EX VIVO EXPANSION OF SELECTED STEM AND PROGENITOR CELLS

早期祖细胞的体外分离 去除白血病细胞很难获得足够的 适时造血干、祖细胞数量 重建。因为潜在正常干细胞的数量只有 收获的一小部分，分馏程序本身 经常限制可用于治疗的干细胞和祖细胞的数量 自体移植，从而延长了术后中性粒细胞减少的时间 移植患者的准备治疗。在这个子项目中，我们 将利用持续灌流的体外造血培养系统 确定体外扩增的动力学和动力学。 早期，从CML患者中选择造血细胞。OUT首要目标 将产生足够数量的祖细胞和LTCIC细胞来 推动快速稳定嫁接。此外，我们还将研究 Bcr-abl基因在原代祖细胞克隆中的表达 细胞，并从祖细胞产生的维持和扩增 LTCIC细胞在这些灌流培养中，以确定在多大程度上 这种白血病嵌合信息的表达存在于这些细胞中。 同样，我们将评估BCR-ABL阴性初选的克隆性 祖细胞和LTCICs，以了解是否可以获得“白血病前期”Ph克隆 在这些样本中检测到，以及克隆种群是否消失 或在灌流培养后出现。如果这些研究的结果 令人鼓舞的是，对于任何一种特定的净化或选择技术，我们 将启动一项临床试验，在该试验中，选定的细胞将在 体内在临床规模的灌流生物反应器系统中，然后再回输 进入消融性化疗后的患者。这一方法将 然后直接并入临床自体移植 项目，由Deisseroth博士指导。

Ex vivo fractionation of early progenitor cells for the purpose of removing leukemic cells presents difficulties in obtaining sufficient numbers of stem and progenitor cells for timely hematopoietic reconstitution. Since the number of potentially normal stem cells is only a fraction of those harvested, the fractionation procedures themselves often limit the number of stem and progenitor cells available for autotransplantation, thus prolonging the period of neutropenia following preparative therapy in the transplant patients. In this subproject, we will utilize a continuous perfusion ex vivo hematopoietic culture system to define the kinetics and dynamics of ex vivo hematopoietic expansion of early, selected hematopoietic cells from CML patients. Out primary goal will be to generate sufficient numbers of progenitor and LTCIC cells to promote rapid and stable engraftment. In addition, we will study the expression of bcr-abl mRNA in colonies derived from primary progenitor cells, and from the progenitor cells produced by maintained and expanded LTCIC cells in these perfusion cultures, to determine to what extent expression of this leukemic chimeric message is present in these cells. Similarly, we will evaluate the clonality of bcr-abl negative primary progenitors and LTCICs, to see whether a "preleukemic" Ph- clone can be detected in these samples, and whether a clonal population disappears or emerges following perfusion culture. If the results of these studies are encouraging, for any one specific purging or selection technique, we will initiate a clinical trial in which selected cells will be expanded ex vivo in a clinical scale perfusion bioreactor system, and then reinfused into the patients following ablative chemotherapy. This approach will then be directly incorporated into the clinical autologous transplantation programs, as directed by Dr. Deisseroth.