Generation of dendritic cells expressing bcr-abl from CD34-positive chronic myeloid leukemia precursor cells

Patients with a relapse of chronic myeloid leukemia (CML) after allogeneic bone marrow transplantation can be successfully treated with blood mononuclear cells from the original bone marrow donor. However, the antileukemic effect of this treatment is often accompanied by graft-versus-host disease (GVHD). Treatment with cytotoxic T-lymphocyte (CTL) lines or clones that are specifically generated against leukemic antigen-presenting cells from the patient, may separate antileukemic effects from GVHD. In this report we demonstrate that after culturing CD34-positive cells purified from bone marrow of patients with chronic phase CML in medium containing human serum, GM-CSF, TNF, and IL-4 up to 28% of the cultured cells were dendritic cells, characterized by morphology, phenotypic analysis, and their efficient capacity to stimulate allogeneic T lymphocytes. The expression of HLA and costimulatory molecules and the stimulatory capacity of the dendritic cell-enriched cell suspensions were optimal between days 7 and 10 after onset of the cultures. Fluorescence in situ hybridization revealed that all cultured dendritic cells contained the CML specific (9;22) translocation. PCR analysis showed expression of the translocation specific bcr-abl mRNA. These leukemic dendritic cells may enhance the induction and proliferation of CTL lines and clones with more specificity for the leukemic cells.     

Curcumin reduces expression of Bcl-2, leading to apoptosis in daunorubicin-insensitive CD34+ acute myeloid leukemia cell lines and primary sorted CD34+ acute myeloid leukemia cells

Background

Numerous pre-clinical studies and clinical trials demonstrated that induction of antibodies to the β-amyloid peptide of 42 residues (Aβ₄₂) elicits therapeutic effects in Alzheimer's disease (AD). However, an active vaccination strategy based on full length Aβ₄₂ is currently hampered by elicitation of T cell pathological autoreactivity. We attempt to improve vaccine efficacy by creating a novel chimeric flu vaccine expressing the small immunodominant B cell epitope of Aβ₄₂. We hypothesized that in elderly people with pre-existing memory Th cells specific to influenza this dual vaccine will simultaneously boost anti-influenza immunity and induce production of therapeutically active anti-Aβ antibodies.

Methods

Plasmid-based reverse genetics system was used for the rescue of recombinant influenza virus containing immunodominant B cell epitopes of Aβ₄₂ (Aβ_1-7/10).

Results

Two chimeric flu viruses expressing either 7 or 10 aa of Aβ₄₂ (flu-Aβ_1-7 or flu-Aβ_1-10) were generated and tested in mice as conventional inactivated vaccines. We demonstrated that this dual vaccine induced therapeutically potent anti-Aβ antibodies and anti-influenza antibodies in mice.

Conclusion

We suggest that this strategy might be beneficial for treatment of AD patients as well as for prevention of development of AD pathology in pre-symptomatic individuals while concurrently boosting immunity against influenza.     

Cytokine-induced expansion of human CD34+ stem/progenitor and CD34+CD41+ early megakaryocytic marrow cells cultured on normal osteoblasts

Thrombocytopenia remains a significant cause of morbidity in cancer patients undergoing allogeneic bone marrow transplantation (BMT), which consumes millions each year for frequent platelet transfusions. Using a novel culture system containing appropriate cytokine(s) on a layer of normal human osteoblasts, we investigated the expansion of early megakaryocytic progenitor cells while maintaining the number of CD34+ stem/progenitor marrow cells in an attempt to provide an effective solution for the problem of post-transplant thrombocytopenia. After seven days of culture, normal human osteoblasts alone without cytokines significantly increased the number of CD34+ and CD34+CD41+ marrow cells. Among the various cytokine combinations tested, both stem cell factor (SCF), interleukin 3 (IL-3)+IL-11 and SCF+IL-3+IL-11+thrombopoietin (TPO) emerged as the most effective in expanding early CD34+CD41+ megakaryocytic cells. Early CD34+CD41+ megakaryocytic cells have increased by 3.1- and 4.7-fold compared with day 7 control cultures, and by 62- and 94-fold, respectively, compared with day 0 input, respectively. Also, late CD41+ megakaryocytic cells have increased by 15.4- and 27.5-fold compared with day 7 control cultures in the presence of the same two combinations. In addition, the same cytokine combinations achieved 17.6- and 13.3-fold increases in the number of CD34+ marrow cells after the same seven days of culture on a layer of human osteoblasts. The combination (SCF+IL-3+IL-11+TPO) achieved the highest expansion of CD34+CD41+ early megakaryocytic cells from human marrow CD34+ cells reported so far in the literature. Recently, transplantation of SCF+IL-1+IL-3+TPO ex vivo expanded megakaryocytic progenitor cells as a supplement has been shown to accelerate platelet recovery by three to five days in mice. Therefore, the clinical use of the combination (SCF+IL-3+IL-11+TPO) for ex vivo expansion of CD34+ and megakaryocytic progenitor cells from a portion of the donor's marrow harvest is warranted in allogeneic BMT. Such a protocol would accelerate platelet recovery and shorten the period of hospitalization after allogeneic BMT. The present study has confirmed the role of human osteoblasts in supporting the proliferation and maintenance of human CD34+ stem/progenitor marrow cells. Given the facilitating role of osteoblasts shown previously in several allogeneic BMT studies in mice, it is possible to envisage a future role for donor osteoblasts in clinical BMT. Transplantation of the cultured donor osteoblasts together with the ex vivo expanded CD34+ marrow cells as a supplement might not only accelerate platelet recovery but also prevent acute graft-versus-host disease in allogeneic BMT. The present novel culture system should have useful clinical application in allogeneic BMT.     

骨髓CD34+细胞体外扩增诱导树突状细胞实验研究

目的探讨应用不同细胞因子组合方案从骨髓CD34+细胞体外扩增诱导树突状细胞(DC)的可行性及评价不同诱导方案诱导DC的效果.方法免疫磁珠法纯化骨髓CD34+细胞.在有血清条件下应用两步法SCF+FL+TPO+IL-3扩增2周,然后以GM-CSF+IL-4+TNF-α(GI方案)或GM-CSF+TNF-α(GT方案)诱导DC;或者一步法SCF+FL+TPO+IL-3+GM-CSF+TNF-α直接作用2周扩增诱导DC.通过相差显微镜、电子显微镜、流式细胞仪分析、异硫氰酸荧光素标记的葡聚糖(FITC-DX)内吞实验检测DC的生物学特性.结果诱导后细胞较0 d或诱导前细胞高表达DC相关标记(CD1a、CD80、CD86、CD40、CD54、HLA-DR).两步法GI方案诱导10 d,总细胞扩增倍数、CDla+DC扩增倍数分别为(198±178)倍和(122±129)倍,与GT方案比较无统计学意义,但诱导细胞CD1a、CD80、CD86的表达明显高于后者.一步法扩增诱导2周时总细胞数扩增(43±16)倍,CD1a+DC数是0 d接种细胞的(4±2)倍.结论两步法能从正常CD34+细胞诱导产生大量DC,GI方案优于GT方案.两者扩增效率均优于一步法.     

CD34+ corneal stromal cells are bone marrow-derived and express hemopoietic stem cell markers

Previous studies have suggested that corneal stromal keratocytes express the CD34 antigen. We wished to investigate CD34 antigen expression in normal mouse cornea using dual- and triple-staining techniques. Whole-mount preparations of mouse and rat corneas were examined with confocal microscopy using single, dual, or triple immunostaining to study their morphology, phenotype, and distribution. Single-cell suspensions from normal mouse corneas were also prepared and analyzed by flow cytometry. After short-term culture of corneal stromal explants, nonadherent cells were harvested and cytospins were prepared and stained for different markers.Combined staining for F-actin and leukocyte differentiation markers clearly showed that the corneal stroma contains a population of CD45(+) resident bone marrow-derived cells, whereas most cells were CD45-F-actin(+) keratocytes. A significant proportion (two thirds) of CD45(+) cells in the normal corneal stroma expressed CD34(+), whereas no CD45(-) cells (i.e., keratocytes) coexpressed CD34. In addition, CD34(+) cells were CD11c(-) and CD11b(+). Fewer than 10% of the CD34(+) cells also coexpressed Sca-1(+), but no CD34(+) cells coexpressed major histocompatibility complex (MHC) class II(+). In contrast, the remaining population of CD45(+)CD34(-) cells in the corneal stroma expressed CD11b, MHC class II(+) but not CD11c and were found mostly in the anterior and peripheral part of stroma. These cells are in intimate contact with corneal keratocytes, which stained only for F-actin and were negative for all leukocyte markers. Very few CD45(+) cells expressed the B220 marker, suggesting a plasmacytoid dendritic cell phenotype. Flow cytometry analyses confirmed the morphometric data showing that 68% of CD45(+) cells coexpress CD34 and CD11b, whereas 22% are CD11b(+)CD34(-).We conclude that the normal mouse cornea contains two populations of bone marrow-derived leukocytes, both of which are distinct from stromal keratocytes. The larger population resembles CD34(+) hemopoietic stem cells, whereas the smaller population are CD34(-)CD11b(+) MHC class II(+) macrophages. A very small percentage comprises plasmacytoid dendritic cells.     

脐血CD34+造血干/祖细胞基因表达图谱的研究

目的：通过脐血CD34^＋造血干／祖细胞的基因表达分析，理解造血干／祖细胞生物学特性。方法：利用MiniMACS免疫磁珠法从脐血细胞中分离CD34^＋造血干／祖细胞，提取总RNA，用SMART-PCR技术从微量RNA中扩增产生足够量的cDNA用于高密度点阵膜分析检测CD34^＋造血干／祖细胞表达的基因。结果：在所检测的588个基因中，发现63个基因具有显著的表达水平，其中18个基因强表达。这些基因主要涉及造血干细胞增殖、分化、应激响应、凋亡、转录调节以及细胞周期等。结论：对理解脐血干／祖细胞生物学性质以及指导造血干细胞体外培养提供了分子生物学基础。     

Engagement of CD33 surface molecules prevents the generation of dendritic cells from both monocytes and CD34+ myeloid precursors

Although CD33 represents an important marker of myeloid cell differentiation, its function remains poorly defined. In view of its homology with p75/AIRM1, a recently identified surface molecule which exerts a potent inhibition on NK cell function, we re-evaluated the effect of CD33 engagement in defined myeloid cell functions. Addition of anti-CD33 mAb to cultures of CD14+ monocytes supplemented with granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-4 and TNF-alpha, prevented the generation of dendritic cells. In these cultured cells, engagement of CD33 resulted in an increased surface binding of annexin-V, followed by cell death. Mature dendritic cells were resistant to the CD33-mediated effect. Also in CD34+ precursors, cultured in the presence of flt3-ligand, c-Kit-ligand, GM-CSF, IL-4 and TNF-alpha, addition of anti-CD33 mAb prevented the recovery of mature dendritic cells. These data suggest a regulatory role of CD33 in the myeloid cell maturation and may offer a tool to interfere with the monocyte/macrophage cell function as well as with the development of dendritic cells.     

抗CD40抗体联合诱导人脐血CD34+造血干细胞向DC2分化的作用

目的 探讨从脐血CD34^＋造血细胞诱导DC2的方法及CD40分子在DC2分化诱导中的作用。方法 运用磁珠从脐血中分离出CD34^＋造血干细胞,以rhIL-3（10ng／mL）、rhFlt-3L（100ng／mL）和rhGM-CSF（100ng／mL）诱导其向DC2分化,采用流式细胞仪分析DC2表型,并观察抗人CD40单克隆抗体诱导DC2分化成熟的作用。结果 人脐血CD34^＋造血细胞在rhIL-3、rhFlt-3L和rhGM-CSF联合诱导培养12d,获得具有DC2样（淋巴样DC）形态的细胞,然后分别加入rhIL-3＋抗人CD40 mAb（Ⅰ组）或rhIL-3＋TNF-α（Ⅱ组）诱导DC2的分化成熟,流式细胞仪分析细胞表型,发现Ⅰ组和Ⅱ组Lineage^-（CD3、CD14、CD16、CD19、CD56）CD123^＋细胞的HLA-DR、CD83、CD86、CD80表达率分别为88．78％、37．38％、32．83％和99．08％;78．87％、32．29％、29．57％和98．86％。结论 体外联合多种细胞因子从CD34^＋造血细胞成功地诱导出富集DC2表型的细胞,抗人CD40 mAb可以促进DC2的分化成熟。     

Down-regulation of TET2 in CD3+ and CD34+ cells of myelodysplastic syndromes and enhances CD34+ cells proliferation

Aims and background: To investigate the expressions of TET2 mRNA in bone marrow CD3⁺ and CD34⁺ cells of the patients with myelodysplastic syndromes (MDS) and to study the effect of silencing TET2 by small interfering RNA (siRNA) on the biological characteristics of CD34⁺ cells. Methods: CD3⁺ and CD34⁺ cells were sorted by magnetic activated cell-sorting system from bone marrow of MDS patients and controls. The mRNA expressions of TET2 in bone marrow CD3⁺ and CD34⁺ cells of 28 MDS patients and 20 controls were detected by qPCR. The silencing effect of RNA interference (RNAi) on TET2 expression in CD34⁺ bone marrow cells of normal control was identified by qPCR and Western blot analysis. The cell cycle kinetics and cell apoptosis were then detected by flow cytometry. Results: The expression of TET2 mRNA in CD3⁺ and CD34⁺ cells was down-regulated in MDS compared with that in controls [(0.16±0.11) vs. (1.05±0.32) (P<0.001); (0.58±0.26) vs. (1.25±0.94) (P<0.005)]. The siRNA targeting TET2 suppressed the expression of TET2 in normal CD34⁺ cells. Meanwhile, the proliferation activity was significantly enhanced [G0/G1: (87.82±8.25)% vs. (92.65±7.06)% and (93.60±5.54)%, P<0.05; S: (11.50±8.31)% vs. (6.92±7.04)% and (5.95±5.53)%, P<0.05] and the apoptosis rate was declined [(21.28±9.73)% vs. (26.17±9.88)% and (26.20±9.78)%] in the cells which transfected with TET2 siRNA as compared to those in the cells transfected with scrambled siRNA and control cells. Conclusions: The TET2 expression of in CD3⁺ and CD34⁺ cells of MDS patients was decreased. Suppression of TET2 expression renders the CD34⁺ cells harboring more aggressive phenotype. This preliminary finding suggests that CD34⁺ cells lowering expression of TET2 may play an oncogenic role on myeloid tumor and CD3⁺ T cells of MDS patients may be derived from the malignant clone.     

Role of CD34 antigen in myeloid differentiation of human hematopoietic progenitor cells

CD34 is a transmembrane protein that is strongly expressed on hematopoietic stem/progenitor cells (HSCs); despite its importance as a marker of HSCs, its function is still poorly understood, although a role in cell adhesion has been demonstrated. To characterize the function of CD34 antigen on human HSCs, we examined, by both inhibition and overexpression, the role of CD34 in the regulation of HSC lineage differentiation. Our results demonstrate that CD34 silencing enhances HSC granulocyte and megakaryocyte differentiation and reduces erythroid maturation. In agreement with these results, the gene expression profile of these cells reveals the upregulation of genes involved in granulocyte and megakaryocyte differentiation and the downregulation of erythroid genes. Consistently, retroviral-mediated CD34 overexpression leads to a remarkable increase in erythroid progenitors and a dramatic decrease in granulocyte progenitors, as evaluated by clonogenic assay. Together, these data indicate that the CD34 molecule promotes the differentiation of CD34+ hematopoietic progenitors toward the erythroid lineage, which is achieved, at least in part, at the expense of granulocyte and megakaryocyte lineages.     

Cycling G1 CD34+/CD38+ cells potentiate the motility and engraftment of quiescent G0 CD34+/CD38-/low severe combined immunodeficiency repopulating cells

The mechanism of human stem cell expansion ex vivo is not fully understood. Furthermore, little is known about the mechanisms of human stem cell homing/repopulation and the role that differentiating progenitor cells may play in these processes. We report that 2- to 3-day in vitro cytokine stimulation of human cord blood CD34(+)-enriched cells induces the production of short-term repopulating, cycling G1 CD34(+)/CD38(+) cells with increased matrix metalloproteinase (MMP)-9 secretion as well as increased migration capacity to the chemokine stromal cell-derived factor-1 (SDF-1) and homing to the bone marrow of irradiated nonobese diabetic severe/combined immunodeficiency (NOD/SCID) mice. These cycling G1 cells enhance SDF-1-mediated in vitro migration and in vivo homing of quiescent G0 CD34(+) cells, which is partially abrogated after inhibition of MMP-2/-9 activity. Moreover, the engraftment potential of quiescent G0 SCID repopulating cells (SRCs) is also increased by the cycling G1 CD34(+)/CD38(+) cells. This effect is significantly abrogated after incubation of cycling G1 cells with a neutralizing anti-CXCR4 antibody. Our data suggest synergistic interactions between accessory cycling G1 CD34(+)/CD38(+) committed progenitor cells and quiescent, primitive G0 CD34(+)/CD38(-/low) SRC/stem cells, the former increasing the motility and engraftment potential of the latter, partly via secretion of MMP-9.     

Effects of human mesenchymal stem cells on the differentiation of dendritic cells from CD34+ cells

Mesenchymal stem cells (MSCs) have profound immunomodulatory functions both in vitro and in vivo. However, their effects on the differentiation of dendritic cells (DCs) are unknown. In this study, we employed an in vitro model to investigate the effects of human MSCs on the development of DCs. CD34(+) cells isolated from cord blood were cultured under conventional DC(cDC) or plasmacytoid DC (pDC) differentiation conditions, in the presence or absence of MSCs or their conditioned medium. Here we show that both MSCs and their conditioned medium dramatically increased the numbers of cells generated under either condition. The percentage of cells with the cDC phenotype is significantly reduced in the presence of MSCs or their conditioned medium, whereas the percentage of pDC increased. The capacity of cDCs from MSCs or their conditioned medium-treated CD34(+) cells to stimulate allogeneic T cells was weakened. Furthermore, MSCs can skew the DC function from cDC to pDC, thus biasing the immune system toward Th2 and away from Th1 responses. Blocking the prostaglandin E(2) (PGE(2)) synthesis of MSCs can reverse most of these influences of MSCs on DCs differentiation and function. Therefore, MSCs can significantly influence DC development through PGE(2) production.     

Ex vivo large-scale generation of human platelets from cord blood CD34+ cells

In the present investigation, we generated platelets (PLTs) from cord blood (CB) CD34(+) cells using a three-phase culture system. We first cultured 500 CB CD34(+) cells on telomerase gene-transduced human stromal cells (hTERT stroma) in serum-free medium supplemented with stem cell factor (SCF), Flt-3/Flk-2 ligand (FL), and thrombopoietin (TPO) for 14 days. We then transferred the cells to hTERT stroma and cultured for another 14 days with fresh medium containing interleukin-11 (IL-11) in addition to the original cytokine cocktail. Subsequently, we cultured the cells in a liquid culture medium containing SCF, FL, TPO, and IL-11 for another 5 days to recover PLT fractions from the supernatant, which were then gel-filtered to purify the PLTs. The calculated yield of PLTs from 1.0 unit of CB (5 x 10(6) CD34(+) cells) was 1.26 x 10(11) - 1.68 x 10(11) PLTs. These numbers of PLTs are equivalent to 2.5-3.4 units of random donor-derived PLTs or 2/5-6/10 of single-apheresis PLTs. The CB-derived PLTs exhibited features quite similar to those from peripheral blood in morphology, as revealed by electron micrographs, and in function, as revealed by fibrinogen/ADP aggregation, with the appearance of P-selectin and activated glycoprotein IIb-IIIa antigens. Thus, this culture system may be applicable for large-scale generation of PLTs for future clinical use.     

Separation of CD34+ cells from human peripheral blood through polyurethane foaming membranes

Cell separation from peripheral blood was investigated using polyurethane (PU) foaming membranes and PU membranes (pore size, 5 or 12 mum) at different blood permeation speeds. Permeation ratio of hematopoietic stem cells (CD34(+) cells) through the PU membranes was the lowest among the blood cells at any blood permeation speed. This is thought to be because CD34(+) cells are more adhesive than red blood cells (RBCs), platelets, T cells, and B cells. Primitive hematopoietic stem and progenitor cells tend to adhere to the surface of mature blood cells, because of the high expression of cell-adhesion molecules on the surface of the cells. Human serum albumin solution was exposed to PU-COOH membranes to detach adhered cells from the surface of the membranes, allowing isolation of CD34(+) cells and reduction of RBCs in the permeate solution. Most purified CD34(+) cells (high recovery ratio of CD34(+) cells divided by recovery ratio of RBCs) were obtained in the recovery process using PU-COOH membranes (pore size, 5.2 microm) at a permeation speed of 0.3-1 mL/min.     

老年初诊急性髓细胞白血病患者CD4+CD25+调节性T细胞的表达

背景：研究证实,很多恶性肿瘤患者体内CD4⁺CD25⁺调节性T细胞存在高表达,近期也有研究发现,急性髓细胞白血病患者外周血CD4⁺CD25⁺调节性T细胞同样表现出高比例表达。 目的：分析老年初诊急性髓细胞白血病患者CD4⁺CD25⁺调节性T细胞的表达特点。 方法：纳入初诊急性髓细胞白血病患者92例,将年龄在60岁以下者设为中青年组(n=22),年龄在60岁以上者设为老年观察组(n=70)。在老年观察组中,32例经规范化疗后完全缓解,设为完全缓解组;将余下38例设为老年组,依据FAB分型标准,分为M2 6例、M3 19例、M4 7例、M5 6例。另选择同期体检健康人群42名作为正常对照组。抽取受试者外周静脉血,检测CD4⁺CD25⁺调节性T细胞表达情况。 结果与结论：老年组、完全缓解组CD4⁺CD25^highFOXP3⁺调节性T细胞比例高于正常对照组(P < 0.01),并且老年组CD4⁺CD25^high FOXP3⁺调节性T细胞比例高于完全缓解组(P < 0.01)。老年组、完全缓解组CD4⁺FOXP3⁺T细胞比例高于正常对照组(P < 0.01),并且老年组CD4⁺ FOXP3⁺T细胞比例高于完全缓解组(P < 0.01)。老年组CD4⁺CD25^high FOXP3⁺调节性T细胞与CD4⁺ FOXP3⁺T细胞比例高于中青年组(P < 0.01)。老年组不同分型间CD4⁺CD25^high FOXP3⁺调节性T细胞和CD4⁺ FOXP3⁺T细胞比例比较差异均无显著性意义(P > 0.05)。Pearson相关性检验结果显示,老年初诊急性髓细胞白血病患者外周血CD4⁺CD25^high FOXP3⁺调节性T细胞比例和CD4⁺ FOXP3⁺T细胞比例呈正相关(r=0.87,P=0.019)。表明老年初诊急性髓细胞白血病患者CD4⁺CD25⁺调节性T细胞比例高于健康人群和中青年急性髓细胞白血病患者。中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程全文链接：     

Generation of dendritic cells from lentiviral vector-transduced CD34+ cells from HIV+ donors

Dendritic cells hold promise as adjuvant for immunotherapy for cancer and infectious diseases. We demonstrate that a significant number of cryopreserved peripheral blood CD34(+) cells from HIV-infected subjects can be transduced with a replication-incompetent lentiviral vector expressing HIV antigens. In addition, untransduced and transduced CD34(+) cells from HIV-infected individuals were able to differentiate into dendritic cells with strong T-cell stimulatory capacity. Thus, cryopreserved CD34(+) cells from HIV-infected subjects may prove useful for immunotherapy for HIV/AIDS.     

两步法从慢性髓系白血病患者骨髓CD34+细胞体外扩增诱导树突状细胞

目的探讨从慢性髓系白血病(CML)患者骨髓CD34~ 细胞体外扩增诱导树突状细胞(DC)的可行性,并比较CML-DC和正常DC的生物学特性。方法免疫磁珠法从CML患者和正常供者骨髓纯化CD34~ 细胞,在有血清条件下应用两步法:干细胞生长因子(SCF) FLT3配体(FL) 促血小板生成素(TPO) 白细胞介素-3(IL-3)扩增2周,然后以粒细胞巨噬细胞集落刺激因子(GM-CSF) 白细胞介素-4(IL-4) 肿瘤坏死因子-α(TNF-α)(GI方案)诱导DC。通过相差显微镜、电子显微镜、流式细胞仪分析DC的生物学特性,荧光原位杂交(FISH)检测培养前后CML细胞的bcr/abl融合基因表达。结果诱导后细胞较0d或诱导前细胞高表达DC相关抗原(CD1a,CD80,CD86,CD40,CD54,HLA-DR)。CML患者和正常供者CD34 细胞经GI方案诱导10d,CD1a阳性率分别为36.90%±26.94%和54.35%±16.34%,CD1a~ DC数是0d接种细胞的(54±54)倍和(122±129)倍。两组相比,总细胞扩增倍数、DC扩增倍数、细胞表型均无明显差异,诱导后的DC具有相似的超微结构。CML患者CD34~ 细胞诱导10d后bcr/abl融合基因阳性率为43.67%±21.55%,具有典型DC形态的细胞bcr/abl融合基因阳性率为53.2%。结论两步法GI方案能诱导CMLCD34~ 细胞产生大量DC,诱导生成的DC不但具有正常DC的典型形态、表型,而且起源于CML细胞。