EXPANSION OF STEM CELLS FROM CD34 ENRICHED POPULATIONS

造血细胞扩增的临床前和临床数据显示， 灌注骨髓原始细胞输出的明显差异 单核细胞培养物和静态CD 34富集细胞培养物。相位 我的研究解决了CD 34 +lin-细胞的扩增，重点是LTC- IC输出，使用灌注培养环境作为模型系统。 灌注速率和已知生长因子组合的操作， 浓度在增加LTC-IC输出方面无效。然而，在这方面， CD 34 +lin-细胞与间质的接触诱导了50-100 kD的可溶性 在无基质培养物中增加LTC-IC输出的活性。相 建议II用于识别和表征可溶性因子 负责这项活动。RT-PCR将用于检查 直接接触CD 34 +lin后已知生长因子的表达， 细胞与基质。此外，差异mRNA显示将是 用于鉴定接触诱导的基因，包括潜在的新基因， 干细胞因子这种方法还有一个额外的好处， 识别干细胞归巢和激活相关基因。 确定具有LTC-IC支持活性的因素， 干细胞扩增的重要研究和临床应用， 离体基因治疗。 拟议的商业应用： 拟议的研究将解决mRNA表达的变化， 在直接接触干细胞和基质细胞时， 其他.这种方法的目标是一种可溶性因子，已知是 诱导，这支持LTC-IC在纯化的细胞培养物中的生长。 这样一个因素将在研究和开发方面具有巨大的商业潜力。 细胞扩增和基因治疗的临床市场。的方法 所描述的也将产生关于茎诱导的其他基因的信息- 基质细胞接触，这可能是有用的， 干细胞归巢和动员的重要商业领域。

Pre-clinical and clinical data on hematopoietic cell expansion have shown clear differences in primitive cell output from perfused bone marrow mononuclear cell cultures and static CD34-enriched cell cultures. A Phase I study addressed the expansion of CD34+lin- cells, with emphasis on LTC- IC output, using the perfused culture environment as a model system. Manipulation of perfusion rates and known growth factor combinations and concentrations was not effective in increasing LTC-IC output. However, contact between CD34+lin- cells and stroma induced a 50-100 kD soluble activity which increased LTC-IC output in stromal-free cultures. Phase II is proposed to identify and characterize the soluble factor(s) responsible for this activity. RT-PCR will be used to examine changes in the expression of known growth factors after direct contact of CD34+lin- cells with stroma. In addition, differential mRNA display will be utilized to identify contact-induced genes, including potentially novel stem cell factors. This approach has the added benefit of potentially identifying genes involved in stem cell homing and activation. Identification of the factor(s) with LTC-IC supportive activity has important research and clinical applications for stem cell expansion and ex vivo gene therapy. PROPOSED COMMERCIAL APPLICATIONS: The proposed research will address the changes in mRNA expression that are induced in stem and stromal cells upon direct contact with each other. The target of this approach is a soluble factor, known to be induced, which supports the growth of LTC-IC in purified cell cultures. Such a factor would have great commercial potential in both research and clinical markets of cell expansion and gene therapy. The approach described will also yield information on other genes induced by stem- stromal cell contact, which could potentially be useful in the commercially important areas of stem cell homing and mobilization.