microRNA在人脐血CD34^＋CD38^-、CD34^＋CD38^＋细胞中的差异性表达

为进一步探讨microRNA（miRNA）在造血调控中的作用奠定基础,比较了miRNA在人脐血CD34^＋CD38^-、CD34^＋CD38^＋细胞中的差异性表达。从人脐血中分离单个核细胞（MNC）,应用FACSVantage分选流式细胞仪分选CD34^＋CD38^-、CD34^＋CD38^＋细胞;抽提miRNA后与miRNA芯片杂交,应用生物信息学技术分析miRNA芯片的表达结果。结果发现,miRNA在人脐血CD34^＋CD38^＋细胞的表达水平比在CD34^＋CD38^-细胞的表达水平降低至1／2以下者共11个,表达水平升高至2倍以上者共73个,以上84个miRNA被称为“干细胞性”miRNA。经比较Georgantas等和芯片表达结果,发现有12个（14、29％,12／84）相同的miRNA。部分miRNA经历了类似于CD34在造血细胞表面的发展历程。应用生物信息学技术可寻找到新的与造血调控相关的miRNA簇及miRNA的下游靶基因。结论：“干细胞性”miRNA在正常造血中发挥着重要作用,即miRNA的系统表达模式一造血干／祖细胞基因表达谱一造血干／祖细胞的自我更新和系列定向分化。     

CD133在急性白血病中的表达及其意义

目的　探讨CD133(AC133)在急性白血病 (AL)中的表达及其意义。方法　采用三色荧光流式细胞术测定 76例AL患者白血病细胞膜上CD133的表达 ;采用半定量逆转录 聚合酶链反应(RT PCR)方法测定CD133mRNA的表达。结果　①正常对照和AL患者的CD133mRNA表达与CD133蛋白表达相一致 ,AL患者CD133表达水平显著高于正常对照。②AL患者CD133及CD133mRNA高表达阳性率分别为 4 2 .1%和 4 6 .1%。急性髓系白血病 (AML)M3 患者CD133均高表达阴性 ,AML和急性淋巴细胞白血病 (ALL)的CD133高表达率分别为 4 3.4 %和 38.1% ,差异无显著性。AML M4CD133高表达阳性率显著高于其它AML亚型 ,而T ALL和B ALL的CD133高表达率分别为 2 0 .0 %和 4 3.7% ,差异也无显著性。③AML患者骨髓细胞CD133表达与CD34、HLA DR显著相关 ,ALL患者骨髓细胞CD133表达与CD34无关。④CD133表达与细胞或分子遗传学异常、发病时外周血白细胞数、乳酸脱氢酶水平、多药耐药基因 (mdr1)表达及年龄等预后因素无显著相关。⑤CD133高表达阳性组完全缓解 (CR)率及总反应 (OR)率低于高表达阴性组 ,但仅有CD34/CD133共高表达阳性组CR率低于阴性组 (44 .4 %vs71.4 % ,P <0 .0 5 ) ,差异有显著性。结论　AL患者骨髓细胞CD133表达高于正常对照 ;检测CD133表达可能有     

CD7阳性急性髓系白血病骨髓干／祖细胞5个基因表达的研究

本研究探讨abca5、mdr-1、kdr、dapk和irf-1 5个基因在CD7^＋急性髓细胞性白血病干／祖细胞的表达。利用实时定量RT—PCR（RQ—PCR）方法检测了15例正常骨髓（NBM）和16例AML患者骨髓单个核细胞（MNC）中5个基因的表达。采用流式细胞仪（FCM）分选8例NBM和21例AML患者骨髓CD34^＋CD38^＋祖细胞和CD34^＋CD38-干细胞,利用微量细胞RQ—PCR方法检测分选细胞中5个基因的表达。结果表明：NBMMNC均表达这5个基因,其中irf-1与dapk表达水平最高,相对表达量分别为4．08和3．86;abca5和mdr-1表达水平较低,为0．49和0．84;kdr表达最低为0．02。在经分选的CD34^＋CD38^＋祖细胞中,dapk和irf-1表达明显减低（P〈0．05）,kdr表达明显增加（P〈0．05）,其余2个基因无明显变化。在CD34^＋CD38^＋Lin-干细胞中,5个基因的表达均高于CD34^＋CD38^＋祖细胞,普遍增加至近2倍,而kdr增加了3倍,其中kdr和irf-l表达的增加具有统计学差异（P〈0．05）。与NBM相比,AMLMNC中5个基因的表达水平均有不同程度减低,以abca5、mdr-1、kdr和dapk最为显著（P〈0．05）。与AMLMNC相比,AMLCD34^＋CD38^＋细胞中,irf-1和dapk表达明显减低（P〈0．05）,其余3个基因表达增加,以kdr表达增加有统计学意义（P〈0．05）。AMLCD34^＋CD38^＋与CD34^＋CD38^-细胞比较,发现5个基因在CD34^＋CD38^＋细胞中的表达均增加,尤以kdr和irf-1的表达增加有意义（P〈0．05）。AMLCD34^＋CD38^＋CD7^＋细胞与CD34^＋CD38^-CD7-细胞中5个基因的表达均比CD34^＋CD38^＋细胞中的高,其中只有CD34^＋CD38^- CD7^＋细胞中KDR和CD34^＋CD38^-CD7^-细胞中KDR和irf-1的表达增加并具有统计学差异（P〈0．05）。结论：NBM中kdr主要表达在干／祖细胞中,而dapk和irf-1主要表达在较分化的细胞中。5个基因在干细胞阶段的表达均高于祖细胞阶段。AMLCD34^＋CD38^-CD7^＋细胞与CD34^＋CD38^＋CD7^-都具有干／祖细胞的基因表达特点。     

四色流式细胞术分析B细胞型急性淋巴细胞白血病免疫表型

为了研究国人B细胞型急性淋巴细胞白血病(B-ALL)免疫表型特点，使用了四色流式细胞术CD45／SSC 设门分析181例B-ALL的免疫表型。研究结果发现，所有检测病例CDl9阳性率100％，HLA-DR阳性率98．9％，CD38，CD10和CD34阳性率分别为88．5％，76．8％和76．8％，CD117与T系抗原CD2和CD7在B-ALL中很少表达。儿童组(≤14岁)CD10比例较高，青少年(15-18岁)和成人组(≥19岁)髓系相关抗原CD13和(或)CD33表达较高。各年龄组CD10 ／CD34 型比例最高，随年龄增长CD10 /CD34 型比例升高。CD10-CD34 型伴殖系抗原表达率明显高于其它亚型。与CD45 病例相比，CD45-或CD45 /-病例常伴有较高的CD10表达。43例标本RT-PCR检测bcr／abl结果显示：bcr／abl 组和bcr／abl-组伴殖系抗原表达率无显性差弄，m-bcr／abl 主要见于CD10／CD34 型。结论：典型的B-ALL细胞表达CD19和HLA-DR，不表达CD117。不同发育阶段CD34，CD10和CD45表达不一。青少年组免疫表型与成人组相似。CD45 多见于CD10-B-ALL。儿童组殖系抗原表达率较低。m-bcr／abl 多见于CD10／C1)34 型B-ALL。     

CD34 expression in native human acute myelogenous leukemia blasts: differences in CD34 membrane molecule expression are associated with different gene expression profiles

BACKGROUND: The stem cell marker CD34 is expressed by leukemia blasts only for a subset of patients with acute myelogenous leukemia (AML). It is still controversial as to whether CD34 expression (defined as at least 10-20% positive cells) has any prognostic effect in patients with AML who receive intensive chemotherapy. The present study investigated whether gene expression profiling could be used to further subclassify CD34(+) AML cell populations. METHODS: AML blasts derived from 25 patients were examined; these patients were randomly selected from a larger consecutive group of patients. CD34 protein expression was determined by flow cytometry and expressed as the percentage of positive cells. Gene expression profiles were determined by complementary DNA microarrays. RESULTS: By unsupervised hierarchical clustering our patients could be grouped into two or three major subsets depending on the methodologic approach before clustering analysis (filtering or flooring of data, respectively). However, both approaches identified a cluster characterized by high gene expression and membrane molecule level of CD34. When using the floored expression profiles, the patient cluster characterized by increased CD34 gene expression was also characterized by a high percentage of CD34(+) cells (median 82%, range 56-100%) compared with the two other major clusters (median 19%, range <1-55%), but three of four outpatients also showed a high percentage of CD34(+) cells. CONCLUSION: A major proportion of patients with AML and high CD34 expression (usually >80% CD34(+) cells; nearly all patients had >50% positive cells) showed similarities in gene expression profile. In contrast, patients with lower CD34 expression often had a profile similar to those of patients regarded as CD34(-) according to conventional criteria. Our results suggest that the possible prognostic effect of CD34 expression should be reevaluated in clinical studies using additional or alternative cutoff values to describe CD34 expression.     

CD7和(或)CD56阳性急性髓系白血病患者干细胞表型分析及在微量残留病检测中的意义

目的 探讨CD7和(或)CD56阳性急性髓系白血病(AML)干细胞免疫表型特点及微量残留病(MRD)与白血病干细胞LSC的关系.方法 采用四色流式细胞术,以4～6组四色抗体组合检测51例CD7+和(或)CD56+及CD34+CD38+初治AML患者(除外M3)白血病细胞免疫表型,并检测CD34+CD38-Lin-LSC中CD123、CD90、CD117、CD7和CD56的表达.以28名正常人骨髓作为对照,以CD34+CD38+细胞同时表达CD7和CD56作为白血病细胞标志,对26例CD7+和(或)CD56+AML患者的53份标本进行MRD监测.结果 CD7+和(或)CD56+初治AML患者CD34+CD38+细胞和CD34+CD38-Lin-干细胞中,CD7+细胞相对比例分别为(77.39±20.71)%,(44.57±22.70)%,CD56+细胞分别为(56.71±32.56)%,(33.51±29.64)%,均明显高于正常对照(P＜0.01和P＜0.05).CD34+CD38-Lin-干细胞中低表达CD90(P＜0.01),高表达CD123(P＜0.01);CD117的表达和正常对照相比差异无统计学意义(P＞0.05).在随访的CD7+和(或)CD56+患者中,MRD阳性组CD34+CD38-Lin-亚群中CD7和(或)CD56表达的相对比例和实际比例增高的患者比例明显高于MRD阴性组,CD7+细胞实际比例增高的患者分别为71%(21例中15例)与16%(25例中4例)(P=0.001),相对比例增高的患者分别为81%(21例中17例)与24%(25例中6例)(P=0.000).CD56+细胞实际比例增高的患者分别为100%(4例)与12%(25例中3例)(P=0.001),相对比例增高的患者分别为75%(4例中3例)与20%(25例中5例)(P=0.031).CD7+AML患者中初治时CD7+CD34+CD38-Lin-细胞亚群实际比例高的患者治疗后较易出现MRD(P＜0.05).结论 CD7和CD56在AML患者的异常表达发生在AML细胞分化的早期阶段,治疗后CD34+CD38-Lin-干细胞中CD7+和CD56+细胞比例高的患者易出现MRD.     

ZAP-70 expression is low in normal precursor B cells or hematogones

BACKGROUND: Zeta-associated protein (ZAP-70) expression has been associated with a less favorable prognosis in chronic lymphocytic leukemia (CLL). The role of ZAP-70 in immature B-cells is not well understood. Immature or precursor B lymphocytes (hematogones) often occur in clinical samples and coexpress CD10, CD38, and CD19 lacking surface immunoglobulin expression. The present study was carried out in an attempt to further elucidate the role of ZAP-70 in the spectrum of B-cells seen in clinical specimens. METHODS: ZAP-70 expression was evaluated on 25 patient samples that expressed greater than 2% of CD10(+)/CD38(bright)/CD19(+) coexpression during routine evaluation. In our sample set, the hematogone expression ranged from 2 to 18% of total leukocytes and occurred in a variety of conditions, including CLL, NHL, AML, MDS, Hodgkins Disease, and Multiple Myeloma. The method of ZAP-70 detection was that routinely applied to our clinical testing of CLL samples supplemented with the determination of ZAP-70 levels in the CD38(bright)/CD19(+) coexpressing cells. RESULTS: In all cases ZAP-70 was not expressed on the CD5 negative, CD38/CD19 coexpressing precusor B cells. In all cases hematogones were found to not express significant levels of ZAP-70. CONCLUSION: The presence of hematogones in clinical samples should be recognized so as to not adversely influence prognostic studies of ZAP-70 or CD38 in CLL.     

Increased immature hematopoietic progenitor cells CD34+/CD38dim in myelodysplasia

BACKGROUND: Myelodysplastic syndromes (MDS) are clonal disorders affecting hematopoietic progenitor cells (HPC). Despite the relevance of clonal CD34+ cells in developing MDS, only few studies analyze the phenotype of this cell population. The aim of this study was to evaluate phenotypic changes on HPC in MDS that could reflect abnormalities in the differentiation process of stem cells. METHODS: We analyzed the expression of CD38 and HLA-DR on CD34+ cells by flow cytometry in 36 patients with MDS, as well as in healthy donors (n = 12) and patients with other hematological disorders: non-Hodgkin lymphomas and multiple myeloma, both in complete remission (CR) (n = 32); acute lymphoblastic leukemia in CR (n = 17); de novo acute myeloblastic leukemia (AML) at diagnosis (n = 22) and in CR (n = 37); and AML secondary to MDS at diagnosis (n = 19). Cases with available karyotype were grouped according to the International Prognostic Scoring System (IPSS). RESULTS: Compared to normal BM, the fraction of immature HPC, characterized as CD34+bright, intermediate FSC/SSC, and CD38dim, was significantly increased in high risk MDS and secondary AML, but not in low risk MDS, (P < or = 0.001, P = 0.03, and P = 0.7). De novo AML showed decreased immature HPC. High numbers of immature HPC correlated with higher IPSS risk groups (P = 0.05) and showed significant impact on disease progression (P = 0.03). CONCLUSION: Our study confirms that evaluation of CD38 expression pattern on HPC is an easy and reproducible test that allows evaluating the immature subset of progenitor cells. Increased immature HPC in high risk MDS and secondary AML may reflect blocked differentiation of CD34+ cells in these diseases.     

Quiescent subpopulations of human CD34-positive hematopoietic stem cells are preferred targets for stable recombinant adeno-associated virus type 2 transduction

We have previously demonstrated recombinant adeno-associated viral (rAAV) transduction of human CD34(+) hematopoietic stem cells (HSCs) capable of serial engraftment in vivo. Here we evaluated the capacity of rAAV2 to mediate gene transfer into nondividing, quiescent, primitive CD34(+) cells subdivided on the basis of metabolic, mitotic, and phenotypic properties. Results revealed that CD34(+)CD38() marrow cells are the most quiescent, exist primarily in G(0) at isolation and are the only population to remain nondividing during the entire exposure to free rAAV. Despite significant differences in the extended clonogenic capacities of CD34(+) subsets in stromal cultures, the frequency of rAAV marking of colonies derived from primitive progenitors was similar in all three populations, suggesting that both primitive and more differentiated progenitors were initially transduced at equal levels. After transduction, episomal and integrated rAAV genomes were detected in all CD34(+) subsets. However, the more quiescent cells displayed higher levels of integrated rAAV than did rapidly dividing cells. Importantly, stable long-term integration was observed only in the most primitive, quiescent CD34(+)CD38(-) subset, indicating that this HSC compartment comprises the preferred substrate for stable rAAV2 transduction. Previously described rate limitations to transgene expression were observed in transduced CD34(+) cells and could be overcome by tyrphostin pretreatment, which resulted in augmented second-strand synthesis. These results represent the first demonstration of rAAV-mediated gene transfer to primitive, quiescent human CD34(+)CD38(-) stem cells and reveal that nondividing CD34(+)CD38(-) HSCs are the optimal CD34(+) targets for rAAV transduction.     

c-MPL在急性髓系白血病患者白血病干细胞中的表达

本研究通过检测c-MPL在急性髓系白血病(AML)患者骨髓细胞中的表达,探讨c-MPL表达与CD34、CD38的相关性,以确定c-MPL在白血病干细胞的表达。通过流式细胞术检测29例初诊AML患者的c-MPL和CD34、CD38阳性细胞比例;比较患者c-MPL表达水平与正常对照的差别及与临床指标的关系;分析患者的c-MPL表达水平与CD34、CD38各部分细胞分群的关系及它们之间的相关性。结果表明:AML患者骨髓细胞中c-MPL表达水平显著高于正常对照组(P<0.05);c-MPL的表达与患者的年龄、性别、白细胞计数、AML1-ETO融合基因、化疗后缓解情况无关;c-MPL在M2和M5分型中的表达显著高于正常对照组(P<0.05)。CD34阳性AML患者组的c-MPL表达水平显著高于CD34阴性AML患者组(P<0.01)。AML患者c-MPL在CD34+细胞中的表达显著高于CD34-细胞(P<0.001);AML患者中c-MPL在CD34+CD38+和CD34+CD38-两群细胞中的表达无显著性差异(P>0.05);c-MPL和CD34的表达呈正相关(r=0.380,P=0.042)。结论:c-MPL在AML患者中高表达,且与CD34的表达水平具有一定的正相关性,c-MPL表达于白血病干细胞。     

免疫球蛋白重链胚系基因Cβ在白血病中的异常表达

目的：探讨ＩｇＨ胚系Ｃμ基因表达白血病发病中的意义。方法：应用逆转录－聚合酶链反应对各型急，慢性白血病５９例６３份骨髓标本进行免疫球蛋白重链（ＩｇＨ）胚系Ｃμ基因转录本检测。结果：在多种急，慢性白血病亚型中均可以检出胚系Ｃμ链基因的转录。在急性髓系白血病（ＡＭＬ）和急性淋巴细胞白血病（ＡＬＬ）中分别为６５．４％和７５．０％，而慢性粒细胞白血病变期４例和慢性淋巴细胞白血病２例均呈阳性，ＩｇＨ胚系基因     

Preincubation with endothelial cell monolayers increases gene transfer efficiency into human bone marrow CD34(+)CD38(-) progenitor cells

Retroviral gene transfer studies targeting bone marrow CD34(+)CD38(-) stem cells have been disappointing because of the rarity of these cells, their G(0) cell cycle status, and their low or absent expression of surface retroviral receptors. In this study, we examined whether preincubation of bone marrow CD34(+)CD38(-) stem cells with a hematopoietically supportive porcine microvascular endothelial cell line (PMVECs) could impact the cell cycle status and expression of retroviral receptors in pluripotent CD34+CD38- cells and the efficiency of gene transfer into these primitive target cells. PMVEC coculture supplemented with GM-CSF + IL-3 + IL-6 + SCF + Flt-3 ligand induced >93% of the CD34(+)CD38(-) population to enter the G(1) or G(2)/S/M phase while increasing this population from 1.4% on day 0 to 6.5% of the total population by day 5. Liquid cultures supplemented with the identical cytokines induced 73% of the CD34(+)CD38(-) population into cell cycle but did not maintain cells with the CD34(+)CD38(-) phenotype over time. We found no significant increase in the levels of AmphoR or GaLVR mRNA in PMVEC-expanded CD34(+)CD38(-) cells after coculture. Despite this, the efficiency of gene transfer using either amphotropic vector (PA317) or GaLV vector (PG13) was significantly greater in PMVEC-expanded CD34(+)CD38(-) cells (11.4 +/- 5.6 and 10.9 +/- 5.2%, respectively) than in either steady state bone marrow CD34(+)CD38(-) cells (0.6 +/- 1.7 and 0.2 +/- 0.6%, respectively; p < 0.01 and p < 0.01) or liquid culture-expanded CD34(+)CD38(-) cells (1.4 +/- 3.5 and 0.0%, respectively; p < 0.01 and p < 0.01). Since PMVEC coculture induces a high level of cell cycling in human bone marrow CD34(+)CD38(-) cells and expands hematopoietic cells capable of in vivo repopulation, this system offers potential advantages for application in clinical gene therapy protocols.     

急性髓系白血病患者白血病干细胞WT1基因表达水平及其临床意义

目的 探讨急性髓系白血病(AML)患者WT1基因高表达是否发生在白血病干细胞(LSC)阶段及其意义.方法 采用流式细胞术分选AML患者CD34~+ CD38~- CD123~+细胞,实时荧光定量RT-PCR方法 检测其总WT1、+17AA、+KTS异构体的表达,计算出WT1(+/+)、wT1(+/-)、WT1(-/+)、WT1(-/-)四种异构体的比例,并与来源于正常人和AML患者骨髓的CD34~+ CD38~- CD123~-干细胞比较;同时分析AML患者LSC WT1表达水平与缓解率、生存期的关系.结果 AML患者骨髓CD34~+CD38~-CD123~+细胞WT1相对表达水平最高(0.034±0.034),AML患者骨髓CD34~+CD38~-CD123~-细胞群表达次之,来源于正常人的骨髓CD34~+ CD38~- CD123~- 细胞表达最低,三组之间比较差异有统计学意义(P<0.05);三群细胞中均以+17AA为主,组间比较差异无统计学意义.+KTS异构体比例在正常干细胞中最高,为0.57±0.04,在AML患者CD34~+ CD38~- CD123~- 细胞群中所占比例最低,为0.50±0.12,两组比较差异有统计学意义(P<0.05);三种细胞群中四种异构体的表达比例各组之间比较差异无统计学意义(P>0.05),均以WT1(+/+)为主,WT1(-/-)最少.CD34~+ CD38~- CD123~+ LSC中WT1表达水平与患者性别、年龄、FAB分型及骨髓中原始细胞比例无明显相关性,但AML患者WT1高表达组原始细胞群CD34~+ 细胞比例明显高于WT1低表达组(P<0.01).WT1高表达组患者CR率为21.1%,低表达组CR率为59.1%,差异有统计学意义(P<0.05).对41例患者跟踪随访118(3-290)d,WT1 mRNA高表达组中位生存时间77[95%可信区间(CI)45-108]d,较低表达组中位生存时间158(95% CI 100-215)d短,差异有统计学意义(P= 0.041).结论 AML患者WT1高表达发生于LSC阶段,其异构体比例与正常干细胞比较差异无统计学意义.干细胞阶段WT1高表达常导致患者缓解率低、生存期短.     

Human acute myelogenous leukemia stem cells are rare and heterogeneous when assayed in NOD/SCID/IL2Rγc-deficient mice

Human leukemic stem cells, like other cancer stem cells, are hypothesized to be rare, capable of incomplete differentiation, and restricted to a phenotype associated with early hematopoietic progenitors or stem cells. However, recent work in other types of tumors has challenged the cancer stem cell model. Using a robust model of xenotransplantation based on NOD/SCID/IL2Rγc-deficient mice, we confirmed that human leukemic stem cells, functionally defined by us as SCID leukemia-initiating cells (SL-ICs), are rare in acute myelogenous leukemia (AML). In contrast to previous results, SL-ICs were found among cells expressing lineage markers (i.e., among Lin+ cells), CD38, or CD45RA, all markers associated with normal committed progenitors. Remarkably, each engrafting fraction consistently recapitulated the original phenotypic diversity of the primary AML specimen and contained self-renewing leukemic stem cells, as demonstrated by secondary transplants. While SL-ICs were enriched in the Lin-CD38- fraction compared with the other fractions analyzed, SL-ICs in this fraction represented only one-third of all SL-ICs present in the unfractionated specimen. These results indicate that human AML stem cells are rare and enriched but not restricted to the phenotype associated with normal primitive hematopoietic cells. These results suggest a plasticity of the cancer stem cell phenotype that we believe has not been previously described.     

Transplantable hematopoietic stem cells in human fetal liver have a CD34(+) side population (SP)phenotype

Cells with a verapamil-sensitive ability to efflux Hoechst 33342 (termed side population [SP] cells) have been identified in adult marrow from several species including humans and in several tissues from adult mice. In mice, the SP phenotype appears to be a common feature of stem cells, but human SP cells have been less well characterized. We show here, for the first time to our knowledge, that SP cells are present in the second-trimester human fetal liver. They include all of the transplantable human hematopoietic stem cell activity detectable in NOD/SCID mice and also certain other, more differentiated hematopoietic cell types. Notably, the stem cell activity was confined to the CD34(+)CD38(-) SP(+) population, and isolation of these cells gave an approximately tenfold enrichment of transplantable stem cells. This subset was not, however, coenriched in hematopoietic progenitors detectable by either short- or long-term in vitro assays, indicating most of these to be distinct from transplantable stem cells. These findings suggest that the SP phenotype is an important and distinguishing property of human hematopoietic stem cells and that early in ontogeny they express CD34.     

Successful transduction of human multipotent, lymphoid (T, B, NK) and myeloid, and transplantable CD34+CD38low cord blood cells using a murine oncoretroviral vector

Hematopoietic stem cells (HSC) are subject to great interest because of their medical importance and their biological properties. Therefore, the possibility of genetically modifying human HSC is a major concern in several inherited pathologies. In this study, we aimed to demonstrate that a murine oncoretroviral vector can transduce multipotential cord blood (CB) stem cells. Sorted CB CD34(+)CD38(low) cells were transduced with a Moloney-based MFG retroviral vector containing the coding sequence of the murine CD2 (mCD2). CD34(+)mCD2(+) cells were sorted by flow cytometry and cultured either in bulk or at one cell per well in culture conditions that allow differentiation along lymphoid (T, B, and NK) and myeloid (M) lineages. Phenotypic analysis of cells generated in culture showed that CD34(+)mCD2(+) cells could give rise to all lymphoid and myeloid progeny, indicating that the MFG/mCD2 vector had transduced progenitors of all tested lineages. Moreover, clonal cultures of 660 CD34(+)mCD2(+) cells showed that approximately 5% of these cells were able to generate both myeloid and lymphoid (B + NK) progenies; for 25% of them, this included the production of lymphoid T cells. We also demonstrate that transduced CD34(+)CD38(low) CB cells with lymphoid and myeloid potentials were capable of engraftment into the bone marrow (BM) of nonobese diabetic-severe combined immunodeficiency (NOD-SCID) mice during several months. These results show that MFG retroviral vectors can transduce multipotent (T, B, NK, M) human hematopoietic progenitors with in vivo repopulating activity.     

Tpo、IL-11基因修饰的基质细胞对CD34+CD38-早期造血祖细胞扩增的影响

目的　观察经Tpo、IL 11基因修饰的基质细胞对脐血CD3 4 + CD3 8-细胞体外扩增的影响。方法　用载有Tpo、IL 11基因的重组逆转录病毒感染成纤维样基质细胞HFCL ,通过Northernblot法检测基因修饰的HFCL细胞Tpo、IL 11基因的表达。以未经基因修饰的HFCL细胞作为对照 ,将脐血CD3 4 + 造血干 /祖细胞在这种基因修饰的HFCL细胞支持下 ,进行 7d体外扩增后 ,用锥虫蓝拒染法计数活细胞总数 ,并用流式细胞仪分析扩增细胞中CD3 4 + 细胞以及CD3 4 + CD3 8-细胞的比例。结果　在Tpo基因修饰的HFCL细胞、IL 11基因修饰的HFCL细胞和Tpo +IL 11基因共同修饰的HFCL细胞的支持下 ,扩增后CD3 4 + CD3 8-早期造血祖细胞的比例分别为 (1.8± 0 .2 4 ) %、(1.6 2± 0 .2 3) %、(2 .4 5±0 2 8) % ,细胞扩增倍数为 4 .2倍、3.6倍、6 .9倍 ,高于对照组的 (0 .80± 0 .2 3) %和 1.5倍 ,同时扩增细胞总数和CD3 4 + 细胞比例亦高于未经基因修饰的HFCL细胞所支持的扩增体系。结论　Tpo、IL 11基因修饰的基质细胞可有效促进脐血CD3 4 + 造血干 /祖细胞体外扩增 ,同时能有效维持扩增体系中的CD3 4 + CD3 8-细胞以及促进其扩增。     

Mobilized blood CD34+ cells transduced and selected with a clinically applicable protocol reconstitute lymphopoiesis in SCID-Hu mice

We developed a clinically applicable gene transfer procedure into mobilized peripheral blood (MPB) CD34(+) hematopoietic progenitor cells, based on single viral exposure and selection of engineered cells. CD34(+) cells were transduced with a retroviral vector carrying the truncated form of the nerve growth factor receptor (Delta NGFR) marker gene, and immunoselected for Delta NGFR expression. Optimal time and procedure for viral exposure, length of culture, and transgene expression of MPB CD34(+) cells were determined using in vitro assays. The multipotent capacity of MPB CD34(+)-transduced cells was demonstrated in the SCID-hu bone/liver/thymus mouse model. Transduced Delta NGFR(+) cells retained 50% of long-term culture-colony forming cells (LTC-CFC) compared to unmanipulated CD34(+) cells. In SCID-hu mice, 52% of CD45(+) cells, 27% of CD34(+) cells, 49% of B cells, and more than 50% of T cells were derived from transplanted CD34(+)/Delta NGFR(+) cells. Furthermore, transplantation of purified transduced cells greatly reduced the competition with untransduced progenitors occurring in unselected grafts. These data demonstrate that MPB CD34(+) cells, transduced with a single viral exposure and selected by transgene expression, retain multilineage reconstitution capacity and remarkable transgene expression.     

真性红细胞增多症患者骨髓CD34阳性细胞凋亡相关蛋白的表达

目的　了解真性红细胞增多症 (PV)患者骨髓CD34 细胞凋亡受体FAS(CD95 )及凋亡相关蛋白Bcl 2、Bax的表达。方法　应用双色流式细胞仪检测 2 1例PV患者及 8例原发性血小板增多症(ET)患者和 11名正常人骨髓CD34 细胞CD95、Bcl 2、Bax的表达 ;应用RT PCR方法检查PV患者及对照组骨髓造血细胞Bcl 2、BaxmRNA的表达情况并分析其相关性。结果　CD34 细胞CD95表达率PV患者为 (4 2 .6 5± 15 .5 6 ) % ,ET患者为 (4 5 .31± 17.6 2 ) % ,与正常对照组的 (37.5 5± 15 .19) %差异无显著性 (P >0 .0 5 ) ;Bax表达率PV患者为 (35 .83± 9.33) % ,与正常对照组的 (4 1.6 5± 9.0 4 ) %差异无显著性(P >0 .0 5 ) ;Bcl 2表达率PV患者为 (79.35± 14 .4 3) % ,明显高于正常对照组的 (5 5 .84± 13.4 3) % ,(P <0 .0 1) ;Bax/Bcl 2的比值PV患者为 0 .4 7± 0 .14 ,明显低于正常对照组的 0 .76± 0 .2 4 (P <0 .0 1) ;骨髓造血细胞Bcl 2mRNA的表达PV患者明显高于正常对照组 (P <0 .0 1) ,BaxmRNA的表达PV患者与正常对照组差异无显著性 (P >0 .0 5 )。PV患者CD34 细胞Bcl 2高表达与CD34 细胞的凋亡呈负相关 (r=- 0 .4 97,P =0 .0 2 6 )。结论　PV患者骨髓CD34 细胞低凋亡的机制之一是抗凋亡蛋白Bcl 2高表达     

Ligation of CD38 suppresses human B lymphopoiesis

CD38 is a transmembrane glycoprotein expressed in many cell types, including lymphoid progenitors and activated lymphocytes. High levels of CD38 expression on immature lymphoid cells suggest its role in the regulation of cell growth and differentiation, but there is no evidence demonstrating a functional activity of CD38 on these cells. We used stroma-supported cultures of B cell progenitors and anti-CD38 monoclonal antibodies (T16 and IB4) to study CD38 function. In cultures of normal bone marrow CD19+ cells (n = 5), addition of anti-CD38 markedly reduced the number of cells recovered after 7 d. Cell loss was greatest among CD19+ sIg- B cell progenitors (mean cell recovery +/- SD = 7.2 +/- 11.7% of recovery in control cultures) and extended to CD19+CD34+ B cells (the most immature subset; 7.6 +/- 2.2%). In contrast, CD38 ligation did not substantially affect cell numbers in cultures of normal peripheral blood or tonsillar B cells. In stroma- supported cultures of 22 B-lineage acute lymphoblastic leukemia cases, anti-CD38 suppressed recovery of CD19+ sIg- leukemic cells. CD38 ligation also suppressed the growth of immature lymphoid cell lines cultured on stroma and, in some cases, in the presence of stroma- derived cytokines (interleukin [IL] 7, IL-3, and/or stem cell factor), but did not inhibit growth in stroma- or cytokine-free cultures. DNA content and DNA fragmentation studies showed that CD38 ligation of stroma-supported cells resulted in both inhibition of DNA synthesis and induction of apoptosis. It is known that CD38 catalyzes nicotinamide adenine dinucleotide (NAD+) hydrolysis into cyclic ADP-ribose (cADPR) and ADPR. However, no changes in NAD+ hydrolysis or cADPR and ADPR production after CD38 ligation were found by high-performance liquid chromatography; addition of NAD+, ADPR, or cADPR to cultures of lymphoid progenitors did not offset the inhibitory effects of anti- CD38. Thus, anti-CD38 does not suppress B lymphopoiesis by altering the enzymatic function of the molecule. In conclusion, these data show that CD38 ligation inhibits the growth of immature B lymphoid cells in the bone marrow microenvironment, and suggest that CD38 interaction with a putative ligand represents a novel regulatory mechanism of B lymphopoiesis.