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Spector LP, Tiffany M, Ferraro NM, Abell NS, Montgomery SB, Kay MA. Evaluating the Genomic Parameters Governing rAAV-Mediated Homologous Recombination. Mol Ther 2021; 29:1028-1046. [PMID: 33248247 PMCID: PMC7934627 DOI: 10.1016/j.ymthe.2020.11.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Revised: 10/16/2020] [Accepted: 11/18/2020] [Indexed: 12/26/2022] Open
Abstract
Recombinant adeno-associated virus (rAAV) vectors have the unique ability to promote targeted integration of transgenes via homologous recombination at specified genomic sites, reaching frequencies of 0.1%-1%. We studied genomic parameters that influence targeting efficiencies on a large scale. To do this, we generated more than 1,000 engineered, doxycycline-inducible target sites in the human HAP1 cell line and infected this polyclonal population with a library of AAV-DJ targeting vectors, with each carrying a unique barcode. The heterogeneity of barcode integration at each target site provided an assessment of targeting efficiency at that locus. We compared targeting efficiency with and without target site transcription for identical chromosomal positions. Targeting efficiency was enhanced by target site transcription, while chromatin accessibility was associated with an increased likelihood of targeting. ChromHMM chromatin states characterizing transcription and enhancers in wild-type K562 cells were also associated with increased AAV-HR efficiency with and without target site transcription, respectively. Furthermore, the amenability of a site to targeting was influenced by the endogenous transcriptional level of intersecting genes. These results define important parameters that may not only assist in designing optimal targeting vectors for genome editing, but also provide new insights into the mechanism of AAV-mediated homologous recombination.
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Affiliation(s)
- Laura P Spector
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Matthew Tiffany
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA; Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA
| | - Nicole M Ferraro
- Biomedical Informatics Program, Stanford University School of Medicine, Stanford, CA, USA
| | - Nathan S Abell
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Stephen B Montgomery
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA; Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA
| | - Mark A Kay
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA; Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA.
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2
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Chen HM, Resendes R, Ghodssi A, Sookiasian D, Tian M, Dollive S, Adamson-Small L, Avila N, Tazearslan C, Thompson JF, Ellsworth JL, Francone O, Seymour A, Wright JB. Molecular characterization of precise in vivo targeted gene integration in human cells using AAVHSC15. PLoS One 2020; 15:e0233373. [PMID: 32453743 PMCID: PMC7250422 DOI: 10.1371/journal.pone.0233373] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 05/04/2020] [Indexed: 02/08/2023] Open
Abstract
Targeted gene integration via precise homologous recombination (HR)-based gene editing has the potential to correct genetic diseases. AAV (adeno-associated virus) can mediate nuclease-free gene integration at a disease-causing locus. Therapeutic application of AAV gene integration requires quantitative molecular characterization of the edited sequence that overcome technical obstacles such as excess episomal vector genomes and lengthy homology arms. Here we describe a novel molecular methodology that utilizes quantitative next-generation sequencing to characterize AAV-mediated targeted insertion and detects the presence of unintended mutations. The methods described here quantify targeted insertion and query the entirety of the target locus for the presence of insertions, deletions, single nucleotide variants (SNVs) and integration of viral components such as inverted terminal repeats (ITR). Using a humanized liver murine model, we demonstrate that hematopoietic stem-cell derived AAVHSC15 mediates in vivo targeted gene integration into human chromosome 12 at the PAH (phenylalanine hydroxylase) locus at 6% frequency, with no sign of co-incident random mutations at or above a lower limit of detection of 0.5% and no ITR sequences at the integration sites. Furthermore, analysis of heterozygous variants across the targeted locus using the methods described shows a pattern of strand cross-over, supportive of an HR mechanism of gene integration with similar efficiencies across two different haplotypes. Rapid advances in the application of AAV-mediated nuclease-free target integration, or gene editing, as a new therapeutic modality requires precise understanding of the efficiency and the nature of the changes being introduced to the target genome at the molecular level. This work provides a framework to be applied to homologous recombination gene editing platforms for assessment of introduced and natural sequence variation across a target site.
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Affiliation(s)
- Huei-Mei Chen
- Homology Medicines Inc., Bedford, Massachusetts, United States of America
| | - Rachel Resendes
- Homology Medicines Inc., Bedford, Massachusetts, United States of America
| | - Azita Ghodssi
- Homology Medicines Inc., Bedford, Massachusetts, United States of America
| | | | - Michael Tian
- Homology Medicines Inc., Bedford, Massachusetts, United States of America
| | - Serena Dollive
- Homology Medicines Inc., Bedford, Massachusetts, United States of America
| | | | - Nancy Avila
- Homology Medicines Inc., Bedford, Massachusetts, United States of America
| | - Cagdas Tazearslan
- Homology Medicines Inc., Bedford, Massachusetts, United States of America
| | - John F. Thompson
- Homology Medicines Inc., Bedford, Massachusetts, United States of America
| | - Jeff L. Ellsworth
- Homology Medicines Inc., Bedford, Massachusetts, United States of America
| | - Omar Francone
- Homology Medicines Inc., Bedford, Massachusetts, United States of America
| | - Albert Seymour
- Homology Medicines Inc., Bedford, Massachusetts, United States of America
| | - Jason B. Wright
- Homology Medicines Inc., Bedford, Massachusetts, United States of America
- * E-mail:
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3
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Tan L, Hu Y, Li Y, Yang L, Cai X, Liu W, He J, Wu Y, Liu T, Wang N, Yang Y, Adelstein RS, Wang A. Investigation of the molecular biology underlying the pronounced high gene targeting frequency at the Myh9 gene locus in mouse embryonic stem cells. PLoS One 2020; 15:e0230126. [PMID: 32226034 PMCID: PMC7105122 DOI: 10.1371/journal.pone.0230126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 02/23/2020] [Indexed: 11/21/2022] Open
Abstract
The generation of genetically modified mouse models derived from gene targeting (GT) in mouse embryonic stem (ES) cells (mESCs) has greatly advanced both basic and clinical research. Our previous finding that gene targeting at the Myh9 exon2 site in mESCs has a pronounced high homologous recombination (HR) efficiency (>90%) has facilitated the generation of a series of nonmuscle myosin II (NM II) related mouse models. Furthermore, the Myh9 gene locus has been well demonstrated to be a new safe harbor for site-specific insertion of other exogenous genes. In the current study, we intend to investigate the molecular biology underlying for this high HR efficiency from other aspects. Our results confirmed some previously characterized properties and revealed some unreported observations: 1) The comparison and analysis of the targeting events occurring at the Myh9 and several widely used loci for targeting transgenesis, including ColA1, HPRT, ROSA26, and the sequences utilized for generating these targeting constructs, indicated that a total length about 6 kb with approximate 50% GC-content of the 5’ and 3’ homologous arms, may facilitate a better performance in terms of GT efficiency. 2) Despite increasing the length of the homologous arms, shifting the targeting site from the Myh9 exon2, to intron2, or exon3 led to a gradually reduced GT frequency (91.7, 71.8 and 50.0%, respectively). This finding provides the first evidence that the HR frequency may also be associated with the targeting site even in the same locus. Meanwhile, the decreased trend of the GT efficiency at these targeting sites was consistent with the reduced percentage of simple sequence repeat (SSR) and short interspersed nuclear elements (SINEs) in the sequences for generating the targeting constructs, suggesting the potential effects of these DNA elements on GT efficiency; 3) Our series of targeting experiments and analyses with truncated 5’ and 3’ arms at the Myh9 exon2 site demonstrated that GT efficiency positively correlates with the total length of the homologous arms (R = 0.7256, p<0.01), confirmed that a 2:1 ratio of the length, a 50% GC-content and the higher amount of SINEs for the 5’ and 3’ arms may benefit for appreciable GT frequency. Though more investigations are required, the Myh9 gene locus appears to be an ideal location for identifying HR-related cis and trans factors, which in turn provide mechanistic insights and also facilitate the practical application of gene editing.
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Affiliation(s)
- Lei Tan
- Laboratory of Animal Disease Prevention & Control and Animal Model, The Key Laboratory of Animal Vaccine & Protein Engineering, College of Veterinary Medicine, Hunan Agricultural University (HUNAU), Changsha, Hunan, China
| | - Yi Hu
- Laboratory of Animal Disease Prevention & Control and Animal Model, The Key Laboratory of Animal Vaccine & Protein Engineering, College of Veterinary Medicine, Hunan Agricultural University (HUNAU), Changsha, Hunan, China
| | - Yalan Li
- Laboratory of Animal Disease Prevention & Control and Animal Model, The Key Laboratory of Animal Vaccine & Protein Engineering, College of Veterinary Medicine, Hunan Agricultural University (HUNAU), Changsha, Hunan, China
| | - Lingchen Yang
- Laboratory of Animal Disease Prevention & Control and Animal Model, The Key Laboratory of Animal Vaccine & Protein Engineering, College of Veterinary Medicine, Hunan Agricultural University (HUNAU), Changsha, Hunan, China
| | - Xiong Cai
- Institute of Innovation and Applied Research in Chinese Medicine, Hunan University of Chinese Medicine, Changsha, Hunan, China
| | - Wei Liu
- Laboratory of Animal Disease Prevention & Control and Animal Model, The Key Laboratory of Animal Vaccine & Protein Engineering, College of Veterinary Medicine, Hunan Agricultural University (HUNAU), Changsha, Hunan, China
| | - Jiayi He
- Laboratory of Animal Disease Prevention & Control and Animal Model, The Key Laboratory of Animal Vaccine & Protein Engineering, College of Veterinary Medicine, Hunan Agricultural University (HUNAU), Changsha, Hunan, China
| | - Yingxin Wu
- Laboratory of Animal Disease Prevention & Control and Animal Model, The Key Laboratory of Animal Vaccine & Protein Engineering, College of Veterinary Medicine, Hunan Agricultural University (HUNAU), Changsha, Hunan, China
| | - Tanbin Liu
- Laboratory of Animal Disease Prevention & Control and Animal Model, The Key Laboratory of Animal Vaccine & Protein Engineering, College of Veterinary Medicine, Hunan Agricultural University (HUNAU), Changsha, Hunan, China
| | - Naidong Wang
- Laboratory of Functional Proteomics (LFP), The Key Laboratory of Animal Vaccine & Protein Engineering, College of Veterinary Medicine, HUNAU, Changsha, Hunan, China
| | - Yi Yang
- Laboratory of Functional Proteomics (LFP), The Key Laboratory of Animal Vaccine & Protein Engineering, College of Veterinary Medicine, HUNAU, Changsha, Hunan, China
| | - Robert S. Adelstein
- Laboratory of Molecular Cardiology (LMC), NHLBI/NIH, Bethesda, MD, United States of America
| | - Aibing Wang
- Laboratory of Animal Disease Prevention & Control and Animal Model, The Key Laboratory of Animal Vaccine & Protein Engineering, College of Veterinary Medicine, Hunan Agricultural University (HUNAU), Changsha, Hunan, China
- Laboratory of Molecular Cardiology (LMC), NHLBI/NIH, Bethesda, MD, United States of America
- * E-mail:
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4
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Gravells P, Ahrabi S, Vangala RK, Tomita K, Brash JT, Brustle LA, Chung C, Hong JM, Kaloudi A, Humphrey TC, Porter ACG. Use of the HPRT gene to study nuclease-induced DNA double-strand break repair. Hum Mol Genet 2015; 24:7097-110. [PMID: 26423459 PMCID: PMC4654060 DOI: 10.1093/hmg/ddv409] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 09/23/2015] [Indexed: 12/17/2022] Open
Abstract
Understanding the mechanisms of chromosomal double-strand break repair (DSBR) provides insight into genome instability, oncogenesis and genome engineering, including disease gene correction. Research into DSBR exploits rare-cutting endonucleases to cleave exogenous reporter constructs integrated into the genome. Multiple reporter constructs have been developed to detect various DSBR pathways. Here, using a single endogenous reporter gene, the X-chromosomal disease gene encoding hypoxanthine phosphoribosyltransferase (HPRT), we monitor the relative utilization of three DSBR pathways following cleavage by I-SceI or CRISPR/Cas9 nucleases. For I-SceI, our estimated frequencies of accurate or mutagenic non-homologous end-joining and gene correction by homologous recombination are 4.1, 1.5 and 0.16%, respectively. Unexpectedly, I-SceI and Cas9 induced markedly different DSBR profiles. Also, using an I-SceI-sensitive HPRT minigene, we show that gene correction is more efficient when using long double-stranded DNA than single- or double-stranded oligonucleotides. Finally, using both endogenous HPRT and exogenous reporters, we validate novel cell cycle phase-specific I-SceI derivatives for investigating cell cycle variations in DSBR. The results obtained using these novel approaches provide new insights into template design for gene correction and the relationships between multiple DSBR pathways at a single endogenous disease gene.
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Affiliation(s)
- Polly Gravells
- Gene Targeting Group, Centre for Haematology, Imperial College Faculty of Medicine, London W120NN, UK and
| | - Sara Ahrabi
- CRUK MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford OX3 7DQ, UK
| | - Rajani K Vangala
- Gene Targeting Group, Centre for Haematology, Imperial College Faculty of Medicine, London W120NN, UK and
| | - Kazunori Tomita
- Gene Targeting Group, Centre for Haematology, Imperial College Faculty of Medicine, London W120NN, UK and
| | - James T Brash
- Gene Targeting Group, Centre for Haematology, Imperial College Faculty of Medicine, London W120NN, UK and
| | - Lena A Brustle
- Gene Targeting Group, Centre for Haematology, Imperial College Faculty of Medicine, London W120NN, UK and
| | - Christopher Chung
- Gene Targeting Group, Centre for Haematology, Imperial College Faculty of Medicine, London W120NN, UK and
| | - Julia M Hong
- Gene Targeting Group, Centre for Haematology, Imperial College Faculty of Medicine, London W120NN, UK and
| | - Aikaterini Kaloudi
- Gene Targeting Group, Centre for Haematology, Imperial College Faculty of Medicine, London W120NN, UK and
| | - Timothy C Humphrey
- CRUK MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford OX3 7DQ, UK
| | - Andrew C G Porter
- Gene Targeting Group, Centre for Haematology, Imperial College Faculty of Medicine, London W120NN, UK and
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5
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Genome Engineering Using Adeno-associated Virus: Basic and Clinical Research Applications. Mol Ther 2015; 24:458-64. [PMID: 26373345 DOI: 10.1038/mt.2015.151] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2015] [Accepted: 07/21/2015] [Indexed: 12/18/2022] Open
Abstract
In addition to their broad potential for therapeutic gene delivery, adeno-associated virus (AAV) vectors possess the innate ability to stimulate homologous recombination in mammalian cells at high efficiencies. This process--referred to as AAV-mediated gene targeting--has enabled the introduction of a diverse array of genomic modifications both in vitro and in vivo. With the recent emergence of targeted nucleases, AAV-mediated genome engineering is poised for clinical translation. Here, we review key properties of AAV vectors that underscore its unique utility in genome editing. We highlight the broad range of genome engineering applications facilitated by this technology and discuss the strong potential for unifying AAV with targeted nucleases for next-generation gene therapy.
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6
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Alexander IE, Russell DW. The Potential of AAV-Mediated Gene Targeting for Gene and Cell Therapy Applications. CURRENT STEM CELL REPORTS 2015. [DOI: 10.1007/s40778-014-0001-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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7
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Deyle DR, Hansen RS, Cornea AM, Li LB, Burt AA, Alexander IE, Sandstrom RS, Stamatoyannopoulos JA, Wei CL, Russell DW. A genome-wide map of adeno-associated virus-mediated human gene targeting. Nat Struct Mol Biol 2014; 21:969-75. [PMID: 25282150 PMCID: PMC4405182 DOI: 10.1038/nsmb.2895] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Accepted: 08/27/2014] [Indexed: 02/03/2023]
Abstract
To determine which genomic features promote homologous recombination, we created a genome-wide map of gene targeting sites. We used an adeno-associated virus vector to target identical loci introduced as transcriptionally active retroviral vectors. A comparison of ~2,000 targeted and untargeted sites showed that targeting occurred throughout the human genome and was not influenced by the presence of nearby CpG islands, sequence repeats or DNase I-hypersensitive sites. Targeted sites were preferentially located within transcription units, especially when the target loci were transcribed in the opposite orientation to their surrounding chromosomal genes. We determined the impact of DNA replication by mapping replication forks, which revealed a preference for recombination at target loci transcribed toward an incoming fork. Our results constitute the first genome-wide screen of gene targeting in mammalian cells and demonstrate a strong recombinogenic effect of colliding polymerases.
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Affiliation(s)
- David R Deyle
- Department of Medicine, University of Washington, Seattle, Washington, USA
| | - R Scott Hansen
- Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Anda M Cornea
- Department of Molecular and Cellular Biology, University of Washington, Seattle, Washington, USA
| | - Li B Li
- Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Amber A Burt
- Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Ian E Alexander
- Gene Therapy Research Unit, Children's Medical Research Institute, Westmead, New South Wales, Australia
| | - Richard S Sandstrom
- Department of Genome Sciences, University of Washington, Seattle, Washington, USA
| | | | - Chia-Lin Wei
- Genomic Technologies Department, Joint Genome Institute, Walnut Creek, California, USA
| | - David W Russell
- 1] Department of Medicine, University of Washington, Seattle, Washington, USA. [2] Department of Biochemistry, University of Washington, Seattle, Washington, USA
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8
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Metzger MJ, Certo MT. Design and analysis of site-specific single-strand nicking endonucleases for gene correction. Methods Mol Biol 2014; 1114:237-44. [PMID: 24557907 DOI: 10.1007/978-1-62703-761-7_15] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023]
Abstract
Single-strand nicking endonucleases ("nickases") have been shown to induce homology-mediated gene correction with reduced toxicity of DNA double-strand break-producing enzymes, and nickases have been engineered from both homing endonuclease and FokI-based scaffolds. We describe the strategies used to engineer these site-specific nickases as well as the in vitro methods used to confirm their activity and specificity. Additionally, we describe the Traffic Light Reporter system, which uses a flow cytometric assay to simultaneously detect both gene repair and mutagenic nonhomologous end-joining outcomes at a single targeted site in mammalian cells. With these methods, novel nickases can be designed and tested for use in gene correction with novel target sites.
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Affiliation(s)
- Michael J Metzger
- Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
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9
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Deyle DR, Li LB, Ren G, Russell DW. The effects of polymorphisms on human gene targeting. Nucleic Acids Res 2013; 42:3119-24. [PMID: 24371280 PMCID: PMC3950700 DOI: 10.1093/nar/gkt1303] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
DNA mismatches that occur between vector homology arms and chromosomal target sequences reduce gene targeting frequencies in several species; however, this has not been reported in human cells. Here we demonstrate that even a single mismatched base pair can significantly decrease human gene targeting frequencies. In addition, we show that homology arm polymorphisms can be used to direct allele-specific targeting or to improve unfavorable vector designs that introduce deletions.
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Affiliation(s)
- David R Deyle
- Department of Medicine, University of Washington, Seattle, WA, 98195, USA and Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA
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Colosimo A, Curini V, Russo V, Mauro A, Bernabò N, Marchisio M, Alfonsi M, Muttini A, Mattioli M, Barboni B. Characterization, GFP gene Nucleofection, and allotransplantation in injured tendons of ovine amniotic fluid-derived stem cells. Cell Transplant 2012; 22:99-117. [PMID: 22507078 DOI: 10.3727/096368912x638883] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Amniotic fluid has drawn increasing attention in the recent past as a cost-effective and accessible source of fetal stem cells. Amniotic fluid-derived mesenchymal stem cells (AFMSCs) that display high proliferation rate, large spectrum of differentiation potential, and immunosuppressive features are considered optimal candidates for allogeneic repair of mesenchymal damaged tissues. In this study, ovine AFMSCs (oAFMSCs) isolated from 3-month-old sheep fetuses were characterized for their proliferation rate, specific surface antigen and pluripotency marker expression, genomic stability, and mesenchymal lineage differentiation during their in vitro expansion (12 passages) and after nucleofection. The high proliferation rate of oAFMSCs gradually decreased during the first six subculture passages while the expression of surface molecules (CD29, CD58, CD166) and of pluripotency-associated markers (OCT4, TERT, NANOG, SOX2), the in vitro osteogenic differentiation potential, and a normal karyotype were maintained. Afterwards, oAFMSCs were nucleofected with a selectable plasmid coding for green fluorescent protein (GFP) using two different programs, U23 and C17, previously optimized for human mesenchymal stem cells. Transfection efficiencies were ∼63% and ∼37%, while cell recoveries were ∼10% and ∼22%, respectively. Nucleofected oAFMSCs expressing the GFP transgene conserved their pluripotency marker profile and retained a normal karyotype and the osteogenic differentiation ability. Seven single clones with a GFP expression ranging from 80% to 97% were then isolated and expanded over 1 month, thus providing stably transfected cells with long-term therapeutic potential. The in vivo behavior of GFP-labeled oAFMSCs was tested on a previously validated preclinical model of experimentally induced Achille's tendon defect. The allotransplanted oAFMSCs were able to survive within the host tissue for 1 month enhancing the early phase of tendon healing as indicated by morphological and biomechanical results. Altogether these data suggest that genetically modified oAFMSCs might represent a valuable tool for in vivo preclinical studies in a highly valid translational model.
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Affiliation(s)
- A Colosimo
- Department of Comparative Biomedical Sciences, University of Teramo, Italy.
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