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Functional analysis of the catalytic triad of the hAT-family transposase TcBuster. Plasmid 2021; 114:102554. [PMID: 33476638 DOI: 10.1016/j.plasmid.2021.102554] [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: 09/29/2020] [Revised: 11/16/2020] [Accepted: 11/25/2020] [Indexed: 11/23/2022]
Abstract
TcBuster is a hAT-family DNA transposon from the red flour beetle, Tribolium castaneum. The TcBuster transposase is of interest for genome engineering as it is highly active in insect and mammalian cells. To test the predicted catalytic triad of TcBuster, each residue of the catalytic triad of a haemagglutinin-tagged TcBuster transposase was individually mutated to a structurally conserved amino acid. Using a drug-resistant colony assay for transposon integration, we found that the D223N, D289N, and E589Q mutants of TcBuster transposase were inactive in human cells. We used a modified chromatin immunoprecipitation assay to determine that each mutant maintained binding to TcBuster transposon inverted repeat elements. Although the catalytic mutants retained their transposon binding properties, mutants displayed altered expression and localization in human cells. None of the catalytic mutants formed characteristic TcBuster transposase rodlet structures, and the D223N and D289N mutants were not able to be detected by immunofluorescence microscopy. Immunoblot analysis demonstrated that the E589Q mutant is less abundant than wild-type TcBuster transposase. Cells transfected with either TcBuster or TcBuster-E589Q transposase were imaged by structured illumination microscopy to quantify differences in the length of the transposase rodlets. The average length of the TcBuster transposase rodlets (N = 39) was 3.284 μm while the E589Q rodlets (N = 33) averaged 1.157 μm (p < 0.0001; t-test). The catalytic triad mutations decreased overall protein levels and disrupted transposase rodlet formation while nuclear localization and DNA binding to the inverted repeat elements were maintained. Our results may have broader implications for the overproduction inhibition phenomenon observed for DNA transposons.
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Wilson MH, Veach RA, Luo W, Welch RC, Roy S, Fissell WH. Genome Engineering Renal Epithelial Cells for Enhanced Volume Transport Function. Cell Mol Bioeng 2019; 13:17-26. [PMID: 32030105 DOI: 10.1007/s12195-019-00601-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Accepted: 09/14/2019] [Indexed: 12/20/2022] Open
Abstract
Introduction Bioengineering an implantable artificial kidney (IAK) will require renal epithelial cells capable of reabsorption of salt and water. We used genome engineering to modify cells for improved Na+/H+ exchange and H2O reabsorption. The non-viral piggyBac transposon system enables genome engineering cells to stably overexpress one or more transgenes simultaneously. Methods We generated epitope-tagged human sodium hydrogen exchanger 3 (NHE3) and aquaporin-1 (AQP1) cDNA expressing piggyBac transposon vectors. Transgene expression was evaluated via western blot and immunofluorescence. Flow cytometry analysis was used to quantitate transporter expression in a library of genome engineered clones. Cell surface biotinylation was used evaluate surface protein localization. Blister formation assays were used to monitor cellular volumetric transport. Results piggyBac enabled stable transposon integration and overexpression of cumate-inducible NHE3 and/or constitutively expressing AQP1 in cultured renal (MDCK) epithelial cells. Cell surface delivery of NHE3 and AQP1 was confirmed using cell surface biotinylation assays. Flow cytometry of a library of MDCK clones revealed varying expression of AQP1 and NHE3. MDCK cells expressing AQP1 and cumate-inducible NHE3 demonstrated increased volumetric transport. Conclusions Our results demonstrate that renal epithelial cells an be genome engineered for enhanced volumetric transport that will be needed for an IAK device. Our results lay the foundation for future studies of genome engineering human kidney cells for renal tubule cell therapy.
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Affiliation(s)
- Matthew H Wilson
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center, 1161 21st Ave South, S-3223 MCN, Nashville, TN 37232 USA
- Department of Veterans Affairs, Tennessee Valley Health Services, Nashville, TN 37212 USA
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232 USA
| | - Ruth Ann Veach
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center, 1161 21st Ave South, S-3223 MCN, Nashville, TN 37232 USA
| | - Wentian Luo
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center, 1161 21st Ave South, S-3223 MCN, Nashville, TN 37232 USA
| | - Richard C Welch
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center, 1161 21st Ave South, S-3223 MCN, Nashville, TN 37232 USA
| | - Shuvo Roy
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, CA 94158 USA
| | - William H Fissell
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center, 1161 21st Ave South, S-3223 MCN, Nashville, TN 37232 USA
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN 37232 USA
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O'Neil RT, Saha S, Veach RA, Welch RC, Woodard LE, Rooney CM, Wilson MH. Transposon-modified antigen-specific T lymphocytes for sustained therapeutic protein delivery in vivo. Nat Commun 2018; 9:1325. [PMID: 29636469 PMCID: PMC5893599 DOI: 10.1038/s41467-018-03787-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 03/12/2018] [Indexed: 12/22/2022] Open
Abstract
A cell therapy platform permitting long-term delivery of peptide hormones in vivo would be a significant advance for patients with hormonal deficiencies. Here we report the utility of antigen-specific T lymphocytes as a regulatable peptide delivery platform for in vivo therapy. piggyBac transposon modification of murine cells with luciferase allows us to visualize T cells after adoptive transfer. Vaccination stimulates long-term T-cell engraftment, persistence, and transgene expression enabling detection of modified cells up to 300 days after adoptive transfer. We demonstrate adoptive transfer of antigen-specific T cells expressing erythropoietin (EPO) elevating the hematocrit in mice for more than 20 weeks. We extend our observations to human T cells demonstrating inducible EPO production from Epstein-Barr virus (EBV) antigen-specific T lymphocytes. Our results reveal antigen-specific T lymphocytes to be an effective delivery platform for therapeutic molecules such as EPO in vivo, with important implications for other diseases that require peptide therapy.
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Affiliation(s)
- Richard T O'Neil
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
- The Vanderbilt Center for Kidney Disease, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
| | - Sunandan Saha
- Interdepartmental Program in Translational Biology and Molecular Medicine, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Ruth Ann Veach
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
- The Vanderbilt Center for Kidney Disease, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
| | - Richard C Welch
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
- The Vanderbilt Center for Kidney Disease, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
| | - Lauren E Woodard
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
- The Vanderbilt Center for Kidney Disease, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
- Department of Veterans Affairs, Nashville, TN, 37212, USA
| | - Cliona M Rooney
- Center for Cell and Gene Therapy, Baylor College of Medicine, Houston, TX, 77030, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA
- Department of Immunology, Baylor College of Medicine, Houston, TX, 77030, USA
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Matthew H Wilson
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA.
- The Vanderbilt Center for Kidney Disease, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA.
- Department of Veterans Affairs, Nashville, TN, 37212, USA.
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Woodard LE, Cheng J, Welch RC, Williams FM, Luo W, Gewin LS, Wilson MH. Kidney-specific transposon-mediated gene transfer in vivo. Sci Rep 2017; 7:44904. [PMID: 28317878 PMCID: PMC5357952 DOI: 10.1038/srep44904] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 02/14/2017] [Indexed: 12/18/2022] Open
Abstract
Methods enabling kidney-specific gene transfer in adult mice are needed to develop new therapies for kidney disease. We attempted kidney-specific gene transfer following hydrodynamic tail vein injection using the kidney-specific podocin and gamma-glutamyl transferase promoters, but found expression primarily in the liver. In order to achieve kidney-specific transgene expression, we tested direct hydrodynamic injection of a DNA solution into the renal pelvis and found that luciferase expression was strong in the kidney and absent from extra-renal tissues. We observed heterogeneous, low-level transfection of the collecting duct, proximal tubule, distal tubule, interstitial cells, and rarely glomerular cells following injection. To assess renal injury, we performed the renal pelvis injections on uninephrectomised mice and found that their blood urea nitrogen was elevated at two days post-transfer but resolved within two weeks. Although luciferase expression quickly decreased following renal pelvis injection, the use of the piggyBac transposon system improved long-term expression. Immunosuppression with cyclophosphamide stabilised luciferase expression, suggesting immune clearance of the transfected cells occurs in immunocompetent animals. Injection of a transposon expressing erythropoietin raised the haematocrit, indicating that the developed injection technique can elicit a biologic effect in vivo. Hydrodynamic renal pelvis injection enables transposon mediated-kidney specific gene transfer in adult mice.
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Affiliation(s)
- Lauren E Woodard
- Department of Veterans Affairs, Nashville, TN 37212 USA.,Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232 USA.,Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jizhong Cheng
- Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA
| | - Richard C Welch
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232 USA
| | - Felisha M Williams
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232 USA
| | - Wentian Luo
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232 USA
| | - Leslie S Gewin
- Department of Veterans Affairs, Nashville, TN 37212 USA.,Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232 USA.,Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232 USA
| | - Matthew H Wilson
- Department of Veterans Affairs, Nashville, TN 37212 USA.,Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232 USA.,Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA.,Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232 USA.,Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232 USA.,Department of Veterans Affairs, Houston, TX 77030 USA
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Woodard LE, Downes LM, Lee YC, Kaja A, Terefe ES, Wilson MH. Temporal self-regulation of transposition through host-independent transposase rodlet formation. Nucleic Acids Res 2016; 45:353-366. [PMID: 27899587 PMCID: PMC5224482 DOI: 10.1093/nar/gkw1115] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Revised: 10/25/2016] [Accepted: 10/27/2016] [Indexed: 11/12/2022] Open
Abstract
Transposons are highly abundant in eukaryotic genomes, but their mobilization must be finely tuned to maintain host organism fitness and allow for transposon propagation. Forty percent of the human genome is comprised of transposable element sequences, and the most abundant cut-and-paste transposons are from the hAT superfamily. We found that the hAT transposase TcBuster from Tribolium castaneum formed filamentous structures, or rodlets, in human tissue culture cells, after gene transfer to adult mice, and ex vivo in cell-free conditions, indicating that host co-factors or cellular structures were not required for rodlet formation. Time-lapsed imaging of GFP-laced rodlets in human cells revealed that they formed quickly in a dynamic process involving fusion and fission. We delayed the availability of the transposon DNA and found that transposition declined after transposase concentrations became high enough for visible transposase rodlets to appear. In combination with earlier findings for maize Ac elements, these results give insight into transposase overproduction inhibition by demonstrating that the appearance of transposase protein structures and the end of active transposition are simultaneous, an effect with implications for genetic engineering and horizontal gene transfer.
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Affiliation(s)
- Lauren E Woodard
- Department of Veterans Affairs, Nashville, TN 37212, USA and Department of Medicine, Vanderbilt University, Nashville, TN 37232, USA.,Department of Veterans Affairs, Houston, TX 77030, USA and Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA
| | - Laura M Downes
- Department of Veterans Affairs, Nashville, TN 37212, USA and Department of Medicine, Vanderbilt University, Nashville, TN 37232, USA
| | - Yi-Chien Lee
- Department of Veterans Affairs, Houston, TX 77030, USA and Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA
| | - Aparna Kaja
- Department of Veterans Affairs, Houston, TX 77030, USA and Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA
| | - Eyuel S Terefe
- Department of Veterans Affairs, Houston, TX 77030, USA and Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA
| | - Matthew H Wilson
- Department of Veterans Affairs, Nashville, TN 37212, USA and Department of Medicine, Vanderbilt University, Nashville, TN 37232, USA .,Department of Veterans Affairs, Houston, TX 77030, USA and Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA
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Di Matteo M, Samara-Kuko E, Ward NJ, Waddington SN, Waddingon SN, McVey JH, Chuah MKL, VandenDriessche T. Hyperactive piggyBac transposons for sustained and robust liver-targeted gene therapy. Mol Ther 2014; 22:1614-24. [PMID: 25034357 PMCID: PMC4435487 DOI: 10.1038/mt.2014.131] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Accepted: 06/27/2014] [Indexed: 01/14/2023] Open
Abstract
The development of robust nonviral vectors could facilitate clinical gene therapy applications and may overcome some of the immune complications of viral vectors. Nevertheless, most nonviral gene deliver approaches typically yield only transient and/or low gene expression. To address these caveats, we have explored piggyBac transposons to correct hemophilia B by liver-directed factor IX (FIX) gene therapy in hemophilic mice. To achieve this, we combined the use of: (i) a hyperactive codon-optimized piggyBac transposase, (ii) a computationally enhanced liver-specific promoter, (iii) a hyperfunctional codon-optimized FIX transgene (FIX R338L Padua), and (iv) a modification of the transposon terminal repeats. This combination strategy resulted in a robust 400-fold improvement in vector performance in hepatocytes, yielding stable supraphysiologic human FIX activity (>1 year). Liver-specific expression resulted in the induction of FIX-specific immune tolerance. Remarkably, only very low transposon/transposase doses were required to cure the bleeding diathesis. Similarly, PB transposons could be used to express supraphysiologic factor VIII levels using low transposon/transposase doses. PB transposition did not induce tumors in a sensitive hepatocellular carcinoma-prone mouse model. These results underscore the potency and relative safety of the latest generation PB transposons, which constitutes a versatile platform for stable and robust secretion of therapeutic proteins.
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Affiliation(s)
- Mario Di Matteo
- 1] Department of Gene Therapy and Regenerative Medicine, Free University of Brussels, Brussels, Belgium [2] Center for Molecular and Vascular Biology, Department of Cardiovascular Medicine, University of Leuven, Leuven, Belgium
| | - Emira Samara-Kuko
- Department of Gene Therapy and Regenerative Medicine, Free University of Brussels, Brussels, Belgium
| | - Natalie J Ward
- Molecular Immunology Unit, Institute of Child Health, University College London, London, UK
| | - Simon N Waddington
- 1] Institute for Women's Health Gene Transfer Technology Group, University College London, London, UK [2] School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, South Africa
| | | | - John H McVey
- University of Surrey, Molecular Medicine Group, Surrey, UK
| | - Marinee K L Chuah
- 1] Department of Gene Therapy and Regenerative Medicine, Free University of Brussels, Brussels, Belgium [2] Center for Molecular and Vascular Biology, Department of Cardiovascular Medicine, University of Leuven, Leuven, Belgium
| | - Thierry VandenDriessche
- 1] Department of Gene Therapy and Regenerative Medicine, Free University of Brussels, Brussels, Belgium [2] Center for Molecular and Vascular Biology, Department of Cardiovascular Medicine, University of Leuven, Leuven, Belgium
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