系统性红斑狼疮患者外周血CD4^＋CD25^＋highCD127lowTreg和CD4^＋CD25^＋Treg水平测定及分析

目的观察系统性红斑狼疮（SLE）患者外周血CD4^＋CD25highCD127low调节性T细胞（Treg）和CD4^＋CD2^＋5Treg水平变化。方法用流式细胞术检测15例活动期SLE患者（SLE组）及20例健康查体者（对照组）外周血淋巴细胞亚群及CD4^＋CD25highCD127lowTreg、CD4^＋CD2^＋5Treg水平。结果 SLE组外周血中T细胞、B细胞及NK细胞比例与对照组比较无显著差异;SLE组外周血CD4^＋CD25highCD127lowTreg和CD4^＋CD2^＋5Treg水平均显著高于对照组（P〈0.05）。结论活动期SLE患者外周血中CD 4^＋CD25 highCD127 lowTreg和CD 4^＋CD 2^＋5 Treg水平显著升高;此是否与应用免疫抑制剂致患者发生自身免疫逃逸有关尚待进一步探讨。     

诱导缓解治疗对系统性红斑狼疮患者外周血CD4^＋CD25^＋T细胞表达的影响

目的探讨CD4^＋CD25^＋调节性T细胞在系统性红斑狼疮（SLE）患者诱导缓解治疗前后外周血的表达及其临床意义。方法入选28例SLE患者和15例正常对照者（对照组）。用流式细胞仪检测SLE患者和对照组的外周血CD4^＋CD25^＋T细胞阳性率。结果SLE患者在诱导缓解治疗前后CD4^＋CD25^＋调节性T细胞比率均低于对照组（P〈0．05）;诱导缓解治疗后患者外周血CD4^＋CD25^＋调节性T细胞比率较治疗前回升,两者间比较无统计学意义（P〉0．05）;SLE合并肾损害者CD4^＋CD25^＋T细胞比率显著低于未合并肾损害者（P〈0．05）。结论SLE患者外周血CD4^＋CD25^＋调节性T细胞数量显著低于正常人,合并肾损害者更明显,且CD4^＋CD25^＋T细胞比率和狼疮活动性指数之间存在相关性。诱导缓解治疗上调了患者外周血CD4^＋CD25^＋T细胞的数量。     

系统性红斑狼疮患者外周血调节性T细胞与TGF-β水平变化及其意义

目的 探讨调节性T细胞及TGF-β在系统性红斑狼疮（SLE）发病中的作用机制。方法 采用流式细胞仪检测54例SLE患者（SLE组）及20例健康人（对照组）外周血CD4^＋CD25^＋T细胞和CD＋CD25highT细胞比率．ELISA法定量检测血清TGF-β表达水平。结果 ①SLE组初发SLE者CD＋CD＋T细胞和CD4^＋CD25^＋T细胞比率照著低于对照组，抗ds—DNA（＋）者CD4＋CD25highT细胞比率低于对照组，抗ds—DNA（-）者CD4＋CD25＋T细胞和CD4＋CD25highT细胞比率与对照组比较无明显差异；②SLE组TGF—β水平较对照组显著降低。其中抗ds—DNA（＋）者较抗ds—DNA（-）者降低；③CD4＋CD25＋T细胞与抗C1q抗体呈负相关，与TGF—β无明显相关性。TGF—β的表达量与血红蛋白量、血小板量和红细胞量呈正相关。结论 调节性T细胞明显降低可能参与了SLE的发病。其免疫抑制功能的发挥可能有赖于TGF—β。     

系统性红斑狼疮患者骨髓间质干细胞对B淋巴细胞免疫抑制作用的初步研究

目的：探讨系统性红斑狼疮（SLE）患者骨髓间质干细胞（MSCs）体外对B淋巴细胞的免疫调节作用是否存在异常。方法：采用直接贴壁法分离培养正常人及SLE患者MSCs。免疫磁珠法分选正常人外周血B淋巴细胞,与MSCs共培养,流式细胞术检测B细胞凋亡及表面标志表达,3H掺入法检测B细胞增殖,酶联免疫吸附法（ELISA）检测培养上清中免疫球蛋白IgG、IgM和IgA水平。结果：①B细胞＋正常MSCs共培养组B细胞增殖（4307±308）cpm较单纯B细胞培养组（7059±346）cpm降低（P〈0.05）;②B细胞＋正常MSCs共培养组B细胞凋亡率（14±7）%低于单纯B细胞培养组（25±8）%（P〈0.05）;③B细胞＋正常MSCs共培养组B细胞表面CD86表达率（53±5）%较单纯B细胞培养组（66±10）%低（P〈0.05）;④与MSCs共培养后,B细胞分泌免疫球蛋白IgG、IgM和IgA较单纯B细胞培养显著减少（P〈0.05）;⑤B细胞＋狼疮MSCs共培养组与B细胞＋正常MSCs共培养组比较,B细胞增殖、凋亡、CD86表达和Ig分泌两组间差异无统计学意义。结论：MSCs在体外对B细胞有抑制作用,SLE患者骨髓MSCs与正常MSCs相比,对B细胞的表面刺激分子表达、增殖、Ig分泌有相似的抑制作用。     

CD4+CD25+调节性T细胞与克罗恩病发病关系

目的研究克罗恩病（CD）患者外周血白细胞介素（IL）-6水平与外周CD4＋CD25^＋调节性T细胞（Treg细胞）频率及体外抑制功能的变化在CD发病中的作用。方法应用流式细胞术检测CD患者与正常对照者外周CD4^＋CD25^＋Treg细胞的频率及表型以及特征性标志叉状头／翅膀状螺旋转录因子（Foxp3）的表达，同时通过MACS缓冲液分选出外周血CD4^＋CD25^＋T细胞和CD4＋CD25^-T细胞，应用[^3H]-胸腺嘧啶渗入法研究CD4^＋CD25^＋T细胞对自体CD4^＋CD25^-效应T细胞增殖的抑制能力。酶联免疫吸附法（ELISA）检测外周血IL-6水平。结果活动性CD患者外周血IL-6水平显著高于非活动性患者及正常对照者。活动性CD患者外周CD4^＋T细胞中CD4^＋CD25^＋Foxp3^＋T细胞的频率显著低于非活动性CD患者，差异有统计学意义。体外抑制功能试验同样提示活动性CD患者的CD4^＋CD25^＋Treg细胞抑制功能减弱。结论CD4^＋CD25^＋Treg细胞抑制功能减弱与CD发病可能有关，可初步解释CD患者出现的免疫耐受缺失现象。     

抗CD137单克隆抗体对哮喘患者外周血CD4^＋CD25^＋T淋巴细胞死亡方式的影响

目的探讨抗CD啪单克隆抗体对哮喘患者外周血CD4^＋CD25^＋T淋巴细胞的影响。方法采用密度梯度离心法及尼龙棉柱法分离16例健康志愿者（对照组）及12例哮喘患者（哮喘组）外周血T淋巴细胞,磁性细胞分离器（MACS）分离得到CD4^＋CD25^＋T淋巴细胞,分别利用电镜及流式细胞仪观察、检测抗CD137单克隆抗体干预72h的细胞自噬率、凋亡率、胀亡率及FOXp3的表达。结果抗CD137单克隆抗体干预后两组外周血CD4^＋CD25^＋T淋巴细胞自噬率及凋亡率均增加,但哮喘组均低于对照组。结论抗CD137单克隆抗体可促进CD4^＋CD25^＋T淋巴细胞凋亡和自噬。     

系统性红斑狼疮骨髓T细胞活化及其与病情活动的相关性分析

目的 探讨系统性红斑狼疮（SLE）患者骨髓T淋巴细胞的活化状态及多种活化的T细胞亚群与疾病活动指标之间的相关性。方法 SLE患者11例（其中活动期6例，非活动期5例）和健康对照8名。应用流式细胞术比较活动期和非活动期SLE患者骨髓T细胞CD25、人类白细胞抗原（HLA）-DR的表达。用直线相关分析活化T细胞亚群与SLE疾病活动性评分（SLEDAI）、尿蛋白定量（24h）、血清补体C3、C4的相关性。结果 活动期SLE、非活动期SLE与正常对照相比骨髓T细胞CD25、HLA—DR的表达，差异均无统计学意义（P〉0．05）。活动期SLE骨髓T细胞HIJA—DR^＋、CD4^＋HLA—DR^＋、CD8^＋HLA—DR^＋的表达均明显高于正常对照外周血（P〈0．05）。11例SLE患者骨髓CD3^＋HLA—DR^＋、CD4^＋HLA—DR^＋细胞与C3之间均呈显著负相关（r=-0．682，r=-0．675，P均〈0．05）；CD3^＋HLA—DR^＋、CD8^＋-HLA—DR^＋细胞与尿蛋白定量（24h）之间均呈显著正相关（r=-0．712，r=-0．688，P均〈0．05）。活动期SLE骨髓CD3^＋HLA—DR^＋、CD8^＋HLA—DR^＋细胞与C3之间均呈显著负相关（r=-0．943，r=-0．829，P均〈0．05）。结论 活动期SLE患者骨髓T细胞活化明显高于正常对照外周血，且骨髓中活化的T细胞与疾病活动指标相关。     

系统性红斑狼疮患者T细胞活化及其对CD34+细胞的免疫调节

系统性红斑狼疮（SLE）T、B细胞的异常活化以及炎症因子异常导致了SLE患者的多系统损害。造血系统是SLE患者受累的器官之一，导致外周血细胞减少。免疫紊乱可影响骨髓造血和造血微环境。CD34^＋细胞是非均质性细胞群，其中含有造血干细胞和不同分化阶段的各系造血祖细胞，具有自我更新、多向分化的特性和重建造血和免疫系统的功能。骨髓中CD34^＋细胞的增殖、分化、凋亡的调节主要依赖免疫系统，用CD34^＋细胞移植治疗难治性SLE有一定的疗效。去除T细胞对移植后狼疮的复发有预防作用。提示T细胞活化在SLE发病中有重要作用。本文就活性T细胞对CD34^＋细胞的免疫调节进行综述。     

SLE患者外周血CD4+ CD25+调节性T细胞及相关基因Foxp3的变化

目的研究系统性红斑狼疮（SLE）合并狼疮性肾炎患者经肾上腺糖皮质激素（简称激素）冲击治疗后，外周血CD4^＋CD25^＋调节性T细胞（regulatoryTcell，Treg）及相关基因Foxp3表达的变化，从而探讨CD4^＋CD25^＋Treg和Foxp3与SLE发病的相关性。方法采用流式细胞术检测SLE患者外周血单个核细胞（PBMC）中CD4^＋CD25^＋T、CD4^＋CD25highT细胞数量的变化，RTPCR检测PBMC中CD4^＋CD25^＋Treg功能相关基因Foxp3mRNA的表达。结果激素冲击治疗后的SLE患者CD4^＋CD25^＋T／CD4^＋T及CD4^＋CD25highT／CD4^＋T比值高于正常对照组；Foxp3mRNA水平表达与对照组差异不显著。结论CD4^＋CD25^＋Treg数量和功能的变化可能参与SLE的发病，激素可能通过提升CD4^＋CD25^＋Treg治疗SLE。     

rhG-CSF未经动员与动员后供者外周血淋巴细胞与干细胞采集物的细胞构成及功能比较

目的比较重组人粒细胞集落刺激因子（rhG-CSF）动员后供者外周血干细胞（PBSC）采集物与未经动员供者外周血淋巴细胞采集物的细胞构成及功能。方法取异基因造血干细胞移植供者的rhG-CSF动员后PBSC采集物（A组）和未经动员的淋巴细胞采集物（B组）,以流式细胞术测定采集物组分、T细胞亚群、树突细胞（DC）及其亚群、CD14^＋细胞和CD19^＋细胞B7分子的表达、CD4^＋T细胞IL-4和IFNγ等细胞因子的分泌情况,四甲基偶氮唑盐法测定T淋巴细胞增殖能力。结果两组采集物的CD3^＋、CD4^＋、CD34^＋、CD14^＋细胞比例有明显差异,A组DC细胞及其亚群的比例明显高于B组,尤以DC2升高为著（P=0．000）,CD14^＋细胞上B7分子的表达A组明显低于B组,CD19^＋细胞上B7分子的表达无明显差异,分析两组CD4细胞内因子的分泌情况,A组的Ⅱ类细胞因子IL-4及IL-4／IFNγ均明显高于B组（P值分别为0．044,0．012）,经rhG—CSF动员后采集物的T淋巴细胞增殖能力明显下降。结论动员后的PBSC采集物较未经动员的淋巴细胞采集物富集了更多的CD34^＋、CD14^＋细胞,同时rhG—CSF动员后DC2比例的明显升高使得CD4细胞向Th2分化,PBSC含有更多的Ⅱ类细胞因子和其T细胞增殖能力的下降、共刺激分子的下调均提示PBSC较供者淋巴细胞输注更少地引起急性移植物抗宿主病的发生。     

Human mesenchymal stem cells require monocyte-mediated activation to suppress alloreactive T cells

Human bone marrow-derived mesenchymal cells (MSCs) are precursors of nonhematopoietic mesenchymal cells of the bone marrow microenvironment. MSCs were shown to inhibit alloreactive T lymphocytes, but the mechanism and mediators of this effect are not fully understood. Here we describe a novel interaction between blood monocytes and bone marrow-derived, culture-expanded MSCs, which results in inhibition of T-lymphocyte activation. We found that CD14+ monocytes from blood activate MSCs to secrete inhibitory molecules that lead to inhibition of alloreactive T cells. This cellular communication is not contact-dependent, but rather is mediated by soluble factors that include interleukin (IL)-1beta. MSC-mediated inhibition of alloreactive T lymphocytes is associated with downregulation of activation markers CD25, CD38, and CD69 detected both in CD4+ and CD8+ T lymphocytes. The cytokines secreted by MSCs that mediate T-cell inhibition include transforming growth factor-beta1, but not IL-10. The interaction between blood monocytes and the MSCs represents a unique immune regulatory paradigm that can potentially be exploited in clinic.     

Telomerase activity in B and T lymphocytes of patients with systemic lupus erythematosus

OBJECTIVE: To evaluate telomerase activity as a marker of lymphocyte proliferation in systemic lupus erythematosus (SLE). METHODS: CD19+, CD4+, and CD8+ lymphocytes were isolated from the peripheral blood of nine patients with SLE and nine healthy controls by means of magnetic bead-coupled antibodies and tested for telomerase activity with the TRAP assay. RESULTS: Telomerase activity was significantly increased in CD19+ B cells from patients with SLE. CD4+ and CD8+ T cells from lupus patients displayed increased mean telomerase activity, although the difference from normal controls did not reach statistical significance. CONCLUSIONS: Increased telomerase activity in the B and the T cell lineage might indicate activation and proliferation of these lymphocytes.     

Alterations of dendritic cells in systemic lupus erythematosus: phenotypic and functional deficiencies

OBJECTIVE: Systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by B cell hyperactivity and defective T cell functions, including interleukin-2 production and proliferation. The defects in T cell function may result from underlying defects in antigen-presenting cell (APC) function. The present study was undertaken to investigate phenotypic and functional characteristics of peripheral blood dendritic cells (DC), as the most potent APC, in SLE patients in comparison with healthy controls. METHODS: Samples from 25 SLE patients and 15 healthy controls were studied. To identify DC, peripheral blood mononuclear cells were double stained with monoclonal antibodies against lineage marker (lin)-specific molecules CD3, CD19, CD14, and CD16, versus CD4. DC were characterized phenotypically by flow cytometry. The stimulatory capacity of DC was determined by proliferation of T cells in the mixed lymphocyte reaction (MLR), which was assessed by measurement of tritiated thymidine incorporation in studies using granulocyte-macrophage colony-stimulating factor-activated, DC-enriched APC. Correlations between DC counts and phenotype and clinical parameters in SLE patients were determined. RESULTS: Lin-, HLA-DR+, CD4+ DC were, on average, 50% less frequent in SLE patients than in controls. Moreover, among DC, the proportions of B7+ and CD40+ cells were reduced and, in particular, the CD11c+ subset was reduced by an average of 80% in SLE patients. Functional analysis of DC-enriched APC from SLE patients revealed a diminished T cell-stimulatory capacity in both the allogeneic and the antigen-specific MLR, as compared with healthy individuals. Although the frequencies of DC were weakly inversely correlated with disease activity and/or current treatment protocols, our data suggest a disease-intrinsic defect. CONCLUSION: The considerable alterations of DC and DC subsets in SLE patients may contribute to the pathogenic mechanisms involved in the disease.     

间充质干细胞对系统性红斑狼疮CD4+Foxp3+T淋巴细胞的调节

目的 探讨同种异体骨髓间充质干细胞(MSC)体内外对系统性红斑狼疮(SLE)患者外周血CD4+Foxp3+T淋巴细胞及人脐带MSC移植对MRL/lpr鼠脾脏和淋巴结CD4+Foxp3+T淋巴细胞水平的影响.方法 血缘相关供者骨髓中分离培养MSC移植治疗5例SLE患者,采用流式细胞术检测移植前后外周血CD4+Foxp3+T淋巴细胞百分率.7例SLE患者外周血单个核细胞(PBMC)分别与SLE患者和正常人骨髓MSC按不同比例体外共培养72 h,检测共培养后PBMC中CD4+Foxp3+T淋巴细胞百分率.MRL/Ipr鼠输注脐带MSC后检测脾脏和淋巴结CD4+Foxp3+T淋巴细胞百分率.结果 SLE患者异基因骨髓MSC移植后1周外周血CD4+Foxp3+T淋巴细胞百分率(4.8±1.6)%和移植后3个月(6.0±2.6)%均较移植前(2.1±1.2)%明显升高(5例,P<0.05).正常骨髓MSC与SLE患者PBMC共培养后CD4+Foxp3+T淋巴细胞百分率明显升高(P<0.05).且存在剂量依赖性,狼疮MSC也可上调SLE患者CD4+Foxp3+T淋巴细胞水平,但作用较正常MSC弱(P<0.05);正常MSC培养上清也可上调SLE患者PBMC中CD4+Foxp3+T淋巴细胞水平,但作用弱于MSC:PBMC=1:1组(P<0.05).MRL/Ipr鼠经1次或3次脐带MSC移植后脾脏CD4+Foxp3+T淋巴细胞百分率均较对照组高(P<0.05),但淋巴结CD+Foxp3+T淋巴细胞百分率均较对照组低(p<0.01),1次和3次移植组间差异无统计学意义.结论 异基因甚至异种MSC移植可上调SLE患者或MRL/Ipr鼠CD4+Foxp3+T淋巴细胞水平,同时体外试验也得出相同结论,且体外上调作用呈一定剂量依赖性,CD4+Foxp3+T淋巴细胞水平上调可能是MSC移植治疗SLE有效的机制之一.     

Quantitative and qualitative normal regulatory T cells are not capable of inducing suppression in SLE patients due to T-cell resistance

Previous reports have suggested that regulatory T cells (Treg) are abnormal in patients with systemic lupus erythematosus (SLE). In the present work, we quantified CD4+FOXP3+ Treg cells in patients with SLE and found no quantitative alterations. However, we found a clear defect in suppression assays. Surprisingly, SLE-derived Treg cells exhibited a normal phenotype and functional capacity. Conversely, SLE-derived CD4+CD25(-) effector T cells resisted suppression by autologous and allogeneic regulatory cells. Our findings strongly suggest that the defect in T-cell suppression observed in SLE is because of effector cell resistance and not because of an abnormal regulatory function.     

Lymphocyte subset reconstitution following human allogeneic bone marrow transplantation: differences between engrafted patients and graft failure patients.

To define the relationship between hematopoietic reconstitution and lymphocyte subset analysis in human allogeneic bone marrow transplantation (BMT), we compared lymphocyte subset reconstitution during the first 4 weeks after BMT in nine engrafted patients with that in three graft failure patients using flow cytometry. Marked differences were observed between the two groups. In graft failure patients, the percentage of CD3+ lymphocytes had increased 2 weeks after BMT by over 90% (p less than 0.05). The percentage of CD16+ lymphocytes and CD16+ CD57- lymphocytes did not increase (CD16+ at 3 and 4 weeks: p less than 0.05, CD16+ CD57- at 3 weeks; p less than 0.05, at 4 weeks: p less than 0.01), nor did the percentage of CD8+ 11b+ lymphocytes. The percentage of CD8+ 11b- lymphocytes had increased markedly 2 weeks after BMT (at 2 weeks: p less than 0.05, at 3 and 4 weeks: p less than 0.01). Of particular interest is the difference in the percentage of CD3+, CD16+, and CD8+ CD11b- T cells between the two groups. These cells may play a role in allogeneic bone marrow cell engraftment.     

系统性红斑狼疮患者CD4~+CD25~+CD127~(low/-)调节性T细胞中Foxp3的表达及免疫抑制功能研究

目的 研究系统性红斑狼疮(SEE)外周血中调节性T细胞不同标志以及调节性T细胞在SLE发病中的作用;探讨CD127与Foxp3的相关性,明确CD127定义调节性T细胞的特异性;鉴定CD4~+CD25~+CD127~(low/-)T淋巴细胞免疫抑制功能.方法 ①采用四色直接荧光素标记法和多参数流式细胞术检测40例SLE患者(19例初发和21例缓解)及15名健康对照外周血CD4~+CD25~+T淋巴细胞、CD4~+CD25~+CD127~(low-)T淋巴细胞、CD4~+CD25~+Foxp3~+T淋巴细胞、CD4~+CD25~(high)T淋巴细胞、CD4~+CD25~(high)CD127~(low/-)T淋巴细胞、CD4~+CD25~(high)Foxp3~+T淋巴细胞以及CD4~+CD127~(low/-)Foxp3~+T淋巴细胞占CD4~+T淋巴细胞的比率,并且将7种调节性T细胞比率与外周血抗双链DNA(dsDNA)等抗体及SLE疾病活动指数(SLEDA1)评分等进行相关性分析.②以流式细胞分选术结合细胞培养技术,检测和分析3例SLE患者和4名健康人外周血中CD4~+CD25~+CD127~(low/-)调节性T细胞对CD4~+CD25~-效应性T细胞增殖的抑制作用.采用两样本均数的t检验,重复测量的方差分析,Pearson相关与Spearman相关分析进行统计学处理.结果 ①SLE患者组7种调节性T细胞比率分别为(6.1±1.7)%,(3.1±1.3)%,(2.1±1.0)%,(1.6±0.3)%,(0.97±0.28)%,(0.69±0.23)%和(0.71±0.35)%.与健康对照组比较:SLE患者组前6种调节性T细胞比率均低于健康对照组(P<0.05).②SLE患者组:CD4~+CD25~+Foxp3~+、CD4~+CD25~(high)Foxp3~+T淋巴细胞比率与IgA呈正相关;CD4~+CD25~(high)CD127~(low/-)T淋巴细胞比率与抗SSB抗体呈正相关.③SLE患者初发组和缓解组比较:SLE患者初发组7种调节性T细胞中除CD4~+CD127~(low/-)Foxp3~+T淋巴细胞比率外,其余均低于缓解组(P<0.05).④SLE患者初发组治疗前后比较:激素治疗前6种调节性T细胞比率均低于激素治疗后(P<0.05).⑤SLE患者初发组、缓解组和对照组中,CD4~+CD25~+T淋巴细胞及CD4~+CD25~(high)T淋巴细胞中Foxp3的表达与CD127低表达均呈正相关.⑥SLE患者、健康人CD4+CD25-效应性T细胞的体外增殖都可以被自身CD4~+CD25~+CD127~(low/-)调节性T细胞所抑制,但SLE患者的抑制率明显低于健康对照.结论 SLE的免疫异常可能与调节性T细胞的数量和功能缺陷有关;CD127可能代替Foxp3作为调节性T细胞特异性的表面标记物.     

CD8+CD28- regulatory T lymphocytes prevent experimental inflammatory bowel disease in mice

BACKGROUND & AIMS: Immune responses to innocuous intestinal antigens appear tightly controlled by regulatory T lymphocytes. While CD4+ T lymphocytes have recently attracted the most attention, CD8+ regulatory T-cell populations are also believed to play an important role in control of mucosal immunity. However, CD8+ regulatory T-cell function has mainly been studied in vitro and no direct in vivo evidence exists that they can control mucosal immune responses. We investigated the capacity of CD8+CD28- T cells to prevent experimental inflammatory bowel disease (IBD) in mice. METHODS: CD8+CD28- regulatory T cells were isolated from unmanipulated mice and tested for their capacity to inhibit T-cell activation in allogeneic mixed lymphocyte cultures in vitro and to prevent IBD induced by injection of CD4+CD45RB(high) cells into syngeneic immunodeficient RAG-2 mutant mice. RESULTS: CD8+CD28- T lymphocytes inhibited proliferation and interferon gamma production by CD4+ responder T cells in vitro. CD8+CD28- regulatory T cells freshly isolated from spleen or gut efficiently prevented IBD induced by transfer of colitogenic T cells into immunodeficient hosts. Regulatory CD8+CD28- T cells incapable of producing interleukin-10 did not prevent colitis. Moreover, IBD induced with colitogenic T cells incapable of responding to transforming growth factor beta could not be prevented with CD8+CD28- regulatory T cells. CD8+CD28+ T cells did not inhibit in vitro or in vivo immune responses. CONCLUSIONS: Our findings show that naturally occurring CD8+CD28- regulatory T lymphocytes can prevent experimental IBD in mice and suggest that these cells may play an important role in control of mucosal immunity.     

Biologic characteristics of bone marrow-derived mesenchymal stem cells from a patient with thalassemia syndrome

Introduction: Mesenchymal stem cells (MSCs) are capable of self‐renewal and differentiating morphologically and functionally into several mesenchymal tissues. There have been contrasting data on whether MSCs are altered in various hematologic disorders. Methods: We isolated bone marrow (BM)–derived MSCs from a patient with thalassemia syndrome to compare phenotypic and functional characteristics to those from normal healthy donor. Results: No differences were observed between MSCs from thalassemia syndrome (T‐MSCs) and those from normal healthy donor in terms of morphology, phenotype, karyotype, multidifferentiation capacity. In mixed lymphocyte reaction, T‐MSCs strongly inhibited the proliferation of allogeneic T cells in association with reduced proportion of CD3⁺, CD4⁺, and CD8⁺ cells. Furthermore, the fraction of Treg cells was increased under the culture with T‐MSCs, suggesting that T‐MSCs exert normal immunomodulatory function. In addition, T‐MSCs expressed hematopoietic cytokines and supported hematopoiesis, which was comparable to those from normal BM‐derived MSCs. Conclusion: T‐MSCs exhibited normal phenotype, karyotype as well as normal immunomodulatory function, and autologous MSCs from patients with thalassemia syndrome may be an attractive source of stem cell in terms of hematopoietic support as well as immunomodulatory activity.     

MRL/Mp CD4+,CD25- T cells show reduced sensitivity to suppression by CD4+,CD25+ regulatory T cells in vitro: a novel defect of T cell regulation in systemic lupus erythematosus

OBJECTIVE: To investigate the hypothesis that loss of suppression mediated by peripheral CD4+,CD25+ regulatory T cells is a hallmark of systemic lupus erythematosus (SLE). METHODS: Mice of the MRL/Mp strain were studied as a polygenic model of SLE. Following immunomagnetic selection, peripheral lymphoid CD25+ and CD25- CD4+ T cells were cultured independently or together in the presence of anti-CD3/CD28 monoclonal antibody-coated beads. Proliferation was assessed by measuring the incorporation of tritiated thymidine. RESULTS: While MRL/Mp CD4+,CD25+ regulatory T cells showed only subtle abnormalities of regulatory function in vitro, syngeneic CD4+,CD25- T cells showed significantly reduced sensitivity to suppression, as determined by crossover experiments in which MRL/Mp CD4+,CD25- T cells were cultured with H-2-matched CBA/Ca CD4+,CD25+ regulatory T cells in the presence of a polyclonal stimulus. CONCLUSION: Our findings highlight a novel defect of peripheral tolerance in SLE. Identification of this defect could open new opportunities for therapeutic intervention.