Schibler K R, Li Y, Ohls R K, Nye N C, Durham M C, White W, Liechty K W, Le T, Christensen R D
Division of Human Development and Aging, University of Utah School of Medicine, Salt Lake City 84132.
Blood. 1994 Dec 1;84(11):3679-84.
Hematopoietic progenitors obtained from the bone marrow of healthy adults fail to undergo clonogenic maturation in vitro if a source of hematopoietic growth factors is not included in the culture dishes. In contrast, a fraction of similarly purified progenitors obtained from umbilical cord blood undergo clonogenic maturation even in the absence of added growth factors. We postulated that production of hematopoietic growth factors within the culture dishes containing the progenitors of umbilical cord blood origin might be responsible. We postulated further, that this production might be by non-progenitor cells co-plated along with the progenitors, or alternatively by CD34+ cells themselves, or by cells clonally derived from CD34+ cells. To test these possibilities we first assessed the effect of including in the cultures neutralizing antibody directed against various growth factors. Inclusion of anti-granulocyte macrophage colony-stimulating factor (GM-CSF) and anti-interleukin-3 (IL-3) (but not anti-IL-2) significantly reduced the growth factor independence of cord blood progenitors (P < .005 and P < .01). Inclusion of both anti-GM-CSF and anti-IL-3 almost completely ablated the spontaneous colony growth (P < .001). Inclusion of IL-10 also reduced, in a concentration-dependent fashion, the spontaneous generation of umbilical cord blood-derived colonies. Transcripts for GM-CSF and IL-3 were detected, by reverse transcriptase-polymerase chain reaction (RT-PCR), in the CD34+ cells from cord blood and from adult marrow. When plated without added growth factors, however, the CD34+ cells of adult marrow origin failed to produce colonies, whereas 6% of cord blood CD34+ cells similarly cultured did so. When these growth factor independent colonies were plucked from culture, transcripts for GM-CSF and IL-3 were identified in all. We conclude that production of GM-CSF and IL-3 occurs within culture dishes containing hematopoietic progenitors of umbilical cord origin, and that this explains some of their apparently unique features of in vitro growth.
如果培养皿中不添加造血生长因子来源，从健康成年人骨髓中获得的造血祖细胞在体外无法进行克隆成熟。相比之下，从脐带血中获得的一部分经过类似纯化的祖细胞即使在不添加生长因子的情况下也能进行克隆成熟。我们推测，含有脐带血来源祖细胞的培养皿中造血生长因子的产生可能是原因所在。我们进一步推测，这种产生可能是由与祖细胞一起共培养的非祖细胞完成的，或者是由CD34+细胞自身，或者是由CD34+细胞克隆衍生的细胞完成的。为了验证这些可能性，我们首先评估了在培养物中加入针对各种生长因子的中和抗体所产生的影响。加入抗粒细胞巨噬细胞集落刺激因子（GM-CSF）和抗白细胞介素-3（IL-3）（但不包括抗IL-2）显著降低了脐带血祖细胞对生长因子的依赖性（P < 0.005和P < 0.01）。同时加入抗GM-CSF和抗IL-3几乎完全消除了自发集落生长（P < 0.001）。加入IL-10也以浓度依赖的方式减少了脐带血来源集落的自发产生。通过逆转录聚合酶链反应（RT-PCR）在脐带血和成人骨髓的CD34+细胞中检测到了GM-CSF和IL-3的转录本。然而，当不添加生长因子进行接种时，成人骨髓来源的CD34+细胞无法产生集落，但同样培养的脐带血CD34+细胞中有6%能够产生集落。当从培养物中挑选出这些不依赖生长因子的集落时，在所有集落中都鉴定出了GM-CSF和IL-3的转录本。我们得出结论，GM-CSF和IL-3在含有脐带来源造血祖细胞的培养皿中产生，这解释了它们在体外生长的一些明显独特的特征。
