Cesana C, Carlo-Stella C, Mangoni L, Regazzi E, Garau D, Sammarelli G, Caramatti C, Almici C, Rizzoli V
Department of Hematology, University of Parma, Italy.
Stem Cells. 1997;15(3):207-13. doi: 10.1002/stem.150207.
The existence of primitive hematopoietic progenitors in mobilized peripheral blood is suggested by clinical, phenotypic and in vitro cell culture evidences. In order to quantify primitive progenitors, 32 leukaphereses from 15 patients with lymphoid malignancies were investigated for the growth of multilineage colony-forming units (CFU-Mix), erythroid burst-forming units (BFU-E) and granulocyte-macrophage colony-forming units (CFU-GM) in the absence or presence of recombinant stem cell factor (SCF), a cytokine which selectively controls stem cell self-renewal, proliferation and differentiation. Primitive progenitors were also quantitated by means of a long-term assay which allows the growth of cells capable of initiating and sustaining hematopoiesis in long-term culture (LTC-IC). Addition of SCF (50 ng/ml) to methyl-cellulose cultures stimulated with maximal concentrations of G-CSF, GM-CSF, interleukin 3 and erythropoietin significantly increased the growth (mean +/- SE) of CFU-Mix (7.7 +/- 1.7 versus 2.4 +/- 0.6, p < or = 0.0001), BFU-E (47 +/- 10 versus 32 +/- 6, p < or = 0.002) and CFU-GM (173 +/- 31 versus 112 +/- 20, p < or = 0.0001). Mean (+/- SE) percentages of SCF-dependent CFU-Mix, BFU-E and CFU-GM were 60 +/- 5%, 19 +/- 5%, and 33 +/- 4%, respectively. Mean (+/- SE) LTC-IC growth per 2 x 10(6) nucleated cells was 221 +/- 53 (range, 2 to 704). Linear regression analysis demonstrated a statistically significant correlation (r = .87; p < or = 0.0001) between LTC-IC and SCF-dependent progenitors. In conclusion, our data suggest that: A) the optimal quantification of mobilized progenitors requires supplementation of methylcellulose cultures with SCF, and B) in vitro detection of SCF-dependent progenitors might represent a reliable and technically simple method to assess the primitive progenitor cell content of blood cell autografts. Such in vitro evaluation of immature hematopoietic progenitors might be clinically relevant for predicting the reconstituting potential of autografts.
临床、表型及体外细胞培养证据均提示动员外周血中存在原始造血祖细胞。为了对原始祖细胞进行定量分析，研究人员对15例淋巴系统恶性肿瘤患者的32次白细胞分离产物进行了研究，观察在有无重组干细胞因子（SCF）存在的情况下多系集落形成单位（CFU-Mix）、红系爆式集落形成单位（BFU-E）和粒-巨噬细胞集落形成单位（CFU-GM）的生长情况。SCF是一种能选择性调控干细胞自我更新、增殖及分化的细胞因子。原始祖细胞还通过一种长期检测方法进行定量，该方法可使能够在长期培养（LTC-IC）中启动并维持造血的细胞生长。向用最大浓度的G-CSF、GM-CSF、白细胞介素3和促红细胞生成素刺激的甲基纤维素培养物中添加SCF（50 ng/ml），可显著增加CFU-Mix（7.7±1.7对2.4±0.6，p≤0.0001）、BFU-E（47±10对32±6，p≤0.002）和CFU-GM（173±31对112±20，p≤0.0001）的生长。依赖SCF的CFU-Mix、BFU-E和CFU-GM的平均（±SE）百分比分别为60±5%、19±5%和33±4%。每2×10⁶有核细胞的平均（±SE）LTC-IC生长为221±53（范围为2至704）。线性回归分析表明LTC-IC与依赖SCF的祖细胞之间存在统计学显著相关性（r = 0.87；p≤0.0001）。总之，我们的数据表明：A）对动员的祖细胞进行最佳定量需要在甲基纤维素培养物中补充SCF，并且B）体外检测依赖SCF的祖细胞可能是一种评估血细胞自体移植物中原始祖细胞含量的可靠且技术简单的方法。这种对未成熟造血祖细胞的体外评估可能在临床上与预测自体移植物的重建潜力相关。
