Conditional Regulation of T Cell Survival in Immunotherapy

控制转基因产物表达和/或活性的小分子可以用来启动调节细胞功能的信号通路，包括细胞死亡。由这笔赠款支持的研究已经研究了基于通过化学诱导与死亡效应分子相连的FK506结合蛋白(FKBP)的二聚化而诱导细胞凋亡的可诱导自杀基因。这种调节细胞存活的策略使用了编码人类蛋白质的转基因，应该可以避免对来自病原体的自杀基因产物的免疫反应问题。一种利用可诱导的caspase-9基因(iCasp-9)和截短的CD34分子来选择转导细胞的新结构被开发出来，以克服先前资金研究中Fas自杀基因的局限性。 句号。这项拟议的研究将在体外和临床试验中评估编码iCasp-9自杀基因的逆转录病毒载体，以调节同种异基因供体T淋巴细胞应用于患者治疗异基因造血干细胞移植(HSCT)后复发或持续的恶性肿瘤。ICasp-9的引入将使T细胞处于药物控制之下，并允许GVHD患者对其进行消融。这些研究将为临床使用化学二聚体来调节转基因功能提供洞察力，并可能识别出一种在人类中不具免疫原性的自杀基因，并可广泛应用于细胞和基因治疗。其具体目的是：1.确定编码截短CD34的逆转录病毒载体对细胞自杀的选择性标记和诱导型caspase-9(iCasp-9)的体外活性。2.确定供体过继免疫治疗的安全性、体内持久性和生物学活性 逆转录病毒修饰的T淋巴细胞表达ACD34-iCasp-9自杀基因。3.确定经修饰表达ACD34/iCasp-9自杀基因的供者T淋巴细胞是否可以通过应用合成的FKBP结合药物AP1903在发生移植物抗宿主病或其他严重毒性的患者中被去除。

Small molecules that control the expression and/or activity of transgene products can be used to initiate signaling pathways that regulate cellular functions, including cell death. Studies supported by this grant have investigated inducible suicide genes based on the induction of apoptosis through the chemical induced dimerization of FK506 binding proteins (FKBP) linked to death effector molecules. This strategy for regulating cell survival employs transgenes that encode human proteins and should avoid the problem of immune responses to suicide gene products derived from pathogens. A new construct that utilizes an inducible caspase-9 gene (iCasp-9) for cell suicide and a truncated CD34 molecule for selection of transduced cells has been developed to overcome the limitations of the Fas suicide gene studied in the prior funding period. The proposed studies will evaluate retroviral vectors encoding the iCasp-9 suicide gene in vitro and in a clinical trial to regulate allogeneic donor T lymphocytes administered to patients to treat recurrent or persistent malignancy after allogeneic hematopoietic stem cell transplant (HSCT). The introduction of iCasp-9 will bring the T cells under pharmacologic control and permit their ablation in patients with GVHD. These studies will provide insight into the clinical use of chemical dimerizing agents to regulate transgene function and may identify a suicide gene that is not immunogenic in humans and could be broadly applied in cell and gene therapy. The specific aims are: 1. To determine the in vitro activity of retroviral constructs encoding truncated CD34 as a selectable marker and inducible caspase-9 (iCasp-9) for cell suicide. 2. To determine the safety, in vivo persistence, and biologic activity of adoptive immunotherapy with donor T lymphocytes modified by retrovirus mediated gene transfer to express the ACD34-iCasp-9 suicide gene. 3. To determine if donor T lymphocytes modified to express the ACD34/iCasp-9 suicide gene can be ablated in patients who develop graft versus host disease or other serious toxicity by the administration of the synthetic FKBP binding drug AP1903.