LONG-TERM REPOPULATION OF IRRADIATED MICE WITH LIMITING NUMBERS OF PURIFIED HEMATOPOIETIC STEM-CELLS - IN-VIVO EXPANSION OF STEM-CELL PHENOTYPE BUT NOT FUNCTION
LONG-TERM REPOPULATION OF IRRADIATED MICE WITH LIMITING NUMBERS OF PURIFIED HEMATOPOIETIC STEM-CELLS - IN-VIVO EXPANSION OF STEM-CELL PHENOTYPE BUT NOT FUNCTION
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DOI：
10.1182/blood.v85.4.1006.bloodjournal8541006
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发表时间：
1995-02-15
期刊：
影响因子：
20.3
通讯作者：
TUMAS, DB
中科院分区：
文献类型：
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作者：
SPANGRUDE, GJ;BROOKS, DM;TUMAS, DB
根据表面抗原表达(Thy-1.1(low)Lin(neg)Ly-6A/E(+))，从正常成年小鼠骨髓中分离造血干细胞，并进一步选择罗丹明123的低保留率。这种细胞群（Rh-123（低））可以介导辐射保护和移植25个细胞后的长期（大于12个月）再生。将5个基因标记的Rh-123（低）细胞与10(5)个正常骨髓细胞一起移植，结果在64%（47 / 30）的受体小鼠中，超过10%的供体细胞重建了外周血。在24周后存活的46只动物中，有10只外周血中供体来源细胞超过50%。观察到两种长期重建的一般模式：一种是在重建后5至6周观察到许多供体来源的细胞，另一种是供体来源的细胞最初很少，但随着时间的推移而扩大。这一结果表明，存在两类长期再生的造血干细胞，它们在移植过程早期的功能能力不同。另外，移植的不同解剖位置可能决定了同一类型细胞的这两种结果。作为一种测量注射细胞自我更新程度的方法，在移植后8至13个月杀死5或200个干细胞的受体，并分离原始注射细胞的thy -1,1(low)Lin(neg)Ly-6A/E（+）后代进行第二次移植。虽然观察到表达干细胞表面表型的细胞的数值扩增，以及在集落形成单位-脾脏试验中的活性，但与从正常动物中新鲜分离的细胞相比，扩增的细胞在辐射防护和长期重建试验中明显落后。这一结果表明，在干细胞扩增实验中，细胞表面抗原表达并不是干细胞功能的合适指标。
Hematopoietic stem cells were isolated from normal adult mouse bone marrow based on surface antigen expression (Thy-1.1(low)Lin(neg)Ly-6A/E(+)) and further selected for low retention of rhodamine 123. This population of cells (Rh-123(low)) could mediate radioprotection and long-term (:greater than 12 months) repopulation after transplantation of as few as 25 cells. Transfer of five genetically marked Rh-123(low) cells in the presence of 10(5) normal bone marrow cells resulted in reconstitution of peripheral blood by greater than 10% donor cells in 64% (30 of 47) of recipient mice. Of 46 animals surviving after 24 weeks, 10 had over 50% donor-derived cells in peripheral blood. Two general patterns of long-term reconstitution were observed: one in which many donor-derived cells were observed 5 to 6 weeks after reconstitution and another in which donor-derived cells were rare initially but expanded with time. This result suggests that two classes of long-term repopulating hematopoietic stem cells exist, differing in their ability to function early in the course of transplantation. Alternatively, distinct anatomic sites of engraftment may dictate these two outcomes from a single type of cell. As an approach to measure the extent of self-renewal by the injected cells, recipients of five or 200 stem cells were killed 8 to 13 months after the transplants, and Thy-1,1(low)Lin(neg)Ly-6A/E(+) progeny of the original injected cells were isolated for a second transplant. While a numerical expansion of cells expressing the cell surface phenotype of stem cells was observed, along with activity in the colony-forming unit-spleen assay, the expanded cells were vastly inferior in radioprotection and long-term reconstitution assays when compared with cells freshly isolated from normal animals. This result demonstrates that in stem cell expansion experiments, cell surface antigen expression is not an appropriate indicator of stem cell function.