THE EFFECT OF STEM CELL FACTOR, INTERLEUKIN-6 AND ERYTHROPOIETIN ON EXPANSION OF CD34~ CELLS FROM HUMAN UMBILICAL CORD BLOOD

CD34 cells from human umbilical cord blood were purified by Dynal beads M-450 CD34 immunoselection system and cultured in the presence of various cytokines alone or in combination, including stem cell factor (SCF), interleukin-6 (IL-6) and erythropoietin (EPO). The results revealed that: (D In methylcellulose culture, the plating efficiencies of purified cord blood CD34 cells were much different when stimulated by various cytokines. IL-6 alone had the lowest colo-ny yield, while the combination of SCF, IL-6 and EPO had the highest yield. ② In the suspension culture, IL-6 alone or IL-6 EPO had little expanding effect on cord blood CD34 celis, the other cytokine combinations could expand cord blood CD34 celis at different Ievels. Among them, the combination of SCF, IL-6 and EPO had the maximal expanding effect on cord blood CD34 celis, the number of progenitor celis peaked at day 21, about 29-fold increase and nucleated celis increased approximately 3676-fold at day 28. The expanding effect of the     

Tempo of hematologic recovery correlates with peripheral blood CD34+ cell level in patients undergoing stem cell mobilization

This study was undertaken to evaluate the relationship between the time to recovery of peripheral blood counts and CD34+ cells in the peripheral blood (PB) and apheresis collections of patients undergoing intensive chemotherapy followed by rhG-CSF. Twenty-three patients with a median age of 42 years (range 17–64) with malignancies underwent peripheral blood stem cell (PBSC) collection after cyclophosphamide (CY) 4 g/m² and etoposide (600 mg/m²) followed by rhG-CSF (10 μg/kg/day). The WBC, platelet counts, CD34+ cell counts per ml of PB, and CD34+ cells in apheresis products were followed in all patients. The relationship of the time to recovery of WBC >1,000/μl, >3,000/μl, >10,000/μl and platelets >20,000/μl and 50,000/μl was compared to the average daily CD34+ cells/ml in each patient using the Spearman Correlation test. The tempo of recovery of WBC and platelets were highly correlated with the average CD34+ cell count in blood. In order to derive some useful guidelines for the timing of apheresis, the patients were divided into two groups, early recover (ER) and late recover (LR) based on the median time (day 10) to reach WBC count greater than 1,000/μl. ER patients had an average daily PB CD34+ cell count of 9.04 × 10⁴/ml (range 0.44–17.5) and a median yield of CD34+ cells of 10.43 × 10⁶/kg (range 0.60–25.95) compared to LR patients, who had 1.87 × 10⁴/ml (range 0.32–5.44) in the PB (P = .001) and a yield 3.20 × 10⁶/kg CD34+ cells (range 0.037–9.39) (P = .001). Patients recovering their WBC to 1,000/ml within 10 days of completing this regimen may undergo PBSC collection and achieve minimum-target cell doses of >2.5 × 10⁶ CD34+ cells/kg—100% of the time. J. Clin. Apheresis 13:1–6, 1998. © 1998 Wiley-Liss, Inc.     

CD34定量分析外周血干细胞的研究

目的定量检测外周血干细胞(PBSC).方法以藻红蛋白(PE)标记的CD34单克隆抗体,用流式细胞术(FCM)对34例白血病患者与33例健康成人外周血表达CD34抗原(CD34+)的细胞进行定量分析,并以普通光学显微镜(LM)、透射电子显微镜(TEM)、激光扫描共聚焦显微镜(LSCM)分别对CD34+/CD34-细胞进行观察.结果经LSCM证实,FCM定量检测CD34+细胞特异性强,CD34+细胞在0%～16.1%范围内线性良好(r=0.9947),当CD34+细胞为91.0%、38.3%时,CV＜3%.CD34+/CDD34-细胞在LM、TEM下形态与结构相似,但CD34+细胞在LSCM下显示圆环状橙红色荧光.结论FCM检测外周血干细胞灵敏、特异、快速,但其方法学待进一步标准化.     

Mesenchymal stem cells from CD34− human umbilical cord blood

Umbilical cord blood (UCB) is well known to be a rich source of stem cells especially for haematopoietic stem cells (HSCs). Recently, mesenchymal stem cells (MSCs) have also been shown to exist in cord blood. Although MSCs have been described by a subset of surface antigens after expansion, little is known about the cell surface phenotype of undifferentiated MSCs. The aim of this study therefore was to clarify whether undifferentiated MSCs are resident among CD34^? UCB cells. CD34⁺ cells were separated from UCB mononuclear cells (MNCs) by magnetic sorting and the CD34^? cell fractions were cultured in Dulbecco's modified Eagle's medium (DMEM) with 10% foetal calf serum (FCS) and basic‐fibroblast growth factor. Isolated CD34⁺ cells were also cultured in the same medium. Adherent fibroblast‐like cells at passage 3–4 were analyzed by fluorescence‐activated cell sorting (FACS) for MSC marker expression , and standard adipogenic, osteogenic and chondrogenic assays were used to investigate their differentiation potentials. After 4–5 weeks in culture, the cells from the CD34^? fraction became confluent with flat and fibroblast‐like morphology. These cells were positively stained for the mesenchymal cell markers CD29, CD73 and CD105. In adipogenic differentiation, the cells showed oil red O positive and expressed FABP4, adipsin and proliferation‐activated receptor γ‐2 (PPARγ2 genes) associated with adipogenesis. In osteogenic differentiation, calcium accumulation and osteocalcin were detected. The cells grown in chondrogenic conditions were positively stained for human aggrecan and expressed collagen type II and Sox‐9 genes. In contrast, cells from the CD34⁺ fraction failed to generate any cells with MSC morphology under the same culture conditions. Our results showed that UCB contained MSCs which are only resident in the CD34^? fraction. The MSCs could be induced to differentiate into at least three lineage cell types, adipocytes, osteoblasts and chondrocytes.     

The kinetics of G-CSF mobilization of CD34+ cells in healthy people

When healthy people are given granulocyte colony stimulating factor (G-CSF) for 10 days the number of CD34+ cells in the peripheral blood begins to increase on the fourth day, reaches a maximum on the sixth day and then decreases. In this study, we further define the time and variability of peak mobilization of CD34+ cells. Twenty-two healthy people were given G-CSF (7.5 or 10 μg kg^?1 day^?1) subcutaneously each morning for 5 days and peripheral blood CD34+ cell counts were analysed immediately prior to the fourth (day 4) and fifth (day 5) G-CSF injection and 24 h after the fifth injection (Day 6). White blood cell (WBC) and neutrophil counts were greatest on day 6 [WBC = 43.8 ± 13.9 × 10⁹ L^?1 (mean ± 1 SD) and neutrophils = 36.6 ± 12.8 × 10⁹ L^?1]. In contrast the CD34+ cell counts on day 6 (107 ± 104 × 10⁶ L^?1) were less than on day 5 (128 ± 136 × 10⁶ L^?1) (P= 0.048) but still greater than on day 4 (60.7 ± 40.2 × 10⁶ L^?1) (P < 0.0001). The CD34+ cell counts of 10 donors were measured 2, 4 and 6 h after the fifth injection to determine if the counts increased further between days 5 and 6. The number of CD34+ cells in the blood on day 5 2 h after the fifth injection (193 ± 277 × 10⁶ L^?1) was greater than the number prior to the injection (158 ± 190 × 10⁶ L^?1), 4 h post-injection (139 ± 158 × 10⁶ L^?1) and 6 h post-injection (170 ± 236 × 10⁶ L^?1), but the differences were not significant (P= 0.29, 0.25 and 0.45). The number of CD34+ cells in the blood of 12 people were measured before and after the fourth G-CSF dose. Prior to the day 4 injection the CD34+ count was 61 ± 40 × 10⁶ L^?1. At 2, 4 and 6 h the counts were 60 ± 40, 61 ± 29 and 64 ± 30 × 10⁶ L^?1, respectively, and the differences were not significant (P= 0.99, P= 0.98, and P= 0.73). In conclusion, when healthy volunteers are given daily G-CSF injections, the number of mobilized CD34+ cells was the greatest on day 5, slightly less on day 6 and the least on day 4. If only one PBSC component is needed, PBSCs can be collected on day 5 after only 4 days of G-CSF. If PBSC components are collected on both days 5 and 6, the fifth dose can be given either before or after the collection of the first PBSC component.     

人骨髓间充质干细胞与脐血CD34+细胞体外扩增

为了研究骨髓间充质干细胞(MSC)及细胞因子对脐血CD34 造血祖细胞体外扩增的作用,及其扩增作用 对细胞黏附分子的影响,用免疫磁珠富集脐血CD34 细胞,然后接种到含有或不含有MSC和细胞因子的24孔培 养板,体外培养1周,观察不同指标并进行组间比较。结果表明:①SDF-1α SCF TPO FL因子组合与SCF TPO FL因子组合对脐血CD34 细胞的扩增作用无显著性差异(无论有无MSC细胞层存在)(P>0.05);②MSC 与上述细胞因子共存的培养体系优于相应的单纯细胞因子培养体系(P<0.05);③扩增前与扩增后脐血造血祖 细胞黏附分子CD44的表达没有明显变化。结论:趋化因子SDF-1α对SCF TPO FL因子组合的扩增作用无显 著影响;MSC增加细胞因子的脐血细胞体外扩增的作用;体外扩增不影响跻血细胞黏附分子CD44的表达。     

移植物中CD34+细胞及T细胞亚型对HLA相合同胞异基因外周血造血干细胞移植预后的影响

目的 探讨移植物中CD34+细胞及T细胞剂量对HLA相合同胞异基因外周血造血干细胞移植(allo-PBSCT)预后的影响.方法 流式细胞术检测移植物中CD34+细胞,CD3+、CD3+CD4+及CD3+CD8+T细胞含量,按患者体重计算出移植物中单个核细胞(MNC),CD34+细胞,CD3+、CD3+CD4+及CD3+CD8+T细胞数量,根据中位数分别将患者分为高剂量组和低剂量组,比较高剂量和低剂量组患者移植后造血重建、移植物抗宿主病(GVHD)、移植相关死亡(TRM)、复发、总体生存(OS)率以及无病生存(DFS)率的发生情况.结果 CD34+细胞高剂量组(34例)移植后中性粒细胞和血小板的恢复速度显著加快(P值均<0.05).CD3+CD4+、CD3+CD8+T细胞高剂量组和相应低剂量组相比,Ⅱ-Ⅳ度aGVHD发生率有增高趋势(P值分别为0.089和0.098).CD3+CD4+及CD3+CD8+T细胞高剂量组和相应低剂量组相比,TRM显著增高(P值均<0.05);多因素分析显示,CD3+CD4+和CD3+CD8+T细胞输注剂量是患者TRM的影响因素(RR分别为13.12和25.90,P值均<0.05).各高剂量组和相应低剂量组比较复发率差异无统计学意义(P值均>0.05).CD3+ CD4+及CD3+CD8+T细胞高剂量组分别和相应低剂量组相比,OS显著降低(P值均<0.05);多因素分析显示,CD3+CD4+和CD3+CD8+T细胞输注剂量是患者OS的影响因素(RR分别为3.71和3.01,P值均<0.05);CD3+CD4+T细胞高剂量组和低剂量组相比,DFS显著降低(P值均<0.05);多因素分析显示,CD3+CD4+T细胞输注剂量(RR=6.91,P=0.011)是患者DFS的影响因素.结论 高剂量CD34+细胞移植可加快移植后造血重建;移植物中高含量的CD3+CD4+及CD3+CD8+T细胞会增加患者TRM,降低OS或DFS.     

间充质干细胞与人脐血CD34+细胞共移植对NOD/SCID小鼠造血重建的影响

目的 观察间充质干细胞(MSC)与不同比例脐血CD34+细胞共移植对NOD/SCID小鼠造血重建的影响,明确MSC与脐血CD34+细胞共移植的最适数量.方法 给60Coγ射线照射的雌性NOD/SCID小鼠共移植人MSC和不同比例的脐血CD34+细胞,观察共移植后42 d内小鼠外周血白细胞和血小板变化,并于移植后42 d处死小鼠,用流式细胞术检测外周血、骨髓和脾脏人源细胞含量.结果 与单纯脐血CD34+细胞移植相比较:①脐血CD34+细胞与1、5和10倍数量的MSC共移植时,可明显减轻外周血白细胞和皿小板的下降幅度(P<0.01),提前1周使白细胞和血小板恢复至正常水平(P<0.05),三组间差异无统计学意义(P>0.05);②MSC与不同比例的脐血CD34+细胞共移植均可明显提高外周血、骨髓和脾脏造血细胞植入率.比例为10:1时,外周血、骨髓和脾脏中的人源细胞(huCD45+细胞)含量分别增加了(2.8±0.6)倍、(3.5±0.9)倍和(5.2±0.6)倍,增加倍数差异均有统计学意义(P<0.01),达到了最佳的植入效果.结论 脐血CD34+细胞与10倍数量的MSC共移植可达到最佳的促进造血重建作用.