Inability to mediate prolonged reduction of regulatory T Cells after transfer of autologous CD25-depleted PBMC and interleukin-2 after lymphodepleting chemotherapy

CD25CD4 regulatory T cells (Treg) regulate peripheral self-tolerance and possess the ability to suppress antitumor responses, which may explain the poor clinical response of cancer patients undergoing active immunization protocols, and provides the rationale for neutralizing Treg cells in vivo to strengthen local antitumor immune responses. Because interleukin-2 (IL-2) mediates tumor regression in about 15% of treated patients but simultaneously increases Treg cells, we hypothesized that transient elimination of Treg cells will enhance the clinical effectiveness of IL-2 therapy. In the current study, 5 patients with metastatic melanoma who were refractory to prior IL-2 received a lymphodepleting preparative regimen followed by the adoptive transfer of autologous lymphocytes depleted of CD25 Treg cells and high-dose IL-2 administration. CD25 cells were eliminated from patient leukapheresis samples using a clinical-grade, large-scale immunomagnetic system, leaving CD8 and CD25CD4 T cells intact. In the early aftermath of CD25 Treg cell-depleted cell infusion, CD25FOXP3+ CD4 Treg cells rapidly repopulated the peripheral blood of treated patients with 18% to 63% of CD4 T cells expressing FOXP3. Recovering CD25CD4 T cells exhibited suppressive activity against CD25CD4 effector T-cell proliferation in vitro. No patient experienced objective tumor regression or autoimmunity. Our results indicate that in vivo transfer of autologous CD25-depleted mononuclear populations to lymphopenic patients in combination with high-dose IL-2 is not sufficient to mediate prolonged reduction of Treg cells after IL-2 administration.     

Large-scale depletion of CD25+ regulatory T cells from patient leukapheresis samples

The ability to selectively enrich or deplete T lymphocytes of specific phenotype and function holds significant promise for application in adoptive immunotherapy protocols. Although CD4+ T cells can have an impact on CD8+ T-cell effector function, memory, and maintenance, a subset of CD4+ T cells, CD25+ regulatory T cells (Treg), can regulate peripheral self tolerance and possess the ability to suppress antitumor responses. The authors report the ability to selectively deplete CD25+ Treg cells from patient leukapheresis samples using a clinical-grade, large-scale immunomagnetic system. Using leukapheresis samples containing up to 1.3 x 10(10) white blood cells, efficient depletion of Treg cells was measured by flow cytometric analysis of CD25 expression and FOXP3 expression on post-depletion products. Remnant CD25+ cells could not be detected in CD25-depleted products after short-term culture in IL-2 or enriched following secondary immunomagnetic selection for CD25+ cells, confirming that efficient depletion had occurred. In parallel to efficient enrichment of CD25- cells, immunomagnetic selection resulted in the recovery of Treg cells, since CD25+ lymphocytes removed during depletion were primarily composed of CD4+ T cells that expressed high levels of FOXP3 and possessed suppressive activity against autologous TCR-stimulated CD4+ CD25- T cells in vitro. These results show that selective separation of functional CD25+ Treg cells from large-scale samples can be performed in large scale under clinical-grade conditions with sufficient selection, recovery, viability, ability to expand, and function for potential use in adoptive immunotherapy.     

再生障碍性贫血患者CD4+ CD25+ CD127low调节性T细胞及Notch1表达水平的变化

目的 测定再生障碍性贫血(AA)患者治疗前后外周血CD4+ CD25+ CD127low调节性T细胞(Treg)的数量及叉头翼状螺旋转录因子(FOXP3)mRNA、Notch1 mRNA的表达水平,探讨Treg在AA发病中的作用及其机制.方法 流式细胞术检测29例初发AA患者、14例环孢素(CsA)治疗后恢复期及11例治疗后未恢复期患者外周血中CD4+ CD25+ CD127low T细胞、CD4+ CD25+ T细胞的数量,并与正常对照比较;采用RT-PCR检测FOXP3 mRNA和Notch1 mRNA的表达水平,分析两者相关性.结果AA初发组及治疗后未恢复组患者外周血中活化CD4+ CD25+ T细胞占CD4+ T细胞比例分别为(4.3±0.7)%、(4.2±0.6)%,明显高于正常对照组[(2.4±0.8)%](P＜0.05).CsA治疗后恢复组患者比例下降为(2.6±0.7)%(P＜0.05),与对照组比较差异无统计学意义.AA初发组及未恢复组CD4+ CD25+ CD127low T细胞在CD4+ T细胞中的比例分别为(2.4±1.2)%、(2.5±1.1)%,较正常对照组[(7.1±2.7)%]及恢复组[(5.3±1.0)%]明显降低(P值均＜0.01);但后两组比较差异无统计学意义.AA初发组患者FOXP3 mRNA及Notch1 mRNA分别为(0.260±0.011)和(0.018±0.005),较正常对照[(1.307±0.011)和(0.308±0.028)]表达明显下调(P值均＜0.01),治疗后分别为(1.287±0.012)和(0.281±0.013),表达较初发组显著提高(P值均＜0.01),与对照组比较差异无统计学意义(P值均＞0.05).AA患者CD4+ CD25+ CD127low T细胞、FOXP3均与Notch1表达呈正相关性(P值均＜0.01).结论AA患者外周血CD4+ CD25+ CD127low Treg减少,其抑制作用减弱,导致自身反应性T细胞过度活化,抑制造血.其作用机制之一可能与靶细胞表面Notch1分子表达降低相关.     

人CD4+FOXP3+T细胞的异质性研究进展

CD4+ CD25+调节性T细胞(Treg)是一群具有免疫调节功能的细胞,对维持自身免疫耐受和免疫自稳必不可少,FOXP3特异性表达于Treg细胞,是Treg细胞发育、活化、发挥功能的关键.目前,CD4+ FOXP3+T淋巴细胞常被用来定义Treg细胞进行科学研究,而最近研究表明,人CD4+ FOXP3+T淋巴细胞存在表型和功能上的异质性,这其中包括具有免疫抑制功能的CD4+ FOXP3+ Treg,还包含没有抑制功能的其它类型T细胞,而这些不同功能的细胞亚群可以通过表型的差异加以区分.本文就近年来关于CD4+ FOXP3 +T细胞亚群表型特征和功能的异质性研究作一综述.     

CD4+CD25+调节性T细胞在特发性血小板减少性紫癜患者中的变化

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。     

CD4+CD25+ T regulatory cells, immunotherapy of cancer, and interleukin-2

CD4+CD25+ T regulatory (Treg) cells control immunologic tolerance to self-antigens and play a role in suppressing antitumor immune responses, but the mechanism of suppression in vivo remains uncertain. Recently, signaling through the high-affinity interleukin-2 (IL-2) receptor has been shown to be critical for Treg cell differentiation and survival in vivo. Mice deficient in IL-2 or its receptor (CD25 or CD122) or deficient in downstream signaling molecules, including JAK-3 and STAT-5, do not develop a stable population of Treg cells and subsequently acquire lymphoproliferative disease and autoimmunity. in vitro, IL-2 is required to expand Treg cells and to induce their suppressive characteristics. Conversely, IL-2-based regimens can activate cellular antitumor immunity and are the mainstay of immunotherapies directed against melanoma and kidney cancers. Given the seemingly disparate effects of IL-2, the authors discuss the possibility that IL-2 may not be the optimal T-cell growth factor in vivo, but rather an inducer of self-tolerance. The authors propose that other gamma c-signaling cytokines, including IL-15, may be alternative choices for the immunotherapy of cancer.     

骨髓增生异常综合征患者CD4+CD25+FoxP3+Treg细胞特点及环孢素对其的影响

目的探讨骨髓增生异常综合征(myelodysplastie syndrome,MDS)-难治性贫血(refractory anemia,RA)及难治性血细胞减少伴有多系发育异常(refractory cytopenia with multiple dysplasia,RCMD)患者CD4+CD25+FOXP3+Treg细胞与白细胞介素(interleukin,IL)-10表达水平,评估环孢素对MDS患者CD4+CD25+FOXP3+Treg细胞的影响。方法选择2016年1月至2018年1月于新疆维吾尔自治区人民医院25例MDS-RA及RCMD患者(MDS组)和13名健康对照(健康对照组),采用流式细胞术及酶联免疫吸附试验检测外周血标本CD4+CD25+FOXP3+Treg与IL-10表达水平,检测MDS-RA及RCMD患者在应用以环孢素为基础的免疫抑制方案治疗前、治疗6个月后及MDS组治疗有效及无效的CD4+CD25+FOXP3+Treg与IL-10的表达情况。结果全部25例患者中,13例(52%)有效,12例(48%)无效。MDS组CD4+CD25+FOXP3+Treg占CD4+T细胞比例显著高于健康对照组[(0.37±0.10)%与(0.12±0.06)%,t=2.02,P<0.001]。MDS组IL-10水平显著高于健康对照组[(7.16±1.27)μg/L与(2.75±1.06)μg/L,t=2.03,P<0.001]。MDS治疗有效组CD4+CD25+FOXP3+Treg细胞比例低于无效组[(0.15±0.06)%与(0.26±0.08)%,t=1.71,P<0.001],有效组IL-10水平低于无效组[(3.22±1.01)μg/L与(4.25±1.22)μg/L,t=2.06,P=0.030]。25例MDS患者外周血CD4+CD25+FOXP3+Treg比例与IL-10表达水平呈正相关关系(r=0.35,P=0.02)。结论MDS患者存在CD4+CD25+FOXP3+Treg细胞与IL-10的表达升高,环孢素治疗后降低。     

人CD4~+FOXP3~+T细胞的异质性研究进展

CD4+CD25+调节性T细胞(Treg)是一群具有免疫调节功能的细胞,对维持自身免疫耐受和免疫自稳必不可少,FOXP3特异性表达于Treg细胞,是Treg细胞发育、活化、发挥功能的关键。目前,CD4+FOXP3+T淋巴细胞常被用来定义Treg细胞进行科学研究,而最近研究表明,人CD4+FOXP3+T淋巴细胞存在表型和功能上的异质性,这其中包括具有免疫抑制功能的CD4+FOXP3+Treg,还包含没有抑制功能的其它类型T细胞,而这些不同功能的细胞亚群可以通过表型的差异加以区分。本文就近年来关于CD4+FOXP3+T细胞亚群表型特征和功能的异质性研究作一综述。     

流式细胞术检测RA患者外周血CD4^＋CD25^＋FOXP3^＋ Treg细胞及其GITR表达

目的研究FOXP3和糖皮质激素诱导的肿瘤坏死因子受体(GITR)在类风湿关节炎(RA)患者外周血Treg细胞的表达并探讨其临床意义。方法用五色流式细胞术(FCM)检测40例健康体检者、61例RA患者外周血CD4 CD25 FOXP3 调节性T细胞(Treg)及其中GITR的表达情况。结果RA患者组FOXP3的平均荧光强度(MFI)低于健康对照组(P<0.05),CD4 CD25 FOXP3 Treg占CD4 T细胞的比例、CD4 CD25 FOXP3 Treg中GITR的表达率、GITR MFI和健康对照组相比无统计学差异(P>0.05);活动期RA患者的FOXP3 MFI和GITR MFI均显著低于非活动期组(P<0.01和P=0.032),CD4 CD25 FOXP3 Treg占CD4 T细胞中的比例、CD4 CD25 FOXP3 Treg中GITR的表达率与非活动期组相比无统计学差异(P>0.05)。结论RA患者的FOXP3表达低下,活动期组的FOXP3表达低于非活动期组,为其作为RA病情变化的判断指标提供进一步的证据。     

Defective regulatory and effector T cell functions in patients with FOXP3 mutations

The autoimmune disease immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) is caused by mutations in the forkhead box protein P3 (FOXP3) gene. In the mouse model of FOXP3 deficiency, the lack of CD4+ CD25+ Tregs is responsible for lethal autoimmunity, indicating that FOXP3 is required for the differentiation of this Treg subset. We show that the number and phenotype of CD4+ CD25+ T cells from IPEX patients are comparable to those of normal donors. CD4+ CD25high T cells from IPEX patients who express FOXP3 protein suppressed the in vitro proliferation of effector T cells from normal donors, when activated by "weak" TCR stimuli. In contrast, the suppressive function of CD4+ CD25high T cells from IPEX patients who do not express FOXP3 protein was profoundly impaired. Importantly, CD4+ CD25high T cells from either FOXP3+ or FOXP3- IPEX patients showed altered suppression toward autologous effector T cells. Interestingly, IL-2 and IFN-gamma production by PBMCs from IPEX patients was significantly decreased. These findings indicate that FOXP3 mutations in IPEX patients result in heterogeneous biological abnormalities, leading not necessarily to a lack of differentiation of CD4+ CD25high Tregs but rather to a dysfunction in these cells and in effector T cells.     

CD4+CD25+ T cells regulate virus-specific primary and memory CD8+ T cell responses

Naturally occurring CD4+CD25+ regulatory T cells appear important to prevent activation of autoreactive T cells. This article demonstrates that the magnitude of a CD8+ T cell-mediated immune response to an acute viral infection is also subject to control by CD4+CD25+ T regulatory cells (Treg). Accordingly, if natural Treg were depleted with specific anti-CD25 antibody before infection with HSV, the resultant CD8+ T cell response to the immunodominant peptide SSIEFARL was significantly enhanced. This was shown by several in vitro measures of CD8+ T cell reactivity and by assays that directly determine CD8+ T cell function, such as proliferation and cytotoxicity in vivo. The enhanced responsiveness in CD25-depleted animals was between three- and fourfold with the effect evident both in the acute and memory phases of the immune response. Surprisingly, HSV infection resulted in enhanced Treg function with such cells able to suppress CD8+ T cell responses to both viral and unrelated antigens. Our results are discussed both in term of how viral infection might temporarily diminish immunity to other infectious agents and their application to vaccines. Thus, controlling suppressor effects at the time of vaccination could result in more effective immunity.     

RA患者外周血CD4/CD8 T细胞比值及CD4+ CD25+ T细胞的检测及其临床意义

目的 观察活动期类风湿性关节炎（RA）患者外周血T细胞CD4／CD8比值及CD4^＋ CD25^＋T细胞（Tn细胞）的数量,探讨其在RA诊治中的价值。方法 用流式细胞术检测CD4^＋ CD25^＋T细胞及TR细胞的数量。结果 49例急性期RA患者的CD4／CD8比值和TR细胞数量显著高于正常人群组。28例RA患者治疗后的TR细胞数量显著高于治疗前,而CD4／CD8比值的变化无统计学意义。结论 RA治疗后症状改善患者,TR细胞数量明显上升,RA的发病和发展与该细胞数量密切相关。     

慢性特发性血小板减少性紫癜患者外周血树突细胞的变化及意义

目的 探讨慢性特发性血小板减少性紫癜(ITP)患者体内树突细胞(DC)数量和功能的变化.方法 慢性ITP患者予以大剂量地塞米松(HD-DXM)冲击治疗,剂量40 mg/d,口服,连续4 d,观察短期疗效.用流式细胞术检测患者外周血中髓系DC(mDC)和浆细胞样DC(pDC)在治疗前后绝对数量的变化及与CD4+CD25+调节性T(Treg)细胞的相关性;流式细胞术检测外周血总Dc表面协同刺激分子的表达.将慢性ITP患者外周血单核细胞来源的DC、CD4+T淋巴细胞与自身血小板或健康人同源异基因血小板混合培养,观察CD4+T淋巴细胞增殖情况,检测DC血小板相关抗原的呈递功能.结果 与正常对照组比较,慢性ITP患者外周血pDC和mDC绝对数量均无明显变化(P值均》0.05);而外周血CD4+FOXP3+T细胞数明显降低(P《0.01),pDc和mDC与CD4+FOXP3+T细胞数之间均存在负相关性(r=-0.396,P=0.045和r=-0.410,P=0.037).HD-DXM治疗初始反应率达92.3%,pDC绝对数量较治疗前减少达75.5%(P《0.01);而mDC较治疗前虽增加了24.3%(P《0.05),但mDC上CD11c表达的平均荧光强度(MFI)从治疗前340±30降至199±21(P《0.01);CD4+F0xP3+T细胞数较治疗前显著增加(P《0.01),治疗后pDC与CD4+F0XP3+T细胞存在负相关(r=-0.524,P=0.006),而mDC与CD4+F0XP3+T细胞间无相关性(r=-0.360,P=0.071).慢性ITP患者外周血DC表面协同刺激分子CD86表达的MFI明显高于正常对照组(P《0.05);CD86、CD40、CD80表达阳性率及CD40、CD80表达的MFI与正常对照组比较差异均无统计学意义(P值均》0.05).慢性ITP患者CD4+T淋巴细胞增殖反应强度高于对照组(P《0.05),DC对血小板相关抗原呈递功能亢进.结论 DC可能参与了慢性ITP的免疫发病机制,并与CD4+CD25+Treg细胞有一定的关联.     

骨髓增生异常综合征患者CD4^＋ CD25^＋调节性T细胞、调控基因FOXP3的表达及意义

目的探讨骨髓增生异常综合征（MDS）患者CD4^＋ CD25^＋调节性T细胞（CD4^＋ CD25^＋ Treg细胞）和调控基因FOXP3的表达及意义。方法分离22例MDS患者[MDS组,根据MDS分型标准分为：难治性贫血组（RA组）6例、难治性血细胞减少伴有多系发育异常组（RCMD组）11例、难治性贫血伴原始细胞增多组（RAEB组）5例]和8例正常健康者骨髓单个核细胞,采用免疫荧光标记和流式细胞仪检测CD4^＋ CD25^＋ Treg细胞占CD4^＋ T细胞比例;提取骨髓单个核细胞RNA,采用RT-PCR检测FOXP3基因的表达水平。结果MDS组CD4^＋ CD25^＋ Treg细胞比例、FOXP3基因表达水平与正常对照组比较,差异均无统计学意义（均P〉0.05）;RA组、RAEB组CD4^＋ CD25^＋ Treg细胞比例、FOXP3基因表达水平与正常对照组比较,差异均有统计学意义（均P〈0.01）;RCMD组CD4^＋ CD25^＋ Treg细胞比例、FOXP3基因表达水平与正常对照组比较,差异均无统计学意义（均P〉0.05）;RCMD组、RAEB组CD4^＋ CD25^＋ Treg细胞比例、FOXP3基因表达水平与RA组比较,差异均有统计学意义（均P〈0.01）;RA组、RCMD组CD4^＋ CD25^＋ Treg比例、FOXP3基因表达水平与RAEB组比较,差异均有统计学意义（均P〈0.01）。结论MDS患者CD4^＋ CD25^＋ Treg占CD4^＋ T细胞比例及FOXP3基因表达水平随预后危险级别的升高而升高,提示免疫异常是MDS疾病的发生、发展的一个促进因素。     

CD4+ CD25+ regulatory T cells control T helper cell type 1 responses to foreign antigens induced by mature dendritic cells in vivo

Recent evidence suggests that in addition to their well known stimulatory properties, dendritic cells (DCs) may play a major role in peripheral tolerance. It is still unclear whether a distinct subtype or activation status of DC exists that promotes the differentiation of suppressor rather than effector T cells from naive precursors. In this work, we tested whether the naturally occurring CD4+ CD25+ regulatory T cells (Treg) may control immune responses induced by DCs in vivo. We characterized the immune response induced by adoptive transfer of antigen-pulsed mature DCs into mice depleted or not of CD25+ cells. We found that the development of major histocompatibility complex class I and II-restricted interferon gamma-producing cells was consistently enhanced in the absence of Treg. By contrast, T helper cell (Th)2 priming was down-regulated in the same conditions. This regulation was independent of interleukin 10 production by DCs. Of note, splenic DCs incubated in vitro with Toll-like receptor ligands (lipopolysaccharide or CpG) activated immune responses that remained sensitive to Treg function. Our data further show that mature DCs induced higher cytotoxic activity in CD25-depleted recipients as compared with untreated hosts. We conclude that Treg naturally exert a negative feedback mechanism on Th1-type responses induced by mature DCs in vivo.     

CD4~+CD25~+FOXP3~+调节性T细胞在结核病发生中的作用研究

目的:探讨CD4+CD25+FOXP3+调节性T细胞在结核病发生中的作用。方法:采用回顾性分析的方法,分析我院收治的60例结核病患者(观察组)和60例健康体检者(对照组)的临床资料。结果:观察组治疗前CD4+CD25+FOXP3+调节性T细胞比例明显高于对照组,治疗2、6个月末观察组患者CD4+CD25+FOXP3+调节性T细胞比例明显降低,观察组CD4+CD25+FOXP3+调节性T细胞比例与CD4+T细胞、CD8+T细胞、IFN-γ和IL-4呈现明显的负相关(P<0.05)。结论:针对CD4+CD25+FOXP3+调节性T细胞在结核病发生机制中的作用,开展从免疫治疗和结核病疫苗设计提供新的作用靶点和诊疗依据,值得临床推广应用。     

地塞米松联合IL-2对供鼠体内调节性T细胞选择性扩增作用及对急性移植物抗宿主病反应的抑制作用

目的 通过地塞米松(Dex)联合IL-2处理小鼠,建立体内扩增调节性T细胞(Treg细胞)的方法 .观察用该方法 处理的小鼠脾细胞移植后受鼠急性移植物抗宿主病(aGVHD)的发生与转归.方法 使用Dex和IL-2处理雄性C57BL/6N供鼠3 d后提取脾单个核细胞(MNC),用流式细胞术(FCM)分析CD4~+ CD25~+、CD25~+ FOXP3~+细胞的变化.,以以上方法 处理的雄性C57BL/6N小鼠为供者,对雌性BALB/c受鼠进行非清髓异基因淋巴细胞移植.移植后观测受鼠的生存率、生存时间、组织病理学变化,以及用PCR和FCM分析测定受鼠嵌合体等来评价aGVHD的发生.结果 经过Dex和IL-2联合处理,供鼠脾CD4~+ CD25~+ FOXP3~+ Treg细胞数量[(24.2±7.6)%]明显高于对照组[(4.0±0.8)%](P=0.01).Dex联合IL-2组供鼠Treg细胞与效应T细胞(Teff)的比值(0.43±0.15)显著高于对照组(0.14±0.01)(P=0.01).经过Dex联合IL-2处理供鼠后进行异基因淋巴细胞移植,受鼠aGVHD明显减轻,中位生存时间＞60 d,与对照组的中位生存时间12 d相比明显延长(P=0.0045).对照组出现典型的aGVHD表现,移植后2周Dex联合IL-2组和对照组的总体死亡率分别为29.4%和71.4%(P＜0.05).结论 经IL-2和糖皮质激素处理供鼠后进行主要组织相容性抗原复合物完全不相合脾淋巴细胞移植能明显减轻aGVHD,显著延长生存时间,可能与供者体内诱导扩增的Treg细胞增加有关.     

急性冠脉综合征患者外周血CD4+CD25+调节性T细胞的变化及其临床意义

目的 探讨急性冠脉综合征（acute coronary syndrome,ACS）患者的外周血CD4^＋CD25^＋调节性T细胞（CD4^＋CD25^＋Treg）和CD4^＋CD25^＋曲T细胞（CD4^＋CD25^＋^high Treg）的水平及其临床意义。方法 采用流式细胞术检测15例急性心肌梗死患者、20例不稳定性心绞痛、11例稳定性心绞痛和16例健康体检者（对照组）的外周血CD4^＋CD25^＋Treg和CD4^＋CD25^＋^high Treg的水平。结果 ACS患者CD4^＋CD25^＋Treg占CD4^＋T细胞的比例较稳定性心绞jjl;和对照组显著减少,CD4^＋CD25^＋high Treg占CD4^＋T细胞比例的差异无显著性。结论 ACS患者外周血具有免疫负调节作用的CD4^＋CD25^＋Treg水平减低,可能促进了动脉粥样硬化的进展。     

CD4+CD25+ regulatory T cells suppress allograft rejection mediated by memory CD8+ T cells via a CD30-dependent mechanism

CD4(+)CD25(+) regulatory T (Treg) cells suppress naive T cell responses, prevent autoimmunity, and delay allograft rejection. It is not known, however, whether Treg cells suppress allograft rejection mediated by memory T cells, as the latter mount faster and stronger immune responses than their naive counterparts. Here we show that antigen-induced, but not naive, Treg cells suppress allograft rejection mediated by memory CD8(+) T cells. Suppression was allospecific, as Treg cells induced by third-party antigens did not delay allograft rejection. In vivo and in vitro analyses revealed that the apoptosis of allospecific memory CD8(+) T cells is significantly increased in the presence of antigen-induced Treg cells, while their proliferation remains unaffected. Importantly, neither suppression of allograft rejection nor enhanced apoptosis of memory CD8(+) T cells was observed when Treg cells lacked CD30 or when CD30 ligand-CD30 interaction was blocked with anti-CD30 ligand Ab. This study therefore provides direct evidence that pathogenic memory T cells are amenable to suppression in an antigen-specific manner and identifies CD30 as a molecule that is critical for the regulation of memory T cell responses.