1
|
Lightner AL, Reese JS, Ream J, Nachand D, Dadgar N, Adams A, VanDenBossche A, Pineiro AO, Hull T. A phase IB/IIA study of ex vivo expanded allogeneic bone marrow-derived mesenchymal stem cells for the treatment of rectovaginal fistulizing Crohn's disease. Surgery 2024; 175:242-249. [PMID: 37661485 DOI: 10.1016/j.surg.2023.07.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 07/13/2023] [Accepted: 07/18/2023] [Indexed: 09/05/2023]
Abstract
BACKGROUND Crohn-related rectovaginal fistulas are notoriously difficult to treat. Studies of mesenchymal stem cells for the treatment of perianal Crohn fistulizing disease have largely excluded rectovaginal fistulas. The aim of this study was to determine the safety and efficacy of mesenchymal stem cells for refractory rectovaginal fistulizing Crohn disease. METHODS A phase IB/IIA randomized control trial was performed in a 3:1, single-blinded study. Patients included were adult women with an anovaginal/rectovaginal fistula in the setting of Crohn disease. Seventy-five million mesenchymal stem cells were administered with a 22G needle after curettage and primary closure of the fistula tract at day 0 and month 3. Adverse and serious adverse events were recorded at post-procedure day 1, week 2, week 6, month 3, month 6, and month 12, along with clinical healing, magnetic resonance imaging, and patient-reported outcomes. RESULTS A total of 19 patients were enrolled and treated-15 treatment and 4 control. There were no adverse or serious adverse events related to mesenchymal stem cell therapy. At 6 months, 50% of the treatment group and 0% of the control had complete clinical and radiographic healing; 91.7% of the treatment group had improvement at 6 months with only one patient having a lack of response, whereas only 50% of the control group had improvement at 6 months. CONCLUSION Bone marrow-derived mesenchymal stem cells offer a safe alternative treatment approach for rectovaginal fistulas in the setting of Crohn disease. Complete healing was achieved in half of the patients.
Collapse
Affiliation(s)
- Amy L Lightner
- Department of Colorectal Surgery, Digestive Disease Surgical Institute, Cleveland Clinic, OH; Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, OH.
| | - Jane S Reese
- Case Western Reserve University National Center for Regenerative Medicine, Cleveland, OH
| | - Justin Ream
- Department of Abdominal Radiology, Digestive Disease Surgical Institute, Cleveland Clinic, OH
| | - Douglas Nachand
- Department of Abdominal Radiology, Digestive Disease Surgical Institute, Cleveland Clinic, OH
| | - Neda Dadgar
- Department of Colorectal Surgery, Digestive Disease Surgical Institute, Cleveland Clinic, OH; Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, OH
| | - Ashley Adams
- Department of Colorectal Surgery, Digestive Disease Surgical Institute, Cleveland Clinic, OH
| | - Alexandra VanDenBossche
- Department of Colorectal Surgery, Digestive Disease Surgical Institute, Cleveland Clinic, OH
| | - Ana Otero Pineiro
- Department of Colorectal Surgery, Digestive Disease Surgical Institute, Cleveland Clinic, OH
| | - Tracy Hull
- Department of Colorectal Surgery, Digestive Disease Surgical Institute, Cleveland Clinic, OH
| |
Collapse
|
2
|
Anthony-Gonda K, Ray A, Su H, Wang Y, Xiong Y, Lee D, Block A, Chilunda V, Weiselberg J, Zemelko L, Wang YY, Kleinsorge-Block S, Reese JS, de Lima M, Ochsenbauer C, Kappes JC, Dimitrov DS, Orentas R, Deeks SG, Rutishauser RL, Berman JW, Goldstein H, Dropulić B. In vivo killing of primary HIV-infected cells by peripheral-injected early memory-enriched anti-HIV duoCAR T cells. JCI Insight 2022; 7:e161698. [PMID: 36345941 PMCID: PMC9675454 DOI: 10.1172/jci.insight.161698] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 09/14/2022] [Indexed: 11/09/2022] Open
Abstract
HIV-specific chimeric antigen receptor-T cell (CAR T cell) therapies are candidates to functionally cure HIV infection in people with HIV (PWH) by eliminating reactivated HIV-infected cells derived from latently infected cells within the HIV reservoir. Paramount to translating such therapeutic candidates successfully into the clinic will require anti-HIV CAR T cells to localize to lymphoid tissues in the body and eliminate reactivated HIV-infected cells such as CD4+ T cells and monocytes/macrophages. Here we show that i.v. injected anti-HIV duoCAR T cells, generated using a clinical-grade anti-HIV duoCAR lentiviral vector, localized to the site of active HIV infection in the spleen of humanized mice and eliminated HIV-infected PBMCs. CyTOF analysis of preinfusion duoCAR T cells revealed an early memory phenotype composed predominantly of CCR7+ stem cell-like/central memory T cells (TSCM/TCM) with expression of some effector-like molecules. In addition, we show that anti-HIV duoCAR T cells effectively sense and kill HIV-infected CD4+ T cells and monocytes/macrophages. Furthermore, we demonstrate efficient genetic modification of T cells from PWH on suppressive ART into anti-HIV duoCAR T cells that subsequently kill autologous PBMCs superinfected with HIV. These studies support the safety and efficacy of anti-HIV duoCAR T cell therapy in our presently open phase I/IIa clinical trial (NCT04648046).
Collapse
Affiliation(s)
- Kim Anthony-Gonda
- Caring Cross, Gaithersburg, Maryland, USA
- Lentigen, a Miltenyi Biotec Company, Gaithersburg, Maryland, USA
| | - Alex Ray
- Department of Microbiology & Immunology and
| | - Hang Su
- Department of Microbiology & Immunology and
| | - Yuge Wang
- Lentigen, a Miltenyi Biotec Company, Gaithersburg, Maryland, USA
| | - Ying Xiong
- Caring Cross, Gaithersburg, Maryland, USA
- Lentigen, a Miltenyi Biotec Company, Gaithersburg, Maryland, USA
| | - Danica Lee
- Department of Microbiology & Immunology and
| | | | - Vanessa Chilunda
- Department of Pathology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Jessica Weiselberg
- Department of Pathology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Lily Zemelko
- Department of Medicine, UCSF, San Francisco, California, USA
| | - Yen Y. Wang
- Department of Medicine, UCSF, San Francisco, California, USA
| | - Sarah Kleinsorge-Block
- Stem Cell Transplant Program and Center for Regenerative Medicine, University Hospitals Seidman Cancer Center and Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
| | - Jane S. Reese
- Stem Cell Transplant Program and Center for Regenerative Medicine, University Hospitals Seidman Cancer Center and Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
| | - Marcos de Lima
- Stem Cell Transplant Program and Center for Regenerative Medicine, University Hospitals Seidman Cancer Center and Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
| | - Christina Ochsenbauer
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - John C. Kappes
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
- Birmingham Veterans Affairs Medical Center, Research Service, Birmingham, Alabama, USA
| | - Dimiter S. Dimitrov
- Center for Antibody Therapeutics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Rimas Orentas
- Caring Cross, Gaithersburg, Maryland, USA
- Department of Pediatrics, University of Washington School of Medicine, and Ben Towne Center for Childhood Cancer Research, Seattle Children’s Research lnstitute, Seattle, Washington, USA
| | - Steven G. Deeks
- Department of Medicine, UCSF, San Francisco, California, USA
| | | | - Joan W. Berman
- Department of Microbiology & Immunology and
- Department of Pathology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Harris Goldstein
- Department of Microbiology & Immunology and
- Department of Pediatrics, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Boro Dropulić
- Caring Cross, Gaithersburg, Maryland, USA
- Lentigen, a Miltenyi Biotec Company, Gaithersburg, Maryland, USA
| |
Collapse
|
3
|
Jackson Z, Hong C, Schauner R, Dropulic B, Caimi PF, de Lima M, Giraudo MF, Gupta K, Reese JS, Hwang TH, Wald DN. Sequential Single-Cell Transcriptional and Protein Marker Profiling Reveals TIGIT as a Marker of CD19 CAR-T Cell Dysfunction in Patients with Non-Hodgkin Lymphoma. Cancer Discov 2022; 12:1886-1903. [PMID: 35554512 PMCID: PMC9357057 DOI: 10.1158/2159-8290.cd-21-1586] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 03/02/2022] [Accepted: 05/04/2022] [Indexed: 02/07/2023]
Abstract
Chimeric antigen receptor T-cell (CAR-T cell) therapy directed at CD19 produces durable remissions in the treatment of relapsed/refractory non-Hodgkin lymphoma (NHL). Nonetheless, many patients receiving CD19 CAR-T cells fail to respond for unknown reasons. To reveal changes in 4-1BB-based CD19 CAR-T cells and identify biomarkers of response, we used single-cell RNA sequencing and protein surface marker profiling of patient CAR-T cells pre- and postinfusion into patients with NHL. At the transcriptional and protein levels, we note the evolution of CAR-T cells toward a nonproliferative, highly differentiated, and exhausted state, with an enriched exhaustion profile in CAR-T cells of patients with poor response marked by TIGIT expression. Utilizing in vitro and in vivo studies, we demonstrate that TIGIT blockade alone improves the antitumor function of CAR-T cells. Altogether, we provide evidence of CAR-T cell dysfunction marked by TIGIT expression driving a poor response in patients with NHL. SIGNIFICANCE This is the first study investigating the mechanisms linked to CAR-T patient responses based on the sequential analysis of manufactured and infused CAR-T cells using single-cell RNA and protein expression data. Furthermore, our findings are the first to demonstrate an improvement of CAR-T cell efficacy with TIGIT inhibition alone. This article is highlighted in the In This Issue feature, p. 1825.
Collapse
Affiliation(s)
- Zachary Jackson
- Department of Pathology, Case Western Reserve University, Cleveland, Ohio, USA
| | - Changjin Hong
- Department of Artificial Intelligence and Informatics, Mayo Clinic, Jacksonville, Florida, USA
| | - Robert Schauner
- Department of Pathology, Case Western Reserve University, Cleveland, Ohio, USA
| | | | - Paolo F. Caimi
- Department of Medicine, University Hospitals Cleveland Medical Center, Cleveland, Ohio, USA
| | | | | | - Kalpana Gupta
- Department of Pathology, Case Western Reserve University, Cleveland, Ohio, USA
| | - Jane S. Reese
- Stem Cell Transplantation Program, University Hospitals Seidman Cancer Center, Cleveland, Ohio, USA
| | - Tae Hyun Hwang
- Department of Artificial Intelligence and Informatics, Mayo Clinic, Jacksonville, Florida, USA.,Department of Immunology, Mayo Clinic, Jacksonville, Florida, USA
| | - David N. Wald
- Department of Pathology, Case Western Reserve University, Cleveland, Ohio, USA.,Department of Pathology, University Hospitals Cleveland Medical Center, Cleveland, Ohio, USA.,Louis Stokes Cleveland VA Medical Center, Department of Pathology, Cleveland, Ohio, USA
| |
Collapse
|
4
|
Chung DJ, Shah N, Stroopinsky D, Wu J(M, Bisharat L, Callander NS, Logan B, Anderson KC, Dhakal B, Devine SM, Efebera Y, Geller N, Hematti P, Holmberg LA, Howard A, Johnson BD, Lazarus HM, Malek E, McCarthy PL, McKenna DH, Mendizabal A, Munshi NC, O’Donnell LC, Rapoport AP, Nooka A, Reese JS, Soiffer RJ, Uhl L, Cheloni G, Karagkouni D, Vlachos I, Young J, Rosenblatt J, Waller EK, Pasquini MC, Avigan DE. Dendritic Cell/Multiple Myeloma (MM) Fusion Vaccine with Lenalidomide Maintenance after Autologous Hematopoietic Cell Transplant (HCT) Induces MM-Specific Immunity, BMT CTN 1401. Transplant Cell Ther 2022. [DOI: 10.1016/s2666-6367(22)00443-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
5
|
Manjappa S, Fox R, Caimi P, Reese JS, de Lima M, Malek E. Impact of Daratumumab on Stem Cell Collection, Graft Composition and Engraftment. Transplant Cell Ther 2021. [DOI: 10.1016/s2666-6367(21)00602-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
6
|
Jackson Z, Roe A, Sharma AA, Lopes FBTP, Talla A, Kleinsorge-Block S, Zamborsky K, Schiavone J, Manjappa S, Schauner R, Lee G, Liu R, Caimi PF, Xiong Y, Krueger W, Worden A, Kadan M, Schneider D, Orentas R, Dropulic B, Sekaly RP, de Lima M, Wald DN, Reese JS. Automated Manufacture of Autologous CD19 CAR-T Cells for Treatment of Non-hodgkin Lymphoma. Front Immunol 2020; 11:1941. [PMID: 32849651 PMCID: PMC7427107 DOI: 10.3389/fimmu.2020.01941] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 07/17/2020] [Indexed: 01/26/2023] Open
Abstract
Chimeric antigen receptor T cells (CAR-T cell) targeting CD19 are effective against several subtypes of CD19-expressing hematologic malignancies. Centralized manufacturing has allowed rapid expansion of this cellular therapy, but it may be associated with treatment delays due to the required logistics. We hypothesized that point of care manufacturing of CAR-T cells on the automated CliniMACS Prodigy® device allows reproducible and fast delivery of cells for the treatment of patients with non-Hodgkin lymphoma. Here we describe cell manufacturing results and characterize the phenotype and effector function of CAR-T cells used in a phase I/II study. We utilized a lentiviral vector delivering a second-generation CD19 CAR construct with 4-1BB costimulatory domain and TNFRSF19 transmembrane domain. Our data highlight the successful generation of CAR-T cells at numbers sufficient for all patients treated, a shortened duration of production from 12 to 8 days followed by fresh infusion into patients, and the detection of CAR-T cells in patient circulation up to 1-year post-infusion.
Collapse
MESH Headings
- Animals
- Antigens, CD19/genetics
- Antigens, CD19/immunology
- Antigens, CD19/metabolism
- Automation
- Cell Culture Techniques
- Cell Engineering
- Cells, Cultured
- Clinical Trials, Phase I as Topic
- Clinical Trials, Phase II as Topic
- Cytotoxicity, Immunologic
- Humans
- Immunotherapy, Adoptive
- Lymphoma, Non-Hodgkin/immunology
- Lymphoma, Non-Hodgkin/metabolism
- Lymphoma, Non-Hodgkin/therapy
- Mice, Inbred NOD
- Phenotype
- Point-of-Care Systems
- Receptors, Chimeric Antigen/genetics
- Receptors, Chimeric Antigen/immunology
- Receptors, Chimeric Antigen/metabolism
- T-Lymphocytes/immunology
- T-Lymphocytes/metabolism
- T-Lymphocytes/transplantation
- Transplantation, Autologous
- Treatment Outcome
- Workload
- Xenograft Model Antitumor Assays
Collapse
Affiliation(s)
- Zachary Jackson
- Department of Pathology, Case Western Reserve University, Cleveland, OH, United States
| | - Anne Roe
- Department of Pathology, Case Western Reserve University, Cleveland, OH, United States
| | | | | | - Aarthi Talla
- The Alan Turing Institute, British Library, London, United Kingdom
| | - Sarah Kleinsorge-Block
- Stem Cell Transplantation Program, University Hospitals Seidman Cancer Center, Cleveland, OH, United States
| | - Kayla Zamborsky
- Stem Cell Transplantation Program, University Hospitals Seidman Cancer Center, Cleveland, OH, United States
| | - Jennifer Schiavone
- Stem Cell Transplantation Program, University Hospitals Seidman Cancer Center, Cleveland, OH, United States
| | - Shivaprasad Manjappa
- Department of Medicine, University Hospitals Cleveland Medical Center, Cleveland, OH, United States
| | - Robert Schauner
- Department of Pathology, Case Western Reserve University, Cleveland, OH, United States
| | - Grace Lee
- Department of Pathology, Case Western Reserve University, Cleveland, OH, United States
| | - Ruifu Liu
- Department of Pathology, Case Western Reserve University, Cleveland, OH, United States
| | - Paolo F. Caimi
- Stem Cell Transplantation Program, University Hospitals Seidman Cancer Center, Cleveland, OH, United States
- Department of Medicine, University Hospitals Cleveland Medical Center, Cleveland, OH, United States
| | - Ying Xiong
- Lentigen Technology, Inc., a Miltenyi Biotec Company, Gaithersburg, MD, United States
| | - Winfried Krueger
- Lentigen Technology, Inc., a Miltenyi Biotec Company, Gaithersburg, MD, United States
| | - Andrew Worden
- Lentigen Technology, Inc., a Miltenyi Biotec Company, Gaithersburg, MD, United States
| | - Mike Kadan
- Lentigen Technology, Inc., a Miltenyi Biotec Company, Gaithersburg, MD, United States
| | - Dina Schneider
- Lentigen Technology, Inc., a Miltenyi Biotec Company, Gaithersburg, MD, United States
| | - Rimas Orentas
- Department of Pediatrics, Seattle Children’s Research Institute, Seattle, WA, United States
- Department of Pediatrics, University of Washington School of Medicine, Seattle, WA, United States
| | - Boro Dropulic
- Lentigen Technology, Inc., a Miltenyi Biotec Company, Gaithersburg, MD, United States
| | - Rafick-Pierre Sekaly
- Department of Pathology, Case Western Reserve University, Cleveland, OH, United States
| | - Marcos de Lima
- Stem Cell Transplantation Program, University Hospitals Seidman Cancer Center, Cleveland, OH, United States
- Department of Medicine, University Hospitals Cleveland Medical Center, Cleveland, OH, United States
| | - David N. Wald
- Department of Pathology, Case Western Reserve University, Cleveland, OH, United States
- Department of Pathology, University Hospitals Cleveland Medical Center, Cleveland, OH, United States
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH, United States
| | - Jane S. Reese
- Stem Cell Transplantation Program, University Hospitals Seidman Cancer Center, Cleveland, OH, United States
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH, United States
| |
Collapse
|
7
|
Caimi P, Reese JS, Otegbeye F, Schneider D, Bakalarz KL, Boughan KM, Cooper B, Galloway E, Gallogly M, Kruger W, Worden A, Kadan M, Lopes FBTP, Sharma A, Malek E, Metheny L, Tomlinson B, Wald D, Sekaly RP, Orentas R, Dropulic B, de Lima M. On Site Manufacture of AntiCD19 CAR-T Cells. Responses in Subjects with Rapidly Progressive Refractory Lymphomas. Biol Blood Marrow Transplant 2020. [DOI: 10.1016/j.bbmt.2019.12.478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
8
|
Ahmed N, Caimi P, Reese JS, Otegbeye F, Patel S, Schneider D, Boughan KM, Cooper B, Gallogly M, Kruger W, Worden A, Kadan M, Lopes FBTP, Sharma A, Malek E, Metheny L, Tomlinson B, Wald D, Sekaly RP, Orentas R, Dropulic B, de Lima M. Prophylactic Tocilizumab in Patients with Relapsed Refractory Lymphoma Treated with Anti CD19 Chimeric Antigen Receptor T-Cell Therapy. Biol Blood Marrow Transplant 2020. [DOI: 10.1016/j.bbmt.2019.12.447] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
9
|
Rozenberg A, Rezk A, Boivin MN, Darlington PJ, Nyirenda M, Li R, Jalili F, Winer R, Artsy EA, Uccelli A, Reese JS, Planchon SM, Cohen JA, Bar-Or A. Human Mesenchymal Stem Cells Impact Th17 and Th1 Responses Through a Prostaglandin E2 and Myeloid-Dependent Mechanism. Stem Cells Transl Med 2016; 5:1506-1514. [PMID: 27400792 PMCID: PMC5070498 DOI: 10.5966/sctm.2015-0243] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Accepted: 05/02/2016] [Indexed: 12/13/2022] Open
Abstract
: Human mesenchymal stem cells (hMSCs) are being increasingly pursued as potential therapies for immune-mediated conditions, including multiple sclerosis. Although they can suppress human Th1 responses, they reportedly can reciprocally enhance human Th17 responses. Here, we investigated the mechanisms underlying the capacity of hMSCs to modulate human Th1 and Th17 responses. Human adult bone marrow-derived MSCs were isolated, and their purity and differentiation capacity were confirmed. Human venous peripheral blood mononuclear cells (PBMC) were activated, alone, together with hMSC, or in the presence of hMSC-derived supernatants (sups). Cytokine expression by CD4+ T-cell subsets (intracellular staining by fluorescence-activated cell sorting) and secreted cytokines (enzyme-linked immunosorbent assay) were then quantified. The contribution of prostaglandin E2 (PGE2) as well as of myeloid cells to the hMSC-mediated regulation of T-cell responses was investigated by selective depletion of PGE2 from the hMSC sups (anti-PGE2 beads) and by the selective removal of CD14+ cells from the PBMC (magnetic-activated cell sorting separation). Human MSC-secreted products could reciprocally induce interleukin-17 expression while decreasing interferon-γ expression by human CD4+ T cells, both in coculture and through soluble products. Pre-exposure of hMSCs to IL-1β accentuated their capacity to reciprocally regulate Th1 and Th17 responses. Human MSCs secreted high levels of PGE2, which correlated with their capacity to regulate the T-cell responses. Selective removal of PGE2 from the hMSC supernatants abrogated the impact of hMSC on the T cells. Selective removal of CD14+ cells from the PBMCs also limited the capacity of hMSC-secreted PGE2 to affect T-cell responses. Our discovery of a novel PGE2-dependent and myeloid cell-mediated mechanism by which human MSCs can reciprocally induce human Th17 while suppressing Th1 responses has implications for the use of, as well as monitoring of, MSCs as a potential therapeutic for patients with multiple sclerosis and other immune-mediated diseases. SIGNIFICANCE Although animal studies have generated a growing interest in the anti-inflammatory potential of mesenchymal stem cells (MSCs) for the treatment of autoimmune diseases, MSCs possess the capacity to both limit and promote immune responses. Yet relatively little is known about human-MSC modulation of human disease-implicated T-cell responses, or the mechanisms underlying such modulation. The current study reveals a novel prostaglandin E2-dependent and myeloid cell-mediated mechanism by which human MSCs can reciprocally regulate human Th17 and Th1 responses, with implications for the use of MSCs as a potential therapeutic for patients with multiple sclerosis and other immune-mediated diseases.
Collapse
Affiliation(s)
- Ayal Rozenberg
- Neuroimmunology Unit, Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada
- Neuroimmunology Unit, Rambam Medical Center, Haifa, Israel
| | - Ayman Rezk
- Neuroimmunology Unit, Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada
| | - Marie-Noëlle Boivin
- Neuroimmunology Unit, Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada
| | - Peter J Darlington
- Department of Exercise Science, Concordia University, Montreal, Quebec, Canada
| | - Mukanthu Nyirenda
- Neuroimmunology Unit, Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada
| | - Rui Li
- Neuroimmunology Unit, Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada
| | - Farzaneh Jalili
- Neuroimmunology Unit, Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada
| | - Raz Winer
- Neuroimmunology Unit, Rambam Medical Center, Haifa, Israel
| | - Elinor A Artsy
- American Medical Students Program, Technion Institute of Technology, Haifa, Israel
| | - Antonio Uccelli
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, and Maternal and Child Health, University of Genoa, Genova, Italy
- Center of Excellence for Biomedical Research, University of Genoa, Genova, Italy
| | - Jane S Reese
- National Center for Regenerative Medicine, Case Western Reserve University, and University Hospitals Seidman Cancer Center, Cleveland, Ohio, USA
| | - Sarah M Planchon
- Mellen Center for Multiple Sclerosis Treatment and Research, Neurological Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Jeffrey A Cohen
- Mellen Center for Multiple Sclerosis Treatment and Research, Neurological Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Amit Bar-Or
- Neuroimmunology Unit, Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada
- Experimental Therapeutics Program, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| |
Collapse
|
10
|
Roth JC, Alberti MO, Ismail M, Lingas KT, Reese JS, Gerson SL. MGMT enrichment and second gene co-expression in hematopoietic progenitor cells using separate or dual-gene lentiviral vectors. Virus Res 2014; 196:170-80. [PMID: 25479595 DOI: 10.1016/j.virusres.2014.11.027] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Revised: 11/20/2014] [Accepted: 11/25/2014] [Indexed: 12/21/2022]
Abstract
The DNA repair gene O(6)-methylguanine-DNA methyltransferase (MGMT) allows efficient in vivo enrichment of transduced hematopoietic stem cells (HSC). Thus, linking this selection strategy to therapeutic gene expression offers the potential to reconstitute diseased hematopoietic tissue with gene-corrected cells. However, different dual-gene expression vector strategies are limited by poor expression of one or both transgenes. To evaluate different co-expression strategies in the context of MGMT-mediated HSC enrichment, we compared selection and expression efficacies in cells cotransduced with separate single-gene MGMT and GFP lentivectors to those obtained with dual-gene vectors employing either encephalomyocarditis virus (EMCV) internal ribosome entry site (IRES) or foot and mouth disease virus (FMDV) 2A elements for co-expression strategies. Each strategy was evaluated in vitro and in vivo using equivalent multiplicities of infection (MOI) to transduce 5-fluorouracil (5-FU) or Lin(-)Sca-1(+)c-kit(+) (LSK)-enriched murine bone marrow cells (BMCs). The highest dual-gene expression (MGMT(+)GFP(+)) percentages were obtained with the FMDV-2A dual-gene vector, but half of the resulting gene products existed as fusion proteins. Following selection, dual-gene expression percentages in single-gene vector cotransduced and dual-gene vector transduced populations were similar. Equivalent MGMT expression levels were obtained with each strategy, but GFP expression levels derived from the IRES dual-gene vector were significantly lower. In mice, vector-insertion averages were similar among cells enriched after dual-gene vectors and those cotransduced with single-gene vectors. These data demonstrate the limitations and advantages of each strategy in the context of MGMT-mediated selection, and may provide insights into vector design with respect to a particular therapeutic gene or hematologic defect.
Collapse
Affiliation(s)
- Justin C Roth
- Molecular Virology Training Program, Case Western Reserve University, Cleveland, OH, USA; Division of Hematology and Oncology, Department of Medicine, Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH, USA; Division of Pediatric Infectious Diseases, Department of Pediatrics, University of Alabama at Birmingham, Birmingham, AL, USA.
| | - Michael O Alberti
- Division of Pediatric Infectious Diseases, Department of Pediatrics, University of Alabama at Birmingham, Birmingham, AL, USA.
| | - Mourad Ismail
- Division of Hematology and Oncology, Department of Medicine, Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH, USA.
| | - Karen T Lingas
- Division of Hematology and Oncology, Department of Medicine, Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH, USA.
| | - Jane S Reese
- Division of Hematology and Oncology, Department of Medicine, Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH, USA; Seidman Cancer Center, University Hospitals Case Medical Center, Cleveland, OH, USA.
| | - Stanton L Gerson
- Division of Hematology and Oncology, Department of Medicine, Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH, USA; Seidman Cancer Center, University Hospitals Case Medical Center, Cleveland, OH, USA; National Center for Regenerative Medicine, Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH, USA; The Center for Stem Cell and Regenerative Medicine, Cleveland, OH, USA.
| |
Collapse
|
11
|
Roth JC, Ismail M, Reese JS, Lingas KT, Ferrari G, Gerson SL. Cotransduction with MGMT and Ubiquitous or Erythroid-Specific GFP Lentiviruses Allows Enrichment of Dual-Positive Hematopoietic Progenitor Cells In Vivo. ISRN Hematol 2012; 2012:212586. [PMID: 22888445 PMCID: PMC3408655 DOI: 10.5402/2012/212586] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/24/2012] [Accepted: 05/29/2012] [Indexed: 11/23/2022]
Abstract
The P140K point mutant of MGMT allows robust hematopoietic stem cell (HSC) enrichment in vivo. Thus, dual-gene vectors that couple MGMT and therapeutic gene expression have allowed enrichment of gene-corrected HSCs in animal models. However, expression levels from dual-gene vectors are often reduced for one or both genes. Further, it may be desirable to express selection and therapeutic genes at distinct stages of cell differentiation. In this regard, we evaluated whether hematopoietic cells could be efficiently cotransduced using low MOIs of two separate single-gene lentiviruses, including MGMT for dual-positive cell enrichment. Cotransduction efficiencies were evaluated using a range of MGMT : GFP virus ratios, MOIs, and selection stringencies in vitro. Cotransduction was optimal when equal proportions of each virus were used, but low MGMT : GFP virus ratios resulted in the highest proportion of dual-positive cells after selection. This strategy was then evaluated in murine models for in vivo selection of HSCs cotransduced with a ubiquitous MGMT expression vector and an erythroid-specific GFP vector. Although the MGMT and GFP expression percentages were variable among engrafted recipients, drug selection enriched MGMT-positive leukocyte and GFP-positive erythroid cell populations. These data demonstrate cotransduction as a mean to rapidly enrich and evaluate therapeutic lentivectors in vivo.
Collapse
Affiliation(s)
- Justin C Roth
- Division of Infectious Diseases, Department of Pediatrics, The University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | | | | | | | | | | |
Collapse
|
12
|
Reese JS, Roth JC, Gerson SL. Bone marrow-derived cells exhibiting lung epithelial cell characteristics are enriched in vivo using methylguanine DNA methyltransferase-mediated drug resistance. Stem Cells 2008; 26:675-81. [PMID: 18192231 DOI: 10.1634/stemcells.2007-0803] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Previous studies have suggested that donor bone marrow-derived cells can differentiate into lung epithelial cells at low frequency. We investigated whether we could enrich the number of donor-derived hematopoietic cells that have type II pneumocyte characteristics by overexpression of the drug resistance gene methylguanine DNA methyltransferase (MGMT). MGMT encodes O(6)-alkylguanine DNA alkyltransferase (AGT), a drug resistance protein for DNA damage induced by N,N'-bis(2-chloroethyl)-N-nitrosourea (BCNU), and the mutant P140K MGMT confers resistance to BCNU and the AGT inactivator O(6)-benzylguanine (BG). For this study, we used two MGMT selection models: one in which donor cells had a strong selection advantage because the recipient lung lacked MGMT expression, and another in which drug resistance was conferred by gene transfer of P140K MGMT. In both models, we saw an increase in the total number of donor-derived cells in the lung after BCNU treatment. Analysis of single-cell suspensions from 28 mice showed donor-derived cells with characteristics of type II pneumocytes, determined by surfactant protein C (SP-C) expression. Furthermore, an increase in the percentage of donor-derived SP-C cells was noted after BCNU or BG and BCNU treatment. This study demonstrates that bone marrow cells expressing MGMT can engraft in the lung and convert into cells expressing the type II pneumocyte protein SP-C. Furthermore, these cells can be enriched in response to alkylating agent-mediated lung injury. These results suggest that expression of MGMT could enhance the capacity of bone marrow-derived cells to repopulate lung epithelium, and when used in combination with a gene of interest, MGMT could have therapeutic applications.
Collapse
Affiliation(s)
- Jane S Reese
- Case Comprehensive Cancer Center, Case Western Reserve University, 11100 Euclid Avenue, Cleveland, Ohio 44106, USA
| | | | | |
Collapse
|
13
|
Zielske SP, Reese JS, Lingas KT, Donze JR, Gerson SL. In vivo selection of MGMT(P140K) lentivirus-transduced human NOD/SCID repopulating cells without pretransplant irradiation conditioning. J Clin Invest 2004; 112:1561-70. [PMID: 14617757 PMCID: PMC259124 DOI: 10.1172/jci17922] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Infusion of transduced hematopoietic stem cells into nonmyeloablated hosts results in ineffective in vivo levels of transduced cells. To increase the proportion of transduced cells in vivo, selection based on P140K O6-methylguanine-DNA-methyltransferase (MGMT[P140K]) gene transduction and O6-benzylguanine/1,3-bis(2-chloroethyl)-1-nitrosourea (BG/BCNU) treatment has been devised. In this study, we transduced human NOD/SCID repopulating cells (SRCs) with MGMT(P140K) using a lentiviral vector and infused them into BG/BCNU-conditioned NOD/SCID mice before rounds of BG/BCNU treatment as a model for in vivo selection. Engraftment was not observed until the second round of BG/BCNU treatment, at which time human cells emerged to compose up to 20% of the bone marrow. Furthermore, 99% of human CFCs derived from NOD/SCID mice were positive for provirus as measured by PCR, compared with 35% before transplant and 11% in untreated irradiation-preconditioned mice, demonstrating selection. Bone marrow showed BG-resistant O6-alkylguanine-DNA-alkyltransferase (AGT) activity, and CFUs were stained intensely for AGT protein, indicating high transgene expression. Real-time PCR estimates of the number of proviral insertions in individual CFUs ranged from 3 to 22. Selection resulted in expansion of one or more SRC clones containing similar numbers of proviral copies per mouse. To our knowledge, these results provide the first evidence of potent in vivo selection of MGMT(P140K) lentivirus-transduced human SRCs following BG/BCNU treatment.
Collapse
Affiliation(s)
- Steven P Zielske
- Molecular Virology Program, Case Western Reserve University, Cleveland, Ohio 44106, USA
| | | | | | | | | |
Collapse
|
14
|
Zielske SP, Reese JS, Lingas KT, Donze JR, Gerson SL. In vivo selection of MGMT(P140K) lentivirus–transduced human NOD/SCID repopulating cells without pretransplant irradiation conditioning. J Clin Invest 2003. [DOI: 10.1172/jci200317922] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
|
15
|
Abstract
Mismatch repair deficiency is associated with carcinogenesis, increased spontaneous and induced mutagenesis, and resistance to methylating agents. In humans, leukemias and lymphomas arise in the background of mismatch repair deficiency, raising the possibility that hematopoiesis is abnormal as well. To address hematopoiesis in MSH2-/- mice, we collected marrow and performed serial transplantations of these cells, alone or mixed with wild-type cells, into lethally irradiated healthy mice. Transplant recipients were observed or treated with the methylating agent, temozolomide (TMZ). Methylating agent tolerance was evident by the competitive survival advantage of MSH2-/- marrow progenitors compared with wild-type cells after each TMZ exposure. However, serial repopulation by MSH2-/- cells was deficient compared with wild-type cells. In recipients of mixed populations, the MSH 2-/- cells were lost from the marrow, and mice receiving MSH2-/- cells plus TMZ could not be reconstituted in the third passage, whereas all wild-type cell recipients survived. No differences in telomere length, cell cycle distribution, or homing were observed, but an increase in microsatellite instability was seen in the MSH2-/- early progenitor colony-forming unit (CFU) and Sca+Kit+lin--derived clones. Thus, mismatch repair deficiency is associated with a hematopoietic repopulation defect and stem cell exhaustion because of accumulation of genomic instability.
Collapse
Affiliation(s)
- Jane S Reese
- BRB 3, 10900 Euclid Ave, Cleveland, OH 44106, USA
| | | | | |
Collapse
|
16
|
Davis BM, Reese JS, Lingas K, Gerson SL. Drug selection of mutant methylguanine methyltransferase from different oncoretroviral backbones results in multilineage hematopoietic transgene expression in primary and secondary recipients. J Hematother Stem Cell Res 2003; 12:375-87. [PMID: 12965075 DOI: 10.1089/152581603322286015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Optimized hematopoietic gene therapy requires vectors with strong expression in the desired target cell population and the ability to select for the expressing transduced cells. In the context of drug resistance selection of repopulating hematopoietic stem cells in the mouse, we examined tissue expression after transduced marrow transplantation of the drug selection gene, G156A mutant O6-methylguanine-DNA methyltransferase (G156A MGMT). To gain more experience with the rigor of the impact of selection on tissue-specific gene expression, we also asked whether there are expression differences between three different onco-retroviral backbones--MPSV, SF, and MFG. MGMT expression was compared after O6-benzylguanine (BG) and 1,3-bis (2-chloroethyl)-1-nitrosourea (BCNU) drug selection in vivo. After mice were transplanted with cells transduced with MPSV, MFG, or SF retroviral vectors expressing G156A MGMT and drug treated, nearly complete replacement by transduced progenitors was observed in the marrow. Each backbone supported MGMT expression in all four hematopoietic lineages in vivo indicating that MGMT-mediated selection is indeed robust. Expression in marrow, spleen, and thymus was very similar between the vectors and differences were most likely due to differences in gene copy number per selected cell. In primary and secondary recipients, the highest expression was observed in MFG and this was the vector that transduced at the greatest proviral copy number per cell. These data indicate that strong selection pressure using the MGMT gene to protect primary and secondary repopulating murine stem cells from the toxicity of BCNU. Regardless of the vector backbone used, multiorgan expression was observed without evidence of gene silencing. These data help establish mutant, BG-resistant MGMT as a potent selection gene for stem cell selection in vivo.
Collapse
Affiliation(s)
- Brian M Davis
- Division of Hematology/Oncology and the Comprehensive Cancer Center at Case Western Reserve University and University Hospitals of Cleveland, Cleveland, OH 44106-4937, USA
| | | | | | | |
Collapse
|
17
|
Abstract
The concept of hematopoietic stem cell gene therapy is as exciting as that of stem cell transplantation itself. The past 20 years of research have led to improved techniques for transferring and expressing genes in hematopoietic stem cells and preclinical models now routinely indicate the ease with which new genes can be expressed in repopulating stem cells of multiple species. Both modified murine oncoretroviruses and lentiviruses transmit genes into the genome of hematopoietic stem cells and allow expression in the host following transplantation. Using oncoretroviruses, therapeutic genes for severe combined immunodeficiency, common variable gamma chain immunodeficiency, chronic granulomatous disease, Hurler's and Gaucher's Disease have all been used clinically with only modest success except for the patients with immunodeficiency in whom a partial T-cell chimerism has been dramatic. Since stem cell selection in vivo appears important to the therapeutic success of gene transfer, drug resistance selection, most recently using the MGMT gene, has been developed and appears to be safe. Future trials combining a drug resistance and therapeutic gene are planned, as are trials using safety-modified lentiviruses. The therapeutic potential of hematopoietic stem cell gene therapy, particularly given recent advances in stem cell plasticity, remains an exceptionally exciting area of clinical research.
Collapse
Affiliation(s)
- J L Vollweiler
- Division of Hematology-Oncology, Comprehensive Cancer Center at University Hospitals of Cleveland, Case Western Reserve University School of Medicine, USA
| | | | | | | |
Collapse
|
18
|
Bowman JE, Reese JS, Lingas KT, Gerson SL. Myeloablation is not required to select and maintain expression of the drug-resistance gene, mutant MGMT, in primary and secondary recipients. Mol Ther 2003; 8:42-50. [PMID: 12842427 DOI: 10.1016/s1525-0016(03)00141-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Gene transduction of hematopoietic progenitors capable of reconstituting both primary and secondary recipients is an important milestone in preclinical development of gene therapy. Myeloablation conditioning prior to infusion of transduced stem cells causes significant host morbidity. In contrast, drug-resistance gene transfer utilizes judicious in vivo selection of transduced stem cells over time, reaching only the level of transduction and expression required. The O(6)-benzylguanine (BG)-resistant mutant O(6)-methylguanine-DNA methyltransferase (MGMT) gene is a potent selection gene for transduced cells. Using two different mutant MGMTs, G156A and P140K, that vary in BG resistance by a factor of 1:20, we asked whether long-term repopulating and secondary mouse-repopulating cells could be transduced, transplanted, and selected for in the nonmyeloablated recipient and whether the mutant MGMT would continue to be expressed in secondary recipient repopulating cells. We found that under stringent drug-selection competition, cells expressing the more BG-resistant variant, P140K-MGMT, were enriched over G156A-MGMT-expressing progenitors. In addition, the MFG retroviral vector transmitted the mutant MGMT gene to long-term repopulating cells that, after selective enrichment in the nonmyeloablated primary recipient, repopulated secondary mice and continued to express the transgene. Thus, MFG mutant MGMT vectors transduce repopulating hematopoietic stem cells that may be used both for chemotherapeutic drug resistance and to enrich for second therapeutic genes.
Collapse
Affiliation(s)
- Janice E Bowman
- Division of Hematology-Oncology and the Comprehensive Cancer Center, University Hospitals of Cleveland and Case Western Reserve University School of Medicine, 10900 Euclid Avenue, BRB 3-West, Cleveland, Ohio 44106-4937, USA
| | | | | | | |
Collapse
|
19
|
Reese JS, Allay E, Gerson SL. Overexpression of human O6-alkylguanine DNA alkyltransferase (AGT) prevents MNU induced lymphomas in heterozygous p53 deficient mice. Oncogene 2001; 20:5258-63. [PMID: 11536039 DOI: 10.1038/sj.onc.1204700] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2001] [Revised: 06/01/2001] [Accepted: 06/06/2001] [Indexed: 01/12/2023]
Abstract
O6-alkylguanine DNA alkyltransferase (AGT) is a key mechanism in the prevention against MNU induced malignant transformation by removal of O6 methyl guanine (O6mG) adducts. We asked whether heterozygous p53 deficient mice (p53+/-) would be more susceptible to MNU induced lymphomas than wild type mice, and whether O6mG adducts were responsible for this susceptibility. To determine whether MGMT overexpression would be protective, p53+/- mice were bred to human MGMT transgenic mice (MGMT+) and treated with 50 mg/kg MNU. MNU increased the incidence of thymic lymphomas in non-transgenic p53+/- mice from 23% (n=13) to 68% (n=22) and decreased the mean latency from 433 to 106 days (P=0.01 compared to untreated mice). Wild type mice had an incidence of 30% (n=38) and a mean latency of 135 days after MNU. Overexpression of MGMT in the thymus of p53+/- mice significantly reduced the lymphoma incidence from 68 to 28% (n=17) and increased the latency from 106 to 167 days (P=0.003). Similarly, the lymphoma incidence in MGMT+/wild type mice decreased from 30 to 8% (n=12) and the latency increased to 297 days (P=0.2). Loss of the wild type allele was found in only 2/17 lymphomas occurring in p53+/- mice and there were no significant point mutations in exons 5-8 of p53. Furthermore, there was no loss of p53 function in these mice. These data demonstrate that unrepaired O6mG lesions act cooperatively with the reduced p53 dose and lead to lymphomagenesis in p53+/- mice, but AGT overexpression and rapid removal of O6mG adducts is protective.
Collapse
Affiliation(s)
- J S Reese
- Division of Hematology/Oncology, University Hospitals of Cleveland, Cleveland, Ohio, OH 44106, USA
| | | | | |
Collapse
|
20
|
Reese JS, Qin X, Ballas CB, Sekiguchi M, Gerson SL. MGMT expression in murine bone marrow is a major determinant of animal survival after alkylating agent exposure. J Hematother Stem Cell Res 2001; 10:115-23. [PMID: 11276365 DOI: 10.1089/152581601750098354] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Myelosuppression is commonly observed after alkylating agent chemotherapy due to low levels of O(6)-alkylguanine DNA alkyltransferase protein (AGT) in hematopoietic progenitors. Mice that lack AGT in all organs, O(6)-methylguanine-DNA methyltransferase gene knockout (MGMT(-/-)) mice are extremely hypersensitive to the methylating agent N-methyl-N-nitrosourea (MNU) and exhibit a 10-fold reduction in the LD(90). To determine whether bone marrow damage was the cause of the increased lethality, we transplanted 1 x 10(6) wild-type marrow into MGMT(-/-) mice and MGMT(-/-) marrow into wild-type mice and observed survival after MNU. Lethally irradiated MGMT(-/-) mice given > or = 25 mg/kg MNU 3 weeks after transplant of wild-type cells survived > 30 days (n = 11), whereas this dose was lethal to control MGMT(-/-) mice 9-12 days post treatment (n = 5). Conversely, lethally irradiated wild-type mice transplanted with MGMT(-/-) cells died after only 20-60 mg/kg MNU within 8-12 days (n = 6). No significant toxicities were found in other organs. Additionally, in an in vivo post transplant competition model, wild-type long-term repopulating cells had a > 200-fold competitive survival advantage over MGMT(-/-) cells, and after MNU treatment completely repopulated the mouse when transplanted at only one-tenth the cell number. We also observed a strong selection for transplanted marrow-derived wild-type stromal elements in the MGMT(-/-) background after drug treatment. These data indicate that alkylating agent hypersensitivity of MGMT(-/-) mice results from hematopoietic damage at the stem level. Thus, DNA repair involving AGT in hematopoietic cells is required for normal host survival following exposure to methylating and chloroethylating agents.
Collapse
Affiliation(s)
- J S Reese
- Division of Hematology/Oncology, Case Western Reserve University and University Hospitals, Ireland Cancer Center, Cleveland, OH 44106, USA
| | | | | | | | | |
Collapse
|
21
|
Abstract
Human mesenchymal stem cells (hMSC)-nonhematopoietic cells within the bone marrow microenvironment that can be culture expanded to a uniform population of fibroblastic cells-have been shown to support long-term hematopoiesis of CD34+ cells. Because direct contact between stromal elements and CD34+ cells enhances long-term engraftment, we postulated that hMSC would be a good alternative to the more heterogeneous stroma currently used in gene transfer studies. We used hMSC to support retroviral gene transfer of the G156A MGMT (deltaMGMT) gene encoding an alkyltransferase (AGT), which confers drug resistance to a combination of O6-benzylguanine (BG) plus the alkylating agents BCNU and temozolomide (TMZ) in human hematopoietic progenitors. In the presence of IL-3, IL-6, SCF, or leukemia inhibitory factor (LIF) and Flt-3 ligand, hMSC facilitated expansion and retroviral transduction of human peripheral blood-mobilized CD34+ cells. Furthermore, the transduced cells expressed AGT in 29% of hematopoietic cells and were 5-fold more resistant to BCNU and TMZ than were untransduced cells. Unirradiated hMSC present as support cells were simultaneously transduced and expressed AGT in 26% of the cells. Thus, the homogeneous nature of hMSC, and their ability to support gene transfer and be transduced themselves suggest they may be useful in clinical gene transfer protocols and have broad therapeutic applications.
Collapse
Affiliation(s)
- J S Reese
- Division of Hematology/Oncology, Case Western Reserve University and University Hospitals, Ireland Cancer Center, Cleveland, OH 44106, USA
| | | | | |
Collapse
|
22
|
Davis BM, Koç ON, Reese JS, Gerson SL. O6-benzylguanine-resistant mutant MGMT genes improve hematopoietic cell tolerance to alkylating agents. Prog Exp Tumor Res 1999; 36:65-81. [PMID: 10386065 DOI: 10.1159/000061986] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- B M Davis
- Division of Hematology/Oncology, Case Western Reserve University, Cleveland, Ohio, USA
| | | | | | | |
Collapse
|
23
|
Koç ON, Reese JS, Szekely EM, Gerson SL. Human long-term culture initiating cells are sensitive to benzylguanine and 1,3-bis(2-chloroethyl)-1-nitrosourea and protected after mutant (G156A) methylguanine methyltransferase gene transfer. Cancer Gene Ther 1999; 6:340-8. [PMID: 10419052 DOI: 10.1038/sj.cgt.7700067] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Human hematopoietic progenitors express low levels of O6-alkylguanine-DNA alkyltransferase and are sensitive to 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU), particularly following O6-benzylguanine (BG)-mediated O6-alkylguanine-DNA alkyltransferase inhibition. Expression of the BG-resistant mutant (G156A) methylguanine methyltransferase (deltaMGMT) gene in hematopoietic cells confers resistance to BG and BCNU. Because BCNU targets both early and late human hematopoietic cells and results in prolonged and cumulative myelosuppression, we attempted to protect early hematopoietic progenitors (long-term culture initiating cells (LTC-ICs)) by retroviral-mediated transfer of the deltaMGMTgene. A total of 33-56% of LTC-ICs were transduced with MFG-deltaMGMT retrovirus as determined by evidence of provirus in secondary colony-forming units at 5 weeks of culture under conditions optimal for the survival and proliferation of early hematopoietic progenitors. The addition of flt-3 ligand to cultures increased the transduction rate of LTC-ICs. Furthermore, 17.8 +/- 8.1% of deltaMGMT-transduced LTC-ICs survived doses of BG and BCNU; these doses allowed the survival of only 0-1% of untransduced LTC-ICs. This finding compares favorably with the 8-12% of CD34+ cell-derived colony-forming units that we previously showed became resistant to BG and BCNU after deltaMGMTgene transfer. Thus, deltaMGMT transduction of human early hematopoietic progenitor LTC-ICs confers resistance to BG and BCNU and may allow transduced LTC-ICs selective survival and enrichment over untransduced cells in patients undergoing BG and BCNU chemotherapy.
Collapse
Affiliation(s)
- O N Koç
- Division of Hematology/Oncology, Case Western Reserve University/University Hospitals Ireland Cancer Center, Cleveland, Ohio 44106, USA.
| | | | | | | |
Collapse
|
24
|
Koç ON, Reese JS, Davis BM, Liu L, Majczenko KJ, Gerson SL. DeltaMGMT-transduced bone marrow infusion increases tolerance to O6-benzylguanine and 1,3-bis(2-chloroethyl)-1-nitrosourea and allows intensive therapy of 1,3-bis(2-chloroethyl)-1-nitrosourea-resistant human colon cancer xenografts. Hum Gene Ther 1999; 10:1021-30. [PMID: 10223735 DOI: 10.1089/10430349950018418] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
O6-Benzylguanine (BG) is a potent inhibitor of the DNA repair protein 06-alkylguanine DNA alkyltransferase (AGT), and sensitizes tumors to BCNU in vitro and in xenografts. The combination of BG and BCNU is now undergoing phase I clinical testing. The maximally tolerated dose of BCNU given after BG is expected to be lower then the doses tolerated as a single agent owing to BG sensitization of hematopoietic progenitors. We have previously shown that retroviral expression of G156A mutant MGMT (deltaMGMT) in mouse and human marrow cells results in significant BG and BCNU resistance. In this study we evaluated the effect of deltaMGMT-transduced marrow infusion on the therapeutic index of multiple BG and BCNU treatments in tumor-bearing nude (nu/nu athymic) mice. Prior to subcutaneous implantation of BCNU-resistant SW480 human colon cancer cells, cohorts of mice were given intraperitoneal injections of nonablative doses of BG (30 mg/kg) and BCNU (10 mg/kg, one-half of the LD10) and then infused with 1-2 x 10(6) isogeneic deltaMGMT (n = 29 mice) or lacZ-transduced (n = 20 mice) marrow cells. The xenograft-bearing mice were treated with multiple cycles of BG (30 mg/kg) and BCNU (10-25 mg/kg). After three cycles, deltaMGMT mouse bone marrow was repopulated with CFU containing the provirus, and demonstrated a 2.7-fold increase in AGT activity and a 5.5-fold increase in BCNU IC90 compared with LacZ mice. After five cycles, the BCNU IC90 of CFU cells increased nine-fold over control cells, indicating selective enrichment of CFU precursor cells expressing high levels of deltaMGMT. Starting with the third cycle of therapy, tolerance to BG and BCNU was significantly improved in deltaMGMT mice compared with LacZ mice, as evidenced by preserved peripheral blood counts, bone marrow cellularity, and CFU content 1 and 2 weeks posttreatment and a significantly higher survival rate. Xenograft growth was significantly delayed in mice tolerating multiple cycles and higher dose intensity of BG and BCNU as compared with mice receiving less intensive therapy. We conclude that deltaMGMT-transduced marrow cells can improve the therapeutic index of BG and BCNU by selectively repopulating the marrow and providing significant marrow tolerance to this combination, allowing intensive therapy of a BCNU-resistant tumor.
Collapse
Affiliation(s)
- O N Koç
- Division of Hematology/Oncology and the Ireland Cancer Center of University Hospitals of Cleveland and Case Western Reserve University, OH 44106, USA.
| | | | | | | | | | | |
Collapse
|
25
|
Reese JS, Davis BM, Liu L, Gerson SL. Simultaneous protection of G156A methylguanine DNA methyltransferase gene-transduced hematopoietic progenitors and sensitization of tumor cells using O6-benzylguanine and temozolomide. Clin Cancer Res 1999; 5:163-9. [PMID: 9918215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
O6-Benzylguanine (BG) potentiates temozolomide (TMZ) cytotoxicity in tumors by inactivating O6-alkylguanine DNA alkyltransferase but also increases toxicity in hematopoietic cells. To improve the hematopoietic cell tolerance to alkylating agents, we retrovirally transduced the BG-resistant mutant G156A methylguanine DNA methyltransferase gene (deltaMGMT) into hematopoietic progenitors and evaluated whether deltaMGMT expression in hematopoietic colony-forming units would result in greater drug resistance to TMZ. DeltaMGMT expression in human and mouse colony-forming units followed by BG treatment resulted in a >7.7-fold increase in the TMZ 90% inhibitory concentration (IC90) and a 5.6-fold increase in the 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) IC90 relative to untransduced cells. This degree of protection enabled deltaMGMT-transduced CD34 cells to become much more resistant to BG and TMZ than SW480 cells, which express high O6-alkylguanine DNA alkyltransferase and are normally resistant to TMZ or BCNU alone. DeltaMGMT-transduced long-term culture initiating cells were also resistant to the BG and TMZ combination, as were untransduced long-term culture initiating cells, suggesting that noncycling early progenitors may be partially protected from TMZ. These data indicate that retroviral transduction of deltaMGMT into hematopoietic progenitors followed by BG and TMZ treatment may selectively protect hematopoietic cells more efficiently than BCNU, allowing dose-intensive and repetitive therapy without the risk of cumulative myelosuppression.
Collapse
Affiliation(s)
- J S Reese
- Division of Hematology/Oncology, Case Western Reserve University and University Hospitals Ireland Cancer Center, Cleveland, Ohio 44106-4937, USA
| | | | | | | |
Collapse
|
26
|
Davis BM, Reese JS, Koç ON, Lee K, Schupp JE, Gerson SL. Selection for G156A O6-methylguanine DNA methyltransferase gene-transduced hematopoietic progenitors and protection from lethality in mice treated with O6-benzylguanine and 1,3-bis(2-chloroethyl)-1-nitrosourea. Cancer Res 1997; 57:5093-9. [PMID: 9371508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A retroviral gene therapy approach was developed to protect early hematopoietic progenitors from 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU), a stem cell toxin, and O6-benzylguanine (BG), an inhibitor of a key BCNU resistance protein, O6-alkylguanine DNA alkyltransferase (AGT). The retroviral vector MFG was used to transfer the G156A MGMT (deltaMGMT) cDNA, encoding a mutant AGT that is resistant to inhibition by BG, into murine bone marrow-derived hematopoietic progenitors. Following transplantation into lethally irradiated mice, the transduced cells were subjected to in vivo BG and BCNU treatment to examine the ability to enrich for transduced cells expressing deltaAGT. Transplantation of deltaMGMT-transduced cells resulted in deltaAGT expression in 30% of bone marrow nucleated cells 13 weeks after transplantation. After one cycle of BG and BCNU, deltaAGT expression was observed in 60% of bone marrow cells, and the percentage of colony-forming units (culture; CFU-C) containing proviral sequence increased from 67 to 100%. CFU-C obtained from BG and BCNU-treated deltaMGMT animals up to 23 weeks after transplantation were more resistant to combination BG and BCNU than CFU-C from mice transplanted with lacZ-transduced cells and treated with BG and BCNU or from mice transplanted with deltaMGMT-transduced cells and left untreated. The degree of drug resistance in deltaMGMT-transduced hematopoietic progenitors to BG and BCNU was much greater than we observed previously with wild-type MGMT gene transfer and treatment with BCNU alone. Furthermore, whereas 21 of 22 mice transplanted with deltaMGMT-transduced cells survived in vivo BG and BCNU administration, only 3 of 13 mice transplanted with lacZ-transduced progenitors survived similar drug treatment. Thus, deltaMGMT-transduced murine bone marrow cells selectively survive in vivo BG and BCNU exposure, resulting in prolonged enrichment for the transduced cells and protection from mortality induced by this drug combination.
Collapse
Affiliation(s)
- B M Davis
- Division of Hematology/Oncology and Molecular Virology Training Program, Case Western Reserve University, University Hospitals of Cleveland Ireland Cancer Center, Ohio 44106, USA
| | | | | | | | | | | |
Collapse
|
27
|
Hoover F, Hankin MH, Radel JD, Reese JS, Goldman D. Axon-target interactions maintain synaptic gene expression in retinae transplanted to intracranial regions of the rat. Brain Res Mol Brain Res 1997; 51:123-32. [PMID: 9427514 DOI: 10.1016/s0169-328x(97)00228-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In the present study we examined the effects of optic axon-CNS target interactions on gene expression in the rat retina. These studies took advantage of a transplantation paradigm that allowed us to assay gene expression in retinae transplanted to different intracranial locations in the neonatal rat that either promoted (dorsal midbrain) or precluded (cerebral cortex) the formation of retino-collicular connections. Using in situ hybridization experiments, we observed that transplantation to the dorsal midbrain resulted in a relatively normal pattern of nicotinic acetylcholine receptor (nAChR) beta-3 subunit and glutamate receptor 3 (GluR3) gene expression. In contrast, retinae transplanted to the cerebral cortex (which did not result in normal retino-collicular interactions) showed a dramatic reduction in nAChR beta-3 subunit and GluR3 gene expression. These results agree with those obtained in the adult goldfish retina, where it has been demonstrated that an optic nerve-optic tectum interaction is responsible for the re-induction nAChR and NMDA receptor gene expression during optic nerve regeneration. Taken together, these results support the hypothesis that proper axon-target interactions are required for maintenance of nAChR and glutamate receptor gene expression in the mature vertebrate retina.
Collapse
Affiliation(s)
- F Hoover
- Mental Health Research Institute and Department of Biological Chemistry, University of Michigan, Ann Arbor 48109, USA.
| | | | | | | | | |
Collapse
|
28
|
Allay E, Reese JS, McGuire EA, Koç ON, Sedransk N, Gerson SL. Potentiation of lymphomagenesis by methylnitrosourea in mice transgenic for LMO1 is blocked by O6-alkylguanine DNA-alkyltransferase. Oncogene 1997; 15:2127-32. [PMID: 9366529 DOI: 10.1038/sj.onc.1201384] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We evaluated induction of lymphomas by the methylating carcinogen, N-methylnitrosourea [MNU], in transgenic mice expressing both LMO1 and the DNA repair gene, MGMT, in the thymus. The goal was to determine whether environmental mutagens shorten the latency or increase the incidence of LMO1 + lymphomas and whether mice transgenic for both LMO1 and MGMT, and thereby able to repair O6-methylguanine DNA adducts induced by MNU, would be protected. Mice heterozygous for LMO1 or MGMT were crossed and offspring treated with MNU at 6 weeks of age. MNU induced lymphoma incidence was highest in the LMO1 mice, 91% and lowest in the hMGMT + mice, 15%. MNU induced K-ras mutations in codon 12 in non-MGMT transgenics resulted in a shorter latency of tumors and accounting for half of the early lymphomas in LMO1 mice. The effect of MNU was abrogated in the LMO1/hMGMT transgenic mice, indicating the ability of MGMT expression to block the carcinogenic effect of MNU even in cancer prone mice. Thus, methylating agents potentiate lymphomagenesis of LMO1, in part through activation of K-ras and the MAPK pathway, a process which appear to synergize with LMO1 mediated transcription activation. O6-alkylguanine DNA-alkyltransferase mediated DNA repair effectively blocks chemical carcinogenesis in mice carrying the LMO1 oncogene.
Collapse
Affiliation(s)
- E Allay
- Division of Hematology-Oncology and the CWRU/Ireland Cancer Center, Case Western Reserve University School of Medicine and University Hospitals of Cleveland, OH, USA
| | | | | | | | | | | |
Collapse
|
29
|
Reese JS, Koç ON, Lee KM, Liu L, Allay JA, Phillips WP, Gerson SL. Retroviral transduction of a mutant methylguanine DNA methyltransferase gene into human CD34 cells confers resistance to O6-benzylguanine plus 1,3-bis(2-chloroethyl)-1-nitrosourea. Proc Natl Acad Sci U S A 1996; 93:14088-93. [PMID: 8943065 PMCID: PMC19499 DOI: 10.1073/pnas.93.24.14088] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/1996] [Accepted: 09/12/1996] [Indexed: 02/03/2023] Open
Abstract
Human CD34 cells express low levels of the DNA repair protein O6-alkylguanine-DNA alkyltransferase (AGT) and are sensitive to 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU). Gene transfer of the AGT gene, methylguanine DNA methyltransferase (MGMT), results in only modest BCNU resistance. Recently, an AGT inhibitor, O6-benzylguanine (BG), entered clinical trials. In preclinical studies, BG potentiated the cytotoxic effect of BCNU in tumors but increased toxicity to normal CD34 cells. We transferred a mutant MGMT containing a glycine-to-alanine mutation at position 156, resulting in marked resistance to BG, into Chinese hamster cells; the K562 cell line and human CD34 cells used the retroviral backbone MFG. In each instance, cells expressed increased AGT and were much more resistant to the combination of BG and BCNU than the parental cells or cells transduced with wild-type MGMT. Furthermore, the transduction efficiency in human CD34 cells was in excess of 70%, and the proportion of CD34 transduced cells resistant to the combination was > 30%. Thus, retroviral-mediated transduction of a mutant MGMT into CD34 cells appears to be an effective way to induce selective resistance to a drug combination designed to overcome a significant resistance mechanism to nitrosoureas in tumors.
Collapse
Affiliation(s)
- J S Reese
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | | | | | | | | | | | | |
Collapse
|
30
|
Abstract
In the present study we investigated the expression and regulation of the opsin gene in retinal transplants. Embryonic retinae were transplanted to intracranial locations in neonatal rodents in which they either reliably projected to the superior colliculus, or in locations (such as the cerebral cortex) in which they did not project to subcortical visual nuclei. Our results show that, regardless of the graft location, the developmental schedule of opsin gene expression in the outer nuclear layer was similar to normal, and that it was maintained in transplants for at least 6 months. To test if ambient light affected opsin gene expression, we dark-reared rats containing a retinal transplant for up to 26 days before assaying for opsin transcripts. In situ hybridization experiments showed that opsin gene expression in the transplants of these dark-reared recipients was not different either from transplants in animals reared in cyclic light conditions, or from the retina in situ. These observations support the hypothesis that the opsin gene is activated and maintained by molecular mechanisms intrinsic to the photoreceptor.
Collapse
Affiliation(s)
- F Hoover
- Mental Health Research Institute, University of Michigan, Ann Arbor 48109, USA.
| | | | | | | | | |
Collapse
|
31
|
Koç ON, Allay JA, Lee K, Davis BM, Reese JS, Gerson SL. Transfer of drug resistance genes into hematopoietic progenitors to improve chemotherapy tolerance. Semin Oncol 1996; 23:46-65. [PMID: 8607032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
A number of drug resistance genes have been identified that may be useful in gene therapy approaches to ameliorate chemotherapy toxicity. Hematopoietic tissue is the most suitable target for drug resistance gene therapy because myelosuppression is the dose-limiting toxicity of the many chemotherapeutic agents. Recent studies have shown that murine and human hematopoietic progenitors can be transduced ex vivo using retroviral vectors to overexpress P-glycoprotein, dihydrofolate reductase, and O6-alkylguanine DNA alkyltransferase. In all instances, gene transfer results in significant drug resistance in hematopoietic progenitors both in vitro and in vivo. Clinical trials are underway to evaluate the role of MDR-1 gene therapy in amelioration of chemotherapy induced myelosuppression. Other genes being examined for their potential to transfer drug resistance to hematopoietic cells include genes encoding aldehyde dehydrogenase, nucleotide excision repair proteins, multidrug resistant protein, and superoxide dismutase. As a group these proteins could confer significant levels of chemotherapy drug resistance to bone marrow cells. When compared with other somatic gene therapy approaches, drug resistance gene therapy has the aim of protecting normal cells and preventing toxicity. In addition many of these genes could be used to select for cells carrying the drug resistance gene as well as cotransduced therapeutic gene. Thus, gene transfer of drug resistance genes will have broad applications in the field of gene therapy as well as in protecting hematopoietic cells from chemotherapy toxicity.
Collapse
Affiliation(s)
- O N Koç
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
| | | | | | | | | | | |
Collapse
|