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Whitehead M, Sage A, Burgoyne T, Osborne A, Yu-Wai-Man P, Martin KR. Immunobiology of a rationally-designed AAV2 capsid following intravitreal delivery in mice. Gene Ther 2023; 30:723-735. [PMID: 37386155 PMCID: PMC10506909 DOI: 10.1038/s41434-023-00409-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 05/22/2023] [Accepted: 06/12/2023] [Indexed: 07/01/2023]
Abstract
Adeno-associated virus serotype 2 (AAV2) is a viral vector that can be used to deliver therapeutic genes to diseased cells in the retina. One strategy for altering AAV2 vectors involves the mutation of phosphodegron residues, which are thought to be phosphorylated/ubiquitinated in the cytosol, facilitating degradation of the vector and the inhibition of transduction. As such, mutation of phosphodegron residues have been correlated with increased transduction of target cells, however, an assessment of the immunobiology of wild-type and phosphodegron mutant AAV2 vectors following intravitreal (IVT) delivery to immunocompetent animals is lacking in the current literature. In this study, we show that IVT of a triple phosphodegron mutant AAV2 capsid is associated with higher levels of humoral immune activation, infiltration of CD4 and CD8 T-cells into the retina, generation of splenic germinal centre reactions, activation of conventional dendritic cell subsets, and elevated retinal gliosis compared to wild-type AAV2 capsids. However, we did not detect significant changes in electroretinography arising after vector administration. We also demonstrate that the triple AAV2 mutant capsid is less susceptible to neutralisation by soluble heparan sulphate and anti-AAV2 neutralising antibodies, highlighting a possible utility for the vector in terms of circumventing pre-existing humoral immunity. In summary, the present study highlights novel aspects of rationally-designed vector immunobiology, which may be relevant to their application in preclinical and clinical settings.
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Affiliation(s)
- Michael Whitehead
- John Van Geest Centre for Brain Repair, Department of Clinical Neuroscience, University of Cambridge, Cambridge, UK.
| | - Andrew Sage
- Division of Cardiovascular Medicine, University of Cambridge, Addenbrooke's Hospital, Hills Road, Cambridge, UK
| | - Tom Burgoyne
- UCL Institute of Ophthalmology, London, UK
- Paediatric Respiratory Medicine, Primary Ciliary Dyskinesia Centre, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Andrew Osborne
- John Van Geest Centre for Brain Repair, Department of Clinical Neuroscience, University of Cambridge, Cambridge, UK
| | - Patrick Yu-Wai-Man
- John Van Geest Centre for Brain Repair, Department of Clinical Neuroscience, University of Cambridge, Cambridge, UK
- MRC Mitochondrial Biology Unit, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
- NIHR Biomedical Research Centre at Moorfields Eye Hospital and UCL Institute of Ophthalmology, London, UK
| | - Keith R Martin
- John Van Geest Centre for Brain Repair, Department of Clinical Neuroscience, University of Cambridge, Cambridge, UK
- Wellcome Trust-MRC Cambridge Stem Cell Institute, 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
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Pozarickij A, Williams C, Hysi PG, Guggenheim JA. Quantile regression analysis reveals widespread evidence for gene-environment or gene-gene interactions in myopia development. Commun Biol 2019; 2:167. [PMID: 31069276 PMCID: PMC6502837 DOI: 10.1038/s42003-019-0387-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 03/15/2019] [Indexed: 12/18/2022] Open
Abstract
A genetic contribution to refractive error has been confirmed by the discovery of more than 150 associated variants in genome-wide association studies (GWAS). Environmental factors such as education and time outdoors also demonstrate strong associations. Currently however, the extent of gene-environment or gene-gene interactions in myopia is unknown. We tested the hypothesis that refractive error-associated variants exhibit effect size heterogeneity, a hallmark feature of genetic interactions. Of 146 variants tested, evidence of non-uniform, non-linear effects were observed for 66 (45%) at Bonferroni-corrected significance (P < 1.1 × 10-4) and 128 (88%) at nominal significance (P < 0.05). LAMA2 variant rs12193446, for example, had an effect size varying from -0.20 diopters (95% CI -0.18 to -0.23) to -0.89 diopters (95% CI -0.71 to -1.07) in different individuals. SNP effects were strongest at the phenotype extremes and weaker in emmetropes. A parsimonious explanation for these findings is that gene-environment or gene-gene interactions in myopia are pervasive.
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Affiliation(s)
- Alfred Pozarickij
- School of Optometry & Vision Sciences, Cardiff University, Cardiff, CF24 4HQ UK
| | - Cathy Williams
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, BS8 2BN UK
| | - Pirro G. Hysi
- Department of Ophthalmology, King’s College London, St. Thomas’ Hospital, London, SE1 7EH UK
- Department of Twin & Genetic Epidemiology, King’s College London, St. Thomas’ Hospital, London, SE1 7EH UK
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