新型外周血CD34+细胞动员剂--抗CD49d单克隆抗体的实验研究

为了探讨外周血干细胞动员的新途径，用抗CD49d单克隆抗体和rhG-CSF及二者联合给小鼠皮下注射，动态观察小鼠外周血的白细胞总数和CD34^ 细胞数的变化，并将各种动员方法所获得的干细胞分别进行干细胞移植。结果发现，给予动员剂后小鼠的外周血白细胞总数和CD34^ 细胞比例明显升高，以rhG-CSF和抗CD49d单克隆抗体联合给药效果最佳。移植后各组小鼠均获造血重建，以联合动员组造血恢复速度最快。结论：抗CD49d单克隆抗体能有效动员小鼠外周血干细胞，与rhG-CSF具有协同作用。     

人参总皂甙协同造血生长因子体外诱导CD34+造血干/祖细胞扩增与分化的作用

为探讨人参总皂甙(total saponins of panax ginseng,TSPG)协同造血生长因子体外诱导CD34+造血干/祖细胞(HSC/HPC)扩增与分化的作用,收集人脐血、骨髓细胞并采用StemsepTM干细胞分选系统分离纯化CD34+HSC/HPC,用不同剂量TSPG加入不同组合的造血生长因子进行培养,检测细胞总数、CD34+细胞和CD33+细胞比例及集落形成细胞总数(CFC)、粒系祖细胞(CFU-GM)数量变化.结果显示10-70μg/ml TSPG均可不同程度地提高脐血细胞总数、CFC数和CD34+细胞数,50μg/ml是最佳刺激浓度,可使细胞总数、CFC数和CD34+细胞数分别增至(2470.5±79.96)×103、(53.96±4.29)×100%和(21.86±3.09)×100%;20μg/ml是液体培养诱导骨髓CD34+细胞向粒系分化的最佳浓度,可使细胞总数、CFU-GM和CD33+细胞分别增至(133.2±9.03)×103、(26.78±1.91)×100%和(16.98±1.73)×100%;甲基纤维素半固体培养检测显示,TSPG(10-50μg/ml)均能提高CD34+细胞形成CFU-GM的集落产率,以TSPG 20μg/ml效果最为明显.结论合适剂量的TSPG能够促进CD34+造血干/祖细胞体外扩增与定向诱导分化.     

不同来源CD34^＋CD38^＋和CD34^＋CD38^—细胞群造血性能的不均一…

利用ＦＡＣＳ将ＣＤ３４＾＋细胞分选为ＣＤ３４＾＋ＣＤ３８＾－两个亚群，并比较了来源于人脐带血、骨髓及外周血两个亚群的分布比例和造血性能的差异。结果有髓中ＣＤ３４＾＋及其亚群细胞所占比例最高，外周血最低；脐带血来源的亚群细胞体外形成各系造血集落及液体培养体系中维持长期造血的能力最强，外周血最弱。     

CD34+造血祖细胞的定向诱导分化研究

目的：探讨不同细胞因子组合定向诱导ＣＤ３４＋细胞向红系、粒系、巨核系及树突状细胞（ＤＣ）分化的能力。方法：利用免疫磁珠法（ＭＡＣＳ）分离纯化脐血ＣＤ３４＋细胞，在液体培养体系中经不同细胞因子组合的诱导，检测各系祖细胞及ＤＣ的扩增倍数。结果：干细胞因子、白细胞介素（ＩＬ）３、ＩＬ６、粒巨噬细胞集落刺激因子（ＧＭＣＳＦ）、粒细胞集落刺激因子、红细胞生成素、血小板生成素的不同组合，可使红系、粒系或巨核系细胞优势生长，其祖细胞可分别被扩增１４．９７±２．８９，１４．４６±３．１９及３４．６７±４．６２倍，ＣＤ４１ａ＋细胞增加了１７．２９±２．３４倍，ＦＬＴ３配基＋ＧＭＣＳＦ＋ＩＬ４＋肿瘤坏死因子α的组合可诱导ＣＤ３４＋细胞形成大量树突状细胞，ＣＤ１ａ＋细胞的比例增至２４．２８％±２．１４％（对照组为０．３６％±０．２８％）。结论：不同细胞因子组合可定向诱导ＣＤ３４＋细胞向红系、粒系、巨核系及树突状细胞分化，这在造血调控研究、造血细胞支持治疗及肿瘤免疫治疗中具有广阔的应用前景     

人胚胎CD34+细胞体外向神经细胞分化的实验研究

目的最近研究显示骨髓干细胞可向多种组织细胞分化、且在细胞移植治疗中具有显著效果.胚胎肝是胚胎中后期的主要造血组织.研究人胚胎肝白细胞抗原34阳性细胞(antigens,CD34+)是否具有向神经组织细胞分化的潜能.方法实验于2003-03/12在暨南大学中心实验室完成.采用磁性活化细胞分选磁珠分离试剂盒从自然流产3月龄活胎的肝脏分离CD34+细胞,以DMEM/F12+100 mL/L胎牛血清培养液培养、传代;第五代细胞待细胞融合达80%后,用1 mmol/L β-巯基乙醇+10-7mol/L维甲酸诱导24 h,磷酸盐缓冲液洗涤,然后在无血清培养基中继续培养.免疫细胞化学检测诱导后的细胞中神经细胞特异蛋白.结果培养的人胚胎肝CD34+细胞经β-ME+RA诱导后,细胞表现神经元样细胞形态,表达神经细胞特异蛋白.统计显示48%细胞nestin染色阳性,91%细胞NSE染色阳性,85%细胞NeuN染色阳性,80%细胞TuJ-1染色阳性,53%细胞NF-M染色阳性.结论人胎肝CD34+细胞在体外能向早期未成熟神经细胞分化;提示CD34+胎肝细胞在神经系统疾病细胞治疗和基因治疗中应用价值.     

造血干细胞移植中CD34+细胞最佳分选的应用效果评价

目的探讨联合化疗加细胞因子动员自体外周血CD34+细胞的采集及临床级磁性分选仪(CliniMACS)分选的最佳方法,评价分选后CD34+细胞在造血干细胞移植中的应用效果.方法2001-03/2002-01在南京市鼓楼医院血液科病房收治自身免疫性疾病患者9例.符合纳入标准患者9例,男3例,女6例.采用环磷酰胺[2～4 g/(m2·d)]+粒细胞集落刺激因子(G-CSF)[5～10 μg/(kg·d)]作为动员剂,CS-3000Plus血细胞分离机采集外周血单个核样细胞,CliniMACS作CD34+细胞分选,观察分选前后的细胞计数、纯度、细胞活力,流式细胞术进行细胞表型检测及粒巨细胞集落形成单位(CFU-GM)培养.计算CD34+细胞的采集得率和分选回收率.观察CD34+细胞移植后造血功能恢复的情况.结果经环磷酰胺加G-CSF动员后,采集时机多以一次采集能够获得足够数量的CD34+细胞(CliniMACS分选和冷冻保存的耗损计算在内)为原则,外周血白细胞总数＞6×109 L-1或CD34+细胞＞0.4%时开始采集,其中8例采集1次,1例采集2次.每例患者可获单个核样细胞(MNC)总数(0.924～5.360)×1010,MNC(2.6～19.5)×108/kg,CD34+细胞(2.4～37.2)×106/kg,经CliniMACS系统分选后,CD34+细胞回收率为51%～93%,平均回收率为87%,CFU-GM回收率为35%～62%.CD34+细胞纯度为94.3%～98.4%,平均96.71%.CD3+,CD19+,CD56+,CD14+细胞去除2～4个对数级.经冰冻保存后的CD34+细胞的回收率为78%～99%,CFU-GM回收率为82%～99%,实际回输CD34+细胞为(2.0～8.3)×106/kg,移植后均获造血重建.结论掌握最佳动员、采集及分选方法,CD34+细胞可获较高产率,移植后造血功能恢复较快.     

三七皂苷对人骨髓CD34+造血干/祖细胞的增殖分化作用

为了探讨三七皂苷 (PNS)对人骨髓CD34+ 造血干 /祖细胞的刺激增殖和诱导分化的作用 ,用DynalM 4 5 0CD34+ 免疫磁珠阳性选择法获取高纯度的人骨髓CD34+ 细胞 ,采用多向祖细胞 (CFU Mix)体外集落培养和流式细胞术检测细胞增殖与分化。结果显示 :经免疫磁珠阳性选择 ,从骨髓细胞收获的CD34+ 细胞获得率为 (1.0 3±0 .74 ) % ,流式细胞术分析纯度达到 86 % - 93%。PNS 10mg/L和 2 5mg/L能刺激CD34+ 细胞增殖 ,使CFU Mix集落生成增加 ,2 5mg/L的PNS对CFU Mix产率提高 (34.7± 16 .0 ) % (P <0 .0 1) ,是促进造血的最适浓度 ;PNS2 5 ,5 0和 10 0mg/L时 ,能诱导CD34+ 细胞向粒系细胞分化 ,粒系表面标记CD33+ 和CD15 + 的细胞百分比均明显高于无PNS的对照组 ,而红系细胞表面标记CD71+ 和G A+ 细胞百分比则无明显变化。结论 :PNS对CD34+ 造血干 /祖细胞不但具有显著的刺激增殖作用 ,而且能够诱导其向粒系细胞定向分化的效应     

造血干/祖细胞体外定向诱导分化为粒细胞的研究

为探讨利用人造血干/祖细胞体外定向诱导分化的人粒细胞应用于临床大剂量放，化疗后预防感染的可行性，利用源自人胎盘脐带血的CD34^ 细胞及SCF，IL-3，IL-6和G-CSF的细胞因子组合的培养条件。体外进行向粒细胞的诱导分化。结果表明，在该体系条件下可诱导分化出约1000倍数量的细胞，流式细胞仪检测诱导效率可达60%以上。且诱导分化的细胞染色体未出现异常。裸鼠致瘤实验表明该细胞不具致瘤性。细胞体外生长14-21天为高峰，33天后细胞不再增殖，且诱导分化出的细胞具有吞噬细菌的功能。结论：利用细胞工程的方法体外“生产”出的粒细胞具有应用安全性，且具备生理状态下产生的此种细胞应具备的基本功能。为其临床应用提供了基础。     

三种标记法对脐血CD34+造血干细胞绝对计数的比较分析

CD34抗原的相对分子质量为105000～120000，选择性表达于早期造血干/祖细胞、小血管内皮细胞和胚胎纤维母细胞表面，该抗原在原始造血中表达最强，随着细胸分化、其表达水平逐渐减弱直至消失，因此一直作为干/祖细胞表面的一种特征性标志而广泛应用于造血干细胞基础研究和临床。脐带血中含有丰富的造血干/祖细胞，被认为是极具潜力的继骨髓和外周血后的第3种造血干细胞来源。     

高迁移率族蛋白B1对人脐血造血干细胞增殖分化的影响

目的 观察辐射后骨髓基质细胞(MSC)高迁移率族蛋白B1(high mobility group box 1,HMGB1)的释放,研究HMGB1对人脐血造血干细胞(HSC)增殖分化的影响.方法 体外培养人骨髓MSC,利用ELISA方法 检测经12 Gy γ射线照射后培养上清中HMGB1含量的变化.HMGB1与CD34~+的人脐血HSC体外液体共培养6 d,通过流式细胞术检测CD34~+细胞分化指标(CD13、CD14、CD11c、CD41、CD71)的变化.集落形成实验观察HMGB1对HSC增殖分化的影响.结果辐射后,骨髓MSC培养上清中HMGBl含量为(4.3±0.9)ng/ml,较对照组HMGB1含量[(0.4±0.2)ng/ml]明显升高(P＜0.01).脐血CD34~+细胞表面表达HMGB1受体RAGE、TLR2和TLR4.HSC与HMGB1共培养6d后,与对照组比较,红系(CD71)和粒单系(CD13、CD14、CD11c)标记的表达明显增强,分别为CD13(18.4±3.8)%和(32.6±5.9)%、CD14(12.6±2.7)%和(25.4±4.4)%、CD11c(9.8±2.1)%和(20.3±3.9)%、CD71(26.6±4.6)%和(47.1±7.4)%,而巨核系标记CD41的表达[(1.1±0.4)%和(1.3±0.5)%]无明显变化.集落形成实验示共培养14 d后,红系集落、粒-巨噬细胞集落和总集落的生成较对照组明显增多(P＜0.05),联用抗-TLR2和抗-TLR4抗体可部分抑制这一作用.结论 辐射促进骨髓MSC释放HMGB1,胞外HMGB1可以促进HSC的增殖分化.辐射后,骨髓MSC释放的HMGB1与造血恢复或造血重建的关系值得进一步研究.     

Studies on the committed differentiation of CD34+ hematopoietic progenitor cells]

OBJECTIVE: To elucidate the capacity of different hematopoietic growth factors (HGFs) combinations for inducing CD34+ cells to proliferate and differentiate committedly to granulocytes, erythrocytes, megakaryocytes and dendritic cells (DC). METHODS: CD34+ cells were isolated from umbilical cord blood by using a high-gradient magnetic cell sorting system (MACS), and expanded with HGFs in a liquid culture system. Colony forming cells and antigen expression were studied by colony forming assays and FACS. RESULTS: Different combinations of HGFs, including SCF, IL-3, IL-6, GM-CSF, Epo and Tpo increased BFU-E, CFU-GM, CFU-MK and CD41a+ cells by 14.97 +/- 2.89 fold, 14.46 +/- 3.19 fold, 34.67 +/- 4.62 fold and 17.29 +/- 2.34 fold, respectively. Combination of HGFs allowed generation of a large number of DCs. Cultures of CD34+ cells with the combination of FLT-3 ligand + GM-CSF + IL-4 + TNF-alpha yielded 24.28% +/- 2.14% CD1a+ cells, while the control cultures did not. CONCLUSION: It is possible to induce CD34+ cells to proliferate and differentiate committedly to different lineage of hematopoietic cells and DC.     

P-Selectin coated microtube for enrichment of CD34+ hematopoietic stem and progenitor cells from human bone marrow

BACKGROUND: Enrichment and purification of hematopoietic stem and progenitor cells (HSPCs) is important in transplantation therapies for hematologic disorders and in basic stem cell research. Primitive CD34+ HSPCs have demonstrated stronger rolling adhesion on selectins than mature CD34- mononuclear cells (MNCs). We have exploited this differential rolling behavior to capture and purify HSPCs from bone marrow by perfusing MNCs through selectin-coated microtubes. METHODS: Bone marrow MNCs were perfused through the cell-capture microtubes coated with adhesion molecules. We washed the device lumen and visualized and estimated captured cells by video microscopy. Adherent cells were eluted by high shear, calcium-free buffer, and air embolism. We used immunofluorescence staining followed by flow cytometry to analyze CD34+ HSPCs. RESULTS: CD34+ HSPC purity of cells captured in adhesion molecule-coated devices was significantly higher than the fraction of CD34+ cells found in bone marrow MNCs [mean (SE) 2.5% (0.8%)]. P-selectin-coated surfaces yielded 16% to 20% CD34+ cell purity, whereas antibody-coated surfaces yielded 12% to 18%. Although CD34+ cell purity was comparable between selectin and antibody surfaces, the total number of CD34+ HSPCs captured was significantly higher in P-selectin devices (approximately 5.7 x 10(4) to 7.1 x 10(4)) than antibody devices (approximately 1.74 x 10(4) to 2.61 x 10(4)). CONCLUSIONS: P-selectin can be used in a compact flow device to capture HSPCs. Selectin-mediated capture of CD34+ HSPCs resulted in enrichment approximately 8-fold higher than the CD34+ cell population from bone marrow MNCs. This study supports the hypothesis that flow-based, adhesion molecule-mediated capture may be a viable alternative approach to the capture and purification of HSPCs.     

Retrovirus-mediated transfer of human alpha-galactosidase A gene to human CD34+ hematopoietic progenitor cells

Fabry disease, caused by a deficiency of lysosomal enzyme alpha-galactosidase A (alpha-gal A), is one of the inherited disorders potentially treatable by gene transfer to hematopoietic stem cells. In this study, a high-titer amphotropic retroviral producer cell line, MFG-alpha-gal A, was established. CD34+ cells from normal umbilical cord blood were transduced by centrifugal enhancement. The alpha-gal A activity in transduced cells increased 3.6-fold above the activity in nontransduced cells. Transduction efficiency measured by PCR for the integrated alpha-gal A cDNA in CFU-GM colonies was in the range of 42-88% (average, 63%). The expression of functional enzyme in TFI erythroleukemia was sustained for as long as cells remained in culture (84 days) and for 28 days in LTC-IC cultures of CD34+ cells. The ability of the transduced CD34+ cells to secrete the enzyme and to correct enzyme-deficient Fabry fibroblasts was assessed by cocultivation of these cells. The enzyme was secreted into the medium from transduced CD34+ cells and taken up by Fabry fibroblasts through mannose 6-phosphate receptors. These findings suggest that genetically corrected hematopoietic stem/progenitor cells can be an enzymatic source for neighboring enzyme-deficient cells, and can potentially be useful for gene therapy of Fabry disease.     

双份脐血间CD34^＋细胞与CD3^＋细胞相互作用对分化增殖能力的影响

目的双份脐血移植的植入动力学机制目前尚无定论,推测双份脐血中的淋巴细胞与优势份脐血的产生相关。本实验将双份脐血的CD34^＋细胞与CD3^＋细胞混合培养,观察CD3^＋细胞对CD34^＋细胞的增殖分化有无影响。方法建立液体和半固体培养体系,将免疫磁珠分选纯化的双份脐血间的CD34^＋细胞和CD3^＋细胞混合培养6d和14d。以流式细胞计数观测CD34^＋细胞培养后的分化指标（CD33,CD41,CD71）;计数集落形成单位（GM—CFU、BFU-E、GEMM—CFU）分析CD34^＋细胞的增殖情况。结果液体共培养后各份CD34^＋细胞表面分化指标的变化。脐血CD34^＋细胞分选富集的纯度为（98．70±0．72）％。3d实验组和对照组的各项分化指标无差异（P〉0．05）;6d的CD33、CD71实验组明显低于对照组,而CD41明显高于对照组（P〈0．05）。半固体共培养后CD34^＋细胞增殖能力的变化。实验组的红系集落形成单位（BFU—E）及粒单细胞集落形成单位（GM—CFU）数低于对照组（P〈0．05）,而混合细胞集落形成数（GEMM—CFU）高于对照组（P〈0．05）。结论将两份脐血的CD34^＋细胞和CD3^＋细胞体外混合培养对CD34^＋细胞的增殖分化能力有影响,推测双份脐血间的相互作用可部分地通过CD3^＋细胞介导。     

The removal of human breast cancer cells from hematopoietic CD34+ stem cells by dielectrophoretic field-flow-fractionation

Dielectrophoretic field-flow-fractionation (DEP-FFF) was used to purge human breast cancer MDA-435 cells from hematopoietic CD34+ stem cells. An array of interdigitated microelectrodes lining the bottom surface of a thin chamber was used to generate dielectrophoretic forces that levitated the cell mixture in a fluid flow profile. CD34+ stem cells were levitated higher, were carried faster by the fluid flow, and exited the separation chamber earlier than the cancer cells. Using on-line flow cytometry, efficient separation of the cell mixture was observed in less than 12 min, and CD34+ stem cell fractions with a purity >99.2% were obtained. The method of DEP-FFF is potentially applicable to many biomedical cell separation problems, including microfluidic-scale diagnosis and preparative-scale purification of cell subpopulations.     

大规模测序研究CD_(34)~ 造血干/祖细胞基因表达谱

目的　建立大规模测序方法 ,并用于造血干 祖细胞 (HSPC)基因表达谱的初步识别。方法　从脐血中分离CD34 细胞 ,构建cDNA文库 ,对其进行大规模表达序列标签 (EST)测序 ,用生物信息学的方法进行结果分析。结果　在获得的 986 6条EST中 ,有意义序列归并为 2 0 6 0个连续克隆 ,其中10 5 4个为已知基因 ,10 0 6个为至今尚未被公共数据库公布的新基因片段。 10 5 4个已知基因根据功能分为八个大类 :①造血相关的 73个 ;②染色体结构及细胞分裂相关的 91个 ;③细胞信号传导相关的111个 ;④细胞结构 运动相关的 48个 ;⑤细胞和机体防御相关的 41个 ;⑥基因表达 (转录、翻译及加工 )相关的 2 6 5个 ;⑦代谢相关的 192个 ;⑧未分类的 2 33个。结论　获得了HSPC表达的 10 5 4个已知基因和 10 0 6个新基因片段构成的初步基因表达谱 ,为进一步深入研究造血基因表达调控和克隆新基因奠定了基础     

培养条件对CD34~+细胞体外诱导分化和扩增红细胞的影响

目的观察培养基以及细胞接种密度对体外诱导CD34+细胞向红细胞增殖和分化的影响。方法将脐血来源的CD34+细胞用无血清培养基或含10%胎牛血清(FCS)的IMDM培养基培养(6孔培养板,3ml/孔),添加的细胞因子为100ng/ml干细胞因子(SCF)、5ng/ml白细胞介素3(IL-3)、3IU/ml促红细胞生成素(EPO),细胞初始接种密度为104/ml或105/ml,并通过间充质干细胞(MSC)的支持培养来诱导其向红系细胞扩增和分化。结果培养23d后,无血清培养基组细胞扩增倍数达到2.54×105倍,其中红系细胞>95%,而IMDM/5%FCS组的最大扩增倍数只有1.84×104倍,其中的红系细胞约占40%。培养8d后初始接种密度为104/ml的CD34+细胞增殖(420±40)倍,而105/ml的CD34+细胞增殖(162±45)倍。结论CD34+细胞在无血清培养基中的扩增倍数以及最终诱导出的红细胞,都明显高于在IMDM/10%FCS培养基中所占比例,104/ml的CD34+细胞接种密度比105/ml更有利于细胞的扩增。