An MHC-linked locus modulates thymic differentiation of CD4+CD25+Foxp3+ regulatory T lymphocytes

CD4+CD25+Foxp3+ regulatory T lymphocytes are crucial for maintenance of immunological tolerance to self and innocuous non-self, are known to modulate immunity to tumors and infectious agents and can induce transplantation tolerance. Surprisingly, only a single genetic polymorphism is known to modulate regulatory T cell (Treg) development in the thymus, leading to a lethal autoimmune disorder. Here, we show that considerably different levels of Tregs are found in the thymi of distinct common laboratory mouse strains. We demonstrate that distinct levels of phenotypically and functionally identical Tregs develop with similar kinetics in the studied mice, that the responsible locus acts in a thymocyte-intrinsic manner and that levels of thymic Foxp3+ Tregs correlate to those found in the periphery. Using several congenic mouse strains, we mapped one of the at least two genetic loci capable of quantitatively modulating thymic Treg development to a 相似文献   

Recovery from experimental allergic encephalomyelitis is TGF-beta dependent and associated with increases in CD4+LAP+ and CD4+CD25+ T cells

SJL mice are highly susceptible to proteolipid protein (PLP) 139-151-induced experimental allergic encephalomyelitis (EAE). The disease is characterized by a relapsing-remitting type of paralysis. However, the mechanism by which animals recover from EAE is poorly understood. Here, we investigated the role of regulatory T cells in the recovery from disease. We found that Forkhead box P3-expressing CD4+CD25+ T cells were increased in the blood, draining lymph node and spleen of EAE-recovered SJL mice. These cells were anergic and inhibited proliferation of CD4+CD25- T cells to PLP 139-151 or anti-CD3 antibody stimulation. Depletion of CD4+CD25+ T cells during the recovery phase exacerbated disease, resulted in the expansion of IA(s)/PLP 139-151-tetramer-positive cells and enhanced IFN-gamma production. In addition, transforming growth factor-beta (TGF-beta) was shown to be involved in the recovery from EAE as the percentage of CD4+ cells expressing TGF-beta latency-associated peptide (LAP) on the cell surface increased significantly in blood and spleen of EAE-recovered mice as compared with the naive mice and in vivo neutralization of TGF-beta abolished recovery from disease. Taken together, our results demonstrate that both CD4+CD25+ and CD4+LAP+ regulatory T cells mediate recovery from PLP 139-151-induced EAE in SJL mice in which TGF-beta plays an important role.     

Imbalance of Different Types of CD4+Foxp3+ T cells in renal transplant recipients

Aims: To determine the number of CD4⁺CD25^-Foxp3⁺, CD4⁺CD25⁺Foxp3⁺ and CD4⁺CXCR5⁺Foxp3⁺ T cells in renal transplant recipients that are transplanted stable (TS), or experiencing accelerated rejection (ALR), or acute rejection (AR).

Methods: Renal transplantation was conducted in 28 patients with end-stage renal failure (ESRF). The number of peripheral CD4⁺CD25^-Foxp3⁺, CD4⁺CD25⁺Foxp3⁺, or CD4⁺CXCR5⁺Foxp3⁺ T cells and the serum levels of interleukin-10 (IL-10) were measured in pre- and post-transplant patients and these results were compared to 10 healthy controls (HC). Correlation between CD4⁺CD25⁺Foxp3⁺ and estimated glomerular filtration rate (eGFR), CD4⁺CD25^-Foxp3⁺ and serum creatinine (Cr) levels, or Cr and IL-10 levels in TS patients was also determined.

Results: The number of CD4⁺CD25^-Foxp3⁺ T cells was significantly increased in patients with ESRF, as compared to HC. Stratification analysis demonstrated that TS patients contained greater numbers of CD4⁺CD25⁺Foxp3⁺ and CD4⁺CXCR5⁺Foxp3⁺ T cells, higher levels of serum IL-10, and fewer numbers of CD4⁺CD25^-Foxp3⁺ T cells than ESRF patients. In contrast, ALR and AR patients contained fewer numbers of CD4⁺CD25⁺Foxp3⁺ and CD4⁺CXCR5⁺Foxp3⁺ T cells, greater numbers of CD4⁺CD25^-Foxp3⁺ T cells, and lower levels of serum IL-10 than ESRF patients. In TS patients, the numbers of CD4⁺CD25⁺Foxp3⁺ and CD4⁺CD25^-Foxp3⁺ T cells were positively correlated with eGFR and serum Cr levels, respectively.

Conclusion: An imbalance of different types of CD4⁺Foxp3⁺ T cells might be involved in renal transplant rejection.     

CD4+CD25+T细胞在系统性红斑狼疮中的表达及意义

目的：探讨CD4^＋ CD25^＋ T细胞、IL-10在系统性红斑狼疮（SLE）患者外周血的表达及临床意义。方法：入组30例SLE患者和20例正常对照者，其中活动性SLE患者17人，非活动性SLE患者13人。用流式细胞仪检测SLE患者和正常对照者的外周血CD4^＋ CD25^＋ T细胞阳性率，用酶联免疫吸附试验（ELISA）检测血清中IL-10浓度。结果：活动性和非活动性SLE患者CD4^＋ T细胞总数均低于正常对照者；活动性和非活动性SLE患者CD4^＋ CD25^＋ T细胞阳性率高于正常对照者；活动性SLE患者IL-10浓度显著高于非活动性SLE患者和正常对照者。SLE患者CD4^＋ CD25^＋ T细胞阳性率和血清IL-10浓度与补体C3、抗DNA抗体水平及SLEDAI积分均无相关性。结论：SLE患者外周血CD4^＋ CD25^＋ T细胞是活化T细胞的标志，IL-10分泌异常与SLE的发病有关。     

卡介苗多糖核酸对哮喘大鼠淋巴液和血液CD4~+CD25~+Foxp3~+调节性T细胞的影响

目的:探讨卡介苗多糖核酸(BCG-PSN)对哮喘大鼠淋巴液和血液调节性T细胞数量及功能的影响。方法:将SD大鼠随机分为对照组、哮喘组和BCG-PSN组,分别收集不同时间点大鼠淋巴液和血液,采用流式细胞仪(FCM)检测CD4+CD25+Foxp3+调节性T细胞(CD4+CD25+Foxp3+Treg)百分率,酶联免疫吸附试验(ELISA)检测淋巴液和血浆白介素10(IL-10)和转录生长因子β1(TGF-β1)浓度。结果:各组在各时间点其淋巴液中CD4+CD25+Foxp3+Treg百分率、IL-10水平均较血液明显升高。哮喘组大鼠淋巴液和血液中CD4+CD25+Foxp3+Treg百分率、IL-10、TGF-β1浓度均较对照组显著降低(P0.05)。BCG-PSN组淋巴液和血液中CD4+CD25+Foxp3+Treg百分率和IL-10水平较哮喘组明显升高(P0.05),与对照组比较无显著性差异;而TGF-β水平在48小时较对照组和哮喘组明显升高(P0.05)。结论:哮喘大鼠淋巴液和血液存在明显CD4+CD25+Foxp3+Treg数量及功能不足。BCG-PSN可能通过增加哮喘大鼠外周血和淋巴液中CD4+CD25+Foxp3+Treg的数量及其产生IL-10和TGF-β水平,增强免疫抑制效应,从而发挥抑制哮喘炎症的作用。     

不同结核病患者CD4+CD25+Foxp3+调节性T细胞表达的变化

Objective To investigate the expression of CD4 + CD25 + Foxp3 + regulatory T cell in patients with tuberculosis, and to discover its role in the immune response to mycobacterium tuberculosis. Methods Thirty-three patients with tuberculosis and 30 healthy controls were selected who were consulted in our hospital. Patients were classified by their chemotherapy and smear sputum and CD4 + CD25 + Foxp3 + regulatory T cell were detected by flow cytometry. Results Expression of CD4 + CD25high and CD4+ CD25 + Foxp3 + regulatory T cell in experimental group were ( 8.84 ± 2.55 ) % and (6.30 ± 1.38 ) % respectively, which were significantly higher than they were in control group (t = 3.57,4. 01, P ＜ 0. 01 ). The expression of CD4 + CD25high and CD4+ CD25 + Foxp3 + regulatory T cell in patients with positive smear sputum were also significant higher than that in patients with negative smear sputum ( t = 2. 51,2. 42,P ＜ 0.05). No significance was founded between the first-visit group and revisit group ( t = 0. 03, 0. 02, P ＞ 0.05 ). Conclusions CD4 + CD25high and CD4 + CD25 + Foxp3 + regulatory T cell in patients with tuberculosis were higher than healthy control, which may result in immune suppression.     

Galectin‐3 negatively regulates the frequency and function of CD4+CD25+Foxp3+ regulatory T cells and influences the course of Leishmania major infection

Galectin‐3, an endogenous glycan‐binding protein, plays essential roles during microbial infection by modulating innate and adaptive immunity. However, the role of galectin‐3 within the CD4⁺CD25⁺Foxp3⁺ T regulatory (T_REG) cell compartment has not yet been explored. Here, we found, in a model of Leishmania major infection, that galectin‐3 deficiency increases the frequency of peripheral T_REG cells both in draining lymph nodes (LNs) and sites of infection. These observations correlated with an increased severity of the disease, as shown by increased footpad swelling and parasite burden. Galectin‐3‐deficient (Lgals3^?/?) T_REG cells displayed higher CD103 expression, showed greater suppressive capacity, and synthesized higher amounts of IL‐10 compared with their wild‐type (WT) counterpart. Furthermore, both T_REG cells and T effector (T_EFF) cells from Lgals3^?/? mice showed higher expression of Notch1 and the Notch target gene Hes‐1. Interestingly, Notch signaling components were also altered in both T_REG and T_EFF cells from uninfected Lgals3^?/? mice. Thus, endogenous galectin‐3 regulates the frequency and function of CD4⁺CD25⁺Foxp3⁺ T_REG cells and alters the course of L. major infection.     

CTLA-4 x Ig converts naive CD4+CD25- T cells into CD4+CD25+ regulatory T cells

CTLA-4 x Ig was originally designed as an immunosuppressive agent capable of interfering with the co-stimulation of T cells. In the present study, we demonstrate that CTLA-4 x Ig, in combination with TCR ligation, has the additional capacity to convert naive CD4+CD25- T cells into Foxp3+ regulatory T (T(reg)) cells, as well as to expand their numbers. The CD4+CD25+Foxp3+ T(reg) generated by CTLA-4 x Ig treatment in vitro potently suppress effector T cells. Extending this in vivo, we show that systemic administration of CTLA-4 x Ig increases the percentage of CD4+CD25(hi)Foxp3+ cells within mixed lymphocyte reaction-induced murine lymph nodes. Significantly, the in vitro conversion of naive CD4+CD25- T cells into T(reg) cells is antigen-presenting cell (APC) dependent. This finding, together with the further observation that this conversion can also be driven in vitro by an antibody that engages B7-2 ligand, suggests that CTLA-4 x Ig-driven T(reg) induction may be predicated upon active CTLA-4 x Ig to B7-2 signaling within APC, which elicits from them T(reg)-inducing potential. These findings extend CTLA-4 x Ig's functional repertoire, and at the same time, reinforce the concept that T cell anergy and active suppression are not entirely distinct processes and may be linked by some common molecular triggers.     

Normal human pregnancy is associated with an elevation in the immune suppressive CD25+ CD4+ regulatory T-cell subset

Summary CD4+ CD25+ T regulatory cells (TReg), suppress antigen-specific immune responses and are important for allograft tolerance. During pregnancy the mother tolerates an allograft expressing paternal antigens (the fetus) requiring substantial changes in immune regulation over a programmed period of time. We analysed whether immune-suppressive TReg cells were altered during pregnancy and therefore might play a part in this tolerant state. The presence of TReg cells was assessed in the blood of 25 non-pregnant, 63 pregnant and seven postnatal healthy women by flow cytometry. We observed an increase in circulating TReg cells during early pregnancy, peaking during the second trimester and then a decline postpartum. Isolated CD25+ CD4+ cells expressed FoxP3 messenger RNA, a marker of TReg cells, and suppressed proliferative responses of autologous CD4+ CD25- T cells to allogeneic dendritic cells. These data support the concept that normal pregnancy is associated with an elevation in the number of TReg cells which may be important in maintaining materno-fetal tolerance.     

Deficiency of Mouse CD4~+CD25~+Foxp3~+ Regulatory T Cells in Xenogeneic Pig Thymus-Grafted Nude Mice Suffering from Autoimmune Diseases

Xenogeneic thymus transplantation can efficiently induce specific immune tolerance to donor antigens in athymic recipients.However,many nude mice snffer from autoimmune diseases(AID) for over 10 weeks after xenogeneic thymus transplantation.CD4 CD25 Foxp3 regulatory T (Treg)cells were recently determined to play a pivotal role in keeping immune tolerance in humans and mice.Thus,we investigated this subpopulation of Treg cells in the periphery of pig thymus-grafted nude mice suffering from AID.Our results showed that the expression of Foxp3, CTLA-4 and GITR on mouse CD4 CD25 T cells and the ratio of CD4 CD25 Foxp3 Treg cells to CD4 T cells were significantly decreased in the periphery of pig thymus-grafted nude mice snfiering from AID,compared with healthy pig or mouse thymus-grafted nude mice.Furthermore,mouse CD4 CD25 T cells in pig thymus-grafted nude mice Sufiering from AID showed more severe deficiency in immunosuppressive function compared with the counterpart in xenogeneic pig or syngeneic thymus-grafted nude mice without AID.Thus,the decreased frequency, altered phenotype and functional deficiency of mouse CD4 CD25 Treg cells in pig thymus-grafted nude mice may contribute to the development of AID in this model.     

小鼠CD4~+ CD25~+ Foxp3~+调节性T细胞体外扩增

目的:本研究旨在探讨CD4+CD25+Foxp3+调节性T细胞体外扩增的方法。方法:采用磁珠分选小鼠CD4+T细胞,αCD3单克隆抗体包被24孔板,加入αCD28单克隆抗体、雷帕霉素、rhIL-2,培养3周后,流式细胞仪测定培养细胞中CD4+CD25+T细胞的含量,实时定量PCR检测CD4+CD25+T细胞Foxp3 mRNA的表达;单向混合淋巴细胞反应和增殖抑制试验测定扩增的CD4+CD25+T细胞的增殖及其抑制功能;ELISA检测培养上清中IL-10和TGF-β1的含量。结果:小鼠CD4+T细胞培养3周后,CD4+CD25+T细胞达(76.05±2.73)%,高于未加雷帕霉素组(52.17±1.36)%(P<0.001),磁珠分选的CD4+CD25+T细胞Foxp3 mRNA的表达是未加雷帕霉素组的5倍(P<0.001),增殖能力是未加雷帕霉素组的0.29倍(P<0.001),对CD4+T细胞增殖抑制能力是未加雷帕霉素组的3.6倍(P<0.001),培养上清中IL-10和TGF-β1分别是对照组的1.8倍和1.6倍(P<0.001)。结论:小鼠CD4+T细胞在含有1μg/ml的αCD28、rhIL-2 100 U/ml和终浓度为10 nmol/L雷帕霉素的培养体系中培养3周后能有效扩增CD4+CD25+Foxp3+调节性T细胞。     

Foxp3逆转录病毒载体的构建及其诱导的CD4+CD25+Foxp3+T细胞免疫抑制功能研究

Foxp3基因的表达与CD4+CD25+免疫调节细胞的功能密切相关。为在体外诱导具有免疫调节功能的CD4+CD25+免疫调节细胞,本文构建了带有绿色荧光蛋白(eGFP)的pMSCV-MIGR-Foxp3逆转录病毒载体及研究体外转染获得的人CD4+CD25+Foxp3+T细胞的免疫抑制功能。扩增人Foxp3编码基因,插入pMSCV-MIGR逆转录病毒载体,构建Foxp3逆转录病毒真核表达载体。磷酸钙沉淀法转染Pheonix E包装细胞。包装病毒再感染PT67细胞,获得永久产毒的PT67细胞。病毒上清感染免疫磁珠分离健康体检者PBMC中CD4+CD25-细胞,诱导CD4+CD25+Foxp3+T细胞,3H-thymidine掺入法测定其对CD4+CD25-细胞增殖的免疫抑制作用。结果显示,带有绿色荧光蛋白的pMSCV-MIGR-Foxp3逆转录病毒可以感染CD4+CD25-T细胞,使其表达Foxp3。CD4+CD25-细胞体外增殖可以被转染诱导的CD4+CD25+Foxp3+T细胞所抑制,提示转染诱导的CD4+CD25+Foxp3+T细胞具有免疫抑制功能,为进一步研究体外诱导CD4+CD25-Foxp3+调节性T细胞功能奠定基础。     

针刺对胚胎着床障碍大鼠CD4+CD25+Foxp3+调节性T细胞的影响

 目的：观察针刺对胚胎着床障碍大鼠CD4+CD25+Foxp3+Treg细胞的影响。方法：144只孕鼠随机分为对照组（N）、米非司酮组（M）、米非司酮+针刺组（A）和米非司酮+黄体酮组（W）,每组随机再分为6 d组、8 d组和10 d组。其中M组、A组和W组妊娠1 d给予米非司酮-麻油溶液造模,N组则给予等量麻油溶液。同时,每天下午A组固定并行针刺三阴交和后三里,N组和M组仅固定,W组肌肉注射黄体酮,直到处死当天结束。统计孕鼠胚胎着床数,用流式细胞术检测外周血CD4+CD25+Foxp3+Treg细胞和子宫内膜的CD4+Foxp3+Treg细胞的比例,Western blotting和real-time PCR测定着床点的子宫内膜Foxp3的表达。结果：与N组相比,M组的着床胚胎数、外周血CD4+CD25+Foxp3+Treg细胞和子宫内膜CD4+Foxp3+Treg细胞的比例、着床点子宫内膜Foxp3蛋白和mRNA的表达均明显下降（P<005）;与M组相比,A组和W组的着床胚胎数、外周血CD4+CD25+Foxp3+Treg细胞和子宫内膜CD4+Foxp3+Treg细胞的比例以及着床点子宫内膜Foxp3蛋白和mRNA的表达均有不同程度地升高。结论: 针刺改善胚胎着床障碍大鼠的胚胎着床可能与CD4+CD25+Foxp3+Treg细胞的调节密切相关。     

Competition controls the rate of transition between the peripheral pools of CD4+CD25- and CD4+CD25+ T cells

Recent reports have hinted that it is possible to regenerate CD4+CD25+ regulatory T cells (Treg) from CD4+CD25- cells, a phenomenon termed conversion. We evaluated the relative contribution of this process to the Treg pool by transferring purified populations of CD4+ T cells into T cell-deficient mice. We report that conversion of CD25- cells into the CD4+CD25+Treg pool is minor if other bona fide CD25+ Tregs are present. Moreover, in the same hosts, the loss of CD25 expression by a population of Tregs also decreases in the presence of co-injected CD4+CD25- cells. Thus, the rate of exchange between CD25- and CD25+ T-cell populations is determined by the presence or absence of T-cell competitors. Our results attest for the role of competition in the contribution of different T-cell subsets for the regeneration of the peripheral CD4+ T-cell pool during lymphopenia.     

CD25+ CD4+ T cells compete with naive CD4+ T cells for IL-2 and exploit it for the induction of IL-10 production

Maintenance of homeostasis in the immune system involves competition for resources between T lymphocytes, which avoids the development of immune pathology seen in lymphopenic mice. CD25+ CD4+ T cells are important for homeostasis, but there is as yet no consensus on their mechanisms of action. Although CD25+ CD4+ T cells cause substantial down-regulation of IL-2 mRNA in responder T cells in an in vitro co-culture system, the presence of IL-protein can be demonstrated by intracellular staining. As a consequence of competition for IL-2, CD25+ CD4+ T cells further up-regulate the IL-2R alpha chain (CD25), a process that is strictly dependent on IL-2, whereas responder T cells fail to up-regulate CD25. Similarly, adoptive transfer into lymphopenic mice showed that CD25+ CD4+ T cells interfere with CD25 up-regulation on co-transferred naive T cells, while increasing their own CD25 levels. IL-2 sequestration by CD25+ CD4+ T cells is not a passive phenomenon but instead initiates--in conjunction with signals through the TCR--their differentiation to IL-10 production. Although IL-10 is not required for in vitro suppression, it is vital for the in vivo function of regulatory T cells. Our data provide a link explaining the apparent difference in regulatory mechanisms in vitro and in vivo.     

支气管哮喘患者外周血Th17、CD4~+CD25~+Treg细胞表达特征

目的:探讨外周血Th17和CD4+CD25+调节性T细胞(Treg)在支气管哮喘患者中的表达特征。方法:41例慢性持续期哮喘患者,分为间歇-轻度组(n=23)和中重度组(n=18),行肺功能检查和哮喘控制问卷(ACQ)调查,20例正常人作为对照。通过流式细胞术检测外周血Th17和CD4+CD25+Treg细胞的比例。ELISA检测血浆以及植物血凝素刺激24小时后外周血单个核细胞(PBMC)上清液中的IL-17、IL-10、TGF-β水平。结果:中重度哮喘组外周血Th17细胞比例及血浆IL-17水平高于间歇-轻度哮喘和正常人组,而外周血CD4+CD25+Foxp3+Treg细胞比例及血浆IL-10、TGF-β水平则降低。中重度哮喘组PBMC上清液中IL-17水平增高。哮喘患者FEV1(%预计值)与Th17细胞及血浆IL-17表达成负相关,与CD4+CD25+Treg表达成正相关。ACQ平均得分与Th17细胞和血浆IL-17表达成正相关,与外周血CD4+CD25+Treg表达成负相关。结论:中重度哮喘中外周血Th17细胞应答增强,而CD4+CD25+Treg细胞缺乏,哮喘的严重程度及症状控制与外周血Th17/Treg免疫应答失衡密切相关。