rhIL－6、rhGM－CSF和rhEPO对人骨髓造血干细胞的调节作用

重组人白细胞介素６（ｒｈＩＬ－６）和重组人粒—单细胞集落刺激因子（ｒｈＧＭ－ＣＳＦ）与正常人造血干细胞培养１周后，ｒｈＩＬ－６组干细胞数增至４．７±０．７倍；ｒｈＧＭ－ＣＳＦ组增至９．３±１．０倍；ｒｈＩＬ－６＋ＧＭ—ＣＳＦ组增至１３．４±３．３倍。与对照组比较，Ｐ均＜０．０１．造血干细胞ＣＦＵ－Ｅ集落分析：ｒｈＩＬ－６组未见ＣＦＵ－Ｅ集落形成；ｒｈＩＬ－６＋ＥＰＯ组则ＣＦＵ－Ｅ集落明显高于ｒｈＥＰＯ组，ｐ＜０．０１．造血干细胞ＣＦＵ－Ｍｉｘ集落分析：ｒｈＩＬ－６组和ｒｈＧＭ－ＣＳＦ组可见ＣＦＵ－ＧＭ浆落，无ＣＦＵ＋Ｍｉｘ集落形成；ｒｈＩＬ－６＋ＧＭ－ＣＳＦ组有ＣＦＵ－Ｍｉｘ集落形成；ｒｂＩＬ－６＋ＧＭ－ＣＳＦ＋ＥＰＯ联合应用，有ＣＦＵ－ｎ，ｍ，Ｍ，Ｅ混合集落数增多。实验结果提示ｒｈＩＬ－６对造血干细胞有直接的刺激作用，主要刺激粒—单系组细胞增殖。ｒｈＩＬ－６与ｒｈＥＰＯ有协同作用，能促进ｒｈＥＰＯ刺激红系祖细胞的作用。ｒｈＩＬ－６与ｒｈＧＭ－ＣＳＦ亦有协同作用，可以刺激多能干细胞形成混合集落。     

Studies on human CFU-Mix microvolume culture by use of limiting dilution assay

By use of limiting dilution assay we investigated the bipotent and pluripotent hemopoietic progenitor cells (CFU-Mix) from 21 normal adults, cultured for 32 times. The CFU-Mix counts were 35.7 colonies/10⁶ bone marrow cells. According to different cellular elements they could be divided into 5 groups, namely GEMM, GE, GL, GMeg and GMϕ. It was suggested that differentiation of the stem cell is of stochastic process, influenced by different hemopoietic growth factors and cellular microenvironment. Our model seems to be suitable for studying differentiation of the stem cells. The rates of³H-TdR and^{55 + 59}Fe incorporation were determined, and the 2nd day of culture was found to be the delayed stage of cell growth.     

Human FLT3 ligand acts on myeloid as well as multipotential progenitors derived from purified CD34+ blood progenitors expressing different levels of c-kit protein

Abstract: We studied the effect of human flt3/flk2 ligand (FL) on the proliferation and differentiation of purified CD34⁺ blood progenitors which express different levels of c-kit protein in clonal cell culture in comparison with that of stem cell factor (SCF). FL alone did not support significant colony formation. However, FL significantly enhanced neutrophil colony (CFU–G) formation in the presence of granulocyte-colony stimulating factor (G–CSF) by peripheral blood (PB)-derived CD34⁺c-kit^? cells which contained a large number of CFU–G. In addition, FL could synergistically increase the number of CFU–G supported by a combination of interleukin (IL)-3 and G–CSF, as did SCF. As we reported previously, SCF showed a significant burst-promoting activity (BPA). In contrast, FL did not exhibit any BPA on PB-derived CD34⁺c-kit^high cells in which erythroid-burst (BFU-E) was highly enriched. However, FL could synergize with IL-3 or GM–CSF in support of erythrocyte-containing mixed (E-Mix) colony by PB-derived CD34⁺c-kit^{high or low} cells in the presence of Epo. Replating of E-Mix colonies derived from CD34⁺c-kit^high cells supported by IL-3+Epo+SCF yielded more secondary colonies than those supported by IL-3+Epo or IL-3+Epo+FL. When PB-derived CD34⁺c-kit^low cells which represent a more immature population than CD34⁺c-kit^high cells were used as the target, number of secondary colonies supported by IL-3+Epo, IL-3+Epo+SCF or IL-3+Epo+FL was comparable. However, the number of lineages expressed in the secondary culture was significantly larger in the primary culture containing IL-3+Epo+FL than in that containing IL-3+Epo. These results suggest that FL not only acts on neutrophilic progenitors, but also on more immature multipotential progenitors.     

Action of human interleukin-4 and stem cell factor on erythroid and mixed colony formation by peripheral blood-derived CD34+c-kithigh or CD34+c-kitlow cells

We studied the interaction of interleukin (IL)-4 and other burst-promoting activity (BPA) factors, such as IL-3, granulocyte/macrophage colony-stimulating factor (GM-CSF), IL-9 and stem cell factor (SCF), on erythroid burst-forming unit (BFU-E) and erythrocyte-containing mixed (CFU-Mix) colony formation in serum-free culture. IL-4 alone did not support mixed colony formation in the presence of erythropoietin (Epo). However, IL-4 showed weak but significant BPA when peripheral blood (PB)-derived CD34⁺c-kit^low cells were used as the target population. The BPA of IL-4 was much weaker than that of IL-3, which exerted the most potent activity, as previously reported. When CD34⁺c-kit^high cells were used as the target, four factors known to have BPA, IL-3, GM-CSF, IL-9 and SCF, could express BPA. In contrast, IL-4 alone failed to support erythroid burst formation. Interestingly, IL-4 showed a remarkable enhancing effect with SCF in promoting the development of erythroid burst and erythrocyte-containing mixed colonies from CD34⁺c-kit^low and CD34⁺c-kit^high cells. Delayed addition of SCF + Epo or IL-4+Epo to the cultures initiated with either IL-4 or SCF alone clearly demonstrated that SCF was a survival factor for both BFU-E and CFU-Mix progenitors. In contrast, the survival effect of IL-4 was much weaker than that of SCF, and appeared to be more important for progenitors derived from CD34⁺c-kit^low cells than for those derived from CD34⁺c-kit^high cells. It was recently reported that CD34⁺c-kit^low cells represent a more primitive population than CD34⁺c-kit^high cells. Taken together, these results suggest that IL-4 helps to recruit primitive progenitor cells in the presence of SCF.     

Detection of surface antigen expression of pre- and postcultured normal adult’s bone marrow cells by using ABC technique and its significance

Summary The expression of surface antigens on both normal adult’s bone marrow and multipotential progenitor cells (CFU-Mix) was detected by use of ABC technique. The culture system of CFU-Mix was an ideal model for studying the differentiation direction of hematopoietic cells. The monoclonal antibodies (McAb) CD₃, CD₄, CD₈specific for T-lymphocytic lineage, CD₂₂ for B-lymphocytic lineage and CD₁₁, CD₁₃, CD₁₄ for granulocytomonocytic lineage were all demonstrated in certain proportion in cultured CFU-Mix, which might be associated with the control of hematopoiesis. A decrease in the positive rate of OKT, and CD₃₄ in cultured cells might be related to the differentiation of hematopoietic cells. SZ-2 and SZ-21 could contribute to the identification of the presence of megakaryocytes in CFU-Mix.     

Studies on the relationship between leukemic fibroblast colony forming cell and hemopoietic cells

Summary 36 patients with leukemia, including AML, CML and ALL were studied. Fibroblast colony forming cells (CFU-F) in patients with different types of leukemia were less than in normal adults (P<0.05-0.001). There was no correlation observed between CFU-F and CFU-Mix/L-CFU in normal adults and leukemic patients (P>0.05). It was found that CFU-F is a single clone not, originating from hemopoietic cells. After fetal muscular conditioned media were added, we observed that myelogenous leukemic cells showed the ability to adhere to the bottom of the dish, indicating the existence of quantitative and qualitative defects of CFU-F in leukemia. The mechanism and clinical significance of this phenomenon are discussed.     

人多能造血祖细胞与前红系祖细胞体外培养的研究

本文以Messner培养体系为基础,并加以改良,在一个培养体系内培养出了人多能造血祖细胞(CFU-Mix)和前红系祖细胞(BFU-E),集落产率高于文献报道。同时,我们改进了细胞离心方法,使单个细胞集落形态完整,记数准确,为研究造血干细胞的分化提供了条件。