两步法从CD34+造血干细胞诱导树突状细胞

目的：研究如何从有限的造血干细胞获得大量的树突状细胞（DC），为进一步研究树突状细胞的生化特性及临床应用提供技术支持。方法：利用免疫磁珠法（MACS）富集CD34^ 细胞，先在培养体系中加入FLT3配体（FL）、血小板生成素（TPO）及干细胞因子（SCF）等细胞因子，然后对富集的细胞进行扩增，扩增后的细胞在GM－CSF和IL－4的作用下诱导7d，诱导后的细胞用流式细胞仪分析树突状细胞特征性表面标记CD1a。结果：两步法能够获得大量的DC，在第一步中用TPO／FL／SCF／IL－3／IL－6来扩增CD34^ 细胞能获得最多的DC。在相同的培养时间下（3周），两步法能扩增出274倍的DC，大大的超过了直接诱导的扩增倍数（24倍）。并且，随着培养时间的增长，DC的扩增倍数不断上升。结论：两步法能从少量的脐血CD34^ 前体细胞诱导扩增出大量的DC，为从病人动员的CD34^ 细胞诱导扩增DC用于临床提供了实验依据。     

增强定向造血分化信号提高人胚胎干细胞向自然杀伤细胞生成的效率北大核心CSCD

目的 探讨在造血分化阶段增强定向造血(DH)信号对人胚胎干细胞(hESCs)分化形成的自然杀伤(NK)细胞(也称为hESC-NK细胞)生成效率和功能的影响。方法 hESC(H1)经离心法形成拟胚体，在诱导造血分化的第0至8天，对照组加入BMP4、VEGF、bFGF、SCF等细胞因子；而增强定向造血(DH)组在对照组的基础上添加WNT激动剂(CHIR99021)和Nodalactivin抑制剂(SB431542)；进而采用一致的方法分化形成NK细胞。使用流式细胞术和靶细胞K562共培养等方法分析造血分化效率、NK细胞生成效率、体外效应功能及表面受体等相关分子表达。结果 相较于对照组，DH组在造血分化阶段第8天动脉生血内皮细胞(CD34+DLL4+)数量显著增加，原始造血相关细胞(CD34-CD43+)显著降低(P <0.05)。在NK细胞分化第28天分析发现，DH组NK细胞(CD45+CD56+)数量显著增加，效应功能相关分子IFN-γ、Granzyme B、Perforin、CD107a虽微弱上升，但无统计学差异，激活性受体CD16a和CD69明显增加，但NKP46显著降低，抑制性受体NKG2A显著增加，CD96显著降低(P <0.05)。结论 在hESC向造血分化过程中增强定向造血信号，在不影响NK细胞体外功能的情况下显著提高NK细胞生成效率和CD16a表达，为提高hESC-NK细胞或iPSC-NK细胞生成效率提供了一种新的思路。     

rhTPO对巨核系的定向分化效应

目的 :探讨重组人促血小板生成素 (rhTPO)对外周造血干细胞中巨核系祖细胞的定向诱导分化能力。方法 :经化疗及G CSF动员后分离的外周造血干细胞 ,进行液体和集落培养 ,研究rhTPO单独及与IL 3、IL 6、SCF的协同作用。结果 :液体培养后 ,TPO组单个核细胞数 (MNC)扩增了 ( 1.73± 0 .49)倍 ,IL 3 IL 6 SCF组MNC比种植时增加 ( 4.2 0± 1.14)倍 ,IL 3 IL 6 SCF TPO组MNC增加了 ( 4.5 3± 1.2 7)倍。单独应用TPO及TPO与IL 3、IL 6、SCF合用产生高比例的CD41a 细胞 ,TPO组培养前CD41a 细胞为 11.70 %± 5 .2 3% ,培养后CD41a 细胞为 19.17%± 6 .2 6 % ( P <0 .0 5 )。CD41a 细胞数在TPO组扩增了 ( 3.5 2± 1.18)倍 ,IL 3 IL 6 SCF组扩增了 ( 5 .32± 1.79)倍 ,IL 3 IL 6 SCF TPO组扩增了 ( 6 .94± 2 .19)倍。结论 :TPO可以定向诱导巨核系细胞的分化 ,IL 3、IL 6、SCF可以协同TPO的作用 ,这在造血调控研究 ,体外定向扩增外周血干细胞 ,促进外周造血干细胞移植患者血小板的恢复具有应用前景     

自体外周血造血干细胞移植后造血重建中CD226分子在NK细胞上表达的变化

本文应用双重免疫荧光染色和流式细胞术分析,观察自体外周血造血干细胞移植患者造血重建中,CD226分子在CD56bright和CD56dimNK细胞亚群表达的变化.结果显示,在自体外周血造血干细胞移植造血重建中,于干细胞回输第12天,CD56 NK细胞占外周血淋巴细胞百分率为26.6%,其中CD56bright亚群,占CD56 NK细胞87.3%;CD56 CD226 细胞占CD56 NK细胞92.1%,CD56brightCD226 细胞占CD56 CD226 细胞89.9%.在自体外周血造血干细胞移植造血重建中,CD56bright亚群是NK细胞造血重建最早出现并占优势的一个亚群, CD226分子可能作为一种分化标记主要表达在CD56bright亚群上.     

干细胞因子的研究及其应用

人干细胞因子（hSCF)是新近发现的重要造血细胞因子，它是酪氨酸激酶受体c-Kit的配体。SCF主要作用于早期造血干细胞、原始造血祖细胞，并且诱导这些细胞的存活、增殖和分化。SCF单独使用生物学作用低，但它与其它细胞因子具有强的协同作用。在临床I、Ⅱ和Ⅲ期研究中，SCF和G－CSF联合应用，与单独使用G－CSF比较，CD34^ 细胞数增加2－3倍。安进公司采用基因重组技术在大肠杆菌中生产的重组人SCF（r-met hSCF)商品名为STEMGENTM。SCF临床使用，包括体内干细胞扩增治疗（ex vivo)和用于基因治疗的体外培养造血干细胞。SCF与G－CSF联合使用刺激扩增外周血干／祖细胞（PBPC），可用于干／祖细胞移植，以增加患者所需PBPC的比例，减少收集PBPC的次数。本综述主要介绍了人SCF的功能，临床研究和其它潜在应用。     

脐血体外同时扩增造血干祖细胞、T细胞及树突状细胞

目的：探索体外同时扩增脐血中造血干祖细胞、T细胞及树突状细胞的可能性和最佳细胞因子组合方案。方法：采集健康正常足月产新生儿脐血，分离出单个核细胞，在不同的细胞因子组合作用下培养14天。培养于0、3、7和14天时收集细胞，用FCM分析扩增前后脐血CD34^＋、CD3^＋T及DCs细胞含量。结果：3组不同细胞因子组合实验组A：SCF＋IL-3，6；B：SCF＋IL-3，6，4；c：SCF＋IL-3，6，4（5X）均能显著扩增脐血中的单个核细胞和CD34’细胞，各组的CD34^＋细胞最高值出现在第7天，CD34^＋细胞平均增加倍数10—20倍不等。在扩增初期，各组CD3^＋T有所下降，7天时CD3^＋T细胞有不同程度的增加，14天时扩增最高的组别中CD3^＋T细胞是新鲜脐血的2倍。DCs标志CD1a、CDS0、CD83和CD86。在所有组别中培养3天时有所下降，第7天时在含IL4的组别中有显著上升，且CD1a和CD80表达高于CD83和CD86；14天时则有所回落。IL4对CD34^＋和CD3^＋T细胞扩增有一定促进作用。结论：脐血中T细胞、DC细胞在一定细胞因子组合下。可与CD34^＋细胞同时在体外被扩增和诱导分化。     

人外周血NK细胞亚群、表型和生物学特征

目的：探讨人外周血NK细胞的异质性和生物学特征。方法：利用多种标记抗体进行细胞表面和细胞内细胞毒效应分子染色，再利用流式细胞仪在单个细胞水平上分析NK细胞亚群的多样性和生物学特征。结果：NK细胞可分为CD56^ 、CD56^ ’CD16^ 和CD16^ 三个亚群。所有CD56^ NK细胞均表达CD95，但表达水平的高(CD95^bright)和低(CD95^dim)不同。在CD95^bright和CD8^ 细胞亚群中有43．5％的细胞同时表达颗粒酶B和穿孔素。而CD56^ CD16^ 和CD16^ 细胞表达CD95均为CD95^bright，同时表达颗粒酶B(83．6％)和穿孔素(89．8％)。结论：NK细胞乃异质性群体，随着CD56表达减少和CD16表达增加。其生物效应功能逐渐成熟。     

CD226在NK细胞亚群上表达规律与功能关系的研究

目的：观察CD226分子在NK细胞亚群上的分布和其他NK细胞活化性受体和抑制性受体的共存规律，及与NK细胞功能的关系。方法：分别以IL-2或IL-15刺激PBMC和MLC细胞为模型，采用双重免疫荧光染色和流式细胞术分析，观察CD226分子在CD56^bright和CD56^dim NK细胞亚群上的表达，及与NK细胞活化性受体CD16和抑制性受体NKG2A的共存关系，同时用ELISA方法检测培养上清中IFN-γ的水平。用4小时^51Cr释放试实验检测NK细胞杀伤水平。结果：在PBMC中，CD226主要分布于CD56^dim亚群，在IL-2作用下，CD226主要分布于CD56^bright,亚群，而在IL-15作用下，NKG2A^ CD226^ 双阳性细胞明显增加。在MLC活化的NK细胞中，CD226主要分布于CD56^dim亚群，在IL-15作用下，CD226主要分布于CD56^bright亚群，IL-2和IL-15都能促进CD16^ CD226^ 和NKG2A^ CD226^ 双阳性细胞的增殖。IL-2和IL-15能明显提高PBMC培养上清中IFN-γ的水平，并能促进PBMC和MLC中NK细胞的杀伤活性。结论：CD226主要分布于活化NK细胞CD56^bright群上，其表达水平及与CD16及NKG2A共存关系可能受不同细胞因子调节并与NK细胞功能相关。     

转FL基因基质细胞对脐血造血干细胞的作用

造血干细胞不足，限制了造血干细胞移植在临床的应用。我们曾探讨了持续稳定表达人FL(FLT3配体)和GMCSF(粒-巨噬细胞集落刺激因子)的转基因基质细胞系对CD34^ 细胞具有扩增作用，而在CD34^ 细胞中只有CD34^ 、CD38^-细胞才可使造血功能重建。本实验拟通过已建立的持续稳定表达人FL转基因基质细胞系，进一步探讨FL基因修饰的骨髓基质细胞对人脐血造血干细胞的体外扩增作用。     

外周血干细胞动员调节CD34^＋细胞β整合素及L—选择素的表达

目的：观察造血干细胞表面粘附分子的变化在外周血干细胞动员中的作用。方法：用双色免疫荧光法研究15例恶性血液病患者经化疗＋G－CSF动员外击血干细胞前后、骨髓和外周血CD34^ 细胞表面β1整合素（CD49d）、β2整合素（CD11a、CD11b）及L－选择素（CD62L）的表达。结果：①动员后第7天CD34^ 细胞表面较动员前CD49d、CD11a、CD62L表达下降;（P＜0．01）,而CD11b无变化（P＞0．05）。②外周血CD34^ 细胞表达CD49d、CD11a、CD11b、CD62L较骨髓低（P＜0．05）。③外周血CD34^ 细胞绝大多数处于GO／G1期,该期的的干细胞CD49d的密度低于S＋G2／M期。结论：化疗＋G－CSF通过粘附分子的变化而使造血干细胞从骨髓进入外周血中。     

Interleukin-15 Promotes the Commitment of Cord Blood CD34^＋ Stem Cells into NK Cells

Naturalkiller(NK)cellsweresubgroupoflymphocytes thatplayedanessentialroleinthecellularbasedimmune defenseagainstvirus infectedandtransfectedcells.His torically,inteleukin 2(IL 2)wasregardedasthenatural activatorforNKcells.Recently,itwasdiscoveredthat IL …     

转染IL-21的CD34~+脐血造血干细胞抗裸鼠卵巢癌作用研究

目的 探讨IL-21转染的脐血造血干细胞(CD34~+UBSC·IL-21)对荷卵巢癌裸鼠的治疗作用.方法 从脐血分离CD34~+造血干细胞,体外培养扩增后用于重组体pIRES2-IL-21-EGFP转染.以肿瘤大小、荷瘤鼠生存期判断CD34~+UBSC-IL-21对荷瘤裸鼠的治疗效应.以RT-PCR、免疫荧光、ELISA、Western blot、脾细胞增殖试验及免疫组化法分别鉴定CD34~+UBSC和肿瘤组织中IL-21的表达及活性.裸鼠脾细胞中NK细胞含量及脾细胞的杀伤效应、血清中IFN-γ和TNF-α水平分别用FCM与ELISA检测.结果 pIRES2-IL-21-EGFP成功转染CD34~+UBSC.CD34~+UBSC-IL-21能抑制肿瘤生长,延长荷瘤裸鼠生存期,治疗鼠肿瘤局部能表达IL-21、血清IFN-γ和TNF-α水平升高,NK细胞含量及NK细胞杀伤活性明显增强,与其他组相比,差异有统计学意义(P<0.01).结论 转染IL-21的CD34~+UBSC有良好的抗裸鼠卵巢癌作用,该结果为临床使用UBSC为载体的基因治疗卵巢癌研究奠定了基础.     

Effect of IL-21 on NK cells derived from different umbilical cord blood populations

IL-21 plays a role in the proliferation and maturation of NK cells developed from hematopoietic stem cells. In this study, we found that IL-21, in the presence of physiological concentration of hydrocortisone (HC), has a significant impact on the functions of NK cells derived from umbilical cord blood (CB) populations. We demonstrate that IL-21, in combination with Flt3-ligand, IL-15 and HC, induces high proliferative responses and, apart from enhancing NK-mediated cytotoxicity, it also induces a significant increase in lymphokine-activated killer activity of CB/CD34+-derived CD56+ cells. In addition, IL-21 induced changes in the CD56+ cell cytokine secretion profile. Thus, we observed increased levels of IL-10 and granulocyte macrophage colony-stimulating factor, whereas tumor necrosis factor-alpha levels decreased. IFN-gamma production was also modified by IL-21, depending on the presence or absence of IL-18. CB/CD34+ cells did not express the IL-21R ex vivo, but receptor expression was induced during their commitment to differentiation into CD56+ cells. Our data ascribe to IL-21 an essential role on NK cell development and function under conditions similar to the in vivo CB microenvironment.     

CD34+ cells cultured in stem cell factor and interleukin-2 generate CD56+ cells with antiproliferative effects on tumor cell lines

In vitro stimulation of CD34+ cells with IL-2 induces NK cell differentiation. In order to define the stages of NK cell development, which influence their generation from CD34 cells, we cultured G-CSF mobilized peripheral blood CD34+ cells in the presence of stem cell factor and IL-2. After three weeks culture we found a diversity of CD56+ subsets which possessed granzyme A, but lacked the cytotoxic apparatus required for classical NK-like cytotoxicity. However, these CD56+ cells had the unusual property of inhibiting proliferation of K562 and P815 cell lines in a cell-contact dependent fashion.     

G-CSF-mobilized CD34+ cells cultured in interleukin-2 and stem cell factor generate a phenotypically novel monocyte

To study the early stages of development from stem cells of the CD56+ cell population [which includes natural killer (NK) cells], granulocyte-colony stimulating factor-mobilized peripheral blood CD34+ cells from healthy donors were sorted to >99% purity and cultured in the presence of stem cell factor and interleukin (IL)-2. After 3 weeks in culture, the majority of cells acquired CD33, with or without human leukocyte antigen-DR and CD14. In 20 stem cell donors tested, 8.7 +/- 8.8% of cells were CD56+. Two major CD56+ subsets were identified: CD56(bright), mainly CD33- cells (7+/-10%, n=11) with large, granular lymphocyte morphology, and CD56dim, mainly CD33+ (2.5+/-2, n=11) cells with macrophage morphology. The CD56bright population had cytoplasmic granzyme A but lacked killer inhibitory receptor, suggesting they were immature NK cells. The CD56dim, CD33+, population lacked NK markers. They may represent a minor subset of normal monocytes at a developmental stage comparable with the rare CD56+ CD33+ hybrid myeloid/NK cell leukemia. Consistent with a monocyte nature, CD56dimCD33+ proliferated and produced a variety of cytokines upon lipopolysaccharide stimulation, including IL-8, IL-6, monocyte chemoattractant protein-1, and macrophage-derived chemokine but not interferon-gamma. In a short-term cytotoxicity assay, they failed to kill but powerfully inhibited the proliferation of the NK-resistant cell line P815. The generation of CD56+ cells was negatively regulated by hyaluronic acid and IL-4, indicating that extracellular matrix may play an important role in the commitment of CD34+ cells into CD56 myeloid and lymphoid lineages.     

NK cells differentiated from bone marrow,cord blood and peripheral blood stem cells exhibit similar phenotype and functions

In the present study, we investigated the differentiation of human NK cells from bone marrow, cord blood and mobilized peripheral blood purified CD34⁺ stem cells using a potent culture system. Elutriated CD34⁺ stem cells were grown for several weeks in medium supplemented with stem cell factor (SCF) and IL-15 in the presence or absence of a murine stromal cell line (MS-5). Our data indicate that IL-15 induced the proliferation and maturation of highly positive CD56⁺ NK cells in both types of culture, although murine stromal cells slightly increased the proliferation of NK cells. NK cells differentiated in the presence of MS-5 were mostly CD56⁺ CD7⁻ and a small subset expressed CD16. These in vitro differentiated CD56⁺ NK cells displayed cytolytic activity against the HLA class I ⁻ target K562. The CD56⁺ CD16⁺ subset also lysed NK-resistant Daudi cells. Neither of these NK subsets were shown to express Fas ligand. Total CD56⁺ cells expressed high amounts of transforming growth factor-β and granulocyte-macrophage colony-stimulating factor, but no IFN-γ. Investigation of NK receptor expression showed that most CD56⁺ cells expressed membrane CD94 and NKG2-A mRNA. PCR analysis revealed that p58 was also expressed in these cells. The role of CD94 in NK cell-mediated cytotoxicity was assessed on human HLA-B7-transfected murine L cells. While a low cytotoxic activity towards HLA-B7 cells was observed, the HLA-DR4 control cells were killed with high efficiency. These studies demonstrate that cytolytic and cytokine-producing NK cells may be derived from adult and fetal precursors by IL-15 and that these cells express a CD94 receptor which may influence their lytic potential.     

Importance of stromal determinants in the generation of dendritic and natural killer cells in the human spleen

Summary The interaction between stroma and blood cells in the human spleen has received little attention, despite their well-defined roles during blood cell development in bone marrow. We have reported previously that human spleen-derived fibroblasts display a differentiated myofibroblast phenotype and constitutively express a biologically active form of membrane interleukin (IL)-15 that can drive co-cultured CD34(+) blood cells to differentiate into activated natural killer (NK) cells. Here, we show that, in addition to NK cells, CD34/fibroblast co-cultures also yield myeloid CD1a(+)CD38(+)CD68(+)CD86(+) HLA-DR(+)CD14(-)CD80(-) dendritic cells (DCs) after 3-4 weeks in culture. We found that DC development depended on endogenously secreted stromal macrophage colony-stimulating factor (M-CSF) and CD40/CD40L interaction rather than on fibroblast- and CD34-derived membrane IL-15. CD1a(+) cells were necessary for co-produced NK cells to acquire lytic functions by a mechanism involving cell-to-cell contact and DC-derived IL-12. This study highlights the importance of spleen myofibroblasts in the in vitro generation of two distinct cell types (DC and NK cells) from the innate immune system and suggests that the human spleen is involved in the generation of NK cells from circulating progenitors.     

猕猴骨髓干细胞动员后外周血干细胞、免疫细胞亚群及细胞因子变化

目的:观察GM-CSF动员猕猴骨髓干细胞后外周血干细胞、免疫细胞亚群和细胞因子含量的动态变化,为临床干细胞动员及用于治疗疾病提供参考依据.方法:健康猕猴连续5 d,皮下注射GM-CSF 8 μg/(kg·d),分别于0、2、4、6、8、10 d采集外周血,血细胞分析仪计数白细胞(WBC)总数、淋巴细胞和中性粒细胞比例,流式细胞术(FCM)测定CD34 、CD133 、CD3 、CD4 、CD8 、CD56 细胞比例,酶联免疫分析法测定血清TNF-α、IL-1β、IL-2含量.结果:WBC、中性粒细胞、CD34 、CD133 细胞数量和比例均同步升高(P＜0.01),到动员第6天时达到高峰,细胞数量分别为正常水平的6.4、9.1、117和163.3倍,其中CD34 、CD133 第8天时恢复正常,而WBC、中性粒细胞仍高于正常水平(P＜0.05).CD3 、CD4 、CD8 、CD56 细胞的数量增加,细胞数在第6天时分别为动员前的4.1、4.0、2.9和4.3倍,但比例下降(P＜0.01),到第6天达到最低(P＜0.001),随后逐渐升高至正常以上水平并持续至第10天(P＜0.05).TNF-α、IL-1β、IL-2浓度于动员后6 d内明显升高(P＜0.01),其中TNF-α、IL-1β浓度至8 d恢复正常(P＞0.05),IL-2浓度升高幅度较大并至少持续至第10天(P＜0.01).结论:连续5 d动员猕猴骨髓干细胞可使外周血中CD34 、CD133 细胞比率短暂升高,WBC、中性粒细胞比例持续升高,使CD3 、CD4 、CD8 、CD56 细胞绝对数增加,TNF-α、IL-1β、IL-2浓度升高,表明GM-CSF动员猕猴骨髓干细胞可在细胞和免疫调节因子水平提高免疫功能.     

NK 细胞的高效扩增及其对体外肿瘤模型的杀伤效果研究

目的:高效扩增NK 细胞,并确定其对不同肿瘤的杀伤作用,为临床应用提供参考。方法:从成人外周血中分离PBMCs 并利用表面表达4-1BBL、IL-15 和IL-21 的K562 滋养细胞对其进行共刺激培养,15 d 后计数并检测CD3- CD56+细胞纯度;利用间接免疫荧光及Real-time PCR 方法检测NK 细胞Granzyme B 及Perforin 表达变化的同时检测其对肺癌、胃癌、肝癌、卵巢癌、胰腺癌、宫颈癌的杀伤作用,确定其对不同肿瘤的杀伤效果。结果:扩增15 d 后,细胞数量高于110 ‘,CD3-CD56+比例达95%以上;培养后的NK 细胞高表达Granzyme B、Perforin,且对A549 的杀伤效果(E:T=10 :1)约为90%,同时对其他肿瘤细胞(E:T=10:1)的杀伤效果由强到弱的顺序为:胃癌、胰腺癌、宫颈癌、卵巢癌、肾癌、肝癌(P<0.05);NK 细胞对宫颈癌、肝癌、胰腺癌的杀伤效果呈现一定的时间依赖性。结论:此方法可以扩增出高数量、高纯度的NK 细胞,同时该NK 细胞具有高效杀伤多种肿瘤细胞的能力。     

The generation of human dendritic and NK cells from hemopoietic progenitors induced by interleukin-15.

Interleukin-15 (IL-15) is a pleiotropic cytokine that induces the generation and differentiation of lymphoid cells and shares many biological activities with IL-2. We have shown here the development of dendritic cells (DC) from human CD34+ hemopoietic precursor cells cultured for 2-4 weeks with IL-15 alone. DC generated with IL-15 have typical morphological, immunocytochemical, phenotypic, and functional characteristics of mature DC. Dual flow cytometry analysis performed weekly demonstrated increasing co-expression of CD1a or CD83 with HLA-DR, CD80, CD86, IL-2R alpha, beta, and gamma. Two populations of cells were distinguished among CD34+ progeny. Small and medium-size cells were mainly natural killer (NK) cells (72.6-85.2% CD56+) and low numbers of DC (9.1-21.3% CD1a+). Large cells were mostly DC (75.4-95.4% CD1a+). Isolated CD34+ cells did not express IL-2R subunits but after 2-3 days in culture with IL-15, they were found to express IL-2Rgamma. Induced expression of IL-2Rgamma on CD34+ cells may explain the primary mechanism of IL-15-regulated differentiation of hemopoietic precursor cells. Thus, our data suggest that IL-15 stimulates CD34+ cells to differentiate into NK and DC and may represent a new growth and survival factor for lymphoid DC.