Aberrant expression of the major sialoglycoprotein (CD43) on the monocytes of patients with myelodysplastic syndromes

 CD43, a sialylated glycoprotein expressed on the surface of most hematopoietic cells, has been implicated in cell adhesion and signaling. The reduced expression of this antigen in patients with WiscottAldrich syndrome, in which progressive immunodeficiency is a major problem, raised the question whether abnormal expression of this molecule could affect the susceptibility to infections in patients with myelodysplastic syndromes (MDS). We studied the expression of this antigen on the monocytes of ten patients with chronic myelomonocytic leukemia (CMML) and compared the results with 67 patients suffering from other MDS syndromes and with 18 healthy individuals. We chose this series as it plays an important role in MDS patients where in most cases the neutrophils are defective. We also examined the following antigens as indicative of activation and adhesion of the monocytes in these patients: CD11b, CD18, CD35, CD38, CD44, CD69. We found decreased expression of CD43 on the monocytes of the RA, RAS, RAEB, and RAEB-t patients compared with the CMML and controls. The other activation molecules studied were found to be upregulated, suggesting the existence of activated monocytes in these patients. The increased levels of soluble vascular cell adhesion molecule in these patients suggest vascular endothelial activation in the absence of infection. Further experiments are needed to investigate the significance of CD43 downregulation in these patients, its role in cell adherence and tissue migration, and the correlation of the phenomenon to the increased susceptibility to infections observed in these patients. Received: 9 April 1999 / Accepted: 21 September 1999     

Alterations of CD43 expression in transfusion-dependent myelodysplastic syndromes

CD43 is a sialylated glycoprotein expressed on the surface of most haemopoietic cells and has been implicated in cell adhesion and signaling. It has previously been shown that CD43 expression is altered in patients with myelodysplastic syndrome (MDS). This raised the question of whether the alteration is associated with transfusions in these patients. We studied the expression of this antigen on peripheral blood leucocytes in two groups of patients with refractory anaemia, 22 transfused and 20 non-transfused. We found decreased expression of CD43 on the monocytes and neutrophils of patients receiving transfusions. Other activation molecules were studied (CD11b, CD18) and were found up-regulated suggesting the existence of activated leucocytes in these patients. The increased levels of soluble vascular cellular endothelial molecule after transfusions in these patients suggested vascular endothelial activation in the absence of infection. Given together, these results show that decreased CD43 in the transfused group of MDS patients is associated with an activated endothelial phenotype.     

Characterizing CD43 expression in haematogones using multicolor flow cytometric analysis

Haematogones are precursor B cells commonly detected in small numbers in the bone marrow. Morphologically, haematogones can mimic lymphoblasts and are best distinguished using multicolour flow cytometry with antibody combinations. Haematogones show characteristic and reproducible patterns of antigen expression representing the B-cell maturation sequence. CD43 expression, widely seen in haematopoietic elements, has not been well characterized in haematogones. We demonstrate that CD43 is consistently expressed in haematogones in a reproducible pattern similar to that of CD10 when combined with CD20. We propose that in combination with other markers, CD43 can be useful in the identification of haematogones.     

Molecular and flow cytometric characterization of the CD4 and CD8 T-cell repertoire in patients with myelodysplastic syndrome

We studied 18 patients with myelodysplastic syndrome (MDS), measuring clonality and T-cell receptor Vbeta (TCRBV) expression of CD4 and CD8 T cells by polymerase chain reaction and by flow cytometric analysis of TCRBV families. The CD4 and CD8 T-cell repertoire in most MDS patients is characterized by an abnormal TCRBV-restricted expansion of T cells in CD4 and CD8 cells, and increased expression of the CD8 effector marker CD57 of multiple TCRBV in CD8 cells. Clonality analysis of CD4 and CD8 cells showed that seven of 10 patients analysed had a major clone in the CD8 cells but not in CD4 cells. Furthermore, in one patient we found that both the CD57- and CD57+ fraction contained the clone (which was absent from the TCRBV-negative fraction). These data suggest that, in MDS, multiple T-cell expansions can be found in both helper and cytotoxic T cells, and that, in the CD8 cells, T cells functionally differentiate in vivo from memory to effector T cells. Together, these data support the hypothesis of the involvement of T cells in the pathogenesis of MDS.     

阻塞性睡眠呼吸暂停低通气综合征患者CD4+及CD8+细胞的活化

目的探讨CD4 及CD8 细胞在阻塞性睡眠呼吸暂停低通气综合征(OSAHS)发病中的作用。方法研究对象均进行多导睡眠监测(PSG),随机抽取研究对象,分为正常对照组、轻度OSAHS组、中度OSAHS组和重度OSAHS组各29例,16例重度OSAHS患者同时进行nCPAP治疗1月。流式细胞仪测定CD4 和CD8 细胞分别占总T细胞的百分比,活化的CD4 及CD8 细胞分别占全部CD4 和CD8 细胞的百分比。结果①正常对照组、轻度、中度及重度OSAHS患者,CD4 占总T细胞的百分比分别为71.0%±8.0%、65.0%±4.5%、54.2%±6.8%及43.0%±4.7%;CD8 占总T细胞的百分比分别为24.4%±8.7%、30.3%±5.0%、40.4%±7.0%和49.4%±6.7%。CD4 细胞的活化率分别为4.4%±0.5%、5.0%±0.6%、8.1%±0.5%和9.7%±0.7%;CD8 细胞的活化率分别为7.5%±0.7%、8.2%±0.5%、12.0%±1.1%和13.3%±1.1%。两两对比差异有显著性,P均<0.001。重度OHAHS患者nCPAP治疗后,CD4 细胞占总T细胞的比例明显上升;而CD8 细胞占总T细胞的比例则明显下降。CD4 及CD8 细胞的活化率均明显下降。两两对比差异有显著性,P均<0.05。②Spearman等级相关分析表明,OSAHS的严重程度与CD4 细胞百分比呈负相关,与CD8 细胞、活化的CD4 及CD8 细胞百分比呈正相关(rs分别为-0.5432、0.5166、0.4315、0.4761)。结论OSAHS患者可能存在细胞免疫功能的下降,T细胞包括CD4 细胞及CD8 细胞有异常活化,且病情加重以上变化更明显,nCPAP可逆转这种改变。     

Simultaneous quantitative analysis of the expression of CD64 and CD35 on neutrophils as markers to differentiate between bacterial and viral infections in patients with rheumatoid arthritis

Abstract

Objectives The expression level of CD64 on neutrophils can be used to differentiate between an infection and a disease flare in rheumatoid arthritis (RA) patients. However, the CD64 expression is elevated by both bacteria and viruses, so it cannot be used to distinguish the type of infection. We herein investigated the results of a simultaneous quantitative analysis of the expression of CD64 and CD35 on neutrophils to determine whether these molecules can be used to distinguish between bacterial and viral infections in RA patients.

Methods We collected blood from 22 RA patients with pathogen-proven infections (15 bacterial and 7 viral infections). Blood samples were stained with QuantiBRITE CD64PE/CD45PerCP and CD35PE, and the mean fluorescence intensities were assessed by a flow cytometer. The mean numbers of molecules were calculated using QuantiBrite PE beads.

Results We calculated the ratio of CD64 to the CD35 level (CD35/CD64), and used a cut-off value of 2.8 for the CD35/CD64 ratio. At this value, the sensitivity for diagnosing a bacterial infection was 87%, and the specificity was 86%.

Conclusions Simultaneous quantitative analysis of CD64 and CD35 expression on neutrophils might be useful to distinguish between bacterial and viral infections in RA patients.     

卡维地洛对缺氧、再供氧心肌细胞缝隙连接通道蛋白43表达的影响

目的:检测卡维地洛(Cavedilol,CVD)对缺氧再供氧时心肌细胞缝隙连接通道蛋白43(Conexin43,CX43)的基因表达和CX43通道蛋白变化的影响。方法:原代培养心肌细胞,随机分为2组:未用药组,CVD组。建立缺氧、再供氧模型,分别于正常、缺氧30min、再供氧1h、2h、3h、6h搜集细胞。逆转录聚合酶链式反应(RT-PCR)检测CX43 mRNA表达、蛋白免役印迹法(Western blot)检测CX43蛋白的含量。结果:未用药组的心肌细胞缺氧30min时CX43 mRNA表达与蛋白含量和正常相比无显著差异(P>0.05)。再供氧1h、2h、3h、6h则分别减少了39.16%、45.00%、46.67%、51.67%,和正常时相比差异显著(P<0.01)。其中再供氧1h下降幅度最大。用CVD干预后再供氧1h、2h、3h、6h则分别减少了22.95%、27.87%、30.33%、35.25%(P<0.01)。再供氧1h、6h的下降幅较未用药组分别减少了41.39%、31.78%,差异显著(P<0.01)。结论:心肌细胞缺氧再供氧时,其CX43基因表达和蛋白含量明显减少,卡维地洛可抑制CX43降解。     

2例骨髓巨核细胞胞浆表达CD34的病例临床特点分析

目的：分析巨核细胞胞浆表达CD34抗原的病例的临床特点以及早期诊断思考。方法：回顾性分析1例MDS-SLD患者和1例MDS/MPN分型中的CMML-1患者的临床特点、骨髓涂片、骨髓活检免疫组化染色、骨髓小巨核酶标(CD41a)染色、骨髓细胞遗传学及分子生物学的结果。结果：MDS-SLD患者骨髓细胞学增生减低,各系细胞未见明显发育异常,骨髓小巨核酶标(CD41a)染色可见小单圆核和淋巴样巨核细胞,骨髓活检增生极度活跃伴巨核细胞显著增生、发育异常并且部分表达CD34,基因检测可见MDS相关基因突变;CMML-1患者骨髓原始细胞增多并伴有粒系、红系发育异常,流式细胞学示粒系发育模式异常,细胞遗传学可见5q-、7q-、+8的复杂核型,骨髓活检示巨核细胞显著增生未见发育异常但仍部分表达CD34。结论：CD34表达于巨核细胞胞浆,是种少见的巨核细胞发育异常的表现形式,结合骨髓细胞学,流式细胞学,染色体核型及分子生物学综合判断,对诊断MDS有辅助价值。     

晚期扩张型心肌病患者心肌Cx43蛋白表达的研究

目的:探讨晚期扩张型心肌病(DCM)患者心肌连接蛋白43(Cx43)表达变化及其意义。方法:运用免疫组化和图像分析技术,对5例晚期DCM患者和4例因其他心脏疾病(A对照组)行心脏移植手术切除的心脏及4例机械性损伤死者(B对照组)的左心室心肌Cx43蛋白表达进行定位和定量研究。结果:DCM患者心肌Cx43蛋白表达较清晰,主要位于心肌闰盘处,呈条状、斑点或颗粒状散在分布,有的散在分布于心肌细胞侧边;A对照组表达清楚,位于心肌闰盘处,主要呈条状,少数呈斑点状散在分布,而心肌侧边分布很少;B对照组阳性着色较淡,在闰盘处呈条状分布,少有斑点状散在分布,心肌侧边几无表达。定量检测和统计分析发现,DCM组心肌Cx43蛋白表达的量低于A对照组但高于B对照组。心肌Cx43蛋白表达的平均光密度,DCM组与A对照组、B对照组相比,A对照组与B对照组相比,差异均有统计学意义(P<0.01);心肌Cx43蛋白表达的S值,DCM组、A对照组、B对照组间比较,差异均无统计学意义(P>0.05)。结论:晚期DCM患者心肌Cx43蛋白表达的数量和分布均发生改变,这种变化很可能是导致DCM患者发生心律失常和心功能衰竭的病理基础。     

CD48在类风湿关节炎患者外周血CD8+T细胞上的表达及意义

目的探讨类风湿关节炎（RA）患者CD8^＋T细胞上CIM8的表达及意义。方法选择30例RA患者（RA组）和30名健康人（对照组），采用流式细胞仪测定两组外周血CD8^＋T细胞表面上CD48的平均荧光强度，分析RA患者CD48在CD8^＋T细胞上表达的临床意义。结果RA组CD48^＋CD8^＋T细胞表面平均荧光强度明显低于正常对照组，差异有统计学意义（P〈0．01）。而两组CD48^＋CD4^＋T细胞的表面平均荧光强度差异无统计学意义。结论RA患者CD8^＋T细胞上CD48的表达低于对照组，CD48的表达减低使抑制性T细胞减少可能在RA的发病过程中起作用。     

Roles of Virion-Incorporated CD162 (PSGL-1), CD43, and CD44 in HIV-1 Infection of T Cells

Nascent HIV-1 particles incorporate the viral envelope glycoprotein and multiple host transmembrane proteins during assembly at the plasma membrane. At least some of these host transmembrane proteins on the surface of virions are reported as pro-viral factors that enhance virus attachment to target cells or facilitate trans-infection of CD4⁺ T cells via interactions with non-T cells. In addition to the pro-viral factors, anti-viral transmembrane proteins are incorporated into progeny virions. These virion-incorporated transmembrane proteins inhibit HIV-1 entry at the point of attachment and fusion. In infected polarized CD4⁺ T cells, HIV-1 Gag localizes to a rear-end protrusion known as the uropod. Regardless of cell polarization, Gag colocalizes with and promotes the virion incorporation of a subset of uropod-directed host transmembrane proteins, including CD162, CD43, and CD44. Until recently, the functions of these virion-incorporated proteins had not been clear. Here, we review the recent findings about the roles played by virion-incorporated CD162, CD43, and CD44 in HIV-1 spread to CD4⁺ T cells.     

CD69 expression on neutrophils from patients with rheumatoid arthritis

OBJECTIVE: Since the early activation antigen CD69 has been implicated in the pathogenesis of some inflammatory diseases, we evaluated the expression of the molecule on peripheral blood (PB) and synovial fluid (SF) neutrophils obtained from RA patients and its possible correlation with PB and SF cytokine concentration. METHODS: CD69 membrane expression (and CD11b as control marker) was assessed by indirect immunofluorescence and flow cytometry analysis on purified PB and SF neutrophils. Cytokine levels (GM-CSF, IFN-gamma, TNF-alpha) in plasma and SF supernatants were measured by ELISA. RESULTS: CD69 was absent on control neutrophils, while it was expressed on PB neutrophils from RA patients although no detectable GM-CSF, IFN-gamma or TNF-alpha was observed in their plasma. CD69 expression was still more evident on SF neutrophils from RA patients; 59% had detectable levels of INF-gamma in their SF while GM-CSF and TNF-alpha were detectable in SF from 95% and 33% of RA patients, respectively. However, no correlation was observed between cytokine concentrations and CD69 expression on SF neutrophils. SF but not PB neutrophils from RA patients expressed increased amounts of CD11b when compared to control PB neutrophils without any correlation with CD69 membrane expression. CONCLUSION: The activation antigen CD69 is significantly expressed on PB and SF neutrophils from RA patients. However, the mechanism(s) of induction and its possible role in the pathogenesis of RA remain to be defined.     

共刺激分子CD28 CD152在类风湿关节炎患者T细胞亚群上表达异常的研究

目的观察共刺激分子CD28,CD152在类风湿关节炎(RA)患者的T细胞亚群上的表达异常情况,探讨RA的发病机制及治疗手段.方法用流式细胞仪采用直接免疫荧光法测定39例RA患者和20名健康对照人外周血T细胞表面标志CD3,CD4,CD8的表达情况及CD28,CD152在CD4+T和CD8+T细胞上的表达.结果 RA患者CD3+CD4+细胞较正常对照组显著增高(P＜0.01),CD3+CD8+细胞较正常对照组显著降低(P＜0.05),CD4+T细胞上CD28的表达较对照组显著降低(P＜0.05),而CD8+T细胞上CD28的表达与对照组差异无显著性(P＞0.05);CD4+T和CD8+T细胞上CD152的表达都较对照组显著增高(P＜0.01).结论在RA患者的细胞免疫活化过程中首先表现为B7/CD28信号途径占优势,T细胞被激活,激活的T细胞大量分泌CD152,它与CD28竞争结合B7分子,CD152/B7途径转而占优势,下调或终止T细胞反应.同时CD28+细胞数目的减少或功能缺陷造成RA患者外周血单个核细胞凋亡加速,是诱发RA患者的局部病理损害的原因.阻断CD152和B7的相互作用可增强特异性T细胞应答,为RA的免疫学治疗提供理论依据.     

地西他滨对白血病细胞系中连接蛋白43的作用和机制

目的:探讨地西他滨对白血病细胞中连接蛋白43(Cx43)的作用和机制。方法 :蛋白印迹法(Westernblot)检测去甲基化药物地西他滨对NB4-MR2、U937细胞中Cx43水平表达的影响以及加入蛋白酶体抑制剂MG132对Cx43表达的影响。实时定量PCR检测地西他滨对NB4-MR2、U937细胞中Cx43 RNA水平的影响。结果:地西他滨明显下调MR2细胞中Cx43表达,对其RNA水平没有明显影响;地西他滨明显缩短Cx43蛋白的半衰期。加入蛋白酶体抑制剂MG132可明显抑制地西他滨引起的Cx43蛋白的减少。结论:地西他滨通过蛋白酶体途径减少Cx43的水平,可能会影响其治疗效果。     

慢性肾炎患者外周血共刺激分子CD28和CD137水平变化研究

目的　研究慢性肾炎患者外周血共刺激分子CD2 8和CD1 37的表达特点及其在慢性肾炎免疫病理机制中的作用。方法　采用免疫荧光标记和流式细胞仪分析 ,对 5 2例慢性肾炎患者外周血共刺激分子CD2 8、CD1 37和T淋巴细胞亚群的表达进行检测。结果　慢性肾炎患者T细胞亚群明显失衡 ,表现为CD4减少 ,CD8增加 ,CD4 CD8比值显著降低。共刺激分子CD2 8表达显著低于正常对照组 (P <0 0 1) ,且CD+4 CD+2 8T细胞和CD+8CD+2 8T细胞均显著减少 (P <0 0 1)。共刺激分子CD1 37表达显著高于正常对照组 (P <0 0 1)。结论　慢性肾炎患者外周血T细胞亚群失衡和T细胞活化所必需的共刺激分子CD2 8、CD1 37异常表达 ,可能在慢性肾炎发生和病变进展中起着重要作用