自然成熟型树突状细胞对 CD4+CD25+调节性 T细胞扩增的影响

目的：探讨自然成熟型树突状细胞对CD4^＋CD25^＋调节性T细胞扩增机制。方法：提取DAB／2小鼠脾脏及肝脏细胞,流式细胞仪分离树突状细胞,测定其纯度及表型,加入C3H／HeJ小鼠提取的CD4^＋CD25^＋调节性T细胞混合培养,测定其增殖活性。利用CD4^＋CD25-T细胞测定扩增后的CD4^＋CD25^＋调节性T细胞的免疫抑制活性。结果：成熟型树突状细胞表达高水平的共刺激分子CD40、CD80及CD86,对CD4^＋CD25^＋调节性T细胞扩增效果明显。与新鲜分离的CD4^＋CD25^＋调节性T细胞一样,扩增的CD4^＋CD25^＋调节性T细胞高表达Foxp3,而且均保持了其抑制活性。结论：自然成熟型树突状细胞能扩增CD4^＋CD25^＋调节性T细胞,且扩增后的调节性T细胞保持了其表达活性和抑制活性。     

CD4^＋CD25^＋调节性T细胞在肿瘤免疫中的作用研究

CD4^＋CD25^＋调节性T细胞（Treg）在自身免疫耐受、免疫自稳、肿瘤免疫中发挥着重要作用,它可以抑制自身抗原或者非自身抗原如肿瘤抗原引起的免疫反应.人们对Treg细胞的免疫抑制作用已进行了相关的研究和临床应用,最新研究表明其能够诱导肿瘤特异性抗原和局部的免疫反应.此综述将讨论Treg细胞的相关表面分子及其在肿瘤免疫逃逸机制、肿瘤免疫治疗中的研究进展.     

调节性CD4+T细胞在大鼠自发肝移植耐受中的作用

目的 探讨在肝移植的自发耐受模型中，调节性CD4^＋T细胞的免疫抑制作用机制。方法 利用近交系大鼠从Lewis（LEW）到Wistar Furth（WF）的肝移植组合，对移植后不同时期的宿主注射抗CD4的单克隆抗体（Anti-CD4mAb），然后抽血检测丙氨酸氨基转氨酶（ALT）的动态变化；并结合细胞毒性T淋巴细胞（CTL）试验了解宿主脾细胞中T细胞亚群的动态改变。结果 对肝移植自然生存的宿主注射Afiti—CD4mAb后，术后第21天、42天均能够诱导出肝损害（排斥反应），但第56天、100天以上的则未能诱导出来，且该损害能被抗CD8单克隆抗体阻断。另外CTL试验显示宿主的脾细胞中，初始型CTL前体细胞在移植56d后未能检测出来。结论 在自发性肝耐受模型中。宿主术后早期存在由CD4^＋T细胞介导的下调原始效应性T细胞的作用机制。     

CD4+CD25+调节性T细胞/辅助性T细胞17在脓毒症大鼠中的作用

目的 观察CD4+ CD25+调节T细胞(Treg)/辅助性T细胞17(Th17)细胞在脓毒症大鼠炎性免疫反应中的作用.方法 110只雄性SD大鼠随机分为正常对照组、假手术组、脓毒症(CLP)组,采用改良的盲肠结扎穿孔术(CLP)制作大鼠脓毒症模型.采用流式细胞术检测CD14+单核细胞表面人类白细胞抗原-DR基因(HLA-DR)表达率、Treg细胞及TH17细胞比例;酶联免疫吸附试验(ELISA)检测白细胞介素(IL)-6、IL-10、肿瘤坏死因子(TNF)-α、转化生长因子(TGF)-β、白细胞介素(IL)-17炎性因子蛋白表达.结果 与假手术组比较:(1)伴随着脓毒症病情的发展,大鼠出现明显的免疫抑制,CD14+单核细胞HLA-DR表达率＜30％,IL-10/TNF-α比值(27.41 ±7.04比6.63 ±2.60)明显增高(P＜0.01).(2)术后96 h脓毒症大鼠Treg细胞[(11.91±3.88)％比(6.57±2.60)％,P＜0.01]和Th17细胞[(5.14±0.29)％比(2.85±0.07)％,P＜0.01]表达明显增高.(3)术后96 h脓毒症组前炎性细胞因子IL-6[(42.31±15.89) ng/L比(6.32 ±3.18) ng/L,P＜0.01]、IL-10[(69.89 ±20.78) ng/L比(13.58±5.37) ng/L,P＜0.01]、TNF-α[(5.03±3.10) ng/L比(2.77±1.10) ng/L,P＜0.01]、TGF-β[(4.99±2.01) ng/L比(1.88±1.07) ng/L,P＜0.01]、IL-17[(92.77±11.64) ng/L比(7.58±2.30) ng/L,P＜0.01]表达明显增高.结论 伴随着脓毒症病情的发展,大鼠出现明显的免疫抑制;在大鼠脓毒症的发生发展中,Treg细胞介导的免疫抑制及Th17细胞介导免疫激活反应同时存在;脓毒症细胞因子微环境变化可能是导致Treg细胞/Th17细胞失衡的原因之一.     

CD4+CD25+调节性T细胞在肿瘤免疫中的作用研究

CD4+CD25+调节性T细胞(Treg)在自身免疫耐受、免疫自稳、肿瘤免疫中发挥着重要作用,它可以抑制自身抗原或者非自身抗原如肿瘤抗原引起的免疫反应.人们对Treg细胞的免疫抑制作用已进行了相关的研究和临床应用,最新研究表明其能够诱导肿瘤特异性抗原和局部的免疫反应.此综述将讨论Treg细胞的相关表面分子及其在肿瘤免疫...     

性激素与CD4~+CD25~+调节性T细胞的相关性及在肾移植免疫耐受中的作用研究

目的:为明确肾移植术后因供肾、受肾性别差异而排斥反应发生率不同,移植肾存活率不同而进行性激素水平的研究,明确性激素与CD4~+CD25~+调节性T细胞(CD4~+CD25~+Treg)的相关性及在肾移植免疫耐受中的作用。方法:选取正常对照组、肾移植组患者各20例,用ELISA法测定外周血性激素睾酮(T)、雌二醇(E_2)水平,用流式细胞术(FCM)测定CD4~+CD25~+Treg占CD~+T细胞比值。结果:肾移植术后女性E_2水平逐渐由高变低,男性T水平逐渐由低变高,CD~+CD25~+Treg水平也随时间相关性而逐渐升高,以单因素方差分析发现:E_2水平平稳期与正常对照组比较无显著差异(P0.05);T平稳期与正常对照组比较无显著差异(P0.05);肾移植男性受者早期2周内调节T细胞水平与正常值比较有明显差异(P0.05),门诊随访肾移植达2年患者其调节t细胞与正常对照组无明显差异(P0.05)。T与CD4~+CD25~+Treg术后均依时间相关性而逐渐上升,以直线相关性分析发现两者有明显相关性(P0.05)。结论:肾移植术后随着下丘脑-垂体-性腺轴的恢复,患者性激素水平及CD4~+CD25~+Treg水平均逐渐恢复正常。排除体重、年龄、透析时间、HLA配型、缺血时间、术后糖皮质激素、免疫抑制剂治疗方式等因素的影响,T与CD4~+CD25~+Treg有明显相关性,男性在肾移植术后不仅可以通过雄激素直接抑制效应T细胞发挥主要免疫抑制作用,还可以通过增加CD4~+CD25~+Treg水平来发挥次要免疫抑制作用。     

CD4^＋CD25^＋调节性T细胞在维持小鼠肝脏移植自发性免疫耐受状态中的作用

目的 探讨CD4^＋CD25^＋调节性T细胞在维持小鼠肝脏移植免疫耐受状态中的作用。方法 进行小鼠原位肝脏移植,诱导出移植免疫耐受后,向受体注射抗CD25抗体（PC61）以去除CD4^＋CD25^＋T细胞,检测受体内CD4^＋CD25^＋T细胞数量及叉状头／翅膀状螺旋转录因子（Foxp3）的表达以确定CD4^＋CD25^＋T细胞完全被清除,同时观察受体生存时间。结果与同种同系小鼠肝脏移植结果相似,同种异系肝脏移植小鼠的生存时间亦均超过70d。移植免疫耐受诱导后,PC61不同注射方案均能完全去除受体小鼠肝脏、脾脏及血液中的CD4^＋CD25^＋T细胞,且移植肝脏中Foxp3mRNA的表达也明显降低,表明完全去除了CD4^＋CD25。调节性T细胞,但肝脏移植动物生存时间并未受到影响。结论CD4^＋CD25^＋调节性T细胞对于小鼠肝脏移植自发性免疫耐受的维持并非必需。     

CD4+CD25+调节性T细胞与免疫耐受的研究进展

CD4 CD25 调节性T细胞的主要功能是抑制自身反应性T细胞,其在维持机体T细胞内环境稳定,调节和保持对自身抗原耐受之间的平衡以及移植免疫耐受方面具有重要作用。本文主要就CD4 CD25 调节性T细胞的功能、作用机制以及免疫抑制药物对调节性T细胞的影响等研究进展进行综述。     

CD4+CD25+调节性T细胞与免疫耐受的研究进展

CD4＋CD25＋调节性T细胞的主要功能是抑制自身反应性T细胞,对于维持机体T细胞内环境的稳定,调节和保持对自身抗原耐受之间的平衡以及移植免疫耐受具有重要作用。本文主要就CD4＋CD25＋调节性T细胞的功能和作用机制以及免疫抑制药物对其的影响等研究进展进行综述。     

CD4+CD25+调节性T细胞对小鼠肝脏移植自发性免疫耐受的影响

目的 研究CD4+CD25+调节性T细胞在诱导自发性肝脏免疫耐受中的作用.方法 向受体和供体注射抗CD25抗体(PC61)后进行小鼠原位肝脏移植,观测其生存时间.术后20～30 d切取移植肝脏行HE染色,同时观察CD4+CD25+T细胞对CD4+T细胞和CD8+T细胞功能的影响.结果 去除受体而不是供体小鼠的CD4+CD25+T细胞可以导致肝移植排斥反应.而且,去除CD4+CD25+T细胞使移植物的白细胞浸润明显增多,组织损伤加重.同时,去除CD4+CD25+T细胞导致CD4+T细胞的增殖活性和CD8+T细胞的细胞毒活性明显增强.结论 受体来源的CD4+CD25+调节性T细胞在小鼠肝脏移植免疫耐受诱导中起重要作用.

Abstract：

Objective To examine the contribution of CD4+ CD25+ regulatory T cells to liver transplant tolerance. Methods After injection of anti-CD25 monoclonal antibody (mAb, PC61), mouse orthotopic liver transplantation was performed and survivals were determined. The paraffin-embedded sections of hepatic allografts were cut and stained with hematoxylin and eosin (HE). Furthermore, the effect of CD4+ CD25+ regulatory T cells on proliferative response of CD4+ T cells and cytotoxicity of CD8+ T cells was examined by depleting these regulatory T cells. Results Depletion of these cells in the recipients but not in the donors before liver transplantation caused rejection. Histological analyses of hepatic allografts with PC61 treatment showed extensive leukocyte infiltration and tissue destruction, whereas those in the control group showed minimal changes. Moreover, elimination of CD4+CD25+ T cells resulted in the enhancement of both proliferative response of CD4+ T cells and cytotoxicity of CD8+ T cells against donor-type alloantigen. Conclusions These results suggest that CD4+CD25+ regulatory T cells were important for tolerance induction to hepatic allografts.     

The roles of CD25+CD4+ regulatory T cells in operational tolerance after living donor liver transplantation

Recent evidence suggests that CD4+CD25+ regulatory T cells (Tregs) affect immune responses, including those to alloantigens in organ transplants. We have followed a group of liver allograft recipients with good liver graft function who have been weaned off immunosuppression (IS). The purpose of this study was to determine whether Tregs contributed functionally to the mechanisms of graft acceptance. MATERIAL AND METHODS: The functional assay used peripheral blood obtained from LTx recipients free of immunosuppression. The Whole population of CD4+ T cells and the CD4+ T cells depleted of CD4+CD25 high cells were tested for proliferation against donor versus third party stimulators. Moreover to determine the antigen-specificity of the Tregs, serially diluted numbering of CD4+CD25+ T cells were co-cultured with CD4+CD25- T cells. The proliferation responses were examined toward donor versus third party stimulators. RESULT: CD4+ T cells from all LTx recipients off immunosuppression showed hyporesponsiveness to the donor but not to third party stimulators. However, even after depletion of the CD4+CD25 high population, the cells continued to be hyporesponsive toward the donor. In four out of five cases, the suppression exhibited by CD4+CD25+ T cells was more specific for the donor. DISCUSSION: These findings suggest that donor alloantigen specific regulation by Tregs is one of multiple mechanisms that may contribute to the maintenance of liver graft survival in the absence of immunosuppression.     

肝移植急性排斥反应者外周血CD4+CD25+Foxp3+调节性T淋巴细胞的变化

目的 探讨良性终末期肝病患者肝移植术后外周血CD4+CD25+叉状头螺旋转录因子(Foxp3)+调节性T淋巴细胞在急性排斥反应期的变化及意义.方法 2004年12月至2008年1月间,符合入选条件的良性终末期肝病患者共55例,按照术后是否发生急性排斥反应分为排斥组(14例)和无排斥组(41例).肝移植术前用流式细胞仪检测患者外周血CD4+CD25+Foxp3+T淋巴细胞占CD4+T淋巴细胞的百分率(简称CD4+CD25+Foxp3+T细胞百分率),出院后1年内每隔3～6个月复查;发生急性排斥反应时,于治疗前和治疗缓解后(3～6个月)复查.比较两组患者外周血CD4+CD25+Foxp3+T细胞百分率的变化,对排斥组发生急性排斥反应时外周血CD4+CD25+Foxr3+T细胞百分率与排斥反应活动指数(RAI的相关性进行统计学分析.结果 肝移植术前,排斥组与无排斥组外周血CD4+CD25+Foxp3+T细胞百分率的差异无统计学意义(P＞0.05).排斥组患者发生急性排斥反应时外周血CD4+CD25+Foxp3+T细胞百分率为(2.23±0.54)%,低于无排斥组的(2.99±0.86)%,差异有统计学意义(P＜0.01).排斥组中,患者发生急性排斥反应时外周血CD4+CD25+Foxp3+T细胞百分率低于未发生急性排斥反应时的(3.67±0.70)%,差异有统计学意义(P＜0.01).排斥组患者发生急性排斥反应时外周血CD4+CD25+Foxp3+T细胞百分率与RAI呈负相关(r=-0.80,P＜0.01).结论 监测肝移植受者外周血CD4+CD25+Foxp3+调节性T淋巴细胞的变化,可辅助诊断急性排斥反应及判断其严重程度.

Abstract：

Objective To investigate the expression of peripheral blood (PB) CD4+ CD25+ Foxp3+ regulatory T cells (Tregs) in patients with benign end-stage liver disease after liver transplantation and the relationship between levels of PB Tregs and acute rejection. Methods A prospective analysis was performed on 55 consecutive patients who underwent liver transplantation.Fourteen out of 55 cases suffered from acute rejection after liver transplantation were defined as rejection group,while the rest patients were classified into no acute rejection group. PB was obtained from liver transplant patients at different time points longitudinally: pre-transplant, post-transplant within one year and acute rejection. The circulating CD4+ CD25+ Foxp3+ Tregs in PB were measured by flow cytometry. Blood samples were drawn during acute rejection, at the same time, liver biopsies were performed. The circulating CD4+ CD25+ Foxp3+ Tregs were compared between two groups.Results There was no difference between two groups in levels of circulating CD4+ CD25+ Foxp3 + Tregs cells pre-transplant. However, the levels of circulating CD4+ CD25+ Foxp3+ Tregs in rejection group were decreased significantly as compared with no-rejection group (2. 23 % ± 0. 54 % vs. 2. 99 % ±0. 86 %,P＜0.01). The frequency of CD4+ CD25+ Foxp3+ T cells was negatively correlated with rejection activity index (RAI) (r = - 0. 80, P＜0. 01 ). Conclusion Monitoring PB CD4+ CD25+ Foxp3+ Tregs levels may be helpful in evaluating the immune state and act as a more sensitive marker for acute rejection diagnosis in the patients following liver transplantation.     

大黄素对大鼠肝移植后CD4~+CD25~+调节性T细胞的影响

目的研究大黄素对大鼠肝移植后CD4+CD25+调节性T细胞的比例以及对其免疫抑制功能的影响。方法双袖套法建立大鼠原位肝移植模型,以大黄素和环孢素A(CsA)分别在术后腹腔给药,并以给予PBS作为模型对照组,观察不同药物移植后大鼠存活时间的影响,以及对移植术后大鼠外周血中CD4+CD25+调节性T细胞(Tregulatory cells,Treg)亚群的变化以及免疫功能的影响。结果大黄素能显著延长大鼠原位肝移植的术后成活时间,大黄素组大鼠的平均存活时间(17.4±2.5)d与肝移植模型对照组(8.8±1.9)d相比差异具有统计学意义;大鼠肝移植后大黄素给药可显著上调受体大鼠外周血以及肝内CD4+CD25+Treg的比例,并显著增强CD4+CD25+Treg抑制效应性T细胞的增殖能力(P0.05)。结论大黄素能够延长大鼠原位肝移植的术后成活时间,并可能通过上调外周血以及肝内CD4+CD25+Treg的数量及免疫抑制功能来实现移植后免疫排斥反应的抑制。     

信号转导和转录激活因子5在小鼠CD4+CD25+调节性T细胞中的表达

目的:观察信号转导和转录激活因子5(STAT5)在小鼠CD4+CD25+调节性T细胞中的表达情况.方法:免疫磁珠法分离C57BL/6J小鼠脾脏中的CD4+CD25+调节性T细胞,共聚焦荧光法检测细胞内STAT5的分布并进行初步定位,进一步采用Western blot技术从蛋白水平检测细胞内STAT5的表达.结果:激光共...     

Immune regulation by CD4+CD25+ regulatory T cells: implications for transplantation tolerance

In transplantation research, the achievement of life-long tolerance for the graft without the need for immunosuppressive drugs, is a major goal. In the immune system various mechanisms are in place that help to prevent unwanted immunity. These mechanisms of peripheral tolerance include deletion, anergy, ignorance and suppression. In the last decade it has been demonstrated convincingly that a naturally occurring subset of CD4+ T cells, the so-called CD4+CD25+ regulatory T cells, play a key role in the suppression/regulation of immune responses. These cells have been shown to exist in mice, rats and humans, and can be found in thymus, peripheral blood, lymphoid organs and at sites of inflammation. CD4+CD25+ regulatory T cells can down-regulate the immune response by affecting T cell responses, antibody production, cytokine secretion and antigen-presenting cells. CD4+CD25+ regulatory T cells are generated in the thymus, but importantly recent evidence suggests that they can also be generated in the periphery. This latter finding is of particular importance for transplantation immunology, since it suggests that specific manipulation or induction of these cells is achievable in vivo. Here we review the recent developments on the CD4+CD25+ regulatory T cells and we discuss the potential use of these cells in transplantation immunology.     

Decrease of CD4+CD25+ T cells in peripheral blood after liver transplantation: association with immunosuppression

CD25 (IL-2 receptor alpha-chain) marks a population of CD4-positive T cells with a suppressor phenotype. These CD4+CD25+ regulatory T cells can suppress both effector T cells and antigen-presenting cells and have been identified as a principle regulator of tolerance in experimental transplantation models. In the setting of human liver transplantation, however, little is known about the dynamics of these cells in relation to rejection, tolerance, and immunosuppression. In the current study we determined CD4+CD25+ T cell in blood of liver transplant recipients using flow cytometry and investigated a possible link with immunosuppressive therapies. Peripheral blood mononuclear cells (PBMC) of 27 liver transplant patients (pretransplantation and 12 months posttransplantation) and 16 healthy controls were included. We found that the percentages of CD25+ cells within the CD4 T-cell population was significantly reduced in more than two-thirds of patients 1 year after transplantation. Also the total percentage of CD4-positive T cells declined significantly within this period, making the absolute reduction of regulatory T cells after transplantation even more profound. Comparing PBMC samples of patients and healthy controls revealed an increased percentage of CD4+ T cells in the patients before transplantation, probably related to the chronic liver illness. The reduction in CD4+CD25+ T cells after transplantation was similar for different immunosuppression regiments. All patients, however, received calcineurin inhibitors, suggesting a possible suppressive effect of this therapy on regulatory T-cell levels in peripheral blood. Currently, assays for regulatory T-cell activity are used to further support this hypothesis.     

CD4+CD25+FOXP3+T细胞在肝癌肝移植肿瘤复发中的作用

目的 探讨肝癌肝移植病人移植前后外周血和肿瘤组织中CD4+CD25+FOXP3+T细胞比例变化及其临床意义.方法 用流式细胞仪检测肝癌肝移植病人和其他肝移植病人术后外周血中CD4+CD25+FOXP3+T细胞的比例,并采用正常人作对照.用免疫组化法检测肝癌病人和非肝癌病人肿瘤组织中FoxP3的表达及CD8+T细胞浸润的比例.观察肝癌肝移植病人术后及肿瘤复发后调节性T细胞的变化及其对肿瘤复发的影响.结果 流式细胞检测显示肝癌肝移植、非肝癌肝移植的病人术后外周血中CD4+CD25+FOXP3+T细胞占CD4+T细胞的比例较正常人明显升高,分别为(10.15±1.00)%、(5.30±1.64)%和(3.20±1.18)%,P<0.05.肝癌肝移植肿瘤复发病人较未复发病人外周血CD4+CD25+FOXP3+T比例明显升高,分别为(15.15±1.50)%和(6.80±1.50)%,P<0.01.免疫组化检测显示肿瘤组织中FOXP3+T细胞增多,CD8+T细胞浸润明显减少.结论 肝癌肝移植肿瘤复发的病人外周血中CD4+CD25+FOXP3+T细胞比例升高.调节性T细胞可能通过减少CD8+T细胞浸润,加速肿瘤复发.