首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 0 毫秒
1.
CD4^ CD25^ 调控T细胞是一群表型和功能特异的T细胞亚群,能抑制CD4^ CD25^-和CD8^ T细胞的活化和增殖,以及IL-2和IFN-γ的产生,在移植免疫耐受中发挥着重要的作用,其免疫调控机理仍不明确。CD4^ CD25^ 在体外能有效地被分离、活化和扩增,并能保持其免疫调控能力,其活化后的免疫抑制功能是抗原非特异性的。体外活化和扩增的CD4^ CD25^ 调控T细胞有广阔的应用前景。  相似文献   

2.
本研究探讨致敏小鼠CD4+ CD25+调节性T细胞的分选及体外扩增。流式细胞术检测致敏小鼠及正常小鼠体内CD4+ CD25+ Treg细胞水平,免疫磁珠分选方法从小鼠脾细胞中分选出CD4+T细胞、CD4+ CD25+ Treg细胞和CD4+ CD25-T细胞,负载抗CD3/CD28单克隆抗体MACSiBead联合IL-2共同刺激CD4+ CD25+ Treg细胞进行体外扩增培养,用0.4%台盼蓝染色并计数检测细胞的活性,流式细胞术检测分选后细胞纯度、主要表面标记及Foxp3基因的表达。结果表明:致敏小鼠体内CD4+ CD25+ Treg水平较正常小鼠升高(P<0.05)。分选出CD4+ CD25+ Treg细胞纯度平均达到87%,细胞活性大于97%,高表达Foxp3基因。体外扩增2周后细胞数扩增倍数能够达到42倍,CD4+ CD25+ Treg细胞所占比例为85.32%,Foxp3表达由(76.92±1.72)%稍下降至(75.33±2.11)%(P>0.05)。结论:免疫磁珠分选法能够分选出高纯度的CD4+ CD25+ Treg细胞,该分选方法不影响分选靶细胞的细胞活力;体外成功扩增了CD4+ CD25+ Treg细胞,扩增后的CD4+ CD25+ Treg细胞表面标记及Foxp3基因表达无明显改变。  相似文献   

3.
Peripheral tolerance may be maintained by a population of regulatory/suppressor T cells that prevent the activation of autoreactive T cells recognizing tissue-specific antigens. We have previously shown that CD4+CD25+ T cells represent a unique population of suppressor T cells that can prevent both the initiation of organ-specific autoimmune disease after day 3 thymectomy and the effector function of cloned autoantigen-specific CD4+ T cells. To analyze the mechanism of action of these cells, we established an in vitro model system that mimics the function of these cells in vivo. Purified CD4+CD25+ cells failed to proliferate after stimulation with interleukin (IL)-2 alone or stimulation through the T cell receptor (TCR). When cocultured with CD4+CD25 cells, the CD4+CD25+ cells markedly suppressed proliferation by specifically inhibiting the production of IL-2. The inhibition was not cytokine mediated, was dependent on cell contact between the regulatory cells and the responders, and required activation of the suppressors via the TCR. Inhibition could be overcome by the addition to the cultures of IL-2 or anti-CD28, suggesting that the CD4+CD25+ cells may function by blocking the delivery of a costimulatory signal. Induction of CD25 expression on CD25 T cells in vitro or in vivo did not result in the generation of suppressor activity. Collectively, these data support the concept that the CD4+CD25+ T cells in normal mice may represent a distinct lineage of “professional” suppressor cells.  相似文献   

4.
目的探讨CD4^+CD25^+T细胞在特发性血小板减少性紫癜(ITP)患者发病机制中的作用。方法应用流式细胞术检测ITP患者外周血CD4^+CD25^+T细胞、CD4^+CD25^highT细胞、CD4^+FOXP3^+T细胞、CD4^+CD25^+FOXP3^+T细胞的数量;实时荧光定量PCR检测外周血FOXP3 mRNA的表达水平。将ITP患者和正常人CD4^+CD25^highT细胞与自身CD4^+CD25^-T细胞混合培养,检测CD4^+CD25^high T细胞免疫抑制功能。结果ITP患者外周血中CD4^+CD25^+T细胞约占CD4^+T细胞的(15.64±5.82)%,明显高于正常对照组(9.30±3.95)%(P〈0.01),CD4^+CD25^high T细胞比例为(1.53±0.66)%,与对照组[(1.36±0.55)%]比较差异无统计学意义(P〉0.05);CD4^+FOXP3^+T细胞和CD4^+CD25^+FOXP3^+T细胞分别为(1.82±1.42)%和(1.25±0.94)%,均明显低于对照组[(3.90±1.37)%和(2.65±0.92)%](P值均〈0.01)。ITP患者外周血FOXP3 mRNA表达水平较正常人明显下调(P〈0.01),CD4^+CD25^high T细胞的抑制活性较正常人减弱(P〈0.01)。结论ITP患者中CD4^+CD25^+T细胞FOXP3表达水平降低,抑制活性减弱。  相似文献   

5.
Reactivation of dormant infections causes an immense burden of morbidity and mortality in the world at large. Reactivation can occur as a result of immunosuppression, environmental insult, or aging; however, the cause of reactivation of such infections is often not clear. We have previously shown that persistence of the parasite Leishmania major is controlled by endogenous CD4(+) CD25(+) regulatory T (T reg) cells. In this report, we show that despite efficient parasite clearance at secondary sites of infection, Leishmania superinfection can cause disease reactivation at the primary site. Our results strongly suggest that T reg cells, whose numbers increase in sites of reactivation, are directly responsible for such reactivation. Depletion of CD25(+) cells at the time of secondary challenge prevented disease reactivation at the site of persistent infection while strengthening the expression of immunity at the site of secondary challenge. Finally, transfer of T reg cells purified from infected mice into chronically infected mice was sufficient to trigger disease reactivation and prevent the expression of an effector memory response. Our results demonstrate that after persistence is achieved, an equilibrium between T reg cells and effector lymphocytes, which can be disturbed by superinfection, controls the efficiency of recall immune responses and disease reactivation.  相似文献   

6.
7.
本研究旨在探讨转录因子T-bet、GATA-3和CD4+CD25+调节性T细胞及其转录因子FoxP3在儿童过敏性紫癜(HSP)发病机制中的作用。2009年2月-2010年2月在本院收治的46例急性期HSP患儿(HSP组)及30例健康对照儿童(对照组)纳入研究。采用SYBR GreenⅠ实时荧光定量PCR方法检测外周血单个核细胞T-bet、GATA-3及FoxP3 mRNA的表达。运用流式细胞术检测外周血中T淋巴细胞亚群CD4+CD25+的表达。结果表明,HSP组患儿GATA-3 mRNA相对表达水平(964.30±655.18)显著高于对照组儿童GATA-3 mRNA相对表达水平(78.09±57.20,P<0.01)。HSP组患儿T-bet mRNA(53.98±35.79)、FoxP3 mRNA(32.17±23.04)和CD4+CD25+(5.34±2.51)相对表达水平低于对照组儿童T-bet mRNA(181.56±96.90)、FoxP3 mRNA(147.91±99.15)和CD4+CD25+(7.85±1.97)相对表达水平(P<0.01)。结论:HSP患儿急性期存在Th1特异性转录因子T-betmRNA表达下调,Th2特异性转录因子GATA-3 mRNA表达上调。HSP患儿急性期存在CD4+CD25+调节性T细胞及其特异性转录因子FoxP3 mRNA表达下调,调节性T细胞的减少及由此引发的免疫抑制效应不足可能是HSP急性期免疫失衡的重要原因之一。本研究为从调节性T细胞及其调控的分子机制角度进一步阐明儿童HSP的发病机制提供了实验依据。  相似文献   

8.
CD4(+)CD25(+) regulatory T cells inhibit organ-specific autoimmune diseases induced by CD4(+)CD25(-) T cells and are potent suppressors of T cell activation in vitro. Their mechanism of suppression remains unknown, but most in vitro studies suggest that it is cell contact-dependent and cytokine independent. The role of TGF-beta1 in CD4(+)CD25(+) suppressor function remains unclear. While most studies have failed to reverse suppression with anti-transforming growth factor (TGF)-beta1 in vitro, one recent study has reported that CD4(+)CD25(+) T cells express cell surface TGF-beta1 and that suppression can be completely abrogated by high concentrations of anti-TGF-beta suggesting that cell-associated TGF-beta1 was the primary effector of CD4(+)CD25(+)-mediated suppression. Here, we have reevaluated the role of TGF-beta1 in CD4(+)CD25(+)-mediated suppression. Neutralization of TGF-beta1 with either monoclonal antibody (mAb) or soluble TGF-betaRII-Fc did not reverse in vitro suppression mediated by resting or activated CD4(+)CD25(+) T cells. Responder T cells from Smad3(-/-) or dominant-negative TGF-beta type RII transgenic (DNRIITg) mice, that are both unresponsive to TGF-beta1-induced growth arrest, were as susceptible to CD4(+)CD25(+)-mediated suppression as T cells from wild-type mice. Furthermore, CD4(+)CD25(+) T cells from neonatal TGF-beta1(-/-) mice were as suppressive as CD4(+)CD25(+) from TGF-beta1(+/+) mice. Collectively, these results demonstrate that CD4(+)CD25(+) suppressor function can occur independently of TGF-beta1.  相似文献   

9.
王莲莲  曹霞  魏军 《医学临床研究》2011,28(2):231-232,235
[目的]研究CD4+ CD25+调节性T细胞(CD4+ CD25+Treg细胞)和Foxp3基因表达与子痫前期发病的相关性.[方法]选择住院确诊的妊娠期高血压孕妇12例(A组)、轻度子痫前期(MPE)孕妇14例(B组)、重度子痫前期(SPE)孕妇15例(C组),30例正常妊娠晚期孕妇为对照组(D组),应用流式细胞术检测并比较四组外周血中CD4+ CD25+ Treg和 Foxp3的表达水平.[结果]A组、B组和C组孕妇外周血CD4+ CD25+ Treg 和Foxp3表达水平均显著低于对照组(P〈0.05) C组外周血CD4+ CD25+ Treg和Foxp3表达水平显著低于A组和B组(P〈0.05).[结论]子痫前期患者体内存在CD4+ CD25+ Treg细胞的异常,CD4+ CD25+Treg细胞的数量的减少和Foxp3表达的降低使CD4+ CD25+Treg细胞免疫抑制功能减弱,从而使母胎免疫耐受失衡,导致子痫前期的发生.  相似文献   

10.
CD4 CD25 调节性T细胞是一种除主要表达CD25分子外,还表达CTLA-4和G ITR(糖皮质激素诱导的TNF受体)等的CD4 T细胞亚群,它不但是参与对自身抗原外周耐受的主要T细胞群,而且还作为对外来抗原应答的调节性T细胞,对于维持外周免疫耐受有重要意义[1,2]。已有研究表明,自身免疫病的易  相似文献   

11.
目的探讨CD4+、CD25+调节性T细胞(CD4+、CD25+ Tr)在重型乙型肝炎病人发病机制中的作用。方法采用流式细胞术检测重型乙型肝炎病人及对照组外周血CD4+、CD25+ Tr的水平及应用PCR测定重型乙型肝炎病人及对照组外周血中HBVDNA滴度。结果重型乙型肝炎组外周血CD4+、CD25+ Tr的百分率为(2.63±0.83)%,较慢性乙型肝炎组的(4.15±1.17)%差异有显著性(P〈0.05),较无症状HBV携带者组及健康对照组差异有非常显著性(P均〈0.01);重型乙型肝炎组外周血HBVDNA滴度为1.2×10^4copies/ml,较慢性乙型肝炎组(2.3×10^6copies/ml)和无症状HBV携带者(7.8×105copies/ml)差异有非常显著性(P均〈0.01);不同乙型肝炎病人外周血CD4^+、CD25^+ Tr的百分率与HBVDNA滴度正相关。结论CD4^+、CD25+^ Tr能抑制T细胞对HBV的免疫反应;重型乙型肝炎患者发病与CD4^+、CD25^+ Tr表达过低有关。  相似文献   

12.
目的探讨半乳凝素-10(galectin-10)在CD4 CD25 CD127low/-调节性T细胞(regulatory T cell,Treg)中的表达及其与Foxp3的相关性。方法通过流式细胞术分选健康人外周血和胃癌患者癌旁淋巴结中Treg细胞与CD4 CD25-CD127 T细胞,经微量抽提RNA后,用RT-PCR检测galectin-10和Foxp3的mRNA表达水平。结果galectin-10和Foxp3的mRNA显著表达于Treg细胞,几乎不表达于CD4 CD25-CD127 T细胞。健康人外周血和胃癌患者癌旁淋巴结中的结果一致。结论ga-lectin-10基因高表达于Treg细胞中,可以作为Treg细胞一项新的标志物。  相似文献   

13.
In many cases, induction of CD8(+) CTL responses requires CD4(+) T cell help. Recently, it has been shown that a dominant pathway of CD4(+) help is via antigen-presenting cell (APC) activation through engagement of CD40 by CD40 ligand on CD4(+) T cells. To further study this three cell interaction, we established an in vitro system using dendritic cells (DCs) as APCs and influenza hemagglutinin (HA) class I and II peptide-specific T cell antigen receptor transgenic T cells as cytotoxic T lymphocyte precursors and CD4(+) T helper cells, respectively. We found that CD4(+) T cells can provide potent help for DCs to activate CD8(+) T cells when antigen is provided in the form of either cell lysate, recombinant protein, or synthetic peptides. Surprisingly, this help is completely independent of CD40. Moreover, CD40-independent CD4(+) help can be documented in vivo. Finally, we show that CD40-independent T cell help is delivered through both sensitization of DCs and direct CD4(+)-CD8(+) T cell communication via lymphokines. Therefore, we conclude that CD4(+) help comprises at least three components: CD40-dependent DC sensitization, CD40-independent DC sensitization, and direct lymphokine-dependent CD4(+)-CD8(+) T cell communication.  相似文献   

14.
目的利用不同种类树突状细胞(dendritic cells,DC)体外扩增获得表型和功能稳定的CD4+CD25+Foxp3+调节性T细胞(Treg)。方法免疫磁珠法(MACS)分离Balb/c小鼠CD4+CD25+调节性T细胞,利用与调节性T细胞同基因或异基因成熟DC、未成熟DC和调节性DC刺激其扩增,流式细胞术测定其纯度和表型。以CD4+CD25-T细胞作为反应细胞,验证扩增前后Treg细胞的免疫抑制功能。结果MACS分离的CD4+CD25+调节性T细胞纯度达到(95.38±1.82)%,同基因和异基因DC都能有效刺激Treg细胞体外扩增,其中同基因成熟DC扩增效果最为明显。而且同基因成熟DC扩增后CD4+CD25+调节性T细胞纯度达到(94.16±1.88)%,而且高表达Foxp3分子。当CD4+CD25+调节性T细胞与效应T细胞比例为1∶1时,能够有效的抑制效应T细胞的增殖,而且,同基因成熟DC扩增的CD4+CD25+调节性T细胞的抑制效果比新分离的Treg效果更好。结论同基因成熟DC能够体外扩增表型和功能稳定的Treg细胞。  相似文献   

15.
CD4+CD25+ regulatory T cells contribute to the maintenance of peripheral tolerance by active suppression because their deletion causes spontaneous autoimmune diseases in mice. Human CD4+ regulatory T cells expressing high levels of CD25 are suppressive in vitro and mimic the activity of murine CD4+CD25+ regulatory T cells. Multiple sclerosis (MS) is an inflammatory disease thought to be mediated by T cells recognizing myelin protein peptides. We hypothesized that altered functions of CD4+CD25hi regulatory T cells play a role in the breakdown of immunologic self-tolerance in patients with MS. Here, we report a significant decrease in the effector function of CD4+CD25hi regulatory T cells from peripheral blood of patients with MS as compared with healthy donors. Differences were also apparent in single cell cloning experiments in which the cloning frequency of CD4+CD25hi T cells was significantly reduced in patients as compared with normal controls. These data are the first to demonstrate alterations of CD4+CD25hi regulatory T cell function in patients with MS.  相似文献   

16.
目的:探讨异基因骨髓间充质干细胞(MSCs)移植对小鼠胶原性关节炎 CD4+、CD25+调节性 T 细胞表达的影响。方法选取40只 C57BL/6(H-2b)小鼠,随机分为正常对照组、Ⅱ型胶原性关节炎(CIA)模型组、MSCs 移植治疗组、甲氨蝶呤治疗阳性对照组,每组10只小鼠。除正常对照组外,其余各组弗氏完全佐剂+Ⅱ型胶原诱导小鼠建立 CIA 小鼠模型。分离骨髓单个核细胞后,进行 MSCs 细胞分选及鉴定。美国 BD 公司 FAcscal-iburTM 型流式细胞分析仪对小鼠骨髓 MSCs 进行分选和鉴定。 MSCs 移植采用尾静脉注射,所含细胞数为2×106。移植后第42天全部处死动物观察不同分组小鼠的关节症状及肿胀度,采用流式细胞术检测 CD4+ CD25+浓度,收集数据并做统计分析。结果 MSCs 移植治疗组小鼠关节的肿胀度,与正常对照组比较,差异无统计学意义(P>0.05)。 MSCs 移植组 CD4+ CD25+调节性 T 细胞的表达,与甲氨蝶呤治疗阳性对照组比较,差异有统计学意义(P<0.05);与正常对照组比较,差异无统计学意义(P>0.05)。结论 MSCs 移植治疗小鼠 CIA ,能显著改善关节的肿胀度,并明显上调 CD4+ CD25+表达,故 MSCs 可作为一种新的替代细胞来源用于类风湿性关节炎的移植治疗。  相似文献   

17.
Glutamic acid decarboxylase (GAD)65 is an early and important antigen in both human diabetes mellitus and the nonobese diabetic (NOD) mouse. However, the exact role of GAD65-specific T cells in diabetes pathogenesis is unclear. T cell responses to GAD65 occur early in diabetes pathogenesis, yet only one GAD65-specific T cell clone of many identified can transfer diabetes. We have generated transgenic mice on the NOD background expressing a T cell receptor (TCR)-specific for peptide epitope 286-300 (p286) of GAD65. These mice have GAD65-specific CD4(+) T cells, as shown by staining with an I-A(g7)(p286) tetramer reagent. Lymphocytes from these TCR transgenic mice proliferate and make interferon gamma, interleukin (IL)-2, tumor necrosis factor (TNF)-alpha, and IL-10 when stimulated in vitro with GAD65 peptide 286-300, yet these TCR transgenic animals do not spontaneously develop diabetes, and insulitis is virtually undetectable. Furthermore, in vitro activated CD4 T cells from GAD 286 TCR transgenic mice express higher levels of CTL-associated antigen (CTLA)-4 than nontransgenic littermates. CD4(+) T cells, or p286-tetramer(+)CD4(+) Tcells, from GAD65 286-300-specific TCR transgenic mice delay diabetes induced in NOD.scid mice by diabetic NOD spleen cells. This data suggests that GAD65 peptide 286-300-specific T cells have disease protective capacity and are not pathogenic.  相似文献   

18.
CD4+CD25+调节性T细胞在恶性肿瘤患者中的应用价值研究   总被引:2,自引:0,他引:2  
目的探讨恶性肿瘤患者外周血CD4 CD25 调节T细胞水平的特点及其临床意义。方法采用流式细胞术检测35例恶性肿瘤患者外周血CD4 CD25 调节T细胞水平及淋巴细胞亚群,并进行分层分析。结果恶性肿瘤患者CD4阳性细胞比例在(I II)期患者即低于对照组,但差异无显著性意义(P>0.05),CD4 /CD8 亦低于对照组,差异有显著性意义(P<0.05),(IIIi、v期)CD4、CD4/CD8阳性细胞比例减低明显,差异有显著性意义(P<0.05);各期CD8、CD3阳性细胞与对照组接近(P>0.05);外周血CD4 CD25 调节T细胞比例在健康对照组为(14.49±4.69)%,恶性肿瘤比例为(19.61±8.17)%。差异有显著性意义(P<0.05);随疾病进展外周血CD4 CD25 T细胞水平升高,在肿瘤(Ⅳ期)尤其明显,统计学有极显著差异(P<0.01)。结论恶性肿瘤患者外周血CD4 CD25 调节T细胞水平的升高,与恶性肿瘤免疫功能低下及肿瘤的发生发展密切相关。  相似文献   

19.
目的验证并探讨CD4+CD25+调节性T细胞及Th17细胞与特发性血小板减少性紫癜发病的关系及可能机制。方法入选自2009年12月至2010年11月在山东省医学科学院附属济宁市第一人民医院血液内科门诊就诊或住院治疗的41例ITP患者(其中初治19例,复发22例,符合难治标准17例)及同期41例健康查体者为研究对象。所有标本均抽取清晨空腹外周血,以肝素钠抗凝。应用流式细胞术(FCM)测定ITP患者和健康对照外周血的CD4+CD25+调节性细胞及Th17细胞百分率;应用酶联免疫吸附试验(ELISA技术)测定ITP患者和健康对照血浆的IL-17水平。结果 ITP病例组外周血CD4+CD25+调节T细胞的百分率明显低于对照组(P〈0.05),而Th17细胞的比例显著高于正常对照组(P〈0.05),血浆IL-17水平在两组间差异无统计学意义(P〉0.05);病例组中初治患者与复发患者外周血CD4+CD25+调节T细胞的百分率比较差异无统计学意义(P〉0.05);难治组患者外周血CD4+CD25+调节T细胞的百分率低于非难治组(P〈0.05);初治患者治疗后外周血CD4+CD25+调节T细胞百分率显著升高,但仍低于正常对照组(P〈0.05)。ITP病例组的CD4+CD25+Treg/Th17较健康对照组明显下降,差异具有统计学意义(P〈0.05)。结论特发性血小板减少性紫癜(ITP)患者外周血CD4+CD25+调节性T细胞显著减少,Th17细胞明显增加,出现Treg/Th17细胞失衡,这可能是影响特发性血小板减少性紫癜发生发展的一个重要因素。ITP患者外周血CD4+CD25+调节性T细胞减少程度在初治与复发ITP患者中差异无统计学意义;难治性ITP可能与CD4+CD25+调节性T细胞数量减少和Treg/Th17失衡尚未纠正有关。初治ITP患者经临床常规治疗后外周血CD4+CD25+调节性T细胞比例回升。  相似文献   

20.
目的 探讨糖尿病合并肺部感染与CD4+CD25+调节性T细胞的关系.方法 用流式细胞仪分别检测健康对照组32例,单纯糖尿病组20例,糖尿病合并肺部感染组23例的CD4+、CD8+、CD4+CD25+T细胞,计算出CD4+/CD8+、CD4+CD25+/CD4+的比值;用统计学方法比较各组T细胞亚群,用因子分析法分析糖尿病合并肺部感染者T细胞亚群等常见因素的内在联系.结果 糖尿病、糖尿病合并肺部感染组CD8+、CD4+CD25+、CD4+CD25+/CD4+比健康对照组高,CD4+、CD4+/CD8+比健康对照组低,且差异有统计学意义;糖尿病合并肺部感染者年龄、病程、CD4+、CD8+、CD4+/CD8+ 、CD4+CD25+ 、CD4+CD25+/CD4+7个指标之间存在中等偏强的内在联系.结论 CD4+ CD25+T细胞升高可能是糖尿病合并肺部感染难治的原因之一,糖尿病合并肺部感染者常见的7项指标之间存在一定的内在联系.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号