噻唑蓝法检测中药复方对人白血病CD34~+CD38~-干细胞群的影响

目的运用噻唑蓝(MTT)法检测中药益气养阴方及其拆方后的扶正组方、祛邪组方对人白血病CD34+CD38-干细胞群的影响。方法免疫磁珠分离人白血病CD34+CD38-干细胞群,MTT法检测中药复方对细胞生长的影响。结果益气养阴制剂对白血病干细胞的体外抑制率为(24.390±0.046)%,扶正组抑制率为(9.270±0.052)%,祛邪组为(9.370±0.017)%,益气养阴组与扶正组、祛邪组比较差异均有统计学意义(P<0.05),扶正组与祛邪阻比较差异无统计学意义。结论益气养阴方对白血病干细胞有明显抑制作用。     

电泳迁移率法检测中药复方对白血病CD34~+CD38~-细胞核因子-κB的影响

目的 观察中药复方对急性髓系白血病(AML)CD34+CD38-干细胞群核因子(NF)-κB的影响。方法 将符合纳入标准的30例AML患者骨髓提取单个核细胞,并进行免疫磁珠分选分离人白血病CD34+CD38-干细胞群,每一例标本分为中药原方组、扶正组、祛邪组、对照组。采用电泳迁移率法(EMSA)检测中药复方对NF-κB活化的影响。结果 NF-κB活化比较分析:中药原方组抑制NF-κB活化最明显,中药原方组与扶正组、祛邪组比较差异有统计学意义(P<0.05),扶正组与祛邪组比较差异无统计学意义(P>0.05),对照组NF-κB活化最明显。结论 中药复方可以抑制NF-κB活化,在促进细胞凋亡的层次上,此实验为中医药靶向治疗AML提供了平台。     

Autografting with peripheral blood CD34-positive cells following high-dose chemotherapy against breast cancer

We report autologous CD34+ cell transplantation performed in 3 cases of recurrent breast cancer. The hematological recovery in these cases was assessed by comparing with that in the previous cases of autologous hematopoietic stem cell transplantation performed with the same high-dose chemotherapy regimen. Patient 1 was a 32-year-old woman with pulmonary and skeletal metastases; patient 2, a 55-year-old woman with pulmonary metastases; and patient 3, a 48-year-old woman with hepatic metastases. On day 1, cyclophosphamide 1000 mg/m2 and epirubicin 130 mg/m2 were administered concurrently with granulocyte colony-stimulating factor, and peripheral blood stem cells were harvested on days 14-16. These stem cells were processed using anti-CD34 monoclonal antibody and an immunomagnetic bead device, Isolex 300i. The high-dose chemotherapy regimen consisted of cyclophosphamide 2000 mg/m2/day, div, and thiotepa 200 mg/m2/day, div on day -5, -4, and -3. The harvested CD34+ cells numbered 3.9 +/- 2.8 x 10(6)/kg (range: 0.73-7.8/10(6)/kg), and the CFU-GM, 8.3 +/- 5.6 x 10(5)/kg (range: 1.2-15.1/10(5)/kg). After the separation, the percent of CD34+ cells was 81.9 +/- 11.6% (range: 65.8-96.4%), the CD34+ cell yield, 71.8 +/- 30.2% (range: 46.0-129.6%), and the CFU-GM yield, 48.9 +/- 9.1% (range: 35.3-62.0%). At the time of transplantation, the number of nucleated cells was 0.55 +/- 0.31 x 10(5)/kg, and that of CFU-GM, 31.2 +/- 17.8 x 10(5)/kg. Comparison of the hematological recovery in these three cases with that in patients receiving an identical high-dose chemotherapy regimen revealed recovery rates significantly faster than in patients having bone marrow transplants, and approximately identical with that in peripheral blood stem cell transplantation cases.     

Inorganic arsenic induces necrosis of human CD34-positive haematopoietic stem cells

Inorganic arsenic is a major environmental contaminant known to exert immunosuppressive effects. In this study, we report toxicity of As2O3, a trivalent inorganic form, toward isolated human hematopoietic CD34+ progenitor cells. Our results demonstrate that low concentrations of As2O3 (0.1-5 microM) inhibit in vitro proliferation of CD34+ cells and their differentiation into various hematological cell lineages. These effects were associated with the induction of a necrotic process independent of caspases and likely related to mitochondrial damage. We conclude that As2O3 can impair in vitro human hematopoiesis by decreasing survival of CD34+ progenitor cells.     

CD34阳性细胞内部结构观察

目的利用电子显微镜以及原子力显微镜观察比较健康人和初发急性髓细胞白血病患者来源的CD34阳性细胞内部结构。方法将健康人和初发急性髓细胞白血病(M2b)患者各1例骨髓中提纯出来的CD34阳性细胞制成树脂包埋块,利用超薄切片机切成厚度为60nm的薄片,分别进行透射电子显微镜和原子力显微镜观察。结果研究对象纯化前CD34阳性细胞平均比例为(1．63±0．25)％,纯化后的平均比例为(95±2．4)％。电子显微镜和原子力显微镜均可观察健康人和初发急性髓细胞白血病患者的CD34阳性细胞内部结构,不能发现两种来源细胞有特异性差别。当原子力显微镜成像范围在10μm×10μm时,可分辨出核仁和部分细胞质内线粒体等细胞器;当原子力显微镜成像范围在2μm×2μm时,细胞内部结构变模糊,被细小的树脂颗粒所掩盖,不能分辨细胞结构。结论电子显微镜和原子力显微镜均可观察细胞的内部结构,不能发现健康人和初发急性髓细胞白血病患者两组来源的CD34阳性细胞内部有特异性差别,原子力显微镜观测细胞内部结构效果并不优于电子显微镜。     

Ex vivo zidovudine (AZT) treatment of CD34+ bone marrow progenitors causes decreased steady state mitochondrial DNA (mtDNA) and increased lactate production

Haematopoietic suppression is one of the dose-limiting side effects of chronic zidovudine (AZT) therapy. We tested the hypothesis that AZT would reduce mitochondrial DNA (mtDNA) content in haematopoietic progenitors causing impaired haematopoiesis and mitochondrial dysfunction. We studied the effects of AZT 0-50 microM in vitro, on normal human CD34+ haematopoietic progenitor cells cultured ex vivo for up to 12 days. The mean AZT IC50 for granulocyte (phenotype CD15+/CD14-) and erythroid (phenotype glycophorin+/CD45-) cell proliferation was 2.5 microM (SD+/-0.7) and 0.023 microM (SD+/-0.005), respectively. In myeloid-rich cell cultures, the mean lactate content of the media, compared to untreated controls, increased by 86% (SD+/-23) at 10 microM AZT and in erythroid-rich cultures it increased by 134% (SD+/-24) in the presence of 0.5 microM AZT. In myeloid-rich cultures the AZT IC50 for the reduction in the mitochondrial/nuclear DNA content ratio was 5.6 microM, whereas in erythroid rich cultures this AZT IC50 was < 0.0005 microM. AZT produced concentration-dependent inhibition of CD34+ progenitor proliferation into both myeloid and erythroid lineages; erythropoiesis was more sensitive than myelopoiesis. Concurrently, AZT reduced steady state mtDNA content, while increasing lactate production. These findings support the hypothesis that mtDNA is one of the intracellular targets involved in the pathogenesis of AZT-associated bone marrow progenitor cell toxicity.     

人脐血CD34^ 内皮祖细胞的体外分化

目的：研究人脐血CD34^ 细胞群体中内皮祖细胞在体外分化为内皮细胞的过程中,干细胞标志以及内皮细胞表型随时间的变化。方法：将免疫磁珠细胞分选法（MACS）得到的CD34^ 细胞体外培养于纤连蛋白和无纤连蛋白处理的培养皿中,以免疫细胞化学鉴定贴壁细胞的内皮标志Flk-1和vWF,并以流式细胞仪分析其干细胞标志AC133。结果：贴壁细胞的内皮标志Flk-1和vWF是逐步出现的,d3时有27.0%贴壁细胞表达Flk-1,vWF不表达,d7时已100%表达vWF和Flk-1,纤连蛋白促进贴壁细胞内皮标志Flk-1和vWF的表达,d3时的表达百分率分别为34.0%和47.0%,d7时Flk-1和vWF的表达均为100%,在培养过程中,AC133阳性细胞的比例迅速下降,但纤连蛋白对AC133的表达无显著影响。结论：在内皮祖细胞分化的过程中,干细胞标志迅速消失,向内皮细胞分化,内皮细胞的表型是逐步出现的,纤连蛋白促进内皮祖细胞的分化。     

Experimental attempt to produce mRNA transfected dendritic cells derived from enriched CD34+ blood progenitor cells

It Peripheral blood progenitor enriched CD34+ cells (PBPC) are rather often used as stem cell background in cancer patients following high dose therapy. Keeping in mind that precursor dendritic cells (DCs) originate from haematopoietic progenitor cells, purified CD34+ cells might also serve as starting cells for ex-vivo production of DC. The aim of the present study is to develop a clinical grade procedure for ex-vivo production of DC derived from enriched CD34+ cells. Various concentrations of CD34+ cells were grown in gas-permeable Teflon bags with different serum-free and serum-containing media supplemented with GM-CSF, IL-4, TNF-a, SCF, Flt-3L and INF-a. Serum-free CellGroSCGM medium for 7 days followed by CellGroDC medium in 7 days gave equal results as serum-containing medium. Following incubation, the cultured cells containing immature DCs were concentrated and transfected with tumour mRNA from human prostate cancer cell lines employing a highly efficient electroporation procedure. Thawed transfected DCs were able to elicit primary T-cell responses in vitro against antigens encoded by the prostate cancer mRNA as shown by ELISPOT assay using mock-transfected DCs as control. The results of our study show that frozen enriched CD34+ cells can be an alternative and efficient source for production of DCs for therapeutic purpose.     

CD8+/CD38+: immune activity and clinical significance in HCV patients with and without interferon therapy.

At the light of the importance of cytotoxic T lymphocyte (CTL) response during chronic hepatitis C, we carried out a study in order to evaluate the CD8+/CD38+T-cells, immunophenotypic marker of CD8+ activated cells in a selected cohort of 22 patients for four months. The patients were subdivided in two groups: A (with IFN therapy), B (without IFN therapy). The results show that in IFN-treated subjects there is a significant reduction of ALT (sign test, z = .424;p < or = .05) and that the CD8+/CD38+ present a positive correlation with HCV-RNA (r = .894; p < .05). We hypothesize that during IFN therapy the CD8+/CD38+ activity is able to oppose HCV, probably by increasing MHC I expression on the infected cells due to the IFN modulatory action, that could strengthen the immune response of CD8+ activated T-lymphocytes. These events confer the capacity to specifically respond to any viral replication and probably take part in the reduction of ALT levels by decreasing the chronic inflammation present during a defective immune response. These data show think CD8+/CD38+ marker could be a good parameter to evaluate both the viral activity and immunological status in HCV+ patients undergoing IFN treatment.     

急性髓细胞白血病CD34抗原表达及其临床意义

目的检测CD34抗原在急性髓细胞白血病(AML)中的表达,探讨其与某些临床特征及疗效的关系.方法采用流式细胞术检测AML患者骨髓白血病细胞CD34抗原及髓系与淋系抗原的表达.结果53例初治AML中CD34阳性表达22例,占41.5%.CD34抗原表达与FAB分型无明显相关,但在M3亚型中表达明显低于其它亚型.其它各髓系抗原表达在CD34+组与CD34-组无显著性差异,淋系抗原表达CD34+组明显高于CD34-组.染色体核型异常两组间无显著性差异.CD34+组与CD34-组在年龄、性别、初诊时血红蛋白浓度、白细胞与血小板计数、肝脾淋巴结肿大等均无明显性差异.CD34+组完全缓解率为40.91%,明显低于CD34-组的67.75%.结论CD34+AML对常规化疗效果差,检测CDa4抗原对预测AML疗效具有重要价值.     

Effects of azoles on human acute myelogenous leukemia blasts and T lymphocytes derived from acute leukemia patients with chemotherapy-induced cytopenia

The effects of azoles (fluconazole, ketoconazole, miconazole, itraconazole) on human acute myelogenous leukemia (AML) blasts and T lymphocytes were studied in vitro. All the azoles altered spontaneous proliferation, cytokine-dependent proliferation and constitutive cytokine secretion by native AML blasts for a subset of patients, and all the drugs then had divergent effects. All four drugs also affected the responsiveness (cytokine-dependent and mitogen-stimulated proliferation, cytokine release) of clonogenic CD4+ and CD8+ T cells derived from acute leukemia patients with chemotherapy-induced cytopenia. However, the T cell effects were also divergent and dependent on differences between various azoles, AML accessory cells and mitogenic activation signals. These drug effects may have a clinical relevance in acute leukemia patients receiving intensive chemotherapy together with azoles as prophylaxis or treatment for fungal infections: (i) effects on AML blasts may influence their susceptibility to drug-induced apoptosis; and (ii) effects on T cells may alter effector functions that mediate additional antileukemic effects in patients receiving intensive chemotherapy.     

Cancer stem cells in hematological disorders: current and possible new therapeutic approaches

An increasing body of evidence has shown that hematologic malignancies, alike normal hematopoiesis, has a hierarchical structure including a stem cell compartment with self renewal capability, endowed in a neoplastic niche bearing resemblance to its normal hematopoietic counterpart. According to experimental data on NOD-SCID mice, leukemic stem cells are characterized by a CD34+/CD38- surface profile and account for 1 in 10(3) to 1 in 10(6) of the total amount of leukemic cells. The available knowledge about leukemic stem cells (LSC) has arisen the question as to whether some targeting of LSC is achieved by current treatments; the answer is dubitative at best, with the possible exception of arsenic trioxide in promyelocytic leukemia. On the other side, the unsatisfactory results in the treatment of many hematological neoplasms has prompted many research groups to find out whether direct targeting of LSC, possibly in its niche, would result in an improvement in cure rates. This approach implies the identification of LSC specific markers, clearly distinct from their normal counterpart in order to spare normal hematopoietic stem cells. Adhesion/surface antigens, metabolic pathways involved in LSC survival and renewal, telomerase, commonly mutated genes and epigenetic phenomena have been investigated as candidate targets for newer therapeutic strategies. So far, most of the possibly effective agents have been studied in experimental models only. FLT-3 inhibitors account for a notable exception since they have resulted effective in vivo in AML with mutated, but not over expressed, FLT-3. A main task for the future is to find out whether some common LSC specific markers would be identifiable in a substantial proportion of AML cases, or whether each AML case shows a unique fingerprint of markers. In the latter event, targeting of LSC could result in an arduous task.     

Preparation of PEG-grafted immunomagnetoliposomes entrapping citrate stabilized magnetite particles and their application in CD34+ cell sorting

Immunomagnetic systems have been used for positive selection of a cell fraction from a mixture using appropriate surface markers with satisfactory results, as haematopoietic CD34+ cells. This work reports on the development of poly(ethylene glycol)-grafted (PEG) immunoliposomes loaded with citrate-magnetite stabilized particles as the separation vehicles for immunomagnetic separations. The magnetic ferrofluid was encapsulated into PEG-liposomes by the DRV methodology. The magnetoliposomes had a liposomal size of approximately 450 nm and a Fe/lipid molar ratio of 1.52+/-0.26, and were retained in the magnetic field created by the MiniMACS system. Anti-CD34 immunomagnetoliposomes with 100 mAb/vesicle were prepared by coupling the My10 mAb and bound specifically for CD34+ KG-1a cells in culture and in mixtures with CD34-cells (CHO or Jurkat). The magnetic cell sorting was carried out in cell mixtures KG-1a/CHO or KG-1a/Jurkat with different initial% of CD34+ Kg-1a cells. For 10(6) positive cells and 100 microM of immunomagnetoliposomes, the capture efficiency was > 85% and independent of the starting percentage of CD34+ cells. The decrease of the final purity, when the starting percentage of CD34+ cells decreases and, dependent of the CD34- cell line used, point to the degree of non-specific cell binding of My10-immunomagnetoliposomes as being crucial, among of the methodological aspects as the number of starting CD34+ cells. The CD34+ cells isolated retained the viability with an estimated recovery of 45-50%.     

转HOXB4基因人骨髓MSC促进脐血CD34~+细胞体外扩增

目的 研究转HOXB4基因的人骨髓间充质干细胞(MSC)对脐血CD34~+细胞体外扩增的支持作用.方法 用病毒载体质粒转染包装细胞293T,收获病毒上清(VCM)感染MSC后,用潮霉素筛选获得转HOXB4的MSC(MSC-HOX).分别将MSC(对照组)与MSC-HOX细胞(实验组)作为CD34~+细胞体外扩增的饲养层细胞,结合细胞因子Fh3/Flk3配体(FL)、促血小板生成素(TPO)、干细胞因子(SCF)和粒细胞-集落生长因子(G-CSF)体外扩增脐血CD34~+细胞10 d,收集所有脐血细胞,检测细胞总数、CD34~+细胞总数,集落细胞形成单位(CFU)数.结果 生产重组逆转录病毒可有效将HOXB4基因转入靶细胞内并表达.脐血CD34~+细胞经体外扩增10 d后,细胞总数和CFU数两组间差异无统计学意义(P>0.05),脐血CD34~+细胞总数和比例高于对照组(P<0.05).结论 转HOXB4基因的人骨髓MSC在脐血CD34~+细胞体外扩增中,可保持CD34~+细胞未分化状态,有潜在的应用价值.     

P-gp和CD_(34)在急性白血病的表达及其相关性的临床研究

目的 :初步探讨P 糖蛋白 (P gp)、CD3 4 在急性白血病 (AL)的表达及对P gp表达与CD3 4 和相关临床参数相关性进行了研究。方法 :流式细胞仪 (FCM)直接免疫荧光法测定 5 9例初发AL患者治疗前及完全缓解 (CR)后P gp、CD3 4 。结果 :P gp在ALL与AML表达无差异 (P <0 .0 5 )。CD3 4 在M2 、M5表达多 ,在AML和ALLCD3 4 表达无差异(P >0 .0 5 ) ;单因素COX分析结果 :发病时P gp+ 、CD3 4 + 均对疗效有影响。经Logrank检验 ,P gp+ 组与P gp-组的CR率及中数缓解时间有显著性差异 (X2 =11.0 5 ,P =0 .0 0 0 9)。P gp+ 与CD3 4 -组的CR率及中数缓解时间有显著性差异 (X2 =10 .5 2 ,P =0 .0 0 1)。P gp+ 与CD+ 呈正相关 (r =1.2 77,P <0 .0 5 )。一般临床参数 (年龄、性别、白细胞计数、骨髓原幼细胞数及肝脾淋巴结肿大 )对P gp的表达均无影响 (P >0 .0 5 )。结论 :P gp+ 为AL患者疗效差、预后不良的重要因素 ;CD3 4 + 是AL患者预后不良因素之一 ;在AL ,P gp+ 与CD3 4 + 具有正相关性 ,二者协同表达者CR率更低 ,疗效更差     

Immune reconstitution after autologous hematopoietic transplantation with Lin-, CD34+, Thy-1lo selected or intact stem cell products

In sequential studies, we compared immune reconstitution following high-dose chemotherapy (HDT) and stem cell transplantation (SCT) using intact mobilized peripheral blood stem cell (PSC) in intermediate grade non-Hodgkin's lymphoma (NHL) patients and CD34(+), lineage-negative (Lin(-)), Thy-1(lo) (CD34(+)Lin(-)Thy-1(lo)) stem cells in low-grade NHL patients. Cytokine expression and cellular phenotype and function were used as the basis of comparison. Despite differences in cellular composition of the stem cell grafts, immune reconstitution in both groups was similar. Significantly higher levels of type 1- and 2-associated cytokine messenger ribonucleic acid (mRNA) were observed both prior to and following transplant in the peripheral blood (PB) of both cohorts as compared to normal individuals. Similar levels of interleukin (IL)-4, IL-10, interferon-gamma (IFN-gamma), and tumor necrosis factor-alpha (TNF-alpha) messenger ribonucleic acid (mRNA) were seen in PB mononuclear cells following transplant with either product. In contrast, patients receiving isolated CD34(+)Lin(-)Thy-1(lo) cells expressed significantly higher IL-2 levels at all times examined post-transplant. Despite the high levels of cytokine gene expression and rapid restoration to pretransplant levels of CD3 cell number by day 30, T cell function and CD4:CD8 and CD4(+)CD45RA:CD4(+)CD45RO(+) ratios were significantly depressed in both cohorts compared to normal donors, and significantly lower in patients transplanted with CD34(+)Lin(-)Thy-1(lo) compared to patients receiving an intact PSC product. These data suggest that the peripheral tolerance in patients receiving HDT and an autologous SCT occurs independent of graft composition, although immune function and CD4 recovery are better facilitated by transplantation of an intact product.     

CD_7~+的急性髓细胞性白血病的临床意义

目的 :观察和探讨 CD7+ 的急性髓细胞性白血病 (AML )表达特征及它们对 AML患者预后的影响。方法 :采用间接免疫荧光法和流式细胞仪对 2 75例初诊的 AML患者进行了免疫表型检测 ,并对淋系分化抗原阳性表达率加髓系分化抗原阳性表达率大于 10 0 %患者的白血病细胞用流式细胞仪做双标记分析。结果 :2 75例 AML患者中 ,3 6例表达淋系分化抗原 CD7(占 13 .1% ) ;诱导化疗疗效方面 ,在同等化疗强度的基础上 ,CD34+ CD7+ AML患者的缓解率明显低于 CD34- CD7- AML 患者 (P<0 .0 5 )。结论 :CD7+ AML 的表达具有复杂性、异质性 ,属于一种预后不良的临床亚型 ,应进一步探索针对性的治疗策略     

Exploiting CD38-mediated endocytosis for immunoliposome internalization

CD38 appears to be a promising candidate in antibody therapy; it is upregulated on cell surfaces in many lymphoid tumors and undergoes rapid internalization after interaction with antibodies. The receptor-mediated endocytosis allows conjugating toxins/drugs that promote suicide only of the malignant cells. Here, we describe the preparation of CD38-immunoliposomes and test their functionality by incubating them with CD38+/- cells. Liposomes were prepared by extrusion of a lipid mixture containing a biotinylated polyethylene glycol-phospholipid and loaded with 5(6)-carboxyfluorescein. The anti-CD38 antibody (IB4) was biotinylated and then linked to streptavidin molecules; streptavidin acts like a bridge between the antibody and the biotinylated lipid of the liposomes. CD38+/- cells were incubated either with liposomes or immunoliposomes and analyzed by fluorescence microscopy and cytofluorimetry. The results indicated a specific mechanism of internalization, owing to CD38-mediated endocytosis, where CD38+ cells incubated with immunoliposomes scored top fluorescence levels. This coupling strategy, based on the use of a streptavidin bridge to prepare immunoliposomes, does not interfere with the cellular functionality and its broad potential use represents a great advantage. Here IB4, a murine monoclonal anti-CD38 antibody, was used to simplify the experiments, but the coupling procedure may be suitable also with human antibodies, against CD38 or other human markers.