Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0018133 (graft-versus-host disease)
 18,032 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Allogeneic bone marrow transplantation (BMT) is associated with a severe complication--graft-versus-host disease (GVHD). Although effectively preventing GVHD, ex vivo T-lymphocyte marrow depletion unfortunately increases graft rejection and reduces the graft-versus-leukemia (GVL) effect. The ex vivo transfer of the herpes simplex thymidine kinase (HS-tk) suicide gene into T cells before their infusion with hematopoietic stem cells could allow for selective in vivo depletion of these T cells with ganciclovir (GCV) if subsequent GVHD was to occur. Thus, one could preserve the beneficial effects of the T cells on engraftment and tumor control in patients not experiencing severe GVHD. To obtain T cells specifically depleted by GCV, we transduced primary T cells with a retroviral vector containing the HS-tk and neomycin resistance (NeoR) genes. Gene transfer was performed by coculturing PHA +/- CD3- or alloantigen-stimulated purified T cells on an irradiated retroviral vector producer cell line or by incubating the T cells in supernatant from the producer. Subsequent culture in G418 for 1 week allowed for the selection of transduced cells. GCV treatment of interleukin-2-responding transduced and selected cells resulted in greater than 80% growth inhibition, whereas GCV treatment of control cells had no effect. Similarly, the allogeneic reactivity of HS-tk-transduced cells was specifically inhibited by GCV. Combining transduced and nontransduced T cells did not show a bystander effect, thus implying that all of the cells inhibited by GCV were indeed transduced. Lastly, studies involving the transduction of the HUT-78 (T-lymphoma) cell line suggest that stable expression of HS-tk can be maintained over 3 months in vitro in the absence of G418. In summary, we have established the feasibility of generating HS-tk-transduced T cells for subsequent in vivo transfer with hematopoietic stem cells and, if GVHD occurs, specific in vivo GCV-induced T-cell depletion in allogeneic BMT recipients.
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PMID:Ganciclovir treatment of herpes simplex thymidine kinase-transduced primary T lymphocytes: an approach for specific in vivo donor T-cell depletion after bone marrow transplantation? 804 49

Allogeneic bone marrow transplantation is still limited by the morbidity and mortality caused by graft-versus-host disease (GVHD), resulting from host recognition by donor T lymphocytes. It is possible to drastically reduce the T-cell content of the graft. However, transplanted T cells can also have a beneficial effect by graft enhancement and the graft-versus-leukemia effect. How can we keep the beneficial GVL effect while protecting the patient from possible GVHD? A recent report proposed the ex vivo transfer of the herpes simplex thymidine kinase (HSv-tk) gene into donor T cells before their infusion with hematopoietic stem cells. This procedure is expected to allow selective donor T-cell depletion with ganciclovir should GVHD occur, but it has two major drawbacks: reinjection of a fraction of untransfected T cells cannot be avoided and heterogeneity of the transfected population results in increased risks such as HSv-tk gene instability or dysfunction of some of the transfected T cell. Alternative approaches must be considered. We demonstrate here the feasibility of generating HSv-tk transfected HLA-specific CD4+ cytotoxic T-cell clonal populations, in which 100% of the cells have the HSv-tk gene inserted at a single site within their genome. These clones retained their specificity, their function, and their sensitivity to ganciclovir treatment. Our approach is not limited to bone marrow transplantation. Indeed, this procedure represents a useful alternative to retroviral gene transduction and is applicable to every circumstance where clinical use of gene modified T-cell clones is to be considered.
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PMID:Human HLA-specific T-cell clones with stable expression of a suicide gene: a possible tool to drive and control a graft-versus-host- graft-versus-leukemia reaction? 870 20

Based on the concept of circulating hematopoietic stem cells with indefinite self-renewal capacity that gives rise to all three cell lineages, peripheral blood progenitor cells (PBPCs) have widely replaced the use of bone marrow (BM) progenitors for autologous transplantation purposes in patients with malignant hematological disorders and selected solid tumors. Ex vivo purification of normal CD34+ cell subsets contained in the patient's apheresis product possibly eliminates clonogenic tumor cells, but also serves as a target cell population for gene transduction. Genetic tagging of PBPC autografts has proven that: 1) NEOR gene expression is sustained for more than 18 months and 2) clonogenic tumor cells contaminating the autograft contribute to relapse. A second generation of gene transduction studies includes new treatment strategies such as the induction of chemoprotection (multidrug resistance gene-1), chemotherapy sensitization (p53), cancer vaccination and genetic chemosensitization. Most recently allogeneic PBPC transplantation has successfully been introduced with the intention of improving the graft-versus-leukemia effect without inducing a higher incidence or more severe graft-versus-host disease (GVHD) than what is expected after BM transplantation. Introducing the herpes virus thymidine kinase cDNA into activated donor T cells makes them susceptible to gangciclovir, thus allowing the in vivo inactivation of GVHD-inducing T cells. With the close interaction of molecular genetics and clinical oncology/hematology, genetic engineering of stem cell grafts will lead into a new stage of stem cell transplantation technology.
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PMID:Blood stem cell transplantation and gene therapy of cancer. 874 97

A number of diverse gene therapy strategies are being evaluated in the search for novel therapeutic approaches to leukemia. Antisense oligonucleotides, ribozymes and retroviral vectors are approaches directed at the molecular mechanisms of cancer. Transfer of genes encoding cytokines and human leukocyte antigens (HLAs) could also be used to elicit immunity against tumor cells. Gene marking strategies have been useful in elucidating the biology of disease relapse after autologous bone marrow transplantation. Suicide genes, such as the herpes simplex thymidine kinase gene, have been used to modulate graft-versus-host disease after allogeneic bone marrow transplantation. Although gene delivery remains a major challenge to gene therapy, some modifications have been implemented to overcome this issue. This review will summarize these gene therapy strategies aimed at increasing the survival of patients with leukemia.
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PMID:Gene therapy strategies for leukemia. 902 41

A graft-versus-leukemia (GVL) effect has been considered a major factor responsible for cures in patients with hematologic malignancies undergoing allogeneic bone marrow transplantation; however, associated graft-versus-host disease (GVHD) results in significant morbidity and mortality. T-cell depletion reduces the incidence and severity of GVHD but eliminates, at least partially, the GVL effect. Reinfusion of donor T lymphocytes at relapse posttransplantation can induce a potent antitumor response, but GVHD still occurs in the majority of patients. Prior transduction of T lymphocytes with the suicide gene, the viral thymidine kinase (TK), permits specific cell kill on administration of ganciclovir (GCV). Therefore, infusion of TK-transduced T lymphocytes may induce GVL effect and allow for their subsequent selective elimination in case GVHD develops. To evaluate the efficacy and feasibility of this promising approach, anti-CD3-stimulated primary human lymphocytes cultured in interleukin-2 were TK-transduced by a retroviral vector carrying both TK and neomycin-resistance genes. After selection in G418, more than 90% of the cells contained the TK gene as shown by a semiquantitative polymerase chain reaction. In addition, 1 to 5 days of GCV exposure, at clinically achievable concentrations of 20 to 50 micromol/L, induced > or = 90% killing of G418-selected cells without affecting nontransduced cells. Correlation of the extent of T-cell kill and the proportion of TK-gene-transduced cells is consistent with the absence of a bystander effect. Transduced cells were CD3+ and either CD8+ or CD4+ and retained functional properties of untransduced cells. In vivo administration of GCV prevented tumor development after subcutaneous injection of TK-transduced murine myeloma cells (MOPC-11), whereas such an effect was not observed on injection of untransduced cells into the opposite flank. Our studies provide critical information that (1) adequate numbers of TK-transduced lymphocytes can be selected efficiently with > or = 90% purity, (2) selected cells remain functional, (3) 24 hours of exposure to GCV at clinically achievable concentration effects > or = 90% killing of selected cells, and (4) GCV is effective in vivo in killing TK-transduced cells. Based on these data, a clinical study has been initiated in patients with multiple myeloma with persistent or relapsing disease after T-cell-depleted allogeneic transplants.
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PMID:Thymidine kinase (TK) gene-transduced human lymphocytes can be highly purified, remain fully functional, and are killed efficiently with ganciclovir. 902 56

In allogeneic bone marrow transplantation (allo-BMT), donor lymphocytes play a central therapeutic role in both graft-versus-leukemia (GvL) and immune reconstitution. However, their use is limited by the risk of severe graft-versus-host disease (GvHD). Eight patients who relapsed or developed Epstein-Barr virus-induced lymphoma after T cell-depleted BMT were then treated with donor lymphocytes transduced with the herpes simplex virus thymidine kinase (HSV-TK) suicide gene. The transduced lymphocytes survived for up to 12 months, resulting in antitumor activity in five patients. Three patients developed GvHD, which could be effectively controlled by ganciclovir-induced elimination of the transduced cells. These data show that genetic manipulation of donor lymphocytes may increase the efficacy and safety of allo-BMT and expand its application to a larger number of patients.
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PMID:HSV-TK gene transfer into donor lymphocytes for control of allogeneic graft-versus-leukemia. 920 27

Alloreactive T cells present in a bone marrow transplant are responsible for graft-versus-host disease (GVHD), but their depletion is associated with impaired engraftment, immunosuppression, and loss of the graft-versus-leukemia effect. We developed a therapeutic strategy against GVHD based on the selective destruction of these alloreactive T cells, while preserving a competent T-cell pool of donor origin. We generated transgenic mice expressing in their T lymphocytes the Herpes simplex type 1 thymidine kinase (TK) suicide gene that allows the destruction of dividing T cells by a ganciclovir treatment. T cells expressing the TK transgene were used to generate GVHD in irradiated bone marrow grafted mice. We show that a short 7-day ganciclovir treatment, initiated at the time of bone marrow transplantation, efficiently prevented GVHD in mice receiving TK-expressing T cells. These mice were healthy and had a normal survival. They maintained a T-cell pool of donor origin that responded normally to in vitro stimulation with mitogens or third party alloantigens, but were tolerant to recipient alloantigens. Our experimental system provides the proof of concept for a therapeutic strategy of GVHD prevention using genetically engineered T cells.
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PMID:Prevention of graft-versus-host disease in mice using a suicide gene expressed in T lymphocytes. 919 90

This study will evaluate the safety and efficacy of allogenic donor lymphocyte infusions in patients who have relapsed hematologic malignancies after allogeneic bone marrow transplantation (BMT). Donor lymphocyte transfusions have resulted in the cure of some patients with relapsed leukemia or lymphoproliferative disorder after allogeneic BMT, but has been complicated by the development of graft versus host disease (GvHD). We hypothesize that a retroviral vector containing the Herpes simplex thymidine kinase (HStk) gene will allow for retention of the anti-leukemia response of transfused donor lymphocytes while allowing for the adverse effects of GVHD to be mitigated. Patients with relapsed hematologic malignancies after allogeneic BMT will be infused with ex vivo gene modified donor lymphocytes. The Herpes Simplex thymidine kinase (HStk) gene will be transduced into the cells ex vivo using LTKOSN. 1 vector supernate. Insertion of the HStk gene into lymphocytes confers a sensitivity to the anti-herpes drug ganciclovir (GCV). This selective destruction of donor lymphocytes in situ will be used to abrogate the effect of graft versus host disease, if it develops.
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PMID:Adoptive immunotherapy for leukemia: donor lymphocytes transduced with the herpes simplex thymidine kinase gene for remission induction. HGTRI 0103. 945 47

Genetically modified lymphocytes have been successfully used for correction of ADA deficiency in children and in controlling graft-versus-host disease (GvHD) after allogeneic bone marrow transplantation. Low transduction efficiencies are, however, limiting for gene therapeutic strategies based on lymphocytes. In this study we compared protocols for highly efficient gene transfer into human T cells using retroviral vector-containing supernatant. We showed that infection of both human primary T cells and CD4+ Jurkat cells is most efficient on the matrix component fibronectin. Transduction was carried out with a retroviral vector encoding both the human intracytoplasmatically truncated low-affinity nerve growth factor receptor (deltaLNGFR) as a gene transfer marker and the Herpes simplex virus thymidine kinase for negative selection. Based on LNGFR expression genetically modified cells were enriched to near purity by magnetic cell sorting (MACS). Enriched cells could be shown to be highly sensitive to ganciclovir.
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PMID:Highly-efficient gene transfer with retroviral vectors into human T lymphocytes on fibronectin. 969 74

We previously demonstrated that severe graft-versus-host disease (GvHD), associated with the therapeutic infusion of donor lymphocytes after allogeneic marrow transplantation (BMT), can be efficiently controlled by the SFCMM-2-mediated expression of the herpes simplex virus thymidine kinase (HSV-tk) suicide gene into the allogeneic lymphocytes. This was achieved by selective elimination of transduced lymphocytes by ganciclovir (GCV) infusion. Despite the positive results of the pilot clinical trial, two vector-related limitations were observed. The induction of a strong immune response against genetically modified cells was observed in two patients. In addition, the only patient who developed chronic GvHD showed only partial response to ganciclovir treatment. In an attempt to overcome these limitations, we developed a new generation of vectors. The neomycin resistance (neoR) gene was removed from the SFCMM-3 and SFCMM-4 retroviral vectors. These vectors are less immunogenic and able to confer higher ganciclovir sensitivity to transduced human lymphocytes. All the vectors carry a modified form of the low-affinity nerve growth factor receptor cDNA, as cell surface selectable marker (deltaLNGFR). The vectors were compared in terms of gene transfer efficiency, and ability to confer high and specific sensitivity to ganciclovir. The SFCMM-3 vector, carrying the entire HSV-tk gene driven by the LTR promoter, allows efficient transduction of human T lymphocytes and confers the highest GCV sensitivity to transduced lymphocytes with a high and a low proliferation index. The expression of the deltaLNGFR marker allows an easier in vitro manipulation and a faster immune selection of transduced cells compared with neoR selection. Finally, the elimination of the neoR gene removes a potent immunogen from transduced lymphocytes.
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PMID:Herpes simplex virus thymidine kinase gene transfer for controlled graft-versus-host disease and graft-versus-leukemia: clinical follow-up and improved new vectors. 979 8


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