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Improvement of the recombinant human coagulation factor IX expression by co-expression of a novel transcript of Drosophila γ carboxylase in a human cell line. Biotechnol Lett 2020; 42:2147-2156. [PMID: 32514789 DOI: 10.1007/s10529-020-02936-8] [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: 10/26/2019] [Accepted: 06/01/2020] [Indexed: 10/24/2022]
Abstract
OBJECTIVE Mammalian cells as the main host for production of human proteins are incapable of complete γ-carboxylation of over-expressed Vitamin K Dependent (VKD) proteins. The Drosophila γ-glutamyl carboxylase (DγC) has been shown to be more efficient than its human counterpart in γ-carboxylation of human substrates, in vitro. Considering the Drosophila γ-carboxylase (DγC) efficiency, in comparison with its human counterpart, for recognition and γ-carboxylation of a human substrate in vitro, we were determined to study the effect of the DγC on the hFIX expression in a mammalian cell line. With this aim, we examined co-expression of the DγC with the hFIX, in a human cell line. RESULTS While the co-expression of a complete DγC cDNA reduced the hFIX expression, a truncated form of DγC could improve both the expression level (up to 1211 ng/106 cells/ml on the 4th day of post-transfection) and carboxylation of the expressed hFIX, significantly (p < 0.009). CONCLUSIONS Our findings provided evidences for potential of a partial fragment of the DγC for improvement of the γ-carboxylation of a human substrate in a mammalian cell. Our experimental data, in accordance with in silico analysis suggested that the DγC C-terminal fragment, with the advantage of a Kozak-like element has the potential of being expressed as a separate internal translation unit, to generate a peptide with appropriate γ-carboxylase activity.
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Sam MR, Zomorodipour A, Haddad-Mashadrizeh A, Ghorbani M, Kardar GA, Sam S. Functions of the Heterologous Intron-Derived Fragments Intra and Extra Factor IX-cDNA Coding Region on the Human Factor IX Expression in HepG2 and Hek-293T Cells. IRANIAN JOURNAL OF BIOTECHNOLOGY 2018; 16:e1753. [PMID: 30805387 PMCID: PMC6371630 DOI: 10.21859/ijb.1753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 01/03/2018] [Accepted: 01/13/2018] [Indexed: 11/27/2022]
Abstract
Background Human FIX (hFIX) gene transfer into hepatocytes has provided a novel approach for treatment of hemophilia B. To obtain an improved expression of hFIX, the functional hFIX-expressing plasmids with appropriate intron-derived fragments which facilitate transcription and promote an efficient 3′-end formation of mRNAs are required. Objectives We aim to evaluate the functions of the heterologous intron-derived fragments intra and extra hFIX-cDNA coding region with respect to the hFIX expression in the hepatocytes and kidney cells. Materials and Methods HepG2 cells as differentiated hepatocytes and Hek-293T cells as embryonic kidney cells were transfected with the different hFIX-expressing plasmids containing various combinations of the two human beta-globin (hBG) introns within the hFIX-cDNA and Kozak sequence. In the next stage, as a hepatocyte-specific sequence, the rat aldolase B intronic enhancer sequence (rABE), was isolated from the first intron of the rat aldoase B gene and inserted within the upstream CMV promoter (CMVp) and efficacies of the engineered vectors were investigated in the stably-transfected HepG2 cells. Results Our data indicate that the intron-less construct and hBG intron-I containing construct are more effective with regard to hFIX expression compared to other constructs in Hek-293 cells. In HepG2 cells, the rABE in combination with CMVp in context of intron-less plasmid induced an increase in total expression of hFIX protein dramatically; ranging from 2.3 to 40 folds increase compared to other constructs. The rABE in combination with CMVp in the hBG intron-I, hBG intron-II, and hBG intron-I,II containing plasmids induced 3.7, 2, and 1.6-fold increase in the total expression of hFIX protein, respectively. The presence of both hBG intronic sequences within the hFIX-cDNA induced a higher secretion level of hFIX than either intron-I or II alone and provided correctly spliced hFIX transcripts in HepG2 and kidney cell lines. The intron-less construct with or without rABE induced the highest hFIX mRNA levels in HepG2 and Hek-293T cells respectively compared to other constructs. Conclusions The embryonic kidney cells in addition to the differentiated hepatic cell lines could be successfully targeted by plasmid vectors. The intron-less and hBG intron-I containing plasmids represent a particular interest in producing recombinant hFIX in Hek-293T cells. The synergistic function on the hFIX expression that was achieved by combining the CMVp with the liver-specific rABE would be a useful approach for future designing of the expression cassettes for hepatocyte-mediated gene expression in hemophilia B.
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Affiliation(s)
- Mohammad Reza Sam
- Department of Cellular and Molecular Biotechnology, Institute of Biotechnology, Urmia University, Urmia, Iran
| | - Alireza Zomorodipour
- Department of Molecular Medicine, Institute of Medical Biotechnology, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran
| | | | - Mahdi Ghorbani
- Department of Molecular Medicine, Institute of Medical Biotechnology, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran
| | - Gholam Ali Kardar
- Immunology, Asthma and Allergy Research Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Sohrab Sam
- Department of Cellular and Molecular Biotechnology, Institute of Biotechnology, Urmia University, Urmia, Iran
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Azadbakhsh AS, Sam MR, Farokhi F. Bioengineering of differentiated hepatocytes with human factor IX-expressing plasmids in vitro. Bioengineered 2016; 7:497-503. [PMID: 27458870 DOI: 10.1080/21655979.2016.1207018] [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: 10/21/2022] Open
Abstract
For somatic gene therapy of hemophilia B, hepatocytes as the main cellular host for expression of hFIX are attractive targets. In gene therapy protocols, an efficient expression vector equipped with cis-regulatory elements such as introns is required. With this in mind, hFIX-expressing plasmids equipped with different combinations of 2 human β-globin (hBG) introns inside the hFIX-cDNA and Kozak element were used for bioengineering of HepG2 cells as a model for differentiated hepatocytes and CHO cells a cell line generally used to produce recombinant hFIX (rhFIX). In HepG2 cells, the highest hFIX secretion level occurred for the intron-less plasmid with 8.5 to 53.8- fold increases, while in CHO cells, the hBG intron-I containing plasmid induced highest hFIX secretion level with 2.3 to 14.3-fold increases as compared to other plasmids. The first hBG intron appears to be more effective than the second one in both cell lines. The expression level was further increased upon the inclusion of the Kozak element. The highest hFIX activity was obtained from the cells that carrying the intron-less plasmids with 470 mU/ml and 25 mU/ml for HepG2 and CHO cells respectively. Secretion of active hFIX by all constructs was documented except for hBG intron-II containing construct in both cell lines. HepG2 cells were able to secret higher hFIX levels by 0.6 to 112.2-fold increases with activity by 5.3 to 16.4-fold increases compared to CHO cells transfected with the same constructs. Presence of both hBG intron-I and II inside the hFIX-cDNA provides properly spliced hFIX transcripts in both cell lines. In conclusion, the advantages of hBG introns as attractive cis-regulatory elements to obtain higher expression level of hFIX particularly in CHO cells were demonstrated. Hepatocytes could be effectively bioengineered with the use of plasmid vectors and this strategy may provide a potential in-vitro source of functional hepatocytes for ex-vivo gene therapy of hemophilias and production of rhFIX in vitro.
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Affiliation(s)
- Azadeh Sadat Azadbakhsh
- a Department of Cellular and Molecular Biotechnology , Institute of Biotechnology, Urmia University , Urmia , Iran
| | - Mohammad Reza Sam
- a Department of Cellular and Molecular Biotechnology , Institute of Biotechnology, Urmia University , Urmia , Iran
| | - Farrah Farokhi
- b Department of Histology and Embryology , Faculty of Science, Urmia University , Urmia , Iran
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Sam MR, Azadbakhsh AS, Farokhi F, Rezazadeh K, Sam S, Zomorodipour A, Haddad-Mashadrizeh A, Delirezh N, Mokarizadeh A. Genetic modification of bone-marrow mesenchymal stem cells and hematopoietic cells with human coagulation factor IX-expressing plasmids. Biologicals 2016; 44:170-7. [PMID: 26928674 DOI: 10.1016/j.biologicals.2016.01.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Revised: 12/30/2015] [Accepted: 01/13/2016] [Indexed: 11/17/2022] Open
Abstract
Ex-vivo gene therapy of hemophilias requires suitable bioreactors for secretion of hFIX into the circulation and stem cells hold great potentials in this regard. Viral vectors are widely manipulated and used to transfer hFIX gene into stem cells. However, little attention has been paid to the manipulation of hFIX transgene itself. Concurrently, the efficacy of such a therapeutic approach depends on determination of which vectors give maximal transgene expression. With this in mind, TF-1 (primary hematopoietic lineage) and rat-bone marrow mesenchymal stem cells (BMSCs) were transfected with five hFIX-expressing plasmids containing different combinations of two human β-globin (hBG) introns inside the hFIX-cDNA and Kozak element and hFIX expression was evaluated by different methods. In BMSCs and TF-1 cells, the highest hFIX level was obtained from the intron-less and hBG intron-I,II containing plasmids respectively. The highest hFIX activity was obtained from the cells that carrying the hBG intron-I,II containing plasmids. BMSCs were able to produce higher hFIX by 1.4 to 4.7-fold increase with activity by 2.4 to 4.4-fold increase compared to TF-1 cells transfected with the same constructs. BMSCs and TF-1 cells could be effectively bioengineered without the use of viral vectors and hFIX minigene containing hBG introns could represent a particular interest in stem cell-based gene therapy of hemophilias.
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Affiliation(s)
- Mohammad Reza Sam
- Department of Cellular and Molecular Biotechnology, Institute of Biotechnology, Urmia University, Urmia, Iran; Department of Histology and Embryology, Faculty of Science, Urmia University, Urmia, Iran.
| | - Azadeh Sadat Azadbakhsh
- Department of Cellular and Molecular Biotechnology, Institute of Biotechnology, Urmia University, Urmia, Iran; Department of Histology and Embryology, Faculty of Science, Urmia University, Urmia, Iran
| | - Farrah Farokhi
- Department of Histology and Embryology, Faculty of Science, Urmia University, Urmia, Iran
| | - Kobra Rezazadeh
- Department of Cellular and Molecular Biotechnology, Institute of Biotechnology, Urmia University, Urmia, Iran
| | - Sohrab Sam
- Department of Cellular and Molecular Biotechnology, Institute of Biotechnology, Urmia University, Urmia, Iran
| | - Alireza Zomorodipour
- Department of Molecular Genetics, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran
| | | | - Nowruz Delirezh
- Department of Microbiology, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran
| | - Aram Mokarizadeh
- Department of Immunology, Faculty of Medicine, Kurdistan University of Medical Sciences, Sanandaj, Iran
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Vatandoost J, Zomorodipour A, Sadeghizadeh M, Aliyari R, Bos MHA, Ataei F. Expression of biologically active human clotting factor IX in Drosophila S2 cells: γ-carboxylation of a human vitamin K-dependent protein by the insect enzyme. Biotechnol Prog 2011; 28:45-51. [PMID: 22012919 DOI: 10.1002/btpr.723] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2011] [Revised: 08/03/2011] [Indexed: 01/12/2023]
Abstract
The Drosophila γ-glutamyl carboxylase (dγC) has substrate recognition properties similar to that of the vertebrate γ-carboxylase (γC), and its carboxylated product yield, in vitro, was shown to be more than that obtained with the human enzyme. However, whether the Drosophila enzyme is able to γ-carboxylate the human vitamin K-dependent (VKD) proteins, such as the human coagulation factor IX (hFIX), as synthesized in cultured Drosophila cells was not known. To examine this possibility, the Drosophila Schnider (S2) cell line was transfected with a metallothionein promoter-regulated hFIX-expressing plasmid. After induction with copper ion, expression efficiency of the active hFIX was analyzed by performing enzyme-linked immunosorbent assey (ELISA) and coagulation test on the culture supernatant of the transfected S2 cells during 72 h of postinduction. In comparison with Chinese hamster ovary cell line, S2 cells showed higher (≈ 12-fold) expression level of the hFIX. The γ-carboxylation of the Drosophila-derived hFIX was confirmed by evaluation of the expressed protein, after being precipitated with barium citrate. The biological activity of the S2 cell-derived hFIX indicated the capability of S2 cells to fulfill the required γ-carboxylation of the expressed hFIX. Coexpression of the human γ-glutamyl carboxylases (hγC) was also shown to improve both expression and γ-carboxylation of the hFIX. This is the first in vivo data to describe the ability of the dγC to recognize the human-based propeptide as substrate, which is an essential step for production of biologically active γ-carboxylated VKD proteins.
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Affiliation(s)
- Jafar Vatandoost
- Department of Genetics, Tarbiat Modares University, Tehran, Iran
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A study of the expression of functional human coagulation factor IX in keratinocytes using a nonviral vector regulated by K14 promoter. Appl Biochem Biotechnol 2010; 162:1599-611. [PMID: 20397061 DOI: 10.1007/s12010-010-8941-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2009] [Accepted: 02/23/2010] [Indexed: 10/19/2022]
Abstract
Ex vivo gene therapy requires a suitable bioreactor for production and delivery of the gene products into a target tissue, and keratinocyte is suitable model in this regard because of its potential for systemic release of proteins. To establish a keratinocyte-specific expression system, a mammalian-based expression plasmid equipped with a 2,240-bp fragment from the human keratin 14 (k14) gene enhancer/promoter region was constructed and used for the insertion of the human coagulation factor IX (hFIX)-cDNA downstream the K14-derived regulatory elements. The human epidermal keratinocytes isolated from neonatal foreskin were cultivated in keratinocyte serum-free media and transfected with the recombinant plasmid. The K14-promoter-driven expression of recombinant hFIX (rhFIX) was evaluated by performing coagulation test as well as enzyme-linked immunosorbent assay on the cultured media collected from the transfected cells at various stages. The rhFIX corresponding transcript and protein were confirmed by performing reverse transcription PCR as well as immunoblotting experiments, respectively. Based on the coagulation activities obtained from the conditioned media of nine isolated clones, the hFIX expression levels vary from 5% to 39% of normal human plasma. Expression levels of the hFIX obtained in this study are comparable to those reported for viral systems. The obtained data supported the potential of keratinocyte for the expression and secretion of biologically active rhFIX and underscore the importance of the examined cis sequences for enhancing gene expression in a mammalian expression system. Besides, it has provided means for further bioengineering strategies to improve the expression efficiency of the hFIX in keratinocytes and other mammalian host cells.
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Haddad-Mashadrizeh A, Zomorodipour A, Izadpanah M, Sam MR, Ataei F, Sabouni F, Hosseini SJ. A systematic study of the function of the human beta-globin introns on the expression of the human coagulation factor IX in cultured Chinese hamster ovary cells. J Gene Med 2009; 11:941-50. [PMID: 19565465 DOI: 10.1002/jgm.1367] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Intronic sequences have the potential to improve gene expression in eukaryotes by a variety of mechanisms. In this context, human beta-globin (hBG) introns were inserted into the human factor IX (hFIX) cDNA in cytomegalovirus (CMV)-regulated plasmids. The resulting construct was then used for further expression analysis in vitro. METHODS Seven hFIX-expressing plasmids with different combinations of the two hBG introns and the Kozak element were constructed and used for a systematic expression analysis in cultured Chinese hamster ovary (CHO) cells. In parallel, the hBG intronic sequences were analysed for the presence of possible regulatory elements. RESULTS All the constructed plasmids resulted in transient expression of the hFIX. However, the coagulation activities varied according to the particular constructs used. Based on the hFIX antigenic assay, a wide range of variation was observed during persistent expression. The second hBG intron appears to be more effective than the first one. The expression level was further increased upon the inclusion of the Kozak element. Sequence analysis has detected several transcription factor binding (TFB) motifs in both of the introns, but with a higher frequency in the second one. CONCLUSIONS Potentials of hBG introns as enhancer-like elements for the expression of the hFIX in cultured CHO cells and a higher activity with respect to the second hBG intron compared to the first one were demonstrated. The larger number of TFBs in the second hBG intron reflects its stronger effect. The results obtained suggest possible synergistic functions of the hBG introns and Kozak on the expression level of hFIX in vitro.
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Abstract
Skin is an attractive target for gene modification to treat skin diseases, wound healing, or even systemic disorders. Although retroviral transduction results in permanent genetic modification, differentiation and eventually loss of the transduced cells from the epidermis and in temporary transgene expression. Therefore, it is important to develop methods that promote gene transfer to epidermal stem cells, which self-renew and regenerate the epidermis for extended periods of time. Here we describe an efficient protocol that results in high levels of retroviral gene transfer to human epidermal stem cells by immobilizing retrovirus on a recombinant fibronectin (rFN) fragment. In contrast to the traditional method, transduction on rFN promotes gene transfer to epidermal stem cells and prevents loss of clonogenic potential due to exposure of cells to retroviral supernatant. Notably, transduction on rFN does not require addition of toxic polycations such as polybrene. Overall this method provides a simple, fast, and efficient means to modify human epidermal stem cells for cutaneous gene therapy and for biological studies that require stable genetic modification.
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Affiliation(s)
- Pedro Lei
- Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York, Buffalo, NY, USA
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Kikuchi Y, Tamai K, Kaneda Y. Cutaneous gene delivery. J Dermatol Sci 2007; 50:87-98. [PMID: 17765482 DOI: 10.1016/j.jdermsci.2007.07.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2007] [Revised: 07/10/2007] [Accepted: 07/20/2007] [Indexed: 12/25/2022]
Abstract
Over the past decade, many approaches to transferring genes into the skin have been investigated. However, most such approaches have been specifically aimed against genodermatosis, and have not produced sufficient results. The goal of such research is to develop a method in which genes are transferred easily, efficiently and stably into keratinocytes, especially into keratinocyte stem cells, and in which the transgene expression persists without a reaction from the host immune response. Although accidental development of cancer has occurred in trials of gene therapy for X-linked severe combined immunodeficiency (X-SCID), resulting in slowing of the progress of this research, the lessons of these setbacks have been applied to further research. Moreover, combined with the techniques acquired from tissue engineering, recent developments in our knowledge about stem cells will lead to new treatments for genodermatoses. The present review summarizes the methods by which therapeutic genes can be transferred into keratinocytes, with discussion of how gene transfer efficiency can be improved, with particular emphasis on disruption of the skin barrier function. It concludes with discussion of the challenges and prospects of keratinocyte gene therapy, in terms of achieving efficient and long-lasting therapeutic effects.
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Affiliation(s)
- Yasushi Kikuchi
- Division of Gene Therapy Science, Graduate School of Medicine, Osaka University, 2-2 Yamada-oka, Suita, Osaka 565-0871, Japan
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Takahashi H, Honma M, Ishida-Yamamoto A, Namikawa K, Miwa A, Okado H, Kiyama H, Iizuka H. In Vitro and In Vivo Transfer of bcl-2 Gene into Keratinocytes Suppresses UVB-induced Apoptosis¶. Photochem Photobiol 2007. [DOI: 10.1562/0031-8655(2001)0740579ivaivt2.0.co2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Abstract
Wound healing can be problematic in several clinical settings because of massive tissue injury (burns), wound healing deficiencies (chronic wounds), or congenital conditions and diseases. Engineered skin substitutes have been developed to address the medical need for wound coverage and tissue repair. Currently, no engineered skin substitute can replace all of the functions of intact human skin. A variety of biologic dressings and skin substitutes have however contributed to improved outcomes for patients suffering from acute and chronic wounds. These include acellular biomaterials and composite cultured skin analogs containing allogeneic or autologous cultured skin cells.
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Affiliation(s)
- Dorothy M Supp
- Research Department, Shriners Hospitals for Children, Cincinnati Burns Hospital, Cincinnati, OH 45229, USA.
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Bajaj BG, Lei P, Andreadis ST. Efficient Gene Transfer to Human Epidermal Keratinocytes on Fibronectin: In Vitro Evidence for Transduction of Epidermal Stem Cells. Mol Ther 2005; 11:969-79. [PMID: 15922968 DOI: 10.1016/j.ymthe.2004.10.023] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2004] [Revised: 10/22/2004] [Accepted: 10/26/2004] [Indexed: 01/09/2023] Open
Abstract
The epidermis is an attractive target for gene therapy because it is easily accessible and has great potential as an ectopic site for protein delivery in vivo. Genetically modified keratinocytes can be expanded in culture and used to generate three-dimensional skin equivalents, which can deliver therapeutic proteins either locally or systemically for the treatment of wounds or systemic diseases. Here we present an optimum protocol that yields consistently high retroviral gene transfer on a substrate of recombinant fibronectin (rFN). Gene transfer on rFN depends strongly on virus concentration and the density of target cells. Interestingly, the kinetics of gene transfer varies depending upon the origin--mouse or human--of virus-producer cells. Most notably, long-term growth and clonogenic assays show that transduction on rFN promotes gene transfer to epidermal stem cells and prevents loss of clonogenic potential due to exposure of cells to retroviral supernatant. In contrast, the traditional protocol transduces mostly differentiated keratinocytes. We also show that skin equivalents prepared from genetically modified keratinocytes display high levels of transgene expression, mainly in the suprabasal layers. Our results are important for cutaneous gene therapy and for biological studies that require efficient and permanent genetic modification.
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Affiliation(s)
- Bharat G Bajaj
- Department of Chemical and Biological Engineering, Bioengineering Laboratory, 908 Furnas Hall, University at Buffalo, State University of New York, Amherst, NY 14260, USA
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Schwenter F, Bouche N, Pralong WF, Aebischer P. In vivo calcium deposition on polyvinyl alcohol matrix used in hollow fiber cell macroencapsulation devices. Biomaterials 2004; 25:3861-8. [PMID: 15020162 DOI: 10.1016/j.biomaterials.2003.10.030] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2003] [Accepted: 10/08/2003] [Indexed: 11/19/2022]
Abstract
The encapsulation of genetically modified cells represents a promising approach for the delivery of therapeutic proteins. The functionality of the device is dependent on the characteristics of the biomaterials, the procedures used in its confection and the adaptability of the encapsulated cells in the host. We report conditions leading to the development of calcifications on the polyvinyl alcohol (PVA) matrix introduced in hollow fiber devices for the encapsulation of primary human fibroblasts implanted in mice. The manufacturing procedures, batches of PVA matrix and cell lineages were assessed for their respective role in the development of the phenomenon. The results showed that the calcification is totally prevented by substituting phosphate-buffer saline with ultra-pure sterile water in the rinsing procedure of the matrix. Moreover, a positive correlation was found, when comparing two fibroblast cell lineages, between the level of lactate dehydrogenase (LDH) activity measured in the cells and the degree of calcium deposition. Higher LDH activity may decrease calcium depositions because it generates in the device a more acidic microenvironment inhibiting calcium precipitation. The present study defines optimized conditions for the encapsulation of primary human fibroblasts in order to avoid potentially detrimental calcifications and to allow long-term survival of encapsulated cells.
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Affiliation(s)
- F Schwenter
- Division of Surgical Research and Gene Therapy Center, CHUV, Lausanne University Medical School, Lausanne, Switzerland
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Schwenter F, Schneider BL, Pralong WF, Déglon N, Aebischer P. Survival of Encapsulated Human Primary Fibroblasts and Erythropoietin Expression Under Xenogeneic Conditions. Hum Gene Ther 2004; 15:669-80. [PMID: 15242527 DOI: 10.1089/1043034041361172] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Allogeneic cells are the most attractive source for cell transplantation, as the use of xenogeneic cells is hampered by safety concerns and the use of autologous cells involves practical difficulties. The immune rejection of allogeneic cells can be overcome by physical immunoprotection provided by polymer encapsulation. To study the variability of cell and donor sources, we compared different primary human cells as candidates for gene therapy-mediated delivery of human erythropoietin (hEpo). DARC-3.1 fibroblasts, MDX-01 fibroblasts, and ARPE-19 retinal pigment epithelial cells were encapsulated into polyethersulfone hollow fibers and implanted for 1 month in nude mice as well as in immunocompetent and FK506-immunosuppressed mice to test their in vivo resistance, with the assumption that xenogeneic conditions constitute a stringent model for human application. DARC-3.1 fibroblasts showed the best survival, prompting us to evaluate cell lineages from the same donor (DARC-3.2) or another donor (DARC-4.3 and DARC-4.4). With the exception of DARC-4.3, the remaining three lineages showed comparable survival in immunocompetent C3H and DBA/2J mice. DARC-3.1 fibroblasts were retrovirally engineered with hEpo cDNA, reaching a secretion level of 170 IU of hEpo per 10(6) cells per day. Encapsulated DARC-3.1-hEpo cells led to significantly increased hematocrits in the various hosts and under various transplantation conditions. The present study shows that encapsulated primary human DARC-3.1 fibroblasts are able to survive under xenogeneic conditions and, once engineered with hEpo cDNA, to increase the hematocrit of transplanted mice.
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Affiliation(s)
- F Schwenter
- Division of Surgical Research and Gene Therapy Center, Centre Hospitalier Universitaire Vaudois, Lausanne University Medical School, CH-1005 Lausanne, Switzerland
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Schwenter F, Déglon N, Aebischer P. Optimization of human erythropoietin secretion from MLV-infected human primary fibroblasts used for encapsulated cell therapy. J Gene Med 2003; 5:246-57. [PMID: 12666190 DOI: 10.1002/jgm.338] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND The transplantation of encapsulated cells genetically engineered to secrete human erythropoietin (hEpo) represents an alternative to repeated injections of the recombinant hormone for the treatment of Epo-responsive anemia. In the present study, the ability of primary human foreskin fibroblasts to secrete high levels of hEpo and the importance of cis-acting elements and infection conditions on transgene expression level were assessed. METHODS The transduction efficiency was first evaluated with beta-galactosidase (LacZ)-encoding retroviral vectors derived from the murine leukemia retrovirus (MLV) pseudotyped either with an amphotropic envelope or with the G glycoprotein of vesicular stomatitis virus (VSV-G). Human fibroblasts were then infected with an amphotropic hEpo-expressing retroviral vector, which was modified by insertion of a post-transcriptional regulatory element from the woodchuck hepatitis virus (WPRE) and a Kozak consensus sequence (KZ). Human Epo production was further optimized by increasing the multiplicity of infection and by selecting high producer cells. The survival and the transgene expression of these fibroblasts were finally evaluated in vivo. The cells were encapsulated into microporous hollow fibers and subcutaneously implanted in nude mice. RESULTS A secretion level of approximately 5 IU hEpo/10(6) cells/day was obtained with the basal vector. A 7.5-fold increase in transgene expression was observed with the insertion of WPRE and KZ elements. Finally, according to the optimization of infection conditions, we obtained a 40-fold increase in hEpo secretion, reaching approximately 200 IU hEpo/10(6) cells/day. The in vivo experiments showed an increase in the hematocrit during the first 2 weeks and elevated levels exceeding 60% were maintained over a 6-week period. CONCLUSIONS These results indicate that primary human fibroblasts represent a promising source for encapsulated cell therapy.
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Affiliation(s)
- F Schwenter
- Division of Surgical Research & Gene Therapy Center, CHUV, Lausanne University Medical School, 1011 Lausanne, Switzerland
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Bajaj B, Behshad S, Andreadis ST. Retroviral gene transfer to human epidermal keratinocytes correlates with integrin expression and is significantly enhanced on fibronectin. Hum Gene Ther 2002; 13:1821-31. [PMID: 12396615 DOI: 10.1089/104303402760372927] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Human epidermal keratinocytes are an important target for gene therapy because they can be easily expanded in culture and used to generate skin substitutes for the treatment of wounds, genetic diseases of the skin, and for delivery of proteins to the systemic circulation. Although retroviral transduction results in permanent genetic modification, differentiation and loss of transduced cells from the epidermis results in temporary transgene expression. To ensure permanent genetic modification, epidermal stem cells must be transduced with high efficiency. We evaluated gene transfer on two different substrates and found that the efficiency of gene transfer is substantially higher on a substrate of recombinant fibronectin (FN), when compared to tissue culture plastic (TCP). The rate of retroviral transduction on FN is four times faster than transduction on tissue culture plates and is independent of polybrene (PB). The transduction efficiency correlates with the levels of expression of integrin subunits alpha5, alpha2, and beta1, which have been shown to correlate with stem cell phenotype. Notably, cells that adhere rapidly to FN are transduced more efficiently than slowly adherent cells. In addition, integrin-blocking antibodies decrease the efficiency of gene transfer in a dose-dependent manner. Our results suggest that FN may enhance retroviral gene transfer to the least differentiated cells, thereby increasing the potential of genetically modified keratinocytes to treat short- and long-term disease states.
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Affiliation(s)
- Bharat Bajaj
- Bioengineering Laboratory, Department of Chemical Engineering, University at Buffalo, State University of New York, Amherst, NY 14260, USA
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18
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Affiliation(s)
- K J Pasi
- Division of Haematology, University of Leicester, Robert Kilpatrick Clinical Science Building, Leicester Royal Infirmary, Leicester LE2 7LX, UK.
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19
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Takahashi H, Honma M, Ishida-Yamamoto A, Namikawa K, Miwa A, Okado H, Kiyama H, Iizuka H. In vitro and in vivo transfer of bcl-2 gene into keratinocytes suppresses UVB-induced apoptosis. Photochem Photobiol 2001; 74:579-86. [PMID: 11683038 DOI: 10.1562/0031-8655(2001)074<0579:ivaivt>2.0.co;2] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Bcl-2 is a member of the large Bcl-2 family and protects cells from apoptosis. Ultraviolet B (UVB) irradiation induces apoptosis of keratinocytes that is known as "sunburn cells." Previously we reported that UVB irradiation induces apoptosis accompanied by sequential activation of caspase 8, 3 and 1 in keratinocytes, and that the process is inhibited by various caspase inhibitors. Using bcl-2-expressing adenovirus vector we investigated the effect of Bcl-2 on UVB-induced apoptosis. Adenovirus vector efficiently introduced bcl-2 gene in cultured normal mouse keratinocytes (NMK cells); almost all NMK cells (1 x 10(6)) were transfected at 1 x 10(8) plaque-forming unit (PFU)/mL. Bcl-2-transfected NMK cells were significantly resistant to UVB-induced apoptosis with the suppressive effect dependent on the Bcl-2 expression level. Following UVB irradiation caspase 8, 3 and 9 activities were stimulated in NMK cells, whereas in bcl-2-transfected cells only caspase 8, but not caspase 3 or 9, activity was stimulated. In order to investigate the effect of Bcl-2 in vivo topical application of Ad-bcl-2 on tape-stripped mouse skin was performed. Following the application Bcl-2 was efficiently overexpressed in almost all viable keratinocytes. The expression was transient with the maximal expression of Bcl-2 on the first day following the application of 1 x 10(9) PFU in 200 microL. The introduced Bcl-2 remained at least for 6 days. UVB irradiation (1250 J/m2) induced apoptosis within 12 h and the maximal effect was observed at 24 h in control mouse skin. Both bcl-2-transfected and topical caspase 3 inhibitor-treated mice skin were resistant to UVB-induced apoptosis. The suppressive effect of Bcl-2 was more potent than that of caspase 3 inhibitor application. Topical application of empty adenovirus vector alone had no effect on Bcl-2 expression or UVB-induced apoptosis. These results indicate that adenovirus vector is an efficient gene delivery system into keratinocytes and that Bcl-2 is a potent inhibitor of UVB-induced apoptosis both in vitro and in vivo.
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Affiliation(s)
- H Takahashi
- Department of Dermatology, Asahikawa Medical College, 2-1-1 Midorigaoka higashi, Asahikawa 078-8510, Japan.
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20
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Andreadis ST, Hamoen KE, Yarmush ML, Morgan JR. Keratinocyte growth factor induces hyperproliferation and delays differentiation in a skin equivalent model system. FASEB J 2001. [DOI: 10.1096/fsb2fj000324com] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Stylianos T. Andreadis
- Center for Engineering in Medicine and Surgical Services, Massachusetts General Hospital Harvard Medical School and Shriners Burns Hospital Boston Massachusetts 02114 USA
| | - Karen E. Hamoen
- Center for Engineering in Medicine and Surgical Services, Massachusetts General Hospital Harvard Medical School and Shriners Burns Hospital Boston Massachusetts 02114 USA
| | - Martin L. Yarmush
- Center for Engineering in Medicine and Surgical Services, Massachusetts General Hospital Harvard Medical School and Shriners Burns Hospital Boston Massachusetts 02114 USA
| | - Jeffrey R. Morgan
- Center for Engineering in Medicine and Surgical Services, Massachusetts General Hospital Harvard Medical School and Shriners Burns Hospital Boston Massachusetts 02114 USA
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21
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Andreadis ST, Hamoen KE, Yarmush ML, Morgan JR. Keratinocyte growth factor induces hyperproliferation and delays differentiation in a skin equivalent model system. FASEB J 2001; 15:898-906. [PMID: 11292649 DOI: 10.1096/fj.00-0324com] [Citation(s) in RCA: 109] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Keratinocyte growth factor (KGF) is a paracrine mediator of epithelial cell growth. To examine the direct effects of KGF on the morphogenesis of the epidermis, we generated skin equivalents in vitro by seeding human keratinocytes on the papillary surface of acellular dermis and raising them up to the air-liquid interface. KGF was either added exogenously or expressed by keratinocytes via a recombinant retrovirus encoding KGF. KGF induced dramatic changes to the 3-dimensional organization of the epidermis including pronounced hyperthickening, crowding, and elongation of the basal cells, flattening of the rete ridges, and a ripple-like pattern in the junction of stratum corneum and granular layers. Quantitative immunostaining for the proliferation antigen, Ki67, revealed that in addition to increasing basal proliferation, KGF extended the proliferative compartment by inducing suprabasal cell proliferation. KGF also induced expression of the integrin alpha 5 beta 1 and delayed expression of keratin 10 and transglutaminase. However, barrier formation of the epidermis was not disrupted. These results demonstrate for the first time that a single growth factor can alter the 3-dimensional organization and proliferative function of an in vitro epidermis. In addition to new strategies for tissue engineering, such a well-defined system will be useful for analyzing growth factor effects on the complex links between cell proliferation, cell movement and differentiation within a stratified tissue.
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Affiliation(s)
- S T Andreadis
- Center for Engineering in Medicine and Surgical Services, Massachusetts General Hospital, Harvard Medical School and Shriners Burns Hospital, Boston, Massachusetts 02114, USA
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22
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Nathwani AC, Davidoff A, Hanawa H, Zhou JF, Vanin EF, Nienhuis AW. Factors influencing in vivo transduction by recombinant adeno-associated viral vectors expressing the human factor IX cDNA. Blood 2001; 97:1258-65. [PMID: 11222368 DOI: 10.1182/blood.v97.5.1258] [Citation(s) in RCA: 107] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Long-term expression of coagulation factor IX (FIX) has been observed in murine and canine models following administration of recombinant adeno-associated viral (rAAV) vectors into either the portal vein or muscle. These studies were designed to evaluate factors that influence rAAV-mediated FIX expression. Stable and persistent human FIX (hFIX) expression (> 22 weeks) was observed from 4 vectors after injection into the portal circulation of immunodeficient mice. The level of expression was dependent on promoter with the highest expression, 10% of physiologic levels, observed with a vector containing the cytomegalovirus (CMV) enhancer/beta-actin promoter complex (CAGG). The kinetics of expression after injection of vector particles into muscle, tail vein, or portal vein were similar with hFIX detectable at 2 weeks and reaching a plateau by 8 weeks. For a given dose, intraportal administration of rAAV CAGG-FIX resulted in a 1.5-fold or 4-fold higher level of hFIX compared to tail vein or intramuscular injections, respectively. Polymerase chain reaction analysis demonstrated predominant localization of the rAAV FIX genome in liver and spleen after tail vein injection with a higher proportion in liver after portal vein injection. Therapeutic levels of hFIX were detected in the majority of immunocompetent mice (21 of 22) following intravenous administration of rAAV vector without the development of anti-hFIX antibodies, but hFIX was not detected in 14 immunocompetent mice following intramuscular administration, irrespective of strain. Instead, neutralizing anti-hFIX antibodies were detected in all the mice. These observations may have important implications for hemophilia B gene therapy with rAAV vectors.
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Affiliation(s)
- A C Nathwani
- Division of Experimental Hematology, Department of Hematology/ Oncology, St Jude Children's Research Hospital, Memphis, TN 38105, USA
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23
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Abstract
Hemophilia A and B are X-chromosome linked recessive bleeding disorders that result from a deficiency in factor VIII (FVIII) and factor IX (FIX) respectively. Though factor substitution therapy has greatly improved the lives of hemophiliac patients, there are still limitations to the current treatment that have triggered interest in alternative treatments by gene therapy. Significant progress has recently been made in the development of gene therapy for the treatment of hemophilia A and B. These advances parallel the technical improvements of existing vector systems including MoMLV-based retroviral, adenoviral and AAV vectors, and the development of new delivery methods such as lentiviral vectors, helper-dependent adenoviral vectors and improved non-viral gene delivery methods. Therapeutic and physiologic levels of FVIII and FIX could be achieved in FVIII- and FIX-deficient mice and hemophilia dogs by different gene therapy approaches. Long-term correction of the bleeding disorders and in some cases a permanent cure has been realized in these preclinical studies. However, the induction of neutralizing antibodies often precludes stable phenotypic correction. Another complication is that certain promoters are prone to transcriptional inactivation in vivo, precluding long-term FVIII or FIX expression. Several gene therapy phase I clinical trials are currently ongoing in patients suffering from severe hemophilia A or B. No significant adverse side-effects were reported, and semen samples were negative for vector sequences by sensitive PCR assays. Most importantly, some subjects report fewer bleeding episodes and occasionally have very low levels of clotting factor activity detected. The results from the extensive preclinical studies in normal and hemophilic animal models and encouraging preliminary clinical data indicate that the simultaneous development of different strategies is likely to bring a permanent cure for hemophilia one step closer to reality.
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Affiliation(s)
- M K Chuah
- Center for Transgene Technology and Gene Therapy, Flanders Interuniversity Institute for Biotechnology, University of Leuven, Belgium
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Mizuno H, Emi N, Abe A, Takahashi I, Saito H, Matsuno M, Sumi Y, Hata KI, Ueda M. An ex vivo model for gene therapy of hemophilia B using cultured human oral mucosal epithelium. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2000. [DOI: 10.1016/s0928-4931(00)00175-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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25
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Bevan S, Martin R, Mckay IA. The production and applications of genetically modified skin cells. Biotechnol Genet Eng Rev 2000; 16:231-56. [PMID: 10819081 DOI: 10.1080/02648725.1999.10647977] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- S Bevan
- Blond McIndoe Centre, Queen Victoria Hospital, East Grinstead, West Sussex, UK
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26
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Abstract
To test the hypothesis that factor VIII expressed in the epidermis can correct hemophilia A, we generated transgenic mice in a factor VIII–deficient background that express human factor VIII under control of the involucrin promoter. Mice from 5 transgenic lines had both phenotypic correction and plasma factor VIII activity. In addition to the skin, however, some factor VIII expression was detected in other tissues that have stratified squamous epithelia. To determine whether an exclusively cutaneous source of factor VIII could correct factor VIII deficiency, we grafted skin explants from transgenic mice onto mice that are double knockouts for the factor VIII and RAG-1 genes. Two graft recipients had plasma factor VIII activity of 4% to 20% of normal and improved whole blood clotting compared with factor VIII–deficient mice. Thus, expression of factor VIII from the epidermis can correct hemophilia A mice, thereby supporting the feasibility of cutaneous gene therapy for systemic disease.
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27
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Hortelano G, Chang PL. Gene therapy for hemophilia. ARTIFICIAL CELLS, BLOOD SUBSTITUTES, AND IMMOBILIZATION BIOTECHNOLOGY 2000; 28:1-24. [PMID: 10676574 DOI: 10.3109/10731190009119782] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Hemophilia A and B are X-linked genetic disorders caused by deficiency of the coagulation factors VIII and IX, respectively. Because of the health hazards and costs of current product replacement therapy, much effort is devoted to the development of gene therapy for these disorders. Approaches to gene therapy for the hemophilias include: ex vivo gene therapy in which cells from the intended recipients are explanted, genetically modified to secrete Factor VIII or IX, and reimplanted into the donor; in vivo gene therapy in which Factor VIII or IX encoding vectors are directly injected into the recipient; and non-autologous gene therapy in which universal cell lines engineered to secrete Factor VIII or IX are enclosed in immuno-protective devices before implantation into recipients. Research into these approaches is aided by the many murine and canine models available. While problems of achieving high and sustained levels of factor delivery, and issues related to efficacy, safety and cost are still to be resolved, progress in gene therapy for the hemophilias has been encouraging and is likely to reach human clinical trial in the foreseeable future.
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Affiliation(s)
- G Hortelano
- Department of Pathology, McMaster University, Hamilton, Ontario, Canada
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28
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Taichman LB. Systemic replacement therapy from genetically modified epidermal keratinocytes. PROCEEDINGS OF THE ASSOCIATION OF AMERICAN PHYSICIANS 1999; 111:206-10. [PMID: 10354360 DOI: 10.1046/j.1525-1381.1999.99226.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Epidermal keratinocytes are a potential vehicle for gene transfer and systemic delivery. We review data showing that epidermis-secreted protein does indeed reach the circulation, and we discuss factors that bear upon the issue of how much protein epidermal keratinocytes can deliver to the circulation.
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Affiliation(s)
- L B Taichman
- Department of Dermatology and Oral Biology and Pathology, State University of New York at Stony Brook, NY 11794-8702, USA
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29
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Terskikh VV, Vasiliev AV. Cultivation and transplantation of epidermal keratinocytes. INTERNATIONAL REVIEW OF CYTOLOGY 1999; 188:41-72. [PMID: 10208010 DOI: 10.1016/s0074-7696(08)61565-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Transplantation of autologous cultured keratinocytes is the most advanced area of tissue engineering which has clinical application in restoration of skin lesions. In vitro, disaggregated keratinocytes undergo activation and after adhesion and histogenic aggregation form three-dimensional epithelial sheets suitable for grafting on prepared wounds that provide a reparative environment. Epidermal stem cells survive and proliferate in culture, retaining their potential to differentiate and to produce neoepidermis. Reconstructed skin is physiologically compatible to split-thickness autografts. Autotransplantation of cultured keratinocytes is a promising technique for gene therapy. In many cases allografting of cultured keratinocytes promotes wound healing by stimulation of epithelialization. Banking of cryopreserved keratinocytes is a significant improvement in usage of cultured keratinocytes for wound healing. Skin substitutes reconstructed in vitro that have morphological, biochemical, and functional features of the native tissue are of interest as model systems that enable extrapolation to situations in vivo.
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Affiliation(s)
- V V Terskikh
- Institute of Developmental Biology, Russian Academy of Sciences, Moscow, Russia
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30
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Mizuno H, Emi N, Abe A, Takahashi I, Kojima T, Saito H, Sumi Y, Hata KI, Ueda M. Successful culture and sustainability in vivo of gene-modified human oral mucosal epithelium. Hum Gene Ther 1999; 10:825-30. [PMID: 10210149 DOI: 10.1089/10430349950018571] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Human oral mucosal cells are an attractive site for tissue engineering because they are the most accessible cells in the body and easy to manipulate in vitro. They thus have possibilities for targeting by somatic gene therapy. We examined the efficiency of retrovirus-mediated gene transfer and the construction of mucosal epithelium in vivo. Human oral mucosal cells were transduced with a retroviral vector carrying the lacZ gene at high efficiency and constructed epithelium after G418 selection with 3T3 cells in vitro. The cultured oral mucosal epithelium membrane was then grafted onto immunodeficient mice. Beta-Gal expression was detected histochemically in vivo 5 weeks after grafting. Furthermore, we transduced factor IX cDNA into the mucosal epithelium membrane, and it was then transplanted into nude mice. Between 0.6 and 1.8 ng of human factor IX per milliliter was found in mouse plasma, and the production was continued for 23 days in vivo. These results confirmed that the oral mucosal epithelium is an ideal target tissue for gene therapy or tissue engineering.
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Affiliation(s)
- H Mizuno
- Department of Oral Surgery, Nagoya University School of Medicine, Japan.
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31
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White SJ, Page SM, Margaritis P, Brownlee GG. Long-term expression of human clotting factor IX from retrovirally transduced primary human keratinocytes in vivo. Hum Gene Ther 1998; 9:1187-95. [PMID: 9625258 DOI: 10.1089/hum.1998.9.8-1187] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
A persistent obstacle that has hampered gene transfer experiments is the short-term nature of transgene expression in vivo. In this article we present evidence for sustained expression from primary human keratinocytes, using the retroviral vector MFG. Primary keratinocytes were transduced in culture with the MFG retroviral vector containing the coding region from factor IX cDNA. Transduced keratinocytes, which secreted on average 830 ng of factor IX/10(6) cells/24 hr in tissue culture, were used to form a bilayered skin equivalent and grafted onto nude mice under a silicone transplantation chamber. Between 0.1 and 2.75 ng of human factor IX per milliliter was found in mouse plasma for more than 1 year, suggesting that keratinocyte stem cells were both transduced and grafted. The results show, for the first time, that long-term expression is obtainable in retrovirally transduced keratinocytes after transplantation.
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Affiliation(s)
- S J White
- Chemical Pathology Unit, Sir William Dunn School of Pathology, University of Oxford, UK
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Gorman L, Suter D, Emerick V, Schümperli D, Kole R. Stable alteration of pre-mRNA splicing patterns by modified U7 small nuclear RNAs. Proc Natl Acad Sci U S A 1998; 95:4929-34. [PMID: 9560205 PMCID: PMC20190 DOI: 10.1073/pnas.95.9.4929] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
In several forms of beta-thalassemia, mutations in the second intron of the beta-globin gene create aberrant 5' splice sites and activate a common cryptic 3' splice site upstream. As a result, the thalassemic beta-globin pre-mRNAs are spliced almost exclusively via the aberrant splice sites leading to a deficiency of correctly spliced beta-globin mRNA and, consequently, beta-globin. We have designed a series of vectors that express modified U7 snRNAs containing sequences antisense to either the aberrant 5' or 3' splice sites in the IVS2-705 thalassemic pre-mRNA. Transient expression of modified U7 snRNAs in a HeLa cell line stably expressing the IVS2-705 beta-globin gene restored up to 65% of correct splicing in a sequence-specific and dose-dependent manner. Cell lines that stably coexpressed IVS2-705 pre-mRNA and appropriately modified U7 snRNA exhibited up to 55% of permanent restoration of correct splicing and expression of full-length beta-globin protein. This novel approach provides a potential alternative to gene replacement therapies.
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Affiliation(s)
- L Gorman
- Lineberger Comprehensive Cancer Center and Department of Pharmacology, University of North Carolina, Chapel Hill, NC 27599, USA
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33
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Kolodka TM, Garlick JA, Taichman LB. Evidence for keratinocyte stem cells in vitro: long term engraftment and persistence of transgene expression from retrovirus-transduced keratinocytes. Proc Natl Acad Sci U S A 1998; 95:4356-61. [PMID: 9539741 PMCID: PMC22493 DOI: 10.1073/pnas.95.8.4356] [Citation(s) in RCA: 164] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Epidermis is renewed by a population of stem cells that have been defined in vivo by slow turnover, label retention, position in the epidermis, and enrichment in beta1 integrin, and in vitro by clonogenic growth, prolonged serial passage, and rapid adherence to extracellular matrix. The goal of this study is to determine whether clonogenic cells with long-term growth potential in vitro persist in vivo and give rise to a fully differentiated epidermis. Human keratinocytes were genetically labeled in culture by transduction with a retrovirus encoding the lacZ gene and grafted to athymic mice. Analysis of the cultures before grafting showed that 21.1-27.8% of clonogenic cells with the capacity for >30 generations were successfully transduced. In vivo, beta-galactosidase (beta-gal) positive cells participated in the formation of a fully differentiated epithelium and were detected throughout the 40-week postgraft period, initially as loosely scattered clusters and later as distinct vertical columns. Viable cells recovered from excised grafts were seeded at clonal densities and 23.3-33.3% of the colonies thus formed were beta-gal positive. In addition, no evidence of transgene inactivation was obtained: all keratinocyte colonies recovered from grafted tissue that were beta-gal negative also lacked the lacZ transgene. These results show that cells with long-term growth properties in vitro do indeed persist in vivo and form a fully differentiated epidermis, thereby exhibiting the properties of stem cells.
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Affiliation(s)
- T M Kolodka
- Department of Oral Biology and Pathology, State University of New York at Stony Brook, Stony Brook, NY 11794-8702, USA
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