Noort W A, Willemze R, Falkenburg J H
Department of Hematology, Leiden University Medical Centre, The Netherlands.
Bone Marrow Transplant. 1998 Jul;22 Suppl 1:S58-60.
The repopulating ability and homing potential of CD34+ cells isolated from either bone marrow (BM) or umbilical cord blood (UCB) was compared in NOD/SCID mice. Mice were sublethally irradiated (3.5 Gy) and within 24 h transplanted i.v. with 10(5)-10(6) CD34+ cells. Four weeks post-transplantation blood was collected from the tail vein for detection of human cells and after 6-7 weeks the mice were sacrificed and blood, BM, thymus, lymph nodes, spleen, liver, lung and kidney were harvested and single cells suspensions were made. Human cells were detected by flow cytometry, and staining was performed for CD34, CD45, and markers of the myeloid, and lymphoid lineages. CD34+ cells from UCB successfully engrafted into the NOD/SCID mice. Eighty-five percent of cells in BM of the mice were of human origin, depending on the dose of cells injected. In all other organs these percentages were always lower, and maximally 63, 13, 3 and 2% in spleen, liver, lung and kidney, respectively. Transplantation of CD34+ cells isolated from human BM, on the other hand, resulted in a very low percentage of human cells after 6-7 weeks of transplantation, not exceeding 3% of the cell suspension. Whether this difference in repopulating ability can be explained by an intrinsic qualitative difference or by differences in quantity of stem cells within the CD34+ compartment from UCB or BM remains to be determined.
在NOD/SCID小鼠中比较了从骨髓（BM）或脐带血（UCB）分离的CD34+细胞的重新增殖能力和归巢潜力。小鼠接受亚致死剂量照射（3.5 Gy），并在24小时内通过静脉注射移植10⁵ - 10⁶个CD34+细胞。移植后4周从尾静脉采集血液以检测人类细胞，6 - 7周后处死小鼠，采集血液、骨髓、胸腺、淋巴结、脾脏、肝脏、肺和肾脏并制成单细胞悬液。通过流式细胞术检测人类细胞，并对CD34、CD45以及髓系和淋巴系标志物进行染色。来自UCB的CD34+细胞成功植入NOD/SCID小鼠体内。根据注射的细胞剂量，小鼠骨髓中85%的细胞来源于人类。在所有其他器官中，这些百分比始终较低，脾脏、肝脏、肺和肾脏中分别最高为63%、13%、3%和2%。另一方面，移植从人类BM分离的CD34+细胞后，移植6 - 7周后人类细胞的百分比非常低，不超过细胞悬液的3%。这种重新增殖能力的差异是由内在的质量差异还是由UCB或BM的CD34+细胞区内干细胞数量的差异所解释，仍有待确定。
