重症肌无力患者Foxp3~+CD4~+CD25~+调节性T细胞与AChRAb、Titin-Ab的相关研究

目的探讨重症肌无力(myasthenia gravis,MG)患者Foxp3~+CD4~+CD25~+调节性T细胞(Foxp3~+CD4~+CD25~+Treg)与乙酰胆碱受体抗体(AChRAb)及连接素抗体(Titin-Ab)之间的关系,进一步揭示MG的发病机制。方法采用酶联免疫吸附试验(ELISA)检测22例MG患者以及20名健康对照者血清AChRAb和Titin-Ab水平;采用流式细胞术(FCM)检测两组外周血中CD4~+CD25~+Treg的比例及其表达Foxp3的比例。结果 MG患者外周血CD4~+CD25~+Treg比例[(2.9±0.52)%]与健康对照组[(3.12±0.51)%]比较无统计学差异(P0.05);CD4~+CD25~+Treg细胞Foxp3表达比例为(37.24±9.57)%,低于健康对照组[(58.60±4.91)%](P0.01)。MG组CD4~+CD25~+Treg表达Foxp3比例与AChRAb、Titin-Ab水平[分别为(0.232±0.060)和(0.170±0.035)pg/mL]均呈负相关(r=-0.449,P0.05;r=-0.691,P0.01)。结论 Foxp3~+CD4~+CD25~+Treg细胞数目减少导致机体免疫功能缺陷是MG发病的重要环节。     

重症肌无力胸腺基质淋巴细胞生成素表达与CD4~+CD25~+Foxp3~+Treg细胞表型的研究

目的探索重症肌无力患者胸腺基质淋巴细胞生成素(TSLP)表达水平与CD4+CD25+Foxp3+调节性T细胞(Treg)表型的相关性。方法 MG组(16例经胸腺切除的MG患者)及对照组(23例先天性心脏病心脏手术后患者)取外周血单个核细胞,经CD4+CD25+抗体表面染色后加入破膜剂孵育,以Foxp3+抗体行胞内染色,以流式细胞技术检测CD4+CD25+Foxp3+Treg/CD4+T细胞比率;同时取两组患者对应的切除胸腺组织,以免疫组织化学法检测TSLP表达水平,并进行两组间比较;以Logistic回归分析方法分析TSLP阳性表达的Hassall小体计数与Treg细胞之间的相关性。结果CD4+CD25+/CD4+T细胞比率MG组〔(6.24±0.62)%〕与对照组〔(6.56±0.65)%〕无统计学差异(P>0.05),MG组CD4+CD25+Foxp3+Treg/CD4+T细胞比率〔(3.82±0.49)%〕较对照组〔(5.73±0.56)%〕明显降低(P<0.01);与对照组比较,MG组患者胸腺TSLP阳性面积大,染色深,且TSLP阳性的Hassall小体数目(6.81±2.17)明显低于对照组(18.87±3.06)(P<0.01)。MG组TSLP阳性表达的Hassall小体计数与Treg细胞表达量之间呈线性相关(R2=0.158,F=13.42,P<0.01)。结论 MG患者TSLP表达不足与胸腺Treg细胞发育过程中CD4+CD25+Foxp3+表型的表达缺陷呈正相关。     

抑郁症中糖皮质激素受体与CD4+CD25+调节性T细胞的关系及其所致免疫失衡机制的初步探讨

目的 研究抑郁症患者外周血细胞因子白介素-10(IL-10)、转化生长因子β(TG-β)的变化、CD4+CD25+调节性T细胞(Treg)的数量及其特征性标志叉头样转录因子P3(Foxp3)的表达与糖皮质激素受体(GR)的表达之间的关系,探讨抑郁症患者免疫失衡的可能机制.方法 纳入36例抑郁症患者和36名正常对照,根据Hamilton抑郁量表总分将患者划分为轻、中和重不同抑郁程度组;利用ELISA方法测定受试者外周血血清细胞因子IL-10、TGF-β浓度;逆转录-聚合酶链反应(RT-PCR)检测GR的α及β两种亚型(GRα、GRβ)、Foxp3 mRNA表达水平;免疫磁珠分离CD4+ CD25+ Treg,共聚焦显微镜观察Foxp3与GR在CD4+CD 25+ Treg上的共表达.结果 与正常对照组比较,患者组血清IL-10、TGF-β的水平降低(P＜0.05),外周血CD4+ CD25+ Treg数量及在CD4+T细胞中的比例明显少于对照组(P＜0.01),且重度抑郁组上述指标明显低于中度和轻度抑郁组(P＜0.01).抑郁各组单个核细胞GRamRNA和FoxP3 mRNA表达水平随抑郁程度而降低(P＜0.01),GRβmRNA却在重度抑郁组表达增加.共聚焦显微镜下可观察到重度抑郁患者CD4+CD25+Treg上GR与Foxp3表达显著减少.结论 糖皮质激素受体可能通过影响调节性T细胞的功能和数量在抑郁症患者免疫失衡的病理生理机制中发挥着重要的作用.     

重症肌无力患者外周血CD4+T细胞OX40的表达及作用机制研究

目的 分析重症肌无力(MG)患者外周血CD4+T细胞协同刺激分子OX40表达及其对FoxP3+CD4+CD25+调节性T细胞(Treg)的调控作用,初步探讨OX40在MG免疫学发病中的作用机制.方法 以流式细胞技术检测42例MG患者及38名健康对照的外周血OX40+CD4+T细胞、FoxP3+CD4+CD25+Treg表达水平,比较OX40表达在MG患者不同临床疾病状态、Osserman分型、临床绝对评分、胸腺病理类型等情况下的差异,并分析OX40对FoxP3+CD4+CD25+Treg细胞的影响.结果 (1) MG患者外周血OX40+CD4+T细胞占淋巴细胞百分比高于健康对照组(P<0.01).(2)MG患者OX40+CD4+T细胞百分比在发作或加重期高于缓解期(P＜0.05);在临床绝对评分呈中、重度患者OX40+CD4+T细胞百分比高于轻度患者(均P＜0.05);Osserman Ⅱ、Ⅳ型患者OX40+CD4+T细胞百分比高于Ⅰ型患者(均P＜0.05);胸腺增生及胸腺瘤患者OX40+CD4+T细胞百分比高于胸腺正常患者(P＜0.05,P＜0.01).(3)MG患者外周血OX40+CD4+T细胞百分比与FoxP3+CD4+CD25+Treg细胞百分比呈负相关(r=-0.843,P=0.01).结论 协同刺激分子OX40参与MG发病,可能通过抑制FoxP3+CD4+CD25+Treg细胞生成发挥作用.     

雌二醇对实验性自身免疫性脑脊髓炎调节性T细胞及细胞因子的影响

目的 探讨雌二醇(E2)对实验性自身免疫性脑脊髓炎(EAE)大鼠调节性T细胞及细胞因子的影响.方法 将大鼠随机分为E2干预组和EAE对照组,记录其临床评分, 测定外周血CD4+CD25+、CD4+CD25+Foxp3+ T细胞水平以及TNF-α、IL-12表达水平,并观察腰膨大处炎细胞浸润情况.结果 (1)E2干预组发病率仅为30% ,低于EAE对照组(100%), 且发病高峰延迟;临床评分E2干预组[(1.8±1.3)分]比EAE对照组[(3.4±0.5)分]低, 差异有统计学意义(P<0.05);(2)E2干预组CD4+CD25+/CD4+ T细胞比值 (5.6±0.9)、CD4+CD25+Foxp3+/CD4+CD25+ T细胞比值(9.3±1.0)均高于EAE对照组[分别为(4.4±0.9)与(7.6±0.8)], 差异有统计学意义(均P<0.05);(3)血管"套袖"样改变EAE对照组较E2干预组明显;(4)E2干预组TNF-α及IL-12表达明显低于EAE对照组, 差异有统计学意义(均P<0.05).结论 E2可能通过改变调节性T细胞比例及细胞因子表达参与EAE免疫调节过程, 推测EAE临床症状缓解可能也与此机制相关.     

载脂蛋白E拟肽对实验性自身免疫性脑脊髓炎小鼠脑脊髓CD4+、CD8+T淋巴细胞表达的影响

目的 探讨载脂蛋白(Apo)E拟肽对实验性自身免疫性脑脊髓炎(EAE)小鼠脑脊髓CD4+、CD8+T淋巴细胞表达的影响.方法 40只C57BL/6J雌性小鼠随机分成EAE组、EAE治疗组、正常对照组、正常治疗组;采用髓鞘少突胶质细胞糖蛋白制备的完全抗原诱导EAE模型小鼠.免疫诱导次日,EAE治疗组和正常治疗组小鼠每隔2d皮下注射ApoE拟肽,EAE组和正常对照组小鼠皮下注射等量的生理盐水.免疫诱导后各组每日进行神经功能缺损评分(NDS);35 d后用免疫组化检测各组小鼠脑脊髓CD4+T细胞、CD8+T细胞的表达.结果 EAE治疗组NDS的峰值及终末评分显著低于EAE组(均P＜0.05).与正常对照组及正常治疗组比较,EAE组大脑、脑干和脊髓中CD4+T细胞数明显增高,大脑CD8+T细胞数明显增高(均P＜0.05).EAE治疗组小鼠大脑、脑干、脊髓组织CD4+T细胞表达显著低于EAE组(均P＜0.05);两组间CD8+T细胞表达水平的差异无统计学意义.结论 ApoE拟肽可抑制CD4+T细胞的表达,减轻免疫炎症反应,对EAE小鼠有神经保护作用;而对CD8+T细胞的表达无明显影响.     

应用供体抗原特异性CD4+CD25+ Treg细胞延长大鼠移植肾的存活

背景：随着磁分选技术的完善,体外分选、扩增足量的对移植抗原具有特异性的细胞已成为可能,但就其在体内应用剂量及免疫耐受的效能问题目前鲜有报道。 目的：探索供体抗原特异性CD4+CD25+Treg细胞在体内应用诱导移植免疫耐受的量效关系。 方法：以SD大鼠为供体、Wistar大鼠为受体,建立同种异体肾移植动物模型;体外分选、富集Wistar大鼠脾脏CD4+CD25+Treg细胞,并诱导其对SD大鼠供体抗原的特异性表型;根据不同数量(2×105、5×105、1×106、2×106)供体抗原特异性CD4+CD25+Treg细胞在肾移植中单剂量尾静脉注射,并以未注射组为对照。术后15 d分析移植肾脏存活状况。术后4,9,15 d采血检测各组肌酐水平,同时进行移植肾脏病理检查,按照Banff Schema标准进行诊断,并根据Watanabe的方法进行半定量评分。 结果与结论：术后15 d内对照组死亡率最高83.3%,2×105组次之66.7%,2×106组为58.3%,5×105组为33.3%,1×106组则全部存活;各实验组术后4,9,15 d血肌酐水平均明显低于对照组(P < 0.05,P < 0.01);术后第9,15天,2×105组、5×105组血肌酐水平均明显高于1×106组、2×106组(P < 0.05);术后第4,9,15天移植肾脏病理检查的半定量评分结果显示,各时间段5×105组、2×105组与对照组间差异无显著性意义,各时间段1×106组与2×106组优于对照组 (P < 0.05)。结果初步证实供体抗原特异性CD4+CD25+Treg细胞受体内应用能够改善大鼠移植肾功能,延长移植肾存活时间,1×106为相对理想的单次应用剂量。     

实验性自身免疫性脑脊髓炎大鼠血CD4+CD25+T细胞的研究

目的探讨实验性自身免疫性脑脊髓炎(EAE)动物模型血CD4 CD25 T细胞的变化及其意义。方法以豚鼠全脊髓匀浆(GPSCH)为抗原免疫Wistar大鼠,建立EAE的动物模型,采用三色流式细胞仪检测EAE和正常大鼠外周血CD4 CD25 T细胞的细胞数并进行比较;通过观察大鼠行为学及脑和脊髓的病理改变确定EAE。结果EAE模型大鼠的成功率为48.9%,EAE大鼠外周血CD4 CD25 T淋巴细胞数(5.29±4.00)显著低于正常对照组(12.61±2.24)(P<0.01)。结论EAE大鼠血CD4 CD25 T细胞数明显减少,CD4 CD25 T淋巴细胞对神经系统脱髓鞘疾病是一种保护因子。     

CD4~+、CD25~+、CD127 low调节T细胞及CD16~+、CD56NK细胞在脑梗死急性期患者外周血中的表达及其关系

目的探讨脑梗死(CI)患者外周血中CD4+、CD25+、CD127 low调节T细胞及CD16+、CD56NK细胞的百分比变化及两者在CI患者免疫反应中的相互作用机制。方法采用流式细胞术检测50例急性CI患者(发病2d)外周血中CD4+、CD25+、CD127 low调节T细胞及CD16+、CD56NK细胞的表达水平,并与健康对照组进行比较。结果急性CI患者(发病2d)外周血中的CD4+、CD25+、CD127 low调节T细胞的表达水平低于健康对照组,而CD16+、CD56NK细胞的数量则明显高于健康对照组(p<0.05)。结论急性CI患者发病2d,CD16+、CD56NK细胞表达水平上升,而CD4+、CD25+、CD127 low调节性T细胞表达明显低于健康对照组,说明CD4+、CD25+、CD127 low调节性T细胞和CD16+、CD56NK细胞是促进CI发生的原因之一。     

重症肌无力患者外周血Foxp3和CD152表达变化及其相关性分析

目的研究重症肌无力(MG)患者经全胸腺切除治疗外周血中调节性T细胞(CD4~+ CD25~+ Treg)中Foxp3及CD152(CTLA-4)的表达情况。方法采集重症肌无力经手术切除胸腺患者50例术前和术后6个月外周血为实验组,对照组为25例健康志愿者的外周血。应用流式细胞分析方法检测患者手术前后和健康志愿者外周血中的调节性T细胞Foxp3及CD152(CTLA-4)的表达情况。结果患有MG患者术前外周血中调节性T细胞Foxp3及CD152(CTLA-4)表达水平与对照组相比显著降低(P0.05);全胸腺切除6个月后CD4~+ CD25~+ Foxp3~+ Treg细胞及CD152(CTLA-4)表达比例与手术前比较升高(P0.05),与健康对照组比较水平低(P0.05);调节性T细胞中Foxp3表达水平与CD152(CTLA-4)表达水平呈现一定的正相关性(P0.001)。结论重症肌无力患者外周血调节性T细胞中Foxp3和CD152(CTLA-4)表达水平较低,手术治疗能够明显提高Foxp3及CD152(CTLA-4),然而与正常人比较还不能达到正常的水平,为重症肌无力发病机制与胸腺切除治疗提供了理论依据。     

Paralysis of CD4(+)CD25(+) regulatory T cell response in chronic autoimmune encephalomyelitis

Increasing evidence strongly suggest that CD4(+)CD25(+) regulatory T (Treg) cells play a pivotal role in suppressing the development of autoimmune diseases. However, it remains poorly understood how these cells are involved in the persistence of, or recovery from, the diseases. In the present study, we examined the role of CD4(+)CD25(+) Treg cells in chronic EAE and compared the results with those obtained in acute EAE. In EAE lesions, CD25(+) cells decreased rapidly at the beginning of chronic EAE, whereas these cells were maintained at high levels during the recovery from acute EAE. The number of Foxp3(+)CD4(+)CD25(+) Treg and levels of Foxp3 mRNA in the lymphoid organ were significantly lower in chronic EAE. Importantly, the regulatory function of individual CD4(+)CD25(+) Treg cells was maintained in animals with chronic EAE. Furthermore, adoptive transfer of activated CD4(+)CD25(+) Treg cells suppressed the development of chronic EAE. These findings suggest that impairment of the CD4(+)CD25(+) Treg response is critical for development of chronic autoimmune diseases, and can be adjustable by autologous Treg transplantation.     

Functional assay for human CD4+CD25+ Treg cells reveals an age-dependent loss of suppressive activity

CD4+CD25+ regulatory T cells (Treg cells) prevent T cell-mediated autoimmune diseases in rodents. To develop a functional Treg assay for human blood cells, we used FACS- or bead-sorted CD4+CD25+ T cells from healthy donors to inhibit anti-CD3/CD28 activation of CD4+CD25- indicator T cells. The data clearly demonstrated classical Treg suppression of CD4+CD25- indicator cells by both CD4+CD25(+high) and CD4+CD25(+low) T cells obtained by FACS or magnetic bead sorting. Suppressive activity was found in either CD45RO- (naive) or CD45RO+ (memory) subpopulations, was independent of the TCR signal strength, required cell-cell contact, and was reversible by interleukin-2 (IL-2). Of general interest is that a wider sampling of 27 healthy donors revealed an age- but not gender-dependent loss of suppressive activity in the CD4+CD25+ population. The presence or absence of suppressive activity in CD4+CD25+ T cells from a given donor could be demonstrated consistently over time, and lack of suppression was not due to method of sorting, strength of signal, or sensitivity of indicator cells. Phenotypic markers did not differ on CD4+CD25+ T cells tested ex vivo from suppressive vs. nonsuppressive donors, although, upon activation in vitro, suppressive CD4+CD25+ T cells had significantly higher expression of both CTLA-4 and GITR than CD4+CD25- T cells from the same donors. Moreover, antibody neutralization of CTLA-4, GITR, IL-10, or IL-17 completely reversed Treg-induced suppression. Our results are highly consistent with those reported for murine Treg cells and are the first to demonstrate that suppressive activity of human CD4+CD25+ T cells declines with age.     

Interferon-beta-1a treatment increases CD56 natural killer cells and CD4+CD25+ Foxp3 expression in subjects with multiple sclerosis

Disease modifying effects of interferon (IFN)-β therapy in patients with multiple sclerosis (MS) may be mediated in part through enhanced immunoregulation by the CD56^bright subpopulation of natural killer (NK) cells and by Foxp3+ (not italicized) CD4+CD25+ regulatory T cells (Treg). We found that IFN-β-1a(IM) treatment of relapsing–remitting (RR)MS subjects over 12 months significantly increased both percentage of CD56^bright NK cells and Foxp3 mRNA expression compared to baseline values, untreated RRMS subjects and healthy controls (HC). This striking enhancement of two prominent immunoregulatory pathways lends support to the idea that beneficial effects of IFN-β-1a in MS include control of pernicious autoimmunity.     

Glucocorticoids increase CD4CD25 cell percentage and Foxp3 expression in patients with multiple sclerosis

Objectives – To determine whether percentages of CD4⁺CD25^high T cells (a group of regulatory T cells, Treg) differ in patients with multiple sclerosis (MS) in relapse vs remission after glucocorticoid treatment and whether treatment for relapses changes Treg population and the expression of Foxp3, a key Treg‐associated molecule. Materials and methods – Peripheral blood mononuclear cells (PBMC) were obtained from 20 patients with MS during relapse, just before and 2 days after starting steroid treatment (i.v. methylprednisolone 1 g/day for 3 days) and then 6 weeks after treatment. CD4⁺CD25^hi cells were analysed by using flow cytometry. Cytokines were measured by using an ELISA and Foxp3, CD3 and CD25 expression by using quantitative real‐time PCR. Results – The percentage of CD4⁺CD25^hi cells, plasma IL‐10 and Foxp3/CD3 ratio increased 48 h after methylprednisolone initiation and returned to baseline values by 6 weeks post‐treatment. Conclusions – Results suggest that glucocorticoids increase Treg cell functional molecules and percentages. This may be a mechanism whereby steroids expedite recovery from MS relapses.     

High cell surface expression of CD4 allows distinction of CD4(+)CD25(+) antigen-specific effector T cells from CD4(+)CD25(+) regulatory T cells in murine experimental autoimmune encephalomyelitis

Analysis of T regulatory cells (Treg) and T effector cells (Teff) in experimental autoimmune encephalomyelitis is complicated by the fact that both cell types express CD4 and CD25. We demonstrate that encephalitogenic T cells, following antigen recognition, up-regulate cell surface expression of CD4. The CD4(high) sub-population contains all of the antigen response as shown by proliferation and cytokine secretion, and only these cells are capable of transferring EAE to naive animals. On the other hand, a FACS separable CD25(+) sub-population of cells displayed consistent levels of CD4 prior to and after antigen stimulation. These cells displayed characteristics of Treg, such as expressing high levels of the Foxp3 gene and the ability to suppress mitogenic T cell responses.     

CD25 regulatory T cells determine secondary but not primary remission in EAE: impact on long-term disease progression

Multiple sclerosis (MS) is often characterized by several relapses and remissions during long-term disease, but neither the responsible cells nor the mechanisms are known to date. Using an animal model of multiple sclerosis, relapsing experimental autoimmune encephalomyelitis (R-EAE) CD4+CD25+ Treg cells expressing Foxp3 and CTLA-4 intracellularly and T lymphocytes expressing surface CTLA-4 were identified in the CNS. The first remission occurred even after depletion of Treg cells, but secondary remissions from EAE were ablated. Despite the unaltered first remission autoantigen rechallenge revealed already an amplified cytokine response during acute phase. These results indicate that the cellular composition during first attack of MS predicts long-term disease progression.     

Secondary progressive in contrast to relapsing-remitting multiple sclerosis patients show a normal CD4+CD25+ regulatory T-cell function and FOXP3 expression

Accumulating evidence indicates an immunosuppressive role for CD4(+)CD25(+) regulatory T cells (Tregs) in autoimmune diseases. Although an impaired Treg function in patients with relapsing-remitting multiple sclerosis (RR-MS) has been reported recently, no information is available so far about Treg function in the progressive stage of the disease. In the present study, the phenotypic and functional characteristics of CD4(+)CD25(+) T cells isolated from the peripheral blood of patients with RR-MS and secondary progressive multiple sclerosis (SP-MS) were investigated. No significant quantitative or phenotypic abnormalities in CD4(+)CD25(+) T cells from RR- and SP-MS patients were detected. However, whereas a reduced suppressor function of CD4(+)CD25(+) T cells toward proliferation and interferon-gamma production of CD4(+)CD25(-) responder T cells was found in RR-MS patients, SP-MS patients showed a normal Treg function. The suppressive capacity of MS-derived CD4(+)CD25(+) T cells was correlated with disease duration but not with age, indicating that Treg function is more affected in the early phase of the disease process. Consistently with the suppressive capacity, CD4(+)CD25(+) T cells from SP-MS patients showed normal levels of FOXP3 mRNA in contrast to RR-MS patients that had a reduced FOXP3 expression. These data are the first to demonstrate differences in function and FOXP3 expression of CD4(+)CD25(+) T cells from patients with RR- and SP-MS.     

IL-21 receptor expression determines the temporal phases of experimental autoimmune encephalomyelitis

The IL-21 receptor (IL-21R) consists of a unique subunit and a common gamma chain (gamma(c)) that is shared with other cytokines including IL-2, IL-4, IL-7, and IL-15. The interaction between IL-21 and IL-21R results in significant effects on both innate and adaptive immune responses. In this study we examined the influence of IL-21R deficiency (IL-21R(-/-)) on the development of experimental autoimmune encephalomyelitis (EAE), an animal model of human multiple sclerosis (MS). IL-21R(-/-) mice developed EAE earlier and more severe neurological impairment than control mice, yet those mice could effectively recover from neurological deficits. The impact on EAE initiation by IL-21R deficiency was associated with a defect of CD4(+)CD25(+) T regulatory (Treg) cells and a down-regulated expression of Foxp3. The recovery from IL-21R(-/-) EAE was correlated with an expansion of Treg cells as well as an organ-specific redistribution of NK cells. These results suggest that a temporal influence of IL-21 on the activity of immunoregulatory circuits can be important in the modulation of the course of the autoimmune disease.