急性白血病患者CD4+CD25+FoxP3+调节性T细胞、IL-17和IL-23的表达及临床意义

目的观察急性白血病(AL)患者外周血中CD4+CD25+FoxP3+调节性T细胞比例、血清白细胞介素(IL)17和IL-23的表达及其临床意义。方法用流式细胞术测定25例AL患者[急性髓系白血病(AML)15例,急性淋巴细胞白血病(ALL)10例]和10例健康体检者(对照组)外周血中CD4+CD25+FoxP3+调节性T细胞比例,ELISA法测定血清中IL-17和IL-23的表达,分析其间的相关性。结果 AML患者组CD4+CD25+FoxP3+调节性T细胞比例显著高于对照组[(6.52±3.25)vs.(3.58±1.02)](P<0.05);AML和ALL组血清IL-17水平显著高于对照组[(7.21±2.00),(7.47±1.63)vs.(4.52±1.62)](P<0.05)。AL患者血清IL-17和IL-23水平显著正相关(P<0.05)。结论 CD4+CD25+Foxp3+调节性T细胞和IL-17细胞在AML的免疫功能抑制中可能有重要作用,而IL-17细胞在ALL的免疫功能抑制中可能产生作用。     

Reduced function of CD4+25+ regulatory T cell fraction in silicosis patients

The quality and quantity of CD4+25+ regulatory T cells (Treg) in silicosis patients (SIL) were examined and compared with results from healthy donors (HD) because SIL often develop autoimmune diseases along with pulmonary disorders. Peripheral blood mononuclear cells from 57 SIL and 50 HD were analyzed for Treg. Treg frequency and clinical parameters were subjected to a factor analysis. Treg and CD4+25- T cells (Tneg) from five HD and five SIL, sorted by flow-cytometer, were used for functional assays of Treg, the expression pattern of Treg specific genes (FoxP3, GITR and CTLA-4) and activation-related genes (CD122 and CD123). Although the actual frequency of Treg did not differ between SIL and HD, the age-corrected level was reduced in SIL. The factor analysis showed that Treg frequency was positively associated with the serum level of IL-2. The inhibitory effect of Treg on Tneg activation was decreased when the Treg:Tneg ratio was 1:1/4 to 1/2. In addition, Treg dominancy of FoxP3 and CTLA-4 expression and Tneg dominancy of CD132 expression found in HD were lost in SIL. These results indicated that the Treg fraction in SIL may be substituted with chronically activated T cells due to recurrent exposure to silica, resulting in a reduction in the frequency and function of Treg. Since the reduction of Treg may precede the clinical manifestation, as silicosis may be a pre-clinical status for autoimmune diseases, control of Treg function using cell and/or gene therapy may be a good way to manage autoimmune disease.     

Resveratrol induces the suppression of tumor-derived CD4+CD25+ regulatory T cells

CD4+CD25+ regulatory T cells (Treg cells) are negative regulator of the immune system and main obstacles to cancer immunotherapy in tumor-bearing hosts. Resveratrol is a natural product found in grapes with both immunomodulatory and anticancer effects, which can be controlled by Treg cells. Therefore, to determine whether resveratrol performs these actions via Treg cells, we investigated changes in Treg cell population and immunomodulatory cytokines in EG7 tumor-bearing C57BL/6 mice. In the present study, CD4+CD25+ cell population among CD4+ cells was inhibited ex vivo by resveratrol treatment in a dose-dependent manner. FoxP3+ expressing cells among CD4+CD25+ population were significantly reduced after resveratrol treatment ex vivo in intracellular FACS analysis. Single intraperitoneal administration of 4 mg/kg resveratrol suppressed the CD4+CD25+ cell population among CD4+ cells and downregulated secretion of TGF-beta, an immunosuppressive cytokine, measured from the spleens of tumor-bearing mice. Furthermore, resveratrol enhanced IFN-gamma expression in CD8+ T cells both ex vivo and in vivo,leading to immune stimulation. Taken together, these results suggest that resveratrol has a suppressive role on CD4+CD25+ cell population and makes peritumoral microenvironment unfavorable to tumor in tumor-bearing mice. Thus, resveratrol can be considered as possible adjuvant material for vaccination-based cancer therapy.     

Targeting CD4+CD25+FoxP3+ regulatory T-cells for the augmentation of cancer immunotherapy

CD4+CD25+FoxP3+ T-regulatory (Treg) cells are vital to the maintenance of peripheral self tolerance and are implicated in tolerance to foreign antigens. Increasing evidence shows that Treg cells may also play an important role in immune evasion mechanisms employed by cancer. Treg cells are actively recruited and induced by tumors to block innate and adaptive immune priming, effector function and memory response, which can inhibit the efficacy of therapeutic cancer vaccines. As such, modulation of Treg cell function in cancer has been studied using various approaches, with encouraging preclinical and clinical findings. However, controlled and effective modulation of Treg cell function for cancer therapeutics will be contingent on a better understanding of the molecular basis of Treg cell interaction with tumor cells and ensuing immunosuppressive mechanisms.     

Reductive alteration of the regulatory function of the CD4(+)CD25(+) T cell fraction in silicosis patients

Causal links have been documented between silica and rheumatoid arthritis, lupus erythematosus, systemic sclerosis and glomerulonephritis. Two different effects of silica have been suggested, an enhanced inflammatory response in the pulmonary region (e.g. activation of alveolar macrophages) and dysregulation of autoimmunity. Based on our previous reports showing in vitro activation of peripheral T cells by silica and reduced regulatory function of the peripheral CD4(+)CD25(+) fraction in which FoxP(3)+ regulatory T cells (Treg) are located, reconstitution of the CD4(+)CD25(+) fraction in silicosis patients (SILs) was investigated. Since T cells in peripheral CD4(+)CD25(+) and CD4(+)CD25(-) (effector T cells; Teff) fractions from SILs showed higher expression of pd-1 (a marker gene for T cell activation) in comparison to that of healthy donors (HDs), chronic T cell activation was considered to have occurred in SILs. In this study, a higher expression of the CD95/Fas molecule in Treg was recorded from silicosis patients (SILs) compared to healthy donors (HDs), and excess loss of FoxP3(+) Treg in freshly isolated peripheral blood mononuclear cells (PBMCs) from SILs relative to HDs was demonstrated when these cells were cultured with silica ex vivo, whereas CD25(+) cells were not reduced due to contamination of activated Teff in the CD4(+)CD25(+) fraction. The activation of both Teff and Treg results in reconstitution of the peripheral CD4(+)CD25(+) fraction, loss of Treg and contamination of activated Teff, resulting in reduction of the number and function of Treg. These results contribute to our understanding of the development of autoimmune diseases found in SILs.     

In-vitro generation and characterisation of murine CD4+CD25+ regulatory T cells with indirect allospecificity

Naturally arising CD4(+)CD25(+) regulatory T cells play a pivotal role in the prevention of autoimmunity and in the induction of donor-specific transplantation tolerance. Harnessing regulatory cells for potential adoptive cell therapy is hampered by their lack of antigen-specificity and their limited numbers. Here we describe the generation and expansion of murine CD4(+)CD25(+) T cells with antigen-specificity for an K(d) peptide as potential reagents for adoptive cell therapy in promoting donor-specific transplantation tolerance. Using bone marrow-derived autologous dendritic cells pulsed with the K(d) peptide, we generated T cell lines from purified CD4(+)CD25(+) T cells from C56BL/6 mice. The T cell lines expressed high level of CD25 and low level of CD45RB and CD69. They maintained the expression of CD62L, GITR, CTLA-4 and more importantly FoxP3. The CD4(+)CD25(+) T cell lines were anergic after TCR stimulation and produced little cytokine such as IL-2 and IFN-gamma. Importantly, they were more potent than freshly isolated CD4(+)CD25(+) T cells in suppressing proliferation and cytokine secretion by effector CD4(+) T cells. Furthermore, the CD4(+)CD25(+) T cell lines could be expanded to large cell numbers and maintained in culture up to 1 year. The K(d)-specific CD4(+)CD25(+) T cell lines will be invaluable in devising a strategy for the induction of cardiac transplantation tolerance in wild-type B6 mice carrying a full mismatch BALB/c heart.     

CD4+CD25+ regulatory T cells in health and disease

1. Over the past 5 years, tremendous progress has been made in understanding the suppressive mechanisms of T regulatory (Treg) cells. The Treg cells, a subpopulation of T cells, have been shown to play an important role in maintaining peripheral tolerance and the prevention of autoimmunity. 2. Various populations of Treg cells have been described, including thymically derived CD4(+)CD25(+) Treg cells. These naturally occurring Treg cells are present in the periphery and are capable of suppressing proliferation and effector T cell responses both in vitro and in vivo. 3. In addition, a second subset of Treg cells, type 1 T regulatoary (Tr1) and Th3 cells, exert their suppressive capacity via cytokines such as interleukin-10 and transforming growth factor-beta and are contact independent. 4. The present review summarizes the characteristics and molecular basis of CD4(+)CD25(+) Treg cells, as well as their therapeutic potential in modulating inflammatory diseases, such as inflammatory bowel disease and rheumatoid arthritis.     

肝癌肝移植术后西罗莫司转换治疗的免疫学效应分析

目的 探讨以西罗莫司为主的联合免疫治疗方案(SCTR)对肝癌肝移植受者体内调节性T细胞(Treg)和效应性T细胞表达的影响.方法 对2010年1月-2015年6月收治的应用SCTR干预的肝癌肝移植28例的临床资料进行回顾性分析,观察术后不同时间点CD3、CD8+的表达,并对其与Treg的表达进行相关性分析.结果 SCTR干预下,肝癌肝移植受者术后12个月内,FoxP3+ Treg的比例从术前峰值降低到术后1个月谷值,随后逐渐升高,3个月时在正常值水平(P＞0.05),术后12 ～ 18个月水平逐步维持在较低水平,与正常水平比较差异有统计学意义(P＜0.05).术前、术后12和18个月FoxP3+ Treg和CD3、CD8+T淋巴细胞的变化呈反向趋势.FoxP3+ Treg与CD3和CD8的表达水平呈负相关(r=-6.37、-7.12,P＜0.001).肝癌肝移植术后白介素-10、p型转化生长因子和甲胎蛋白水平均较术前显著降低(P＜0.05),且其变化与Treg呈正相关.结论 SCTR可降低肝癌肝移植术后FoxP3+ Treg、IL-10、TGF-β的表达,并不增加排斥反应,临床应用安全、有效.     

TF3-H4对CD4~+CD25~+调节性T细胞和CD4~+CD25~-效应性T细胞早期活化的影响

目的观察1',2',3',7'-四氢茶黄素-3,3'-双没食子酸酯(TF3-H4)对CD4+CD25+调节性T细胞和CD4+CD25-效应性T细胞早期活化的影响,分析TF3-H4对两群功能相反的CD4+T细胞的作用。方法免疫磁珠分离BALB/c小鼠脾脏CD4+CD25+调节性T细胞和CD4+CD25-效应性T细胞,加入ConA或PDB,和TF3-H4共同孵育12 h后收集细胞,流式细胞仪分析细胞表面早期活化标志CD69的表达。结果在ConA和PDB的作用下,两群细胞早期活化标志CD69的表达均升高。TF3-H4(20 mg.L-1)不能抑制PKC激动剂PDB激活的CD4+CD25-效应性T细胞CD69的表达,却能抑制ConA激活的CD4+CD25-效应性T细胞CD69表达;同时,TF3-H4也能明显抑制ConA激活的CD4+CD25+调节性T细胞的CD69表达。结论茶黄素衍生物TF3-H4可能经由TCR活化途径的上游抑制CD4+CD25-效应性T细胞活化;TF3-H4对CD4+CD25+调节性T细胞和CD4+CD25-效应性T细胞早期活化的抑制作用,可能是该类化合物发挥抗炎、抗肿瘤作用的机制之一。     

TCR peptide vaccination in multiple sclerosis: boosting a deficient natural regulatory network that may involve TCR-specific CD4+CD25+ Treg cells

Vaccination with self peptides contained within T cell receptor (TCR) chains, expressed by pathogenic Th1 cells can induce a second set of regulatory T cells that can reverse paralysis in rodents with experimental encephalomyelitis, and similarly, may have the potential to regulate myelin-reactive Th1 cells in patients with multiple sclerosis (MS). In this review, we discuss our recent discovery that TCR-reactive T cells generally possess classical inhibitory activity associated with Treg cells. CD4+CD25+ TCR-reactive T cells can inhibit CD4+CD25- indicator cells stimulated with anti-CD3/anti-CD28 antibody in a dose-dependent and cell-contact-dependent manner. Additionally, CD4+CD25+ T cells from blood of healthy control donors have significant responses to a pool of discriminatory TCR peptides, including BV10S1P, BV19S20, BV13S7, BV12S2A2T, BV11S1A1T, BV21S3A1T, AV15S1, and BV12S1A1N1. Patients with MS have varying degrees of deficient responses to TCR peptides, and by association, a defect in Treg cell function as well. TCR peptide vaccination using a new tripeptide mixture emulsified in IFA produced strong T cell responses in 100% of MS recipients, a dramatic improvement over previous vaccines given i.d. in saline that induced TCR-reactive T cell responses in about 50% of recipients. Responders to vaccination had a tendency towards reduced MRI lesions, and an early indication of enhanced Treg activity mediated by TCR-reactive T cells that could provide suppression of target as well as bystander T cells. These data provide a strong foundation for future TCR vaccination studies that will critically test the ability of the tripeptide mixture to induce significantly enhanced Treg activity and possible clinical and MRI benefits in vivo.     

Peripheral CD4+ CD25+ Treg cell expansion in lung transplant recipients is not affected by calcineurin inhibitors

CD4+CD25+ regulatory T (Treg) cells have been shown to play a role in allograft tolerance and their peripheral counts vary according to the degree of graft acceptance in lung transplant recipients (LTR). Recent studies demonstrate that certain drugs might modulate generation, expansion and activity of Treg cells. Aim of this study was to evaluate the effect of therapeutic regimens used in our institution on peripheral CD4+CD25(high)CD69- Treg cell numbers in a group of 51 LTR with stable clinical conditions. They were treated with standard immunosuppression: calcineurin inhibitor (CNI)+azathioprine (AZA)+steroids (n=28) or with CNI+mycophenolate mofetil (MMF)+steroids (n=11) or with CNI+steroids (n=12). These stable LTR were compared with age-matched healthy controls (n=35) and with 19 LTR who developed bronchiolitis obliterans syndrome (BOS) and were treated analogously. Stable LTR showed higher peripheral Treg cell counts with respect to age-matched healthy controls (59.9+/-31.8/mul versus 42.1+/-16.9/mul, respectively; p<0.05). This increase was detectable in all patients treated with CNI either in association with AZA or MMF. During these treatments a significant expansion of Treg cell counts was detectable during acute rejection (AR) episodes (86.03+/-26.6/mul during AR versus 36.34+/-7.6 before AR; p<0,05). Moreover, the development of BOS was associated to a significant decrease of Treg cell counts irrespective to the immunosuppressive regimen used. In conclusion, therapeutic regimens based on CNI seem to allow a certain degree of peripheral Treg cell expansion in stable LTR.     

Differential effect of sodium arsenite during the activation of human CD4+ and CD8+ T lymphocytes

Contamination of water with arsenic is a problem affecting several regions of the world. Peripheral blood mononuclear cells (PBMC) from chronically exposed individuals show a lower replicating activity than non-exposed individuals when stimulated with phytohemagglutinin (PHA). We have previously reported that PBMC from healthy donors treated in vitro with 1 muM sodium arsenite (NaAsO2) and stimulated with PHA showed a reduction in proliferation by a delay in cell cycle entry and a decrease in the rounds of cell division. In this paper we tested the effect of 1-5 muM NaAsO2 on the proliferation, viability, blast transformation, expression of the CD4 and CD8 molecules, and during the activation and proliferation of both CD4+ and CD8+ T lymphocytes. We found a reduction in cell proliferation and an increase in non-dividing cells with higher concentrations of NaAsO2 (2-5 microM) when proliferation was studied by 5,6-carboxyfluorescein diacetate succinimidyl ester (CFSE) dilution. The use of 7-aminoactinomycin D (7-AAD) in CFSE-labeled cells allowed us to detect an increase in percentage of non-dividing cells, and an increase in apoptotic/dead cells mainly in non-proliferating cells. Analysis of the expression of CD4 and CD8 molecules on these cells showed that concentrations > or = 2 microM NaAsO2 reduced the expression of the CD8 molecule and induced apoptosis/death in CD4+ cells. Analysis of blast transformation by flow cytometry showed an accumulation of CD8+ resting cells in the presence of NaAsO2. Analysis of CD25 and CD69 expression in kinetics experiments in both subtypes showed a delay in the expression of CD25 and a delay in the downregulation of the CD69 molecule, in both CD4+ and CD8+ cells. However, in the case of CD8+ cells, we detected an accumulation of a CD25- CD69- population in the presence of increasing concentrations of NaAsO2. Altogether, our results show that NaAsO2 alters the expression kinetics of the early activation molecules CD25 and CD69 similarly in both subtypes. In addition, activated and non-activated CD4+ cells die by apoptotic mechanisms and although a percentage of CD8+ cells also die by apoptosis, a subpopulation of these cells is unable to activate and thus accumulates as resting cells.     

CD4+CD25+调节性T细胞及Th17细胞与Graves病机制研究

目的：探讨CD4+CD25+调节性T细胞以及Th17细胞与Graves病的关系。方法：检测GD患者和对照组外周血单个核细胞CD4+CD25+Tregs、Th17细胞的数量,PBMC中TGF-β、IL-10和FoxP3 mRNA的表达水平以及血清TGF-β、IL-10和IL-17水平。结果：GD组外周血Th17数量高于对照组,血清中IL-17水平也高于对照组（P＜0.05）;而CD4+CD25+Tregs的数量低于对照组,而且TGF-β、FoxP3表达水平低于对照组（P＜0.05）;GD组血清中TGF-β、IL-10水平高于对照组（P＜0.05）。结论：CD4+CD25+Tregs数量的减少或功能障碍以及Th17细胞数量的升高,可能参与GD的发病过程。     

薏苡仁酯对高龄恶性肿瘤患者Treg细胞的影响

目的探讨薏苡仁酯(coixenolide)对高龄恶性肿瘤患者外周血调节性T细胞(Treg)的作用。方法检测30例80岁以上老年恶性肿瘤患者(肿瘤组)薏苡仁酯治疗前后外周血Treg占总CD4+T细胞比例和血IL-2mRNA变化。结果与30例健康老年人(对照组)进行比较。结果肿瘤组外周Treg占总CD4+T细胞比例、血IL-2mRNA水平均明显高于对照组(P<0.01)。肿瘤组外周血Treg比例与血IL-2mRNA水平呈正相关(r=0.921,P<0.01)。肿瘤组在薏苡仁酯治疗2个周期后,外周血Treg、IL-2mRNA水平较治疗前明显下降(P<0.01)。结论薏苡仁酯可能通过下调IL-2分泌和Treg数目解除免疫抑制而发挥抗肿瘤作用。     

调节性T淋巴细胞在HCV感染者病程不同阶段的表达

目的探讨CD4+CD25+调节性T细胞(Treg)在HCV感染者病程不同阶段的表达及其意义。方法收集非活动性HCV感染33例(A组)、活动性HCV感染32例(B组)、慢性丙型肝炎56例(C组)、HCV相关性肝硬化47例(D组)、HCV相关性肝癌45例(E组)和健康对照者60例(F组),采用流式细胞术检测外周血CD4+T细胞中CD4+CD25+Treg的表达频率,并进行统计学分析。结果 B、C、D、E组外周血CD4+T细胞中CD4+CD25+Treg的表达频率均明显高于F组(P<0.01)。组间比较,A组患者外周血的CD4+CD25+Treg细胞表达频率明显低于B、C、D、E组(P<0.01),D、E组表达频率明显高于B、C组(P<0.01)。结论 HCV感染导致CD4+CD25+Treg细胞的增殖与活化,使机体对其的免疫清除不完全,从而促进HCV感染者疾病的进展和肝癌的发生。     

外用他克莫司对寻常型银屑病患者CD4^＋CD25^＋调节性T细胞的影响

目的 探讨外用他克莫司对寻常型银屑病患者外周血CD4^＋CD25^＋调节性T细胞（CD4^＋CD25^＋Treg）的影响.方法 给予48例寻常型银屑病患者他克莫司软膏,每日2次外用,用药8周.治疗前和治疗后,用流式细胞仪检测患者外周血CD4^＋CD25^＋调节性T细胞的表达水平,并对患者进行PASI评分.结果 治疗8周后,总有效率为91.5%.治疗前,银屑病进行期、静止期患者及正常人外周血CD4^＋CD25^＋Treg与CD4＋淋巴细胞的百分比为（2.64±0.86）%、（3.98±0.96）%、（8.46±1.54）%,三者比较,差异均有极显著性（P＜0.01）;治疗后,进行期和静止期患者外周CD4^＋CD25^＋Treg与CD4＋淋巴细胞的百分比较治疗前均有明显升高（P＜0.01）,但仍低于正常人,三者比较,差异均有极显著性（P＜0.01）.结论 寻常型银屑病存在CD4^＋CD25^＋调节性T细胞异常,他克莫司可通过上调CD4^＋CD25^＋调节性T细胞来治疗寻常型银屑病.     

Low-dose of tacrolimus favors the induction of functional CD4+CD25+FoxP3+ regulatory T cells in solid-organ transplantation

It has been reported that low-dose of tacrolimus (Tac) is advantageous for the long-term allograft function and survival when compared with standard-dose of tacrolimus. However, the underlying mechanism is not known and remains to be elucidated. CD4⁺CD25⁺FoxP3⁺ regulatory T cells (Tregs) play a key role in the induction and maintenance of transplantation tolerance. We studied whether low-dose of Tac would favor the induction of donor-specific Tregs. We found that in all transplant recipients treated with low-dose of Tac (target trough level of 3 to 7 ng/ml), CD4⁺CD25⁺FoxP3⁺ Tregs were induced and expanded in the periphery and accumulated in the allograft after transplantation, and they retained their suppressive efficacy in vitro. When studied in vitro, we found that high concentration of Tac significantly decreased the induction of FoxP3 expression in mixed lymphocyte reactions (MLR) when compared with low concentration of Tac. Taken together, these data imply that in solid-organ transplantation the minimization of Tac might be beneficial and favors the induction of donor-specific Tregs maintaining transplantation tolerance to alloantigen.     

CD4~+CD25~+调节性T细胞在不同肝脏肿瘤中的表达及意义

目的:研究CD4+CD25+调节性T细胞(Treg)在不同肝脏肿瘤中的分布特点,评价其在肿瘤发生和发展中的作用.方法:根据病理诊断结果将80例肝脏肿瘤分为肝局灶性结节状增生(FNH)组10例、不典型腺瘤样增生(AAH)组10例以及原发性肝癌(HCC)组60例.另选取10例正常肝组织(肝血管瘤边缘肝组织)石蜡包埋标本为对照组.采用双重酶标免疫组化染色的方法测定不同肝脏肿瘤切片中Treg细胞的表达状况.对比分析Treg细胞在FNH、AAH和HCC各组中的表达特点,并进一步分析在HCC组中Treg细胞表达的影响因素.结果:对照组及FNH组中均未发现Treg细胞的表达.AAH组、HCC组中有Treg细胞的表达,且HCC组较AAH组增多(P＜0.01).在癌旁组织中已有Treg 细胞浸润,但较肝癌组织中Treg细胞数量少(P＜0.01).肝癌组织中不同患者性别、年龄、术前AFP水平的Treg细胞数量差异无统计学意义,而在不同肿瘤大小、肿瘤包膜是否完整及术前HBV-DNA水平是否升高中Treg细胞数量差异有统计学意义(P＜0.05或P＜0.01).结论:Treg细胞的表达与肿瘤的发生和发展有关,在肿瘤免疫中起负调节作用.