Optimization of the Sleeping Beauty Transposon System to Achieve Stable Transgene Expression in Human CD34+ Hematopoietic Progenitor Cells

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3527-3527
Author(s):  
Teiko Sumiyoshi ◽  
Roger P Hollis ◽  
Nathalia Holt ◽  
Donald B. Kohn
Keyword(s):  
Gene Transfer ◽  
Progenitor Cells ◽  
Transgene Expression ◽  
Sleeping Beauty ◽  
Egfp Expression ◽  
Stable Gene ◽  
Human Cd34 ◽  
Gfp Reporter ◽  
Cd34 Cells

Abstract Sleeping Beauty (SB) transposon-mediated integration has been shown to achieve long-term transgene expression in a wide range of host cells. Transposon-mediated gene integration may have advantages over viral vectors, with a greater transgene carrying capacity and potentially safer integration site profile. Due to these characteristics of SB, there has been great interest in its potential use in hematopoietic stem cell (HSC) gene therapy. In this study, we optimized the SB transposon-mediated gene transfer system to achieve higher stable transgene expression in K562 human erythroleukemia cells, Jurkat human T-lymphoid cells, and primary human CD34+ hematopoietic progenitor cells. The SB transposon system was optimized by two approaches: to increase the transposition efficacy, a hyperactive mutant of SB, HSB16, was used (Baus et al.; Mol Ther12:1148, 2005); to optimize the expression of the SB transposase and the transgene cassette carried by the transposon, three different viral and cellular promoters were evaluated, including the modified MPSV long terminal repeat (MNDU3) enhancer-promoter, the human cytomegalovirus (hCMV) immediate-early region enhancer-promoter, and the human elongation factor 1 (hEF1a) promoter. SB components were delivered in trans into the target cells by nucleoporation. The SB transposon-mediated integration efficacy was assessed by integrated transgene (enhanced green fluorescent protein [eGFP]) expression using fluorescent-activated cell sorting (FACS) analysis over 3–4 weeks. The functional assay showed that HSB16 was a more efficient enzyme compared to the original SB. In purified human cord blood CD34+ cells, HSB16 achieved nearly 7-fold higher long-term transgene expression with 90% less plasmid DNA (from 10 mcg of SB reduced to 1 mcg of HSB16) than the original SB transposase. The highest level of stable transgene integration in all three cell types was achieved using the hEF1a promoter to express HSB16 in comparison to either the hCMV or MND promoter. Our data also suggested that optimal GFP reporter gene expression from the integrated transposon was influenced by the type of promoter and the target cell type. Significantly higher levels of eGFP expression (5-fold) were achieved with the hEF1a promoter in Jurkat human T cells, compared to that achieved with the MND promoter; in contrast the MND promoter expressed GFP at the highest level in K562 myeloid cells. In primary human CD34+ cord blood progenitors, optimal transgene integration and expression was achieved using the hEF1a promoter to express the SB transposase combined with the MND promoter to express GFP reporter, when studied under conditions directing myeloid differentiation. Stable transgene expression was achieved at levels up to 27% for over 4 weeks after optimized gene transfer to CD34+ cells (ave=17%, n=4). In vivo studies evaluating engraftment and differentiation of the SB-modified human CD34+ progenitor cells are currently in progress. In conclusion, the optimized SB transposon system in primary human CD34+ hematopoietic progenitors reported here has improved the stable gene transfer efficiency by 29-fold, compared to our prior published data (< 1% - Hollis et al.; Exp Hematol34:1333, 2006). The long-term stable gene expression achieved by our optimized SB transposon system shows promise for further advancement of non-viral based HSC gene therapy.

Stable Gene Transfer and Expression in Human Primary T-Cells by the Sleeping Beauty Transposon System.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 5539-5539
Author(s):  
Xianzheng Zhou ◽  
Xin Huang ◽  
Andrew C. Wilber ◽  
Lei Bao ◽  
Dong Tuong ◽  
...  
Keyword(s):  
Gene Expression ◽  
T Cells ◽  
T Cell ◽  
Gene Transfer ◽  
Transgene Expression ◽  
Sleeping Beauty ◽  
Stable Gene ◽  
Cell Clones ◽  
Stable Gene Expression

Abstract The Sleeping Beauty (SB) transposon system is a non-viral DNA delivery system in which a transposase directs integration of an SB transposon into TA-dinucleotide sites in the genome. To determine whether the SB transposon system can mediate integration and long-term transgene expression in human primary T-cells, freshly isolated peripheral blood lymphocytes (PBLs) without prior activation were nucleofected with SB vectors carrying a DsRed reporter gene. Plasmids containing the SB transposase on the same (cis) (n=10) or separate molecule (trans) (n=8) as the SB transposon mediated long-term and stable reporter gene expression in human primary T-cells. We observed that delivery of SB transposase-encoding plasmid in trans effectively mediated stable gene expression in primary T-cells, exhibiting about a 3-fold increase (11% vs. 3% with 10 microgram plasmid on day 21) in potency in comparison with the cis vector (p&lt;0.0001). In addition, a transposase mutant construct was incapable of mediating stable gene expression in human PBLs (n=6, p&lt;0.0001), confirming that catalytic DDE domain is necessary for transposition in human primary T-cells. Immunophenotyping analysis in transposed T-cells showed that both CD4 and CD8 T-cells were transgene positive. SB-mediated high level of transgene expression in human T-cells was maintained in culture for at least 4 months without losing observable expression. Southern hybridization analysis showed a variety of transposon integrants among the 6 DsRed positive T-cell clones and no transposon sequences identifiable in the 2 DsRed negative clones. Sequencing of transposon:chromosome junctions in 5 out of 6 transposed T-cell clones confirmed that stable gene expression was due to SB-mediated transposition. In other studies, PBLs were successfully transfected using the SB transposon system and shown to stably and functionally express a fusion protein consisting of a surface receptor useful for positive T-cell selection and a “suicide” gene useful for elimination of transfected T-cells after chemotherapy. This study is the first report demonstrating that the SB transposon system can mediate stable gene transfer in human primary PBLs, which may be more advantageous for T-cell based gene therapies over widely used virus-based or conventional mammalian DNA vectors in terms of simplicity, stability, efficiency and safety.

Reversibility of CD34 expression on human hematopoietic stem cells that retain the capacity for secondary reconstitution

Blood ◽  
2003 ◽  
Vol 101 (1) ◽  
pp. 112-118 ◽  
Author(s):  
Mo A. Dao ◽  
Jesusa Arevalo ◽  
Jan A. Nolta
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Cell Surface ◽  
Hematopoietic Stem Cells ◽  
Progenitor Cells ◽  
Hematopoietic Stem ◽  
Human Cd34 ◽  
Cd34 Cells ◽  
Cd34 Expression

Abstract The cell surface protein CD34 is frequently used as a marker for positive selection of human hematopoietic stem/progenitor cells in research and in transplantation. However, populations of reconstituting human and murine stem cells that lack cell surface CD34 protein have been identified. In the current studies, we demonstrate that CD34 expression is reversible on human hematopoietic stem/progenitor cells. We identified and functionally characterized a population of human CD45+/CD34− cells that was recovered from the bone marrow of immunodeficient beige/nude/xid (bnx) mice 8 to 12 months after transplantation of highly purified human bone marrow–derived CD34+/CD38− stem/progenitor cells. The human CD45+ cells were devoid of CD34 protein and mRNA when isolated from the mice. However, significantly higher numbers of human colony-forming units and long-term culture-initiating cells per engrafted human CD45+ cell were recovered from the marrow of bnx mice than from the marrow of human stem cell–engrafted nonobese diabetic/severe combined immunodeficient mice, where 24% of the human graft maintained CD34 expression. In addition to their capacity for extensive in vitro generative capacity, the human CD45+/CD34− cells recovered from thebnx bone marrow were determined to have secondary reconstitution capacity and to produce CD34+ progeny following retransplantation. These studies demonstrate that the human CD34+ population can act as a reservoir for generation of CD34− cells. In the current studies we demonstrate that human CD34+/CD38− cells can generate CD45+/CD34− progeny in a long-term xenograft model and that those CD45+/CD34− cells can regenerate CD34+ progeny following secondary transplantation. Therefore, expression of CD34 can be reversible on reconstituting human hematopoietic stem cells.

scholarly journals Integration of adeno-associated virus vectors in CD34+ human hematopoietic progenitor cells after transduction

Blood ◽  
1996 ◽  
Vol 88 (2) ◽  
pp. 492-504 ◽  
Author(s):  
G Fisher-Adams ◽  
KK Jr Wong ◽  
G Podsakoff ◽  
SJ Forman ◽  
S Chatterjee
Keyword(s):  
Gene Transfer ◽  
Progenitor Cells ◽  
Transgene Expression ◽  
Ex Vivo ◽  
Hematopoietic Progenitor Cells ◽  
Chromosomal Dna ◽  
Hematopoietic Progenitor ◽  
Adeno Associated Virus ◽  
Cd34 Cells ◽  
Vector Sequences

Gene transfer vectors based on adeno-associated virus (AAV) appear promising because of their high transduction frequencies regardless of cell cycle status and ability to integrate into chromosomal DNA. We tested AAV-mediated gene transfer into a panel of human bone marrow or umbilical cord-derived CD34+ hematopoietic progenitor cells, using vectors encoding several transgenes under the control of viral and cellular promoters. Gene transfer was evaluated by (1) chromosomal integration of vector sequences and (2) analysis of transgene expression. Southern hybridization and fluorescence in situ hybridization analysis of transduced CD34 genomic DNA showed the presence of integrated vector sequences in chromosomal DNA in a portion of transduced cells and showed that integrated vector sequences were replicated along with cellular DNA during mitosis. Transgene expression in transduced CD34 cells in suspension cultures and in myeloid colonies differentiating in vitro from transduced CD34 cells approximated that predicted by the multiplicity of transduction. This was true in CD34 cells from different donors, regardless of the transgene or selective pressure. Comparisons of CD34 cell transduction either before or after cytokine stimulation showed similar gene transfer frequencies. Our findings suggest that AAV transduction of CD34+ hematopoietic progenitor cells is efficient, can lead to stable integration in a population of transduced cells, and may therefore provide the basis for safe and efficient ex vivo gene therapy of the hematopoietic system.

Adenoviral vector–mediated gene transfer to primitive human hematopoietic progenitor cells: assessment of transduction and toxicity in long-term culture

Blood ◽  
2000 ◽  
Vol 96 (1) ◽  
pp. 100-108 ◽  
Author(s):  
Karen L. MacKenzie ◽  
Neil R. Hackett ◽  
Ronald G. Crystal ◽  
Malcolm A. S. Moore
Keyword(s):  
Gene Therapy ◽  
Gene Transfer ◽  
Progenitor Cells ◽  
Adenoviral Vector ◽  
Hematopoietic Progenitor Cells ◽  
Hematopoietic Progenitor ◽  
Long Term Culture ◽  
Cd34 Cells ◽  
Infected Cells

Adenoviral gene transfer to primitive hematopoietic progenitor cells (HPCs) would be useful in gene therapy applications where transient, high-level transgene expression is required. In the present investigations, we have used an adenoviral vector expressing the green fluorescent protein (AdGFP) to quantify transduction of primitive HPCs and assess adenoviral-associated toxicity in long-term culture. Here we show that a cytokine cocktail protects mass populations of CD34+ cells and primary colony forming unit–cultures (CFU-Cs) from toxicity, enabling transduction of up to 79% of CD34+ cells. Transduction of CFU-Cs and more primitive HPCs was quantified following fluorescence activated cell sorting for green flourescence protein expression. Our results demonstrate transduction of 45% of primary CFU-Cs, 33% of week-5 cobblestone area forming cells (CAFCs), and 18% of week-5 CFU-Cs. However, AdGFP infection inhibited proliferation of more primitive cells. Although there was no apparent quantitative change in week-5 CAFCs, the clonogenic capacity of week-5 AdGFP-infected cells was reduced by 40% (P < .01) when compared with mock-infected cells. Adenoviral toxicity specifically affected the transduced subset of primitive HPCs. Transduction of primitive cells is therefore probably underestimated by week-5 CFU-Cs and more accurately indicated by week-5 CAFCs. These studies provide the first functional and quantitative evidence of adenoviral transduction of primitive HPCs. However, further investigations will be necessary to overcome adenoviral toxicity toward primitive HPCs before adenoviral vectors can be considered a safe option for gene therapy.

Adenoviral vector–mediated gene transfer to primitive human hematopoietic progenitor cells: assessment of transduction and toxicity in long-term culture

Blood ◽  
2000 ◽  
Vol 96 (1) ◽  
pp. 100-108 ◽  
Author(s):  
Karen L. MacKenzie ◽  
Neil R. Hackett ◽  
Ronald G. Crystal ◽  
Malcolm A. S. Moore
Keyword(s):  
Gene Therapy ◽  
Gene Transfer ◽  
Progenitor Cells ◽  
Adenoviral Vector ◽  
Hematopoietic Progenitor Cells ◽  
Hematopoietic Progenitor ◽  
Long Term Culture ◽  
Cd34 Cells ◽  
Infected Cells

Abstract Adenoviral gene transfer to primitive hematopoietic progenitor cells (HPCs) would be useful in gene therapy applications where transient, high-level transgene expression is required. In the present investigations, we have used an adenoviral vector expressing the green fluorescent protein (AdGFP) to quantify transduction of primitive HPCs and assess adenoviral-associated toxicity in long-term culture. Here we show that a cytokine cocktail protects mass populations of CD34+ cells and primary colony forming unit–cultures (CFU-Cs) from toxicity, enabling transduction of up to 79% of CD34+ cells. Transduction of CFU-Cs and more primitive HPCs was quantified following fluorescence activated cell sorting for green flourescence protein expression. Our results demonstrate transduction of 45% of primary CFU-Cs, 33% of week-5 cobblestone area forming cells (CAFCs), and 18% of week-5 CFU-Cs. However, AdGFP infection inhibited proliferation of more primitive cells. Although there was no apparent quantitative change in week-5 CAFCs, the clonogenic capacity of week-5 AdGFP-infected cells was reduced by 40% (P &lt; .01) when compared with mock-infected cells. Adenoviral toxicity specifically affected the transduced subset of primitive HPCs. Transduction of primitive cells is therefore probably underestimated by week-5 CFU-Cs and more accurately indicated by week-5 CAFCs. These studies provide the first functional and quantitative evidence of adenoviral transduction of primitive HPCs. However, further investigations will be necessary to overcome adenoviral toxicity toward primitive HPCs before adenoviral vectors can be considered a safe option for gene therapy.

Stable gene transfer to human CD34+ hematopoietic cells using the Sleeping Beauty transposon

2006 ◽  
Vol 34 (10) ◽  
pp. 1333-1343 ◽  
Author(s):  
Roger P. Hollis ◽  
Sarah J. Nightingale ◽  
Xiuli Wang ◽  
Karen A. Pepper ◽  
Xiao-Jin Yu ◽  
...  
Keyword(s):  
Gene Transfer ◽  
Hematopoietic Cells ◽  
Sleeping Beauty ◽  
Stable Gene ◽  
Sleeping Beauty Transposon ◽  
Human Cd34

Stable gene transfer and expression in cord blood–derived CD34+ hematopoietic stem and progenitor cells by a hyperactive Sleeping Beauty transposon system

Blood ◽  
2009 ◽  
Vol 114 (7) ◽  
pp. 1319-1330 ◽  
Author(s):  
Xingkui Xue ◽  
Xin Huang ◽  
Sonja E. Nodland ◽  
Lajos Mátés ◽  
Linan Ma ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Gene Transfer ◽  
Cord Blood ◽  
Sleeping Beauty ◽  
Stable Gene ◽  
Hematopoietic Stem ◽  
Cd34 Cells ◽  
Nog Mice

Abstract Here we report stable gene transfer in cord blood-derived CD34+ hematopoietic stem cells using a hyperactive nonviral Sleeping Beauty (SB) transposase (SB100X). In colony-forming assays, SB100X mediated the highest efficiency (24%) of stable Discosoma sp red fluorescent protein (DsRed) reporter gene transfer in committed hematopoietic progenitors compared with both the early-generation hyperactive SB11 transposase and the piggyBac transposon system (1.23% and 3.8%, respectively). In vitro differentiation assays further demonstrated that SB100X-transfected CD34+ cells can develop into DsRed+ CD4+CD8+ T (3.17%-21.84%; median, 7.97%), CD19+ B (3.83%-18.66%; median, 7.84%), CD56+CD3− NK (3.53%-79.98%; median, 7.88%), and CD33+ myeloid (7.59%-15.63%; median, 9.48%) cells. SB100X-transfected CD34+ cells achieved approximately 46% engraftment in NOD-scid IL2γcnull (NOG) mice. Twelve weeks after transplantation, 0.57% to 28.96% (median, 2.79%) and 0.49% to 34.50% (median, 5.59%) of total human CD45+ cells in the bone marrow and spleen expressed DsRed, including CD19+ B, CD14+ monocytoid, and CD33+ myeloid cell lineages. Integration site analysis revealed SB transposon sequences in the human chromosomes of in vitro differentiated T, B, NK, and myeloid cells, as well as in human CD45+ cells isolated from bone marrow and spleen of transplanted NOG mice. Our results support the continuing development of SB-based gene transfer into human hematopoietic stem cells as a modality for gene therapy.

Gene Transfer in Hematopoietic Progenitor Cells Mediated by an SV40 Based Episomal Vector Carrying A S/MAR Element.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 5264-5264
Author(s):  
Eirini Papapetrou ◽  
Panos Ziros ◽  
Ilina Mitcheva ◽  
Aglaia Athanassiadou ◽  
Nicholas Zoumbos
Keyword(s):  
Stem Cells ◽  
Gene Transfer ◽  
Progenitor Cell ◽  
K562 Cells ◽  
Hematopoietic Progenitor Cell ◽  
Egfp Expression ◽  
Hematopoietic Progenitor ◽  
Episomal Vector ◽  
Cd34 Cells

Abstract Background/Aims: Replicating episomal vectors present a potential alternative to currently used oncoretroviral vectors for gene transfer in hematopoietic progenitor/stem cells. Their main advantage is that they can persist in the recipient nucleus as independent units, without integrating into the host’s genome, eliminating thus the risk of insertional mutagenesis. In the present study we explored the capacity of a recently developed SV40-based episomal vector, pEPI-eGFP, to stably transfect hematopoietic progenitor cell lines and primary cells, in order to evaluate its potential for therapeutic applications. pEPI-eGFP contains the enhanced green fluorescent protein (eGFP) cDNA and a Scaffold/Matrix Attachment Region (S/MAR) and it does not code for any proteins of viral origin. These unique properties qualify pEPI-eGFP as an attractive vehicle for gene therapy applications. Results: The vector was maintained as a stable episome in K562 cells for at least 100 generations and supported long-term EGFP expression, even in cells cultured in non-selective medium. Methylation-dependent cleavage assays demonstrated the vector’s ability to self-replicate in K562 cells and MEL cells, whereas its episomal status was confirmed by Southern blotting and plasmid rescue in E. coli. The vector was also maintained in primary human fibroblasts for at least 30 passages with and without selection pressure. Transfection of CD34+ cells from umbilical cord blood with pEPI-eGFP was feasible by electroporation with an efficiency of up to 30%, as estimated by flow cytometric evaluation of eGFP expression 24–48 h post-transfection. Cytokine prestimulation of CD34+ cells did not enhance transfection efficiency, whereas transfection of post-mitotic cells, such as dendritic cells was also feasible. This suggests that efficient transfection with the vector does not require cell cycling. PCR with eGFP-specific primers in single CFU colonies derived from CD34+/eGFP+/PI− FACS-sorted cells demonstrated the presence of the vector in ~20% of the colonies. Conclusion: Our results demonstrate that pEPI-2 exhibits a considerable potential as a gene transfer vector for hematopoietic cells, as it confers long-term transgene expression in hematopoietic progenitor cell lines as a stable episome and can efficiently transfect unstimulated CD34+ cells. Further studies, both in vitro and in vivo, are required to assess the long-term maintenance in hematopoietic progenitor/stem cells and their progeny as well as other features of the vector, in order to evaluate its overall efficacy and possibly improve its performance.

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