Expression of Caspase－3 in Cord Blood CD34^＋ Cells during Culture in vitro

Objective: To investigate the expression and significance of caspase-3 protein in CD34^+ cells from cord blood (CB) during culture in vitro with different growth factors. Methods: RT-PCR, Western blot and flow cytometry techniques were used to detect the expression of caspase-3 in CD34^+ CB cells during culture in vitro. Results: Caspase-3 mRNA was constitutively expressed at a low level in freshly isolated CD34^+ cells. The expression of caspase-3 mRNA and protein was upregulated when these cellswere first expanded in suspension culture with growth factors for 3 days. However, only the 32 kDa inactive caspase-3 proenzyme was detected in the freshly isolated CD34^+ cells as well as during the first 3 days expansion with cytokines. With longer culture time in vitro, especially in the presence of the combination of IL-3, IL-6 and GM-CSF, caspase-3 was activated and a cleavage product of 20 kDa became detectable.Conclusion: Caspase-3 is involved in apoptosis of primitive CB CD34^+ cells during expansion in vitro.

CD34^(+)细胞数对单倍体造血干细胞移植治疗恶性血液病的影响

背景:单倍体造血干细胞移植与较高的植入功能不良相关,因此经常要求更高的CD34^(+)细胞数量,但现有研究关于异基因造血干细胞移植CD34+细胞剂量和研究终点关系的结论是有争议的。目的:探究CD34^(+)细胞数对单倍体造血干细胞移植治疗恶性血液疾病临床结果的影响。方法:纳入2019年1月至2021年12月期间于郑州大学第一附属医院造血干细胞移植中心行单倍体造血干细胞移植的恶性血液病患者,总计135例。结合既往研究结果及移植中心经验,以CD34+细胞数5.0×10^(6)/kg为截止点,将队列分为2组。评估两组的移植物植入情况、复发率及非复发死亡率、总生存期和无进展生存期等相关临床指标。结果与结论:①CD34+细胞剂量与血小板的植入相关,高剂量组血小板的植入时间早于低剂量组(14 d vs.16 d,P=0.013)。②两组患者3年总生存期无显著差异(67.5%vs.53.8%,P=0.257);两组间的无进展生存期也无显著性差异(65.6%vs.44.2%,P=0.106),但根据疾病风险指数(DRI)进行分层分析后发现低危患者高剂量组的3年无进展生存期较低剂量组升高(72.0%vs.49.3%,P=0.036)。③高剂量组3年累积复发率小于低剂量组(16.0%vs.33.5%,P=0.05)。④两组100 d内非复发死亡率高剂量组大于低剂量组,但无显著差异(17.3%vs.6.7%,P=0.070);进行分层分析发现,高危患者中高剂量组100 d内非复发死亡率明显高于低剂量组(20.0%vs.3.3%,P=0.046)。⑤综上所述,输注>5.0×10^(6)/kg的CD34^(+)细胞可促进血小板早期植入,可改善移植中低危风险患者的3年无进展生存期,并且降低移植后累积复发率;但在高危患者中,高剂量CD34+细胞导致移植后100 d内的非复发死亡率增高,考虑可能与移植后早期重度急性移植物抗宿主病的发生增多相关,因此考虑对回输高剂量CD34+细胞的患者应加强移植物抗宿主病的监测。

CD19^(+)CD24^(+)CD27^(+)调节性B细胞及IL-10、IL-34与系统性红斑狼疮中医证型的关系

目的:探讨CD19^(+)CD24^(+)CD27^(+)调节性B细胞(Bregs细胞)及白细胞介素(IL)-10、IL-34与系统性红斑狼疮(SLE)中医证型的关系。方法:选取2022年4月~2024年4月在本院接受治疗的117例SLE患者为研究组,并纳入同期进行体检的86名健康体检者为对照组,检测对比两组的CD19^(+)CD24^(+)CD27^(+)Bregs细胞中CD24^(high) CD27^(+)比例、CD24^(mid) CD27^(+)比例以及血清IL-10、IL-34水平。另将研究组根据中医辨证分型分为热毒炽盛证、肝肾阴虚证、脾肾阳虚证,检测对比不同中医证型患者间CD24^(high) CD27^(+)比例、CD24^(mid) CD27^(+)比例、IL-10、IL-34、肾功能及系统性红斑狼疮疾病活动指数(SLEDAI)的差异。结果:研究组的CD24^(high) CD27^(+)比例、CD24^(mid) CD27^(+)比例、IL-10、IL-34水平均高于对照组,差异有统计学意义(P<0.05)。117例SLE患者中热毒炽盛证有49例、肝肾阴虚证33例、脾肾阳虚证35例。CD24^(high) CD27^(+)比例、CD24^(mid) CD27^(+)比例、IL-10、IL-34水平及SLEDAI评分均在肝肾阴虚证、脾肾阳虚证、热毒炽盛证中依次上升,差异有统计学意义(P<0.05);脾肾阳虚证患者的血清肌酐、尿素氮、24h尿蛋白定量均高于热毒炽盛证及肝肾阴虚证患者(P<0.05)。结论:SLE患者血清CD19^(+)CD24^(+)CD27^(+)Bregs细胞、IL-10、IL-34水平均与中医证型有关,可作为中医辨证论治的辅助指标。

外周血CD4^(+)PD-1^(+)Tcells及CD4^(+)T淋巴细胞ATP含量与复发性卵巢癌疗效的相关性分析

目的 探讨外周血CD4^(+)程序性细胞死亡受体-1(PD-1)^(+)T cells及CD4^(+)T淋巴细胞三磷酸腺苷(ATP)含量与复发性卵巢癌疗效的相关性。方法 选取30例复发性卵巢癌患者为复发组,30例未复发卵巢癌患者为非复发组;另选取30名同期体检健康者作为对照组。评估外周血CD4^(+)PD-1^(+)T cells及CD4^(+)T淋巴细胞ATP含量与复发性卵巢癌疗效的相关性。结果 复发组和非复发组的CD4^(+)PD-1^(+)T cells较对照组明显升高(P<0.05)。复发组和非复发组的CD4^(+)T淋巴细胞ATP含量较对照组明显降低(P<0.05)。复发组治疗后CD4^(+)PD-1^(+)Tcells显著低于治疗前(P<0.05),治疗后CD4^(+)T淋巴细胞ATP含量显著高于治疗前(P<0.05)。CD4^(+)PD-1^(+)T cells与复发性卵巢癌疗效成负相关(r=-0.393,P=0.039),CD4^(+)T淋巴细胞ATP含量与复发性卵巢癌疗效成正相关(r=0.449,P=0.031)。结论 复发性卵巢癌患者外周血CD4^(+)PD-1^(+)T cells及CD4^(+)T淋巴细胞ATP含量与疗效密切相关。

慢性阻塞性肺疾病患者血清VEGF水平、外周血CD34^(+)细胞数量与骨骼肌功能障碍的关系

目的检测慢性阻塞性肺疾病(COPD)患者血清血管内皮生长因子(VEGF)水平、外周血CD34^(+)细胞数量,并分析二者与骨骼肌功能障碍的关系。方法选取北京市门头沟区医院2021年7月至2022年12月收治的96例COPD患者,依据COPD患者骨骼肌功能障碍诊断标准将患者分为骨骼肌功能障碍组52例和无骨骼肌功能障碍组44例;选择同期在医院体检的健康者96例为对照组。测定所有受试者肺功能指标[用力肺活量(FVC)、第一秒用力呼气容积占预计值的百分比(FEV1%)、第一秒用力呼气容积/用力肺活量(FEV1/FVC)],骨骼肌功能[握力、4m步速、5次起坐试验时间、6min步行距离(6MWD)],血清C-反应蛋白(CRP)、白细胞计数(WBC)水平;酶联免疫吸附法、流式细胞仪分别检测血清VEGF水平、CD34^(+)细胞数量;分析COPD患者血清VEGF、CD34^(+)细胞数量、骨骼肌功能的相关性,COPD患者发生骨骼肌功能障碍的影响因素,血清VEGF、CD34^(+)细胞数量预测COPD患者发生骨骼肌功能障碍的价值。结果与对照组相比,无骨骼肌功能障碍组FVC、FEV1%、FEV1/FVC、握力、4m步速、6MWD降低(P<0.05),5次起坐试验时间较长、CRP、WBC水平升高(P<0.05),骨骼肌功能障碍组BMI、FVC、FEV1%、FEV1/FVC、握力、4m步速、6MWD降低(P<0.05),5次起坐试验时间较长、CRP、WBC水平升高(P<0.05);与无骨骼肌功能障碍组相比,骨骼肌功能障碍组BMI、握力、4m步速、6MWD降低(P<0.05),5次起坐试验时间较长(P<0.05)。对照组、无骨骼肌功能障碍组、骨骼肌功能障碍组血清VEGF水平依次升高,CD34^(+)细胞数量依次降低(P<0.05)。COPD患者血清VEGF水平与CD34^(+)细胞数量呈负相关(P<0.05);血清VEGF水平与握力、4m步速、6MWD呈负相关(P<0.05),与5次起坐试验时间呈正相关(P<0.05);CD34^(+)细胞数量与握力、4m步速、6MWD呈正相关(P<0.05),与5次起坐试验时间呈负相关(P<0.05)。BMI低水平、VEGF高水平、CD34^(+)细胞数量低水平是COPD患者发生骨骼肌功能障碍的危险因素(P<0.05)。血清VEGF、CD34^(+)细胞数量、两者联合预测COPD患者发生骨骼肌功能障碍的曲线下面积分别为0.900、0.835、0.935。结论COPD患者血清VEGF水平明显增加,外周血CD34^(+)细胞数量明显下降,二者水平变化与骨骼肌功能障碍的发生具有相关性。

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

PERIPHERAL BLOOD CD34^+ CELL MOBILIZATION IN 42 PATIENTS WITH SEVERE AUTOIMMUNE DISEASE

Objective To evaluate the feasibility and safety of peripheral CD34+ cell mobilization in patients with severe autoimmune disease. Methods Forty-two patients underwent a total of 46 mobilizations by the regimen of cyclophosphamide 2-3 g/m2 +recombinant human granulocyte colony stimulating factor (rhG-CSF) 5 μg·kg-1·d-1. The positive selection of CD34+ cell was performed through the CliniMACS. Results In 8.1±2.3 days after administration of cyclophosphamide, the peripheral white blood cell and mononuclear cell (MNC) decreased to the lowest level. In 3.7±1.6 days after injection of rhG-CSF, the peripheral absolute MNC and CD34+ cell counts were 0.95×109/L and 0.035×109/L, respectively. After 2.4±0.6 times of leukapheresis, there gained 4.46×108/kg of MNC and 5.26×106/kg of CD34+, respectively. After mobilization, the underlying diseases were ameliorated more or less. In systemic lupus erythematosus (SLE) patients, SLE Disease Activity Index (SLEDAI) decreased from a median of 17 to 3 (P<0.01). In rheumatic arthritis patients, an American College of Rheumatology criteria for 20%(ACR20) response was achieved in all five patients. Totally, 17.4% of patients whose absolute neutrophil count <0.5×109/L suffered infection, and 31.0% of patients had bone pain after the injection of rhG-CSF. Two patients suffered severe complications, one with acute renal failure and recovered by hemodialysis, the other died of thrombotic thrombocytopenic purpura. Failed mobilization occurred in three patients. Conclusions Sufficient CD34+ cells can be mobilized by low dose of cyclophosphamide and rhG-CSF. CD34+ cell mobilization for treatment of severe autoimmune disease not only is appropriate in both effectiveness and safety but ameliorates disease also.

妊娠及围产因素对子代脐带血CD34^(+)造血干细胞的影响分析

目的分析妊娠及围产因素对子代CD34^(+)造血干细胞数量和脐带血有核细胞总数的影响。方法选择乌鲁木齐市妇幼保健院2021年5月至2022年5月收集的120例健康产妇的新生儿脐带血标本,其中男性60例,女性60例;新生儿体质量2500~4000 g。采用XE-2100全自动血液分析仪对子代脐带血中的有核细胞进行计数。采用流式细胞分析仪分析CD34^(+)造血干细胞。收集新生儿及相应产妇的临床资料,主要包括孕母年龄、孕母血型、孕母身体质量指数(BMI)、孕母过敏史、妊娠期糖尿病、妊娠期高血压、分娩方式、产次、孕周、新生儿性别、新生儿体质量、胎盘质量、是否胎膜早破、是否羊水污染、是否脐带绕颈等信息,分析其对脐带血CD34^(+)造血干细胞影响。结果妊娠期因素主要有孕母年龄、孕母血型、孕母BMI、孕母过敏史、妊娠期糖尿病、妊娠期高血压、分娩方式、产次和孕周。围产期因素主要包括新生儿性别、新生儿体质量、胎盘质量、胎膜早破、羊水污染、脐带绕颈。根据临床信息分组进行组间比较发现,孕母血型、孕母BMI、孕母过敏史、妊娠期糖尿病、妊娠期高血压、分娩方式、产次、新生儿性别、新生儿体质量、胎盘质量、是否胎膜早破、是否羊水污染、是否脐带绕颈等因素与脐带血有核细胞总数和CD34^(+)造血干细胞数量无相关性(P>0.05),而孕母年龄和孕周均与CD34^(+)造血干细胞数量呈正相关(P<0.05)。结论子代脐带血中CD34^(+)造血干细胞数量与孕母年龄和孕周密切相关,孕母的年龄越大或孕周越大则CD34^(+)造血干细胞数量越多,这为脐血库筛选脐带血入库时提供了更多的理论依据。

Peripheral CD4^(+)CD8^(+) double positive T cells:A potential marker to evaluate renal impairment susceptibility during systemic lupus erythematosus

Lupus nephritis(LN) has a high incidence in systemic lupus erythematosus(SLE) patients, but there is a lack of sensitive predictive markers. The purpose of the study was to investigate the association between the CD4^(+)CD8^(+)double positive T(DPT) lymphocytes and LN. The study included patients with SLE without renal impairment(SLE-NRI), LN, nephritic syndrome(NS), or nephritis. Peripheral blood lymphocyte subsets were analyzed by flow cytometry. Biochemical measurements were performed with peripheral blood in accordance with the recommendations proposed by the National Center for Clinical Laboratories. The proportions of DPT cells in the LN group were significantly higher than that in the SLE-NRI group(t=4.012, P<0.001), NS group(t=3.240,P=0.001), and nephritis group(t=2.57, P=0.011). In the LN group, the risk of renal impairment increased significantly in a DPT cells proportion-dependent manner. The risk of LN was 5.136 times(95% confidence interval, 2.115–12.473) higher in cases with a high proportion of DPT cells than those whose proportion of DPT cells within the normal range. These findings indicated that the proportion of DPT cells could be a potential marker to evaluate LN susceptibility, and the interference of NS and nephritis could be effectively excluded when assessing the risk of renal impairment during SLE with DPT cell proportion.

CD34和S100共表达的ALK重排皮肤梭形细胞肿瘤2例及文献复习

目的报道2例具有独特形态学特征、CD34和S100共表达的间变性淋巴瘤激酶(ALK)重排皮肤梭形细胞肿瘤,以提高临床医师对该类软组织梭形细胞肿瘤的认识。方法收集2例外院会诊的病例,采用免疫组化EnVision二步法检测肿瘤中vimentin、ALK(D5F3)、BCL2、CD34及Ki-67的表达情况。1例使用荧光原位杂交(FISH)法断裂探针、1例通过二代测序(NGS)检测ALK基因重排。结果形态学上,肿瘤细胞由温和的梭形细胞或卵圆形细胞构成,呈束状或漩涡状排列,间质玻璃样变及黏液变性,可见较多开放的血管腔。该类肿瘤同时表达CD34和S100,存在ALK基因重排。结论2例CD34和S100共表达的ALK重排皮肤梭形细胞肿瘤具有独特的形态学,具有相同的免疫组化表达及分子特征,与NTRK重排梭形细胞肿瘤具有相似的临床病理学特征。

监测外周血CD34^(+)细胞计数预测普乐沙福联合G-CSF自体干细胞动员的效果

目的探讨外周血CD34阳性(CD34^(+))细胞计数对普乐沙福自体干细胞动员效果的预测价值。方法回顾性分析2021年5月—2023年7月中山大学附属第七医院使用人粒细胞集落刺激因子(G-CSF)联合普乐沙福进行自体干细胞动员的13例患者临床资料,分析普乐沙福动员前后外周血CD34^(+)细胞计数的变化及干细胞采集情况。结果共有13例患者纳入研究,包括淋巴瘤10例和多发性骨髓瘤3例。多发性骨髓瘤患者中1例为新诊断,另2例为复发患者;淋巴瘤患者中3例为套细胞淋巴瘤,6例为弥漫大B细胞淋巴瘤(包括1例复发),1例为B细胞淋巴瘤(不能明确类型)。本研究纳入的患者均使用G-CSF动员,在使用普乐沙福后CD34^(+)细胞计数均升高,使用普乐沙福前中位CD34^(+)细胞计数为13.3(2.5~76.1)/μL,使用普乐沙福后中位CD34^(+)细胞计数为73.6(10.4~208.70)/μL,升高4.18(1.99~13.60)倍。13例患者中有2例患者在使用普乐沙福前外周血CD34^(+)细胞计数<5/μL,均动员失败。Spearman相关分析结果显示,使用普乐沙福后CD34^(+)细胞计数与使用普乐沙福前CD34^(+)细胞数呈正相关(rs=0.769,P=0.003)。多元线性回归分析显示,使用普乐沙福后CD34^(+)细胞计数能较好地预测采集结果(P=0.004)。结论监测外周血CD34^(+)细胞计数可预测普乐沙福自体干细胞动员效果,使用普乐沙福后CD34^(+)细胞计数越多,CD34^(+)细胞采集量越大。

Repetitive administration of cultured human CD34+cells improve adenine-induced kidney injury in mice

BACKGROUND There is no established treatment to impede the progression or restore kidney function in human chronic kidney disease(CKD).AIM To examine the efficacy of cultured human CD34+cells with enhanced proliferating potential in kidney injury in mice.METHODS Human umbilical cord blood(UCB)-derived CD34+cells were incubated for one week in vasculogenic conditioning medium.Vasculogenic culture significantly increased the number of CD34+cells and their ability to form endothelial progenitor cell colony-forming units.Adenineinduced tubulointerstitial injury of the kidney was induced in immunodeficient non-obese diabetic/severe combined immunodeficiency mice,and cultured human UCB-CD34+cells were administered at a dose of 1×106/mouse on days 7,14,and 21 after the start of adenine diet.RESULTS Repetitive administration of cultured UCB-CD34+cells significantly improved the time-course of kidney dysfunction in the cell therapy group compared with that in the control group.Both interstitial fibrosis and tubular damage were significantly reduced in the cell therapy group compared with those in the control group(P<0.01).Microvasculature integrity was significantly preserved(P<0.01)and macrophage infiltration into kidney tissue was dramatically decreased in the cell therapy group compared with those in the control group(P<0.001).CONCLUSION Early intervention using human cultured CD34+cells significantly improved the progression of tubulointerstitial kidney injury.Repetitive administration of cultured human UCB-CD34+cells significantly improved tubulointerstitial damage in adenine-induced kidney injury in mice via vasculoprotective and anti-inflammatory effects.

Autologous mobilized peripheral blood CD34^+ cell infusion in non-viral decompensated liver cirrhosis

AIM: To study the effect of mobilized peripheral blood autologous CD34 positive(CD34+) cell infusion in patients with non-viral decompensated cirrhosis.METHODS: Cirrhotic patients of non-viral etiology were divided into 2 groups based on their willingness to be listed for deceased donor liver transplant(DDLT)(control, n = 23) or to receive autologous CD34+ cell infusion through the hepatic artery(study group, n= 22). Patients in the study group were admitted to hospital and received granulocyte colony stimulating factor injections 520 μg/d for 3 consecutive days to mobilize CD34+ cells from the bone marrow. On day 4,leukapheresis was done and CD34+ cells were isolated using CliniMAC magnetic cell sorter. The isolated CD34+ cells were infused into the hepatic artery under radiological guidance. The patients were discharged within 48 h. The control group received standard of care treatment for liver cirrhosis and were worked up for DDLT as per protocol of the institute. Both groups were followed up every week for 4 wk and then every month for 3 mo.RESULTS: In the control and the study group, the cause of cirrhosis was cryptogenic in 18(78.2%) and16(72.72%) and alcohol related in 5(21.7%) and6(27.27%), respectively. The mean day 3 cell count(cells/μL) was 27.00 ± 20.43 with a viability of 81.84± 11.99%. and purity of 80%-90%. Primary end point analysis revealed that at 4 wk, the mean serum albumin in the study group increased significantly(2.83± 0.36 vs 2.43 ± 0.42, P = 0.001) when compared with controls. This improvement in albumin was,however, not sustained at 3 mo. However, at the end of3 mo there was a statistically significant improvement in serum creatinine in the study group(0.96 ± 0.33 vs 1.42 ± 0.70, P = 0.01) which translated into a significant improvement in the Model for End-Stage Liver Disease score(15.75 ± 5.13 vs 19.94 ± 6.68,P = 0.04). On statistical analysis of secondary end points, the transplant free survival at the end of 1 mo and 3 mo did not show any significant difference(P =0.60) when compared to the control group. There was no improvement in aspartate transaminase, alanine transaminase, and bilirubin at any point in the study population. There was no mortality benefit in the study group. The procedure was safe with no procedural or treatment related complications.CONCLUSION: Autologous CD 34+ cell infusion is safe and effectively improves liver function in the short term and may serve as a bridge to liver transplantation.

Autologous CD34^+ and CD133^+ stem cells transplantation in patients with end stage liver disease

AIM:To assess the utility of an autologous CD34 + and CD133 + stem cells infusion as a possible therapeutic modality in patients with end-stage liver diseases.METHODS:One hundred and forty patients with endstage liver diseases were randomized into two groups.Group 1,comprising 90 patients,received granulocyte colony stimulating factor for five days followed by autologous CD34 + and CD133 + stem cell infusion in the portal vein.Group 2,comprising 50 patients,received regular liver treatment only and served as a control group.RESULTS:Near normalization of liver enzymes and improvement in synthetic function were observed in 54.5% of the group 1 patients;13.6% of the patients showed stable states in the infused group.None of the patients in the control group showed improvement.No adverse effects were noted.CONCLUSION:Our data showed that a CD34 + and CD133 + stem cells infusion can be used as supportive treatment for end-stage liver disease with satisfactory tolerability.

HUMAN PRIMITIVE HEMATOPOIETIC PROGENITOR CELLS ARE MORE ENRICHED IN CD34^+CD38^- POPULATION THAN IN CD34^+CD38^+ POPULATION

To clarify the hematopoietic potential of various sub-classes of human hematopoietic progenitor cells, we used a multicolor staining protocol in conjunction with anti-CD34 and -CD38 McAb. We characterized two cell fractions in CD34+cells with or without CD38 expression. A clonogenic assay showed that most CFC were present in CD34+CD38+ population. Morphologic analysis showed that blast-like cells were more enriched in the CD34+CD38 fraction. To clarify the biologic differences between both fractions, we examined the more primitive progenitor cell function by assessing long-term culture-initiating cells (LTC-IC) on the stromal cells. At the first two weeks, more CF.C harvested from the culture in the fractions initiated with both populations. However, more LTC-IC were present during weeks 4 to 12 in the CD34+CD38- population. These results indicate the primitive progenitors are more enriched in CD34+CD38 population than in CD34+CD38+ cells.

In vitro study of the influence of GST-π gene transfer on drug-resistance of human cord blood CD34^+ cells

Objective:To investigate the influence of GST-π gene transfer on drug-resistance of human cord blood CD34 + cells.Methods:CD34 + cells were purified from cord blood from normal full-term pregnancy.Gene transduction into human cord blood CD34 + cells was carried out using GST-π gene containing retrovirus vector.The GST-π gene expression in transduced CD34 + cell was confirmed by RT-PCR.After confirmation of GST-π gene transfer,the transfected CD34 + cells were cultured by colony assay in the presence of carboplatin.Results:GST-π mRNA was detected in 30% of CFU-GM derived from GST-π gene transduced CD34 + cells.In vitro drug resistance test showed that the number of CFU-GM formed was significantly higher (2～3 fold) in GST-π gene transduced CD34 + cells than untransduced CD34 +cells.Conclusion:GST-π gene transfer can confer resistance to hematopoietic progenitors against carboplatin in vitro.

Apoptosis of Leukemia Cells Induced by CD34^+ Cells Transferred Exogenous Fas Ligand

To assess the value of CD34 + cells transferred exogenous Fas ligand (FasL) in inducing apoptosis of human leukemic cells, the CD34 + cells transfected with F asL or without, pretreated with mitomycin C, was mixed with leukemic cell line U937 cells in presence or absence of daunorubicin (DNR) or cytosine arabinoside (Ara C). After l8 h, apoptosis of cells was detected by FCM and TUNEL. Induced for l8 h by CD34 + cells transfected with FasL or without, the ratio of apoptos is of U937 cells was (5.0±1.3) %, (10.8±0.6) % ( P < 0.01), respectively. Induced by FasL +CD34 ++DNR, FasL +CD34 ++Ara C, the ratio was (13.4±1.0) % ( P < 0.05), (17.9±1.3)% ( P <0.01), respectively. The result demonstrated that CD34 + cells transfected with exogenous FasL could induce apoptosis of human leukemic cells and showed a cytotoxic synergistic effect when used in combination with chemotherapeutic drugs, suggesting that it was possible to develop a new method in treatment of leukemia.

Effect of Homoharringtonine on Bone Morrow CD34^+CD7^+ Cells in Chronic Granulocytic Leukemia

Objective： To explore the effect of homoharringtonine （HHT） on bone morrow CD34^＋CD7^＋ cells in chronic granulocytic leukemia （CGL）. Methods： The changes of bone morrow CD34^＋CD7^＋ cells were observed after the treatment of HHT in 23 cases with CGL. The proliferation and apoptosis of CD34^＋CD7^＋ cells treated with HHT in vitro were studied. Results： The proportion of CD34^＋CD7^＋ cells in CGL （0.145±0.021） was higher than that of normal control （0.052±0.013）. The proportion of CD34^＋CD7^＋ cells in patients who got cytogenetic responses to HHT （0.072±0.020） decreased remarkably, but not in those patients who did not got cytogenetic responses to HHT, （0.137±0.023）. the proliferation of CD34^＋ cells was inhibited and the proportion of CD34^＋CD7^＋ cells decreased after cultured with HHT （0.134 in 24 h, 0.126 in 48 h and 0.102 in 72）. The apoptosis rate of CD34^＋CD7^＋ cells was higher than that in CD34^＋CDT cells （35.39%±4.39% versus 24.57%±4.01%, P〈0.05） 72 h after culture with HHT. Conclusion： The proportion of CD34^＋CD7^＋ cells in CGL was higher than that of normal control and HHT may inhibit the proliferation and induce apoptosis of bone marrow CD34^＋CD7^＋ cells.

Isolation and Characterization of Human CD34^+ Hematopoietic Progenitor Cells by High-gradient Magnetic Cell Sorting

Using a high-gradient magnetic cell sorting (MACS) system, CD34^+ cells were isolated from human bone marrow, cord blood, peripheral blood, and cultured in CFU system. The results showed that the excellent recovery (75%) and highest purity (95-99%) were acquired by using the MACS separation system, and the most CFCs were present in CD34^+ population, but not in CD34 fraction by clonogenic assays. The isolation of pure hematopoietic stem cells and progenitor cells is of experimental and clinical importance.