脐血CD34^＋细胞体外扩增脐血巨核祖细胞的研究

本研究探讨人脐血CD34^＋细胞体外扩增的巨核祖细胞的生物学特性及其免疫原性变化，为体外扩增脐血巨核祖细胞的临床应用提供实验依据。采用Ficoll-Hapaque分离法分离人脐血单个核细胞，应用免疫磁珠法（MACS）再分离富集CD34^＋细胞，在含血小板生成素（TPO，50ng／ml）、白介素-1]（IL—11，50ng／ml）和肝素（25U／ml）的无血清液体培养体系中培养14天。用流式细胞术检测扩增产物免疫表型（CD34^＋、CD41a^＋、CD61^＋、CD34^＋CD41a^＋及CD34^＋CD61^＋）、巨核细胞凋亡率及其表面HLA Ⅰ、Ⅱ类分子的表达，并进行巨核细胞集落形成单位（CFU—Mk）的检测。结果显示：脐血CD34^＋细胞能够有效地向巨核细胞分化，CD41a^＋和CD61^＋细胞比例在培养第14天达到峰值，CD34^＋CD41^＋和CD34^＋CD61^＋细胞比例在扩增第7天达到最高峰[分别为（3．41±2．80）％和（1．89±1．43）％]；CFU—Mk大集落在扩增第7天达到高峰（（20．66±32．79）倍]，小集落在扩增第10天达到高峰[（435．62±482．65）倍]；在培养7、10和14天时巨核细胞的凋亡率分别为（19．48±9．64）％、（26．87±9．03）％和（52．46±11．74）％，其中培养7天和10天的凋亡率无显著性差异（P〉0．05），培养14天的凋亡率显著高于7天和10天（P均〈0．05）；巨核细胞表面HLA Ⅰ、Ⅱ类分子的表达随着扩增天数的延长逐渐降低，其中培养0到10天阶段下降明显．结论：采用TPO＋IL 11＋肝素组合．可以有效地扩增脐血巨核祖细胞；培养7天，CFU—Mk大集落扩增倍数、CD34^＋CD41^＋和CD34^＋CD61^＋细胞比例均达高峰，这是巨核祖细胞体外扩增的较佳培养时间。     

脐血CD133^＋细胞体外扩增巨核系祖细胞的研究

本研究探讨脐血CD133^＋（UCB—CD133^＋）细胞体外扩增巨核系祖细胞的能力和最佳收获时间。采用免疫磁珠激活细胞分选系统（MACS）分选UCB—CD133^＋细胞，将纯化的UCB—CD133^＋细胞接种于含TPO、IL-3和SCF的无血清液体培养体系中体外扩增巨核系祖细胞，在培养第7、10和14天进行细胞计数，流式细胞仪检测扩增过程中CD133、CD34、CD41抗原表达的动态变化，并采用半固体法对不同扩增阶段的细胞进行巨核祖细胞集落形成单位（CFU—MK）培养。结果表明：培养至第7天时，UCB—CD133^＋细胞扩增效果最佳，扩增了8、2-1-2．2倍；培养至第14天，细胞总数扩增了116倍；培养至10天时，平均1个CD133^＋细胞所产生的CD133^＋CD41^＋和CD34^＋CD41^＋细胞数最多，分剐为2．5±0．9和2．6±0.5个，所产生的CD41^＋细胞为20．3±5、9个；扩增前后的UCB—CD133^＋细胞均能形成CFU—MK，扩增第10天的UCB—CD133^＋细胞所形成的CFU—MK总数最多，CFU—MK扩增倍数为59．5±11．8倍。巨核细胞免疫组织化学染色显示，扩增后的巨核系细胞多呈幼稚状态，未见血小板形成。结论：UCB—CD133^＋细胞具有较强的体外扩增巨核系祖细胞的能力，培养第10天扩增效能最佳。     

抗TGF-β1单克隆抗体对脐血CD34^＋细胞体外扩增作用的研究

为了探讨TGF—β1单克隆抗体对脐血CD34^＋细胞的扩增作用,本研究将分离纯化的脐血CD34＋细胞分为3组：①空白对照组：当天分选的新鲜脐血CD34＋细胞;②对照组：含SCF、FLT3-L、IL-3、IL-6四种因子组合的无血清液体培养体系中培养3天的脐血CD34＋细胞;③实验组：条件同对照组,但加入了TGF—β1单克隆抗体。3组均检测单个核细胞（MNC）计数,流式细胞术检测CD34和c—kit,计数混合集落（CFU—GEMM）、红系爆式集落（BFU—E）、粒系集落（CFU—GM）。结果显示：实验组MNC、CD34＋细胞、CD34＋c—kit＋细胞计数分别为[（2．35±0．25）×10^5、（1．16±0．29）×10^5、（1．09±0．26）×10^5],明显高于对照组[（1．25±0．13）×10^5、（0．55±0．19）×10^5、（0．51±0．2）×10^5],（P均〈0．01）。实验组CD34＋c—kit -亚群计数为（12．95±3．17）×10^3,明显高于对照组（1．71±0．83）×10^3,二者相比有显著性差异（P〈0．01）。实验组中早期集落CFU—GEMM、BFU—E的产率[（16．3±4．72）×10^3,（65．0±20．96）×10^3]明显高于对照组[（5．0±2．58）×10^3,（16．25±7．93）×10^3]（P〈0．01）,相对较晚期集落CFU—GM的产率在对照纽[（4．0±2．28）×10^3]和实验组[（6．33±2.85）×10^3]均高于空白组[（0．75±0．29）×10^3],但在对照组和实验组之间无显著性差异（P〉0．05）。此结果表明,TGF—β1单克隆抗体促进了脐血MNC和CD34＋细胞的扩增,且早期细胞CD34＋c—kit -细胞扩增更为突出;提高了早期集落CFU—GEMM和BFU—E的产量,而对相对较晚期的髓系集落CFU—GM的产量无明显影响。结论：TGF—β1单克隆抗体能协同其它生长因子有效扩增脐血CD34＋细胞,并保留一定量更早期的造血祖细胞,减轻了造血祖细胞分化的压力。     

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。     

不同细胞因子组合对人脐血单个核细胞体外扩增及CD49d和CXCR4表达的影响

为了探讨不同的细胞因子组合对脐血单个核细胞体外的扩增作用及扩增后CD49d和CXCR4的变化，将新鲜脐血标本分离的单个核细胞接种于含有不同细胞因子组合的无血清无基质培养体系中培养7天，在0天，7天检测有核细胞数，CD34^＋细胞数及CD34^＋CXCR4^＋，CD34^＋CD49d^＋的细胞数和集落形成单位（CFU）数．根据不同细胞因子组合实验分组为：对照组；SF组（SCF＋FL）；SFT组（SCF＋FL＋TPO）和SFT6组（SCF＋FL＋TP0＋IL-6）。结果表明，和对照组相比，SF组合仅能低水平支持脐血造血细胞扩增，加入TPO后即SCF／FL／TPO组合能有效的扩增脐血细胞，但SFT和SFT6两组之间差异却无明显发生（P〉0．05）；SF，SFT和SFT63组的细胞因子组合均可提高脐血CD34^＋细胞CD49d，CXCR4的表达，但3组之间差异无显著性（P〉0．05）。结论：SF组合可协同扩增人造血细胞，但协同作用较弱；TPO在脐血造血干／祖细胞体外扩增中起重要调节作用，而IL-6作用不显著；SCF／FL／TPO 3种因子组合不仅可促进脐血造血祖细胞的扩增，而且可上调脐血造血细胞CD49d，CXCR4表达。     

不同剂量TPO对小鼠骨髓MSC增殖的影响

为了探讨不同剂量血小板生成素（TPO）对小鼠骨髓间充质干细胞（MSC）增殖的影响，将20只昆明小鼠（35±5g）随机分为低、中、高3个剂量实验组与对照组：给实验组分别腹腔注射TPO25、50和100μg／kg，而给对照组腹腔注射生理盐水0．1ml／g，每日1次，连用5日：每组分别于最后1次注射后12小时收集小鼠骨髓，计数骨髓有核细胞数（BMNC），以10^6／cm^2接种、培养并计数原代成纤维样细胞集落形成单位（CFU—F），同时对其进行成骨、成脂肪诱导分化，用流式细胞术检测BMNC中CD90^＋、CD105^＋、CD34^＋细胞比例并鉴定CFU—F的表型。结果显示：与对照组相比，实验组所获得的BMNC、CD90^＋、CD105^＋、CD34^＋细胞比例和CFU—F集落数明显增加（P〈0．05）。3个剂量中以50μg/kgTPO组增加最明显，但50μg/kg组的CFU—F集落数与100μg/kgTPO组的CFU—F集落数相比，差异无统计学意义（P〉0．05）。CFU—F样MSC具有成骨、成脂肪分化的能力。结论：TPO促进BMNC数、CD90^＋、CD105^＋细胞数和CFU—F集落数增多，即促进骨髓MSC的增殖，但是TPO促进骨髓MSC增殖的作用不随剂号的增加而增加．     

间充质干细胞对脐血CD34^＋细胞扩增及其细胞特性变化的影响

本研究探讨脐带间充质干细胞（MSC）对CD34^＋细胞（HSPC）体外扩增的支持作用及对CD34^＋细胞表面标志、归巢黏附分子、集落形成能力等干细胞特征变化的影响。用免疫磁珠法从新鲜分离的脐血单个核细胞分离CD34^＋造血干祖细胞（HSPC）；用MSC饲养层（feeder）制备经^137Cs照射的间充质干细胞饲养细胞（MSC feeder cells）。将CD34^＋细胞接种在不同的培养体系中，实验分为3组：HSPC＋CK组为培养液中加入细胞因子组合（SCF、FL和TPO），HSPC＋MSC组为CD34^＋细胞接种在MSC feeder上，HSPC＋MSC＋CK组同时加入细胞因子组合及MSC饲养细胞。培养后4、7、10、14天计数有核细胞总数（MNC），计算细胞扩增情况；用流式细胞术检测不同处理组间CD34^＋细胞及亚群免疫表型、归巢黏附分子和集落形成能力。结果表明：在2周的培养时间里，3组MNC和CD34^＋细胞均明显增加，MNC扩增数依次HSPC＋MSC＋CK组〉HSPC＋CK组〉HSPC＋MSC组。体外扩增10天内HSPC＋MSC＋CK组MNC得到大量的扩增，同时CD34^＋细胞的扩增亦较高。培养4天3组细胞CD34^＋比例较0天有明显下降（P〈0．01）；扩增后CD34^＋细胞比例：HSPC＋MSC组〉HSPC＋MSC＋CK组〉HSPC＋CK组（P〈0．01）；各组CD34^＋细胞亚型细胞比例有所不同，HSPC＋CK组4天时CD34^＋CD38^-细胞有一过性升高（62．71％），之后迅速降低，7天时为0．05％；HSPC＋MSC组7天时CD34^＋CD38^-细胞比例为18．92％，与HSPC＋CK组比较差异有统计学意义（P〈0．05）。从集落形成分析结果看出：MSC、细胞因子混合组扩增后细胞集落形成能力在不同时间点均维持在较高水平。结论：脐血CD34^＋细胞在体外短期培养（〈7天）下，MSC和细胞因子联合应用能同时使CD34^＋细胞得到明显的扩增并维持造血干祖细胞的生物学特征。     

Notch配体δ-1对IL-6/sIL-6R融合蛋白诱导红系祖细胞分化成熟的影响

目的 探讨Notch配体δ-1在红系造血细胞分化过程中对可溶性IL-6受体（sIL-6R）生物效应的影响。方法 用CD34免疫磁珠和FACS Vantage流式细胞仪筛选脐血单个核细胞中的CD34^＋CD38^-细胞；将CD34^＋CD38^-细胞用含SCF、Flt3L、TPO和IL-3四种生长因子组合（4GFs）的培养基培养7d，然后用CD36免疫磁珠分离CD36^＋红系祖细胞，用流式细胞术检测IL-6R和血型糖蛋白（GPA）的表达，并分选CD36^＋GPA—IL-6R^＋和CD36^＋GPA—IL-6R^-细胞，将这两种表型的细胞分别进行集落分析；将CD36^＋GPA—IL-6R^-细胞用含有4GFs、4GFs＋IL-6或4GFs＋IL-6／sIL-6R融合蛋白（FP6）培养基并在加与不加Notch配体δ-1的情况下培养14d，并对CD36^＋GPA^high成熟红细胞进行计数。结果 CD36^＋GPA^＋细胞中IL-6R^-细胞占95％；CD36^＋GPA^-细胞可分为IL-6R^＋和IL-6R^-两部分，分别占46％和54％；IL-6R^＋细胞形成的粒-单核细胞集落形成单位（CFU—GM）数为2．1±1．8，IL-6R^-细胞形成的红系祖细胞爆式集落形成单位（BFU—E）数为58．2±18．1，明显高于IL-6R^＋细胞形成的CFU—GM数（P〈0．05）；在含有FP6的培养体系中，CD36^＋GPA^high细胞计数为（1．400±0．180）×10^6；在含FP6和Notch配体δ-1的培养体系中，CD36^＋GPA^high细胞计数为（2．460±0．190）×10^6，明显高于单独含有FP6的培养体系（P〈0．05）。结论 Notch配体δ-1可增强IL-6-红系细胞分化过程中sIL-6R所介导的生物学效应。     

基质细胞衍生因子-1和血小板第4因子对体外扩增后脐血CD34+细胞黏附特性和趋化功能的影响

为了研究基质细胞衍生因子-1（SDF—1）和血小板第4因子（PF4）对扩增后脐血CD34^＋细胞归巢相关功能的影响，将纯化的脐血CD34^＋细胞接种入无血清培养液中，加入不同组合的细胞因子FST（FL＋SCF＋TPO）、FST＋SDF—1、FST＋PF4或FST＋SDF—1＋PF4，分别于培养第7、10、14天检测CD34^＋细胞扩增倍数、集落形成能力、细胞的黏附分子表达、总黏附性、趋化功能。结果表明：①加入SDF—1的实验组CD34^＋细胞及造血祖细胞集落扩增倍数高于对照组；②加入SDF—1明显上调扩增的CD34^＋细胞CD49e的表达，加入PF4明显上调扩增的CD34^＋细胞CD49e、CD54的表达，在扩增体系中加入SDF—1或PF4均能够明显提高扩增的CD34^＋细胞的总黏附性；③在扩增体系中加入SDF—1能够明显提高扩增的CD34^＋细胞的自发迁移率，但导致CXCR-4的表达和SDF—1诱导迁移率降低；而PF4能够明显提高扩增的CD34^＋细胞的CXCR-4的表达和SDF—1诱导迁移率；在扩增体系中同时加入SDF—1和PF4能够明显提高扩增的CD34^＋细胞自发迁移率和SDF—1诱导迁移率。结论：体外扩增体系中加入SDF—1和PF4能够上调部分归巢相关黏附分子的表达，保持扩增的CD34^＋细胞的黏附和迁移能力，有利于降低体外扩增对造血干／祖细胞（HSPC）归巢相关功能的不利影响，维持扩增的HSPC的归巢潜能。     

动员人外周血巨核祖细胞体外扩增的研究

本研究探讨多种细胞因子(TPO、SCF、FL、IL-1、IL-3、IL-6)组合的几种培养体系对人外周血CD34+细胞体外诱导扩增生成巨核细胞的作用,研究人外周血来源的巨核细胞体外扩增的最佳细胞因子组合及培养时间。用Ficoll-Hapaque分离法分离动员的外周血(MPB)单个核细胞,免疫磁珠法分离纯化CD34+细胞,并将其在含胎牛血清的液体培养体系中、各组细胞因子诱导下培养15天。在不同时间点采用血细胞计数板进行细胞计数,采用流式细胞术检测培养体系中CD41+细胞的含量;同时采用甲基纤维素半固体培养法进行巨核细胞集落培养,测定巨核细胞集落形成单位(CFU-MK)的数量。结果表明经过15天的培养,在MPB来源的CD34+细胞体外诱导并扩增巨核祖细胞体系中,以TPO/FL/IL-6/IL-3组合的扩增效果最好,明显高于其它3组,CD41+细胞第5天、10天分别扩增了93.97±17.27倍、131.23±18.26倍。第15天CD41+细胞含量及CD41+细胞数迅速下降。CFU-MK产率(/1×103个细胞)第5天、10天分别为83.33±10.02个、120.67±13.01个,明显高于其余3组。结论以TPO/FL/IL-6/IL-3因子组合为体外诱导扩增巨核祖细胞的最佳组合,动员外周血的巨核祖细胞体外诱导扩增以培养第10天为宜。本实验建立了动员人外周血来源的巨核祖细胞体外扩增体系。     

CFU-Mk content of immunoselected CD34+ peripheral blood progenitor cells, evaluated with an adapted serum-free methylcellulose assay, is predictive of platelet lineage reconstitution in children with solid tumors

Immunoselected CD34+ peripheral blood progenitor cell (PBPC) transplantation is now frequently used to support autologous hematopoiesis after myeloablative therapy, its feasability having been proved by several groups. However, we and others observed delayed platelet recovery. We hypothesized that immunoselection processing might induce selective loss of megakaryocyte progenitors, or a decrease in their proliferation. We used a colony-forming units megakaryocyte (CFU-Mk) assay to evaluate these consequences and predict platelet recovery in patients. In CD34+ PBPCs from 10 children with solid tumors, we observed no selective loss in CFU-Mk numbers during immunoselection processing and no impairment of clonogenicity. The CFU-Mk yield (59.2 +/- 11.3%) was at least similar to the CD34+ yield (44.2 +/- 3.8%). We assessed the predictive value of CFU-Mk numbers infused for recovery of platelet lineage. We found an inverse correlation between the time taken to reach a platelet count greater than 50 x 10(9)/L and only the CFU-Mk dose (r = -0.71; p = 0.022) among the different type of progenitors, including colony-forming units granulocyte-macrophage (CFU-GM), burst-forming units erythrocyte (BFU-E) and colony-forming units-mixed (CFU-Mix). These findings suggest that CFU-Mk number could be used as sole predictive functional parameter for platelet reconstitution in children after immunoselection of CD34+ cells, in particular for low CD34+ cell dose, and thus as an indicator for initial quality of hematopoietic cells before in vitro expansion.     

体外扩增的脐血单个核细胞植入NOD/SCID小鼠的研究

为了探讨在无血清、无基质培养条件下SCF、FL和TPO 3种因子组合体外扩增的脐血单个核细胞(MNC)的最佳移植时机及植入潜能,将SCF,FL和TPO 3种因子组合体外扩增的脐血单个核细胞培养14天,在0、7、10和14天检测有核细胞数(TNC),CD34 细胞数,CD34 CXCR4 细胞数,CD34 CD49d 的细胞数及集落形成单位(CFU)数,并将SCF FL TPO 3种因子组合的无血清无基质条件下扩增培养7天前后的脐血单个核细胞移植给经亚致死量照射的NOD/SCID小鼠,6周后用流式细胞术,PCR法检测存活小鼠体内的人源性细胞.结果表明,经过14天的培养,脐血细胞得到了有效的扩增,TNC数,CD34 细胞数,CD34 CD49d 的细胞数于7天达高峰,其后开始下降,而CFU数,CD34 CXCR4 细胞数于第10天达高峰.在移植6周后,扩增脐血移植组的NOD/SCID小鼠的存活率和人源性CD45 细胞的检出率分别为56.25%和(1.39±0.63)%,高于新鲜脐血移植组31.25%和(0.73±0.16)%,亦高于生理盐水移植组(0和0),差异有显著性(p＜0.05),扩增脐血移植组有6只NOD/SCID小鼠骨髓细胞中可检测到人特异ALU序列的表达.结论体外培养7-10天可能是收获细胞的最佳时机;SCF FL TPO 3种因子组合扩增7天的脐血单个核细胞能够植入NOD/SCID小鼠,其植入水平优于未扩增的脐血;上调脐血造血细胞上CXCR4,CD49d的表达可能会增加脐血造血细胞的植入能力.     

Ex vivo expansion of CD34+ umbilical cord blood cells in a defined serum-free medium (QBSF-60) with early effect cytokines

To investigate the clinically applicable conditions that support substantial expansion of both primitive and more mature hematopoietic cells of umbilical cord blood (UCB) for transplantation in adults, enriched CD34+ cells from 8 fresh UCB samples and 4 expanded UCB products were cultured in defined serum-free medium (QBSF-60) in the presence of a cytokine combination of SCF, Flt-3-ligand (FL), thrombopoietin (TPO), IL-3 for up to 2 weeks. Fresh medium with cytokines was supplemented or exchanged at day 4, day 7, and day 10. The proliferative response was assessed at day 7, day 10, and day 14 by evaluating the following parameters: nucleated cell (NC), clonogenic progenitors (colony-forming unit-granulocyte-macrophage [CFU-GM], burst-forming unit-erythrocyte [BFU-E], CFU-GEMM, and high-proliferative potential colony-forming cell [HPP-CFC]), immunophenotypes (CD34+ cells and CD34+ subpopulations), and LTCIC. Simultaneously numerical expansion of various stem/progenitor cells, including primitive CD34+CD38-HLA-DR- subpopulation and LTCIC, CD34+ cells, and clonogenic progenitors to mature nucleated cells, were continuously observed during the culture. An average 103.32 +/- 71.37 x 10(6) CD34+ cells (range 10.12 x 10(6)-317.9 x 10(6)) could be obtained from initial 1.72 +/- 1.13 x 10(6) UCB CD34+ cells after 10-14 days cultured under the described conditions. Sufficient CD34+ cells (>50.0 x 10(6)) for transplantation in adults would be available in all but one UCB collections after 10-14 days expansion. The expanded CD34+ cells sustained most of the in vitro characteristics of initial unmanipulated CD34+ cells, including clonogenic efficiency (of both primitive and committed progenitors), the proportion of CD34+CD38-HLA-DR- subpopulation, and the expansion potential. Initial addition of IL-3 to the cocktail of SCF + FL + TPO had positive effects on the expansion of both primitive and, especially, the more mature hematopoietic cells. It accelerated the expansion speed and shortened the optimal culture time from 14 days to 10 days. These results indicated that our proposed short-term culture system, consisting of QBSF-60 serum-free medium with a simple early acting cytokine combination of SCF + FL + TPO, could substantially support simultaneous expansion of various stem/progenitor cell populations involved in the different phases of engraftment. It would be a clinically applicable protocol for ex vivo expansion of CD34+ UCB cells.     

脐血CD34+细胞及红系祖细胞扩增的实验研究

脐血是造血祖细胞的丰富来源之一,选择合适的培养条件,体外诱导其定向扩增为红系祖细胞,输入体内产生成熟红细胞。本实验旨在探讨脐血单个核细胞(MNC)体外红系定向扩增的理想因子组合(Flt3配基FL联合TPO、SCF、EPO及FL、SCF、TPO)对CD34 细胞扩增的影响。将单个核细胞接种至stemspan无血清培养液中,共分3组:A组为对照组,B组为TPO SCF FL EPO IGF1组,C组为TPO SCF FL组,C组在第6天及以后换液加入EPO和IGF1。于培养0、6、10、14天进行细胞计数,细胞集落测定,流式细胞术测定细胞的CD34、CD34CD71、CD71GPA细胞的比例。结果表明:经10天培养后,B组总细胞数扩增6.89倍,而C组3.06倍;B组CD34 细胞增加4.83,而C组2.47倍;B组集落形成细胞数增加4.3倍,而C组增加2.5倍;B组红系祖细胞BFUE和CFUE数增加5.4倍,而C组3.1倍;B组CD34 CD71 细胞数增加8.72倍,而C组3.37倍;B组CD71 GPA 细胞数增加53.4倍,而C组30.29倍。结论:脐血MNC在无血清培养液中加入FL SCF TPO实现了CD34 细胞及集落形成细胞的扩增。脐血MNC在无血清培养液中加入FL SCF TPO EPO IGF1短期液体培养获得红系祖细胞的扩增,在第0天比6天加入EPO获得更多红祖细胞(P<0.05)。由于TPO SCF FL EPO IGF1组的集落形成细胞数、CFUE和BFUE数于第10天最多,故培养后收获时     

GM-CSF对脐血CD34+巨核祖细胞体外扩增及分化的影响

本实验旨在研究GM-CSF对脐血CD34^＋细胞诱导分化为巨核细胞的影响.采用免疫磁珠法分选CD34^＋细胞,在含有TPO＋IL-3＋SCF并添加了不同浓度（5、20、100ng/ml）的GM-CSF的无血清培养基中进行培养.培养6、10、14天后计数单个核细胞（MNC）,检测CD41^＋细胞比例和CFU-MK.结果表明,培养14天后3种不同浓度GM-CSF对MNC均有明显的扩增作用,其中以20和100ng/ml GM-CSF的扩增效果较好.3种不同浓度的GM-CSF均使CD41^＋细胞比例增加,20和100ng/ml与5 ng/ml GM-CSF相比更能提高CD41^＋细胞的比例.5和20 ng/ml的GM-CSF能促进CFU-MK的形成,但100ng/ml的GM-CSF却抑制CFU-MK的形成.结论：在TPO＋IL-3＋SCF细胞因子组合中添加GM-CSF有利于促进脐血CD34^＋细胞诱导分化为巨核细胞.     

Reinjection of ex vivo-expanded primate bone marrow mononuclear cells strongly reduces radiation-induced aplasia

To assess the therapeutic efficacy of ex vivo-expanded hematopoietic cells in the treatment of radiation-induced pancytopenia, we have set up a non-human primate model. Two ex vivo expansion protocols for bone marrow mononuclear cells (BMMNC) were studied. The first consisted of a 7-day culture in the presence of stem cell factor (SCF), Flt3-ligand, thrombopoietin (TPO), interleukin-3 (IL-3), and IL-6, which induced preferentially the expansion of immature hematopoietic cells [3.1 +/- 1.4, 10.0 +/- 5.1, 2.2 +/- 1.9, and 1.0 +/- 0.3-fold expansion for mononuclear cells (MNC), colony-forming units-granulocyte-macrophage (CFU-GM), burst-forming units erythroid (BFU-E), and long-term culture initiating cells (LTC-IC) respectively]. The second was with the same cytokine combination supplemented with granulocyte colony-stimulating factor (G-CSF) with an increased duration of culture up to 14 days and induced mainly the production of mature hematopoietic cells (17.2 +/- 11.7-fold expansion for MNC and no detectable BFU-E and LTC-IC), although expansion of CFU-GM (13.7 +/- 18.8-fold) and CD34+ cells (5.2 +/- 1.4-fold) was also observed. Results showed the presence of mesenchymal stem cells and cells from the lymphoid and the megakaryocytic lineages in 7-day expanded BMMNC. To test the ability of ex vivo-expanded cells to sustain hematopoietic recovery after radiation-induced aplasia, non-human primates were irradiated at a supralethal dose of 8 Gy and received the product of either 7-day (24 h after irradiation) or 14-day (8 days after irradiation) expanded BMMNC. Results showed that the 7-day ex vivo-expanded BMMNC shortened the period and the severity of pancytopenia and improved hematopoietic recovery, while the 14 day ex vivo-expanded BMMNC mainly produced a transfusion-like effect during 8 days, followed by hematopoietic recovery. These results suggest that ex vivo expanded BMMNC during 7 days may be highly efficient in the treatment of radiation-induced aplasia.     

Thrombopoietin is synergistic with other cytokines for expansion of cord blood progenitor cells

We investigated the effects of recombinant human thrombopoietin (TPO) in combination with various cytokines including erythropoietin (EPO), interleukin-3 (IL-3), interleukin-6 (IL-6), and stem cell factor (SCF) on megakaryopoiesis, and the expansion of CD34+CD41a+ cells from human cord blood CD34+ cells with these cytokines under serum-free conditions. Human cord blood CD34+ cells were cultured in Megacult (Stem Cell Technologies Inc. Vancouver, Canada) in the presence of recombinant growth factors. Colony-forming unit-megakaryocyte (CFU-M) colonies were counted on day 14. CD34+CD41a+ and CD34-CD41a+ cell expansion was analyzed using a serum-free liquid culture system for 7 days with recombinant growth factors. TPO alone had a concentration-dependent effect on megakaryocyte colony growth. At concentrations above 1 ng/ml, TPO supported significant CFU-Meg colony formation in a concentration-dependent manner. The combination of TPO plus other cytokines, including EPO, IL-3, and SCF, resulted in a synergistic enhancement of the number of CFU-Meg colonies, but IL-6 failed to enhance the effect of TPO. The number of CD41a+ cells increased after 7 days in liquid culture of human cord blood CD34+ cells with various cytokines (EPO, IL-3, IL-6, SCF) combined with TPO, but SCF plus TPO only resulted in a significant synergistic increment of CD34+CD41a+ cells compared with TPO alone. The results of the present study indicate that EPO, IL-3, and SCF can be synergistic with TPO to stimulate proliferation of CFU-Meg and suggest that SCF plus TPO can expand CD34+CD41a+ cells to effect the rapid recovery of platelets in patients following stem cell transplantation.