HUMAN PRIMITIVE HEMATOPOIETIC PROGENITOR CELLS ARE MORE ENRICHED IN CD34^+CD38^- POPULATION THAN IN CD34^+CD38^+ POPULATION

To clarify the hematopoietic potential of various sub-classes of human hematopoietic progenitor cells, we used a multicolor staining protocol in conjunction with anti-CD34 and -CD38 McAb. We characterized two cell fractions in CD34+cells with or without CD38 expression. A clonogenic assay showed that most CFC were present in CD34+CD38+ population. Morphologic analysis showed that blast-like cells were more enriched in the CD34+CD38 fraction. To clarify the biologic differences between both fractions, we examined the more primitive progenitor cell function by assessing long-term culture-initiating cells (LTC-IC) on the stromal cells. At the first two weeks, more CF.C harvested from the culture in the fractions initiated with both populations. However, more LTC-IC were present during weeks 4 to 12 in the CD34+CD38- population. These results indicate the primitive progenitors are more enriched in CD34+CD38 population than in CD34+CD38+ cells.

Hematopoietic stem cells in research and clinical applications:The“CD34 issue”

In this paper,experimental findings concerning the kinetics of hematopoietic reconstitution are compared to corresponding clinical data.Although not clearly apparent,the transplantation practice seems to confirm the basic proposals of experimental hematology concerning hematopoietic reconstitution resulting from successive waves of repopulation stemming from different subpopulations of progenitor and stem cells.One of the "f irst rate" parameters in clinical transplantations in hematology;i.e.the CD34+ positive cell dose,has been discussed with respect to the functional heterogeneity and variability of cell populations endowed by expression of CD34.This parameter is useful only if the relative proportion of stem and progenitor cells in the CD34+ cell population is more or less maintained in a series of patients or donors.This proportion could vary with respect to the source,pathology,treatment,processing procedure,the graft ex vivo treatment and so on.Therefore,a universal dose of CD34+ cells cannot be def ined.In addition,to avoid further confusion,the CD34+ cells should not be named "stem cells" or "progenitor cells" since these denominations only concern functionally characterized cell entities.

Impact of T cells on hematopoietic stem and progenitor cell function:Good guys or bad guys?

When hematopoietic stem and progenitor cells(HSPC)are harvested for transplantation, either from the bone marrow or from mobilized blood, the graft contains a significant number of T cells. It is these T cells that are the major drivers of graft-vs-host disease(Gv HD). The risk for Gv HD can simply be reduced by the removal of these T cells from the graft. However, this is not always desirable, as this procedure also decreases the engraftment of the transplanted HSPCs and, if applicable, a graft-vs-tumor effect. This poses an important conundrum in the field: T cells act as a double-edged sword upon allogeneic HSPC transplantation, as they support engraftment of HSPCs and provide anti-tumor activity, but can also cause Gv HD. It has recently been suggested that T cells also enhance the engraftment of autologous HSPCs, thus supporting the notion that T cells and HSPCs have an important functional interaction that is highly beneficial, in particular during transplantation. The underlying reason on why and how T cells contribute to HSPC engraftment is still poorly understood. Therefore, we evaluate in this review the studies that have examined the role of T cells during HSPC transplantation and the possible mechanisms involved in their supporting function. Understanding the underlying cellular and molecular mechanisms can provide new insight into improving HSPC engraftment and thus lower the number of HSPCs required during transplantation. Moreover, it could provide new avenues to limit the development of severe Gv HD, thus making HSPC transplantations more efficient and ultimately safer.

Exploring hematopoietic stem cell population in human milk and its benefits for infants:A scoping review

Objective:To comprehensively explore hematopoietic stem cells(HSCs)in human milk,understanding their molecular markers,isolation methods,benefits for infants,and potential medical applications.Methods:We conducted a scoping literature review following the PRISMA-ScR guidelines.This review included studies investigating HSCs in human milk,utilizing molecular markers such as CD34^(+),CD113^(+),and CD117^(+)for characterization.Both in vitro and in vivo studies exploring the morphology,function,and clinical implications of these cells were considered.The diverse range of papers reviewed were indexed in PubMed,Science Direct,Scopus,Sage Journals,and Google Scholar,published between 2010 and 2023.Results:This scoping review explored 577 articles and selected 13 studies based on our inclusion criteria,focusing on HSCs in human milk.Most studies dilute samples prior to HSC isolation,followed by detection using markers such as CD34^(+),CD113^(+),and CD117^(+),with flow cytometry serving as the primary analysis tool,focusing on their isolation and detection methods.While no definitive benefits have been conclusively established,there is a strong belief in the potential of HSCs to positively impact infant immunity,growth,and tissue repair.Conclusions:This review presents significant evidence supporting the presence of HSCs in human milk,identified by markers such as CD34^(+),CD113^(+),and CD117^(+).These cells show considerable potential in enhancing infant health,including immunity,tissue repair,cognitive development,and gastrointestinal health.Despite methodological variations in isolation and detection techniques,the collective findings underscore the potential clinical relevance of HSCs in human milk.Moreover,this review highlights the noninvasive accessibility of human milk as a source of HSCs and emphasizes the need for further research to unlock their therapeutic potential.

A familiar stranger:CD34 expression and putative functions in SVF cells of adipose tissue

Human adipose tissue obtained by liposuction is easily accessible and an abundant potential source of autologous cells for regenerative medicine applications. After digestion of the tissue and removal of differentiated adipocytes, the so-called stromal vascular fraction (SVF) of adipose, a mix of various cell types, is obtained. SVF contains mesenchymal fibroblastic cells, able to adhere to culture plastic and to generate large colonies in vitro , that closely resemble bone marrow-derived colony forming units-fibroblastic, and whose expanded progeny, adipose mesenchymal stem/stromal cells (ASC), show strong similarities with bone marrow mesenchymal stem cells. The sialomucin CD34, which is well known as a hematopoietic stem cell marker, is also expressed by ASC in native adipose tissue but its expression is gradually lost upon standard ASC expansion in vitro . Surprisingly little is known about the functional role of CD34 in the biology and tissue forming capacity of SVF cells and ASC. The present editorial provides a short introduction to the CD34 family of sialomucins and reviews the data from the literature concerning ex- pression and function of these proteins in SVF cells and their in vitro expanded progeny.

Apoptotic bone marrow CD34+ cells in cirrhotic patients

AIM: To access the frequency and level of apoptotic CD34+ cells isolated from the marrow fluid of patients with post-hepatitis cirrhosis. METHODS: The frequency of bone marrow CD34+ cells and apoptotic bone marrow CD34+ cells in 31 inpatients with post-hepatitis cirrhosis (cirrhosis group), and 15 out-patients without liver or blood disorders (control group) was calculated by flow cytometry. Parameters were collected to evaluate liver functions of patients in cirrhosis group. RESULTS: The percentage of normal bone marrow CD34+ cells was 6.30% ± 2.48% and 1.87% ± 0.53% (t = 3.906, P < 0.01) while that of apoptotic marrowCD34+ cells was 15.00% ± 15.81% and 5.73% ± 1.57% (t = 2.367, P < 0.05) in cirrhosis and control groups, respectively. The percentage of apoptotic marrow CD34+ cells was 6.25% ± 3.30% and 20.92 ± 18.5% (t = 2.409, P < 0.05) in Child-Pugh A and Child-Pugh B + C cirrhotic patients, respectively. The percentage of late apoptotic marrow CD34+ cells was positively correlated with the total bilirubin and aspartate aminotransferase serum levels in patients with cirrhosis. CONCLUSION: The status of CD34+ marrow cells in cirrhotic patients may suggest that the ability of hematopoietic progenitor cells to transform into mature blood cells is impaired.

Characteristics of Ex Vivo Expansion of Endothelial Progenitor Cells

Summary： The characteristics for the ex vivo expansion of the endothelial progenitor cells （EPCs） were explored, CD34^＋ cells were selected from umbilical cord blood mononuclear cells （MNC） by MiniMACS system, expanded under the same conditions as those for total MNC, coincubation of CD34^＋ and CD34 from the same donor for EPCs. In addition, the effects of vessel endothelial growth factor （VEGF） and passage on cell differentiation, expansion kinetics and apoptosis were examined, EPCs were determined and quantified by immunocytochemistry and flow cytometry, The results showed that both coculture of CD346＋ and CD34^- and total MNC led to a significant increase in the expansion of CD34^＋ cells as compared with CD34 enrichment （P〈0.05）. There was a tendency toward decreased apoptosis in cultures when early passage was performed immediately after cord like structures appeared. VEGF had no significant effect on apoptosis （P〉0.05）, These differentiated EPCs were positive for CD34^＋, von Willebrand factor （vWF）, KDR, CD31 staining and phagocytized acetylated low-density lipoprotein （LDL）. CD34^＋ cells accounted for （68.2±6,3） % of attaching （AT） cells at day 7 of culture. It was suggested the most efficient method to ex vivo expansion of EPCs was coculture of CD34^＋ and CD34^- or total MNC. Early passage makes cell apoptosis rate decrease. VEGF had no significant effect on ex vivo expansion of EPCs.

人造血干/祖细胞多态性的研究:Ⅷ.人正常骨髓 CD34^+造血细胞体视学的特征

人CD34^+造血细胞是具有高度自我更新、多向分化及重建长期造血与免疫学功能的独特体细胞。为系统探索CD34^+造血细胞的形态、细胞化学及超微结构特征,新近我们设计组合并建立了CIMS-100-FACS 440无菌二次分选术,可使所获CD34^+造血细胞的纯度达100%。在此基础上,本研究采用Cambri-dge Quantimet 970全自动图像分析仪对光学显微镜、扫描电镜及透射电镜下的CD34^+造血细胞进行了体视学方面的某些探讨,进一步从三维结构信息中深刻揭示CD34^+造血细胞的形态计量学特征。经扫描→模数转换←阴影校正→图像暂存←统计分析等检测,结果表明:CD34^+造血细胞的直径3.490—6.741μm,周长11.776—26.240μm,面积9.565—35.686μm^2,形状因子1.048—1.840,核浆比0.58—0.72,平均光密度0.17675—0.65100,积分光密度2717.217—9870.643。由此可见CD34^+造血细胞的确为非均一细胞群,这可能与CD34^+造血细胞的功能亚群与分化阶段密切相关。据我们所知,这是国际上首次有关人CD34^+造血细胞体视学特征的报道。

人造血干/祖细胞多态性的研究:Ⅲ.骨髓CD34^+造血干/祖细胞功能亚群的分析

CD 34^+造血干/祖细胞(HSC/HPC)是十分异质性的,由多个不同功能亚群所构成,在分化方向与重建造血等方面差异显著。本文对正常人骨髓CD 34^+ HSC/HPC各亚群进行了较全面的分析。首先以阳性选择策略,采用Isolex^(TM) 50免疫磁球分选术富集骨髓CD 34^+HSC/HPC,其纯度>90%,随之采用免疫荧光抗体双标记二维流式细胞仪对其测定,发现高纯度的CD 34^+HSC/HPC可分为八个不同亚群:1.CD 34^+/CD 71^-(23.4%—56.6%)与CD 34^+/CD 71^+(33.4%—66.6%);2.CD34^+/CD 45^-(80.8%—82.5%)与CD34^+/CD 45^+(8.1%—11.2%);3.CD 34^+/CD 33^-(20.4%—80.6%)与CD 34^+/CD 33^+(14.6%—64.8%);4.CD 34^+/DR^-(6.3%—11.0%)与CD 34^+/DR^+(82.8%—85.5%)。用免疫胶体金——免疫桥酶联组化双染色对上述亚群进一步分析的结果与流式细胞仪的高度一致。

低温冷冻对脐血CD_(34)^+细胞和造血祖细胞增殖的影响

采用－８０℃低温冷冻法，观察冷冻前及冷冻后１、２、３周时单个核细胞（ＭＮＣ）的回收率，脐血造血前体细胞在体外的增殖力，并用流式细胞仪检测ＣＤ３４＋细胞的百分率。旨在探讨低温冷冻对脐血造血前体细胞的影响。结果表明：脐血冷冻后１、２、３周时ＭＮＣ的回收率分别为９３．６％，９１．５％和９０．７％（Ｐ＞０．０５）；细胞活力分别为９８％，９７％，９５％和９１％（Ｐ＞０．０５）；ＣＤ３４＋细胞依次为１．２０％、１．１８％、１．１６％和１．１７％；ＣＦＵ－ＧＭ，ＣＦＵ－Ｅ冷冻后１、２周时回收率达９７％和９５％（Ｐ＞０．０５），第３周时达８９％（Ｐ＞０．０５）。结果提示：长期冷冻可能导致冷冻之脐血祖细胞产率下降，但对代表造血干细胞的ＣＤ３４＋细胞影响则不大。

CD_(34)^+造血干细胞混合CD_3^+ T细胞移植分离移植物抗宿主病和移植物抗白血病效应

目的 探讨在异基因造血干细胞移植中能否采用纯化 CD34 + 造血干细胞混合一定量纯化 CD3+ T细胞移植达到既控制移植物抗宿主病 (GVHD)又保留移植物的抗白血病效应 (GVL )。 方法 (C5 7BL /6× 6 15 ) F1代接种 L 6 15白血病细胞株建立小鼠白血病模型作为移植受鼠 ,利用免疫磁珠纯化骨髓 CD34 + 造血干细胞及脾脏CD3+细胞 ,流式细胞仪分析纯化前后 CD34 +、CD3+细胞百分比 ,观察单纯移植 CD34 +细胞及混合不同数量级 CD3+细胞后受鼠生存时间、GVHD、GVL效应 ,移植后骨髓造血重建细胞来源。 结果 纯化 CD34 + 细胞 1× 10 6 移植组10 0 %死于白血病复发 ;CD34 +细胞 +纯化 CD3+细胞 (1× 10 7)移植组生存期明显延长 ,5 0 %死于白血病复发 ,无GVHD表现 ;CD34 + 细胞 +CD3+ 细胞 (5× 10 7)移植组长期存活 ,无白血病复发 ,无 GVHD表现 ;CD34 + 细胞 +CD3+细胞 (1× 10 8)移植组 6 2 .5 %死于 GVHD,37.5 %长期存活 ;CD34 + 细胞 +CD3+ 细胞 (1.5× 10 8)移植组 10 0 %死于GVHD。移植后生存时间 >6 0 d的受鼠骨髓造血重建细胞 y染色体检出率为 10 0 %。 结论 移植物中 CD3+细胞数量与 GVHD和 GVL效应密切相关 ,通过限定移植物中的 CD3+ 淋巴细胞的含量能够保留

Human umbilical cord mesenchymal stem cells as treatment of adjuvant rheumatoid arthritis in a rat model

AIM:To investigate the effect of human umbilical cord stem cells,both mesenchymal and hematopoietic(CD34+),in the treatment of arthritis.METHODS:Mesenchymal stem cells(MSCs) and hematopoietic(CD34+) stem cells(HSC) were isolated from human umbilical cord blood obtained from the umbilical cord of healthy pregnant donors undergoing fullterm normal vaginal delivery.MSC,HSC,methotrexate(MTX) and sterile saline were injected intra-articularly into the rat hindpaw with complete freunds adjuvant(CFA) induced arthritis after the onset of disease(day 34),when arthritis had become well established(arthritis score ≥ 2).Arthritic indices were evaluated and the levels of interleukin(IL)-1,tumor necrosis factor(TNF)-α and interferon(IFN)-γ and anti-inflammatory cytokine IL-10 in serum were determined using enzyme-linked immunosorbent assay.Animals of all groups were sacrificed 34 d after beginning treatment,except positive control(PC) which was sacrificed at 10,21 and 34 d for microscopic observation of disease progression.We used hematoxylin,eosin and Masson's trichrome stains for histopathological examination of cartilage and synovium.RESULTS:The mean arthritis scores were similar in all groups at 12 and 34 d post immunization,with no statistical significant difference.Upon the injection of stem cells(hematopoietic and mesenchymal),the overall arthritis signs were significantly improved around 21 d after receiving the injection and totally disappeared at day 34 post treatment in MSC group.Mean hindpaw diameter(mm) in the MSC rats was about half that of the PC and MTX groups(P = 0.007 and P = 0.021,respectively) and 0.6 mm less than the HSC group(P = 0.047),as indicated by paw swelling.Associated with these findings,serum levels of TNF-α,IFN-γ and IL-1 decreased significantly in HSC and MSC groups compared to PC and MTX groups(P < 0.05),while the expression of IL-10 was increased.Histopathological examination with H and E stain revealed that the MTX treated group showed significant reduction of leucocytic infiltrate and hypertrophy of the synovial tissue with moderate obliteration of the joint cavity.Stem cells treated groups(both hematopoietic CD34+ and mesenchymal),showed significant reduction in leucocytic infiltrate and hypertrophy of the synovial tissue with mild obliteration of the joint cavity.With Masson's trichrome,stain sections from the PC group showed evidence of vascular edema of almost all vessels within the synovium in nearly all arthritic rats.Vacuoles were also visible in the outer vessel wall.The vessel became hemorrhagic and finally necrotic.In addition,there was extensive fibrosis completely obliterating the joint cavity.The mean color area percentage of collagen in this group was 0.324 ± 0.096,which was significantly increased when compared to the negative control group.The mean color area percentage of collagen in hematopoietic CD34+ and mesenchymal groups was 0.176 ± 0.0137 and 0.174 ± 0.0197 respectively,which showed a marked decrement compared to the PC group,denoting a mild increase in synovial tissue collagen fibers.CONCLUSION:MSC enhance the efficacy of CFAinduced arthritis treatment,most likely through the modulation of the expression of cytokines and amelioration of pathological changes in joints.

Enhancing endothelial progenitor cell for clinical use

Circulating endothelial progenitor cells(EPCs) have been demonstrated to correlate negatively with vascularendothelial dysfunction and cardiovascular risk factors. However, translation of basic research into the clinical practice has been limited by the lack of unambiguous and consistent definitions of EPCs and reduced EPC cell number and function in subjects requiring them for clinical use. This article critically reviews the definition of EPCs based on commonly used protocols, their value as a biomarker of cardiovascular risk factor in subjects with cardiovascular disease, and strategies to enhance EPCs for treatment of ischemic diseases.

Effects of glucocorticoid and cysteinyl leukotriene 1 receptor antagonist on CD_(34)^+ hematopoietic cells in bone marrow of asthmatic mice

BACKGROUND: Corticosteroids remain the most effective therapy available for asthma. They have widespread effects on asthmatic airway inflammation. However, little is known about the effects of corticosteroids on the production of bone marrow inflammatory cells in asthma. This study observed the effects of glucocorticoid and cysteinyl leukotriene 1 receptor antagonist on CD34+ hematopoietic cells, so as to explore the possible effectiveness of a bone marrow-targeted anti-inflammatory strategy. METHODS: Balb/c mice were sensitized and challenged with ovalbumin (OVA) to establish an asthmatic model. For two consecutive weeks, asthmatic mice were challenged with OVA while being given either prednisone, montelukast, prednisone plus montelukast, or sterile saline solution. The mice were killed 24 hours after the last challenge with OVA, and bronchoalveolar lavage fluid (BALF), peripheral blood, and bone marrow were collected. Eosinophils in peripheral blood and BALF, and nucleated cells in BALF, peripheral blood, and bone marrow were counted. The percentages of CD34+ cells, CD4+ T lymphocytes and CD8+ T lymphocytes among nucleated cells in peripheral blood and bone marrow were counted by flow cytometry. Immunocytochemistry and in situ hybridization were employed to detect expression of CD34 and interleukin (IL)-5Ralpha mRNA (CD34+ IL-5Ralpha mRNA+ cells) among bone marrow hematopoietic cells. RESULTS: Compared with the sterile saline solution group, the number of eosinophils in BALF and peripheral blood, CD34+ cells in peripheral blood and bone marrow, and CD34+ IL-5Ralpha mRNA+ cells in bone marrow of mice from the prednisone and prednisone plus montelukast groups were significantly lower (P

Preferential expression of cytochrome CYP CYP2R1 but not CYP1B1 in human cord blood hematopoietic stem and progenitor cells

Cytochrome P450(CYP)enzymes metabolize numerous endogenous substrates,such as retinoids,androgens,estrogens and vitamin D,that can modulate important cellular processes,including proliferation,differentiation and apoptosis.The aim of this study is to characterize the expression of CYP genes in CD34+human cord blood hematopoietic stem and early progenitor cells(CBHSPCs)as a first step toward assessment of the potential biological functions of CYP enzymes in regulating the expansion or differentiation of these cells.CD34+CBHSPCs were purified from umbilical cord blood via antibody affinity chromatography.Purity of CD34+CBHSPCs was assessed using fluorescence-activated cell sorting.RNA was isolated from purified CD34+CBHSPCs and total mononuclear cells(MNCs)for RNA-PCR analysis of CYP expression.Fourteen human CYPs were detected in the initial screening with qualitative RT-PCR in CD34+CBHSPCs.Further quantitative RNA-PCR analysis of the detected CYP transcripts yielded evidence for preferential expression of CYP2R1 in CD34+CBHSPCs relative to MNCs;and for greater expression of CYP1B1 in MNCs relative to CD34+CBHSPCs.These findings provide the basis for further studies on possible functions of CYP2R1 and CYP1B1 in CBHSPCs'proliferation and/or differentiation and their potential utility as targets for drugs designed to modulate CD34+CBHSPC expansion or differentiation.

A bicistronic retroviral vector to introduce drug resistance genes into human umbilical cord blood CD34^+ cells to improve combination chemotherapy tolerance

OBJECTIVE: To study whether human umbilical cord blood CD34+ cells transduced with human aldehyde dehydrogenase class-1 (ALDH-1) and multidrug resistance gene (MDR1) have increases resistance to 4-Hydroperoxycyclo-phosphamide (4-HC) and P-glycoprotein effluxed drugs. METHODS: A bicistronic retroviral vector G1Na-ALDH1-IRES-MDR1 was constructed and used to transfect the packaging cell lines GP + E86 and PA317 by LipofectAMINE method, using the medium containing VCR and 4-HC agents for cloning selection and ping-ponging supernatant infection between the ecotropic producer clone and the amphotropic producer clone, we obtained high titer amphotropic PA317 producing cells with high titers up to 5.6 x 10(5) CFU/ml. Cord blood CD34+ cells were transfected repeatedly with supernatant of retrovirus containing human ALDH-1 and MDR1cDNA under the stimulation of hemopoietic growth factors. RESULTS: Bicistronic retroviral vector construction was verified by restriction endonuclease analysis. Polymerase chain reaction (PCR), reverse transcription (RT)-PCR, Southern blot, Northern blot, fluorescenceactivated cell sorting (FACS) method and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) analyses showed that dual drug resistance genes have been integrated into the genomic DNA of cord blood CD34+ cells and expressed efficiently. The transgenes recipient cells confered 4-fold stronger resistance to 4-HC and 5.5 to 7.2-fold P-glycoprotein effluxed drug than untransduced cells. CONCLUSION: The bicistronic retroviral vector-mediated transfer of two different types of drug resistance genes into human cord blood CD34+ cells and co-expression provided an experimental foundation for improving combination chemotherapy tolerance in tumor clinical trial.

Negative association of donor age with CD34＋ cell dose in mixture allografts of G-CSF-primed bone marrow and G-CSF-mobilized peripheral blood harvests

Background The effects of donor characteristics on CD34＋ cell dose remain controversial. Recently, we developed a novel haploidentical transplant protocol, in which mixture allografts of granulocyte colony-stimulating factor （G-CSF）- primed bone marrow （G-BM） and G-CSF-mobilized peripheral blood （G-PB） were used. The aim of this study was to investigate the effects of donor characteristics on CD34＋ cell dose in mixture allografts of G-BM and G-PB. Methods A total of 162 healthy adult donors, who underwent bone marrow harvest and peripheral blood collection between January 2009 and November 2010 in Peking University People＇s Hospital, were prospectively investigated. G-CSF was administered subcutaneously at a dose of 5 pg/kg once a day for 5-6 consecutive days. Bone marrow and peripheral blood stem cells were harvested on the fourth day and fifth day, respectively. A final total CD34＋ cell dose less than 2× 106 cells/kg recipient body weight was considered a poor mobilization. Results Of the 162 donors, 31 （19.1%） did not attain this threshold. The obtained median CD34＋ cell doses in bone marrow, peripheral blood, and mixture allografts were 0.83×106/kg, 2.40×106/kg, and 3.47×106/kg, respectively. Multiple regression analysis showed that donor age had a significant negative effect on CD34＋ cell dose in either G-BM, or G-PB, or mixture allografts of G-BM and G-PB. And a 1-year increase in age was associated with a 5.6% decrease in the odds of achieving mobilization cutoff. No significant correlation was found for donor gender, body mass index （BMI）, and weight. Conclusion Donor age is the only factor among the four parameters, including age, gender, weight, and BMI, that influence CD34＋ cell dose in mixture allografts of G-BM and G-PB, and younger donors should be chosen to obtain sufficient CD34＋ cells for transplantation.

CD34^＋造血祖细胞的定向诱导分化研究

加强造血调控的基础与临床研究裴雪涛血细胞的生成及其调控涉及生命科学中的许多热点问题，如细胞的增殖、分化、迁移、发育、成熟、衰老、凋亡、癌变，也涉及细胞因子及其受体的相互作用与信号传导，细胞与细胞、细胞与基质的相互作用等。同时，许多血液恶性肿瘤、造血障...

骨髓增生异常综合征患者CD_(34)^+细胞凋亡特征

目的 调查骨髓增生异常综合征 (MDS)造血细胞CD34 抗原表达及CD34 阳性细胞凋亡状况。方法 用免疫酶标记 (碱性磷酸酶 抗碱性磷酸酶系统 ,APAAP)检测 36例MDS患者骨髓冷包埋切片中CD34 阳性细胞数量及分布特征 ,结合DNA原位末端标记技术 (ISEL)研究此类细胞的凋亡状况。14例缺铁性贫血 (IDA)患者作对照。结果 ①MDS组CD34 阳性细胞较对照组明显增多 [分别为 (4 9.2± 38.5 ) mm2 和 (10 .2± 9.7) mm2 ,P <0 .0 1]。MDS组凋亡细胞数与对照组比较也增多 [分别为 (6 9.1±2 8.2 ) mm2 和 (17.8± 11.2 ) mm2 ,P <0 .0 1]。②CD34+ 细胞在MDS RAEB组最高 ,与MDS RA RAS和MDS RAEB t组比较 ,差异有显著性 (P值均 <0 .0 5 ) ,而在后两组间无明显差异 ;MDS RA RAS、RAEB组的细胞凋亡数均明显高于RAEB t组 (P值分别 <0 .0 2和 0 .0 5 )。③ 36例MDS患者中未见CD34 阳性细胞发生凋亡。④CD34 阳性细胞及凋亡细胞均多见于骨小梁间区 ,均有成簇成片状分布的趋势 ,但两类细胞很少分布于同一区域。结论 MDS造血细胞过度表达CD34 抗原 ,MDS转化过程中同时存在CD34阳性细胞和凋亡细胞增加。CD34 阳性细胞的凋亡抵抗现象提示其来自恶性造血克隆。