脐血CD34^＋细胞体外诱导分化为成熟巨核细胞及产出血小板

背景:据作者查新检索,国外尚无通过体外诱导干细胞生成具有功能的血细胞并形成产品的报道.目的:体外诱导脐血CD34+细胞向成熟巨核细胞分化,并观察血小板产出情况.设计、时间及地点:细胞学体外观察,于200412006在湘雅医院及湘雅三医院中心实验室完成.材料:脐带来源于足月妊娠健康产妇,由湘雅医院提供.方法:免疫磁珠法分选脐血CD34+细胞,按5×107L-1密度接种于24孔培养板,加入含L-谷氨酰胺、铁饱和的人转铁蛋白、CaCl2、胰岛素、去离子牛血清白蛋白及重组人血小板牛成素的StemPro-34无血清培养基,置于37℃、体积分数为0.05的CO2饱和湿度条件F向巨核细胞诱导培养14～21d.吸取细胞培养液,离心取上清,再次离心弃上清,余下物质即为细胞培养液中比重较小的血小板样颗粒.同法分离正常富血小板血浆中的血小板.主要观察指标:培养细胞与上清液中血小板样颗粒的形态变化、免疫组织化学染色结果、显微及超微结构观察,血小板聚集情况及CD41的表达.结果:培养第10天,巨核细胞诱导培养体系中出现丝状物质,片有血小板样颗粒产生,第16天达高峰:培养细胞强阳性表达血小板特异件抗原GP Ⅱb Ⅲa:光镜观察培养细胞呈成熟巨核细胞形态,但也可见幼稚巨核细胞样,巨核细胞旁可见血小板样颗粒:电镜观察培养细胞大多呈成熟巨核细胞形态,少量呈凋亡状态,上清液中血小板样颗粒与富血小板血浆中的血小板大小、超微结构基本一致,有的血小板表面光滑,有的则呈现不规则表面.上清液中血小板样颗粒与正常富血小板血浆中的血小板均能对凝血酶产生聚集反应,流式细胞仪检测两者具有同样的CD41高表达率.结论:脐血CD34+细胞能在体外诱导生成高纯度且成熟的巨核细胞,并产出血小板.     

In vitro clinical-grade generation of red blood cells from human umbilical cord blood CD34+ cells

BACKGROUND: There is no appropriate alternative source of red blood cells (RBCs) to relieve the worsening shortage of blood available for transfusion. Therefore, in vitro generation of clinically available RBCs from hematopoietic stem cells could be a promising new source to supplement the blood supply. However, there have been few studies about the generation of clinical‐grade RBCs by coculture on human mesenchymal stem cells (MSCs) and various cytokine supplements, even though the production of pure RBCs requires coculture on stromal cells and proper cytokine supplements. STUDY DESIGN AND METHODS: Umbilical cord blood (CB) CD34+ cells were cultured in serum‐free medium supplemented with two cytokine sets of stem cell factor (SCF) plus interleukin‐3 (IL‐3) plus erythropoietin (EPO) and SCF plus IL‐3 plus EPO plus thrombopoietin (TPO) plus Flt‐3 for 1 week, followed by coculture upon MSCs derived from bone marrow (BM) or CB for 2 weeks. RESULTS: Almost pure clinical‐grade RBCs could be generated by coculturing with CB‐MSCs but not BM‐MSCs. Expansion fold and enucleation rate were significantly higher in coculture with CB‐MSCs than BM‐MSCs. Despite a 2.5‐fold expansion of erythroblasts in the presence of TPO and Flt‐3 for 8 days, the final RBC count was higher without TPO and Flt‐3. CONCLUSIONS: This study is the first report on generating clinical‐grade RBCs by in vitro culture with human MSCs and compared effectiveness of several cytokines for RBC production. This provides a useful basis for future production of clinically available RBCs and a model of erythropoiesis that is analogous to the in vivo system.     

两步法从脐血CD34+细胞获得大量树突细胞的初步研究

目的　探索利用先扩增后诱导的“两步法”从脐血 (CB)CD34 细胞高效大量地获得树突细胞 (DC)。方法　免疫磁珠法从CB分选获得CD34 细胞 ,以干细胞因子 (SCF)、IL 3、Flt 3配体 (FL)、Tpo组合刺激 ,扩增 7d、10d和 14d(依次为Ⅰ、Ⅱ和Ⅲ组 )后以GM CSF IL 4 TNF α诱导 8d或 5d获得DC ,通过相差显微镜、电镜观察形态 ,流式细胞仪检测表型 ,混合淋巴细胞培养、ELISA法检测培养液上清IL 12含量评价其功能。结果　CBCD34 细胞经SCF IL 3 FL Tpo刺激扩增 7d、10d和 14d后细胞总数分别扩增了 (5 3.39± 2 0 .5 9)倍、(30 7.17± 119.5 9)倍和 (1117.2 5± 335 .4 9)倍。经GM CSF IL 4 TNF α诱导 8d后所得CD1a 细胞是扩增前细胞数的 (2 1.4 0± 16 .70 )倍、(14 3.2 0± 6 0 .35 )倍和(15 0 .80± 4 2 .16 )倍 ,Ⅱ、Ⅲ组明显多于Ⅰ组 (P <0 .0 5 ) ,但Ⅱ、Ⅲ组间无显著性差异 (P >0 .0 5 )。所得DC的形态、表型及刺激异基因T细胞增殖能力、IL 12分泌量 ,三组无显著性差异 (P >0 .0 5 )。当诱导时间缩短至 5d时 ,各组DC功能均显著下降 (P <0 .0 5 )。结论　CBCD34 细胞扩增 7～ 10d再诱导 8d可以高效大量获得具有正常功能的DC ,而扩增时间超过 10d并不能显著增加DC产量 ,诱导时间少于8d将降低所得DC     

脐血CD34^＋细胞和外周血单核细胞两种来源的树突状细胞特性？…

目的 体外大量扩增和纯化具有典型表型、形态和功能的树突状细胞（ＤＣ）、以进行相关基础研究和临床应用。方法 采用免疫磁珠江分离脐血ＣＤ３４＾＋细胞及外周血去Ｂ、去Ｔ淋巴细胞的单个核细胞（单核细胞）,然后以ＧＭ－ＣＳＦ、ＩＬ－４、ＴＮＦα、Ｆｌｔ３配基（ＦＬ）、ＳＣＦ等不同的细胞因子配伍分别诱生ＤＣ,通过流式细胞仪、电镜、光镜分析其特性,同时检测其刺激同种Ｔ细胞增殖的能力。结果 脐民外周血诱生ＤＣ的方     

脐血CD34+细胞体外扩增诱导成熟树突状细胞实验研究

目的建立体外诱导和扩增人脐血树突状细胞（DC）的方法,并进行生物学鉴定。方法脐血细胞经免疫磁珠法分离纯化为CD34^＋细胞,加入细胞因子（GM-CSF和TNF-α培养约2周,光镜观察培养的DC形态学特征;通过与同种T细胞混合培养,采用MTT比色分析法测定不同浓度的DC激发同种T细胞增殖的能力。结果培养的DC胞浆突起大而长,呈树突状,具有DC的典型形态,并且具有强烈的激发同种异体T细胞增殖的能力。结论从脐血细胞分离纯化CD34^＋细胞,加入细胞因子（GM-CSF和TNF-α培养,能获得大量、较高纯度的DC。DC具有强烈的激发同种异体T细胞增殖的能力。     

人脐血CD34+CD38-细胞免疫表型和染色体核型特征分析

目的 分离脐血干／祖细胞(CD34^ CD38)进行体外长期培养，观察分析其增殖、细胞表面分子标志和染色体核型的特征。方法 用流式细胞仪分选CD34-FITC和CD38-PE标记的CD34^ CD38脐血原始细胞，在含细胞生长因子IL-3、IL-6、GM-CSF、EPO、SCF和胰岛素样生长因子的干细胞培养基中培养6个月，用流式细胞术检测体外培养30d的干／祖细胞表面标记，并用G显带方法分析其染色体核型。结果 在一定培养条件下，经7～12d培养，脐血干／祖细胞(CD34^ CD38)开始增殖。培养6个月后，每孔接种1个细胞，细胞数增殖至250～350个；每孔接种10个细胞，细胞数可增殖至400～500个。每孔接种1个细胞其细胞增殖峰持续时间(8～9代)比接种10个细胞(6～7代)长：经体外长期培养增殖，细胞仍强烈显示十／祖细胞表面分子标记(CD34^ CD38^-)；细胞染色体数目、结构未见异常。结论 脐血干／祖细胞(CD34^ CD38^ )经体外特异性培养增殖，可为大量脐血干／祖细胞移植提供细胞来源。     

脐带间充质干细胞对脐血CD34＋细胞体外扩增的影响

背景:体外扩增是目前解决脐带血干细胞移植所面临的单份脐血造血干祖细胞数不足问题的丰要手段.已有许多关于不同来源的间充质干细胞联合不同细胞因子支持脐血造血干祖细胞体外扩增的报道,而单独应用间充质干细胞对人脐血CD34+细胞体外扩增的报道仍很少.目的:观察应用脐带源间充质干细胞作基质层的体外培养体系对脐血CD34+细胞体外扩增的支持作用.设计、时间及地点:对比观察实验,于2006-03/2007-05在中国医学科学院中国协和医科大学血液学研究所、实验血液学国家重点实验室完成.材料:经产妇知情同意,采集健康足月分娩胎儿脐带9份.方法:应用贴壁培养的方法从正常足月出生儿脐带中分离培养间充质干细胞,通过细胞形态学、免疫表型、分化实验进行鉴定.利用免疫磁珠分离法从正常足月出生儿脐带血中分离CD34+细胞.应用3种不同培养体系进行脐血CD34+细胞的体外扩增:单独应用脐带源间充质干细胞作基质层、细胞因子培养体系和间充质干细胞联合细胞因子培养体系.主要观察指标:应用细胞计数法、集落培养计数法和流式细胞学检测法对扩增后细胞数量、集落形成能力和免疫表型进行分析比较.RT-PCR检测间充质干细胞中细胞因子的表达情况.结果:培养第14天后,间充质干细胞组的CD34+细胞比例明显高于细胞因子联合间充质干细胞组;CD34+细胞总数为培养前的(4.19±1.37)倍,明显高于细胞因子组.培养第7天和第14天,间充质干细胞组的CD34+CD38-细胞亚群比例均高于另两组.RT-PCR结果显示,脐带源间充质干细胞体外可表达干细胞因子和血小板生成素早期干细胞效应因子.结论:单独应用脐带源间危质干细胞可有效地对脐血CD34+细胞进行体外扩增,更有利于保持较早期干、祖细胞的扩增.     

4-1BB ligand stimulation enhances myeloid dendritic cell maturation from human umbilical cord blood CD34+ progenitor cells

In humans, at least two subsets of dendritic cells (DCs) are identified on the basis of differential surface expression of CD11c antigens. CD11c(+) and CD11c(-) cells are respectively of myeloid and lympholoid origin and functionally distinct, eliciting inflammatory and tolerant T cell responses. We investigated whether 4-1BB ligand (4-1BBL), a member of the tumor necrosis factor (TNF) family, is involved in the maturation process to mature myeloid DCs during in vitro DC differentiation from immature DCs derived from human umbilical cord blood (CB) CD34(+) progenitor cells. Enhanced levels of CD11c as well as immunostimulatory molecules such as CD86, MHC class II, and 4-1BBL were induced in response to 4-1BBL stimulation. These changes were accompanied by noticeable morphological transition from nonadherent to adherent myeloid-like DCs. Stimulation of 4-1BBL on DCs with 4-1BB-Fc or with 4-1BB-transfected Jurkat cells resulted in acquisition of capacity for the immature DCs to produce interleukin-12 (IL-12). This suggests that 4-1BBL may be an important mediator for maturation of CD11c(+) myeloid DCs, information of possible relevance for the design of DC-based vaccines with enhanced activity.     

肿瘤坏死因子α和白细胞介素4对脐血CD34+造血干细胞来源的树突状细胞体外培养体系的影响

背景：造血干细胞是构筑免疫系统的最早的细胞，能分化为多种细胞，其中具有包括免疫应答调控树突状细胞。树突状细胞的诱导培养因前体细胞来源不同，所采用的细胞因子，及最佳的细胞因子配伍、应用顺序、实验室培养条件亦不相同，树突状细胞的发育、各种表型的表达及成熟度也不尽相同。目的：观察肿瘤坏死因子α和白细胞介素4对脐血CD34＋造血干细胞来源的树突状细胞诱导培养体系的影响，探寻该培养体系优化方法。设计、时间及地点：观察性实验，于2005—03／11在南京医科大学微生物与免疫学实验室完成。材料：健康新生儿脐血为南京市八一医院产妇同意捐赠。CD34单克隆抗体-磁珠分离系统为德国MiltenyiBiotec公司产品；重组人粒细胞巨噬细胞集落刺激因子（GM—CSF）、重组人白细胞介素4和重组人肿瘤坏死因子α为美国PeproTech公司产品。方法：淋巴细胞分离液分离获得脐血单个核细胞，免疫磁珠阳性分选CD34＋造血干细胞，并用流式细胞术鉴定CD34＋造血干细胞纯度；比较GT（GM-CSF＋肿瘤坏死因子α）方案和GTI（GM-CSF＋肿瘤坏死因子α＋白细胞介素4）方案及GTI方案中肿瘤坏死因子α和白细胞介素4不同时段加入对诱导培养产生的树突状细胞成熟的影响；通过激光共聚焦显微镜观察细胞形态，流式细胞仪分析细胞表型及3H-TdR检测树突状细胞激发异体T细胞增殖能力。结果：免疫磁珠阳性分选CD34＋造血干细胞纯度可达90％以上。将CD34＋造血干细胞按GT方案和GTI方案进行培养，均可诱导产生树突状细胞，CD34的阳性表达率逐渐下降，HLA-DR的表达下降（P〈0．05），树突状细胞的相关分化抗原CD80，CD86，CD83和CDla的表达均相应增加，培养13～15d的细胞各表型表达较7-9d，10～12d充分。但经GT方案诱导的树突状细胞CD14表达较高，CD80，CD86，CD83，CD1α表达不如经GTI方案诱导的高；而GTI方案中，以肿瘤坏死因子Q0h、白细胞介素448h加入诱导培养的树突状细胞各表型表达相对较佳，其细胞表达CD80，CD86均较其他组高，尤以CD86表达为著，并具有激发异体T细胞增殖能力。结论：CD34＋造血干细胞经过合适的培养体系能够诱导分化为功能性树突状细胞，以GM-CSF与肿瘤坏死因子α0h加入、白细胞介素448h加入的GM-CSF＋肿瘤坏死因子α＋白细胞介素4方案更为可取。     

混合脐血血浆对脐血CD34^＋细胞体外扩增的作用

采用两步法分离出脐血CD34~ 细胞,比较研究了混合脐血血浆联合IL-3,IL-6,GM-CSF,Epo 4种中、晚期造血因子和单纯的4种造血因子情况下脐血CD34~ 细胞的体外扩增。结果表明,混合脐血血浆联合造血因子对粒-巨噬细胞集落形成单位(granulocyte-macrophage colony-forming unit,CFU-GM),红系爆式集落形成单位(burst-forming unit of erythriod,BFU-E),混合集落形成单位(minxed colony-forming unit,CFU-mix)3种集落的扩增效果明显优于单纯的4种造血因子联合组,差异具有统计学意义(P<0.01),但单纯混合脐血血浆扩增效果较差。脐血造血细胞扩增对子成人脐血移植有重要意义。上述结果提示,混合脐血血浆的扩增成功,可代替或弥补早期造血生长因子的作用,用于脐血造血细胞的体外扩增。     

脐血CD34+细胞与单个核细胞的体外扩增特性研究

目的　探讨CD34+ 富集细胞和单个核细胞 (MNC)的体外扩增特性。方法　利用Min iMACS系统富集CD34+ 细胞 ,在相同条件下与同批MNC进行对照培养 ;观察了再次富选和MNC培养上清 (MNC SN)对CD34+ 富集细胞扩增的影响 ;并尝试了MNCCD34- 细胞的培养。结果　虽然CD34+ 富集细胞具有很高的扩增潜力 ,但在培养过程中 ,其集落密度和CD34 + 细胞含量却始终呈下降趋势 ,而MNC在培养中却出现了一个上升的趋势 ,集落密度和CD34+ 细胞含量分别由第 0天的 (4 12± 16 7) 10 5细胞和 (1.12± 0 .4 2 ) %增至第 7天的 (116 2± 5 6 6 ) 10 5细胞和 (4 .17± 1.4 4 ) % ;再次富选可以使培养过的CD34+ 富集细胞的总细胞和CD34+ 细胞扩增能力大大提高 ;MNCCD34- 细胞具有集落形成和转化为CD34+ 细胞的能力 ;MNC SN对CD34+ 富集细胞的集落形成有促进作用 ,而同时又对CD34+ 细胞有促分化作用。结论　CD34+ 富集细胞在体外大量扩增的同时存在大量分化 ,其在培养过程中产生的CD34-细胞对CD34+ 细胞的扩增有抑制作用 ;脐血MNC中大量的CD34- 细胞含有造血干 祖细胞 ,其分泌的细胞因子有促进CD34+ 细胞向较为成熟的集落形成祖细胞分化的作用。     

High level of retrovirus-mediated gene transfer into dendritic cells derived from cord blood and mobilized peripheral blood CD34+ cells

Dendritic cells (DCs), the most potent antigen-presenting cells, can be generated from CD34+ hematopoietic stem cells and used for generating therapeutic immune responses. To develop immunotherapy protocols based on genetically modified DCs, we have investigated the conditions for high-level transduction of a large amount of CD34+-derived DCs. Thus, we have used an efficient and clinically applicable protocol for the retroviral transduction of cord blood (CB) or mobilized peripheral blood (MPB) CD34+ cells based on infection with gibbon ape leukemia virus (GALV)-pseudotyped retroviral vectors carrying the nls-LacZ reporter gene. Infected cells have been subsequently cultured under conditions allowing their dendritic differentiation. The results show that using a growth factor combination including granulocyte-macrophage colony-stimulating factor plus tumor necrosis factor alpha plus interleukin 4 plus stem cell factor plus Flt3 ligand, more than 70% of DCs derived from CB or MPB CD34+ cells can be transduced. Semiquantitative PCR indicates that at least two proviral copies per cell were detected. Transduced DCs retain normal immunophenotype and potent T cell stimulatory capacity. Finally, by using a semisolid methylcellulose assay for dendritic progenitors (CFU-DCs), we show that more than 90% of CFU-DCs can be transduced. Such a highly efficient retrovirus-mediated gene transfer into CD34+-derived DCs makes it possible to envision the use of this methodology in clinical trials.     

Mesenchymal stem cells from CD34− human umbilical cord blood

Umbilical cord blood (UCB) is well known to be a rich source of stem cells especially for haematopoietic stem cells (HSCs). Recently, mesenchymal stem cells (MSCs) have also been shown to exist in cord blood. Although MSCs have been described by a subset of surface antigens after expansion, little is known about the cell surface phenotype of undifferentiated MSCs. The aim of this study therefore was to clarify whether undifferentiated MSCs are resident among CD34^? UCB cells. CD34⁺ cells were separated from UCB mononuclear cells (MNCs) by magnetic sorting and the CD34^? cell fractions were cultured in Dulbecco's modified Eagle's medium (DMEM) with 10% foetal calf serum (FCS) and basic‐fibroblast growth factor. Isolated CD34⁺ cells were also cultured in the same medium. Adherent fibroblast‐like cells at passage 3–4 were analyzed by fluorescence‐activated cell sorting (FACS) for MSC marker expression , and standard adipogenic, osteogenic and chondrogenic assays were used to investigate their differentiation potentials. After 4–5 weeks in culture, the cells from the CD34^? fraction became confluent with flat and fibroblast‐like morphology. These cells were positively stained for the mesenchymal cell markers CD29, CD73 and CD105. In adipogenic differentiation, the cells showed oil red O positive and expressed FABP4, adipsin and proliferation‐activated receptor γ‐2 (PPARγ2 genes) associated with adipogenesis. In osteogenic differentiation, calcium accumulation and osteocalcin were detected. The cells grown in chondrogenic conditions were positively stained for human aggrecan and expressed collagen type II and Sox‐9 genes. In contrast, cells from the CD34⁺ fraction failed to generate any cells with MSC morphology under the same culture conditions. Our results showed that UCB contained MSCs which are only resident in the CD34^? fraction. The MSCs could be induced to differentiate into at least three lineage cell types, adipocytes, osteoblasts and chondrocytes.     

人脐血中CD133^＋血管内皮祖细胞的分离培养和生物学特性

目的:观察免疫磁珠法分离得到的CD133 血管内皮祖细胞的细胞表面标记及生物学特性。方法:实验于2002-11/2003-08在解放军第四军医大学西京医院烧伤外科实验室完成。①选取正常顺产或剖腹产人胎盘(解放军第四军医大学西京医院妇产科提供,产妇均知情同意)作为CD133 血管内皮祖细胞的标本来源。②人胎盘脐血ACD-B抗凝,稀释后取7mL脐血缓慢加入淋巴细胞分离液3mL,2100r/min离心30min,取棕黄色层低密度单个核细胞,洗涤去血小板。免疫磁珠与FITC-CD133单抗室温孵育30min,洗去多余单抗,将包被FITC-CD133的免疫磁珠加入到单个核细胞中,室温孵育30min,置于磁场中1min,吸弃细胞悬液,加入磁珠-细胞分离液从免疫磁珠上释放出CD133 血管内皮祖细胞。加入EGM-2MV培养基,接种于包被I型胶原的培养瓶中,24h换液除去未贴壁细胞,3d后半量换液,培养3～4周。③观察CD133 血管内皮细胞经免疫磁珠分离后的形态变化;采用流式细胞仪分析CD133 血管内皮祖细胞在脐血单个核细胞的比例及免疫磁珠的分离效率;免疫荧光及酶组织化学检测CD133 血管内皮祖细胞体外培养不同时期的表形变化;透射电镜观察成熟血管内皮细胞W-P小体的形成情况。结果:①CD133 血管内皮祖细胞体外培养形态观察:贴壁小细胞团在4～5d可见伪足伸出,7d后呈克隆状迅速生长,2～3周后密集区细胞呈“鹅卵石”样,培养4周融合后的细胞呈梭形。②CD133 血管内皮祖细胞分离率检测结果:CD133 血管内皮祖细胞在脐血单个核细胞中的比例为0.91%,经免疫磁珠分离后比例为85.52%。③CD133 血管内皮祖细胞体外培养不同时期的免疫表形变化:培养第5天极少数细胞CD133染色阳性,大部分细胞CD34及vWF染色阳性;第10天所有细胞CD133染色均呈阴性,大部分细胞CD34、vWF染色呈阳性。④成熟血管内皮细胞W-P小体的形成情况:透射电镜下培养第10天可见成熟血管内皮细胞所特有的W-P小体。结论:采用免疫磁珠法可以有效地从人脐血中分离纯化CD133 血管内皮祖细胞,不同培养时期通过CD133,CD34,vWF单抗以及透射电镜进行鉴定,证明其具有分化为成熟血管内皮细胞的能力。     

Comparison of phenotypic and functional dendritic cells derived from human umbilical cord blood and peripheral blood mononuclear cells

Dendritic cells (DC) are important accessory cells that are capable of initiating an immune response. Generation of functional DC has potential clinical use in treating diseases such as cancer. In this report, we have demonstrated the generation of functional DC from mononuclear cells isolated from human umbilical cord blood cells (UCBC) and peripheral blood cells (PBC) using a defined medium Prime Complete Growth Medium (PCGM) (GenePrime LLC, Gaithersburg, MD). DC generated using PCGM showed the typical phenotype of DC as determined by flow cytometry and electron microscopy. Further analysis of the DC using confocal microscopy showed localization of the antigen and major histocompatibility complex (MHC) molecules in the cytoplasm 3-5 days following tumor antigen loading into DC. Subsequently, the tumor antigen-MHC complex was localized on the surface of DC. DC generated from UCBC or PBC also increased (p < 0.001) the allogeneic mixed lymphocyte reaction, confirming their immune accessory functions compared to a control mixed lymphocyte reaction (MLR) without DC added. Interestingly, DC generated using PCGM medium also significantly enhanced the hematopoietic colony (CFU-C)-forming ability. Furthermore, addition of 5% DC derived from cord blood loaded with tumor antigen also significantly (p < 0.001) increased peripheral and cord blood-derived antigen-specific cytotoxic T lymphocyte (CTL)-mediated killing of human leukemic cells (K562) and breast cancer cells (MDA-231). Thus, these results show that functional DC generated from cord blood using a defined medium are a useful source of accessory cells for augmenting CTL-mediated cytotoxicity and have potential use in cellular therapy for human leukemia and breast cancer.     

A large number of mature and functional dendritic cells can be efficiently generated from umbilical cord blood–derived mononuclear cells by a simple two‐step culture method

BACKGROUND: Advances in the past two decades in dendritic cell (DC) biology paved the way to exploit them as a promising tool in cancer immunotherapy. The prerequisite for DC vaccine preparations is large‐scale in vitro generations of homogeneous, mature, and functional DCs. Frequent improvements are being made in the existing in vitro DC production protocols to achieve this goal. In our previous study we reported a large‐scale generation of mature, functional DCs from umbilical cord blood (UCB) CD34+ cells. Here we report that this method can be used for the efficient generation of DCs from UCB mononuclear cells (MNCs) and thus the hematopoietic stem cell isolation step is not essential. STUDY DESIGN AND METHODS: MNCs or CD34+ cells isolated from the same cord blood (CB) samples were used for the generation of DCs. DCs were characterized for morphology, phenotype, and functional assays including antigen uptake, chemotaxis, and mixed leukocyte reaction. Similarly DCs generated from the MNCs of same fresh and frozen CB units were compared. RESULTS: The morphologic, phenotypic, and functional characterization of the DCs generated from various sets show that they were comparable in nature irrespective of the starting population used. CONCLUSION: We conclude that the CD34+ isolation step is not essential for the generation of mature, functional DCs and thus can be eliminated. More importantly, we show that DCs can be generated with equal efficiency from the MNCs of frozen CB units. Our culture method will be useful for exploiting the potential of UCB as an additional source for allogeneic DCs in the clinical settings.