CORE--ANIMAL MODELS

镰状细胞病的成功基因治疗的发展将在很大程度上依赖于动物实验，以建立这种方法的临床可行性。这些动物模型对于评估用于人类造血干细胞转导的新方法、用于评估用于调节血红蛋白转换的基因治疗方法以及用于设计用于选择性扩增遗传修饰的造血干细胞的临床策略是至关重要的。用人类造血细胞重建非肥胖糖尿病免疫缺陷小鼠已被证明是人类干细胞功能的重要测定。该模型系统将用于评估各种逆转录病毒载体和转导亲方案。该系统还将用于通过靶向直接来源于正常患者和镰状细胞性贫血患者的造血细胞重建来直接评估潜在的治疗载体。该核心将提供的第二个系统是在酵母人工染色体上含有人类β-珠蛋白簇的转基因小鼠。这些小鼠提供了一个体内模型，以研究胎儿到成人珠蛋白合成的转录转换。各种转录因子及其调节剂将在这个模型中进行研究，以确定胎儿珠蛋白的合成是否可以在成人发育阶段重新激活。该核心提供的第三个模型是由我们在国家心肺和血液研究所的合作者提供的恒河猴移植模型。这种非人灵长类动物模型将用于研究有效干细胞基因转移的新方法，以评估使用药物选择扩增少数遗传改变的干细胞的功效（项目4），并在严格和临床相关的模型中测试各种镰状细胞治疗载体。该核心提供对这些动物模型的集中访问，并提供用于评估这些系统中的基因转移终点的标准化测定。此外，共同的基因治疗目标，汇聚在这个核心将继续作为一个重要的来源，合作之间的相互作用的研究在程序项目。

The development of successful gene therapy for sickle cell disease will rely heavily upon animal experimentation in order to establish the clinical feasibility of this approach. These animal models are critical for assessing new approaches for transduction of human hematopoietic stem cells, for evaluating gene therapy approaches for modulating hemoglobin switching, and for designing clinical strategies for the selective amplification of genetically-modified hematopoietic stem cells. Repopulating of non-obese diabetic immunodeficient mice with human hematopoietic cells has proven to be an important assay for human stem cell function. This model system will be used to evaluate various retroviral vectors and transduction pro protocols . This system will also be used to directly evaluate potentially therapeutic vectors by targeting repopulating hematopoietic cells derived directly from normal patients and those with sickle cell anemia. A second system that will be provided by this core is transgenic mice that contain the human beta-globin cluster on a yeast artificial chromosome. These mice provide an in vivo model to study the transcriptional switching of fetal to adult globin synthesis. Various transcription factors and modulators thereof will be studied in this models to determine if fetal globin synthesis can be reactivated in the adult developmental stage. The third model provided by this core is a Rhesus macaque transplant model provided by our collaborators at the National Heart Lung and Blood Institute. This non-human primate model will be utilized to study novel approaches for efficient stem cell gene transfer to evaluate the efficacy of using drug selection to amplify a minority of genetically-altered stem cells (Project 4), and to test various sickle cell therapeutic vectors in a stringent and clinically relevant model. This core provides centralized access to these animal models, and provides standardized assays for evaluating gene transfer endpoints in these systems. Furthermore, the common gene therapy objectives that converge in this core will continue to serve as an important source of collaborative interactions between the investigations in the program project.