Sekhsaria S, Malech H L
Laboratory of Host Defenses, National Institute of Allergy and Infectious Disease, National Institutes of Health, Bethesda, MD 20892.
Blood. 1993 Apr 15;81(8):2125-30.
Peripheral blood hematopoietic progenitors (PBHP) are capable of colony growth in vitro. The effect of stem cell factor (SCF), interleukin-6 (IL-6), and basic fibroblast growth factor (bFGF) on myeloid colony proliferation of PBHP was determined. PBHP purified by positive selection with CD34-specific antibody were plated in semisolid agarose with reported plateau doses of interleukin-3 (IL-3), granulocyte-macrophage colony-stimulating factor (GM-CSF), and granulocyte colony-stimulating factor (G-CSF) to enhance myeloid colony growth. Experiments then were done to examine colony growth in response to SCF or with SCF and bFGF and/or IL6. SCF alone in the absence of any other growth factors did not support colony growth. SCF at a determined optimum concentration of 100 ng/mL added to the combination of IL-3, GM-CSF, and G-CSF enhanced colony growth and size relative to proliferation in response to the latter three factors alone (from 78 to 188 total colonies/10(4) PBHP plated and from 10 to 93 large [> 200 cells] colonies/10(4) PBHP plated). Furthermore, addition of bFGF and/or IL-6 to the combination of optimum concentrations of SCF, IL-3, GM-CSF, and G-CSF further enhanced colony number and size in a dose-dependent fashion. Using the optimum combination of all growth factors, we determined that the number of myeloid colony-forming PBHP in whole blood was similar between individuals at about three colonies per milliliter whole blood. We conclude that progenitors capable of responding to the early-acting growth factor, SCF, are represented in PBHP and that the number of circulating myeloid colony-forming PBHP is likely a regulated parameter that may have an important biologic function.
外周血造血祖细胞（PBHP）能够在体外进行集落生长。测定了干细胞因子（SCF）、白细胞介素-6（IL-6）和碱性成纤维细胞生长因子（bFGF）对PBHP髓系集落增殖的影响。用CD34特异性抗体进行阳性选择纯化的PBHP接种于半固体琼脂糖中，并加入已报道的白介素-3（IL-3）、粒细胞-巨噬细胞集落刺激因子（GM-CSF）和粒细胞集落刺激因子（G-CSF）的平台剂量，以促进髓系集落生长。然后进行实验，检测SCF或SCF与bFGF和/或IL-6联合作用下的集落生长情况。单独的SCF在没有任何其他生长因子的情况下不支持集落生长。相对于单独使用后三种因子的增殖情况，将确定的最佳浓度为100 ng/mL的SCF添加到IL-3、GM-CSF和G-CSF的组合中，可增强集落生长和大小（从每10⁴个接种的PBHP产生78个至188个总集落，以及从每10⁴个接种的PBHP产生10个至93个大[>200个细胞]集落）。此外，将bFGF和/或IL-6添加到最佳浓度的SCF、IL-3、GM-CSF和G-CSF的组合中，可进一步以剂量依赖的方式增强集落数量和大小。使用所有生长因子的最佳组合，我们确定全血中能够形成髓系集落的PBHP数量在个体之间相似性约为每毫升全血三个集落。我们得出结论，能够对早期作用的生长因子SCF作出反应的祖细胞存在于PBHP中，并且循环中的能够形成髓系集落的PBHP数量可能是一个受调节的参数，可能具有重要的生物学功能。
