Immunosupression-Resistant Gene Modified Donor T Cells

免疫抑制抗性基因修饰供体 T 细胞

• 批准号: 7060417
• 负责人: GEORGE Earl GEORGES
• 金额: $ 33.36万
• 依托单位: FRED HUTCHINSON CANCER RESEARCH CENTER
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-05-01 至 2010-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7060417
• 关键词: Lentivirus; T lymphocyte; bone marrow; cytotoxicity; dogs; drug resistance; ganciclovir; gene therapy; graft versus host disease; hematopoietic stem cells; hematopoietic tissue transplantation; histocompatibility; homologous transplantation; immune response genes; lymphocyte proliferation; mycophenolate mofetil; nonhuman therapy evaluation; stem cell transplantation; thymidine kinase; transfection; transfection /expression vector; whole body irradiation effect

DESCRIPTION (provided by applicant): Allogeneic hematopoietic cell transplantation (HCT) is a form of cancer immunotherapy that relies on donor T cells to facilitate engraftment and induce the beneficial the graft-versus-leukemia effect. However, alloreactive donor T cells can also cause fatal graft-versus-host disease (GVHD). Genetic modification of donor T cells with a "suicide" gene, herpes simplex virus thymidine kinase (HSV-tk), has the potential to significantly improve the safety of allogeneic HCT by killing the alloreactive, GVHD-causing T cells with ganciclovir. To date, clinical studies of HSV-tk modified donor T cells infused after allogeneic HCT have shown very limited in vivo function. We propose a novel strategy to favor the in vivo immune function of genetically modified T cells in a large animal model of allogeneic HCT. The hypothesis is that lentiviral transduction of donor T cells with an immunosuppression drug-resistance gene conferring a selective proliferative advantage over host immune cells can significantly improve the in vivo function of the gene-modified T cells. We will evaluate a bicistronic lentiviral vector expressing HSV-tk and a dominant mutant inosine monophosphate dehydrogenase II (IMPDH*) gene, which renders transduced T cells sensitive to ganciclovir and resistant to the immunosuppressive drug mycophenolate mofetil (MMF). Using the dog model of MHC-mismatched HCT, we will test the in vivo function of MMF-resistant donor T cells to facilitate engraftment of T-cell-depleted (TCD) donor marrow after total body irradiation (TBI). Treatment of recipients with MMF after infusion of IMPDH* transduced donor T-cells would inhibit immune responses to the gene modified T cells and give a proliferative advantage to the transduced T cells. This approach allows the graft-versus-host function of the MMF-resistant donor T cells while suppressing the host-versus-graft response. Aim 1 will study the in vivo effectiveness of the IMPDH* transduced donor T cells to facilitate engraftment after myeloablative TBI. Dogs with GVHD will be treated with ganciclovir. Aim 2 will decrease the TBI dose needed to engraft TCD marrow by treating with a combination postgrafting cyclosporine and MMF and infusion of MMF- and cyclosporine-resistant T cells. After engraftment, ganciclovir will be given to control GVHD. The theme of this project is to apply a gene therapy strategy of immunosuppressive drug resistance to manipulate the immune function in favor of donor immune cells after HCT. Results from these studies have the strong potential to be directly translated to future gene therapy clinical trials.

描述（由申请人提供）：同种异体造血细胞移植（HCT）是癌症免疫疗法的一种形式，它依赖于供体 T 细胞来促进移植并诱导有益的移植物抗白血病效应。然而，同种异体反应性供体 T 细胞也会引起致命的移植物抗宿主病 (GVHD)。用“自杀”基因——单纯疱疹病毒胸苷激酶（HSV-tk）对供体 T 细胞进行基因改造，通过用更昔洛韦杀死引起 GVHD 的同种异体反应性 T 细胞，有可能显着提高同种异体 HCT 的安全性。迄今为止，同种异体 HCT 后输注的 HSV-tk 修饰供体 T 细胞的临床研究显示其体内功能非常有限。我们提出了一种新策略，有利于转基因 T 细胞在同种异体 HCT 大型动物模型中的体内免疫功能。该假设认为，慢病毒转导带有免疫抑制耐药基因的供体 T 细胞，赋予其相对于宿主免疫细胞的选择性增殖优势，可以显着改善基因修饰 T 细胞的体内功能。我们将评估表达 HSV-tk 和显性突变肌苷单磷酸脱氢酶 II (IMPDH*) 基因的双顺反子慢病毒载体，该基因使转导的 T 细胞对更昔洛韦敏感，并对免疫抑制药物吗替麦考酚酯 (MMF) 具有抗性。使用 MHC 不匹配的 HCT 狗模型，我们将测试 MMF 抗性供体 T 细胞的体内功能，以促进全身照射 (TBI) 后 T 细胞耗尽 (TCD) 供体骨髓的植入。在输注 IMPDH* 转导的供体 T 细胞后，用 MMF 治疗受体将抑制对基因修饰 T 细胞的免疫反应，并为转导的 T 细胞提供增殖优势。这种方法允许 MMF 抗性供体 T 细胞发挥移植物抗宿主功能，同时抑制宿主抗移植物反应。目标 1 将研究 IMPDH* 转导的供体 T 细胞在清髓性 TBI 后促进植入的体内有效性。患有 GVHD 的狗将接受更昔洛韦治疗。目标 2 将通过移植后环孢素和 MMF 联合治疗以及输注 MMF 和环孢素抗性 T 细胞来减少移植 TCD 骨髓所需的 TBI 剂量。植入后，将给予更昔洛韦来控制 GVHD。该项目的主题是应用免疫抑制耐药性的基因治疗策略来操纵HCT后的免疫功能，使其有利于供体免疫细胞。这些研究的结果有很大潜力直接转化为未来的基因治疗临床试验。