments of Veterinary Medicine & Surgery and Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA
| | - Suneel Gupta
- Harry S. Truman Memorial Veterans' Hospital, Columbia, Missouri, USA.,One-Health Vision Research Program, Departments of Veterinary Medicine & Surgery and Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA
| | - Jella A An
- Harry S. Truman Memorial Veterans' Hospital, Columbia, Missouri, USA.,Mason Eye Institute, School of Medicine, University of Missouri, Columbia, Missouri, USA
| | - Prashant R Sinha
- Harry S. Truman Memorial Veterans' Hospital, Columbia, Missouri, USA.,One-Health Vision Research Program, Departments of Veterinary Medicine & Surgery and Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA
| | - Nathan P Hesemann
- Harry S. Truman Memorial Veterans' Hospital, Columbia, Missouri, USA.,One-Health Vision Research Program, Departments of Veterinary Medicine & Surgery and Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA
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18
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Xu D, Khan MA, Klufas MA, Ho AC. Administration of Ocular Gene Therapy. Int Ophthalmol Clin 2021; 61:131-149. [PMID: 34196321 DOI: 10.1097/iio.0000000000000365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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19
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Murray SJ, Russell KN, Melzer TR, Gray SJ, Heap SJ, Palmer DN, Mitchell NL. Intravitreal gene therapy protects against retinal dysfunction and degeneration in sheep with CLN5 Batten disease. Exp Eye Res 2021; 207:108600. [PMID: 33930398 DOI: 10.1016/j.exer.2021.108600] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 04/12/2021] [Accepted: 04/21/2021] [Indexed: 01/01/2023]
Abstract
Neuronal ceroid lipofuscinoses (NCL; Batten disease) are a group of inherited neurodegenerative diseases primarily affecting children. A common feature across most NCLs is the progressive loss of vision. We performed intravitreal injections of self-complementary AAV9 vectors packaged with either ovine CLN5 or CLN6 into one eye of 3-month-old CLN5-/- or CLN6-/- animals, respectively. Electroretinography (ERG) was performed every month following treatment, and retinal histology was assessed post-mortem in the treated compared to untreated eye. In CLN5-/- animals, ERG amplitudes were normalised in the treated eye whilst the untreated eye declined in a similar manner to CLN5 affected controls. In CLN6-/- animals, ERG amplitudes in both eyes declined over time although the treated eye showed a slower decline. Post-mortem examination revealed significant attenuation of retinal atrophy and lysosomal storage body accumulation in the treated eye compared with the untreated eye in CLN5-/- animals. This proof-of-concept study provides the first observation of efficacious intravitreal gene therapy in a large animal model of NCL. In particular, the single administration of AAV9-mediated intravitreal gene therapy can successfully ameliorate retinal deficits in CLN5-/- sheep. Combining ocular gene therapy with brain-directed therapy presents a promising treatment strategy to be used in future sheep trials aiming to halt neurological and retinal disease in CLN5 Batten disease.
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Affiliation(s)
- Samantha J Murray
- Faculty of Agricultural and Life Sciences, Lincoln University, Lincoln, 7647, New Zealand
| | - Katharina N Russell
- Faculty of Agricultural and Life Sciences, Lincoln University, Lincoln, 7647, New Zealand
| | - Tracy R Melzer
- Department of Medicine, University of Otago, Christchurch and the New Zealand Brain Research Institute, Christchurch, 8011, New Zealand
| | - Steven J Gray
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Stephen J Heap
- McMaster & Heap Veterinary Practice, Christchurch, 8025, New Zealand
| | - David N Palmer
- Faculty of Agricultural and Life Sciences, Lincoln University, Lincoln, 7647, New Zealand; Department of Radiology, University of Otago, Christchurch, 8140, New Zealand
| | - Nadia L Mitchell
- Faculty of Agricultural and Life Sciences, Lincoln University, Lincoln, 7647, New Zealand; Department of Radiology, University of Otago, Christchurch, 8140, New Zealand.
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20
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[Implementation of a new gene therapy in ophthalmology: Regulatory and organizational issues]. J Fr Ophtalmol 2021; 44:730-737. [PMID: 33838946 DOI: 10.1016/j.jfo.2020.10.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 10/20/2020] [Accepted: 10/27/2020] [Indexed: 11/23/2022]
Abstract
Voretigene neparvovec (VN) is the first gene therapy in ophthalmology for patients with RPE65-mediated hereditary retinal dystrophy. It has recently obtained European market approval, which is subject to strict regulatory and organizational conditions for its use. Here, we analyze the main studies supporting the authorization of this new therapy and describe the necessary steps to take at a hospital level for optimal administration to patients following current regulations.
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21
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Hu ML, Edwards TL, O'Hare F, Hickey DG, Wang JH, Liu Z, Ayton LN. Gene therapy for inherited retinal diseases: progress and possibilities. Clin Exp Optom 2021; 104:444-454. [PMID: 33689657 DOI: 10.1080/08164622.2021.1880863] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Inherited retinal diseases (IRDs) comprise a heterogeneous group of genetic disorders affecting the retina. Caused by mutations in over 300 genes, IRDs result in visual impairment due to dysfunction and degeneration of photoreceptors, retinal pigment epithelium, or the choroid. Important photoreceptor IRDs include retinitis pigmentosa and Leber congenital amaurosis. Macular dystrophies include Stargardt and Best disease. Currently, IRDs are largely incurable but the landscape of treatment options is rapidly changing for these diseases which, untreated, result in severe visual impairment and blindness.Advances in DNA delivery to the retina and improved genetic diagnosis of IRDs have led to a new era of research into gene therapy for these vision-threatening disorders. Gene therapy is a compelling approach due to the monogenic nature of most IRDs, with the retina being a favourable target for administering genetic vectors due to its immunoprivileged environment, direct visibility, and multiple methods to assess sensitivity and function. Generally, retinal gene therapy involves a subretinal or intravitreal injection of a viral vector, which infects target cells to deliver a therapeutic gene, or transgene. A gene augmentation strategy introduces a functioning copy of a gene to restore expression of a mutated gene, whereas a gene-editing strategy aims to directly edit and correct the mutation. Common delivery vectors include adeno-associated virus (AAV) and lentivirus.Voretigene neparvovec-rzyl (Luxturna) became the first FDA-approved direct gene therapy in December 2017, and the Australian TGA followed suit in August 2020. More are projected to follow, with clinical trials underway for many other IRDs.This review provides an overview of gene therapy for IRDs, including current progress and challenges. A companion article in this issue details target patient populations for IRD gene therapy, and how optometrists can assist in assessing individuals who may be eligible for current and future therapies.
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Affiliation(s)
- Monica L Hu
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia
| | - Thomas L Edwards
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia.,Department of Surgery (Ophthalmology), Faculty of Medicine, Dentistry and Health Sciences, the University of Melbourne, Melbourne, Australia
| | - Fleur O'Hare
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia.,Department of Surgery (Ophthalmology), Faculty of Medicine, Dentistry and Health Sciences, the University of Melbourne, Melbourne, Australia.,Department of Optometry and Vision Sciences, Faculty of Medicine, Dentistry and Health Sciences, the University of Melbourne, Melbourne, Australia
| | - Doron G Hickey
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia
| | - Jiang-Hui Wang
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia
| | - Zhengyang Liu
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia
| | - Lauren N Ayton
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia.,Department of Surgery (Ophthalmology), Faculty of Medicine, Dentistry and Health Sciences, the University of Melbourne, Melbourne, Australia.,Department of Optometry and Vision Sciences, Faculty of Medicine, Dentistry and Health Sciences, the University of Melbourne, Melbourne, Australia
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22
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Mishra A, Vijayasarathy C, Cukras CA, Wiley HE, Sen HN, Zeng Y, Wei LL, Sieving PA. Immune function in X-linked retinoschisis subjects in an AAV8-RS1 phase I/IIa gene therapy trial. Mol Ther 2021; 29:2030-2040. [PMID: 33601057 DOI: 10.1016/j.ymthe.2021.02.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 01/27/2021] [Accepted: 02/10/2021] [Indexed: 12/12/2022] Open
Abstract
This study explored systemic immune changes in 11 subjects with X-linked retinoschisis (XLRS) in a phase I/IIa adeno-associated virus 8 (AAV8)-RS1 gene therapy trial (ClinicalTrials.gov: NCT02317887). Immune cell proportions and serum analytes were compared to 12 healthy male controls. At pre-dosing baseline the mean CD4/CD8 ratio of XLRS subjects was elevated. CD11c+ myeloid dendritic cells (DCs) and the serum epidermal growth factor (EGF) level were decreased, while CD123+ plasmacytoid DCs and serum interferon (IFN)-γ and tumor necrosis factor (TNF)-α were increased, indicating that the XLRS baseline immune status differs from that of controls. XLRS samples 14 days after AAV8-RS1 administration were compared with the XLRS baseline. Frequency of CD11b+CD11c+ DCc was decreased in 8 of 11 XLRS subjects across all vector doses (1e9-3e11 vector genomes [vg]/eye). CD8+human leukocyte antigen-DR isotype (HLA-DR)+ cytotoxic T cells and CD68+CD80+ macrophages were upregulated in 10 of 11 XLRS subjects, along with increased serum granzyme B in 8 of 11 XLRS subjects and elevated IFN-γ in 9 of 11 XLRS subjects. The six XLRS subjects with ocular inflammation after vector application gave a modestly positive correlation of inflammation score to their respective baseline CD4/CD8 ratios. This exploratory study indicates that XLRS subjects may exhibit a proinflammatory, baseline immune phenotype, and that intravitreal dosing with AAV8-RS1 leads to systemic immune activation with an increase of activated lymphocytes, macrophages, and proinflammatory cytokines.
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Affiliation(s)
- Alaknanda Mishra
- National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | | | - Catherine A Cukras
- National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Henry E Wiley
- National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - H Nida Sen
- National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Yong Zeng
- National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Lisa L Wei
- National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Paul A Sieving
- National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA; Department of Ophthalmology, University of California Davis, Davis, CA 95817, USA.
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Lugin ML, Lee RT, Kwon YJ. Synthetically Engineered Adeno-Associated Virus for Efficient, Safe, and Versatile Gene Therapy Applications. ACS NANO 2020; 14:14262-14283. [PMID: 33073995 DOI: 10.1021/acsnano.0c03850] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Gene therapy directly targets mutations causing disease, allowing for a specific treatment at a molecular level. Adeno-associated virus (AAV) has been of increasing interest as a gene delivery vehicle, as AAV vectors are safe, effective, and capable of eliciting a relatively contained immune response. With the recent FDA approval of two AAV drugs for treating rare genetic diseases, AAV vectors are now on the market and are being further explored for other therapies. While showing promise in immune privileged tissue, the use of AAV for systemic delivery is still limited due to the high prevalence of neutralizing antibodies (nAbs). To avoid nAb-mediated inactivation, engineered AAV vectors with modified protein capsids, materials tethered to the capsid surface, or fully encapsulated in a second, larger carrier have been explored. Many of these engineered AAVs have added benefits, including avoided immune response, overcoming the genome size limit, targeted and stimuli-responsive delivery, and multimodal therapy of two or more therapeutic modalities in one platform. Native and engineered AAV vectors have been tested to treat a broad range of diseases, including spinal muscular atrophy, retinal diseases, cancers, and tissue damage. This review will cover the benefits of AAV as a promising gene vector by itself, the progress and advantages of engineered AAV vectors, particularly synthetically engineered ones, and the current state of their clinical translation in therapy.
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24
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Woodburn KW, Vijay S, Blumenkranz MS. Sight of Action: the Rationale and Evolution of Gene Therapy Approaches to the Treatment of Retinal Diseases. CURRENT OPHTHALMOLOGY REPORTS 2020. [DOI: 10.1007/s40135-020-00255-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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25
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Zhang CJ, Ma Y, Jin ZB. The road to restore vision with photoreceptor regeneration. Exp Eye Res 2020; 202:108283. [PMID: 33010290 DOI: 10.1016/j.exer.2020.108283] [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: 02/17/2020] [Revised: 09/13/2020] [Accepted: 09/24/2020] [Indexed: 12/12/2022]
Abstract
Neuroretinal diseases are the predominant cause of irreversible blindness worldwide, mainly due to photoreceptor loss. Currently, there are no radical treatments to fully reverse the degeneration or even stop the disease progression. Thus, it is urgent to develop new biological therapeutics for these diseases on the clinical side. Stem cell-based treatments have become a promising therapeutic for neuroretinal diseases through the replacement of damaged cells with photoreceptors and some allied cells. To date, considerable efforts have been made to regenerate the diseased retina based on stem cell technology. In this review, we overview the current status of stem cell-based treatments for photoreceptor regeneration, including the major cell sources derived from different stem cells in pre-clinical or clinical trial stages. Additionally, we discuss herein the major challenges ahead for and potential new strategy toward photoreceptor regeneration.
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Affiliation(s)
- Chang-Jun Zhang
- Laboratory for Stem Cell & Retinal Regeneration, The Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China
| | - Ya Ma
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Science Key Laboratory, Beijing, 100730, China
| | - Zi-Bing Jin
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Science Key Laboratory, Beijing, 100730, China.
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26
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Madrakhimov SB, Yang JY, Ahn DH, Han JW, Ha TH, Park TK. Peripapillary Intravitreal Injection Improves AAV-Mediated Retinal Transduction. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2020; 17:647-656. [PMID: 32300611 PMCID: PMC7152690 DOI: 10.1016/j.omtm.2020.03.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 03/23/2020] [Indexed: 12/31/2022]
Abstract
The intravitreal (IVT) injection method is a choice when targeting the inner retina for gene therapy. However, the transduction efficiency of adeno-associated virus (AAV) vectors administered by the IVT route is usually low and may be affected by several factors. To improve the transduction efficiency, we developed a novel illuminated long-needle attached injection system and injected AAV2-CMV (cytomegalovirus)-EGFP in front of the retina in rabbit eyes. Ophthalmological examinations were performed and the levels of pro-inflammatory cytokines in the aqueous humor were assessed at the baseline and 1 month, and the results were compared with those of the conventional injection method. Retinal tissues were used for immunohistochemistry. In the ophthalmological examinations, no significant inflammatory signs were detected in both groups, except for transient, mild hyperemia. In the tissues of the rabbits in the peripapillary injection group, significantly increased GFP expression was detected at the ganglion cell and the inner nuclear layers (p < 0.01). There were no differences between groups in glial activation and expressions of interleukin (IL)-6 and IL-8. These results suggest that peripapillary IVT injection in front of the retina would be safe and efficiently transduce viral vectors into the retina of large animals and is considered as a potential method for use in clinical trials.
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Affiliation(s)
- Sanjar Batirovich Madrakhimov
- Department of Interdisciplinary Program in Biomedical Science, Soonchunhyang Graduate School, Bucheon Hospital, Bucheon, South Korea
- Laboratory for Translational Research on Retinal and Macular Degeneration, Soonchunhyang University Hospital Bucheon, Bucheon, South Korea
| | - Jin Young Yang
- Department of Interdisciplinary Program in Biomedical Science, Soonchunhyang Graduate School, Bucheon Hospital, Bucheon, South Korea
- Laboratory for Translational Research on Retinal and Macular Degeneration, Soonchunhyang University Hospital Bucheon, Bucheon, South Korea
| | - Dong Hyuck Ahn
- Laboratory for Translational Research on Retinal and Macular Degeneration, Soonchunhyang University Hospital Bucheon, Bucheon, South Korea
| | - Jung Woo Han
- Department of Ophthalmology, Soonchunhyang University Hospital Bucheon, Bucheon, South Korea
| | - Tae Ho Ha
- CMLAB, Convergence Technologies for Bio-Medical Science, Seoul, South Korea
| | - Tae Kwann Park
- Department of Interdisciplinary Program in Biomedical Science, Soonchunhyang Graduate School, Bucheon Hospital, Bucheon, South Korea
- Laboratory for Translational Research on Retinal and Macular Degeneration, Soonchunhyang University Hospital Bucheon, Bucheon, South Korea
- Department of Ophthalmology, Soonchunhyang University Hospital Bucheon, Bucheon, South Korea
- Department of Ophthalmology, College of Medicine, Soonchunhyang University, Cheonan, Choongchungnam-do, South Korea
- Ex Lumina Therapeutics and Technologies, Bucheon, South Korea
- Corresponding author: Tae Kwann Park, MD, PhD, Department of Ophthalmology, Soonchunhyang University Hospital Bucheon, #170, Jomaru-ro, Wonmi-gu, Bucheon 14584, South Korea.
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28
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Alvarez-Rivera F, Rey-Rico A, Venkatesan JK, Diaz-Gomez L, Cucchiarini M, Concheiro A, Alvarez-Lorenzo C. Controlled Release of rAAV Vectors from APMA-Functionalized Contact Lenses for Corneal Gene Therapy. Pharmaceutics 2020; 12:pharmaceutics12040335. [PMID: 32283694 PMCID: PMC7238179 DOI: 10.3390/pharmaceutics12040335] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 04/03/2020] [Accepted: 04/07/2020] [Indexed: 12/21/2022] Open
Abstract
As an alternative to eye drops and ocular injections for gene therapy, the aim of this work was to design for the first time hydrogel contact lenses that can act as platforms for the controlled delivery of viral vectors (recombinant adeno-associated virus, rAAV) to the eye in an effective way with improved patient compliance. Hydrogels of hydroxyethyl methacrylate (HEMA) with aminopropyl methacrylamide (APMA) (H1: 40, and H2: 80 mM) or without (Hc: 0 mM) were synthesized, sterilized by steam heat (121 °C, 20 min), and then tested for gene therapy using rAAV vectors to deliver the genes to the cornea. The hydrogels showed adequate light transparency, oxygen permeability, and swelling for use as contact lenses. Loading of viral vectors (rAAV-lacZ, rAAV-RFP, or rAAV-hIGF-I) was carried out at 4 °C to maintain viral vector titer. Release in culture medium was monitored by fluorescence with Cy3-rAAV-lacZ and AAV Titration ELISA. Transduction efficacy was tested through reporter genes lacZ and RFP in human bone marrow derived mesenchymal stem cells (hMSCs). lacZ was detected with X-Gal staining and quantified with Beta-Glo®, and RFP was monitored by fluorescence. The ability of rAAV-hIGF-I-loaded hydrogels to trigger cell proliferation in hMSCs was evaluated by immunohistochemistry. Finally, the ability of rAAV-lacZ-loaded hydrogels to transduce bovine cornea was confirmed through detection with X-Gal staining of β-galactosidase expressed within the tissue.
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Affiliation(s)
- Fernando Alvarez-Rivera
- Departamento de Farmacología, Farmacia y Tecnología Farmacéutica, I+DFarma, Facultad de Farmacia and Health Research Institute of Santiago de Compostela (IDIS), Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain; (F.A.-R.); (L.D.-G.); (A.C.)
| | - Ana Rey-Rico
- Cell Therapy and Regenerative Medicine Unit, Centro de Investigacións Científicas Avanzadas (CICA), Universidade da Coruña, Campus de A Coruña, 15071 A Coruña, Spain;
| | - Jagadeesh K Venkatesan
- Center of Experimental Orthopaedics, Saarland University Medical Center, 66421 Homburg, Germany; (J.K.V.); (M.C.)
| | - Luis Diaz-Gomez
- Departamento de Farmacología, Farmacia y Tecnología Farmacéutica, I+DFarma, Facultad de Farmacia and Health Research Institute of Santiago de Compostela (IDIS), Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain; (F.A.-R.); (L.D.-G.); (A.C.)
| | - Magali Cucchiarini
- Center of Experimental Orthopaedics, Saarland University Medical Center, 66421 Homburg, Germany; (J.K.V.); (M.C.)
| | - Angel Concheiro
- Departamento de Farmacología, Farmacia y Tecnología Farmacéutica, I+DFarma, Facultad de Farmacia and Health Research Institute of Santiago de Compostela (IDIS), Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain; (F.A.-R.); (L.D.-G.); (A.C.)
| | - Carmen Alvarez-Lorenzo
- Departamento de Farmacología, Farmacia y Tecnología Farmacéutica, I+DFarma, Facultad de Farmacia and Health Research Institute of Santiago de Compostela (IDIS), Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain; (F.A.-R.); (L.D.-G.); (A.C.)
- Correspondence: ; Tel.: +34-881815239
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29
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Dieter A, Keppeler D, Moser T. Towards the optical cochlear implant: optogenetic approaches for hearing restoration. EMBO Mol Med 2020; 12:e11618. [PMID: 32227585 PMCID: PMC7136966 DOI: 10.15252/emmm.201911618] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 01/08/2020] [Accepted: 01/28/2020] [Indexed: 12/30/2022] Open
Abstract
Cochlear implants (CIs) are considered the most successful neuroprosthesis as they enable speech comprehension in the majority of half a million CI users suffering from sensorineural hearing loss. By electrically stimulating the auditory nerve, CIs constitute an interface re-connecting the brain and the auditory scene, providing the patient with information regarding the latter. However, since electric current is hard to focus in conductive environments such as the cochlea, the precision of electrical sound encoding-and thus quality of artificial hearing-is limited. Recently, optogenetic stimulation of the cochlea has been suggested as an alternative approach for hearing restoration. Cochlear optogenetics promises increased spectral selectivity of artificial sound encoding, hence improved hearing, as light can conveniently be confined in space to activate the auditory nerve within smaller tonotopic ranges. In this review, we discuss the latest experimental and technological developments of cochlear optogenetics and outline the remaining challenges on the way to clinical translation.
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Affiliation(s)
- Alexander Dieter
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany.,Göttingen Graduate School for Neurosciences, Biophysics and Molecular Biosciences, University of Göttingen, Göttingen, Germany
| | - Daniel Keppeler
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany
| | - Tobias Moser
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany.,Auditory Neuroscience and Optogenetics Laboratory, German Primate Center, Göttingen, Germany.,Auditory Neuroscience Group, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Göttingen, Germany
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30
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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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31
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Trapani I, Auricchio A. Has retinal gene therapy come of age? From bench to bedside and back to bench. Hum Mol Genet 2020; 28:R108-R118. [PMID: 31238338 PMCID: PMC6797000 DOI: 10.1093/hmg/ddz130] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 04/24/2019] [Accepted: 06/07/2019] [Indexed: 02/06/2023] Open
Abstract
Retinal gene therapy has advanced considerably in the past three decades. Initial efforts have been devoted to comprehensively explore and optimize the transduction abilities of gene delivery vectors, define the appropriate intraocular administration routes and obtain evidence of efficacy in animal models of inherited retinal diseases (IRDs). Successful translation in clinical trials of the initial promising proof-of-concept studies led to the important milestone of the first approved product for retinal gene therapy in both US and Europe. The unprecedented clinical development observed during the last decade in the field is however highlighting new challenges that will need to be overcome to bring gene therapy to fruition to a larger patient population within and beyond the realm of IRDs.
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Affiliation(s)
- Ivana Trapani
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy.,Medical Genetics, Department of Translational Medicine, Federico II University, Naples, Italy
| | - Alberto Auricchio
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy.,Department of Advanced Biomedicine, Federico II University, Naples, Italy
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32
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Statement of the DOG, the RG, and the BVA on the therapeutic use of voretigene neparvovec (Luxturna™) in ophthalmology. English version : January 2019. Ophthalmologe 2020; 117:16-24. [PMID: 31089806 DOI: 10.1007/s00347-019-0906-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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33
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[Statement of the German Society of Ophthalmology (DOG), the German Retina Society (RG) and the Professional Association of German Ophthalmologists (BVA) on the therapeutic use of voretigene neparvovec-rzyl (Luxturna™) in ophthalmology : Situation January 2019]. Ophthalmologe 2019; 116:524-533. [PMID: 31016385 DOI: 10.1007/s00347-019-0885-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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34
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Trapani I, Auricchio A. Seeing the Light after 25 Years of Retinal Gene Therapy. Trends Mol Med 2018; 24:669-681. [PMID: 29983335 DOI: 10.1016/j.molmed.2018.06.006] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 05/31/2018] [Accepted: 06/11/2018] [Indexed: 12/25/2022]
Abstract
The retina has been at the forefront of translational gene therapy. Proof-of-concept that gene therapy could restore vision in a large animal led to the initiation of the first successful clinical trials and, in turn, to the recent approval of the first gene therapy product for an ocular disease. As dozens of clinical trials of retinal gene therapy have begun, new challenges are identified, which include delivery of large genes, counteracting gain-of-function mutations, and safe and effective gene transfer to diseased retinas. Advancements in vector design, improvements of delivery routes, and selection of optimal timing for intervention will contribute to extend the initial success of retinal gene therapy to an increasing number of inherited blinding conditions.
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Affiliation(s)
- Ivana Trapani
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy; Medical Genetics, Department of Translational Medicine, Federico II University, Naples, Italy.
| | - Alberto Auricchio
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy; Department of Advanced Biomedicine, Federico II University, Naples, Italy.
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35
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Abstract
The first step in vision is the absorption of photons by the photopigments in cone and rod photoreceptors. After initial amplification within the phototransduction cascade the signal is translated into an electrical signal by the action of cyclic nucleotide-gated (CNG) channels. CNG channels are ligand-gated ion channels that are activated by the binding of cyclic guanosine monophosphate (cGMP) or cyclic adenosine monophosphate (cAMP). Retinal CNG channels transduce changes in intracellular concentrations of cGMP into changes of the membrane potential and the Ca2+ concentration. Structurally, the CNG channels belong to the superfamily of pore-loop cation channels and share a common gross structure with hyperpolarization-activated cyclic nucleotide-gated (HCN) channels and voltage-gated potassium channels (KCN). In this review, we provide an overview on the molecular properties of CNG channels and describe their physiological role in the phototransduction pathways. We also discuss insights into the pathophysiological role of CNG channel proteins that have emerged from the analysis of CNG channel-deficient animal models and human CNG channelopathies. Finally, we summarize recent gene therapy activities and provide an outlook for future clinical application.
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Affiliation(s)
- Stylianos Michalakis
- Center for Integrated Protein Science Munich (CIPSM), Department of Pharmacy-Center for Drug Research, Ludwig-Maximilians-Universität München, Butenandtstr, 5-13, 81377 Munich, Germany.
| | - Elvir Becirovic
- Center for Integrated Protein Science Munich (CIPSM), Department of Pharmacy-Center for Drug Research, Ludwig-Maximilians-Universität München, Butenandtstr, 5-13, 81377 Munich, Germany.
| | - Martin Biel
- Center for Integrated Protein Science Munich (CIPSM), Department of Pharmacy-Center for Drug Research, Ludwig-Maximilians-Universität München, Butenandtstr, 5-13, 81377 Munich, Germany.
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36
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Michalakis S, Schön C, Becirovic E, Biel M. Gene therapy for achromatopsia. J Gene Med 2018; 19. [PMID: 28095637 DOI: 10.1002/jgm.2944] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 01/13/2017] [Accepted: 01/13/2017] [Indexed: 02/02/2023] Open
Abstract
The present review summarizes the current status of achromatopsia (ACHM) gene therapy-related research activities and provides an outlook for their clinical application. ACHM is an inherited eye disease characterized by a congenital absence of cone photoreceptor function. As a consequence, ACHM is associated with strongly impaired daylight vision, photophobia, nystagmus and a lack of color discrimination. Currently, six genes have been linked to ACHM. Up to 80% of the patients carry mutations in the genes CNGA3 and CNGB3 encoding the two subunits of the cone cyclic nucleotide-gated channel. Various animal models of the disease have been established and their characterization has helped to increase our understanding of the pathophysiology associated with ACHM. With the advent of adeno-associated virus vectors as valuable gene delivery tools for retinal photoreceptors, a number of promising gene supplementation therapy programs have been initiated. In recent years, huge progress has been made towards bringing a curative treatment for ACHM into clinics. The first clinical trials are ongoing or will be launched soon and are expected to contribute important data on the safety and efficacy of ACHM gene supplementation therapy.
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Affiliation(s)
- Stylianos Michalakis
- Center for Integrated Protein Science Munich CiPSM and Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Christian Schön
- Center for Integrated Protein Science Munich CiPSM and Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Elvir Becirovic
- Center for Integrated Protein Science Munich CiPSM and Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Martin Biel
- Center for Integrated Protein Science Munich CiPSM and Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
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37
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Mingozzi F, High KA. Overcoming the Host Immune Response to Adeno-Associated Virus Gene Delivery Vectors: The Race Between Clearance, Tolerance, Neutralization, and Escape. Annu Rev Virol 2017; 4:511-534. [PMID: 28961410 DOI: 10.1146/annurev-virology-101416-041936] [Citation(s) in RCA: 136] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Immune responses in gene therapy with adeno-associated virus (AAV) vectors have been the object of almost two decades of study. Although preclinical models helped to define and predict certain aspects of interactions between the vector and the host immune system, most of our current knowledge has come from clinical trials. These studies have allowed development of effective interventions for modulating immunotoxicities associated with vector administration, resulting in therapeutic advances. However, the road to full understanding and effective modulation of immune responses in gene therapy is still long; the determinants of the balance between tolerance and immunogenicity in AAV vector-mediated gene transfer are not fully understood, and effective solutions for overcoming preexisting neutralizing antibodies are still lacking. However, despite these challenges, the goal of reliably delivering effective gene-based treatments is now in sight.
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Affiliation(s)
- Federico Mingozzi
- Genethon and INSERM U951, 91000 Evry, France; .,University Pierre and Marie Curie Paris 6 and INSERM U974, 75651 Paris, France
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38
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Affiliation(s)
- Arthur Planul
- Inserm, Institut de la Vision, UMR S968, 75012 Paris, France;,
- Sorbonne Universités, UPMC Université Paris 6, UMR S968, 75012 Paris, France
- CNRS, UMR 7210, 75012 Paris, France
| | - Deniz Dalkara
- Inserm, Institut de la Vision, UMR S968, 75012 Paris, France;,
- Sorbonne Universités, UPMC Université Paris 6, UMR S968, 75012 Paris, France
- CNRS, UMR 7210, 75012 Paris, France
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39
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Fischer MD, Hickey DG, Singh MS, MacLaren RE. Evaluation of an Optimized Injection System for Retinal Gene Therapy in Human Patients. Hum Gene Ther Methods 2017; 27:150-8. [PMID: 27480111 DOI: 10.1089/hgtb.2016.086] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Many retinal gene therapy clinical trials require subretinal injections of small volumes of adeno-associated viral (AAV) vector solutions in patients with retinal dystrophies, using equipment not specifically designed for this purpose. We therefore evaluated an optimized injection system in order to identify variables that might influence the rate of injection and final dose of vector delivered. An optimized injection system was assembled with a 41G polytetrafluoroethylene tip for retinal gene therapy. Flow rate was recorded at relevant infusion pressures (2-22 psi [14-152 kPa]), different target pressures (0.02-30 mm Hg [0.003-4 kPa]) and temperatures (18°C vs. 36°C) using a semiautomated Accurus(®) Surgical System. Retention of AAV2/8 and AAV2/8(Y733F) vector was quantified after simulating loading/injection with or without 0.001% Pluronic(®) F-68 (PF-68). The optimized injection system provided a linear flow rate (μl/s)-to-infusion pressure (psi) relationship (y = 0.62x; r(2) = 0.99), independent of temperature and pressure changes relevant for intraocular surgery (18-36°C, 0.02-30 mm Hg). Differences in length of 41G polytetrafluoroethylene tips caused significant variation in flow rate (p < 0.001). Use of PF-68 significantly (p < 0.001) reduced loss of vector genomes in the injection system by 55% (AAV2/8) and 52% (AAV2/8(Y733F)). A customized subretinal injection system assembled using equipment currently available in the operating room can deliver a controlled volume of vector at a fixed rate across a range of possible clinical parameters encountered in vitreoretinal surgery. The inclusion of 0.001% PF-68 had a significant effect on the final dose of vector genomes delivered. The described technique is currently used successfully in a clinical trial.
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Affiliation(s)
- M Dominik Fischer
- 1 Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford , Oxford, United Kingdom.,2 Oxford Eye Hospital, Oxford University Hospitals NHS Trust , Oxford, United Kingdom.,3 University Eye Hospital , Centre for Ophthalmology, Tübingen, Germany
| | - Doron G Hickey
- 1 Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford , Oxford, United Kingdom
| | - Mandeep S Singh
- 1 Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford , Oxford, United Kingdom.,2 Oxford Eye Hospital, Oxford University Hospitals NHS Trust , Oxford, United Kingdom.,4 Moorfields Eye Hospital NHS Foundation Trust , Oxford, United Kingdom
| | - Robert E MacLaren
- 1 Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford , Oxford, United Kingdom.,2 Oxford Eye Hospital, Oxford University Hospitals NHS Trust , Oxford, United Kingdom.,4 Moorfields Eye Hospital NHS Foundation Trust , Oxford, United Kingdom
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40
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Cabral T, DiCarlo JE, Justus S, Sengillo JD, Xu Y, Tsang SH. CRISPR applications in ophthalmologic genome surgery. Curr Opin Ophthalmol 2017; 28:252-259. [PMID: 28141764 PMCID: PMC5511789 DOI: 10.1097/icu.0000000000000359] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
PURPOSE OF REVIEW The present review seeks to summarize and discuss the application of clustered regularly interspaced short palindromic repeats (CRISPR)-associated systems (Cas) for genome editing, also called genome surgery, in the field of ophthalmology. RECENT FINDINGS Precision medicine is an emerging approach for disease treatment and prevention that takes into account the variability of an individual's genetic sequence. Various groups have used CRISPR-Cas genome editing to make significant progress in mammalian preclinical models of eye disease, the basic science of eye development in zebrafish, the in vivo modification of ocular tissue, and the correction of stem cells with therapeutic applications. In addition, investigators have creatively used the targeted mutagenic potential of CRISPR-Cas systems to target pathogenic alleles in vitro. SUMMARY Over the past year, CRISPR-Cas genome editing has been used to correct pathogenic mutations in vivo and in transplantable stem cells. Although off-target mutagenesis remains a concern, improvement in CRISPR-Cas technology and careful screening for undesired mutations will likely lead to clinical eye therapeutics employing CRISPR-Cas systems in the near future.
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Affiliation(s)
- Thiago Cabral
- Jonas Children’s Vision Care, and Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University Medical Center, New York, NY, USA
- Edward S Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA
- Department of Ophthalmology, Federal University of Espírito Santo, Vitoria, Brazil
- Department of Ophthalmology, Federal University of Sao Paulo, Sao Paulo, Brazil
| | - James E DiCarlo
- Jonas Children’s Vision Care, and Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University Medical Center, New York, NY, USA
- Edward S Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA
| | - Sally Justus
- Jonas Children’s Vision Care, and Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University Medical Center, New York, NY, USA
- Edward S Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA
| | - Jesse D Sengillo
- Jonas Children’s Vision Care, and Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University Medical Center, New York, NY, USA
- Edward S Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA
- State University of New York Downstate Medical Center, Brooklyn, NY, USA
| | - Yu Xu
- Jonas Children’s Vision Care, and Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University Medical Center, New York, NY, USA
- Edward S Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA
- Department of Ophthalmology, Xin Hua Hospital Affiliated to Shanghai Jiao Tong University
| | - Stephen H Tsang
- Jonas Children’s Vision Care, and Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University Medical Center, New York, NY, USA
- Edward S Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA
- Department of Pathology & Cell Biology, Institute of Human Nutrition, College of Physicians and Surgeons, Columbia University, New York, NY, USA
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41
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Patrício MI, Barnard AR, Orlans HO, McClements ME, MacLaren RE. Inclusion of the Woodchuck Hepatitis Virus Posttranscriptional Regulatory Element Enhances AAV2-Driven Transduction of Mouse and Human Retina. MOLECULAR THERAPY. NUCLEIC ACIDS 2016; 6:198-208. [PMID: 28325286 PMCID: PMC5363497 DOI: 10.1016/j.omtn.2016.12.006] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 12/13/2016] [Accepted: 12/13/2016] [Indexed: 11/26/2022]
Abstract
The woodchuck hepatitis virus posttranscriptional regulatory element (WPRE) has been included in the transgene cassette of adeno-associated virus (AAV) in several gene therapy clinical trials, including those for inherited retinal diseases. However, the extent to which WPRE increases transgene expression in the retina is still unclear. To address this question, AAV2 vectors containing a reporter gene with and without WPRE were initially compared in vitro and subsequently in vivo by subretinal delivery in mice. In both instances, the presence of WPRE led to significantly higher levels of transgene expression as measured by fundus fluorescence, western blot, and immunohistochemistry. The two vectors were further compared in human retinal explants derived from patients undergoing clinically indicated retinectomy, where again the presence of WPRE resulted in an enhancement of reporter gene expression. Finally, an analogous approach using a transgene currently employed in a clinical trial for choroideremia delivered similar results both in vitro and in vivo, confirming that the WPRE effect is transgene independent. Our data fully support the inclusion of WPRE in ongoing and future AAV retinal gene therapy trials, where it may allow a therapeutic effect to be achieved at an overall lower dose of vector.
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Affiliation(s)
- Maria I Patrício
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK; NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford OX3 9DU, UK; Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK
| | - Alun R Barnard
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK; NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford OX3 9DU, UK; Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK
| | - Harry O Orlans
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK; NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford OX3 9DU, UK; Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK; Moorfields Eye Hospital, NHS Foundation Trust, London EC1V 2PD, UK
| | - Michelle E McClements
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK; NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford OX3 9DU, UK
| | - Robert E MacLaren
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK; NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford OX3 9DU, UK; Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK; Moorfields Eye Hospital, NHS Foundation Trust, London EC1V 2PD, UK.
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42
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Gopinath C, Nathar TJ, Ghosh A, Hickstein DD, Nelson EJR. Contemporary Animal Models For Human Gene Therapy Applications. Curr Gene Ther 2016; 15:531-40. [PMID: 26415576 DOI: 10.2174/1566523215666150929110424] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 09/02/2015] [Accepted: 09/08/2015] [Indexed: 01/18/2023]
Abstract
Over the past three decades, gene therapy has been making considerable progress as an alternative strategy in the treatment of many diseases. Since 2009, several studies have been reported in humans on the successful treatment of various diseases. Animal models mimicking human disease conditions are very essential at the preclinical stage before embarking on a clinical trial. In gene therapy, for instance, they are useful in the assessment of variables related to the use of viral vectors such as safety, efficacy, dosage and localization of transgene expression. However, choosing a suitable disease-specific model is of paramount importance for successful clinical translation. This review focuses on the animal models that are most commonly used in gene therapy studies, such as murine, canine, non-human primates, rabbits, porcine, and a more recently developed humanized mice. Though small and large animals both have their own pros and cons as disease-specific models, the choice is made largely based on the type and length of study performed. While small animals with a shorter life span could be well-suited for degenerative/aging studies, large animals with longer life span could suit longitudinal studies and also help with dosage adjustments to maximize therapeutic benefit. Recently, humanized mice or mouse-human chimaeras have gained interest in the study of human tissues or cells, thereby providing a more reliable understanding of therapeutic interventions. Thus, animal models are of great importance with regard to testing new vector technologies in vivo for assessing safety and efficacy prior to a gene therapy clinical trial.
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Chrenek MA, Nickerson JM, Boatright JH. Clustered Regularly Interspaced Short Palindromic Repeats: Challenges in Treating Retinal Disease. Asia Pac J Ophthalmol (Phila) 2016; 5:304-8. [PMID: 27488072 PMCID: PMC4975549 DOI: 10.1097/apo.0000000000000225] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Ophthalmic researchers and clinicians arguably have led the way for safe, effective gene therapy, most notably with adeno-associated viral gene supplementation in the treatment for patients with Leber congenital amaurosis type 2 with mutations in the RPE65 gene. These successes notwithstanding, most other genetic retinal disease will be refractory to supplementation. The ideal gene therapy approach would correct gene mutations to restore normal function in the affected cells. Gene editing in which a mutant allele is inactivated or converted to sequence that restores normal function is hypothetically one such approach. Such editing involves site-specific digestion of mutant genomic DNA followed by repair. Previous experimental approaches were hampered by inaccurate and high rates of off-site lesioning and by overall low digestion rates. A new tool, clustered regularly interspaced short palindromic repeats coupled with the nuclease Cas9, may address both shortcomings. Some of the many challenges that must be addressed in moving clustered regularly interspaced short palindromic repeats coupled with the nuclease Cas9 therapies to the ophthalmic clinic are discussed here.
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Affiliation(s)
- Micah A. Chrenek
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, Georgia
| | - John M. Nickerson
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, Georgia
| | - Jeffrey H. Boatright
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, Georgia
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, Decatur, Georgia
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Abstract
Virus-mediated transfer of genes encoding the mechanotransducer channel candidates TMC1 and TMC2 into hair cells of the ear partially restores hearing in animal models of human genetic deafness (Askew et al., this issue).
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Affiliation(s)
- Tobias Moser
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, 37099 Göttingen, Germany. Synaptic Nanophysiology Group, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany. Auditory Neuroscience Group, German Primate Center, Göttingen, Germany. Auditory Neuroscience Group, Max Planck Institute for Experimental Medicine, Göttingen, Germany. Collaborative Research Center 889, University of Göttingen, Göttingen, Germany
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Fischer MD. On Retinal Gene Therapy. Ophthalmologica 2016; 236:1-7. [PMID: 27119148 DOI: 10.1159/000445782] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Accepted: 03/18/2016] [Indexed: 11/19/2022]
Abstract
Mutations in a large number of genes cause retinal degeneration and blindness with no cure currently available. Retinal gene therapy has evolved over the last decades to become a promising new treatment paradigm for these rare disorders. This article reflects on the ideas and concepts arising from basic science towards the translation of retinal gene therapy into the clinical realm. It describes the advances and present thinking on the efficacy of current clinical trials and discusses potential roadblocks and solutions for the future of retinal gene therapy.
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Affiliation(s)
- M Dominik Fischer
- University Eye Hospital, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
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Boyd RF, Boye SL, Conlon TJ, Erger KE, Sledge DG, Langohr IM, Hauswirth WW, Komáromy AM, Boye SE, Petersen-Jones SM, Bartoe JT. Reduced retinal transduction and enhanced transgene-directed immunogenicity with intravitreal delivery of rAAV following posterior vitrectomy in dogs. Gene Ther 2016; 23:548-56. [PMID: 27052802 DOI: 10.1038/gt.2016.31] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Revised: 02/19/2016] [Accepted: 02/29/2016] [Indexed: 12/22/2022]
Abstract
Adeno-associated virus (AAV) vector-based gene therapy is a promising treatment strategy for delivery of neurotrophic transgenes to retinal ganglion cells (RGCs) in glaucoma patients. Retinal distribution of transgene expression following intravitreal injection (IVT) of AAV is variable in animal models and the vitreous humor may represent a barrier to initial vector penetration. The primary goal of our study was to investigate the effect of prior core vitrectomy with posterior hyaloid membrane peeling on pattern and efficiency of transduction of a capsid amino acid substituted AAV2 vector, carrying the green fluorescent protein (GFP) reporter transgene following IVT in dogs. When progressive intraocular inflammation developed starting 4 weeks post IVT, the study plan was modified to allow detailed characterization of the etiology as a secondary goal. Unexpectedly, surgical vitrectomy was found to significantly limit transduction, whereas in non-vitrectomized eyes transduction efficiency reached upwards to 37.3% of RGC layer cells. The developing retinitis was characterized by mononuclear cell infiltrates resulting from a delayed-type hypersensitivity reaction, which we suspect was directed at the GFP transgene. Our results, in a canine large animal model, support caution when considering surgical vitrectomy before IVT for retinal gene therapy in patients, as prior vitrectomy appears to significantly reduce transduction efficiency and may predispose the patient to development of vector-induced immune reactions.
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Affiliation(s)
- R F Boyd
- Department of Small Animal Clinical Sciences, Michigan State University, East Lansing, MI, USA
| | - S L Boye
- Department of Ophthalmology, University of Florida College of Medicine, Gainesville, FL, USA
| | - T J Conlon
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL, USA
| | - K E Erger
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL, USA
| | - D G Sledge
- Diagnostic Center for Population and Animal Health, Michigan State University, East Lansing, MI, USA
| | - I M Langohr
- Diagnostic Center for Population and Animal Health, Michigan State University, East Lansing, MI, USA
| | - W W Hauswirth
- Department of Ophthalmology, University of Florida College of Medicine, Gainesville, FL, USA
| | - A M Komáromy
- Department of Small Animal Clinical Sciences, Michigan State University, East Lansing, MI, USA
| | - S E Boye
- Department of Ophthalmology, University of Florida College of Medicine, Gainesville, FL, USA
| | - S M Petersen-Jones
- Department of Small Animal Clinical Sciences, Michigan State University, East Lansing, MI, USA
| | - J T Bartoe
- Department of Small Animal Clinical Sciences, Michigan State University, East Lansing, MI, USA
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Büning H, Hacker UT. Inhibitors of Angiogenesis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 917:261-85. [DOI: 10.1007/978-3-319-32805-8_12] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Tse LV, Moller-Tank S, Asokan A. Strategies to circumvent humoral immunity to adeno-associated viral vectors. Expert Opin Biol Ther 2015; 15:845-55. [PMID: 25985812 DOI: 10.1517/14712598.2015.1035645] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
INTRODUCTION Recent success in gene therapy of certain monogenic diseases in the clinic has infused enthusiasm into the continued development of recombinant adeno-associated viral (AAV) vectors as next-generation biologics. However, progress in clinical trials has also highlighted the challenges posed by the host humoral immune response to AAV vectors. Specifically, while pre-existing neutralizing antibodies (NAbs) limit the cohort of eligible patients, NAb generation following treatment prevents vector re-dosing. AREAS COVERED In this review, we discuss a spectrum of complementary strategies that can help circumvent the host humoral immune response to AAV. EXPERT OPINION Specifically, we present a dual perspective, that is, vector versus host, and highlight the clinical attributes, potential caveats and limitations as well as complementarity associated with the various approaches.
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Affiliation(s)
- Longping V Tse
- University of North Carolina, Gene Therapy Center , CB#7352, Thurston Building, Chapel Hill, NC 27599 , USA
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Local and systemic responses following intravitreous injection of AAV2-encoded modified Volvox channelrhodopsin-1 in a genetically blind rat model. Gene Ther 2015; 23:158-66. [PMID: 26440056 DOI: 10.1038/gt.2015.99] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Revised: 08/11/2015] [Accepted: 09/04/2015] [Indexed: 01/22/2023]
Abstract
We previously designed a modified channelrhodopsin-1 (mVChR1) protein chimera with a broader action than that of Chlamydomonas channelrhodopsin-2 and reported that its transduction into retinal ganglion cells can restore visual function in genetically blind, dystrophic Royal College of Surgeons (RCS) rats, with photostimuli ranging from 486 to 640 nm. In the current study, we sought to investigate the safety and influence of mVChR1 transgene expression. Adeno-associated virus type 2 encoding mVChR1 was administered by intravitreous injection into dystrophic RCS rats. Reverse-transcription PCR was used to monitor virus and transgene dissemination and the results demonstrated that their expression was restricted specifically within the eye tissues, and not in non-target organs. Moreover, examination of the blood, plasma and serum revealed that no excess immunoreactivity was present, as determined using standard clinical hematological parameters. Serum antibodies targeting the recombinant adeno-associated virus (rAAV) capsid increased after the injection; however, no increase in mVChR1 antibody was detected during the observation period. In addition, retinal histological examination showed no signs of inflammation in rAAV-injected rats. In conclusion, our results demonstrate that mVChR1 can be exogenously expressed without harmful immunological reactions in vivo. These findings will aid in studies of AAV gene transfer to restore vision in late-stage retinitis pigmentosa.
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Retinal gene delivery by adeno-associated virus (AAV) vectors: Strategies and applications. Eur J Pharm Biopharm 2015; 95:343-52. [DOI: 10.1016/j.ejpb.2015.01.009] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Revised: 01/10/2015] [Accepted: 01/12/2015] [Indexed: 11/20/2022]
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