CD4+CD25+调节性T细胞与肿瘤免疫

CD4+CD25+调节性T细胞(CD4+CD25+Treg)是维持机体免疫耐受的一种重要因素。它组成性表达IL-2受体α链(CD25),主要的功能是抑制自身反应性T细胞的活化和功能,调节机体对抗原的免疫应答,从而使机体避免发生自身免疫病。近年来研究表明,Treg也可能通过相同的机制削弱机体的抗肿瘤效应。Treg介导的免疫抑制是肿瘤逃逸的原因之一。针对Treg进行肿瘤免疫治疗是一项可行的策略。     

CD4+CD25+调节性Treg细胞与急性移植物抗宿主病

CD4+CD25+Treg细胞是调节性T细胞的一个重要亚群,具有免疫无能和免疫抑制的特性,在防止自身免疫病发生、诱导移植耐受及调节肿瘤免疫方面起着重要作用。急性移植物抗宿主病(aGVHD)是异基因造血干细胞移植后最严重的并发症。近年来,有关CD4+CD25+Treg细胞与aGVHD关联性的研究取得了很大的进展,特别是该类细胞可有效地降低aGVHD的发生及作为aGVHD风险预测的一项重要指标。本文就CD4+CD25+Treg细胞的特性、免疫调节作用机制及CD4+CD25+Treg细胞与aGVHD的关联性的一些研究进展作一综述。     

CD4+CD25+T细胞与移植免疫耐受

调节性T细胞是机体维持自身耐受的重要组成部分.CD4+CD25+T细胞以持续高表达CD25为特征,可通过细胞间直接接触或分泌TGF-β、IL-10来发挥抑制功能.它广泛参与自身免疫耐受、肿瘤免疫、移植免疫.现就其发育、特性、发挥功能的机制以及在移植免疫耐受中的作用和应用前景作一综述.     

多发性骨髓瘤患者外周血CD4~+CD25~+和CD8~+CD28~-调节性T细胞研究

目的:探讨CD4~+CD25~+和CD8~+CD28~-调节性T细胞(Tregs)在多发性骨髓瘤(MM)患者外周血中的变化及意义.方法:采用流式细胞术检测38例MM患者及20例健康对照外周血CD4~+CD25~+和CD8~+CD28~-Tregs水平.分别采用溴甲酚绿法、透射免疫比浊法测定患者血清白蛋白(Alb)、β2-微球蛋白(β2-MG).结果:初诊MM患者外周血CD4~+CD25~(+/high)、CD4~+CD25~(high)CD127~(low)及CD8~+CD28~-Tregs比率均明显升高;CD4~+CD25~(+/high)和CD4~+CD25~)(high)CD127~(low)Tregs比率在各临床分期均较对照组升高,随分期增高呈现增加趋势,且CD4~+CD25~(high)和CD4~+CD25~(high)CD127~(low)Tregs在Ⅲ期患者显著高于Ⅰ期患者;CD8~+CD28~(-Tregs)在Ⅱ、Ⅲ期显著高于正常对照,且Ⅱ期高于Ⅰ期,Ⅲ期高于Ⅱ期,逐期递增,而在Ⅰ期与对照组比较无显著差异;CD4~+CD25~(+/high)和CD4~+CD25~(high)CD127~(low)Tregs比率在进展期和稳定期均较对照组升高,但两期之间比较无明显差异,而CD8~+CD28~-Tregs在进展期高于稳定期及对照组,稳定期和对照组间比较无明显差异;CD4~+CD25~(high)Tregs和CD4~+CD25~(high)CD127~(low)Tregs比率与Alb水平均呈负相关.结论:MM患者体内存在CD4~+CD25~+Tregs和CD8~+ CD28~-Tregs异常增加,可能是MM免疫逃逸的一个重要机制,这些变化同临床分期、病情进展及预后存在一定程度相关性.     

肺部恶性肿瘤患者CD4+CD25+Treg等指标的临床测定及意义

目的:探讨研究肺部恶性肿瘤患者CD4+ CD25+调节性T细胞(Treg)等指标的临床测定及意义.方法:对我院2008-12/2010-08呼吸科或胸外科收治的86例肺癌患者为研究对象作为研究组,与本院同期收治的门诊体检健康人群81例作为对照组进行了对比研究.结果:研究组患者的外周血CD4+ CD25+ Treg占CD4 +T细胞的比例水平显著高于对照组健康人群且具有统计学差异.对于不同临床分期的肺癌患者CD4+ CD25+ Treg水平比较发现,Ⅰ～Ⅱ期患者较对照组高但无统计学差异,而Ⅲ期、Ⅳ期患者则显著高于对照组与Ⅰ～Ⅱ期患者水平.对于不同病理类型的肺癌患者外周血CD4+CD25+ Treg水平对比发现,腺癌、鳞癌及小细胞癌患者显著高于对照组,并具有显著的统计学差异.结论:CD4+ CID25+Treg的水平与肺癌的进展密切相关,同时还与肿瘤分期存在直接关联,通过抑制肿瘤免疫可以使得肿瘤发生免疫逃逸,进而提示去除人的CD4+ CD25+Treg或是一种有效的治疗肿瘤的免疫方法.     

癌灶CD4~+CD25~+和CD8~+ T细胞亚群与卵巢浆液性癌患者生存期相关

检测卵巢浆液性癌患者癌组织中CD4+CD25+及CD8+T细胞的数目,探讨其两种T细胞介导的免疫功能对疾病发展及预后的影响。免疫组织化学双标及单标的染色方法检测41例卵巢浆液性癌患者手术切除癌组织标本中CD4+CD25+和CD8+T细胞的数目。结果显示,癌灶中CD4+CD25+T淋巴细胞为(19.95±11.50)个/10HPF,CD8+T淋巴细胞为(43.46±16.69)个/10HPF。生存分析发现高CD4+CD25+T细胞组患者总生存期较低CD4+CD25+T细胞组缩短,差异有显著性(P<0.05);而高CD8+T细胞组患者总生存期与低CD8+T细胞组相比延长,且差异有显著性(P<0.05),此外两种T细胞数目与患者年龄、病理分级、临床分期、腹水细胞学及淋巴结转移等临床病理因素均无关(P>0.05)。结果表明,卵巢浆液性癌中高CD4+CD25+T细胞提示患者预后不良,可能与CD4+CD25+T细胞介导的免疫抑制导致肿瘤免疫逃逸有关;癌组织中高CD8+T细胞提示患者预后较好,两种T细胞对卵巢浆液性癌预后的评估有重要的价值,同时可以通过阻断CD4+CD25+T细胞的免疫抑制作用改善卵巢浆液性癌患者的预后,为卵巢癌治疗提供靶目标。     

天然CD4+CD25+Treg细胞的研究进展

天然CD4+ CD25+ Treg细胞在针对自身抗原和外来抗原的免疫应答中起关键控制作用,其缺乏或功能性的缺陷将导致多重病理性的失调.本文就近年在其产生、作用机制以及与免疫耐受的诱导关系等方面的研究进展进行了综述.     

CD4+CD25+调节性T细胞参与肿瘤免疫逃逸的研究进展

CD4~+CD25~+调节性T细胞(regulatory T cells,Treg)是机体行使负性免疫调节的重要载体,在生理病理的诸多方面都有重要意义。本文旨就其与肿瘤的关联、介导逃逸的机制、细胞来源以及可能的临床运用作一综述。     

诱导CD4+CD25+自然调节性T细胞发育的免疫识别

CD4+ CD25+ 自然调节性T细胞(nTreg)对维持自身免疫耐受极为重要,了解其发育途径具有重大理论和实用价值.最近一些证据表明在胸腺内nTreg的发育可能由不同于常规CD4+ T细胞发育的免疫受体刺激类型诱导,存在特殊的细胞内信号转导途径.这提示CD4+T细胞的不同免疫识别类型或机制在T细胞分化或免疫功能形成中有重要作用,并为深入理解复杂的免疫现象提供了一种新观念.     

105 CD4+CD25+调节性T细胞和肿瘤免疫

近期研究发现一个有独特免疫调节功能的T细胞亚群CD4+CD25+调节性T细胞,不仅能抑制自身免疫性疾病发生,还可能参与肿瘤免疫的调节.这群细胞具有免疫无能和免疫抑制特性,通过与细胞直接接触发挥作用,而不依赖于其分泌的细胞因子.肿瘤环境中CD4+CD25+调节性T细胞比例增加,导致肿瘤免疫失调,去除这群细胞可有效诱导肿瘤免疫,为肿瘤治疗提供了一种新的方法.     

Absence of CD4+CD25+ regulatory T cells is associated with a loss of regulation leading to increased pathology in Helicobacter pylori-infected mice

Helicobacter pylori induces symptomatic chronic gastritis in a subpopulation of infected individuals. The mechanism(s) determining the development and severity of pathology leading to symptoms are not fully understood. In a mouse model of H. pylori infection we analysed the influence of immunoregulatory CD4+CD25+ T cells on H. pylori colonization and gastritis. Athymic C57BL/6 nu/nu mice were reconstituted with (a) lymph node (LN) cells (b) LN cells depleted of CD25+ T cells (CD25(-) LN) or (c) not reconstituted at all. Mice were then infected orally with 3 x 10(8)H. pylori SS1 bacteria. At 2 and 6 weeks after the inoculation there was a significant (P < 0.001) reduction in H. pylori colonization in athymic mice transferred with CD25(-) LN cells compared to mice transferred with LN cells. Colonization was still reduced at 12 weeks after inoculation. Mice transferred with CD25(-) LN cells showed an earlier onset and increased severity of gastritis as compared to mice receiving LN cells. Splenic cells isolated from mice receiving CD25(-) LN cells produced the highest level of IFN-gamma on stimulation with H. pylori antigens in vitro, had a higher H. pylori-specific DTH response and increased infiltration of CD4+ T cells and macrophages in the gastric mucosa. Athymic mice not transferred with T cells had persistent high H. pylori colonization and displayed a normal gastric epithelium without inflammatory cells. In conclusion, CD4+CD25+ cells reduce immunopathology in H. pylori infection, possibly by reducing the activation of IFN-gamma producing CD4+ T cells, even at the expense of a higher H. pylori load in the gastric mucosa.     

B cells pulsed with Helicobacter pylori antigen efficiently activate memory CD8+ T cells from H. pylori-infected individuals

Helicobacter pylori infection causes chronic gastritis that may progress to peptic ulcers or gastric adenocarcinoma and thereby cause major world-wide health problems. Previous studies have shown that CD4+ T cells are important in the immune response to H. pylori in humans, but the role of CD8+ T cells is less clear. In order to study the CD8+ T cell response to H. pylori in greater detail, we have evaluated efficient conditions for activation of CD8+ T cells in vitro. We show that H. pylori-reactive CD8+ T cells can be activated most efficiently by B cells or dendritic cells pulsed with H. pylori antigens. We further show that the majority of CD8+ T cells in H. pylori-infected gastric mucosa are memory cells, and that memory CD8+ T cells sorted from peripheral blood of H. pylori-infected individuals respond 15-fold more to H. pylori urease compared to memory cells from uninfected subjects. We conclude that CD8+ T cells do participate in the immune response to H. pylori, and this may have implications for the development of more severe disease outcomes in H. pylori-infected subjects.     

Deficiencies in CD4+ and CD8+ T cell subsets in ataxia telangiectasia

Chronic sinopulmonary infections that are associated with immunodeficiency are one of the leading causes of death in the multi-systemic disease ataxia telangiectasia (AT). Immunological investigations of AT patients revealed a broad spectrum of defects in the humoral and the cellular immune system. Based on their important role in host defence the aim of our study was an extensive analysis of cell distribution and function of CD4+ and CD8+ T lymphocytes and NK cells. We found that naive (CD45RA+) CD4+ lymphocytes, as well as CD8+/CD45RA+ lymphocytes, are decreased, whereas NK cells (CD3-/CD16+CD56+) are significantly elevated in AT patients. In our culture system proliferation and cytokine production was normal in purified memory (CD45RO+) lymphocytes after stimulation with phorbol-12,13-dibutyrate (PBu2) and after PHA activation, indicating that differences in proliferation and cytokine production are due solely to reduced numbers of CD45RA+ lymphocytes. However, activation, and especially intracellular interferon production of AT lymphocytes, seem to follow different kinetics compared to controls. In contrast to polyclonal activation, stimulation via the T cell receptor results consistently in a reduced immune response. Taken together, our results suggest that deficiency of immunocompetent cells and an intrinsic immune activation defect are responsible for the immunodeficiency in AT.     

CD4~＋ CD25~＋ Foxp3~＋调节性T细胞与自身免疫性疾病

自身免疫性疾病系由于机体免疫系统失衡,产生针对自身组织的免疫应答并导致自身组织、器官损害的一类疾病。调节性T淋巴细胞（regulatory T cell,Treg）具有免疫应答低下和免疫抑制特性,在维持机体免疫耐受和免疫应答稳态方面具有非常重要的作用,Treg的异常与多种自身免疫性疾病有关[1]。Foxp3特异性表达于CD4＋CD25＋Treg细胞,与其发育、成熟以及抑制功能关系密切。但是目前关于该转录因子的表达调控机制却不清楚。本文拟就CD4＋CD25＋Foxp3 Treg细胞的研究进展及与多种自身免疫性疾病的关系作一综述。     

CD4+ CD25+调节性T细胞在流产中的研究进展

CD4+CD25+调节性T细胞(Tr)是一个具有独特免疫调节功能的T细胞亚群.Tr免疫学特性主要在于抑制自身反应性T细胞的活化,并参与外周免疫耐受,对维持机体内环境的稳定起重要作用.Tr在流产中发挥重要的免疫调节作用.     

CD4+CD25+FoxP3+调节T细胞抑制肺结核患者特异细胞免疫

  目的 了解结核患者外周血中CD4+CD25+FoxP3+调节T细胞在抑制结核患者结核特异细胞免疫反应中的作用。 方法 使用细胞分离、流式细胞分析、细胞增殖和细胞因子测定等方法,比较结核患者及健康正常人群外周血中CD4+CD25+FoxP3+调节T细胞的量及功能特征的差异。 结果 结核患者外周血中CD4+CD25+FoxP3+调节T细胞数占CD4+细胞总数的比例显著高于健康正常人群;在BCG及ESAT-6的刺激下,结核患者外周血单个核细胞增殖能力和产生γ-干扰素的能力比健康正常人群明显增强。在BCG刺激下,结核患者外周血CD4-细胞产生γ-干扰素(1289.62±519.01)及白介素-10(1045.40±534.12)的能力比结核患者外周血BPMCs细胞产生γ-干扰素(624.50±261.13)及白介素-10(377.00±249.56)的能力显著增强(均p<0.05);在BCG及ESAT-6的刺激下,结核患者外周血CD4+CD25+调节T细胞显著抑制结核患者外周血CD4+CD25-细胞产生γ-干扰素及白介素-10。 结论 结核患者CD4+CD25+FoxP3+调节T细胞数量增多,抑制结核患者结核特异细胞免疫反应功能增强,可能与结核的发生、发展及转归有密切关系。     

CD8+调节性T细胞及其应用的研究进展

CD8+T淋巴细胞的亚群不仅具有细胞毒性作用,还能调节机体的免疫反应.具有免疫抑制作用的CD8+调节性T细胞(Tr)能有效阻断过强的免疫应答,维持机体的免疫稳态.随着医学科学的不断发展,近年来对CD8+Tr的分型、作用机制及其参与调节自体免疫、器官移植耐受、肿瘤免疫和感染免疫应答等方面的研究取得了巨大进展.