程氏蠲痹汤加减方降低佐剂性关节炎大鼠外周血T细胞cAMP水平和CD4~+/CD8~+T细胞比值

目的探讨程氏蠲痹汤加减方(CJBD)对佐剂性关节炎(AA)大鼠T淋巴细胞中的环腺苷酸(c AMP)水平和CD4~+/CD8~+T细胞比值的影响。方法将成年雄性SD大鼠分为正常对照组、AA组、CJBD组和雷公藤多苷片(TGT)组。用吹风冷水和Freund完全佐剂制备大鼠风寒湿痹AA模型,对照组给予生理盐水灌胃,其他组分别给予对应药品,持续7 d。各组大鼠经眼眶取血,分离外周血单个核细胞(PBMC),利用免疫磁珠分选技术分选T淋巴细胞,应用c AMP检测试剂盒检测各组T淋巴细胞的c AMP水平,用流式细胞术检测各组大鼠外周血T细胞中的CD4~+和CD8~+T细胞数,计算CD4~+/CD8~+T细胞比值。结果与正常对照组比较,CJBD组大鼠T淋巴细胞的c AMP表达水平显著降低,TGT组的c AMP含量与正常对照组无显著性差异;CJBD组的CD4~+/CD8~+T细胞比值显著降低。结论 CJBD可降低AA大鼠T淋巴细胞c AMP的水平和CD4~+/CD8~+T细胞比值。     

CHOP方案治疗前后外周T细胞淋巴瘤患者外周血CD45RA~+ T和CD45RO~+ T的变化特点

目的:探讨CHOP方案对外周T细胞淋巴瘤(PTCL)患者外周血中初始和记忆T细胞水平的变化及其临床意义。方法:采用流式细胞术检测20例PTCL患者CHOP方案化疗前后外周血中CD4+CD45RA+、CD4+CD45RO+、CD8+CD45RA+和CD8+CD45RO+T细胞的比例,分析疗效与T细胞亚群的关系。结果:PTCL患者化疗前外周血中CD4+T细胞、CD4+CD45RO+细胞的比例明显降低,CD4+CD45RA+、CD8+、CD8+CD45RO+和CD8+CD45RA+T细胞的比例均明显升高(P<0.05),而化疗后PTCL患者CD4+、CD4+CD45RO+细胞的比例较治疗前升高,CD4+CD45RA+、CD8+、CD8+CD45RO+和CD8+CD45RA+T细胞比例则较治疗前稍下降(P<0.05)。治疗前后化疗有效组的CD4+CD45RA+均明显高于化疗无效组(P<0.05)。结论:CHOP治疗对PTCL患者胸腺输出功能有一定的影响,伴有较高胸腺输出功能者对化疗效果更好。     

泼尼松对大鼠实验性变态反应性脑脊髓炎的影响

目的研究泼尼松(Predn isone,PRD)对大鼠实验性变态反应性脑脊髓炎(EAE)的治疗作用和作用机制。方法豚鼠脊髓匀浆和完全福氏佐剂制成的混合液诱导Lew is大鼠建立EAE模型,10 d后将PRD 5 mg/kg灌胃给予EAE大鼠,连续给药16 d,观察其发病情况、外周血T淋巴细胞CD3 、CD4 、CD8 、NK细胞比率以及脑、脊髓组织病理变化。结果模型组CD3 T淋巴细胞比率63.2%,CD4 T淋巴细胞比率46.8%,CD8 T淋巴细胞比率17.4%,NK细胞比率10.2%;泼尼松组CD3 T淋巴细胞比率69.5%,CD4 T淋巴细胞比率51.8%,CD8 T淋巴细胞比率18.1%,NK细胞比率5.3%。PRD可显著改善恢复期EAE的临床评分,降低外周血NK细胞比率,升高外周血T淋巴细胞CD3 、CD4 比率,抑制大鼠大脑的炎症反应和脱髓鞘改变,但对外周血T淋巴细胞CD8 、CD4 /CD8 比率等无明显影响。结论PRD对EAE大鼠具有治疗作用,其作用机制可能与降低外周血NK细胞比率、升高T淋巴细胞CD3 和CD4 比率有关。     

CD4~+CD25~+调节性T细胞移植对自身免疫性脑脊髓膜炎大鼠的保护作用

目的观察输注CD4~+CD25~+调节性T细胞对实验性自身免疫性脑脊髓膜炎(EAE)模型大鼠后脑和脊髓组织的保护作用及相关机制。方法取SD大鼠30只,随机均分为空白对照组、模型组(实验性自身免疫性脑脊髓炎模型)和实验组(CD4~+CD25~+调节性T细胞输注),对EAE大鼠进行神经功能评分及体质量测量,通过病理学HE染色和免疫组化观察脑和脊髓炎症浸润,实时荧光定量PCR(qPCR)检测鼠脑和脊髓IFN-γ、IL-17、IL-23和Foxp3 m RNA水平表达。结果实验组SD大鼠神经功能评分明显改善,体质量明显增加;与模型组比较,实验组神经症状和病理改变减轻,鼠脑和脊髓IFN-γ、IL-17、IL-23 mRNA表达下降,而Foxp3 mRNA表达增加(P0.05)。结论 CD4~+CD25~+调节性T细胞通过调节免疫系统的脑和脊髓IFN-γ、IL-17、IL-23和Foxp3 mRNA水平的表达对EAE起保护作用。     

慢性乙型病毒性肝炎患者外周血T淋巴细胞CD27和CD45RA表达的研究

目的分析慢性乙型病毒性肝炎患者外周血T淋巴细胞CD27和CD45RA的表达。方法采集分离健康人和慢性乙型病毒性肝炎患者外周血单个核细胞(PBMC),利用多种荧光标记抗体标记细胞表面分子,再用流式细胞仪检测CD8+T淋巴细胞表面CD27和CD45RA表达情况。结果31例慢性乙型病毒性肝炎患者CD8+CD45RA+CD27+T细胞占CD8+T细胞(29.03±13.18)%,低于28例健康对照组的(60.85±14.36)%,P<0.01。而CD8+CD45RA-CD27+T细胞占CD8+T细胞(30.31±24.11)%,显著高于健康对照组的(10.32±5.24)%,P<0.05。慢性乙型病毒性肝炎患者CD4+CD45RA+CD27+T细胞21.12±9.64%低于健康对照组的(60.89±17.93)%,P<0.01,而CD4+CD45RA-CD27+T细胞(54.28±18.75)%显著高于健康对照组的(27.16±9.24)%,P<0.01。结论健康人外周血CD8+和CD4+T淋巴细胞均以CD45RA+CD27+初始细胞表型为主,而慢性乙型病毒性肝炎患者外周血初始细胞减少,CD45RA-CD27+表型的T淋巴细胞明显增加。     

慢性乙型肝炎患者外周血CD8+/CD28+淋巴细胞及其亚型的研究

目的 探讨慢性乙型肝炎患者外周血CD8+/CD28+淋巴细胞及其亚型与其临床状态和HBV复制的关系.方法 采用流式细胞技术多色荧光分析法,检测研究对象的外周血CD8+淋巴细胞、CD45RO、CD45RA以及CD28的表达及HBV病毒载量.结果 ①慢性HBV携带组CD8+淋巴细胞CD28的表达率(10.64±5.09%)明显低于慢性乙肝组和正常对照组;而CD45RA和CD45RO的表达差异无统计学意义;②慢性乙肝组CD8+/CD45RO+/CD28+的表达(10.99±7.33%)明显高于正常对照组,而慢性乙肝组和慢性HBV携带组CD8+/CD45RA+/CD28+表达率均明显低于正常对照组;③HBeAg阴性慢性乙肝CD8+/CD45RO+/CD28+表达率明显高于阳性组,而CD8+/CD45RA+/CD28+表达率两组无差别.结论 慢性HBV携带者处于病毒携带状态可能与CD8细胞上协同分子CD28的表达低下有关;CD8+/CD45RO+/CD28+亚型淋巴细胞数的升高与慢性乙肝的病情进展及血清HBeAg转换有关.     

Foxp3~+ Treg、Th细胞迁移及ET-1与佐剂关节炎大鼠模型肺功能的关系

目的:观察佐剂关节炎(Adjuvant arthritis,AA)大鼠肺功能降低与辅助T细胞(Th)、调节T细胞(Treg)及Foxp3的关系。方法:将SD大鼠随机分为正常对照(NC)组和模型对照(MC)组,每组15只,向MC组大鼠右后足跖皮内注射弗氏完全佐剂0.1 ml致炎,复制成AA模型。致炎48 d后,采用小动物肺功能仪检测肺功能,酶联免疫吸附法检测内皮素(ET)-1、白细胞介素(IL)-10、γ干扰素(IFN-γ),免疫组化法检测肺组织IL-1β、IL-10表达,流式细胞仪测定Treg的表达,采用PCR与免疫印迹检测肺组织Foxp3表达。结果:与NC组相比,MC组大鼠IFN-γ、ET-1、IL-1β升高;肺功能参数50%肺活量的最大呼气流量(FEF50)、75%肺活量的最大呼气流量(FEF75)、最大呼气中期流量(MMF)、用力最大呼气流量(PEF)降低,IL-10、CD4+CD25+Foxp3+Treg、Foxp3表达降低(P<0.05或P<0.01);相关分析显示,AA大鼠肺功能参数FEF75、MMF分别与IFN-γ、Th1/Th2、IL-1β呈负相关,FEF50、PEF与ET-1呈负相关;PEF、FEF75分别与IL-10、Foxp3 mRNA、Foxp3蛋白呈正相关,FEF75与CD4+CD25+Foxp3+Treg呈正相关(P<0.05或P<0.01)。结论:AA大鼠肺功能下降可能是佐剂致炎后Th细胞分泌紊乱、细胞因子失衡、内皮细胞增多,使肺组织Foxp3表达抑制,进而CD4+CD25-T细胞转化成CD4+CD25+Treg受阻,最终导致RA肺功能降低。     

结直肠癌患者与健康受试者外周血CD45RA+/CD45RO+淋巴细胞表型分析

目的 分析结直肠癌患者与健康受试者外周血CD45RA+/CD45RO+系列T淋巴细胞表达的差异.方法 运用流式细胞术(FCM)检测2010年1月至2013年12月解放军总医院收治的109例结直肠癌患者(试验组)与64例健康受试者(对照组)外周血CD45RA+、CD45RO+、CD4+ CD45RA+、CD4+ CD45RO+T淋巴细胞亚群表达情况,统计分析试验组和对照组性别和年龄的分布是否存在差异,然后进一步分析CD45 RA等T淋巴细胞亚群与结直肠癌临床分期的关系.结果Ⅰ+Ⅱ期、Ⅲ期和Ⅳ期结直肠癌患者外周血CD45 RA+细胞百分率[三者分别为(56.23±7.75)％、(58.86±7.66)％和(59.02±9.71)％]明显高于对照组[(48.94±12.66)％],差异具有统计学意义(F=11.128,P＜0.001);Ⅲ期和Ⅳ期患者的CD45RO+细胞百分率[分别为(47.19±8.30)％和(45.41±10.45)％]则明显低于对照组[(53.43±11.75)％],差异具有统计学意义(F=5.817,P=0.00083);Ⅲ期和Ⅳ期患者CD45RA+/CD45RO+的比值(分别为1.32 ±0.46和1.43±0.63)明显高于对照组(1.00±0.47),差异具有统计学意义(F=6.986,P=0.000185);Ⅰ+Ⅱ期患者CD4+ CD45 RO+细胞百分率[(31.37±6.39)％]明显高于对照组[(27.49±7.19)％],差异具有统计学意义(F=2.368,P=0.009);Ⅳ期患者CD4+ CD45RA+/CD4+ CD45RO+的比值(0.66±0.39)明显高于Ⅰ+Ⅱ期的患者(0.49±0.23),差异具有统计学意义(F=1.812,P=0.029);各组之间CD4+ CD45RA+细胞百分率无明显统计学差异(F=0.637,P=0.592).结论 随着临床分期的增加,结直肠癌患者外周血CD45RA+细胞逐渐增加而CD45RO+细胞逐渐减少,反映出结直肠癌患者随着肿瘤的进展其免疫功能逐渐抑制、逐渐降低的动态过程;CD4+ CD45RA+细胞和CD4+ CD45RO+细胞在反映结直肠癌患者机体免疫功能方面不如CD45RA+细胞和CD45RO+细胞敏感.     

MOG诱导的实验性自身免疫性脑脊髓炎小鼠中枢及外周神经系统CD4~+ T及CD8~+ T调节性细胞变化

目的:观察实验性自身免疫性脑脊髓炎小鼠中枢及外周CD4+ CD25+调节性T细胞(CD4+ CD25+ Treg),CD8+ CD28-调节性T细胞(CD8+ CD28- Treg)表达的变化情况,并探讨相关的细胞免疫学机制。方法:雌性C57BL/6小鼠随机分为未使用髓鞘少突胶质细胞糖蛋白35-55(MEVGWYR-SPFSRVVHLYRNGK)(MOG35-55)免疫的对照组和使用MOG35-55免疫诱导的EAE小鼠模型组,采用临床症状评分记录小鼠行为学变化、HE染色观察CNS炎症细胞浸润及病理改变,使用流式细胞术(FCM)检测小鼠中枢及外周CD8+ CD28- Treg,CD4+ CD25+ Treg细胞表达水平。结果:MOG35-55诱导的EAE模型组动物出现典型的EAE临床行为学及病理学表现,FCM检测EAE模型组小鼠脾细胞CD4+ CD25+ Treg较对照组升高但无统计学差异,CD8+ CD28- Treg表达水平明显低于对照组(P0.01),EAE模型组中枢有CD4+ CD25+ Treg,CD8+CD28-Treg淋巴细胞的浸润,且CD4+ CD25+ Treg,CD8+ CD28- Treg在中枢的表达均高于外周,对照组中枢神经系统未检测到淋巴细胞浸润。结论:CD4+ CD25+ Treg,CD8+ CD28- Treg均参与调控EAE的病理过程,CD4+ CD25+ Treg,CD8+ CD28- Treg在EAE小鼠中枢及外周分布及变化的不同,提示其进入中枢神经系统(CNS)并参与调节中枢局部炎症。     

HIV/AIDS患者CD28在外周血CD4+、CD8+ T细胞上的表达变化

目的　研究国内HIV AIDS患者CD2 8在外周血CD4 + 、CD8+ T淋巴细胞上表达的变化 ,并探讨这些变化的临床意义。方法　用流式细胞仪检测 5 1例正常对照、14例HIV感染者和 36例AIDS患者的外周血CD4 + 、CD8+ T淋巴细胞表面的CD2 8分子的表达 ,用bDNA法检测 11例HIV感染者和 18例AIDS患者的血浆病毒载量。结果　CD4 + CD2 8+ T细胞的绝对计数与百分比、CD8+ CD2 8+T细胞的百分比均显示为正常对照组 >HIV感染组 >AIDS组 ;而CD8+ CD2 8+ T细胞的绝对计数显示HIV感染组和对照组显著大于AIDS组 ,HIV感染组与对照组间差异无显著性。CD4 + 、CD2 8+ CD4 + T淋巴细胞计数与血浆病毒载量显著负相关。结论　HIV AIDS患者外周血CD2 8在CD4 + 、CD8+ T淋巴细胞上表达随着病情进展而降低 ,反映了细胞免疫功能随着疾病进展损害逐渐加重 ,是判断病情进展的指标。     

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.