T regulatory cells as an immunotherapy for transplantation

Advances in immunosuppressive therapies have made tissue and organ transplantation a common procedure in clinical medicine. However, true donor and recipient tolerance is not regularly achieved and almost all transplant recipients continue to require immunosuppressants throughout life, which is associated with side effects of the drugs. The identification and characterisation of regulatory T cells (Tregs) has recently opened up exciting opportunities for new ways of adoptive immunotherapy in transplantation. CD4⁺CD25⁺ Tregs of thymic origin have been shown to be key regulators of unseasoned immune responses in mice and in humans, preventing graft-versus-host disease and organ graft rejection in the transplantation setting. Although these cells can be found in the peripheral blood of healthy individuals, their isolation to a satisfying degree of purity is time-consuming and ineffective. Therefore, a variety of different methods to expand or induce regulatory T cells ex vivo have been advocated. Antigen-specific activation of Tregs is a prerequisite for their optimal function, making the design of new strategies to create and expand antigen-specific Tregs highly desirable. This review will focus on recent advances achieved in the field of transplantation tolerance using naturally occurring Tregs (CD4⁺CD25⁺), as well as other Tregs, and will discuss future applications of these cells in immunotherapy.     

T淋巴细胞与肝移植免疫耐受

背景：肝移植排斥反应的发病机制主要是T细胞介导的免疫应答,具有调节细胞功能的高活性、多功能的低分子蛋白质即细胞因子在器官移植排斥反应和免疫耐受中发挥着重要作用。目的：就T淋巴细胞与肝移植后免疫耐受的关系及研究现状作一综述。方法：由第一作者检索Medline数据库及维普医学数据库1995年1月至2013年6月有关肝移植后免疫状态与T淋巴细胞及其细胞因子作用的文献。以“liver transplantation,jmmune tolerance,rejection,Tlymphocytes”为英文检索词,“肝移植,排斥反应,免疫耐受,T淋巴细胞”为中文检索词,排除重复研究类文章。选取相关文献查找全文,纳入57篇,其中有关T淋巴细胞与移植后免疫状态研究背景的文献9篇,有关调节性T细胞在移植免疫中的作用10篇,有关T淋巴细胞与移植后免疫耐受关系的文献17篇,有关T淋巴细胞与移植后免疫耐受研究前景的文献21篇。结果与结论：T淋巴细胞是调节机体免疫应答一类重要的免疫细胞。接受同种异体肝移植后,受体发生免疫排斥还是免疫耐受与免疫系统中丁淋巴细胞的亚群及其功能密切相关。通过阻断或诱导T淋巴细胞的某些功能可以诱导宿主免疫耐受。     

海洛因依赖者HBV和HCV感染及相关知识认知情况调查

目的了解海洛因依赖者HBV、HCV感染现状及对相关知识的认知情况,以便制定对策,进行有效的预防和健康宣教。方法对2007年12月-2008年2月在药物维持治疗门诊服药的98例海洛因依赖者进行HBV、HCV检测和问卷调查,调查内容包括对吸毒危害、传染病及其防护知识的认知情况。结果98例海洛因依赖者中,感染HBV者21例,感染率21％;感染HCV者79例,感染率81％;感染者占注射吸毒人数的96％（77/80）。海洛因依赖者对吸毒危害的知晓率较高,但对传染病及其防护的认识不足。结论海洛因依赖者HBV、HCV感染率高,传染病知识缺乏,防护意识薄弱,需加强毒品和传染病防护知识的宣传和教育。     

肾癌各期患者调节性T细胞的表达

目的检测并比较Ⅰ期~Ⅲ期肾癌患者体内调节性T细胞(Tregs)的分布变化并探索可能的趋化机制。方法收集30例肾癌患者血液及组织标本,其中Ⅰ期~Ⅲ期患者各10例;另选取同期6例非肾癌患者标本予以对照。应用流式细胞术及免疫组化检测外周血及组织的CD4+CD25+Foxp3+Tregs表达;应用RealtimePCR检测组织中CCR4/CCL22转录水平。结果肾癌患者外周血CD25+Foxp3+Tregs和肾癌组织中Foxp3经定量统计分析显示,Ⅰ期~Ⅲ期均高于非肿瘤对照组,差异均有统计学意义(t分别=5.33、8.30、6.14、9.85、8.29、20.14,P均<0.05),且随肿瘤分期增高,Tregs和Foxp3水平亦呈相应上升趋势,差异均有统计学意义(t分别=2.24、8.29、2.45、5.51,P均<0.05)。实时定量PCR结果,显示肾癌组织局部趋化因子CCR4及其配体CCL22转录水平较非肿瘤对照组明显增加,差异均有统计学意义(t分别=5.68、8.97、6.68、12.98、13.28、11.98,P均<0.05)。结论肾癌患者外周血及肿瘤组织中Tregs含量较非肿瘤患者升高,从而抑制机体抗肿瘤免疫功能。肿瘤组织高表达CCL22,从而趋化Tregs至肿瘤组织内。     

Induced and natural regulatory T cells in human cancer

Introduction: Evidence suggests that FOXP3⁺CD25^highCD4⁺ regulatory T cells (Treg) which accumulate in cancer may have beneficial or unfavorable effects on prognosis. The presence in tumor-associated inflammatory infiltrates of two subsets of Treg with distinct phenotypic and functional profiles might explain these conflicting observations.

Areas covered: Human inducible (i) Treg arising by tumor-driven conversion of conventional CD4⁺ T cells are highly suppressive, therapy-resistant Treg which down-regulate anti-tumor immune responses, promoting tumor growth. Natural (n) Treg, normally responsible for maintaining peripheral tolerance, control cancer-associated inflammation, which favors tumor progression. This division of labor between nTreg and iTreg is not absolute, and overlap may be common. Nevertheless, iTreg play a critical and major role in cancer and cancer therapy. The tumor microenvironment determines the type, frequency and suppression levels of accumulating Treg.

Expert opinion: In cancer, a selective removal or silencing of iTreg and not of nTreg should be a therapeutic goal. However, the implementation of this challenging strategy requires further studies of cellular and molecular crosstalk among immune cells in the tumor microenvironment.     

T regulatory cells in cancer: recent advances and therapeutic potential

Importance of the field: The active suppression of immune responses against tumor is a major barrier to the likely success of cancer immunotherapy. There is now compelling evidence implicating T regulatory cells (Tregs) as being key players driving immune suppression. Elevated frequencies of Tregs within the peripheral circulation and tumor microenvironment of cancer patients correlate with poor prognosis and reduced survival. Understanding the mechanism of Treg elevation is critical for the development of new approaches aiming to modulate the frequency and function of Tregs to enhance the efficacy of cancer immune-based therapies.

Areas covered in this review: This review focuses on current knowledge concerning Tregs in cancer and discusses putative mechanisms which underlie the expansion of Tregs in cancer patients. Additionally, we review current strategies to deplete/suppress Treg activity, the limitations of these strategies and future perspective for improving their efficacy.

What the reader will gain: An insight of the current aspects concerning Treg subsets in cancer and an overview of recent advances in the identification of Treg-specific markers, in addition to the potential strategies to target Tregs for enhancing antitumor immunity.

Take home message: Mechanisms by which Treg functions modulate the immune response to tumors are becoming further understood. However, specific markers to tumor-specific/induced Tregs are yet to be clearly identified, which is a major limitation in optimizing strategies to specifically target Tregs in cancer. Despite this, strategies aimed at modulating Tregs in patients are providing some early encouraging results supporting the overall concept and indicating that further studies are clearly warranted.     

2型糖尿病患者HBV和HCV感染率的临床调查及分析

目的 了解2型糖尿病(T2DM)人群丙型肝炎病毒(HCV)和乙型肝炎病毒(HBV)的感染率,以及病程延长、胰岛素应用是否会增加肝炎病毒传播的风险.方法 采用横断面的研究比较188名住院T2DM患者和253名非住院T2DM患者HCV和HBV感染率的差异,并采用Logistic回归分析病程及注射胰岛素足否为肝炎病毒传播的危险因素.结果 住院T2DM患者HBsAg和抗-HCV的阳性率均高于流调的T2DM患者(12.2%vs.9.6%;2.7%vs.1.6%),但是差异没有统计学意义(P>0.05).结论 病程和胰岛素应用不增加HBV和HCV的传播风险.     

调节性T细胞在胰腺癌免疫治疗中的作用机制与应用策略

免疫治疗在胰腺癌的临床试验中疗效欠佳,主要原因在于胰腺癌具有高度免疫抑制的肿瘤微环境（tumor microenvironment, TME）。调节性T细胞（regulatory T cells, Tregs）是一类控制自身免疫反应的T细胞亚群,也是免疫抑制性TME的主要组成成分之一。Tregs能调控机体免疫反应强度,抑制效应T细胞的功能和活性进而诱导免疫耐受,维持免疫应答稳态。在胰腺癌TME中,Tregs通过抑制机体免疫反应从而介导肿瘤细胞发生免疫逃逸,影响患者的疗效与预后。本综述总结Tregs在胰腺癌免疫微环境中的作用机制及在胰腺癌中的临床意义,以期为胰腺癌免疫治疗提供更多的新思路。     

25例肾病综合征患儿调节性T细胞水平变化及意义

目的：观察肾病综合征（NS）患儿外周血中调节性T细胞（Treg）、淋巴细胞各亚群的变化,探讨其在疾病发生和发展中的作用。方法选取20例健康儿童作为对照组,25例患儿作为肾病综合征组。采用流式细胞术对两组儿童进行外周血Treg、淋巴细胞各亚群检测。结果与正常对照组比较,NS组的外周血CD4^＋CD25^＋CD127^-／low Treg细胞、CD3^＋CD4^＋辅助性T细胞、CD19^＋B细胞表达均明显降低（P＜0．05）;而CD3^＋CD8^＋抑制性T 细胞表达明显升高（P＜0．05）;肾病综合征组患儿的 CD16^＋CD56^＋NK细胞表达降低,但与对照组相比无统计学差异（P＞0．05）。结论淋巴细胞免疫功能的紊乱,特别是Treg的表达及其功能的改变,参与了肾病综合征的发病,其检测可有助于肾病综合征的诊治。     

Role of regulatory T cells in tolerance to coagulation factors

Summary.  The immune response to coagulation factors VIII or IX, in particular formation of inhibitory antibodies, complicates treatment of hemophilia. Therefore, a number of recent studies in animal models have explored novel approaches toward induction of immune tolerance in protein or gene replacement therapy. Strong evidence has emerged that regulatory T cells (Treg) are an important component of the mechanism by which tolerance is maintained and inhibitor formation, a T help dependent response, is prevented. Limited data in patients also support this concept. In particular, CD4⁺ CD25⁺ FoxP3⁺ Treg, whether naturally occurring or induced, have been invoked in suppression of antibody and of cytotoxic T lymphocyte responses to the therapeutic clotting factor. This review summarizes the data on this emerging concept of Treg-mediated regulation of the immune response in treatment of hemophilia, strategies and mechanisms of Treg induction and function, and the implications for development of immune tolerance protocols.     

外周血调节性T细胞检测在再生障碍性贫血诊断中的价值

目的 分析外周血调节性T细胞检测在再生障碍性贫血(再障)诊断中的价值.方法 选择2018年4月至2020年3月于我院就诊的31再障患儿为研究对象,根据再障类型将其分成非重型再障组(21例)和重型再障组(10例);另选20例健康儿童为对照组.比较三组的外周血调节性T细胞水平、Foxp3 mRNA表达水平及TGF-β1水平...     

强直性脊柱炎活动期患者调节性T细胞表达及与其它指标相关性的研究

目的探讨CD4＋CD25＋CDl27low/-调节性T细胞（Treg）在强直性脊柱炎（AS）活动期患者发病中的作用机制及其与C-反应蛋白（CRP）、血沉（ESR）的相关性。方法采用流式细胞术分别检测39例AS活动期患者和20例健康对照者外周血CD4＋CD25＋CDl27low/-调节性T细胞占CD4＋T细胞比例,同时分别检测两组C反应蛋白（CRP）、血沉（ESR）的表达水平,并分析AS活动期患者CD4＋CD25＋CDl27low/-调节性T细胞与CRP、ESR的相关性。结果AS活动组外周血CI）4＋CD25＋CDl27low/-Treg与对照组比较明显降低,具有统计学意义（P〈0．01）。AS活动组CRP、ESR与对照组比较均明显升高（P〉0．05）,具有统计学意义（P〈0．01）。但AS活动期患者CD4＋CD25＋CD127low/-Treg表达率与CRP、ESR均未见明显相关性。结论AS活动期患者CD4＋CD25＋CDl27low/-Freg细胞数量的减少可能使免疫活性细胞逃避机体对它们的免疫调节,导致体内诱导免疫耐受机能不足,从而促进AS的发生发展。进行CD4＋CD25＋CDl27low/-Treg的检测有助于评估AS活动期患者免疫状态,判断疾病进展,但其与CRP、ESR的相关性尚有待于进一步的研究。     

CD4+CD25+调控T细胞及其在移植耐受中的作用

CD4^ CD25^ 调控T细胞是一群表型和功能特异的T细胞亚群,能抑制CD4^ CD25^-和CD8^ T细胞的活化和增殖,以及IL-2和IFN-γ的产生,在移植免疫耐受中发挥着重要的作用,其免疫调控机理仍不明确。CD4^ CD25^ 在体外能有效地被分离、活化和扩增,并能保持其免疫调控能力,其活化后的免疫抑制功能是抗原非特异性的。体外活化和扩增的CD4^ CD25^ 调控T细胞有广阔的应用前景。     

Expression of CD4+CD25highCD127low/− regulatory T cells in transitional cell carcinoma patients and its significance

To evaluate the expressions of CD4⁺CD25^highCD127^low/? regulatory T cells (Tregs) in peripheral blood from patients with transitional cell carcinoma (TCC) in urinary system, we investigated the proportion of Treg population in CD4⁺ T from 93 patients with TCC, 38 with benign urinary diseases, and 37 healthy subjects by using flow cytometric analysis and analyzing different clinicopathologic characteristics and the changes before and after operation. We found that the proportion of Treg in peripheral blood from patients with TCC was significantly increased as compared with the othertwo groups. There was a strong correlation between the proportion of Treg and tumor recurrence, quantity, lymph node metastasis (P<0.01), as well as pathological stage; no correlation was found between the proportion of Treg and clinical TNM stage (P>0.05). The proportion of Treg was also different before and after operation (P<0.05). This suggest that CD4⁺CD25⁺CD127^low/? regulatory T cells may be responsible for immune suppression in TCC patients. The resection of tumor can decrease the proportion of Treg in peripheral blood. J. Clin. Lab. Anal. 23:197–201, 2009. © 2009 Wiley‐Liss, Inc.     

卵巢癌患者外周血CD4~+ CD25~+调节性T细胞的检测及其临床意义

目的探讨卵巢癌患者CD4+CD25+调节性T细胞的比例变化及其可能的机制。方法利用流式细胞仪检测20例卵巢癌患者外周血淋巴细胞(peripheral blood lymphocytes,PBLs)、肿瘤浸润淋巴细胞(tumor infiltrating lymphocytes,TILs)及肿瘤相关淋巴细胞(tumor associated lymphocytes,TALs)中CD4+CD25+调节性T细胞(CD4+CD25+Tcells,Tregs)所占的比例。10例健康人外周血PBLs中Tregs所占的比例。同时检测卵巢癌患者CD4+外周血淋巴细胞中CD69+细胞的比例。健康人PBLs在含有卵巢癌细胞株SKOV3培养上清的RPMI1640培养液(有或没有血清植物血凝素)中培养72小时后,检测Tregs所占的比例。结果卵巢癌患者外周血淋巴细胞中CD4+CD25+调节性T细胞所占比例与健康人相比明显增加.卵巢癌患者外周血肿瘤浸润淋巴细胞中CD4+CD25+调节性T细胞所占比例高于在外周血淋巴细胞和肿瘤相关淋巴细胞中的比例,但是没有统计学意义。卵巢癌患者CD4+外周血淋巴细胞中无CD69表达。结论卵巢癌患者外周血淋巴细胞中、肿瘤浸润淋巴细胞及肿瘤相关淋巴细胞中CD4+CD25+调节性T细胞所占的比例增加,这可能与卵巢癌细胞分泌的可溶性分子上调有关。     

哮喘患者外周血CD4^＋CD25^＋调节性T细胞的测定及临床意义

目的探讨CD4^＋CD25^＋调节性T细胞在哮喘患者外周血的变化及意义。方法采用流式细胞术检测60例哮喘患者和40例健康对照者外周血中CD4^＋CD25^＋调节性T细胞的表达量,同时测定20例急性发作期哮喘患者的肺功能。结果哮喘患者外周血CD4^＋CD25^＋调节性T细胞占CD4^＋T细胞的百分比明显低于健康对照组,差异有统计学意义（P〈0．01）;急性发作期哮喘患者外周血CD4^＋CD25^＋调节性T细胞明显低于非急性发作期患者,差异也有统计学意义（P〈0．01）。结论CD4^＋CD25^＋调节性T细胞参与了哮喘的发生。     

强直性脊柱炎患者外周血中调节性B细胞亚型的表达及其与疾病活动度的关系

目的探讨强直性脊柱炎(ankylosing spondylitis,AS)中调节性B细胞(regulatory B cells,Breg)的水平及与疾病活动度间的关系。方法选取确诊AS患者38例,按BASDAI评分分为活动期21例和非活动期17例,同时选取30例健康人对照者,AS患者与对照组间一般资料差异无统计学意义。ASDAS-CRP和BASDAI评分作为疾病活动度评价指标。用流式细胞术检测AS患者外周血CD19+CD24hiCD38hiBreg、CD19+CD24hiCD27+Breg、CD4+CD25highTreg及CD3+IL-17+CD8-TH17比例,荧光定量PCR检测RORγt和Foxp3 mRNA表达水平。结果 AS患者CD19+CD24hiCD38hiBreg比例为(2.10±0.16)%,显著低于对照组(3.44±0.80)%,其中活动期患者[(1.88±0.66)%]低于非活动期患者[(2.36±0.57)%],均低于对照组,差异均有统计学意义。AS患者CD19+CD24hiCD38hiBreg与Foxp3 mRNA成显著正相关性(r=0.369,P0.05),与TH17、RORγt mRNA、BASDAI评分及ASDAS-CRP负相关(r分别为-0.338、-0.661、-0.411、-0.714,P均0.05),而与Treg无相关性(r=-0.006,P0.05)。而AS患者中CD19+CD24hiCD27+Breg亚群比例与对照组间差异则无统计学意义,但活动期患者比例有所降低,与非活动期患者及对照组比较,差异有统计学意义。AS患者中CD19+CD24hiCD27+Breg亚群比例与Foxp3 mRNA正相关(r=0.344,P0.05),与ASDAS-CRP负相关(r=-0.383,P0.05),但与TH17、Treg、RORγt mRNA及BASDAI评分均无显著相关性。结论 AS患者中存在异常的Breg表型主要为CD19+CD24hiCD38hiBreg,其在AS患者中显著降低,并与疾病活动度密切相关,且与RORγt和Foxp3 mRNA水平及TH17数量存在一定的关联。     

慢性乙型肝炎患者外周血CD4^＋CD25^＋调节性T细胞的检测与意义

目的：探讨慢性乙型肝炎患者外周血CD4^＋CD25＋调节性T细胞（Treg）频率的变化及其意义。方法：分离20例慢性乙型肝炎（CHB）患者和10例健康者的外周血单个核细胞,以CD4、CD25、CD127单克隆抗体标记细胞后以流式细胞仪检测并分析Treg频率。采用实时荧光定量RT—PCR检测血清HBVDNA载量。结果：CHB组的Treg频率高于健康对照组（P〈0．05）,HBeAg阳性CHB组Treg频率高于HBeAg阴性CHB组（P〈0．01）,乙型肝炎肝硬化组Treg频率高于无肝硬化CHB组（P＜0．01）;CHB患者的Treg频率与HBVDNA载量成直线正相关（r=0．87,P＜0．01）。结论：慢性乙型肝炎患者外周血Treg频率明显升高,且与病毒复制和肝脏慢性病变程度有关。