CD4~+CD25~+Foxp3~+调节性T细胞在HDCP外周血中水平变化及其意义

目的:探讨妊娠期高血压疾病患者(HDCP)外周血中CD4+CD25+Foxp3+调节性T细胞水平变化及其意义。方法:选取2013年1月至2014年8月在我院治疗的妊娠期高血压疾病(HDCP)患者46例,其中轻度子痫前期22例,重度子痫前期24例,同时选取同期正常孕妇25例,采用流式细胞术检测各组患者外周血CD4+CD25+Foxp3+调节性T细胞。结果:重度子痫前期组CD4+CD25+T细胞比例为(5.01±1.04)%,低于轻度子痫前期组的(7.38±1.26)%和正常孕妇组的(12.59±2.48)%,差异有统计学意义(P0.05);轻度子痫前期组和重度子痫前期组CD4+CD25+Foxp3+T细胞绝对数分别为(0.96±0.11)×107和(0.63±0.12)×107,CD4+CD25+Foxp3+Treg/CD4+T分别为(2.58±0.93)%和(1.84±0.85)%,均低于正常孕妇组的(1.85±0.17)×107和(5.11±0.99)%,差异有统计学意义(P0.05);轻度子痫前期组和重度子痫前期组血清雌三醇分别为(6.16±2.17)mg/L和(3.27±1.15)mg/L,明显低于正常孕妇组的(11.34±2.4)mg/L,差异有统计学意义(P0.05)。结论:妊娠高血压疾病患者CD4+CD25+Foxp3+调节性T细胞明显减少,同时血清雌三醇也有所降低,这些可能与妊娠期高血压疾病的发病机制以及免疫耐受有关。     

CD39分子在子痫前期患者外周血CD4+T细胞及脐静脉内皮细胞的表达及临床意义北大核心CSCD

目的：探讨CD39分子在子痫前期患者外周血CD4+T细胞、Treg、Foxp3-CD4+T细胞及脐静脉内皮细胞的表达及临床意义。方法：采集59例正常妊娠者、23例妊娠期高血压患者及65例子痫前患者(包括28例轻度子痫前期患者和37例重度子痫前期患者)外周血，流式细胞技术检测各组妊娠妇女外周血CD4+T细胞、Treg(Foxp3+CD4+T细胞)、Foxp3-CD4+T细胞比例及CD39分子表达率。随机获取胎儿分娩后的脐带(正常妊娠组18例、重度子痫前期组20例)，检测脐静脉血管内壁细胞CD31+CD39+内皮细胞群比例。结果：正常妊娠组、妊娠期高血压组、子痫前期组3组母体外周血CD4+T细胞比例[(33.71±9.80)%vs (29.59±14.22)%vs (29.63±11.11)%]及CD39表达率[2.84(0.89～5.51) vs 2.50(0.89～4.19) vs 1.39(0.79～3.51)]差异无统计学意义(P>0.05)。正常妊娠组Treg比例及CD39表达率明显高于子痫前期组[3.25(1.39～4.53) vs 1.63(1.01～2.58);33.90(22.80～59.40) vs 21.20(16.70～32.55),P<0.001]；正常妊娠组Foxp3-CD4+T细胞比例明显低于子痫前期组[94.40(93.00～96.10) vs 95.60(94.10～97.40),P=0.016]，但3组CD39表达率差异无统计学意义[1.80(0.55～4.49) vs 1.92(0.54～3.60) vs 0.92(0.49～3.24),P=0.340]。轻度子痫前期组与重度子痫前期组外周血CD4+T细胞[(32.35±10.51)%vs (27.56±11.24)%]、Treg[1.80(0.93～2.58) vs 1.44(1.03～2.58)]、Foxp3-CD4+T细胞[95.6(94.5～97.1) vs 95.6(94.0～97.6]比例差异无统计学意义(P>0.05)；轻度子痫前期组CD4+T细胞、Treg、Foxp3-CD4+T细胞CD39表达率均明显高于重度子痫前期组[2.08(1.20～5.05) vs 0.95(0.68～1.78);26.20(19.55～58.55) vs 17.60(13.90～23.15);2.14(0.78～3.69) vs 0.62(0.40～1.73),P<0.05]。重度子痫前期患者脐静脉血管内壁细胞CD31+CD39+内皮细胞群比例明显低于正常妊娠组[6.32(3.27～10.55) vs 18.95(9.90～27.48),P=0.020]。结论：母体外周血发挥免疫抑制功能的Treg数量及CD39分子表达减少可能参与子痫前期发生发展；重度子痫前期患者脐静脉血管内壁细胞CD31+CD39+内皮细胞群较正常妊娠者明显减少，可能与血管内皮损伤机制有关。     

CD4+CD25+Foxp3+调节性T细胞在子痫前期患者外周血与蜕膜中水平变化研究

目的本文检测CD4+CD25+Foxp3+调节性T细胞在子痫前期患者外周血及胎盘附着处蜕膜中的表达,探讨其在子痫前期免疫耐受失衡中的作用。方法选择子痫前期患者20例,正常晚期妊娠患者20例。采用流式细胞仪检测外周血CD4+CD25+Foxp3+的表达;免疫组织化学法检测蜕膜CD4+CD25+调节性T细胞的特异性转录因子Foxp3的表达。结果 1.子痫前期组外周血CD4+CD25+Foxp3+T细胞表达率(1.70±0.23%)明显低于正常晚期妊娠对照组(3.55±0.47%)(P<0.05)。2.蜕膜中Foxp3在子痫前期组的表达阳性率为(16.67%)明显低于正常对照组(66.67%)(P<0.05)。结论子痫前期患者外周血和蜕膜组织中的CD4+CD25+Foxp3+调节性T细胞均低于正常孕妇,提示其数量的减少使其免疫抑制功能减弱,母胎免疫耐受失衡,导致子痫前期的发生。     

CD4+CD25+Foxp3+T细胞在子痫前期中作用机制的研究

目的 探讨子痫前期(PE)患者外周血中CD4+CD25+Foxp3+T细胞及胎盘组织Foxp3的表达水平.方法 73例PE患者分为MPE组(轻度PE,38例)和SPE组(重度PE,35例),以正常的孕妇作为对照组;采用流式细胞术(FCM)检测外周血中CD4+CD25+Foxp3+T细胞的表达水平,采用免疫组化法(IHC)检测胎盘组织Foxp3的表达水平;将Foxp3与CD4+CD25+Foxp3+T、胎盘重量和阿氏(Apgar)评分进行Spearman相关性分析.结果 SPE组、MPE组外周血中CD4+CD25+Foxp3+T细胞表达水平分别为4.23±0.74％、6.58±0.8％,均低于对照组的7.01±0.95 ％(P＜0.05),SPE组外周血中CD4+CD25+Foxp3+T细胞表达水平低于MPE组(P ＜0.05);SPE组、MPE组胎盘组织中Foxp3的阳性表达率分别为28.57％、47.37％,均低于对照组的82.76％(P ＜0.05),SPE组胎盘组织中Foxp3的阳性表达率显著低于MPE组(P＜0.05);胎盘组织中Foxp3的阳性表达率与CD4+CD25+Foxp3+T细胞表达水平、胎盘重量及Apgar评分均呈正相关(P＜0.01).结论 PE与外周血中CD4+CD25+Foxp3+T细胞表达水平下降密切相关.     

结核病患者外周血中CD4~+ CD25~+调节性T细胞水平的检测

探讨CD4~+CD25~+调节性T细胞及其转录因子Foxp3在结核病发病机制中的作用。研究对象为肺结核患者22例(病例组)以及健康对照者23例(对照组)。采用FACS检测外周血CD4~+CD25~+调节性T细胞的百分率,采用real-time PCR检测外周血单个核细胞Foxp3mRNA的表达以及CD4~+CD25~+调节性T细胞与CD4~+T细胞、CD8~+T细胞、IFN-γ和IL-4的相关性。结核病患者外周血CD4~+CD25~+调节性T细胞占CD4~+T细胞的百分率,病例组(3.38±1.23)%高于对照组(1.97±0.62)%,两组比较差异有统计学意义(P0.05)。血清单个核细胞Foxp3 mRNA相对表达水平为134.54±6.76,高于对照组(40.98±2.34,P0.05)。CD4~+CD25~+调节性T细胞与CD4~+T细胞、CD8~+T细胞以及与IFN-γ和IL-4的表达呈负相关。结核病CD4~+CD25~+调节性T细胞数量增加、特异性转录因子Foxp3 mRNA表达上升,由此引发的免疫抑制效应可能是结核病发生发展的重要原因之一。     

外周血CD4~+CD25~+Foxp3~+调节性T细胞影响先兆流产的妊娠预后

分析先兆流产患者妊娠结局与外周血CD4~+CD25~+Foxp3~+调节性T细胞的联系。对先兆流产患者采用黄体酮针40mg im qd,HCG针2000 u im qod,地屈孕酮片1片Bid po,维生素E丸1粒Tid po的治疗方案保胎;采用细胞内染色流式细胞术,分析外周血CD4~+CD25~+Foxp3~+T细胞亚群。结果:28例先兆流产患者经用以上治疗方案保胎后,18例成功,10例失败。经治疗后,保胎成功组外周CD4~+CD25~+Foxp3~+/CD4~+、CD4~+Foxp3~+、CD25~+Foxp3~+T细胞比例显著高于保胎失败组(P0.05),并显著高于保胎治疗前(P0.05)。外周调节性T细胞升调节有利于成功妊娠。     

Neuropilin-1在CD4+ CD25+ T细胞上的表达

目的 探讨neuropilin-1(NRPl)在外周血中CIM+ CD25+ T细胞上的表达以及意义.方法 收集肾移植术后长期存活、慢性移植物肾病和急性排斥患者以及健康成年人的外周血,分离外周血淋巴细胞,用流式细胞仪检测外周血淋巴细胞中CD4+ CD25+ T细胞上NRPl和Foxp3的阳性细胞的百分比.结果 各组CD4+ CD25+ T细胞NRPl的表达率差异有统计学意义(P＜0.05);各组CD4+ CD25+ T细胞Foxp3的表达率差异亦有统计学意义(P＜0.05).长期存活组CD4+ CD25+ T细胞上NRP1和Foxp3表达率分别为19.6%±3.84%、50.19 ±3.90%,显著高于对照及慢性移植物肾病和急性排斥组(P＜0.05);急性排斥组的CD4+ CD25+ T细胞NRP1和Foxp3表达率最低4.64%±1.26%、17.24%±5.29%.各组CD4+ CD25+ T细胞NRP1表达变化趋势与Foxp3变化趋势相同.结论 NRP1在长期存活组的外周血淋巴细胞中CD4+ CD25+ T细胞的表达上调,在急性排斥组时表达下调,且其在各组的表达变化趋势与Foxp3的表达变化趋势是一致的,这就提示CD4+ CD25+ NRP1+ 细胞是一群调节性T细胞,即NRP1是CD4+ CD25+ Treg的一个重要的表面标志.     

子宫内膜异位症患者外周血CD4~+CD25~+Foxp3~+调节性T细胞的变化

观察子宫内膜异位症患者外周血单个核细胞CD4~+CD25~+Foxp3~+调节性T细胞的数量变化,初步探讨其意义。采用流式细胞术检测20例健康对照者(对照组)及46例子宫内膜异位症患者(疾病组临床r-AFS分期:Ⅰ～Ⅱ期26例,Ⅲ～Ⅳ期20例)外周血单个核细胞(PBMC)中CD4~+CD25~+Foxp3~+调节性T细胞数目,并计算CD4~+CD25~+Foxp3~+调节性T细胞占CD4~+T淋巴细胞的百分率;分析不同分期子宫内膜异位症患者外周血CD4~+CD25~+Foxp3~+调节性T细胞的变化。结果显示,与健康对照组相比,疾病组PBMC中CD4~+CD25~+Foxp3~+Treg占CD4~+T淋巴细胞的百分率及CD4~+CD25~+Foxp3~+Treg绝对数均明显升高(P<0.01,P<0.05);疾病组中,Ⅲ～Ⅳ期的PBMC中CD4~+CD25~+Foxp3~+Treg占CD4~+T淋巴细胞的百分比及CD4~+CD25~+Foxp3~+Treg绝对值较Ⅰ～Ⅱ期均明显升高(P<0.01,P<0.05)。提示子宫内膜异位症患者外周血CD4~+CD25~+Foxp3~+调节性T细胞数目和比例增多,可能存在自身免疫调节功能的紊乱,且与病程发展紧密相关。     

新生儿缺氧缺血性脑病患儿外周血CD4+CD25+调节性T细胞的变化及其意义

目的探讨CD4+CD25+调节性T细胞在新生儿缺氧缺血性脑病(HIE)患儿外周血的改变,及其在HIE疾病进程中的意义。方法用流式细胞术分析HIE组患儿92例和对照组31名外周血CD4+CD25+T细胞的变化,及其细胞内foxp3的表达变化。结果轻度、中度和重度HIE组患儿外周血CD4+CD25+T细胞比例分别为(9.26±1.18)%、(6.51±1.35)%和(5.36±1.54)%,对照组为(8.42±2.02)%。轻度HIE组患儿外周血CD4+CD25+T细胞较对照组有增高趋势,但差异无统计学意义(P>0.05);中度和重度HIE组患儿CD4+CD25+T细胞明显低于对照组,差异有统计学意义(P<0.05)。轻度、中度和重度HIE组患儿外周血CD4+CD25+foxp3+T细胞分别为(1.36±1.14)%、(1.21±0.94)%和(1.09±0.54)%,对照组为(1.30±1.17)%。轻度HIE组患儿CD4+CD25+foxp3+T细胞较对照组有增高趋势,但差异无统计学意义(P>0.05)。中度和重度HIE组患儿CD4+CD25+foxp3+T细胞明显低于对照组,差异有统计学意义(P<0.05)。结论中度和重度HIE组患儿CD4+CD25+foxp3+T细胞明显减少,这些调节性T细胞可能参与HIE的病理进程。     

CD4~+CD25~(high) Foxp3~+调节性T细胞在新生儿脐血及成人外周血的比较

目的:检测新生儿脐血及成人外周血中CD4+CD25~(high) Foxp3+调节性T细胞(Treg)的比例,探讨Treg在新生儿脐血中的临床意义.方法:采用流式细胞术(FCM)检测30例新生儿脐血单个核细胞中CD4+T细胞、CD4+CD25+/CD4~+、CD4~+CD25~(high) /CD4~+T细胞百分比以及绝对计数,进一步分析CD4~+CD25~+及CD4~+CD25~(high) T细胞中Foxp3~+的百分比,以及利用RT-PCR方法检测Foxp3 mRNA表达水平,并与27例成人外周血单个核细胞(PBMC)中的上述指标进行比较.结果:与成人PBMC比较,新生儿脐血单个核细胞中CD4~+T细胞百分比及绝对计数均增高(P＜0.01＝;CD4~+CD25~+/CD4~+及CD4~+CD25~(high) /CD4~+百分比减低(P＜0.05＝,但绝对计数增高(P＜0.01＝;新生儿脐血CD4~+CD25~+ 及CD4~+CD25~(high) T细胞中Foxp3~+表达较成人外周血减低(P＜0.01＝;新生儿脐血Foxp3 mRNA表达水平亦较成人外周血减低(P＜0.05＝.结论:新生儿脐血中存在单纯且数量较多的CD4~+CD25~(high) 调节性T细胞,但Foxp3的表达水平低于成人外周血,它们可能具有独特的免疫调节作用,但功能尚未成熟.     

Lower proportion of CD19+IL-10+ and CD19+CD24+CD27+ but not CD1d+CD5+CD19+CD24+CD27+ IL-10+ B cells in children with autoimmune thyroid diseases

Abstract

Introduction: As it is generally known, regulatory B cells (Bregs) control inflammation and autoimmunity. The significance of Bregs in the population of children with autoimmune thyroid diseases (AITD) still offers plenty of potential to explore. The aim of this study was to estimate the expression of Bregs (phenotype CD19⁺CD24⁺CD27⁺IL-10⁺, CD19⁺IL-10⁺, CD1d⁺CD5⁺CD19⁺IL-10⁺ and CD1d⁺CD5⁺CD19⁺CD24⁺CD27⁺) in a paediatric cohort with AITD and in health controls.

Materials and methods: A total of 100 blood samples were obtained from 53 paediatric patients with Graves’ disease (GD) (N?=?12 newly diagnosed, mean age 12.5?±?3.5 and N?=?17 during methimazole therapy, mean age 12.7?±?4.4), Hashimoto’s thyroiditis (HT) (N?=?10 newly diagnosed, mean age 13.3?±?2.9 and N?=?10 during L-thyroxine therapy, mean age 13.7?±?3.4) and compared with healthy controls (C) (N?=?15, mean age 13.1?±?3.1). The expressions of the immune cell populations were analysed by four-color flow cytometry using a FASC Canto II cytometer (BD Biosciences).

Results: There was a decreasing tendency in the number of lymphocytes B producing IL-10 (B10) cells among all B lymphocytes and more widely, also among all lymphocytes, in each study group, as compared to C. We reported a reduction in IL-10 production in Bregs with the expression of CD19⁺CD24⁺CD27⁺IL-10 and CD1d⁺CD5⁺CD19⁺IL-10⁺ in both untreated and treated AITD.

Conclusions: Our data demonstrate that the reduction in the number of Bregs with CD19⁺CD24⁺CD27⁺IL-10⁺ and CD19⁺IL-10⁺ expression could be responsible for breaking immune tolerance and for AITD development in children.     

Circulating CD3+ CD4+ CD+ T lymphocytes in multiple sclerosis

Triple-antibody flow cytometry was used to search for distinctive populations of peripheral blood lymphocyte immunophenotypes in multiple sclerosis (MS). Using monoclonal antibodies to the cell surface markers CD3, CD4, and CD8, T cell subsets were quantified on a cohort of 31 MS patients (not treated with corticosteroids for at least 6 months), 30 healthy donors, and 14 patients with other autoimmune diseases (also corticosteroid treatment-free for at least 6 months). Untreated MS patients displayed a significantly greater population of CD3+CD4+CD8+ circulating T cells than healthy donors (P = 0.023). Patients with other autoimmune diseases displayed mean populations of CD3+CD4+CD8+ cells greater than normal donors and less than MS, but not significantly different from either. An additional 45 MS patients who had received corticosteroid therapy within the previous 6 months were phenotyped. Treatment of symptomatic MS with corticosteroids was associated with a smaller population of circulating CD3+CD4+CD8+ cells. Some MS patients have significantly greater numbers of peripheral blood T lymphocytes simultaneously expressing CD3, CD4, and CD8 surface markers than healthy donors and this population of cells may be reduced by corticosteroids treatment. This triple positive phenotype may be a manifestation of a systemic immune abnormality in MS.     

Prognostic Values of CD38+CD101+PD1+CD8+ T Cells in Pancreatic Cancer

Programmed death-1 (PD-1), a key immune checkpoint molecule, has been developed as an oncotherapy target for various carcinomas. However, treatment with anti-PD-1 elicited only a minimal effect in pancreatic ductal adenocarcinoma (PDAC). Subsequent studies revealed the existence of a subset of PD-1⁺ T cells coexpressing CD38 and CD101, representing a fixed dysfunctional subpopulation that are not able to be rescued by anti-PD-1 immunotherapy. However, whether this subpopulation of PD-1 expressing CD8⁺ T cells could be useful in predicting PDAC stage or prognosing survival is unknown. In this study, we used flow cytometry and immunofluorescence assay to analyze the expression of CD38 and CD101 in 183 clinical PDAC samples, including 84 of peripheral blood and 99 of surgical tissues. High coexpression of CD38/CD101 on peripheral PD-1⁺CD8⁺ T cells or tumor-infiltrating lymphocytes (TILs) was found to be most significantly correlated with Tumor/Node/Metastasis (T/N/M) classification and clinical stage, in contrast PD-1⁺CD8⁺ T cells could not correlate with T classification. CD38/CD101 co-repression on TILs also correlated with the poor survival in these PDAC patient samples. Our data suggest that CD38/CD101 might represent a more helpful biomarker than PD-1 alone for diagnosis and prognosis of PDAC.     

Expansion and differentiation of CD14+CD16(-) and CD14+ +CD16+ human monocyte subsets from cord blood CD34+ hematopoietic progenitors

To determine whether monocytes can be generated from CD34+ hematopoietic progenitors in large numbers, cord blood CD34+ cells were first expanded for 3-10 days in X-VIVO 10 medium supplemented with FCS, stem cell factor (SCF), thrombopoietin (TPO), and Flt-3 Ligand (Flt-3L), and then differentiated in IMDM medium supplemented with FCS, SCF, Flt-3L, IL-3 and M-CSF for 7-14 days. These two step cultures resulted in up to a 600-fold mean increase of total CD14+ cells. Using this approach, two subpopulations of monocytes were obtained: CD14+CD16(-) and CD14++CD16+ occurring at 2:1 ratio. 1.25(OH)2 Vitamin D3 added to the differentiation medium altered this ratio by decreasing proportion of CD14++CD16+ monocytes. In comparison to CD14+CD16(-), the CD14++CD16+ cells showed different morphology and an enhanced expression of CD11b, CD33, CD40, CD64, CD86, CD163, HLA-DR, and CCR5. Both subpopulations secreted TNF and IL-12p40 but little or no IL-10. CD14++CD16+ monocytes released significantly more IL-12p40, were better stimulators of MLR but showed less S. aureus phagocytosis. These subpopulations are clearly different from those present in the blood and may be novel monocyte subsets that represent different stages in monocyte differentiation with distinct biological function.     

Ontogeny of Tumor-associated CD4+CD25+Foxp3+ T-regulatory Cells

ABSTRACT

The critical contribution of CD4+CD25+Foxp3+ T-regulatory cells (Treg) to immune suppression in the tumor microenvironment is well-established. Whereas the mechanisms that drive the generation and accumulation of Treg in tumors have been an active area of study, the information on their origin and population dynamics remains limited. In this review, we discuss the ontogeny of tumor-associated Treg in light of the recently identified lineage markers.     

Imbalance of CD4+CD45R+ and CD4+CD29+ T helper cell subsets in patients with atopic diseases.

To evaluate the proportion of helper cell subsets we studied 18 children with atopic dermatitis, 30 patients with asthma, 27 healthy age-matched controls aged 1 to 17 years and 11 atopic controls without symptoms related to atopy, aged 9-22 years. Lymphocytes were isolated from heparinized peripheral blood and the proportion of CD4+CD29+ and CD4+CD45R+ cells was determined by double-labelling immunofluorescence. Children with atopic dermatitis yielded a significantly (P less than 0.01) higher proportion of CD4+CD45R+ (median 75%) cells compared with normal controls (median 66.6%), whereas the proportion of CD4+CD29+ cells was significantly (P less than 0.01) lower in patients with atopic dermatitis (median 20.4 versus 29.6%). Interestingly, the percentage of CD4+CD45R+ cells shows an age-dependent decline (r = -0.67, P less than 0.01) in the control group, which is not found in the patient group.     

Phenotypic and functional characteristics of CD4+ CD39+ FOXP3+ and CD4+ CD39+ FOXP3neg T-cell subsets in cancer patients

Human CD4(+) CD39(+) regulatory T (Treg) cells hydrolyze exogenous adenosine triphosphate (ATP) and participate in immunosuppressive adenosine production. They contain two T-cell subsets whose role in mediating suppression is not understood. Frequencies of both CD4(+) CD39(+) subsets were evaluated in peripheral blood lymphocytes of 57 cancer patients and in tumor infiltrating lymphocytes (TILs) of 6 patients. CD4(+) CD39(+) and CD4(+) CD39(neg) T cells isolated using immunobeads and cell sorting were cultured under various conditions. Their conversion into CD39(+) FOXP3(+) CD25(+) or CD39(+) FOX(neg) CD25(neg) cells was monitored by multiparameter flow cytometry. Hydrolysis of exogenous ATP was measured in luminescence assays. Two CD4(+) CD39(+) cell subsets differing in expression of CD25, FOXP3, CTLA-4, CD121a, PD-1, latency associated peptide (LAP), glycoprotein A repetitions predominant (GARP), and the cytokine profile accumulated with equal frequencies in the blood and tumor tissues of cancer patients. The frequency of both subsets was significantly increased in cancer. CD39 expression levels correlated with the subsets' ability to hydrolyze ATP. Conventional CD4(+) CD39(neg) T cells incubated with IL-2 + TGF-β expanded to generate CD4(+) CD39(+) FOXP3(+) Treg cells, while CD4(+) CD39(+) FOXP3(neg) CD25(neg) subset cells stimulated via the TCR and IL-2 converted to FOXP3(+) CTLA4(+) CD25(+) TGF-β-expressing Treg cells. Among CD4(+) CD39(+) Treg cells, the CD4(+) CD39(+) FOXP3(neg) CD25(neg) subset serves as a reservoir of cells able to convert to Treg cells upon activation by environmental signals.     

Circulating CD4+CD25+ and CD4+CD25+ T cells in myasthenia gravis and in relation to thymectomy

Studies in experimental animal models of human autoimmune diseases have revealed that CD4⁺CD25⁺ T regulatory (Tr) cells are of thymic origin and have potentials in preventing auto‐aggressive immunity. Myasthenia gravis (MG) is the best‐characterized autoimmune disease. Changes in the thymus are found in a majority of patients with MG. Thymectomy has beneficial effects on the disease severity and course in a substantial proportion of MG patients. But the occurrence and characteristics of Tr cells have not yet been defined in MG. We determined the frequencies and properties of circulating CD4⁺CD25⁺ versus CD4⁺CD25^– cells in MG patients and healthy controls (HCs), with special focus on the effect of thymectomy on CD4⁺CD25⁺ cells. CD4⁺CD25^high cells comprise only about 2% of blood lymphocytes in both MG patients and HCs. Frequencies of CD4⁺CD25^high cells were similar in MG patients irrespective of treatment with thymectomy. CD4⁺CD25⁺ cells in both MG patients and HCs are mainly memory T cells and are activated to a greater extent than CD4⁺CD25^– cells, as reflected by high levels of CD45RO and human leucocyte antigen (HLA)‐DR‐positive cells. In both MG patients and HCs, CD4⁺CD25⁺ cells also contained a high proportion of CD95‐expressing cells as possible evidence of apoptosis‐proneness. Upon stimulation with anti‐CD3/CD28 monoclonal antibodies, CD4⁺CD25⁺ cells responded more vigorously than CD4⁺CD25^– cells in MG, irrespective of treatment with thymectomy, as well as in HCs. Although CD4⁺CD25^– cells are mainly naïve T cells, in non‐thymectomized MG patients, they are activated to a greater extent as reflected by higher expression of HLA‐DR and CD95 on the surface compared to HCs. The data thus show that there is no deficiency of CD4⁺CD25⁺ cells in MG, nor is the proportion of CD4⁺CD25⁺ cells influenced by thymectomy.