1
|
Wang JH, Gessler DJ, Zhan W, Gallagher TL, Gao G. Adeno-associated virus as a delivery vector for gene therapy of human diseases. Signal Transduct Target Ther 2024; 9:78. [PMID: 38565561 PMCID: PMC10987683 DOI: 10.1038/s41392-024-01780-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 02/08/2024] [Accepted: 02/19/2024] [Indexed: 04/04/2024] Open
Abstract
Adeno-associated virus (AAV) has emerged as a pivotal delivery tool in clinical gene therapy owing to its minimal pathogenicity and ability to establish long-term gene expression in different tissues. Recombinant AAV (rAAV) has been engineered for enhanced specificity and developed as a tool for treating various diseases. However, as rAAV is being more widely used as a therapy, the increased demand has created challenges for the existing manufacturing methods. Seven rAAV-based gene therapy products have received regulatory approval, but there continue to be concerns about safely using high-dose viral therapies in humans, including immune responses and adverse effects such as genotoxicity, hepatotoxicity, thrombotic microangiopathy, and neurotoxicity. In this review, we explore AAV biology with an emphasis on current vector engineering strategies and manufacturing technologies. We discuss how rAAVs are being employed in ongoing clinical trials for ocular, neurological, metabolic, hematological, neuromuscular, and cardiovascular diseases as well as cancers. We outline immune responses triggered by rAAV, address associated side effects, and discuss strategies to mitigate these reactions. We hope that discussing recent advancements and current challenges in the field will be a helpful guide for researchers and clinicians navigating the ever-evolving landscape of rAAV-based gene therapy.
Collapse
Affiliation(s)
- Jiang-Hui Wang
- Horae Gene Therapy Center, University of Massachusetts Chan Medical School, Worcester, MA, 01605, USA
- Department of Microbiology and Physiological Systems, University of Massachusetts Chan Medical School, Worcester, MA, 01605, USA
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, 3002, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, East Melbourne, VIC, 3002, Australia
| | - Dominic J Gessler
- Horae Gene Therapy Center, University of Massachusetts Chan Medical School, Worcester, MA, 01605, USA
- Department of Microbiology and Physiological Systems, University of Massachusetts Chan Medical School, Worcester, MA, 01605, USA
- Department of Neurological Surgery, University of Massachusetts Chan Medical School, Worcester, MA, 01605, USA
- Department of Neurosurgery, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Wei Zhan
- Horae Gene Therapy Center, University of Massachusetts Chan Medical School, Worcester, MA, 01605, USA
- Department of Microbiology and Physiological Systems, University of Massachusetts Chan Medical School, Worcester, MA, 01605, USA
- Department of Medicine, University of Massachusetts Chan Medical School, Worcester, MA, 01605, USA
- Li Weibo Institute for Rare Diseases Research, University of Massachusetts Chan Medical School, Worcester, MA, 01605, USA
| | - Thomas L Gallagher
- Horae Gene Therapy Center, University of Massachusetts Chan Medical School, Worcester, MA, 01605, USA
| | - Guangping Gao
- Horae Gene Therapy Center, University of Massachusetts Chan Medical School, Worcester, MA, 01605, USA.
- Department of Microbiology and Physiological Systems, University of Massachusetts Chan Medical School, Worcester, MA, 01605, USA.
- Li Weibo Institute for Rare Diseases Research, University of Massachusetts Chan Medical School, Worcester, MA, 01605, USA.
| |
Collapse
|
2
|
Mouzannar K, Schauer A, Liang TJ. The Post-Transcriptional Regulatory Element of Hepatitis B Virus: From Discovery to Therapy. Viruses 2024; 16:528. [PMID: 38675871 PMCID: PMC11055085 DOI: 10.3390/v16040528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 03/26/2024] [Accepted: 03/27/2024] [Indexed: 04/28/2024] Open
Abstract
The post-transcriptional regulatory element (PRE) is present in all HBV mRNAs and plays a major role in their stability, nuclear export, and enhancement of viral gene expression. Understanding PRE's structure, function, and mode of action is essential to leverage its potential as a therapeutic target. A wide range of PRE-based reagents and tools have been developed and assessed in preclinical and clinical settings for therapeutic and biotechnology applications. This manuscript aims to provide a systematic review of the characteristics and mechanism of action of PRE, as well as elucidating its current applications in basic and clinical research. Finally, we discuss the promising opportunities that PRE may provide to antiviral development, viral biology, and potentially beyond.
Collapse
Affiliation(s)
- Karim Mouzannar
- Liver Diseases Branch, National Institute of Diabetics and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA;
| | | | - T. Jake Liang
- Liver Diseases Branch, National Institute of Diabetics and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA;
| |
Collapse
|
3
|
Guan X, Pei Y, Song J. DNA-Based Nonviral Gene Therapy─Challenging but Promising. Mol Pharm 2024; 21:427-453. [PMID: 38198640 DOI: 10.1021/acs.molpharmaceut.3c00907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2024]
Abstract
Over the past decades, significant progress has been made in utilizing nucleic acids, including DNA and RNA molecules, for therapeutic purposes. For DNA molecules, although various DNA delivery systems have been established, viral vector systems are the go-to choice for large-scale commercial applications. However, viral systems have certain disadvantages such as immune response, limited payload capacity, insertional mutagenesis and pre-existing immunity. In contrast, nonviral systems are less immunogenic, not size limited, safer, and easier for manufacturing compared with viral systems. What's more, nonviral DNA vectors have demonstrated their capacity to mediate specific protein expression in vivo for diverse therapeutic objectives containing a wide range of diseases such as cancer, rare diseases, neurodegenerative diseases, and infectious diseases, yielding promising therapeutic outcomes. However, exogenous plasmid DNA is prone to degrade and has poor immunogenicity in vivo. Thus, various strategies have been developed: (i) designing novel plasmids with special structures, (ii) optimizing plasmid sequences for higher expression, and (iii) developing more efficient nonviral DNA delivery systems. Based on these strategies, many interesting clinical results have been reported. This Review discusses the development of DNA-based nonviral gene therapy, including novel plasmids, nonviral delivery systems, clinical advances, and prospects. These developments hold great potential for enhancing the efficacy and safety of nonviral gene therapy and expanding its applications in the treatment of various diseases.
Collapse
Affiliation(s)
- Xiaocai Guan
- Institute of Nano Biomedicine and Engineering, Department of Instrument Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yufeng Pei
- Institute of Basic Medicine and Cancer (IBMC), Chinese Academy of Sciences, The Cancer Hospital of the University of Chinese Academy of Sciences, Hangzhou 310022, China
| | - Jie Song
- Institute of Nano Biomedicine and Engineering, Department of Instrument Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
- Institute of Basic Medicine and Cancer (IBMC), Chinese Academy of Sciences, The Cancer Hospital of the University of Chinese Academy of Sciences, Hangzhou 310022, China
| |
Collapse
|
4
|
MacLaren RE, Fischer MD, Gow JA, Lam BL, Sankila EMK, Girach A, Panda S, Yoon D, Zhao G, Pennesi ME. Subretinal timrepigene emparvovec in adult men with choroideremia: a randomized phase 3 trial. Nat Med 2023; 29:2464-2472. [PMID: 37814062 PMCID: PMC10579095 DOI: 10.1038/s41591-023-02520-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 07/28/2023] [Indexed: 10/11/2023]
Abstract
Choroideremia is a rare, X-linked retinal degeneration resulting in progressive vision loss. A randomized, masked, phase 3 clinical trial evaluated the safety and efficacy over 12 months of follow-up in adult males with choroideremia randomized to receive a high-dose (1.0 × 1011 vector genomes (vg); n = 69) or low-dose (1.0 × 1010 vg; n = 34) subretinal injection of the AAV2-vector-based gene therapy timrepigene emparvovec versus non-treated control (n = 66). Most treatment-emergent adverse events were mild or moderate. The trial did not meet its primary endpoint of best-corrected visual acuity (BCVA) improvement. In the primary endpoint analysis, three of 65 participants (5%) in the high-dose group, one of 34 (3%) participants in the low-dose group and zero of 62 (0%) participants in the control group had ≥15-letter Early Treatment Diabetic Retinopathy Study (ETDRS) improvement from baseline BCVA at 12 months (high dose, P = 0.245 versus control; low dose, P = 0.354 versus control). As the primary endpoint was not met, key secondary endpoints were not tested for significance. In a key secondary endpoint, nine of 65 (14%), six of 35 (18%) and one of 62 (2%) participants in the high-dose, low-dose and control groups, respectively, experienced ≥10-letter ETDRS improvement from baseline BCVA at 12 months. Potential opportunities to enhance future gene therapy studies for choroideremia include optimization of entry criteria (more preserved retinal area), surgical techniques and clinical endpoints. EudraCT registration: 2015-003958-41 .
Collapse
Affiliation(s)
- Robert E MacLaren
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, UK.
- Oxford University Hospitals NIHR Biomedical Research Centre, Oxford, UK.
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK.
| | - M Dominik Fischer
- University Eye Hospital Tübingen, Center for Ophthalmology, Tübingen, Germany
| | | | - Byron L Lam
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
| | | | - Aniz Girach
- Formerly of Nightstar Therapeutics, London, UK
| | | | | | | | - Mark E Pennesi
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA
| |
Collapse
|
5
|
Abdalla Elsayed MEA, Taylor LJ, Josan AS, Fischer MD, MacLaren RE. Choroideremia: The Endpoint Endgame. Int J Mol Sci 2023; 24:14354. [PMID: 37762657 PMCID: PMC10532430 DOI: 10.3390/ijms241814354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 08/25/2023] [Accepted: 09/09/2023] [Indexed: 09/29/2023] Open
Abstract
Choroideremia is an X-linked retinal degeneration resulting from the progressive, centripetal loss of photoreceptors and choriocapillaris, secondary to the degeneration of the retinal pigment epithelium. Affected individuals present in late childhood or early teenage years with nyctalopia and progressive peripheral visual loss. Typically, by the fourth decade, the macula and fovea also degenerate, resulting in advanced sight loss. Currently, there are no approved treatments for this condition. Gene therapy offers the most promising therapeutic modality for halting or regressing functional loss. The aims of the current review are to highlight the lessons learnt from clinical trials in choroideremia, review endpoints, and propose a future strategy for clinical trials.
Collapse
Affiliation(s)
- Maram E. A. Abdalla Elsayed
- Oxford Eye Hospital, Oxford University Hospitals National Health Service Foundation Trust, Oxford OX3 9DU, UK
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
| | - Laura J. Taylor
- Oxford Eye Hospital, Oxford University Hospitals National Health Service Foundation Trust, Oxford OX3 9DU, UK
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
| | - Amandeep S. Josan
- Oxford Eye Hospital, Oxford University Hospitals National Health Service Foundation Trust, Oxford OX3 9DU, UK
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
| | - M. Dominik Fischer
- Oxford Eye Hospital, Oxford University Hospitals National Health Service Foundation Trust, Oxford OX3 9DU, UK
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
| | - Robert E. MacLaren
- Oxford Eye Hospital, Oxford University Hospitals National Health Service Foundation Trust, Oxford OX3 9DU, UK
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
| |
Collapse
|
6
|
Aaron KA, Pekrun K, Atkinson PJ, Billings SE, Abitbol JM, Lee IA, Eltawil Y, Chen YS, Dong W, Nelson RF, Kay MA, Cheng AG. Selection of viral capsids and promoters affects the efficacy of rescue of Tmprss3-deficient cochlea. Mol Ther Methods Clin Dev 2023; 30:413-428. [PMID: 37663645 PMCID: PMC10471831 DOI: 10.1016/j.omtm.2023.08.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 08/08/2023] [Indexed: 09/05/2023]
Abstract
Adeno-associated virus (AAV)-mediated gene transfer has shown promise in rescuing mouse models of genetic hearing loss, but how viral capsid and promoter selection affects efficacy is poorly characterized. Here, we tested combinations of AAVs and promoters to deliver Tmprss3, mutations in which are associated with hearing loss in humans. Tmprss3tm1/tm1 mice display severe cochlear hair cell degeneration, loss of auditory brainstem responses, and delayed loss of spiral ganglion neurons. Under the ubiquitous CAG promoter and AAV-KP1 capsid, Tmprss3 overexpression caused striking cytotoxicity in vitro and in vivo and failed to rescue degeneration or dysfunction of the Tmprss3tm1/tm1 cochlea. Reducing the dosage or using AAV-DJ-CAG-Tmprss3 diminished cytotoxicity without rescue of the Tmprss3tm1/tm1 cochlea. Finally, the combination of AAV-KP1 capsid and the EF1α promoter prevented cytotoxicity and reduced hair cell degeneration, loss of spiral ganglion neurons, and improved hearing thresholds in Tmprss3tm1/tm1 mice. Together, our study illustrates toxicity of exogenous genes and factors governing rescue efficiency, and suggests that cochlear gene therapy likely requires precisely targeted transgene expression.
Collapse
Affiliation(s)
- Ksenia A. Aaron
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
- Head and Neck Institute, Cleveland Clinic Foundation, Cleveland, OH 44195, USA
| | - Katja Pekrun
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA 94305, USA
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Patrick J. Atkinson
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Sara E. Billings
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Julia M. Abitbol
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Ina A. Lee
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Yasmin Eltawil
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Yuan-Siao Chen
- Department of Otolaryngology-Head and Neck Surgery, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Wuxing Dong
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Rick F. Nelson
- Department of Otolaryngology-Head and Neck Surgery, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Mark A. Kay
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA 94305, USA
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Alan G. Cheng
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA 94305, USA
| |
Collapse
|
7
|
Shamshad A, Kang C, Jenny LA, Persad-Paisley EM, Tsang SH. Translatability barriers between preclinical and clinical trials of AAV gene therapy in inherited retinal diseases. Vision Res 2023; 210:108258. [PMID: 37244011 PMCID: PMC10526971 DOI: 10.1016/j.visres.2023.108258] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 05/02/2023] [Accepted: 05/09/2023] [Indexed: 05/29/2023]
Abstract
Inherited retinal diseases (IRDs) are progressive degenerative diseases which cause gradual vision loss or complete blindness. As over 270 gene mutations have been identified in the underlying pathology of IRDs, gene therapy as a treatment modality has been an increasingly active realm of investigation. Currently, the most common vehicle of ocular gene delivery is the adeno-associated virus (AAV) vector. This is injected into the immune-privileged subretinal space to mediate transgene expression in retinal cells. Although numerous animal models of IRDs have demonstrated successful outcomes following AAV-mediated gene delivery, many of these studies fail to translate into successful outcomes in clinical trials. The purpose of this review is to A) comparatively assess preclinical and clinical IRD trials in which the success of AAV-mediated therapy failed to translate between animal and human participants B) discuss factors which may complicate the translatability of gene therapy in animals to results in humans.
Collapse
Affiliation(s)
| | - Chaerim Kang
- Warren Alpert Medical School of Brown University, USA
| | - Laura A Jenny
- Edward S. Harkness Eye Institute, Department of Ophthalmology, Columbia University Irving Medical Center/New York-Presbyterian Hospital, New York, NY, USA; Jonas Children's Vision Care, and Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University, New York, NY, USA
| | | | - Stephen H Tsang
- Edward S. Harkness Eye Institute, Department of Ophthalmology, Columbia University Irving Medical Center/New York-Presbyterian Hospital, New York, NY, USA; Jonas Children's Vision Care, and Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University, New York, NY, USA; Department of Pathology and Cell Biology, Columbia University, New York, NY, USA; Department of Biomedical Engineering, Columbia University, New York, NY, USA; Columbia Stem Cell Initiative, Columbia University, New York, NY, USA; Insitute of Human Nutrition, Columbia University, New York, NY, USA
| |
Collapse
|
8
|
Ding WY, Kuzmuk V, Hunter S, Lay A, Hayes B, Beesley M, Rollason R, Hurcombe JA, Barrington F, Masson C, Cathery W, May C, Tuffin J, Roberts T, Mollet G, Chu CJ, McIntosh J, Coward RJ, Antignac C, Nathwani A, Welsh GI, Saleem MA. Adeno-associated virus gene therapy prevents progression of kidney disease in genetic models of nephrotic syndrome. Sci Transl Med 2023; 15:eabc8226. [PMID: 37556557 DOI: 10.1126/scitranslmed.abc8226] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 07/21/2023] [Indexed: 08/11/2023]
Abstract
Gene therapy for kidney diseases has proven challenging. Adeno-associated virus (AAV) is used as a vector for gene therapy targeting other organs, with particular success demonstrated in monogenic diseases. We aimed to establish gene therapy for the kidney by targeting a monogenic disease of the kidney podocyte. The most common cause of childhood genetic nephrotic syndrome is mutations in the podocyte gene NPHS2, encoding podocin. We used AAV-based gene therapy to rescue this genetic defect in human and mouse models of disease. In vitro transduction studies identified the AAV-LK03 serotype as a highly efficient transducer of human podocytes. AAV-LK03-mediated transduction of podocin in mutant human podocytes resulted in functional rescue in vitro, and AAV 2/9-mediated gene transfer in both the inducible podocin knockout and knock-in mouse models resulted in successful amelioration of kidney disease. A prophylactic approach of AAV 2/9 gene transfer before induction of disease in conditional knockout mice demonstrated improvements in albuminuria, plasma creatinine, plasma urea, plasma cholesterol, histological changes, and long-term survival. A therapeutic approach of AAV 2/9 gene transfer 2 weeks after disease induction in proteinuric conditional knock-in mice demonstrated improvement in urinary albuminuria at days 42 and 56 after disease induction, with corresponding improvements in plasma albumin. Therefore, we have demonstrated successful AAV-mediated gene rescue in a monogenic renal disease and established the podocyte as a tractable target for gene therapy approaches.
Collapse
Affiliation(s)
- Wen Y Ding
- Bristol Renal, Bristol Medical School, Dorothy Hodgkin Building, University of Bristol, Bristol BS1 3NY, UK
| | - Valeryia Kuzmuk
- Bristol Renal, Bristol Medical School, Dorothy Hodgkin Building, University of Bristol, Bristol BS1 3NY, UK
- Purespring Therapeutics, Rolling Stock Yard, 188 York Way, London N7 9AS, UK
| | - Sarah Hunter
- Bristol Renal, Bristol Medical School, Dorothy Hodgkin Building, University of Bristol, Bristol BS1 3NY, UK
| | - Abigail Lay
- Bristol Renal, Bristol Medical School, Dorothy Hodgkin Building, University of Bristol, Bristol BS1 3NY, UK
| | - Bryony Hayes
- Bristol Renal, Bristol Medical School, Dorothy Hodgkin Building, University of Bristol, Bristol BS1 3NY, UK
| | - Matthew Beesley
- Department of Histopathology, Cheltenham General Hospital, Cheltenham GL53 7AN, UK
| | - Ruth Rollason
- Bristol Renal, Bristol Medical School, Dorothy Hodgkin Building, University of Bristol, Bristol BS1 3NY, UK
| | - Jennifer A Hurcombe
- Bristol Renal, Bristol Medical School, Dorothy Hodgkin Building, University of Bristol, Bristol BS1 3NY, UK
| | - Fern Barrington
- Bristol Renal, Bristol Medical School, Dorothy Hodgkin Building, University of Bristol, Bristol BS1 3NY, UK
| | - Catrin Masson
- Bristol Renal, Bristol Medical School, Dorothy Hodgkin Building, University of Bristol, Bristol BS1 3NY, UK
| | - William Cathery
- Bristol Renal, Bristol Medical School, Dorothy Hodgkin Building, University of Bristol, Bristol BS1 3NY, UK
| | - Carl May
- Bristol Renal, Bristol Medical School, Dorothy Hodgkin Building, University of Bristol, Bristol BS1 3NY, UK
| | - Jack Tuffin
- Purespring Therapeutics, Rolling Stock Yard, 188 York Way, London N7 9AS, UK
| | - Timothy Roberts
- Bristol Renal, Bristol Medical School, Dorothy Hodgkin Building, University of Bristol, Bristol BS1 3NY, UK
| | - Geraldine Mollet
- Laboratoire des Maladies Rénales Héréditaires, Inserm UMR 1163, Institut Imagine, Université Paris Cité, Paris 75015, France
| | - Colin J Chu
- Academic Unit of Ophthalmology, Bristol Medical School, Biomedical Sciences Building, University of Bristol, Bristol BS8 1TD, UK
| | - Jenny McIntosh
- Research Department of Haematology, UCL Cancer Institute, Paul O'Gorman Building, University College London, London WC1E 6BT, UK
| | - Richard J Coward
- Bristol Renal, Bristol Medical School, Dorothy Hodgkin Building, University of Bristol, Bristol BS1 3NY, UK
| | - Corinne Antignac
- Laboratoire des Maladies Rénales Héréditaires, Inserm UMR 1163, Institut Imagine, Université Paris Cité, Paris 75015, France
| | - Amit Nathwani
- Research Department of Haematology, UCL Cancer Institute, Paul O'Gorman Building, University College London, London WC1E 6BT, UK
| | - Gavin I Welsh
- Bristol Renal, Bristol Medical School, Dorothy Hodgkin Building, University of Bristol, Bristol BS1 3NY, UK
| | - Moin A Saleem
- Bristol Renal, Bristol Medical School, Dorothy Hodgkin Building, University of Bristol, Bristol BS1 3NY, UK
| |
Collapse
|
9
|
Seo JJ, Jung SJ, Yang J, Choi DE, Kim VN. Functional viromic screens uncover regulatory RNA elements. Cell 2023:S0092-8674(23)00675-X. [PMID: 37413987 DOI: 10.1016/j.cell.2023.06.007] [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: 11/12/2022] [Revised: 04/21/2023] [Accepted: 06/10/2023] [Indexed: 07/08/2023]
Abstract
The number of sequenced viral genomes has surged recently, presenting an opportunity to understand viral diversity and uncover unknown regulatory mechanisms. Here, we conducted a screening of 30,367 viral segments from 143 species representing 96 genera and 37 families. Using a library of viral segments in 3' UTR, we identified hundreds of elements impacting RNA abundance, translation, and nucleocytoplasmic distribution. To illustrate the power of this approach, we investigated K5, an element conserved in kobuviruses, and found its potent ability to enhance mRNA stability and translation in various contexts, including adeno-associated viral vectors and synthetic mRNAs. Moreover, we identified a previously uncharacterized protein, ZCCHC2, as a critical host factor for K5. ZCCHC2 recruits the terminal nucleotidyl transferase TENT4 to elongate poly(A) tails with mixed sequences, delaying deadenylation. This study provides a unique resource for virus and RNA research and highlights the potential of the virosphere for biological discoveries.
Collapse
Affiliation(s)
- Jenny J Seo
- Center for RNA Research, Institute for Basic Science, Seoul 08826, Republic of Korea; School of Biological Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Soo-Jin Jung
- Center for RNA Research, Institute for Basic Science, Seoul 08826, Republic of Korea; School of Biological Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Jihye Yang
- Center for RNA Research, Institute for Basic Science, Seoul 08826, Republic of Korea; School of Biological Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Da-Eun Choi
- Center for RNA Research, Institute for Basic Science, Seoul 08826, Republic of Korea; School of Biological Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - V Narry Kim
- Center for RNA Research, Institute for Basic Science, Seoul 08826, Republic of Korea; School of Biological Sciences, Seoul National University, Seoul 08826, Republic of Korea.
| |
Collapse
|
10
|
Nieuwenhuis B, Laperrousaz E, Tribble JR, Verhaagen J, Fawcett JW, Martin KR, Williams PA, Osborne A. Improving adeno-associated viral (AAV) vector-mediated transgene expression in retinal ganglion cells: comparison of five promoters. Gene Ther 2023:10.1038/s41434-022-00380-z. [PMID: 36635457 DOI: 10.1038/s41434-022-00380-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 12/02/2022] [Accepted: 12/21/2022] [Indexed: 01/14/2023]
Abstract
Recombinant adeno-associated viral vectors (AAVs) are an effective system for gene transfer. AAV serotype 2 (AAV2) is commonly used to deliver transgenes to retinal ganglion cells (RGCs) via intravitreal injection. The AAV serotype however is not the only factor contributing to the effectiveness of gene therapies. Promoters influence the strength and cell-selectivity of transgene expression. This study compares five promoters designed to maximise AAV2 cargo space for gene delivery: chicken β-actin (CBA), cytomegalovirus (CMV), short CMV early enhancer/chicken β-actin/short β-globulin intron (sCAG), mouse phosphoglycerate kinase (PGK), and human synapsin (SYN). The promoters driving enhanced green fluorescent protein (eGFP) were examined in adult C57BL/6J mice eyes and tissues of the visual system. eGFP expression was strongest in the retina, optic nerves and brain when driven by the sCAG and SYN promoters. CBA, CMV, and PGK had moderate expression by comparison. The SYN promoter had almost exclusive transgene expression in RGCs. The PGK promoter had predominant expression in both RGCs and AII amacrine cells. The ubiquitous CBA, CMV, and sCAG promoters expressed eGFP in a variety of cell types across multiple retinal layers including Müller glia and astrocytes. We also found that these promoters could transduce human retina ex vivo, although expression was predominantly in glial cells due to low RGC viability. Taken together, this promoter comparison study contributes to optimising AAV-mediated transduction in the retina, and could be valuable for research in ocular disorders, particularly those with large or complex genetic cargos.
Collapse
Affiliation(s)
- Bart Nieuwenhuis
- John van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK. .,Cambridge Institute for Medical Research, University of Cambridge, Cambridge, CB2 0XY, UK.
| | - Elise Laperrousaz
- John van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - James R Tribble
- Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden
| | - Joost Verhaagen
- Laboratory for Regeneration of Sensorimotor Systems, Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences (KNAW), Amsterdam, The Netherlands.,Centre for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - James W Fawcett
- John van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK.,Centre of Reconstructive Neuroscience, Institute of Experimental Medicine, Prague, Czech Republic
| | - Keith R Martin
- John van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK.,Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, VIC, Australia.,Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, VIC, Australia
| | - Pete A Williams
- Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden
| | - Andrew Osborne
- John van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK. .,Ikarovec Ltd, The Norwich Research Park Innovation Centre, Norwich, UK.
| |
Collapse
|
11
|
Nieuwenhuis B, Osborne A. Intravitreal Injection of AAV for the Transduction of Mouse Retinal Ganglion Cells. Methods Mol Biol 2023; 2708:155-174. [PMID: 37558970 DOI: 10.1007/978-1-0716-3409-7_17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/11/2023]
Abstract
The injection of therapies into the eye is common practice, both clinically and pre-clinically. The most straightforward delivery route is via an intravitreal injection, which introduces the treatment into the largest cavity at the posterior of the eye. This technique is frequently used to deliver gene therapies, including those containing recombinant adeno-associated viral vectors (AAVs), to the back of the eye to enable inner retinal targeting. This chapter provides detailed methodology on how to successfully perform an intravitreal injection in mice. The chapter covers vector preparation considerations, advice on how to minimize vector loss in the injection device, and ways to reduce vector reflux from the eye when administering a therapy. Finally, a protocol is provided on common retinal histology processing techniques to assess vector-mediated expression in retinal ganglion cells. It is hoped that this chapter will enable researchers to carry out effective and consistent intravitreal injections that transduce the inner retinal surface while avoiding common pitfalls.
Collapse
Affiliation(s)
- Bart Nieuwenhuis
- John van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK
| | - Andrew Osborne
- John van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK.
- Ikarovec Ltd, The Norwich Research Park Innovation Centre, Norwich, UK.
| |
Collapse
|
12
|
Sun C, Chen S. Gene Augmentation for Autosomal Dominant CRX-Associated Retinopathies. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1415:135-141. [PMID: 37440026 PMCID: PMC11010719 DOI: 10.1007/978-3-031-27681-1_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/14/2023]
Abstract
The cone-rod homeobox (CRX) protein is a key transcription factor essential for photoreceptor function and survival. Mutations in human CRX gene are linked to a wide spectrum of blinding diseases ranging from mild macular dystrophy to severe Leber congenital amaurosis (LCA), cone-rod dystrophy (CRD), and retinitis pigmentosa (RP). These diseases are still incurable and mostly inherited in an autosomal dominant form. Dysfunctional mutant CRX protein interferes with the function of wild-type CRX protein, demonstrating the dominant negative effect. At present, gene augmentation is the most promising treatment strategy for hereditary diseases. This study aims to review the pathogenic mechanisms of various CRX mutations and propose two therapeutic strategies to rescue sick photoreceptors in CRX-associated retinopathies, namely, Tet-On-hCRX system and adeno-associated virus (AAV)-mediated gene augmentation. The outcome of proposed studies will guide future translational research and suggest guidelines for therapy evaluation in terms of treatment safety and efficacy.
Collapse
Affiliation(s)
- Chi Sun
- Department of Ophthalmology and Visual Sciences, Washington University, St. Louis, MO, USA.
| | - Shiming Chen
- Department of Ophthalmology and Visual Sciences, Washington University, St. Louis, MO, USA
- Department of Developmental Biology, Washington University, St. Louis, MO, USA
| |
Collapse
|
13
|
Develop an efficient and specific AAV-based labeling system for Muller glia in mice. Sci Rep 2022; 12:22410. [PMID: 36575359 PMCID: PMC9794687 DOI: 10.1038/s41598-022-27013-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Accepted: 12/23/2022] [Indexed: 12/28/2022] Open
Abstract
Reprogramming Müller glia (MG) into functional cells is considered a promising therapeutic strategy to treat ocular diseases and vision loss. However, current AAV-based system for MG-tracing was reported to have high leakage in recent studies. Here, we focused on reducing the leakage of AAV-based labeling systems and found that different AAV serotypes showed a range of efficiency and specificity in labeling MG, leading us to optimize a human GFAP-Cre reporter system packaged in the AAV9 serotype with the woodchuck hepatitis virus post-transcriptional regulatory element (WPRE) removed. The leakage ratio of the AAV9-hGFAP-Cre-ΔWPRE decreased by an approximate 40-fold compared with the AAV9-hGFAP-Cre-WPRE labeling system. In addition, we validated the specificity of the AAV-ΔWPRE system for tracing MG reprogramming under Ptbp1-suppression and observed strict non-MG-conversion, similar to previous studies using genetic lineage tracking mouse models. Thus, the AAV9-hGFAP-Cre-ΔWPRE system showed high efficiency and specificity for MG labeling, providing a promising tool for tracing cell fate in vivo.
Collapse
|
14
|
Wu WH, Tso A, Breazzano MP, Jenny LA, Levi SR, Tsang SH, Quinn PMJ. Culture of Human Retinal Explants for Ex Vivo Assessment of AAV Gene Delivery. Methods Mol Biol 2022; 2560:303-311. [PMID: 36481906 DOI: 10.1007/978-1-0716-2651-1_28] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Due to the clinically established safety and efficacy profile of recombinant adeno-associated viral (rAAV) vectors, they are considered the "go to" vector for retinal gene therapy. Design of a rAAV-mediated gene therapy focuses on cell tropism, high transduction efficiency, and high transgene expression levels to achieve the lowest therapeutic treatment dosage and avoid toxicity. Human retinal explants are a clinically relevant model system for exploring these aspects of rAAV-mediated gene delivery. In this chapter, we describe an ex vivo human retinal explant culture protocol to evaluate transgene expression in order to determine the selectivity and efficacy of rAAV vectors for human retinal gene therapy.
Collapse
Affiliation(s)
- Wen-Hsuan Wu
- Edward S. Harkness Eye Institute, Department of Ophthalmology, Columbia University Irving Medical Center/New York-Presbyterian Hospital, New York, NY, USA
| | - Amy Tso
- Edward S. Harkness Eye Institute, Department of Ophthalmology, Columbia University Irving Medical Center/New York-Presbyterian Hospital, New York, NY, USA
| | - Mark P Breazzano
- Edward S. Harkness Eye Institute, Department of Ophthalmology, Columbia University Irving Medical Center/New York-Presbyterian Hospital, New York, NY, USA.,Department of Ophthalmology, New York University School of Medicine, New York University Langone Health, New York, NY, USA.,Manhattan Eye, Ear and Throat Hospital, Lenox Hill Hospital, Northwell Health, New York, NY, USA
| | - Laura A Jenny
- Edward S. Harkness Eye Institute, Department of Ophthalmology, Columbia University Irving Medical Center/New York-Presbyterian Hospital, New York, NY, USA.,Department of Ophthalmology, New York University School of Medicine, New York University Langone Health, New York, NY, USA.,Manhattan Eye, Ear and Throat Hospital, Lenox Hill Hospital, Northwell Health, New York, NY, USA
| | - Sarah R Levi
- Edward S. Harkness Eye Institute, Department of Ophthalmology, Columbia University Irving Medical Center/New York-Presbyterian Hospital, New York, NY, USA.,Department of Ophthalmology, New York University School of Medicine, New York University Langone Health, New York, NY, USA.,Manhattan Eye, Ear and Throat Hospital, Lenox Hill Hospital, Northwell Health, New York, NY, USA
| | - Stephen H Tsang
- Departments of Ophthalmology, Pathology & Cell Biology, Graduate Programs in Nutritional & Metabolic Biology and Neurobiology & Behavior, Columbia Stem Cell Initiative, New York, NY, USA
| | - Peter M J Quinn
- Department of Opthalmology, Columbia University Medical Center, New York, NY, USA.
| |
Collapse
|
15
|
Pupo A, Fernández A, Low SH, François A, Suárez-Amarán L, Samulski RJ. AAV vectors: The Rubik's cube of human gene therapy. Mol Ther 2022; 30:3515-3541. [PMID: 36203359 PMCID: PMC9734031 DOI: 10.1016/j.ymthe.2022.09.015] [Citation(s) in RCA: 100] [Impact Index Per Article: 50.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 09/21/2022] [Accepted: 09/23/2022] [Indexed: 12/12/2022] Open
Abstract
Defective genes account for ∼80% of the total of more than 7,000 diseases known to date. Gene therapy brings the promise of a one-time treatment option that will fix the errors in patient genetic coding. Recombinant viruses are highly efficient vehicles for in vivo gene delivery. Adeno-associated virus (AAV) vectors offer unique advantages, such as tissue tropism, specificity in transduction, eliciting of a relatively low immune responses, no incorporation into the host chromosome, and long-lasting delivered gene expression, making them the most popular viral gene delivery system in clinical trials, with three AAV-based gene therapy drugs already approved by the US Food and Drug Administration (FDA) or European Medicines Agency (EMA). Despite the success of AAV vectors, their usage in particular scenarios is still limited due to remaining challenges, such as poor transduction efficiency in certain tissues, low organ specificity, pre-existing humoral immunity to AAV capsids, and vector dose-dependent toxicity in patients. In the present review, we address the different approaches to improve AAV vectors for gene therapy with a focus on AAV capsid selection and engineering, strategies to overcome anti-AAV immune response, and vector genome design, ending with a glimpse at vector production methods and the current state of recombinant AAV (rAAV) at the clinical level.
Collapse
Affiliation(s)
- Amaury Pupo
- R&D Department, Asklepios BioPharmaceutical, Inc. (AskBio), 20 T.W. Alexander, Suite 110 RTP, Durham, NC 27709, USA
| | - Audry Fernández
- R&D Department, Asklepios BioPharmaceutical, Inc. (AskBio), 20 T.W. Alexander, Suite 110 RTP, Durham, NC 27709, USA
| | - Siew Hui Low
- R&D Department, Asklepios BioPharmaceutical, Inc. (AskBio), 20 T.W. Alexander, Suite 110 RTP, Durham, NC 27709, USA
| | - Achille François
- Viralgen. Parque Tecnológico de Guipuzkoa, Edificio Kuatro, Paseo Mikeletegui, 83, 20009 San Sebastián, Spain
| | - Lester Suárez-Amarán
- R&D Department, Asklepios BioPharmaceutical, Inc. (AskBio), 20 T.W. Alexander, Suite 110 RTP, Durham, NC 27709, USA
| | - Richard Jude Samulski
- R&D Department, Asklepios BioPharmaceutical, Inc. (AskBio), 20 T.W. Alexander, Suite 110 RTP, Durham, NC 27709, USA,Department of Pharmacology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA,Corresponding author: Richard Jude Samulski, R&D Department, Asklepios BioPharmaceutical, Inc. (AskBio), 20 T.W. Alexander, Suite 110 RTP, NC 27709, USA.
| |
Collapse
|
16
|
Optogenetic restoration of high sensitivity vision with bReaChES, a red-shifted channelrhodopsin. Sci Rep 2022; 12:19312. [PMID: 36369267 PMCID: PMC9652428 DOI: 10.1038/s41598-022-23572-4] [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: 09/01/2022] [Accepted: 11/02/2022] [Indexed: 11/13/2022] Open
Abstract
The common final pathway to blindness in many forms of retinal degeneration is the death of the light-sensitive primary retinal neurons. However, the normally light-insensitive second- and third-order neurons persist optogenetic gene therapy aims to restore sight by rendering such neurons light-sensitive. Here, we investigate whether bReaChES, a newly described high sensitivity Type I opsin with peak sensitivity to long-wavelength visible light, can restore vision in a murine model of severe early-onset retinal degeneration. Intravitreal injection of an adeno-associated viral vector carrying the sequence for bReaChES downstream of the calcium calmodulin kinase IIα promoter resulted in sustained retinal expression of bReaChES. Retinal ganglion cells (RGCs) expressing bReaChES generated action potentials at light levels consistent with bright indoor lighting (from 13.6 log photons cm-2 s-1). They could also detect flicker at up to 50 Hz, which approaches the upper temporal limit of human photopic vision. Topological response maps of bReaChES-expressing RGCs suggest that optogenetically activated RGCs may demonstrate similar topographical responses to RGCs stimulated by photoreceptor activation. Furthermore, treated dystrophic mice displayed restored cortical neuronal activity in response to light and rescued behavioral responses to a looming stimulus that simulated an aerial predator. Finally, human surgical retinal explants exposed to the bReaChES treatment vector demonstrated transduction. Together, these findings suggest that intravitreal gene therapy to deliver bReaChES to the retina may restore vision in human retinal degeneration in vivo at ecologically relevant light levels with spectral and temporal response characteristics approaching those of normal human photopic vision.
Collapse
|
17
|
Staurenghi F, McClements ME, Salman A, MacLaren RE. Minicircle Delivery to the Neural Retina as a Gene Therapy Approach. Int J Mol Sci 2022; 23:11673. [PMID: 36232975 PMCID: PMC9569440 DOI: 10.3390/ijms231911673] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 09/26/2022] [Accepted: 09/28/2022] [Indexed: 11/07/2022] Open
Abstract
Non-viral gene therapy has the potential to overcome several shortcomings in viral vector-based therapeutics. Methods of in vivo plasmid delivery have developed over recent years to increase the efficiency of non-viral gene transfer, yet further improvements still need to be made to improve their translational capacity. Gene therapy advances for inherited retinal disease have been particularly prominent over the recent decade but overcoming physical and physiological barriers present in the eye remains a key obstacle in the field of non-viral ocular drug delivery. Minicircles are circular double-stranded DNA vectors that contain expression cassettes devoid of bacterial DNA, thereby limiting the risks of innate immune responses induced by such elements. To date, they have not been extensively used in pre-clinical studies yet remain a viable vector option for the treatment of inherited retinal disease. Here, we explore the potential of minicircle DNA delivery to the neural retina as a gene therapy approach. We consider the advantages of minicircles as gene therapy vectors as well as review the challenges involved in optimising their delivery to the neural retina.
Collapse
Affiliation(s)
- Federica Staurenghi
- Nuffield Laboratory of Ophthalmology, Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
| | - Michelle E. McClements
- Nuffield Laboratory of Ophthalmology, Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
| | - Ahmed Salman
- Nuffield Laboratory of Ophthalmology, Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
| | - Robert E. MacLaren
- Nuffield Laboratory of Ophthalmology, Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
- Oxford University Hospital, Oxford OX3 9DU, UK
| |
Collapse
|
18
|
Abstract
In 2001, the first large animal was successfully treated with a gene therapy that restored its vision. Lancelot, the Briard dog that was treated, suffered from a human childhood blindness called Leber's congenital amaurosis type 2. Sixteen years later, the gene therapy was approved by the U.S. Food and Drug Administration. The success of this gene therapy in dogs led to a fast expansion of the ocular gene therapy field. By now every class of inherited retinal dystrophy has been treated in at least one animal model and many clinical trials have been initiated in humans. In this study, we review the status of viral gene therapies for the retina, with a focus on ongoing human clinical trials. It is likely that in the next decade we will see several new viral gene therapies approved.
Collapse
Affiliation(s)
- Shun-Yun Cheng
- University of Massachusetts Medical School, Ophthalmology, Worcester, Massachusetts, United States;
| | - Claudio Punzo
- University of Massachusetts Medical School, Ophthalmology, 368 Plantation Street, Albert Sherman Center, AS6-2041, Worcester, Massachusetts, United States, 01605;
| |
Collapse
|
19
|
Xi Z, Öztürk BE, Johnson ME, Turunç S, Stauffer WR, Byrne LC. Quantitative single-cell transcriptome-based ranking of engineered AAVs in human retinal explants. Mol Ther Methods Clin Dev 2022; 25:476-489. [PMID: 35615708 PMCID: PMC9118357 DOI: 10.1016/j.omtm.2022.04.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 04/26/2022] [Indexed: 11/07/2022]
Abstract
Gene therapy is a rapidly developing field, and adeno-associated viruses (AAVs) are a leading viral-vector candidate for therapeutic gene delivery. Newly engineered AAVs with improved abilities are now entering the clinic. It has proven challenging, however, to predict the translational potential of gene therapies developed in animal models due to cross-species differences. Human retinal explants are the only available model of fully developed human retinal tissue and are thus important for the validation of candidate AAV vectors. In this study, we evaluated 18 wild-type and engineered AAV capsids in human retinal explants using a recently developed single-cell RNA sequencing (RNA-seq) AAV engineering pipeline (scAAVengr). Human retinal explants retained the same major cell types as fresh retina, with similar expression of cell-specific markers except for a photoreceptor population with altered expression of photoreceptor-specific genes. The efficiency and tropism of AAVs in human explants were quantified with single-cell resolution. The top-performing serotypes, K91, K912, and 7m8, were further validated in non-human primate and human retinal explants. Together, this study provides detailed information about the transcriptome profiles of retinal explants and quantifies the infectivity of leading AAV serotypes in human retina, accelerating the translation of retinal gene therapies to the clinic.
Collapse
Affiliation(s)
- Zhouhuan Xi
- Department of Ophthalmology, University of Pittsburgh, PA, USA.,Eye Center of Xiangya Hospital, Hunan Key Laboratory of Ophthalmology, Central South University, Changsha, Hunan, China
| | - Bilge E Öztürk
- Department of Ophthalmology, University of Pittsburgh, PA, USA
| | - Molly E Johnson
- Department of Ophthalmology, University of Pittsburgh, PA, USA
| | - Serhan Turunç
- Department of Ophthalmology, University of Pittsburgh, PA, USA
| | | | - Leah C Byrne
- Department of Ophthalmology, University of Pittsburgh, PA, USA.,Department of Neurobiology, University of Pittsburgh, PA, USA.,Department of Bioengineering, University of Pittsburgh, PA, USA
| |
Collapse
|
20
|
Marino M, Holt MG. AAV Vector-Mediated Antibody Delivery (A-MAD) in the Central Nervous System. Front Neurol 2022; 13:870799. [PMID: 35493843 PMCID: PMC9039256 DOI: 10.3389/fneur.2022.870799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 02/21/2022] [Indexed: 11/13/2022] Open
Abstract
In the last four decades, monoclonal antibodies and their derivatives have emerged as a powerful class of therapeutics, largely due to their exquisite targeting specificity. Several clinical areas, most notably oncology and autoimmune disorders, have seen the successful introduction of monoclonal-based therapeutics. However, their adoption for treatment of Central Nervous System diseases has been comparatively slow, largely due to issues of efficient delivery resulting from limited permeability of the Blood Brain Barrier. Nevertheless, CNS diseases are becoming increasingly prevalent as societies age, accounting for ~6.5 million fatalities worldwide per year. Therefore, harnessing the full therapeutic potential of monoclonal antibodies (and their derivatives) in this clinical area has become a priority. Adeno-associated virus-based vectors (AAVs) are a potential solution to this problem. Preclinical studies have shown that AAV vector-mediated antibody delivery provides protection against a broad range of peripheral diseases, such as the human immunodeficiency virus (HIV), influenza and malaria. The parallel identification and optimization of AAV vector platforms which cross the Blood Brain Barrier with high efficiency, widely transducing the Central Nervous System and allowing high levels of local transgene production, has now opened a number of interesting scenarios for the development of AAV vector-mediated antibody delivery strategies to target Central Nervous System proteinopathies.
Collapse
Affiliation(s)
- Marika Marino
- Laboratory of Glia Biology, VIB-KU Leuven, Center for Brain & Disease Research, Leuven, Belgium
- Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Matthew G. Holt
- Laboratory of Glia Biology, VIB-KU Leuven, Center for Brain & Disease Research, Leuven, Belgium
- Department of Neurosciences, KU Leuven, Leuven, Belgium
- Leuven Brain Institute, Leuven, Belgium
- Synapse Biology Group, Instituto de Investigação e Inovação em Saúde (i3S), University of Porto, Porto, Portugal
- *Correspondence: Matthew G. Holt
| |
Collapse
|
21
|
Duan Y, Ye T, Qu Z, Chen Y, Miranda A, Zhou X, Lok KC, Chen Y, Fu AKY, Gradinaru V, Ip NY. Brain-wide Cas9-mediated cleavage of a gene causing familial Alzheimer's disease alleviates amyloid-related pathologies in mice. Nat Biomed Eng 2022; 6:168-180. [PMID: 34312508 DOI: 10.1038/s41551-021-00759-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 06/08/2021] [Indexed: 02/07/2023]
Abstract
The pathology of familial Alzheimer's disease, which is caused by dominant mutations in the gene that encodes amyloid-beta precursor protein (APP) and in those that encode presenilin 1 and presenilin 2, is characterized by extracellular amyloid plaques and intracellular neurofibrillary tangles in multiple brain regions. Here we show that the brain-wide selective disruption of a mutated APP allele in transgenic mouse models carrying the human APP Swedish mutation alleviates amyloid-beta-associated pathologies for at least six months after a single intrahippocampal administration of an adeno-associated virus that encodes both Cas9 and a single-guide RNA that targets the mutation. We also show that the deposition of amyloid-beta, as well as microgliosis, neurite dystrophy and the impairment of cognitive performance, can all be ameliorated when the CRISPR-Cas9 construct is delivered intravenously via a modified adeno-associated virus that can cross the blood-brain barrier. Brain-wide disease-modifying genome editing could represent a viable strategy for the treatment of familial Alzheimer's disease and other monogenic diseases that affect multiple brain regions.
Collapse
Affiliation(s)
- Yangyang Duan
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Molecular Neuroscience Center, Center for Stem Cell Research, The Hong Kong University of Science and Technology, Hong Kong, China.,Hong Kong Center for Neurodegenerative Diseases, Hong Kong, China
| | - Tao Ye
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Molecular Neuroscience Center, Center for Stem Cell Research, The Hong Kong University of Science and Technology, Hong Kong, China.,Hong Kong Center for Neurodegenerative Diseases, Hong Kong, China.,Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST Shenzhen Research Institute, Shenzhen-Hong Kong Institute of Brain Science, Shenzhen, China.,Chinese Academy of Sciences Key Laboratory of Brain Connectome and Manipulation, Shenzhen Key Laboratory of Translational Research for Brain Diseases, The Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China
| | - Zhe Qu
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Yuewen Chen
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Molecular Neuroscience Center, Center for Stem Cell Research, The Hong Kong University of Science and Technology, Hong Kong, China.,Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST Shenzhen Research Institute, Shenzhen-Hong Kong Institute of Brain Science, Shenzhen, China.,Chinese Academy of Sciences Key Laboratory of Brain Connectome and Manipulation, Shenzhen Key Laboratory of Translational Research for Brain Diseases, The Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China
| | - Abigail Miranda
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Molecular Neuroscience Center, Center for Stem Cell Research, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Xiaopu Zhou
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Molecular Neuroscience Center, Center for Stem Cell Research, The Hong Kong University of Science and Technology, Hong Kong, China.,Hong Kong Center for Neurodegenerative Diseases, Hong Kong, China
| | - Ka-Chun Lok
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Molecular Neuroscience Center, Center for Stem Cell Research, The Hong Kong University of Science and Technology, Hong Kong, China.,Hong Kong Center for Neurodegenerative Diseases, Hong Kong, China
| | - Yu Chen
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Molecular Neuroscience Center, Center for Stem Cell Research, The Hong Kong University of Science and Technology, Hong Kong, China.,Hong Kong Center for Neurodegenerative Diseases, Hong Kong, China.,Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST Shenzhen Research Institute, Shenzhen-Hong Kong Institute of Brain Science, Shenzhen, China.,Chinese Academy of Sciences Key Laboratory of Brain Connectome and Manipulation, Shenzhen Key Laboratory of Translational Research for Brain Diseases, The Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China
| | - Amy K Y Fu
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Molecular Neuroscience Center, Center for Stem Cell Research, The Hong Kong University of Science and Technology, Hong Kong, China.,Hong Kong Center for Neurodegenerative Diseases, Hong Kong, China.,Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST Shenzhen Research Institute, Shenzhen-Hong Kong Institute of Brain Science, Shenzhen, China
| | - Viviana Gradinaru
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Nancy Y Ip
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Molecular Neuroscience Center, Center for Stem Cell Research, The Hong Kong University of Science and Technology, Hong Kong, China. .,Hong Kong Center for Neurodegenerative Diseases, Hong Kong, China. .,Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST Shenzhen Research Institute, Shenzhen-Hong Kong Institute of Brain Science, Shenzhen, China.
| |
Collapse
|
22
|
Gross AL, Gray-Edwards HL, Bebout CN, Ta NL, Nielsen K, Brunson BL, Mercado KRL, Osterhoudt DE, Batista AR, Maitland S, Seyfried TN, Sena-Esteves M, Martin DR. Intravenous delivery of adeno-associated viral gene therapy in feline GM1 gangliosidosis. Brain 2021; 145:655-669. [PMID: 34410345 DOI: 10.1093/brain/awab309] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 07/12/2021] [Accepted: 07/28/2021] [Indexed: 11/14/2022] Open
Abstract
GM1 gangliosidosis is a fatal neurodegenerative disease caused by a deficiency of lysosomal β-galactosidase. In its most severe form, GM1 gangliosidosis causes death by 4 years of age, and no effective treatments exist. Previous work has shown that injection of the brain parenchyma with an adeno-associated viral vector provides pronounced therapeutic benefit in a feline GM1 model. To develop a less invasive treatment for the brain and increase systemic biodistribution, intravenous injection of AAV9 was evaluated. AAV9 expressing feline β-galactosidase was intravenously administered at 1.5x1013 vector genomes/kilogram body weight to six GM1 cats at approximately 1 month of age. The animals were divided into two cohorts: 1) a long-term group, which was followed to humane endpoint, and 2) a short-term group, which was analyzed 16-weeks post treatment. Clinical assessments included neurological exams, cerebrospinal fluid and urine biomarkers, and 7-Telsa magnetic resonance imaging and spectroscopy. Postmortem analysis included β-galactosidase and virus distribution, histological analysis, and ganglioside content. Untreated GM1 animals survived 8.0 ± 0.6 months while intravenous treatment increased survival to an average of 3.5 years (n = 2) with substantial improvements in quality of life and neurologic function. Neurological abnormalities, which in untreated animals progress to the inability to stand and debilitating neurological disease by 8 months of age, were mild in all treated animals. Cerebrospinal fluid biomarkers were normalized, indicating decreased central nervous system cell damage in the treated animals. Urinary glycosaminoglycans decreased to normal levels in the long-term cohort. Magnetic resonance imaging and spectroscopy showed partial preservation of the brain in treated animals, which was supported by postmortem histological evaluation. β-galactosidase activity was increased throughout the central nervous system, reaching carrier levels in much of the cerebrum and normal levels in the cerebellum, spinal cord and cerebrospinal fluid. Ganglioside accumulation was significantly reduced by treatment. Peripheral tissues such as heart, skeletal muscle, and sciatic nerve also had normal β-galactosidase activity in treated GM1 cats. GM1 histopathology was largely corrected with treatment. There was no evidence of tumorigenesis or toxicity. Restoration of β-galactosidase activity in the central nervous system and peripheral organs by intravenous gene therapy led to profound increases in lifespan and quality of life in GM1 cats. This data supports the promise of intravenous gene therapy as a safe, effective treatment for GM1 gangliosidosis.
Collapse
Affiliation(s)
- Amanda L Gross
- Scott-Ritchey Research Center, College of Veterinary Medicine, Auburn University, Auburn, AL 36849 USA.,Department of Anatomy, Physiology, and Pharmacology, College of Veterinary Medicine, Auburn University, AL 36849 USA
| | - Heather L Gray-Edwards
- Scott-Ritchey Research Center, College of Veterinary Medicine, Auburn University, Auburn, AL 36849 USA
| | - Cassie N Bebout
- Scott-Ritchey Research Center, College of Veterinary Medicine, Auburn University, Auburn, AL 36849 USA
| | - Nathan L Ta
- Biology Department, Boston College, Chestnut Hill, MA 02467 USA
| | - Kayly Nielsen
- Scott-Ritchey Research Center, College of Veterinary Medicine, Auburn University, Auburn, AL 36849 USA
| | - Brandon L Brunson
- Department of Anatomy, Physiology, and Pharmacology, College of Veterinary Medicine, Auburn University, AL 36849 USA
| | - Kalajan R Lopez Mercado
- Scott-Ritchey Research Center, College of Veterinary Medicine, Auburn University, Auburn, AL 36849 USA
| | - Devin E Osterhoudt
- Scott-Ritchey Research Center, College of Veterinary Medicine, Auburn University, Auburn, AL 36849 USA
| | - Ana Rita Batista
- Department of Neurology, University of Massachusetts Medical School, Worcester MA 01605 USA.,Horae Gene Therapy Center, University of Massachusetts Medical School, Worcester MA 01605 USA
| | - Stacy Maitland
- Department of Neurology, University of Massachusetts Medical School, Worcester MA 01605 USA.,Horae Gene Therapy Center, University of Massachusetts Medical School, Worcester MA 01605 USA
| | | | - Miguel Sena-Esteves
- Department of Neurology, University of Massachusetts Medical School, Worcester MA 01605 USA.,Horae Gene Therapy Center, University of Massachusetts Medical School, Worcester MA 01605 USA
| | - Douglas R Martin
- Scott-Ritchey Research Center, College of Veterinary Medicine, Auburn University, Auburn, AL 36849 USA.,Department of Anatomy, Physiology, and Pharmacology, College of Veterinary Medicine, Auburn University, AL 36849 USA
| |
Collapse
|
23
|
McClements ME, Butt A, Piotter E, Peddle CF, MacLaren RE. An analysis of the Kozak consensus in retinal genes and its relevance to gene therapy. Mol Vis 2021; 27:233-242. [PMID: 34012226 PMCID: PMC8116250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 05/06/2021] [Indexed: 11/24/2022] Open
Abstract
PURPOSE The classic Kozak consensus is a critical genetic element included in gene therapy transgenes to encourage the translation of the therapeutic coding sequence. Despite optimizations of other transgene elements, the Kozak consensus has not yet been considered for potential tissue-specific sequence refinement. We screened the -9 to -1 region relative to the AUG start codon of retina-specific genes to identify whether a Kozak consensus that is different from the classic sequence may be more appropriate for inclusion in gene therapy transgenes that treat inherited retinal disease. METHODS Sequences for 135 genes known to cause nonsyndromic inherited retinal disease were extracted from the NCBI database, and the -9 to -1 nucleotides were compared. This panel was then refined to 75 genes with specific retinal functions, for which the -9 to -1 nucleotides were placed in front of a GFP transcript sequence and RNAfold predictions performed. These were compared with a GFP sequence with the classic Kozak consensus (GCCGCCACC), and sequences from retinal genes with minimum free energy (MFE) predictions greater than the reference sequence were selected to generate an optimized Kozak consensus sequence. The original Kozak consensus and the refined retina Kozak consensus were placed upstream of the Renilla luciferase coding sequence, which were used to transfect retinoblastoma cell lines Y-79 and WERI-RB-1 and HEK 293T/17 cells. RESULTS The nucleotide frequencies of the original panel of genes were determined to be comparable to the classic Kozak consensus. RNAfold analysis of a GFP transcript with the classic Kozak sequence in the 5' untranslated region (UTR) generated an MFE prediction of -503.3 kcal/mol. RNAfold analysis was then performed with a GFP transcript containing each -9 to -1 Kozak sequence of 75 retinal genes. Thirty-eight of the 75 genes provided a greater MFE value than -503.3 kcal/mol and exhibited an absence of stable secondary structures before the AUG codon. The -9 to -1 nucleotide frequencies of these genes identified a Kozak consensus of ACCGAGACC, differing from the classic Kozak consensus at positions -9, -5, and -4. Applying this sequence to the GFP transcript increased the MFE prediction to -500.1 kcal/mol. The newly identified retina Kozak sequence was also applied to Renilla luciferase plus the REP1 and RPGR transcripts used in current clinical trials. In all examples, the predicted transcript MFE score increased when compared with the current transcript sequences containing classic Kozak consensus sequences. In vitro transfections identified a 7%-9% increase in Renilla activity when incorporating the optimized Kozak sequence. CONCLUSIONS The Kozak consensus is a critical element of eukaryotic genes; therefore, it is a required feature of gene therapy transgenes. To date, the classic sequence of GCCRCC (-6 to -1) has typically been incorporated in gene therapy transgenes, but the analysis described here suggests that, for vectors targeting the retina, using a Kozak consensus derived from retinal genes can provide increased expression of the target product.
Collapse
|
24
|
Functional expression of complement factor I following AAV-mediated gene delivery in the retina of mice and human cells. Gene Ther 2021; 28:265-276. [PMID: 33750925 PMCID: PMC8149295 DOI: 10.1038/s41434-021-00239-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 01/05/2021] [Accepted: 02/03/2021] [Indexed: 01/01/2023]
Abstract
Dry age-related macular degeneration (AMD) is characterised by loss of central vision and currently has no approved medical treatment. Dysregulation of the complement system is thought to play an important role in disease pathology and supplementation of Complement Factor I (CFI), a key regulator of the complement system, has the potential to provide a treatment option for AMD. In this study, we demonstrate the generation of AAV constructs carrying the human CFI sequence and expression of CFI in cell lines and in the retina of C57BL/6 J mice. Four codon optimised constructs were compared to the most common human CFI sequence. All constructs expressed CFI protein; however, most codon optimised sequences resulted in significantly reduced CFI secretion compared to the non-optimised CFI sequence. In vivo expression analysis showed that CFI was predominantly expressed in the RPE and photoreceptors. Secreted protein in vitreous humour was demonstrated to be functionally active. The findings presented here have led to the formulation of an AAV-vectored gene therapy product currently being tested in a first-in-human clinical trial in subjects with geographic atrophy secondary to dry AMD (NCT03846193).
Collapse
|
25
|
Abstract
PURPOSE Choroideremia (CHM) is a rare inherited retinal degeneration resulting from mutation of the CHM gene, which results in absence of functional Rab escort protein 1 (REP1). We evaluated retinal gene therapy with an adeno-associated virus vector that used to deliver a functional version of the CHM gene (AAV2-REP1). METHODS THOR (NCT02671539) is a Phase 2, open-label, single-center, randomized study. Six male patients (51-60 years) with CHM received AAV2-REP1, by a single 0.1-mL subretinal injection of 10 genome particles during vitrectomy. Twelve-month data are reported. RESULTS In study eyes, 4 patients experienced minor changes in best-corrected visual acuity (-4 to +1 Early Treatment Diabetic Retinopathy Study [ETDRS] letters); one gained 17 letters and another lost 14 letters. Control eyes had changes of -2 to +4 letters. In 5/6 patients, improvements in mean (95% confidence intervals) retinal sensitivity (2.3 [4.0] dB), peak retinal sensitivity (2.8 [3.5] dB), and gaze fixation area (-36.1 [66.9] deg) were recorded. Changes in anatomical endpoints were similar between study and control eyes. Adverse events were consistent with the surgical procedure. CONCLUSION Gene therapy with AAV2-REP1 can maintain, and in some cases, improve, visual acuity in CHM. Longer term follow-up is required to establish whether these benefits are maintained.
Collapse
|
26
|
Luchicchi A, Pattij T, Viaña JNM, de Kloet S, Marchant N. Tracing goes viral: Viruses that introduce expression of fluorescent proteins in chemically-specific neurons. J Neurosci Methods 2020; 348:109004. [PMID: 33242528 DOI: 10.1016/j.jneumeth.2020.109004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Revised: 11/12/2020] [Accepted: 11/16/2020] [Indexed: 12/26/2022]
Abstract
Over the last century, there has been great progress in understanding how the brain works. In particular, the last two decades have been crucial in gaining more awareness over the complex functioning of neurotransmitter systems. The use of viral vectors in neuroscience has been pivotal for such development. Exploiting the properties of viral particles, modifying them according to the research needs, and making them target chemically-specific neurons, techniques such as optogenetics and chemogenetics have been developed, which could lead to a giant step toward gene therapy for brain disorders. In this review, we aim to provide an overview of some of the most widely used viral techniques in neuroscience. We will discuss advantages and disadvantages of these methods. In particular, attention is dedicated to the pivotal role played by the introduction of adeno-associated virus and the retrograde tracer canine-associated-2 Cre virus in order to achieve optimal visualization, and interrogation, of chemically-specific neuronal populations and their projections.
Collapse
Affiliation(s)
- Antonio Luchicchi
- Department of Anatomy and Neurosciences, Amsterdam UMC, VU University Medical Center, de Boelelaan 1108, 1081HZ, Amsterdam, the Netherlands.
| | - Tommy Pattij
- Department of Anatomy and Neurosciences, Amsterdam UMC, VU University Medical Center, de Boelelaan 1108, 1081HZ, Amsterdam, the Netherlands
| | - John Noel M Viaña
- Center for Neurogenomics and Cognitive Research (CNCR), VU University Amsterdam, de Boelelaan 1085, 1081HZ, Amsterdam, the Netherlands; Australian National Centre for the Public Awareness of Science, ANU College of Science, The Australian National University, Linnaeus Way, Acton, ACT 2601, Australia
| | - Sybren de Kloet
- Center for Neurogenomics and Cognitive Research (CNCR), VU University Amsterdam, de Boelelaan 1085, 1081HZ, Amsterdam, the Netherlands
| | - Nathan Marchant
- Department of Anatomy and Neurosciences, Amsterdam UMC, VU University Medical Center, de Boelelaan 1108, 1081HZ, Amsterdam, the Netherlands
| |
Collapse
|
27
|
McClements ME, Staurenghi F, MacLaren RE, Cehajic-Kapetanovic J. Optogenetic Gene Therapy for the Degenerate Retina: Recent Advances. Front Neurosci 2020; 14:570909. [PMID: 33262683 PMCID: PMC7686539 DOI: 10.3389/fnins.2020.570909] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 10/23/2020] [Indexed: 12/18/2022] Open
Abstract
The degeneration of light-detecting rod and cone photoreceptors in the human retina leads to severe visual impairment and ultimately legal blindness in millions of people worldwide. Multiple therapeutic options at different stages of degeneration are being explored but the majority of ongoing clinical trials involve adeno-associated viral (AAV) vector-based gene supplementation strategies for select forms of inherited retinal disease. Over 300 genes are associated with inherited retinal degenerations and only a small proportion of these will be suitable for gene replacement therapy. However, while the origins of disease may vary, there are considerable similarities in the physiological changes that occur in the retina. When early therapeutic intervention is not possible and patients suffer loss of photoreceptor cells but maintain remaining layers of cells in the neural retina, there is an opportunity for a universal gene therapy approach that can be applied regardless of the genetic origin of disease. Optogenetic therapy offers such a strategy by aiming to restore vision though the provision of light-sensitive molecules to surviving cell types of the retina that enable light perception through the residual neurons. Here we review the recent progress in attempts to restore visual function to the degenerate retina using optogenetic therapy. We focus on multiple pre-clinical models used in optogenetic strategies, discuss their strengths and limitations, and highlight considerations including vector and transgene designs that have advanced the field into two ongoing clinical trials.
Collapse
Affiliation(s)
- Michelle E. McClements
- Nuffield Laboratory Ophthalmology, Department of Clinical Neurosciences, NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, United Kingdom
| | - Federica Staurenghi
- Nuffield Laboratory Ophthalmology, Department of Clinical Neurosciences, NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, United Kingdom
| | - Robert E. MacLaren
- Nuffield Laboratory Ophthalmology, Department of Clinical Neurosciences, NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, United Kingdom
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | - Jasmina Cehajic-Kapetanovic
- Nuffield Laboratory Ophthalmology, Department of Clinical Neurosciences, NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, United Kingdom
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| |
Collapse
|
28
|
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]
|
29
|
Greenwald SH, Brown EE, Scandura MJ, Hennessey E, Farmer R, Pawlyk BS, Xiao R, Vandenberghe LH, Pierce EA. Gene Therapy Preserves Retinal Structure and Function in a Mouse Model of NMNAT1-Associated Retinal Degeneration. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2020; 18:582-594. [PMID: 32775493 PMCID: PMC7397406 DOI: 10.1016/j.omtm.2020.07.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 07/06/2020] [Indexed: 12/17/2022]
Abstract
No treatment is available for nicotinamide mononucleotide adenylyltransferase 1 (NMNAT1)-associated retinal degeneration, an inherited disease that leads to severe vision loss early in life. Although the causative gene, NMNAT1, plays an essential role in nuclear nicotinamide adenine dinucleotide (NAD)+ metabolism in tissues throughout the body, NMNAT1-associated disease is isolated to the retina. Since this condition is recessive, supplementing the retina with a normal copy of NMNAT1 should protect vulnerable cells from disease progression. We tested this hypothesis in a mouse model that harbors the p.Val9Met mutation in Nmnat1 and consequently develops a retinal degenerative phenotype that recapitulates key features of the human disease. Gene augmentation therapy, delivered by subretinal injection of adeno-associated virus (AAV) carrying a normal human copy of NMNAT1, rescued retinal structure and function. Due to the early-onset profile of the phenotype, a rapidly activating self-complementary AAV was required to initiate transgene expression during the narrow therapeutic window. These data represent the first proof of concept for a therapy to treat patients with NMNAT1-associated disease.
Collapse
Affiliation(s)
- Scott H Greenwald
- Ocular Genomics Institute, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA
| | - Emily E Brown
- Ocular Genomics Institute, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA
| | - Michael J Scandura
- Ocular Genomics Institute, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA
| | - Erin Hennessey
- Ocular Genomics Institute, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA
| | - Raymond Farmer
- Ocular Genomics Institute, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA
| | - Basil S Pawlyk
- Ocular Genomics Institute, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA
| | - Ru Xiao
- Ocular Genomics Institute, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA.,Ocular Genomics Institute, Grousebeck Gene Therapy Center, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA
| | - Luk H Vandenberghe
- Ocular Genomics Institute, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA.,Ocular Genomics Institute, Grousebeck Gene Therapy Center, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA
| | - Eric A Pierce
- Ocular Genomics Institute, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA
| |
Collapse
|
30
|
Orlans HO, Barnard AR, Patrício MI, McClements ME, MacLaren RE. Effect of AAV-Mediated Rhodopsin Gene Augmentation on Retinal Degeneration Caused by the Dominant P23H Rhodopsin Mutation in a Knock-In Murine Model. Hum Gene Ther 2020; 31:730-742. [DOI: 10.1089/hum.2020.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Affiliation(s)
- Harry O. Orlans
- Nuffield Laboratory of Ophthalmology, John Radcliffe Hospital, Oxford, United Kingdom
- Moorfields Eye Hospital, London, United Kingdom
| | - Alun R. Barnard
- Nuffield Laboratory of Ophthalmology, John Radcliffe Hospital, Oxford, United Kingdom
| | - Maria I. Patrício
- Nuffield Laboratory of Ophthalmology, John Radcliffe Hospital, Oxford, United Kingdom
| | | | - Robert E. MacLaren
- Nuffield Laboratory of Ophthalmology, John Radcliffe Hospital, Oxford, United Kingdom
- Moorfields Eye Hospital, London, United Kingdom
| |
Collapse
|
31
|
Buck TM, Wijnholds J. Recombinant Adeno-Associated Viral Vectors (rAAV)-Vector Elements in Ocular Gene Therapy Clinical Trials and Transgene Expression and Bioactivity Assays. Int J Mol Sci 2020; 21:E4197. [PMID: 32545533 PMCID: PMC7352801 DOI: 10.3390/ijms21124197] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 06/09/2020] [Accepted: 06/10/2020] [Indexed: 02/06/2023] Open
Abstract
Inherited retinal dystrophies and optic neuropathies cause chronic disabling loss of visual function. The development of recombinant adeno-associated viral vectors (rAAV) gene therapies in all disease fields have been promising, but the translation to the clinic has been slow. The safety and efficacy profiles of rAAV are linked to the dose of applied vectors. DNA changes in the rAAV gene cassette affect potency, the expression pattern (cell-specificity), and the production yield. Here, we present a library of rAAV vectors and elements that provide a workflow to design novel vectors. We first performed a meta-analysis on recombinant rAAV elements in clinical trials (2007-2020) for ocular gene therapies. We analyzed 33 unique rAAV gene cassettes used in 57 ocular clinical trials. The rAAV gene therapy vectors used six unique capsid variants, 16 different promoters, and six unique polyadenylation sequences. Further, we compiled a list of promoters, enhancers, and other sequences used in current rAAV gene cassettes in preclinical studies. Then, we give an update on pro-viral plasmid backbones used to produce the gene therapy vectors, inverted terminal repeats, production yield, and rAAV safety considerations. Finally, we assess rAAV transgene and bioactivity assays applied to cells or organoids in vitro, explants ex vivo, and clinical studies.
Collapse
Affiliation(s)
- Thilo M. Buck
- Department of Ophthalmology, Leiden University Medical Center (LUMC), 2333 ZC Leiden, The Netherlands;
| | - Jan Wijnholds
- Department of Ophthalmology, Leiden University Medical Center (LUMC), 2333 ZC Leiden, The Netherlands;
- Netherlands Institute of Neuroscience, Royal Netherlands Academy of Arts and Sciences (KNAW), 1105 BA Amsterdam, The Netherlands
| |
Collapse
|
32
|
Maturana CJ, Verpeut JL, Pisano TJ, Dhanerawala ZM, Esteves A, Enquist LW, Engel EA. Small Alphaherpesvirus Latency-Associated Promoters Drive Efficient and Long-Term Transgene Expression in the CNS. Mol Ther Methods Clin Dev 2020; 17:843-857. [PMID: 32368565 PMCID: PMC7191541 DOI: 10.1016/j.omtm.2020.04.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 04/06/2020] [Indexed: 02/06/2023]
Abstract
Recombinant adeno-associated viruses (rAAVs) are used as gene therapy vectors to treat central nervous system (CNS) diseases. Despite their safety and broad tropism, important issues need to be corrected such as the limited payload capacity and the lack of small gene promoters providing long-term, pan-neuronal transgene expression in the CNS. Commonly used gene promoters are relatively large and can be repressed a few months after CNS transduction, risking the long-term performance of single-dose gene therapy applications. We used a whole-CNS screening approach based on systemic delivery of AAV-PHP.eB, iDisco+ tissue-clearing and light-sheet microscopy to identify three small latency-associated promoters (LAPs) from the herpesvirus pseudorabies virus (PRV). These promoters are LAP1 (404 bp), LAP2 (498 bp), and LAP1_2 (880 bp). They drive chronic transcription of the virus-encoded latency-associated transcript (LAT) during productive and latent phases of PRV infection. We observed stable, pan-neuronal transgene transcription and translation from AAV-LAPs in the CNS for 6 months post AAV transduction. In several CNS areas, the number of cells expressing the transgene was higher for LAP2 than the large conventional EF1α promoter (1,264 bp). Our data suggest that the LAPs are suitable candidates for viral vector-based CNS gene therapies requiring chronic transgene expression after one-time viral-vector administration.
Collapse
Affiliation(s)
- Carola J. Maturana
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ 08544, USA
| | - Jessica L. Verpeut
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ 08544, USA
| | - Thomas J. Pisano
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ 08544, USA
| | - Zahra M. Dhanerawala
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ 08544, USA
| | - Andrew Esteves
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Lynn W. Enquist
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Esteban A. Engel
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ 08544, USA
| |
Collapse
|
33
|
De La Camara CMF, Cehajic-Kapetanovic J, MacLaren RE. RPGR gene therapy presents challenges in cloning the coding sequence. Expert Opin Biol Ther 2020; 20:63-71. [PMID: 31612744 PMCID: PMC7104355 DOI: 10.1080/14712598.2020.1680635] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Introduction: Currently, there are three Phase I/II clinical trials based on gene therapy ongoing to test different AAV.RPGR or deleted RPGR vectors on patients affected by X-linked retinitis pigmentosa. These three vectors differ in the adeno-associated viral (AAV) vector capsid used, and the coding sequences: two contain codon optimized versions of RPGR which give the full-length protein, whilst the third uses a wild-type sequence that contains a large deletion encoding part of the functional domain of the RPGR protein.Areas covered: This review approaches the different studies that have led to the initiation of three different clinical trials for RPGR related X-linked retinitis pigmentosa.Expert opinion: The development of a gene therapy vector to deliver a normal copy of the RPGR gene into the photoreceptors has presented a challenge for the scientific community. The instability of its sequence and the fact that its function is not well understood can lead to the production of a nonfunctional or deleterious protein for the human retina. Since the RPGR protein undergoes post-translational glutamylation in the protein domain that may be particularly affected by gene instability, a functional assay of glutamylation is essential to verify the correct coding sequence.
Collapse
Affiliation(s)
- Cristina Martinez-Fernandez De La Camara
- Department of Clinical Neurosciences, Nuffield Laboratory of Ophthalmology, University of Oxford, John Radcliffe Hospital, Headley Way, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, John Radcliffe Hospital, Headley Way, UK
| | - Jasmina Cehajic-Kapetanovic
- Department of Clinical Neurosciences, Nuffield Laboratory of Ophthalmology, University of Oxford, John Radcliffe Hospital, Headley Way, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, John Radcliffe Hospital, Headley Way, UK
| | - Robert E. MacLaren
- Department of Clinical Neurosciences, Nuffield Laboratory of Ophthalmology, University of Oxford, John Radcliffe Hospital, Headley Way, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, John Radcliffe Hospital, Headley Way, UK
| |
Collapse
|
34
|
Jolly JK, Bridge H, MacLaren RE. Outcome Measures Used in Ocular Gene Therapy Trials: A Scoping Review of Current Practice. Front Pharmacol 2019; 10:1076. [PMID: 31620003 PMCID: PMC6759794 DOI: 10.3389/fphar.2019.01076] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2018] [Accepted: 08/23/2019] [Indexed: 12/14/2022] Open
Abstract
Multiple gene therapy trials are occurring for a variety of ophthalmic diseases around the world. The safety of gene therapy in the eye has been established, and the next step is to reliably assess efficacy. This is primarily done through the use of imaging techniques and visual function measures. Standardized visual function assessments, however, were originally developed for a clinical setting and may not be suitable for detecting and quantifying therapeutic changes. This scoping review takes a comprehensive look at current practice in terms of the outcome measures defined at trial registration. These were compared to the outcome measures reported in the literature. All published trials reported the pre-registered primary outcome measure. A range of additional secondary outcomes were reported that were not originally planned. Gaps in gene therapy assessment exist and further discussion are required to find a way forward, particularly as more conditions progress to phase 2 and 3 trials. Several factors impacting on trial design and outcome measure choice are discussed.
Collapse
Affiliation(s)
- Jasleen K Jolly
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom.,Wellcome Integrative Neuroimaging Centre, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom.,Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | - Holly Bridge
- Wellcome Integrative Neuroimaging Centre, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Robert E MacLaren
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom.,Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| |
Collapse
|
35
|
Domenger C, Grimm D. Next-generation AAV vectors—do not judge a virus (only) by its cover. Hum Mol Genet 2019; 28:R3-R14. [DOI: 10.1093/hmg/ddz148] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 05/30/2019] [Accepted: 06/17/2019] [Indexed: 12/11/2022] Open
Abstract
AbstractRecombinant adeno-associated viruses (AAV) are under intensive investigation in numerous clinical trials after they have emerged as a highly promising vector for human gene therapy. Best exemplifying their power and potential is the authorization of three gene therapy products based on wild-type AAV serotypes, comprising Glybera (AAV1), Luxturna (AAV2) and, most recently, Zolgensma (AAV9). Nonetheless, it has also become evident that the current AAV vector generation will require improvements in transduction potency, antibody evasion and cell/tissue specificity to allow the use of lower and safer vector doses. To this end, others and we devoted substantial previous research to the implementation and application of key technologies for engineering of next-generation viral capsids in a high-throughput ‘top-down’ or (semi-)rational ‘bottom-up’ approach. Here, we describe a set of recent complementary strategies to enhance features of AAV vectors that act on the level of the recombinant cargo. As examples that illustrate the innovative and synergistic concepts that have been reported lately, we highlight (i) novel synthetic enhancers/promoters that provide an unprecedented degree of AAV tissue specificity, (ii) pioneering genetic circuit designs that harness biological (microRNAs) or physical (light) triggers as regulators of AAV gene expression and (iii) new insights into the role of AAV DNA structures on vector genome stability, integrity and functionality. Combined with ongoing capsid engineering and selection efforts, these and other state-of-the-art innovations and investigations promise to accelerate the arrival of the next generation of AAV vectors and to solidify the unique role of this exciting virus in human gene therapy.
Collapse
Affiliation(s)
- Claire Domenger
- Department of Infectious Diseases/Virology, Heidelberg University Hospital, BioQuant Center, Im Neuenheimer Feld, Heidelberg, Germany
| | - Dirk Grimm
- Department of Infectious Diseases/Virology, Heidelberg University Hospital, BioQuant Center, Im Neuenheimer Feld, Heidelberg, Germany
- German Center for Infection Research (DZIF) and German Center for Cardiovascular Research (DZHK), Heidelberg, Germany
| |
Collapse
|
36
|
Chandler LC, Barnard AR, Caddy SL, Patrício MI, McClements ME, Fu H, Rada C, MacLaren RE, Xue K. Enhancement of Adeno-Associated Virus-Mediated Gene Therapy Using Hydroxychloroquine in Murine and Human Tissues. Mol Ther Methods Clin Dev 2019; 14:77-89. [PMID: 31309129 PMCID: PMC6606965 DOI: 10.1016/j.omtm.2019.05.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 05/20/2019] [Indexed: 12/20/2022]
Abstract
The therapeutic effects of gene therapy using adeno-associated virus (AAV) vectors are dependent on the efficacy of viral transduction. Currently, we have reached the safe limits of AAV vector dose, beyond which damaging inflammatory responses are seen. To improve the efficacy of AAV transduction, we treated mouse embryonic fibroblasts, primate retinal pigment epithelial cells, and human retinal explants with hydroxychloroquine (HCQ) 1 h prior to transduction with an AAV2 vector encoding GFP driven by a ubiquitous CAG promoter. This led to a consistent increase in GFP expression, up to 3-fold, compared with vector alone. Comparing subretinal injections of AAV2.CAG.GFP vector alone versus co-injection with 18.75 μM HCQ in paired eyes in mice, mean GFP expression was 4.6-fold higher in retinae co-treated with HCQ without retinal toxicity. A comparative 5.9-fold effect was seen with an AAV8(Y733F).GRK1.GFP vector containing the photoreceptor-specific rhodopsin kinase promoter. While the mechanism of action remains to be fully elucidated, our data suggest that a single pulse of adjunctive HCQ could safely improve AAV transduction in vivo, thus providing a novel strategy for enhancing the clinical effects of gene therapy.
Collapse
Affiliation(s)
- Laurel C. Chandler
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, NIHR Biomedical Research Centre, Oxford OX3 9DU, UK
| | - Alun R. Barnard
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, NIHR Biomedical Research Centre, Oxford OX3 9DU, UK
| | - Sarah L. Caddy
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | - Maria I. Patrício
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, NIHR Biomedical Research Centre, Oxford OX3 9DU, UK
| | - Michelle E. McClements
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - Howell Fu
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - Cristina Rada
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | - Robert E. MacLaren
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, NIHR Biomedical Research Centre, Oxford OX3 9DU, UK
| | - Kanmin Xue
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, NIHR Biomedical Research Centre, Oxford OX3 9DU, UK
- Corresponding author: Kanmin Xue, Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Level 6 West Wing, John Radcliffe Hospital, Headley Way, Oxford OX3 9DU, UK.
| |
Collapse
|
37
|
Ong T, Pennesi ME, Birch DG, Lam BL, Tsang SH. Adeno-Associated Viral Gene Therapy for Inherited Retinal Disease. Pharm Res 2019; 36:34. [PMID: 30617669 PMCID: PMC6534121 DOI: 10.1007/s11095-018-2564-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 12/13/2018] [Indexed: 01/17/2023]
Abstract
Inherited retinal diseases (IRDs) are a group of rare, heterogenous eye disorders caused by gene mutations that result in degeneration of the retina. There are currently limited treatment options for IRDs; however, retinal gene therapy holds great promise for the treatment of different forms of inherited blindness. One such IRD for which gene therapy has shown positive initial results is choroideremia, a rare, X-linked degenerative disorder of the retina and choroid. Mutation of the CHM gene leads to an absence of functional Rab escort protein 1 (REP1), which causes retinal pigment epithelium cell death and photoreceptor degeneration. The condition presents in childhood as night blindness, followed by progressive constriction of visual fields, generally leading to vision loss in early adulthood and total blindness thereafter. A recently developed adeno-associated virus-2 (AAV2) vector construct encoding REP1 (AAV2-REP1) has been shown to deliver a functional version of the CHM gene into the retinal pigment epithelium and photoreceptor cells. Phase 1 and 2 studies of AAV2-REP1 in patients with choroideremia have produced encouraging results, suggesting that it is possible not only to slow or stop the decline in vision following treatment with AAV2-REP1, but also to improve visual acuity in some patients.
Collapse
Affiliation(s)
- Tuyen Ong
- Nightstar Therapeutics, 203 Crescent Street, Suite 303, Waltham, Massachusetts, 02453, USA.
| | - Mark E Pennesi
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, USA
| | - David G Birch
- Retina Foundation of the Southwest, Dallas, Texas, USA
| | - Byron L Lam
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Stephen H Tsang
- Department of Ophthalmology and of Pathology and Cell Biology, Columbia University, New York, New York, USA
| |
Collapse
|
38
|
Lam BL, Davis JL, Gregori NZ, MacLaren RE, Girach A, Verriotto JD, Rodriguez B, Rosa PR, Zhang X, Feuer WJ. Choroideremia Gene Therapy Phase 2 Clinical Trial: 24-Month Results. Am J Ophthalmol 2019; 197:65-73. [PMID: 30240725 DOI: 10.1016/j.ajo.2018.09.012] [Citation(s) in RCA: 104] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2018] [Revised: 09/09/2018] [Accepted: 09/11/2018] [Indexed: 11/26/2022]
Abstract
PURPOSE To report the final results of a phase 2 high-dose gene therapy clinical trial in choroideremia. METHODS Design: Phase 2 clinical trial. PARTICIPANTS Six men (aged 32-72 years) with genetically-confirmed advanced choroideremia. Patients received subfoveal injection of AAV2-REP1 (1011 genome particles in 0.1 mL) in the worse-sighted eye. OUTCOME MEASURES Primary measure was best-corrected visual acuity (BCVA) change from baseline in the treated eye compared to the untreated eye. Secondary endpoints included change from baseline in microperimetry, fundus autofluorescence, and spectral-domain optical coherence tomography (OCT). Safety evaluations included adverse events, viral shedding in body fluids, and vector antibody responses. RESULTS Baseline mean ETDRS BCVA was 65.3 ± 8.8 (SD, range 56-77, 20/32-20/80) letters in the treated eyes and 77.0 ± 4.2 (69-81, 20/25-20/40) letters in the untreated eyes. At 2 years, 1 treated eye improved by 10 letters and another by 5 letters, while 1 untreated eye improved by 4 letters. All other eyes were within 2 letters of baseline. Baseline microperimetry sensitivities in the treated eyes were poor (1.2 ± 2.1 (0, 5.1) dB) and showed no significant change. No serious adverse event occurred. Two patients developed an atrophic retinal hole in a nonfunctioning macular area where baseline OCT showed preexisting thinning. Intraoperative microscope-integrated OCT allowed proper subretinal injection with avoidance of excessive foveal stretching and macular hole formation. CONCLUSIONS Sustained improvement or maintenance of BCVA is achievable in choroideremia with high-dose AAV2-REP1, indicating BCVA is a viable primary outcome in advanced choroideremia. Choroideremia gene therapy delivered with intraoperative OCT has a good safety profile.
Collapse
|
39
|
Xue K, Jolly JK, Barnard AR, Rudenko A, Salvetti AP, Patrício MI, Edwards TL, Groppe M, Orlans HO, Tolmachova T, Black GC, Webster AR, Lotery AJ, Holder GE, Downes SM, Seabra MC, MacLaren RE. Beneficial effects on vision in patients undergoing retinal gene therapy for choroideremia. Nat Med 2018; 24:1507-1512. [PMID: 30297895 PMCID: PMC7032956 DOI: 10.1038/s41591-018-0185-5] [Citation(s) in RCA: 117] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 08/06/2018] [Indexed: 11/09/2022]
Abstract
Retinal gene therapy is increasingly recognized as a novel molecular intervention that has huge potential in treating common causes of blindness, the majority of which have a genetic aetiology1-5. Choroideremia is a chronic X-linked retinal degeneration that was first described in 18726. It leads to progressive blindness due to deficiency of Rab-escort protein 1 (REP1). We designed an adeno-associated viral vector to express REP1 and assessed it in a gene therapy clinical trial by subretinal injection in 14 patients with choroideremia. The primary endpoint was vision change in treated eyes 2 years after surgery compared to unoperated fellow eyes. Despite complications in two patients, visual acuity improved in the 14 treated eyes over controls (median 4.5 letter gain, versus 1.5 letter loss, P = 0.04), with 6 treated eyes gaining more than one line of vision (>5 letters). The results suggest that retinal gene therapy can sustain and improve visual acuity in a cohort of predominantly late-stage choroideremia patients in whom rapid visual acuity loss would ordinarily be predicted.
Collapse
Affiliation(s)
- Kanmin Xue
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Jasleen K Jolly
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Alun R Barnard
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Anna Rudenko
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Anna P Salvetti
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Maria I Patrício
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Thomas L Edwards
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Markus Groppe
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Harry O Orlans
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Tanya Tolmachova
- Molecular Medicine Section, National Heart and Lung Institute, Imperial College, London, UK
| | - Graeme C Black
- Division of Evolution and Genomic Sciences, Neuroscience and Mental Health Domain, Manchester Centre for Genomic Medicine, University Hospitals NHS Foundation Trust and Academic Health Sciences Centre, St Mary's Hospital, Manchester, UK
| | - Andrew R Webster
- Moorfields Eye Hospital NHS Foundation Trust, London, UK
- University College London Institute of Ophthalmology, London, UK
| | - Andrew J Lotery
- Clinical Neurosciences Group, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Graham E Holder
- Moorfields Eye Hospital NHS Foundation Trust, London, UK
- University College London Institute of Ophthalmology, London, UK
- Department of Ophthalmology, National University of Singapore, Singapore, Singapore
| | - Susan M Downes
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Miguel C Seabra
- University College London Institute of Ophthalmology, London, UK
- Chronic Diseases Research Centre, Nova Medical School, Universidade Nova de Lisboa, Lisbon, Portugal
| | - Robert E MacLaren
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK.
- Moorfields Eye Hospital NHS Foundation Trust, London, UK.
| |
Collapse
|
40
|
Simunovic MP, Shen W, Lin JY, Protti DA, Lisowski L, Gillies MC. Optogenetic approaches to vision restoration. Exp Eye Res 2018; 178:15-26. [PMID: 30218651 DOI: 10.1016/j.exer.2018.09.003] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 08/16/2018] [Accepted: 09/07/2018] [Indexed: 10/28/2022]
Abstract
Inherited retinal disease (IRD) affects about 1 in 3000 to 1 in 5000 individuals and is now believed to be the most common cause of blindness registration in developed countries. Until recently, the management of such conditions had been exclusively supportive. However, advances in molecular biology and medical engineering have now seen the rise of a variety of approaches to restore vision in patients with IRDs. Optogenetic approaches are primarily aimed at rendering secondary and tertiary neurons of the retina light-sensitive in order to replace degenerate or dysfunctional photoreceptors. Such approaches are attractive because they provide a "causative gene-independent" strategy, which may prove suitable for a variety of patients with IRD. We discuss theoretical and practical considerations in the selection of optogenetic molecules, vectors, surgical approaches and review previous trials of optogenetics for vision restoration. Optogenetic approaches to vision restoration have yielded promising results in pre-clinical trials and a phase I/II clinical trial is currently underway (ClinicalTrials.gov NCT02556736). Despite the significant inroads made in recent years, the ideal optogenetic molecule, vector and surgical approach have yet to be established.
Collapse
Affiliation(s)
- M P Simunovic
- Save Sight Institute, University of Sydney, 8 Macquarie St., Sydney, NSW, 2000, Australia; Retinal Unit, Sydney Eye Hospital, 8 Macquarie St., Sydney, NSW, 2000, Australia.
| | - W Shen
- Retinal Unit, Sydney Eye Hospital, 8 Macquarie St., Sydney, NSW, 2000, Australia
| | - J Y Lin
- Faculty of Health, University of Tasmania, Private Bag 23, Hobart, TAS, 7000, Australia
| | - D A Protti
- Discipline of Physiology, University of Sydney, NSW, 2006, Australia
| | - L Lisowski
- Children's Medical Research Institute, University of Sydney, NSW, 2006, Australia; Military Institute of Hygiene and Epidemiology, 24-100, Puławy, Poland
| | - M C Gillies
- Save Sight Institute, University of Sydney, 8 Macquarie St., Sydney, NSW, 2000, Australia; Retinal Unit, Sydney Eye Hospital, 8 Macquarie St., Sydney, NSW, 2000, Australia
| |
Collapse
|
41
|
Dimopoulos IS, Hoang SC, Radziwon A, Binczyk NM, Seabra MC, MacLaren RE, Somani R, Tennant MT, MacDonald IM. Two-Year Results After AAV2-Mediated Gene Therapy for Choroideremia: The Alberta Experience. Am J Ophthalmol 2018; 193:130-142. [PMID: 29940166 DOI: 10.1016/j.ajo.2018.06.011] [Citation(s) in RCA: 119] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 06/12/2018] [Accepted: 06/13/2018] [Indexed: 10/28/2022]
Abstract
PURPOSE To assess the safety of a recombinant adeno-associated viral vector expressing REP1 (rAAV2.REP1) in choroideremia subjects. METHODS Design: Phase I clinical trial. PARTICIPANTS Six adult male subjects, 30-42 years of age, with genetically confirmed choroideremia (CHM) were enrolled. The eye with the worse vision, for all subjects, received a single subfoveal injection of 0.1 mL rAAV2.REP1 containing 1011 genome particles. Subjects were followed up for 2 years thereafter. OUTCOME MEASURES The primary outcome measure was safety, determined by the number of ocular and systemic adverse events assessed by ophthalmic examination, spectral-domain optical coherence tomography (SD-OCT), and short-wavelength autofluorescence (FAF). Secondary outcome measures were the change from baseline in best-corrected visual acuity (BCVA) in the treated eye compared to the untreated eye, changes in visual function using microperimetry, and the area of retinal pigment epithelium (RPE) preservation by FAF. RESULTS One subject had an 8-ETDRS-letter BCVA loss from baseline measured at 24 months, while 1 subject had a ≥15-letter BCVA gain. A similar improvement was noted in the untreated eye of another subject throughout the follow-up period. Microperimetry sensitivity showed no improvement or significant change up to 2 years after vector administration. The area of preserved RPE as measured by FAF was noted to decline at a similar rate between the treated and untreated eyes. One subject experienced a serious adverse event: a localized intraretinal immune response, resulting in marked decline in visual function and loss of SD-OCT outer retinal structures. CONCLUSIONS One serious adverse event was experienced in 6 subjects treated with a subfoveal injection of AAV2.REP1. The area of remaining functional RPE in the treated eye and untreated eye declined at the same rate over a 2-year period. Fundus autofluorescence area is a remarkably predictive biomarker and objective outcome measure for future studies of ocular gene therapy in CHM subjects.
Collapse
|
42
|
Patrício MI, Barnard AR, Xue K, MacLaren RE. Choroideremia: molecular mechanisms and development of AAV gene therapy. Expert Opin Biol Ther 2018; 18:807-820. [DOI: 10.1080/14712598.2018.1484448] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Maria I Patrício
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
- National Institute for Health Research (NIHR) Oxford Biomedical Research Centre (BRC), Oxford, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Alun R Barnard
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
- National Institute for Health Research (NIHR) Oxford Biomedical Research Centre (BRC), Oxford, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Kanmin Xue
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
- National Institute for Health Research (NIHR) Oxford Biomedical Research Centre (BRC), Oxford, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Robert E MacLaren
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
- National Institute for Health Research (NIHR) Oxford Biomedical Research Centre (BRC), Oxford, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| |
Collapse
|
43
|
DiCarlo JE, Mahajan VB, Tsang SH. Gene therapy and genome surgery in the retina. J Clin Invest 2018; 128:2177-2188. [PMID: 29856367 DOI: 10.1172/jci120429] [Citation(s) in RCA: 95] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Precision medicine seeks to treat disease with molecular specificity. Advances in genome sequence analysis, gene delivery, and genome surgery have allowed clinician-scientists to treat genetic conditions at the level of their pathology. As a result, progress in treating retinal disease using genetic tools has advanced tremendously over the past several decades. Breakthroughs in gene delivery vectors, both viral and nonviral, have allowed the delivery of genetic payloads in preclinical models of retinal disorders and have paved the way for numerous successful clinical trials. Moreover, the adaptation of CRISPR-Cas systems for genome engineering have enabled the correction of both recessive and dominant pathogenic alleles, expanding the disease-modifying power of gene therapies. Here, we highlight the translational progress of gene therapy and genome editing of several retinal disorders, including RPE65-, CEP290-, and GUY2D-associated Leber congenital amaurosis, as well as choroideremia, achromatopsia, Mer tyrosine kinase- (MERTK-) and RPGR X-linked retinitis pigmentosa, Usher syndrome, neovascular age-related macular degeneration, X-linked retinoschisis, Stargardt disease, and Leber hereditary optic neuropathy.
Collapse
Affiliation(s)
- James E DiCarlo
- Jonas Children's Vision Care and Bernard and Shirlee Brown Glaucoma Laboratory, Columbia Stem Cell Initiative, Departments of Ophthalmology, Pathology and Cell Biology, Institute of Human Nutrition, College of Physicians and Surgeons, Columbia University, New York, New York, USA.,Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, New York, USA
| | - Vinit B Mahajan
- Omics Laboratory, Byers Eye Institute, Department of Ophthalmology, Stanford University, Palo Alto, California, USA.,Veterans Affairs Palo Alto Health Care System, Palo Alto, California, USA
| | - Stephen H Tsang
- Jonas Children's Vision Care and Bernard and Shirlee Brown Glaucoma Laboratory, Columbia Stem Cell Initiative, Departments of Ophthalmology, Pathology and Cell Biology, Institute of Human Nutrition, College of Physicians and Surgeons, Columbia University, New York, New York, USA.,Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, New York, USA
| |
Collapse
|
44
|
Xue K, MacLaren RE. Ocular gene therapy for choroideremia: clinical trials and future perspectives. EXPERT REVIEW OF OPHTHALMOLOGY 2018; 13:129-138. [PMID: 31105764 DOI: 10.1080/17469899.2018.1475232] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
Introduction Gene therapy offers the potential for targeted replacement of single gene defects in inherited retinal degenerations. Areas covered Choroideremia is an X-linked blinding retinal disease resulting from deficiency of the CHM gene product, REP1. The disease represents an ideal target for retinal gene therapy, as it is readily diagnosed in the clinic, relatively homogenous in phenotype and slow progressing, thereby providing a wide therapeutic window for intervention. Ongoing clinical trials of retinal gene therapy for choroideremia using an adeno-associated viral vector have demonstrated safety and early efficacy. We review the clinical characteristics of the disease with a view to interpreting the findings of gene therapy clinical trials and discuss future directions. Expert commentary Choroideremia gene therapy has so far demonstrated good safety profile and early functional visual acuity gains in a proportion of trial participants, which appear to be sustained.
Collapse
Affiliation(s)
- Kanmin Xue
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford & Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Robert E MacLaren
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford & Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| |
Collapse
|
45
|
Orlans HO, Edwards TL, De Silva SR, Patrício MI, MacLaren RE. Human Retinal Explant Culture for Ex Vivo Validation of AAV Gene Therapy. Methods Mol Biol 2018; 1715:289-303. [PMID: 29188522 DOI: 10.1007/978-1-4939-7522-8_21] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Recombinant adeno-associated viral (AAV) vectors have been successfully employed as the mode of gene delivery in several clinical trials for the treatment of inherited retinal diseases to date. The design of such vectors is critical in determining cellular tropism and level of subsequent gene expression that may be achieved following viral delivery. Here we describe a system for living retinal tissue extraction, ex vivo culture, viral transduction and assessment of transgene expression that may be used to assess viral constructs for gene therapy in the human retina at a preclinical stage.
Collapse
Affiliation(s)
- Harry O Orlans
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, UK.
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK.
- Moorfields Eye Hospital, London, UK.
| | - Thomas L Edwards
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Samantha R De Silva
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Maria I Patrício
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, UK
| | - Robert E MacLaren
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
- Moorfields Eye Hospital, London, UK
| |
Collapse
|
46
|
Hassall MM, Barnard AR, MacLaren RE. Gene Therapy for Color Blindness. THE YALE JOURNAL OF BIOLOGY AND MEDICINE 2017; 90:543-551. [PMID: 29259520 PMCID: PMC5733843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Achromatopsia is a rare congenital cause of vision loss due to isolated cone photoreceptor dysfunction. The most common underlying genetic mutations are autosomal recessive changes in CNGA3, CNGB3, GNAT2, PDE6H, PDE6C, or ATF6. Animal models of Cnga3, Cngb3, and Gnat2 have been rescued using AAV gene therapy; showing partial restoration of cone electrophysiology and integration of this new photopic vision in reflexive and behavioral visual tests. Three gene therapy phase I/II trials are currently being conducted in human patients in the USA, the UK, and Germany. This review details the AAV gene therapy treatments of achromatopsia to date. We also present novel data showing rescue of a Cnga3-/- mouse model using an rAAV.CBA.CNGA3 vector. We conclude by synthesizing the implications of this animal work for ongoing human trials, particularly, the challenge of restoring integrated cone retinofugal pathways in an adult visual system. The evidence to date suggests that gene therapy for achromatopsia will need to be applied early in childhood to be effective.
Collapse
Affiliation(s)
- Mark M. Hassall
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, UK,Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK,To whom all correspondence should be addressed: Dr. Mark M. Hassall, Nuffield Laboratory of Ophthalmology, Level 6, West Wing, John Radcliffe Hospital, Headley Way, Oxford, UK, OX3 9DU, Tel: +44 1865 234768, .
| | - Alun R. Barnard
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, UK,Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Robert E. MacLaren
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, UK,Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| |
Collapse
|
47
|
Salvetti AP, Patrício MI, Barnard AR, Orlans HO, Hickey DG, MacLaren RE. Impact of Vital Dyes on Cell Viability and Transduction Efficiency of AAV Vectors Used in Retinal Gene Therapy Surgery: An In Vitro and In Vivo Analysis. Transl Vis Sci Technol 2017; 6:4. [PMID: 28706756 PMCID: PMC5505121 DOI: 10.1167/tvst.6.4.4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 05/29/2017] [Indexed: 12/20/2022] Open
Abstract
Purpose Treatment of inherited retinal degenerations using adeno-associated viral (AAV) vectors involves delivery by subretinal injection. In the latter stages, alteration of normal anatomy may cause difficulty in visualizing the retinotomy, retinal detachment extension, and vector diffusion. Vital dyes may be useful surgical adjuncts, but their safety and impact on AAV transduction are largely unknown. Methods The effects of Sodium Fluorescein (SF), Membrane Blue (MB), and Membrane Blue Dual (DB) at a range of dilutions were assessed on human embryonic kidney cells in vitro using an AAV2-green fluorescent protein (GFP) reporter at different multiplicities of infection. Flow cytometry analysis was performed to assess both cell viability and transduction efficiency. The effect on quantitative (q)PCR titer was determined. Balanced salt solution (BSS) or dilute DB (1:5 in BSS) were delivered subretinally into left/right eyes of C57BL/6J mice (n = 12). Retinal structure and function were analyzed by optical coherence tomography, autofluorescence, dark-and light-adapted full-field electroretinography. Results DB and MB were not toxic at any concentration tested, SF only when undiluted. The presence of dyes did not adversely affect the genomic titer. DB even increased the values, due to presence of surfactant in the formulation. AAV2-GFP transduction efficiency was not reduced by the dyes. No structural and functional toxic effects were observed following subretinal delivery of DB. Conclusions Only undiluted SF affected cell viability. No effects on qPCR titer and transduction efficiency were observed. DB does not appear toxic when delivered subretinally and improves titer accuracy. DB may therefore be a safe and helpful adjunct during gene therapy surgery. Translational Relevance This paper might be of interest to the retinal gene therapy community: it is a “bench to bedside” research paper about the potential use of dyes as a surgical adjunct during the gene therapy surgery. We have tested the potential toxicity and impact on transduction efficiency in an in vitro and in vivo model.
Collapse
Affiliation(s)
- Anna P Salvetti
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences & NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, UK.,Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Maria I Patrício
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences & NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, UK.,Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Alun R Barnard
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences & NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, UK.,Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Harry O Orlans
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences & NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, UK.,Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Doron G Hickey
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences & NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, UK
| | - Robert E MacLaren
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences & NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, UK.,Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| |
Collapse
|