1
|
Exposure to hypomethylating agent, 5-azacytidine, may improve iCasp9 suicide gene therapy for treating GvHD in allografts. Gene Ther 2016; 23:664-72. [PMID: 27111151 DOI: 10.1038/gt.2016.39] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 03/26/2016] [Accepted: 04/07/2016] [Indexed: 02/07/2023]
Abstract
Anti-tumor cellular immunotherapies that implement a suicide gene system can limit potential undesirable effects. In a haplo-identical bone marrow transplant clinical trial, over 90% of iCaspase-9-expressing cells were eradicated after AP1903 exposure, and signs of graft-versus-host disease disappeared. Nevertheless, low numbers of genetically modified T cells survived this treatment. We studied genetically modified cell lines (GMCL) that carried a dual iCaspase-9/ΔCD19 DNA construct (ΔCD19=truncated CD19). With AP1903 exposure, a low percentage of cells (1.47±0.67%; n=5 replications) persisted in vitro. Repeated exposures to increasing AP1903 doses generated low (GMCLLR) and high AP1903-responders (GMCLHR), which expressed different levels of surface ΔCD19 and intracellular iCaspase-9. Compared with GMCLHR, GMCLLR exhibited higher methylation of 5'-long-terminal repeat (LTR) promoters, both in the number of sequences with at least one methylated CpG (16 vs 51.5%, respectively) and in the number of CpG islands (1.2 vs 8.9%, respectively). Four days of 5-azacytidine exposure reduced methylation and increased ΔCD19 and iCaspase-9 expression. Interestingly, LTR demethylation restored GMCLLR sensitivity to AP1903 by 24.3-fold (1.8 vs 43.8%) without affecting GMCLHR. We showed that 5'-LTR-methylation inhibited transgene expression and caused AP1903 hypo-responsiveness. Treating with a hypomethylating agent restored AP1903 sensitivity. This approach can be applied in further clinical trials to improve iCaspase-9 response if low response is detected.
Collapse
|
2
|
DNA methylation and histone modifications are the molecular lock in lentivirally transduced hematopoietic progenitor cells. BIOMED RESEARCH INTERNATIONAL 2015; 2015:346134. [PMID: 25961011 PMCID: PMC4417590 DOI: 10.1155/2015/346134] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 03/02/2015] [Accepted: 03/04/2015] [Indexed: 01/12/2023]
Abstract
Stable introduction of a functional gene in hematopoietic progenitor cells (HPCs) has appeared to be an alternative approach to correct genetically linked blood diseases. However, it is still unclear whether lentiviral vector (LV) is subjected to gene silencing in HPCs. Here, we show that LV carrying green fluorescent protein (GFP) reporter gene driven by cytomegalovirus (CMV) promoter was subjected to transgene silencing after transduction into HPCs. This phenomenon was not due to the deletion of proviral copy number. Study using DNA demethylating agent and histone deacetylase (HDAC) inhibitor showed that the drugs could either prevent or reverse the silencing effect. Using sodium bisulfite sequencing and chromatin immunoprecipitation (ChIP) assay, we demonstrated that DNA methylation occurred soon after LV transduction. At the highest level of gene expression, CMV promoter was acetylated and was in a euchromatin state, while GFP reporter gene was acetylated but was strangely in a heterochromatin state. When the expression declined, CMV promoter underwent transition from acetylated and euchromatic state to a heterochromatic state, while the GFP reporter gene was in deacetylated and heterochromatic state. With these, we verify that DNA methylation and dynamic histone modifications lead to transgene silencing in HPCs transduced with LV.
Collapse
|
3
|
Irradiation, cisplatin, and 5-azacytidine upregulate cytomegalovirus promoter in tumors and muscles: implementation of non-invasive fluorescence imaging. Mol Imaging Biol 2011; 13:43-52. [PMID: 20396957 PMCID: PMC3023030 DOI: 10.1007/s11307-010-0300-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Purpose The cytomegalovirus (CMV) promoter is one of the most commonly used promoters for expression of transgenes in mammalian cells. The aim of our study was to evaluate the role of methylation and upregulation of the CMV promoter by irradiation and the chemotherapeutic agent cisplatin in vivo using non-invasive fluorescence in vivo imaging. Procedures Murine fibrosarcoma LPB and mammary carcinoma TS/A cells were stably transfected with plasmids encoding CMV and p21 promoter-driven green fluorescent protein (GFP) gene. Solid TS/A tumors were induced by subcutaneous injection of fluorescent tumor cells, while leg muscles were transiently transfected with plasmid encoding GFP under the control of the CMV promoter. Cells, tumors, and legs were treated either by DNA methylation inhibitor 5-azacytidine, irradiation, or cisplatin. GFP expression was determined using a fluorescence microplate reader in vitro and by non-invasive fluorescence imaging in vivo. Results Treatment of cells, tumors, and legs with 5-azacytidine (re)activated the CMV promoter. Furthermore, treatment with irradiation or cisplatin resulted in significant upregulation of GFP expression both in vitro and in vivo. Conclusions Observed alterations in the activity of the CMV promoter limit the usefulness of this widely used promoter as a constitutive promoter. On the other hand, inducibility of CMV promoters can be beneficially used in gene therapy when combined with standard cancer treatment, such as radiotherapy and chemotherapy.
Collapse
|
4
|
Bergwerf I, De Vocht N, Tambuyzer B, Verschueren J, Reekmans K, Daans J, Ibrahimi A, Van Tendeloo V, Chatterjee S, Goossens H, Jorens PG, Baekelandt V, Ysebaert D, Van Marck E, Berneman ZN, Linden AVD, Ponsaerts P. Reporter gene-expressing bone marrow-derived stromal cells are immune-tolerated following implantation in the central nervous system of syngeneic immunocompetent mice. BMC Biotechnol 2009; 9:1. [PMID: 19128466 PMCID: PMC2630974 DOI: 10.1186/1472-6750-9-1] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2008] [Accepted: 01/07/2009] [Indexed: 01/09/2023] Open
Abstract
Background Cell transplantation is likely to become an important therapeutic tool for the treatment of various traumatic and ischemic injuries to the central nervous system (CNS). However, in many pre-clinical cell therapy studies, reporter gene-assisted imaging of cellular implants in the CNS and potential reporter gene and/or cell-based immunogenicity, still remain challenging research topics. Results In this study, we performed cell implantation experiments in the CNS of immunocompetent mice using autologous (syngeneic) luciferase-expressing bone marrow-derived stromal cells (BMSC-Luc) cultured from ROSA26-L-S-L-Luciferase transgenic mice, and BMSC-Luc genetically modified using a lentivirus encoding the enhanced green fluorescence protein (eGFP) and the puromycin resistance gene (Pac) (BMSC-Luc/eGFP/Pac). Both reporter gene-modified BMSC populations displayed high engraftment capacity in the CNS of immunocompetent mice, despite potential immunogenicity of introduced reporter proteins, as demonstrated by real-time bioluminescence imaging (BLI) and histological analysis at different time-points post-implantation. In contrast, both BMSC-Luc and BMSC-Luc/eGFP/Pac did not survive upon intramuscular cell implantation, as demonstrated by real-time BLI at different time-points post-implantation. In addition, ELISPOT analysis demonstrated the induction of IFN-γ-producing CD8+ T-cells upon intramuscular cell implantation, but not upon intracerebral cell implantation, indicating that BMSC-Luc and BMSC-Luc/eGFP/Pac are immune-tolerated in the CNS. However, in our experimental transplantation model, results also indicated that reporter gene-specific immune-reactive T-cell responses were not the main contributors to the immunological rejection of BMSC-Luc or BMSC-Luc/eGFP/Pac upon intramuscular cell implantation. Conclusion We here demonstrate that reporter gene-modified BMSC derived from ROSA26-L-S-L-Luciferase transgenic mice are immune-tolerated upon implantation in the CNS of syngeneic immunocompetent mice, providing a research model for studying survival and localisation of autologous BMSC implants in the CNS by real-time BLI and/or histological analysis in the absence of immunosuppressive therapy.
Collapse
Affiliation(s)
- Irene Bergwerf
- Laboratory of Experimental Hematology, University of Antwerp, Antwerp, Belgium.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
5
|
Ronsyn MW, Daans J, Spaepen G, Chatterjee S, Vermeulen K, D'Haese P, Van Tendeloo VF, Van Marck E, Ysebaert D, Berneman ZN, Jorens PG, Ponsaerts P. Plasmid-based genetic modification of human bone marrow-derived stromal cells: analysis of cell survival and transgene expression after transplantation in rat spinal cord. BMC Biotechnol 2007; 7:90. [PMID: 18078525 PMCID: PMC2225398 DOI: 10.1186/1472-6750-7-90] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2007] [Accepted: 12/14/2007] [Indexed: 01/09/2023] Open
Abstract
Background Bone marrow-derived stromal cells (MSC) are attractive targets for ex vivo cell and gene therapy. In this context, we investigated the feasibility of a plasmid-based strategy for genetic modification of human (h)MSC with enhanced green fluorescent protein (EGFP) and neurotrophin (NT)3. Three genetically modified hMSC lines (EGFP, NT3, NT3-EGFP) were established and used to study cell survival and transgene expression following transplantation in rat spinal cord. Results First, we demonstrate long-term survival of transplanted hMSC-EGFP cells in rat spinal cord under, but not without, appropriate immune suppression. Next, we examined the stability of EGFP or NT3 transgene expression following transplantation of hMSC-EGFP, hMSC-NT3 and hMSC-NT3-EGFP in rat spinal cord. While in vivo EGFP mRNA and protein expression by transplanted hMSC-EGFP cells was readily detectable at different time points post-transplantation, in vivo NT3 mRNA expression by hMSC-NT3 cells and in vivo EGFP protein expression by hMSC-NT3-EGFP cells was, respectively, undetectable or declined rapidly between day 1 and 7 post-transplantation. Further investigation revealed that the observed in vivo decline of EGFP protein expression by hMSC-NT3-EGFP cells: (i) was associated with a decrease in transgenic NT3-EGFP mRNA expression as suggested following laser capture micro-dissection analysis of hMSC-NT3-EGFP cell transplants at day 1 and day 7 post-transplantation, (ii) did not occur when hMSC-NT3-EGFP cells were transplanted subcutaneously, and (iii) was reversed upon re-establishment of hMSC-NT3-EGFP cell cultures at 2 weeks post-transplantation. Finally, because we observed a slowly progressing tumour growth following transplantation of all our hMSC cell transplants, we here demonstrate that omitting immune suppressive therapy is sufficient to prevent further tumour growth and to eradicate malignant xenogeneic cell transplants. Conclusion In this study, we demonstrate that genetically modified hMSC lines can survive in healthy rat spinal cord over at least 3 weeks by using adequate immune suppression and can serve as vehicles for transgene expression. However, before genetically modified hMSC can potentially be used in a clinical setting to treat spinal cord injuries, more research on standardisation of hMSC culture and genetic modification needs to be done in order to prevent tumour formation and transgene silencing in vivo.
Collapse
Affiliation(s)
- Mark W Ronsyn
- Division of Clinical Pharmacology, University of Antwerp, Antwerp, Belgium.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
6
|
Bastide C, Maroc N, Bladou F, Hassoun J, Maitland N, Mannoni P, Bagnis C. Expression of a model gene in prostate cancer cells lentivirally transduced in vitro and in vivo. Prostate Cancer Prostatic Dis 2004; 6:228-34. [PMID: 12970726 DOI: 10.1038/sj.pcan.4500668] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In a preclinical model for prostate cancer gene therapy, we have tested lentiviral vectors as a practical possibility for the transfer and long-term expression of the EGFP gene both in vitro and in vivo. The human prostate cancer cell lines DU145 and PC3 were transduced using experimental conditions which permitted analysis of the expression from a single proviral vector per cell. The transduced cells stably expressed the EGFP transgene for 4 months. After injection of the transduced cell populations into Nod-SCID mice a decrease in EGFP was only observed in a minority of cases, while the majority of tumors maintained transgene expression at in vitro levels. In vivo injection of viral vector preparations directly into pre-established subcutaneous or orthotopic tumor masses, obtained by implantation of untransduced PC3 and DU145 cells led to a high transduction efficiency. While the efficiency of direct intratumoral transduction was proportional to the dose of virus injected, the results indicated some technical limitations inherent in these approaches to prostate cancer gene therapy.
Collapse
Affiliation(s)
- C Bastide
- Institut Paoli-Calmettes, Marseille, France
| | | | | | | | | | | | | |
Collapse
|
7
|
Aubol BE, Reich NO. Murine DNA cytosine C(5)-methyltransferase: in vitro studies of de novo methylation spreading. Biochem Biophys Res Commun 2003; 310:209-14. [PMID: 14511672 DOI: 10.1016/j.bbrc.2003.08.138] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The preference of murine DNA (cytosine-5)-methyltransferase (Dnmt1) for single stranded DNA substrates is increased up to 50-fold by the presence of a proximal 5-methyl cytosine (5(me)C). This modulation is distance-dependent and is due to an enhanced binding affinity and minor changes in catalytic efficiency. No modulation was observed with double stranded DNA. Modulation requires that the 5(me)C moiety be attached to the DNA strand containing the CpG methylation target. Our results support a model in which 5(me)C binding by the enzyme occurs to at least one site outside the region involved in CpG recognition. No modulation in response to 5(me)C is observed with the bacterial enzyme M.SssI, which lacks the large N-terminal regulatory domain found in Dnmt1. We suggest that this allosteric modulation involves the N-terminal domain of Dnmt1.
Collapse
Affiliation(s)
- Brandon E Aubol
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA 93106-9510, USA
| | | |
Collapse
|
8
|
Di Ianni M, Terenzi A, Falzetti F, Bartoli A, Di Florio S, Benedetti R, Venditti G, Alfonsi D, De Ioanni M, Falini B, Tabilio A. Homing and survival of thymidine kinase-transduced human T cells in NOD/SCID mice. Cancer Gene Ther 2002; 9:756-61. [PMID: 12189525 DOI: 10.1038/sj.cgt.7700495] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2002] [Indexed: 11/09/2022]
Abstract
The herpes simplex virus thymidine kinase (HSV-tk) gene conferring ganciclovir (GCV)-specific sensitivity to transduced cells might control Graft-versus-Leukemia (GvL)/Graft-versus-Host Disease (GvHD). Human T lymphocytes were engineered with an LSN-tk retroviral vector encoding tk and neomycin resistance (NeoR) genes. A total of 80 x 10(6) tk(+) lymphocytes were injected intraperitoneally in NOD-SCID mice. Engraftment was evaluated by human CD45(+)/CD3(+) cytofluorimetric analysis and NeoR-based polymerase chain reaction (PCR) on peripheral blood, bone marrow, liver, thymus, and spleen on day +5. After 14 days, GCV (10 mg/kg daily) cytofluorimetric analysis and PCR were repeated (day +19). Immunohistological studies with anti-CD3 monoclonal antibody followed by alkaline phosphatase and monoclonal anti-alkaline phosphatase staining were performed on spleen and liver at the same time points. Human CD45(+)/CD3(+) cells were engrafted in all tissues on day +5 according to cytofluorimetry, immunohistology, and PCR. Lymphocytes "homed" to the white pulp T-cell area and to the red pulp; liver localization is prevalently at the periportal area. After GCV (day +19), cytofluorimetry and immunohistology showed very few CD3(+) cells. PCR identified the transgene in 22% tissue samples (positive only in thymus and spleen). GvHD did not occur in any animal. These data demonstrate elevated doses of human-transduced CD3(+) cells engraft in NOD/SCID mice; after GCV, very few CD3(+) cells can be detected and those that escape treatment can be found in the thymus and in the spleen on day +19. Lack of full response to GCV may account for cases of GvHD in patients receiving tk-transduced T lymphocytes.
Collapse
Affiliation(s)
- Mauro Di Ianni
- Hematology and Clinical Immunology Section, Department of Clinical and Experimental Medicine, Perugia University, Perugia, Italy
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Vitry S, Avellana-Adalid V, Lachapelle F, Baron-Van Evercooren A. Migration and multipotentiality of PSA-NCAM+ neural precursors transplanted in the developing brain. Mol Cell Neurosci 2001; 17:983-1000. [PMID: 11414788 DOI: 10.1006/mcne.2001.0987] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
By optimizing the previously described strategy for obtention of spheres enriched in PSA-NCAM+ precursors, we prepared PSA-NCAM-immunoselected cell populations from cerebral hemispheres of neonatal MBP-LacZ transgenic mice. These cells expressed Nestin, exhibited clonal expansion potential and formed spheres, which were initially enriched in PSA-NCAM+ cells but became enriched in GD3+ oligodendrocyte progenitors after 1 week in B104 contionned medium. One month after their periventricular transplantation into the brain of wild-type and/or shiverer newborn mice, cells from PSA-NCAM+ spheres exhibited a higher rostral migration potential than cells from GD3+ spheres, and clearly contributed to myelination in the olfactory bulb. In shiverer hosts, both sphere populations generated oligodendrocytes with similar myelination potential. In addition PSA-NCAM+ sphere cells generated GFAP+ astrocytes and NeuN+ neurons, depending on their site of insertion. These results evidence the high plasticity of newborn PSA-NCAM+ neural precursors and suggest that they are promising tools for cell therapy of CNS diseases, including myelin disorders.
Collapse
Affiliation(s)
- S Vitry
- Institut National de la Santé et de la Recherche Médicale U546, CHU Pitié-Salpêtrière, Paris cedex 13, 75634, France
| | | | | | | |
Collapse
|
10
|
Di Ianni M, Terenzi A, Di Florio S, Venditti G, Benedetti R, Santucci A, Bartoli A, Fettucciari K, Marconi P, Rossi R, Martelli MF, Tabilio A. In vivo demethylation of a MoMuLV retroviral vector expressing the herpes simplex thymidine kinase suicide gene by 5' azacytidine. Stem Cells 2001; 18:415-21. [PMID: 11072029 DOI: 10.1634/stemcells.18-6-415] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We constructed a functional MoMuLV-based bicistronic retroviral vector encoding the herpes simplex virus type I thymidine kinase gene, which induces sensitivity to the prodrug ganciclovir (gcv), and the reporter beta-galactosidase gene (MFG-tk-IRES-lacZ). The U937 histiocytic cell line was transduced with this vector, and a clone (VB71) with high-level transgene expression was selected. Severe combined immunodeficient (SCID) mice were injected with VB71 cells to evaluate the role of long terminal repeat methylation in transgene silencing in vivo and to see whether 5-azacytidine (5' aza-C) demethylating agent prevented it. We found 5' aza-C maintained gene expression at high level in vitro. In vivo, time to tumor onset was significantly longer in SCID mice receiving the VB71 cells, 5' aza-C, and gcv compared with animals treated with either 5' aza-C or gcv alone. The number of injected tumor cells influences tumor onset time and the efficacy of 5' aza-C and gcv treatment. The standard gcv treatment schedule (10 mg/kg from d + 1 until the onset of tumor) controlled tumor onset better than short-term treatment with high doses. In conclusion, the results extend our previous findings that transgene methylation in vivo may be prevented with an appropriate schedule of 5' aza-C and gcv.
Collapse
Affiliation(s)
- M Di Ianni
- Haematology and Clinical Immunology and Pathology Sections, Department of Clinical and Experimental Medicine, Perugia University, Perugia, Italy
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Sarkis C, Serguera C, Petres S, Buchet D, Ridet JL, Edelman L, Mallet J. Efficient transduction of neural cells in vitro and in vivo by a baculovirus-derived vector. Proc Natl Acad Sci U S A 2000; 97:14638-43. [PMID: 11114190 PMCID: PMC18971 DOI: 10.1073/pnas.260472897] [Citation(s) in RCA: 128] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Gene delivery to the central nervous system is central to the development of gene therapy for neurological diseases. We developed a baculovirus-derived vector, the Bac-CMV-GFP vector, containing a reporter gene encoding for the green fluorescent protein (GFP) under the control of the cytomegalovirus (CMV) promoter. Two neuroblastomal cell lines and three human primary neural cultures could be efficiently transduced. In all cases, addition of butyrate, an inhibitor of histone deacetylase, increased the level of expression in terms of the number of GFP-expressing cells and the intensity of fluorescence. The level of expression in a human telencephalic culture was over 50% of transduced cells with a multiplicity of infection of 25. GFP expression was demonstrated to be genuine expression and not pseudotransduction of the reporter protein. Most interestingly, Bac-CMV-GFP could transduce neural cells in vivo when directly injected into the brain of rodents and was not inactivated by the complement system. Thus, baculovirus is a promising tool for gene transfer into the central nervous system both for studies of the function of foreign genes and the development of gene therapy strategies.
Collapse
Affiliation(s)
- C Sarkis
- Laboratoire de Génétique Moléculaire des Processus Neurodégénératifs et de la Neurotransmission, Unité Mixte de Recherche 9923, Centre National de la Recherche Scientifique, H opital de la Pitié-Salpétriêre, Paris, France
| | | | | | | | | | | | | |
Collapse
|
12
|
Di Ianni M, Di Florio S, Venditti G, Falzetti F, Mannoni P, Martelli MF, Tabilio A. T lymphocyte transduction with herpes simplex virus-thymidine kinase (HSV-tk) gene: comparison of four different infection protocols. JOURNAL OF HEMATOTHERAPY & STEM CELL RESEARCH 1999; 8:645-52. [PMID: 10645772 DOI: 10.1089/152581699319812] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
In this study, we assessed the efficiency of T lymphocyte transduction with a retroviral vector carrying the herpes simplex virus thymidine kinase (HSV-tk) and neomycin phosphotransferase (neo) genes by four different protocols: standard supernatant infection, supernatant infection plus centrifugation steps, supernatant infection on fibronectin fragment-coated wells, and cocultivation. After retrovirus-mediated gene transfer of tk-neo in PHA/IL-2-stimulated primary T lymphocytes and G418 selection, T cells retained their proliferative activity, alloresponsiveness, ability to produce and to respond to IL-2, and ganciclovir (gcv)-specific sensitivity. When the four different transduction techniques were compared, no significant differences were seen in terms of cellular viability, proliferation capacity, and immunophenotyping. tk gene expression was the same in all transduced selected populations, as indicated by gcv sensitivity. Transduction efficiency was evaluated by semiquantitative PCR. Using the standard supernatant infection method, the rate of infection was extremely low (<5%). After adding the centrifugation step or performing supernatant infection on fibronectin fragment-coated wells, PCR analysis showed a 30%-40% rate of transduced cells. After infection by cocultivation, the rate of transduced cells was 30%-40%. These results demonstrate that supernatant infection plus centrifugation, supernatant infection on fibronectin fragment-coated wells, and cocultivation methods provide equivalent rates of transduced cells. The lack of reproducibility and safety indicates that cocultivation is not suitable for clinical studies. In our view, supernatant infection plus centrifugation is easier to perform than using fibronectin fragments, and it is currently the optimal method for clinical studies when large quantities of T lymphocytes are being processed.
Collapse
Affiliation(s)
- M Di Ianni
- Department of Clinical and Experimental Medicine, Perugia University, Italy
| | | | | | | | | | | | | |
Collapse
|
13
|
Abstract
Abstract
—We developed a murine model of arterial gene transfer and used it to test the role of antigen-specific immunity in the loss of adenovirus-mediated transgene expression. Adenoviral vectors encoding either β-galactosidase (β-gal) or green fluorescent protein were infused to the lumen of normal common carotids of CD-1 and C57BL/6 mice and atherosclerotic carotids of
Apoe
−/−
mice. At 3 days after gene transfer, significant reporter gene expression was detected in all strains. Transgene expression was transient, with expression undetectable at 14 days. Next, a β-gal–expressing vector was infused into carotids of ROSA26 mice (transgenic for, and therefore tolerant of, β-gal) and RAG-2
−/−
mice (deficient in recombinase-activating gene [RAG]-2 and therefore lacking in antigen-specific immunity). β-Gal expression was again high at 3 days but declined substantially (>90%) by 14 days. In vivo labeling with bromodeoxyuridine revealed that carotid endothelial proliferation was increased dramatically by the gene-transfer procedure alone, likely leading to the loss of episomal adenoviral DNA. Gene transfer to normal and atherosclerotic mouse carotids can be accomplished; however, elimination of antigen-specific immune responses does not prevent the early loss of adenovirus-mediated transgene expression. Efforts to prolong adenovirus-mediated transgene expression in the artery wall must be redirected. These efforts will likely include strategies to avoid the consequences of increased cell turnover. Nevertheless, despite the brevity of expression, this mouse model of gene transfer to normal and severely atherosclerotic arteries will likely be useful for investigating the genetic basis of vascular disease and for developing gene therapies. The full text of this article is available at http://www.circresaha.org.
Collapse
Affiliation(s)
- Giuseppe Vassalli
- From the Gladstone Institute of Cardiovascular Disease (G.V., R.A., R.Q., C.A., D.A.D.), Daiichi Research Center (G.V., D.A.D.), and Department of Medicine (R.A., R.Q., D.A.D.), University of California, San Francisco, Calif
| | - Ramtin Agah
- From the Gladstone Institute of Cardiovascular Disease (G.V., R.A., R.Q., C.A., D.A.D.), Daiichi Research Center (G.V., D.A.D.), and Department of Medicine (R.A., R.Q., D.A.D.), University of California, San Francisco, Calif
| | - Renli Qiao
- From the Gladstone Institute of Cardiovascular Disease (G.V., R.A., R.Q., C.A., D.A.D.), Daiichi Research Center (G.V., D.A.D.), and Department of Medicine (R.A., R.Q., D.A.D.), University of California, San Francisco, Calif
| | - Christina Aguilar
- From the Gladstone Institute of Cardiovascular Disease (G.V., R.A., R.Q., C.A., D.A.D.), Daiichi Research Center (G.V., D.A.D.), and Department of Medicine (R.A., R.Q., D.A.D.), University of California, San Francisco, Calif
| | - David A. Dichek
- From the Gladstone Institute of Cardiovascular Disease (G.V., R.A., R.Q., C.A., D.A.D.), Daiichi Research Center (G.V., D.A.D.), and Department of Medicine (R.A., R.Q., D.A.D.), University of California, San Francisco, Calif
| |
Collapse
|