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Ertl HCJ. Circumventing B Cell Responses to Allow for Redosing of Adeno-Associated Virus Vectors. Hum Gene Ther 2023. [PMID: 37861281 DOI: 10.1089/hum.2023.162] [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: 10/21/2023] Open
Abstract
Adeno-associated virus (AAV)-mediated gene therapy has made significant progress in the last few decades. Nevertheless, challenges imposed by the immune system remain. The very high doses of AAV vectors used for some disorders have resulted in serious adverse events (SAEs) or even deaths, demonstrating that AAV vector doses that can safely be injected into patients are limited and for some indications below the therapeutic dose. Currently used immunosuppressive drugs have not prevented the SAEs, indicating that it may be prudent to treat patients with repeated transfer of moderate doses rather than a single injection of high doses of AAV vectors. The former approach has been avoided as AAV vectors elicit neutralizing antibodies that prevent successful reapplication of serologically crossreactive vectors. Immunosuppressive regimens that block B cell responses to AAV vectors or treatments that remove AAV neutralizing antibodies thus need to be developed to allow for a shift from toxic single-dose injections of AAV vectors to repeated treatments with more moderate and safe doses. Preventing or blocking antibody responses would also allow for redosing of patients with declining transgene product expression, or for effective AAV-mediated gene transfer into patients with the pre-existing neutralizing antibodies.
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Affiliation(s)
- Hildegund C J Ertl
- Vaccine and Immunotherapy Center, Wistar Institute, Philadelphia, Pennsylvania, USA
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2
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Ertl HCJ. Mitigating Serious Adverse Events in Gene Therapy with AAV Vectors: Vector Dose and Immunosuppression. Drugs 2023; 83:287-298. [PMID: 36715794 DOI: 10.1007/s40265-023-01836-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/12/2023] [Indexed: 01/31/2023]
Abstract
Gene transfer with high doses of adeno-associated viral (AAV) vectors has resulted in serious adverse events and even death of the recipients. Toxicity could most likely be circumvented by repeated injections of lower and less toxic doses of vectors. This has not been pursued as AAV vectors induce potent neutralizing antibodies, which prevent cell transduction upon reinjection of the same vector. This review discusses different types of immune responses against AAV vectors and how they offer targets for the elimination or inhibition of vector-specific neutralizing antibodies. Such antibodies can be circumvented by using different virus serotypes for sequential injections, they can be removed by plasmapheresis, or they can be destroyed by enzymatic degradation. Antibody producing cells can be eliminated by proteasome inhibitors. Drugs that inhibit T-cell responses, B-cell signaling, or presentation of the vector's antigens to B cells can prevent or reduce induction of AAV-specific antibodies. Combinations of different approaches and drugs are likely needed to suppress or eliminate neutralizing antibodies, which would then allow for repeated dosing. Alternatively, novel AAV vectors with higher transduction efficacy are being developed and may allow for a dose reduction, although it remains unknown if this will completely address the problem of high-dose adverse events.
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Whitehead M, Osborne A, Yu-Wai-Man P, Martin K. Humoral immune responses to AAV gene therapy in the ocular compartment. Biol Rev Camb Philos Soc 2021; 96:1616-1644. [PMID: 33837614 DOI: 10.1111/brv.12718] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 03/25/2021] [Accepted: 03/25/2021] [Indexed: 12/11/2022]
Abstract
Viral vectors can be utilised to deliver therapeutic genes to diseased cells. Adeno-associated virus (AAV) is a commonly used viral vector that is favoured for its ability to infect a wide range of tissues whilst displaying limited toxicity and immunogenicity. Most humans harbour anti-AAV neutralising antibodies (NAbs) due to subclinical infections by wild-type virus during infancy and these pre-existing NAbs can limit the efficiency of gene transfer depending on the target cell type, route of administration and choice of serotype. Vector administration can also result in de novo NAb synthesis that could limit the opportunity for repeated gene transfer to diseased sites. A number of strategies have been described in preclinical models that could circumvent NAb responses in humans, however, the successful translation of these innovations into the clinical arena has been limited. Here, we provide a comprehensive review of the humoral immune response to AAV gene therapy in the ocular compartment. We cover basic AAV biology and clinical application, the role of pre-existing and induced NAbs, and possible approaches to overcoming antibody responses. We conclude with a framework for a comprehensive strategy for circumventing humoral immune responses to AAV in the future.
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Affiliation(s)
- Michael Whitehead
- John Van Geest Centre for Brain Repair, Department of Clinical Neuroscience, University of Cambridge, Cambridge, U.K
| | - Andrew Osborne
- John Van Geest Centre for Brain Repair, Department of Clinical Neuroscience, University of Cambridge, Cambridge, U.K
| | - Patrick Yu-Wai-Man
- John Van Geest Centre for Brain Repair, Department of Clinical Neuroscience, University of Cambridge, Cambridge, U.K.,MRC Mitochondrial Biology Unit, Department of Clinical Neurosciences, University of Cambridge, Cambridge, U.K.,NIHR Biomedical Research Centre at Moorfields Eye Hospital and UCL Institute of Ophthalmology, London, U.K
| | - Keith Martin
- John Van Geest Centre for Brain Repair, Department of Clinical Neuroscience, University of Cambridge, Cambridge, U.K.,Wellcome Trust-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, U.K.,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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4
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Orefice NS. Development of New Strategies Using Extracellular Vesicles Loaded with Exogenous Nucleic Acid. Pharmaceutics 2020; 12:E705. [PMID: 32722622 PMCID: PMC7464422 DOI: 10.3390/pharmaceutics12080705] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 07/19/2020] [Accepted: 07/24/2020] [Indexed: 12/13/2022] Open
Abstract
Gene therapy is a therapeutic strategy of delivering foreign genetic material (encoding for an important protein) into a patient's target cell to replace a defective gene. Nucleic acids are embedded within the adeno-associated virus (AAVs) vectors; however, preexisting immunity to AAVs remains a significant concern that impairs their clinical application. Extracellular vesicles (EVs) hold great potential for therapeutic applications as vectors of nucleic acids due to their endogenous intercellular communication functions through their cargo delivery, including lipids and proteins. So far, small RNAs (siRNA and micro (mi)RNA) have been mainly loaded into EVs to treat several diseases, but the potential use of EVs to load and deliver exogenous plasmid DNA has not been thoroughly described. This review provides a comprehensive overview of the principal methodologies currently employed to load foreign genetic material into EVs, highlighting the need to find the most effective strategies for their successful clinical translations.
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Affiliation(s)
- Nicola Salvatore Orefice
- Department of Medicine, University of Wisconsin-Madison, Madison, WI 53705, USA; or ; Tel.: +1-608-262-21-89
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA
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5
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Management of Neuroinflammatory Responses to AAV-Mediated Gene Therapies for Neurodegenerative Diseases. Brain Sci 2020; 10:brainsci10020119. [PMID: 32098339 PMCID: PMC7071492 DOI: 10.3390/brainsci10020119] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 02/17/2020] [Accepted: 02/20/2020] [Indexed: 12/12/2022] Open
Abstract
Recently, adeno-associated virus (AAV)-mediated gene therapies have attracted clinical interest for treating neurodegenerative diseases including spinal muscular atrophy (SMA), Canavan disease (CD), Parkinson’s disease (PD), and Friedreich’s ataxia (FA). The influx of clinical findings led to the first approved gene therapy for neurodegenerative disorders in 2019 and highlighted new safety concerns for patients. Large doses of systemically administered AAV stimulate host immune responses, resulting in anti-capsid and anti-transgene immunity with implications for transgene expression, treatment longevity, and patient safety. Delivering lower doses directly to the central nervous system (CNS) is a promising alternative, resulting in higher transgene expression with decreased immune responses. However, neuroinflammatory responses after CNS-targeted delivery of AAV are a critical concern. Reported signs of AAV-associated neuroinflammation in preclinical studies include dorsal root ganglion (DRG) and spinal cord pathology with mononuclear cell infiltration. In this review, we discuss ways to manage neuroinflammation, including choice of AAV capsid serotypes, CNS-targeting routes of delivery, genetic modifications to the vector and/or transgene, and adding immunosuppressive strategies to clinical protocols. As additional gene therapies for neurodegenerative diseases enter clinics, tracking biomarkers of neuroinflammation will be important for understanding the impact immune reactions can have on treatment safety and efficacy.
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Immune Response Mechanisms against AAV Vectors in Animal Models. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2019; 17:198-208. [PMID: 31970198 PMCID: PMC6965504 DOI: 10.1016/j.omtm.2019.12.008] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Early preclinical studies in rodents and other species did not reveal that vector or transgene immunity would present a significant hurdle for sustained gene expression. While there was early evidence of mild immune responses to adeno-associated virus (AAV) in preclinical studies, it was generally believed that these responses were too weak and transient to negatively impact sustained transduction. However, translation of the cumulative success in treating hemophilia B in rodents and dogs with an AAV2-F9 vector to human studies was not as successful. Despite significant progress in recent clinical trials for hemophilia, new immunotoxicities to AAV and transgene are emerging in humans that require better animal models to assess and overcome these responses. The animal models designed to address these immune complications have provided critical information to assess how vector dose, vector capsid processing, vector genome, difference in serotypes, and variations in vector delivery route can impact immunity and to develop approaches for overcoming pre-existing immunity. Additionally, a comprehensive dissection of innate, adaptive, and regulatory responses to AAV vectors in preclinical studies has provided a framework that can be utilized for development of immunomodulatory therapies to overcome or bypass immune responses and for developing strategic approaches toward engineering stealth AAV vectors that can circumvent immunity.
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Zabaleta N, Hommel M, Salas D, Gonzalez-Aseguinolaza G. Genetic-Based Approaches to Inherited Metabolic Liver Diseases. Hum Gene Ther 2019; 30:1190-1203. [DOI: 10.1089/hum.2019.140] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Affiliation(s)
- Nerea Zabaleta
- Gene Therapy and Regulation of Gene Expression Program, Centro de Investigación Médica Aplicada, IDISNA, Universidad de Navarra, Pamplona, Spain
| | - Mirja Hommel
- Gene Therapy and Regulation of Gene Expression Program, Centro de Investigación Médica Aplicada, IDISNA, Universidad de Navarra, Pamplona, Spain
| | - David Salas
- Gene Therapy and Regulation of Gene Expression Program, Centro de Investigación Médica Aplicada, IDISNA, Universidad de Navarra, Pamplona, Spain
| | - Gloria Gonzalez-Aseguinolaza
- Gene Therapy and Regulation of Gene Expression Program, Centro de Investigación Médica Aplicada, IDISNA, Universidad de Navarra, Pamplona, Spain
- Vivet Therapeutics, Pamplona, Spain
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Selot R, Arumugam S, Mary B, Cheemadan S, Jayandharan GR. Optimized AAV rh.10 Vectors That Partially Evade Neutralizing Antibodies during Hepatic Gene Transfer. Front Pharmacol 2017; 8:441. [PMID: 28769791 PMCID: PMC5511854 DOI: 10.3389/fphar.2017.00441] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 06/20/2017] [Indexed: 12/12/2022] Open
Abstract
Of the 12 common serotypes used for gene delivery applications, Adeno-associated virus (AAV)rh.10 serotype has shown sustained hepatic transduction and has the lowest seropositivity in humans. We have evaluated if further modifications to AAVrh.10 at its phosphodegron like regions or predicted immunogenic epitopes could improve its hepatic gene transfer and immune evasion potential. Mutant AAVrh.10 vectors were generated by site directed mutagenesis of the predicted targets. These mutant vectors were first tested for their transduction efficiency in HeLa and HEK293T cells. The optimal vector was further evaluated for their cellular uptake, entry, and intracellular trafficking by quantitative PCR and time-lapse confocal microscopy. To evaluate their potential during hepatic gene therapy, C57BL/6 mice were administered with wild-type or optimal mutant AAVrh.10 and the luciferase transgene expression was documented by serial bioluminescence imaging at 14, 30, 45, and 72 days post-gene transfer. Their hepatic transduction was further verified by a quantitative PCR analysis of AAV copy number in the liver tissue. The optimal AAVrh.10 vector was further evaluated for their immune escape potential, in animals pre-immunized with human intravenous immunoglobulin. Our results demonstrate that a modified AAVrh.10 S671A vector had enhanced cellular entry (3.6 fold), migrate rapidly to the perinuclear region (1 vs. >2 h for wild type vectors) in vitro, which further translates to modest increase in hepatic gene transfer efficiency in vivo. More importantly, the mutant AAVrh.10 vector was able to partially evade neutralizing antibodies (~27-64 fold) in pre-immunized animals. The development of an AAV vector system that can escape the circulating neutralizing antibodies in the host will substantially widen the scope of gene therapy applications in humans.
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Affiliation(s)
- Ruchita Selot
- Department of Biological Sciences and Bioengineering, Indian Institute of TechnologyKanpur, India
| | - Sathyathithan Arumugam
- Department of Biological Sciences and Bioengineering, Indian Institute of TechnologyKanpur, India
| | - Bertin Mary
- Department of Biological Sciences and Bioengineering, Indian Institute of TechnologyKanpur, India
| | - Sabna Cheemadan
- Department of Hematology and Centre for Stem Cell Research (CSCR), Christian Medical CollegeVellore, India
| | - Giridhara R. Jayandharan
- Department of Biological Sciences and Bioengineering, Indian Institute of TechnologyKanpur, India
- Department of Hematology and Centre for Stem Cell Research (CSCR), Christian Medical CollegeVellore, India
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Tse LV, Moller-Tank S, Asokan A. Strategies to circumvent humoral immunity to adeno-associated viral vectors. Expert Opin Biol Ther 2015; 15:845-55. [PMID: 25985812 DOI: 10.1517/14712598.2015.1035645] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
INTRODUCTION Recent success in gene therapy of certain monogenic diseases in the clinic has infused enthusiasm into the continued development of recombinant adeno-associated viral (AAV) vectors as next-generation biologics. However, progress in clinical trials has also highlighted the challenges posed by the host humoral immune response to AAV vectors. Specifically, while pre-existing neutralizing antibodies (NAbs) limit the cohort of eligible patients, NAb generation following treatment prevents vector re-dosing. AREAS COVERED In this review, we discuss a spectrum of complementary strategies that can help circumvent the host humoral immune response to AAV. EXPERT OPINION Specifically, we present a dual perspective, that is, vector versus host, and highlight the clinical attributes, potential caveats and limitations as well as complementarity associated with the various approaches.
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Affiliation(s)
- Longping V Tse
- University of North Carolina, Gene Therapy Center , CB#7352, Thurston Building, Chapel Hill, NC 27599 , USA
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10
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Hareendran S, Ramakrishna B, Jayandharan GR. Synergistic inhibition of PARP-1 and NF-κB signaling downregulates immune response against recombinant AAV2 vectors during hepatic gene therapy. Eur J Immunol 2015; 46:154-66. [PMID: 26443873 DOI: 10.1002/eji.201545867] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 09/04/2015] [Accepted: 09/30/2015] [Indexed: 02/02/2023]
Abstract
Host immune response remains a key obstacle to widespread application of adeno-associated virus (AAV) based gene therapy. Thus, targeted inhibition of the signaling pathways that trigger such immune responses will be beneficial. Previous studies have reported that DNA damage response proteins such as poly(ADP-ribose) polymerase-1 (PARP-1) negatively affect the integration of AAV in the host genome. However, the role of PARP-1 in regulating AAV transduction and the immune response against these vectors has not been elucidated. In this study, we demonstrate that repression of PARP-1 improves the transduction of single-stranded AAV vectors both in vitro (∼174%) and in vivo (two- to 3.4-fold). Inhibition of PARP-1, also significantly downregulated the expression of several proinflammatory and cytokine markers such as TLRs, ILs, NF-κB subunit proteins associated with the host innate response against self-complementary AAV2 vectors. The suppression of the inflammatory response targeted against these vectors was more effective upon combined inhibition of PARP-1 and NF-κB signaling. This strategy also effectively attenuated the AAV capsid-specific cytotoxic T-cell response, with minimal effect on vector transduction, as demonstrated in normal C57BL/6 and hemophilia B mice. These data suggest that targeting specific host cellular proteins could be useful to attenuate the immune barriers to AAV-mediated gene therapy.
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Affiliation(s)
- Sangeetha Hareendran
- Centre for Stem Cell Research, Christian Medical College, Vellore, Tamil Nadu, India
| | - Banumathi Ramakrishna
- Department of General Pathology, Christian Medical College, Vellore, Tamil Nadu, India
| | - Giridhara R Jayandharan
- Centre for Stem Cell Research, Christian Medical College, Vellore, Tamil Nadu, India.,Department of Hematology, Christian Medical College, Vellore, Tamil Nadu, India.,Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur, Uttar Pradesh, India
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Gabriel N, Samuel R, Jayandharan GR. Targeted delivery of AAV-transduced mesenchymal stromal cells to hepatic tissue forex vivogene therapy. J Tissue Eng Regen Med 2015; 11:1354-1364. [DOI: 10.1002/term.2034] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Revised: 03/02/2015] [Accepted: 04/21/2015] [Indexed: 12/13/2022]
Affiliation(s)
- Nishanth Gabriel
- Department of Haematology; Christian Medical College; Vellore Tamil Nadu India
| | - Rekha Samuel
- Centre for Stem Cell Research; Christian Medical College; Vellore Tamil Nadu India
| | - Giridhara R. Jayandharan
- Department of Haematology; Christian Medical College; Vellore Tamil Nadu India
- Department of Biological Sciences and Bioengineering; Indian Institute of Technology; Kanpur Uttar Pradesh India
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12
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B-Cell Depletion is Protective Against Anti-AAV Capsid Immune Response: A Human Subject Case Study. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2014; 1:S2329-0501(16)30100-0. [PMID: 25541616 PMCID: PMC4275004 DOI: 10.1038/mtm.2014.33] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Gene therapy strategies for congenital myopathies may require repeat administration of adeno-associated viral (AAV) vectors due to aspects of the clinical application, such as: (i) administration of doses below therapeutic efficacy in patients enrolled in early phase clinical trials; (ii) progressive reduction of the therapeutic gene expression over time as a result of increasing muscle mass in patients treated at a young age; and (iii) a possibly faster depletion of pathogenic myofibers in this patient population. Immune response triggered by the first vector administration, and to subsequent doses, represents a major obstacle for successful gene transfer in young patients. Anti-capsid and anti-transgene product related humoral and cell-mediated responses have been previously observed in all preclinical models and human subjects who received gene therapy or enzyme replacement therapy (ERT) for congenital myopathies. Immune responses may result in reduced efficacy of the gene transfer over time and/or may preclude for the possibility of re-administration of the same vector. In this study, we evaluated the immune response of a Pompe patient dosed with an AAV1-GAA vector after receiving Rituximab and Sirolimus to modulate reactions against ERT. A key finding of this single subject case report is the observation that B-cell ablation with rituximab prior to AAV vector exposure results in non-responsiveness to both capsid and transgene, therefore allowing the possibility of repeat administration in the future. This observation is significant for future gene therapy studies and establishes a clinically relevant approach to blocking immune responses to AAV vectors.
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Sen D, Gadkari RA, Sudha G, Gabriel N, Kumar YS, Selot R, Samuel R, Rajalingam S, Ramya V, Nair SC, Srinivasan N, Srivastava A, Jayandharan GR. Targeted modifications in adeno-associated virus serotype 8 capsid improves its hepatic gene transfer efficiency in vivo. Hum Gene Ther Methods 2013; 24:104-16. [PMID: 23442071 DOI: 10.1089/hgtb.2012.195] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Recombinant adeno-associated virus vectors based on serotype 8 (AAV8) have shown significant promise for liver-directed gene therapy. However, to overcome the vector dose dependent immunotoxicity seen with AAV8 vectors, it is important to develop better AAV8 vectors that provide enhanced gene expression at significantly low vector doses. Since it is known that AAV vectors during intracellular trafficking are targeted for destruction in the cytoplasm by the host-cellular kinase/ubiquitination/proteasomal machinery, we modified specific serine/threonine kinase or ubiquitination targets on the AAV8 capsid to augment its transduction efficiency. Point mutations at specific serine (S)/threonine (T)/lysine (K) residues were introduced in the AAV8 capsid at the positions equivalent to that of the effective AAV2 mutants, generated successfully earlier. Extensive structure analysis was carried out subsequently to evaluate the structural equivalence between the two serotypes. scAAV8 vectors with the wild-type (WT) and each one of the S/T→Alanine (A) or K-Arginine (R) mutant capsids were evaluated for their liver transduction efficiency in C57BL/6 mice in vivo. Two of the AAV8-S→A mutants (S279A and S671A), and a K137R mutant vector, demonstrated significantly higher enhanced green fluorescent protein (EGFP) transcript levels (~9- to 46-fold) in the liver compared to animals that received WT-AAV8 vectors alone. The best performing AAV8 mutant (K137R) vector also had significantly reduced ubiquitination of the viral capsid, reduced activation of markers of innate immune response, and a concomitant two-fold reduction in the levels of neutralizing antibody formation in comparison to WT-AAV8 vectors. Vector biodistribution studies revealed that the K137R mutant had a significantly higher and preferential transduction of the liver (106 vs. 7.7 vector copies/mouse diploid genome) when compared to WT-AAV8 vectors. To further study the utility of the K137R-AAV8 mutant in therapeutic gene transfer, we delivered human coagulation factor IX (h.FIX) under the control of liver-specific promoters (LP1 or hAAT) into C57BL/6 mice. The circulating levels of h.FIX:Ag were higher in all the K137R-AAV8 treated groups up to 8 weeks post-hepatic gene transfer. These studies demonstrate the feasibility of the use of this novel AAV8 vectors for potential gene therapy of hemophilia B.
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Affiliation(s)
- Dwaipayan Sen
- Department of Hematology, Christian Medical College, Vellore 632004, Tamil Nadu, India
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14
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Tellez J, Van Vliet K, Tseng YS, Finn JD, Tschernia N, Almeida-Porada G, Arruda VR, Agbandje-McKenna M, Porada CD. Characterization of naturally-occurring humoral immunity to AAV in sheep. PLoS One 2013; 8:e75142. [PMID: 24086458 PMCID: PMC3782463 DOI: 10.1371/journal.pone.0075142] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Accepted: 08/09/2013] [Indexed: 11/18/2022] Open
Abstract
AAV vectors have shown great promise for clinical gene therapy (GT), but pre-existing human immunity against the AAV capsid often limits transduction. Thus, testing promising AAV-based GT approaches in an animal model with similar pre-existing immunity could better predict clinical outcome. Sheep have long been used for basic biological and preclinical studies. Moreover, we have re-established a line of sheep with severe hemophilia A (HA). Given the impetus to use AAV-based GT to treat hemophilia, we characterized the pre-existing ovine humoral immunity to AAV. ELISA revealed naturally-occurring antibodies to AAV1, AAV2, AAV5, AAV6, AAV8, and AAV9. For AAV2, AAV8, and AAV9 these inhibit transduction in a luciferase-based neutralization assay. Epitope mapping identified peptides that were common to the capsids of all AAV serotypes tested (AAV2, AAV5, AAV8 and AAV9), with each animal harboring antibodies to unique and common capsid epitopes. Mapping using X-ray crystallographic AAV capsid structures demonstrated that these antibodies recognized both surface epitopes and epitopes located within regions of the capsid that are internal or buried in the capsid structure. These results suggest that sheep harbor endogenous AAV, which induces immunity to both intact capsid and to capsid epitopes presented following proteolysis during the course of infection. In conclusion, their clinically relevant physiology and the presence of naturally-occurring antibodies to multiple AAV serotypes collectively make sheep a unique model in which to study GT for HA, and other diseases, and develop strategies to circumvent the clinically important barrier of pre-existing AAV immunity.
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Affiliation(s)
- Joseph Tellez
- Department of Animal Biotechnology, University of Nevada, Reno, Nevada, United States of America
| | - Kim Van Vliet
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, Florida, United States of America
| | - Yu-Shan Tseng
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, Florida, United States of America
| | - Jonathan D. Finn
- University of Pennsylvania School of Medicine, the Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | - Nick Tschernia
- Department of Animal Biotechnology, University of Nevada, Reno, Nevada, United States of America
| | - Graça Almeida-Porada
- Wake Forest Institute for Regenerative Medicine, Winston-Salem, North Carolina, United States of America
| | - Valder R. Arruda
- University of Pennsylvania School of Medicine, the Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | - Mavis Agbandje-McKenna
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, Florida, United States of America
| | - Christopher D. Porada
- Wake Forest Institute for Regenerative Medicine, Winston-Salem, North Carolina, United States of America
- * E-mail:
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Hareendran S, Balakrishnan B, Sen D, Kumar S, Srivastava A, Jayandharan GR. Adeno-associated virus (AAV) vectors in gene therapy: immune challenges and strategies to circumvent them. Rev Med Virol 2013; 23:399-413. [DOI: 10.1002/rmv.1762] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Revised: 08/08/2013] [Accepted: 08/09/2013] [Indexed: 12/12/2022]
Affiliation(s)
- Sangeetha Hareendran
- Centre for Stem Cell Research; Christian Medical College; Vellore Tamil Nadu India
| | - Balaji Balakrishnan
- Department of Hematology; Christian Medical College; Vellore Tamil Nadu India
| | - Dwaipayan Sen
- Department of Hematology; Christian Medical College; Vellore Tamil Nadu India
| | - Sanjay Kumar
- Centre for Stem Cell Research; Christian Medical College; Vellore Tamil Nadu India
| | - Alok Srivastava
- Centre for Stem Cell Research; Christian Medical College; Vellore Tamil Nadu India
- Department of Hematology; Christian Medical College; Vellore Tamil Nadu India
| | - Giridhara R. Jayandharan
- Centre for Stem Cell Research; Christian Medical College; Vellore Tamil Nadu India
- Department of Hematology; Christian Medical College; Vellore Tamil Nadu India
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