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

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.

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.

The Cross-talk between ROS and p38MAPKα in the Ex Vivo Expanded Human Umbilical Cord Blood CD133^+ Cells

This study investigated the correlation between and compared the effects of reactive oxygen species（ROS） and p38 mitogen-activated protein kinase α（p38MAPKα） in the ex vivo expanded umbilical cord blood（hUCB） CD133＋ cells.hUCB CD133＋ cells were cultured in the hematopoietic stem cells（HSCs） culture medium with N-acetylcysteine（NAC,an anti-oxidant）,p38MAPKα-specific inhibitor（SB203580） or their combination.The levels of ROS and expression of phosphorylated p38MAPKα（p-p38） in CD133＋ cells were flow cytometrically detected.The efficacy of ex vivo expansion was evaluated by the density of CD133＋ cell sub-group colony-forming cells（CFC） and cobblestone area-forming cells（CAFC） assay.Our results showed decreased ROS levels in NAC,SB203580,and their combination treatment groups were almost 37%,48%,and 85%,respectively.Furthermore,SB203580 abrogated the activation of p38MAPKα more obviously than NAC.Moreover,the CD133＋ cells in SB203580 treatment group had a 21.93±1.36-fold increase,and 14.50±1.19-fold increase in NAC treatment group,but only 10.13±0.57-fold increase in control group.In addition,SB203580 treatment led a higher level increase in the number of CFU and CAFC than NAC did.These findings suggested that,in expanded CD133＋ cells,ROS activates p38MAPKα,which,in turn,induces ROS production,and p38MAPKα might be the most suitable regulator in ROS-p38MAPKα pathway for the promotion of HSCs ex vivo expansion.

Functional expression of CD95/Fas Antigen and Bcl-2 on Cord blood Hematopoietic Progenitor Cells

The cell surface expression and functional status of the CD95/Fas antigen on primitive hematopoietic progenitors isolated from human cord blood (CB) were studied. The CD34 + cells freshly isolated from CB displayed low CD95 expression. The combinations of cytokines such as SCF+FL could up regulate the expression of CD95 in vitro culture and tumor necrosis factor α (TNF α) and interon γ (IFN γ) further increased the CD95 expression induced by positive cytokines. The functional status of CD95 mediated apoptosis were analyzed by incubation of CD34 +CB cells in the presence of anti CD95 monoclonal antibodies (McAbs). The effects of anti CD95 McAbs were measured by viable cell counting, flow cytometry, LTIC and CFU C assays. A decrease of viable cells, CFU C and LTIC numbers were observed in the presence of anti CD95 McAbs and TNF α or IFN γ. However, growth factor deprivation or the early acting cytokine such as SCF and FL cross linking to CD95 caused low apoptosis of CD34 + cells. The correlation of increased intracytoplasmic levels of bcl 2 and the presence of CD95 on fresh CB CD34 + cells suggested that bcl 2 might be involved in protecting against CD95 mediated apoptosis of CB CD34 + cells.

Transplantation of microencapsulated umbilical-cord-blood-derived hepatic-like cells for treatment of hepatic failure

AIM: To investigate intraperitoneal transplantation of microencapsulated hepatic-like cells from human umbilical cord blood for treatment of hepatic failure in rats. METHODS: CD34+ cells in umbilical cord blood cells were isolated by magnetic cell sorting. In the in vitro experiment, sorted CD34+ cells were amplified and induced into hepatic-like cells by culturing with a combination of fibroblast growth factor 4 and hepatocyte growth factor. Cultures without growth factor addition served as controls. mRNA and protein levels for hepatic-like cells were analyzed by reverse transcription-polymerase chain reaction, immunohistochemistry and immunofluorescence. In the in vivo experiment, the hepatic-like cells were encapsulated and transplanted into the abdominal cavity of acute hepatic failure (AHF) rats at 48 h after D-galactosamine induction of acute hepatic failure. Transplantation with PBS and unencapsulated hepatic-like cells served as controls. The mortality rate, hepatic pathological changes and serum biochemical indexes were determined. The morphology and structure of microcapsules in the greater omentum were observed. RESULTS: Human albumin, alpha-fetoprotein and GATA-4 mRNA and albumin protein positive cells were found among cultured cells after 16 d. Albumin level in culture medium was significantly increased after culturing with growth factors in comparison with culturing without growth factor addition (P < 0.01). Compared with the unencapsulated group, the mortality rate of the encapsulated hepatic-like cell-transplanted group was significantly lower (P < 0.05). Serum biochemical parameters, alanine aminotransferase, aspartate aminotransferase and total bilirubin in the encapsulated group were significantly improvement compared with the PBS control group (P < 0.01). Pathological staining further supported these findings. At 1-2 wk post-transplantation, free microcapsules with a round clear structure and a smooth surface were observed in peritoneal lavage fluid, surviving cells inside microcapsules were found by trypan blue staining, but some fibrous tissue around microcapsules was also detected in the greater omentum of encapsulated group by hematoxylin and eosin staining. CONCLUSION: Transplantation of microencapsulated hepatic-like cells derived from umbilical cord blood cells could preliminarily alleviate the symptoms of AHF rats.

四物汤对血虚证小鼠骨髓细胞CD34抗原表达的影响

目的探讨四物汤对60 Coγ射线或环磷酰胺诱导的血虚证小鼠骨髓细胞CD 34抗原分子表达的影响。方法用60 Coγ射线全身照射小鼠或腹腔注射环磷酰胺造成小鼠血虚证模型 ,实验分正常组、模型组、小剂量组、中剂量组、大剂量组 ,荧光标记小鼠骨髓细胞并用流式细胞仪测定CD 34+ 细胞在骨髓有核细胞中的比例 ,同时做小鼠骨髓细胞集落培养。结果与结论四物汤可促进血虚小鼠骨髓中干祖细胞增生 ,增加CD 34抗原分子的表达 。

G-CSF对健康人骨髓和外周血CD_(34)^+细胞和T细胞亚群影响的动态观察

目的 :探讨G -CSF对健康人骨髓及外周血CD3 4 + 细胞和T细胞亚群的影响。方法 :对 12例健康人 ,以G -CSF15 0 μg/ 12h ,皮下注射 ,连用 6d。应用流式细胞仪测定CD3 4 + 和T细胞亚群。结果 :应用G -CSF4 8h后 ,骨髓CD3 4 + 细胞开始明显增加 ,72h后外周血CD3 4 + 细胞开始明显增加 ,96h后两者达峰值 ,均较应用前差异显著 (P <0 .0 1)。T淋巴细胞亚群变化不明显 (P>0 .0 5 )。结论 :健康人应用G -CSF后骨髓及外周血CD3 4 + 细胞逐渐增加并于 96h后达到高峰 ,T细胞亚群则无明显变化。

肿瘤患者外周血干细胞动员过程中CD_(34)^+细胞的动态变化及意义

为观察肿瘤患者 CD+ 34 细胞数量在动员过程中的动态变化 ,确定采集干 /祖细胞的最佳时机 ,采用环磷酰胺 (CTX)联合粒细胞集落刺激因子 (G- CSF)对 2 1例肿瘤患者进行造血干 /祖细胞动员。动员过程中 ,每天进行血细胞计数 ,于前期、极期、恢复早期、恢复期计数外周血 CD+ 34 细胞、白细胞 (WBC)、单核细胞 (MNC)、血小板(Plt)。结果显示 ,不同患者出现极期、恢复早期、恢复期的时间差异较大。与前期相比 ,极期 CD+ 34 明显降低(P<0 .0 5 ) ,恢复期则显著增加 (P<0 .0 1)。WBC、MNC、Plt变化均与 CD+ 34 细胞变化呈显著正相关 (r分别为 0 .99、0 .82 7、0 .886 ,P均 <0 .0 1)。提示在 WBC>5 .0× 10 9/ L时采集外周血造血干细胞 (PBSC)较合适 ,MNC>1.5×10 9/ L时采集 PBSC较理想 ,监测 Plt计数变化 。

CD_(34)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 %～ 1 6 .1 %范围内线性良好 (r =0 .9947) ,当CD34+细胞为 91 0 %、38 3%时 ,CV <3%。CD34+/CD34-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 。

人Delta-like 1蛋白的表达及其对动员外周血CD34^+细胞的扩增作用

构建pET32a(+)-hDll1DSL原核表达载体,表达、纯化hDll1DSL蛋白,观察其对动员外周血CD34+细胞的体外扩增作用。克隆hDll1DSL,构建pET32a(+)-hDll1DSL重组表达载体。转化大肠杆菌BL21,IPTG诱导蛋白表达,镍珠亲合层析纯化蛋白。RBP-j报告基因实验及Notch下游分子Hes1检测证实hDll1DSL活性。磁珠分选动员外周血CD34+细胞,加入hDll1DSL或联合SCF、FL、TPO孵育一周,观察体外扩增作用。结果表明:成功克隆hDll1DSL,并构建了pET32a(+)-hDll1DSL重组表达载体。在大肠杆菌BL21成功表达Trx-hDll1DSL融合蛋白,经镍珠亲合层析纯化蛋白,成功获得高纯度的Trx-hDll1DSL融合蛋白。配体活性实验显示,可溶性的Trx-hDll1DSL蛋白可以激活RBP-j报告基因,并且能上调Notch下游分子Hes1的表达,证明其能够激活Notch信号通路。此外,Trx-hDll1DSL融合蛋白与SCF、FL及TPO联用,具有协同刺激CD34+细胞体外扩增的作用。我们成功构建了pET32a(+)-hDll1DSL重组表达载体,表达、纯化了具有生物学活性的Trx-hDll1DSL融合蛋白,具有协同刺激CD34+细胞体外扩增的作用,为造血干/祖细胞体外扩增体系的优化研究奠定了基础。

脐血CD34+细胞的分离与纯化

脐血造血干细胞的分离是进行干细胞移植、体外扩增培养的关键。研究采用明胶自然沉降法、Ficoll分层法分离脐血MNC后,用MACS分离纯化CD34+细胞,计数并用流式细胞仪进行纯度分析。结果显示:每份脐血的采集量平均为95+52ml,3g/dl明胶自然沉降法所获MNC密度平均为(5.76±0.67)×107/ml;CD34+细胞密度平均为(5.53±1.16)×105/ml,较Fi-coll分层法高(P<0.01)。因此,3g/dl明胶自然沉降法是一种较理想的分离MNC的方法,用明胶沉降法和MACS相结合是分离脐血CD34+细胞的理想方法。

细胞因子扩增脐带血CD_(34)^+细胞中LTC-IC的变化

目的 :探讨脐带血造血干细胞的体外扩增及移植最佳时机。方法 :免疫磁珠法分离纯化脐带血 CD+ 3 4细胞 ,在细胞因子 FL T3配体、血小板生成素作用下 ,进行体外扩增 ,流式细胞仪检测培养体系中 CD+ 3 4 细胞数量的变化 ,甲基纤维素法检测 CFU - GM、长期培养起始细胞 ( L TC- IC)。结果 :经过 2周的培养 ,有核细胞扩增 ( 2 1± 5 )倍 ,CD+ 3 4 细胞扩增 ( 9± 3 )倍 ,CFU- GM扩增 ( 164± 5 1)倍 ,L TC- IC扩增 ( 6.5± 3 .1)倍 ,随着体外培养时间的延长 ,有核细胞、CD+ 3 4 细胞和 CFU- GM得到进一步扩增 ,但培养体系中已缺少 L TC- IC。结论 :FL T3配体联合血小板生成素能扩增具有造血干细胞特征的 L TC- IC细胞 ,培养时间以

以逆转病毒介导对人脐血CD_(34)^+造血细胞进行人MDR1基因转染的实验研究

探讨逆转录病毒介导的MDR1基因转导入脐血CD34+细胞的最佳方法,为MDR1基因转导的临床应用打基础。方法:用磷酸钙沉淀法将含有人全长MDR1cDNA的逆转录病毒载体pHaMDR1/A转到包装细胞PA317中,建立产病毒细胞系,以人脐血中分离的CD34+造血干/祖细胞为靶细胞,在体外进行基因转染,转导的条件为:与含病毒的上清液共培养12天,每天更换病毒上清液,上清液中加入IL-3,IL-6和SCF三种造血生长因子(HGF),转染后用集落培养法测定对COL的耐药性,用PCR检测14～17天所形成集落的MDR1cDNA,计算转染率,用免疫组化法检测P170的阳性程度,并观察不同时间间隔加HGF对脐血CD34+细胞的扩增和转染的影响。结果:脐血CD34+细胞转染阳性为86.4%,P170的阳性率为77.0%,77.1%的集落对6ng/ml的COL耐受,57.4%的集落对7ng/ml的COL耐受。结论:此转染系统既能有较好的转导效果,也有较好的扩增效果,有一定的临床实用价值。

脐血CD_(34)^+细胞免疫表型的分析

应用免疫磁珠法分离脐血CD细胞，以比较CD细胞亚群及各系相关抗原的变化。经过分离，CD细胞由1．47±0．77％升至57．39±16．17％，分离后CDCD细胞占CD细胞的比率为7．82±4．79％CD。细胞纯化同时可减少CD细胞达14．12±9．18倍，CD细胞减少16．42±21．47倍；B系（CD(19)）、巨核系（CD(41)）、NK系（CD(56)）各抗原表达率在CD细胞分离后均明显降低。结论：CD细胞纯化可明显减少CD细胞，应用纯化的CD细胞进行移植应加强支持治疗。

Caspase-3在脐血CD_(34)^+造血干/祖细胞中的表达及意义

目的 :探讨脐血CD3 4+ 干 /祖细胞在不同细胞因子支持下的体外扩增过程中Caspase 3表达及意义。方法 :采用RT PCR、Westerblot和流式细胞仪分析技术测定脐血CD3 4+ 细胞在体外扩增过程中的生物学特性及Caspase 3的表达。 结果 :Caspase 3mRNA在新鲜分离的脐血CD3 4+ 细胞中低水平表达 ,在细胞因子支持下体外培养 3d ,扩增的CD3 4+ 细胞中Caspase 3mRNA和蛋白质表达上调 ,但在该两种细胞中仅能检测到分子量为32 0 0 0的无活性酶原形式的Caspase 3,随着体外培养时间的延长 ,在IL 3、IL 6和GM CSF组合条件下 ,Caspase 3被激活 ,可检测到分子量为 2 0 0 0 0的裂解片段。结论 :虽然造血干细胞的凋亡是个复杂的过程 ,但在脐血CD3 4+干 /祖细胞体外扩增过程中 ,Caspase

应用G-CSF对不同人群外周血CD_(34)^+细胞和T细胞亚群影响的动态变化

目的 探讨重组人粒细胞集落刺激因子 (G -CSF)对健康人及处于完全缓解的恶性血液病患者的外周血CD+34细胞和T细胞亚群的影响。方法 对 12例健康人和 16例自体外周血干细胞移植患者 ,以G -CSF 15 0 μg 12h ,皮下注射 ,连用 6d。应用流式细胞仪测定外周血CD+34 和T细胞亚群。结果 (1)应用G -CSF前 ,两者的外周血CD+34细胞分别为 (0 .39± 0 .2 7) %和 (0 .4 7± 0 .2 5 ) % ,两者之间无明显差异 (P >0 .0 5 )。应用 72h后 ,CD+34 细胞分别达(1.2 9± 0 .6 4 ) %和 (1.4 7± 0 .95 ) % ,较前均有明显增加 (P <0 .0 1) ,两者之间无明显差异 (P >0 .0 5 )。应用 96h后 ,CD+ 34 细胞达高峰 ,分别为 (1.4 1± 0 .73) %和 (1.5 8± 0 .83) % ,两者之间无明显差异 (P >0 .0 5 ) ,但较应用G -CSF前差异显著 (P <0 .0 1)。 (2 )无论是否应用G -CSF ,恶性血液病患者的T细胞亚群比例均处于倒置状态 ,而健康人T细胞亚群则比例正常。随两者应用G -CSF后CD+34 细胞逐渐增加 ,T细胞亚群变化不明显。结论 健康人及处于完全缓解的恶性血液病患者 ,在应用G -CSF后 ,外周血CD+ 34 细胞比例逐渐增加并于 96h后达到高峰 ,T细胞亚群无明显变化。