1、Tfh(滤泡性辅助性 T 细胞)滤泡辅助性 T 细胞是近年来在研究中发现的一种比较特殊的辅助性 T 细胞（Th 细胞） 。有明显区别于其他 Th 细胞亚群的特征性标志，但是其中最主要的标志物是 CXCR5+。 Tfh 细胞是最近几年研究发现的一类细胞。 Tfh 细胞 通过基因调控或者分泌细胞因子来对细胞进行调控，间接调控体液免疫来影响人体。 Tfh 细胞对许多疾病都有影响，几乎每一种自身免疫病都与 Tfh 有着联系。 【王俊文,官杰.Tfh 细胞与临床疾病的研究进展.2014,35(15)】Tfh 细胞主要的功能 是通过产生 IL-21，辅助 B 细胞产生抗体而间接参与适应免疫应答，从而对机体
2、起到保护作用。Tfh 细胞的分化2.1 Tfh 细胞分化是不同于 Th1、Th2 和 Th17 的独立的分化过程。2.2 IL-21 是 Tfh 细胞分化所必需的细胞因子。IL-21 在淋巴细胞活化、维持、分化及体液免疫中发挥着十分重要的作用，它能促进 IFN-1的产生、增强 CD8+T 细胞和 NK 细胞的细胞毒作用。Tfh 辅助 B 细胞的 作用机制Tfh 对 B 细胞介导的体液免疫应答的作用是通过其分泌或表达的多种分子实现的。IL2l不但在 Tfh 分化、发育过程中发挥重要作用，在对 Tfh 对 B 细胞的促进作用方面也起到了重要作用。研究表明，IL-21 可以诱导人类扁桃体、脾脏、派氏
3、集合区等部位分离出来的所有成熟 B 细胞产生大量的 IgM、IgG 和 IgA，其机制在于 IL-21 诱导 B 细胞发生类型转换重组、浆细胞分化及 Ig 的分泌 013。ICOS 是 CD28 家族中的一员，其受体(ICOS ligand， ICOSL)主要表达于包括 B 细胞在内的 APC。ICOS 调节 B 细胞的功能主要是通过促进 Tfh 产生多种细胞因子实现的，B 细胞上高表达的 ICOSL 与 Tfh 上的 ICOS 结合后可以诱导 Bcl-6 的表达，从而促进 Tfh 的分化、增殖，使 Tfh 产生更多的 IL-21、IL-4、IL 一10 等，增强 B 细胞的免疫应答反应。【周
4、建伟,孔翠.滤泡辅助性 T 细胞与相关疾病研究进展.2012,9(5)】Tfh 的功能T 细胞辅助 B 细胞产生抗体是胸腺依赖性体液免疫反应的基本方式，也是生发中心的产生、记忆 B 细胞和浆细胞生成的基本要素。国外多项研究显示：Tfh 在 B 细胞分化过程中起主要作用，它促使 GC 中具有抗原高亲和力，缺乏自身反应性的 B 细胞分化为高亲和力的浆细胞和对感染起长期保护作用的记忆性 B 细胞，并且在促进 GC 的形成和免疫球蛋白类别转换，维持长时间的体液免疫应答等方面也发挥关键作用，认为 Tfh 是抗体免疫应答真正的辅助者.【辛宁，张勇，沈霞滤.泡辅助性 T 细胞与自身免疫性疾病的研究进展 20
5、13，1（1） 】3.1 Tfh 与自身免疫病(类风湿性关节炎、系统性红斑狼疮、原发性干燥综合征、儿童皮肌炎、重症肌无力)在抗体介导的自身免疫病中，发挥着正向调控的作用，为自身反应性 B 细胞提供辅助信号，促使疾病的发生。3.2 Tfh 细胞与艾滋病HIV 病毒主要侵犯人体的 CD4+T 细胞导致机体的免疫力下降。 Tfh 是主要的抗病毒细胞，参与了机体对病毒的杀伤和清除，研究表明 Tfh 细胞的生发中心 HIV（HIV-1）复制更活跃。Tfh 细胞 AIDS 患者或隐性感染者体内都是明显升高的，患者中提取出来的 Tfh 细胞的Bcl-6 的表达也是升高的。33 Tfh 细胞与肝病（自身免疫性
6、肝炎、HBV、HCV）Tfh 细胞稳定表达 CXCR5，使 Tth 和 B 细胞共同定位于淋巴滤泡 ， 并相互作用活化 B细胞 ，促进生发中心的形成。T f h 细胞及其相关分子 ( ICO S 、I L - 2 1 、 C X C R 5 、 P D.1 等) 可能参与肝脏疾病的免疫应答。3.4 与肿瘤生发中心(Germinal center，GC)：激活的 B 细胞因为发生了 B-FDC 间的相互作用，一些激活后的 B 细胞分化为产生 IgM 的浆细胞(Plasma cell)，而大部分激活的 B 细胞则返回到初级淋巴滤泡，并在该处大量增殖和分化，形成一种特殊的结构称为生发中心。因此,Tf
7、h 细胞对于 B 细胞完成的体液免疫功能发挥重要的作用。滤泡树突状细胞 (follicle dendritic cell，FDC)FDC：位于淋巴结及脾脏滤泡中的树突状细胞。具有长的突起，可与 B 细胞紧密接触，表达 Fc 受体，但不介导内吞作用，从而使 抗原-抗体复合物在其树突上形成免疫复合物包被小体而长期保存，在激活 B 细胞中起重要作用，可能参与 B 细胞的免疫记忆应答。Tfh 细胞的来源有三种模型：第一种认为 Tfh 细胞与 Th 细胞来自于不同的 CD+T 细胞，CD+T 细胞膜上的 TCR 与抗原亲和力最强的细胞分化为 Tfh 细胞，即前抗原模型；第二种认为 Tfh 细胞与 Th
8、细胞来源一样都来源于 Th 细胞的前体，即多向性模型；第三种认为Tfh 细胞以及其他 Th 细胞的分化都依靠细胞因子，并且认为 Th1 与 Th2 细胞来源于一样CD+T 细胞前体，因为它们都可以产生 IL-4，即协调性模型 。Central Memory CD4+ T Cells Are Responsible for the Recombinant Bacillus Calmette-Guerin DELTAureC: hly Vaccines Superior Protection Against Tuberculosis. 中央内存 CD4 + T 细胞负责重组卡介苗DELTAureC
9、:他疫苗 AgainstTuberculosis 卓越的保护。Central Memory CD4+ T Cells Are Responsible for the Recombinant Bacillus Calmette-Guerin DELTAureC: hly Vaccines Superior Protection AgainstTuberculosis.Vogelzang, Alexis 1; Perdomo, Carolina 1; Zedler, Ulrike 1; Kuhlmann, Stefanie 1; Hurwitz, Robert 2; Gengenbacher, M
10、artin 1,a; Kaufmann, Stefan H. E. 1JournalsOvid Full TextJournal of Infectious Diseases. 210(12):1928-1937, December 15, 2014.Article MAJOR ARTICLES AND BRIEF REPORTSAN: 01451459-201412150-00011.View AbstractAB Bacillus Calmette-Guerin (BCG) has been used for vaccination against tuberculosis for nea
11、rly a century. Here, we analyze immunity induced by a live tuberculosis vaccine candidate, recombinant BCG DELTAureC:hly vaccine (rBCG), with proven preclinical and clinical safety and immunogenicity. We pursue in-depth analysis of the endogenous mycobacteria-specific CD4+ T-cell population, compari
12、ng the more efficacious rBCG with canonical BCG to determine which T-cell memory responses are prerequisites for superior protection against tuberculosis. rBCG induced higher numbers and proportions of antigen-specific memory CD4+ T cells than BCG, with a CXCR5+CCR7+ phenotype and low expression of
13、the effector transcription factors T-bet and Bcl-6. We found that the superior protection of rBCG, compared with BCG, correlated with higher proportions and numbers of these central memory T cells and of T follicular helper cells associated with specific antibody responses. Adoptive transfer of myco
14、bacteria-specific central memory T cells validated their critical role in protection against pulmonary tuberculosis. (C) Copyright Oxford University Press 2014.卡介苗(BCG)已被用于结核病疫苗近一个世纪。在这里,我们分析现场结核病候选疫苗引起的免疫力,重组BCGDELTAureC:他疫苗(rBCG),证明临床前和临床安全性和免疫原性。我们追求深度分析内生mycobacteria-specific CD4 + t 细胞数量,对比更有效的
15、与规范 BCG rBCG 确定哪些记忆 t 细胞反应的先决条件优越的预防结核病。rBCG 诱导更高的特异性记忆数字和比例比 BCG CD4 + T 细胞,与 CXCR5 +其+表型和低表达的效应器转录因子 T-bet Bcl-6。我们发现 rBCG 优越的保护,与波士顿咨询公司相比,与更高的比例和数量的这些中央记忆 T 细胞和卵泡辅助细胞与特定的抗体应答反应相关联。过继转移 mycobacteria-specific 中央记忆 T 细胞验证防止肺结核的重要作用。 【与是否打疫苗联系起来】Decreased Frequencies of Circulating CD4+ TFH Cells As
16、sociated with Diminished Plasma IL-21 in Active Pulmonary Tuberculosis低频的 CD4 + Tfh 细胞与活动性肺结核中血浆 IL-21 减少的关联性研究AbstractBackground: Tfh cells represent a distinct subset of CD4+ T cells and are important in immunity to infections. Although they have been shown to play a role in experimental models of
17、 tuberculosis infection,their role in human tuberculosis remains unexplored. 背景: Tfh 细胞代表 CD4 + T 细胞不同子集，以及和免疫感染的重要性。虽然在肺结核感染中，他们已被证明在实验模型中发挥作用的,但他们的角色在人类结核病仍然是未知的。Method: To determine the distribution of circulating Tfh cells in human TB, we measured the frequencies of Tfh cells ex vivo （体外培养）and f
18、ollowing TB - antigen or polyclonal stimulation in pulmonary TB (PTB; n = 30) and latent TB (LTB; n = 20) individuals, using the markers CXCR5, PD-1 and ICOS.方法:确定 Tfh 细胞在人类结核病的分布,测量了 Tfh 细胞体外培养的频率，以及结核病抗原或多克隆刺激后的肺结核(PTB;n = 30)和潜在的结核病(LTB;n = 20),使用CXCR5、 PD-1、 ICOS 进行标记。Results: We found that both
19、 ex vivo and TBantigen induced frequencies of Tfh cell subsets was significantly lower in PTB compared to LTB individuals. Similarly, antigen induced frequencies of Tfh cells expressing IL-21 was also significantly lower in PTB individuals and this was reflected in diminished circulating levels of I
20、L-21 and IFNc. This was not accompanied by diminished frequencies of activated or memory B cell subsets. Finally, the diminution in frequency of Tfh cells in PTB individuals was dependent on IL-10, CTLA-4 and PD-L1 in vitro. 我们发现体外培养和人类的肺结核病中：与人类感染 LTB 相比， 抗原诱导的 Tfh 细胞频率，显著低于PTB。同样,PTB 中：抗原诱导的 Tfh 细
21、胞在表达 IL-21 的频率也显著降低,这反映了 Tfh 细胞在表达 IL-21和 IFNc 水平均有所降低。因此，要了解 PTB 中 Tfh 细胞的降低频率，依赖于体外培养中 IL-10, CTLA-4和 PD-L1 的表达。？Conclusions:Thus, PTB is characterized by a diminution in the frequency of Tfh cell subsets。结论： PTB 有一个 Tfh 细胞子集中的发生频率降低子的特点IntroductionExposure to Mycobacterium tuberculosis(Mtb) can r
22、esult in a variety of outcomes, including the absence of any clinical or laboratory evidence of infection, latent infection without active disease, active pulmonary disease or active extra-pulmonary disease 1. 暴露在结核分枝杆菌(Mtb)可以导致不同的结果,包括没有任何临床或实验室感染的证据,没有活动性疾病潜伏性感染,活动性肺结核疾病或活跃的肺外疾病 Although 2 billion
23、 people worldwide are infected with Mtb, only 510% of these individuals develop active disease, and the mechanisms by which most individuals resist development of active disease are still not clear 1. 尽管全球 20 亿人结核分枝杆菌感染,只有 5 - 10%的这些个体发展为活动性疾病,大多数人抵抗的机制发展活动性疾病仍然不清楚 However, while by definition,indiv
24、iduals developing active TB exhibit a compromise in their ability to mount a protective immune response against MTB, the exact nature of this protective immune response needs to be determined. A wide range of specific and non-specific host immune responses are thought to contribute to the differenti
25、al outcomes of infection and disease, although there is no unifying hypothesis to explain the differences seen. 然而,尽管根据定义,个人发展中活动性结核病展览妥协他们的能力对 MTB 保护性免疫反应 ,这种保护性免疫反应的确切性质需要确定。广泛的特异性和非特异性宿主免疫反应被认为有助于鉴别感染和疾病的结果,虽然没有统一的假说来解释的差异。Circulating Tfh cells are peripheral counterparts of conventional Tfh cell
26、s, that are predominantly located in secondary lymphoid tissues. Conventional Tfh cells are CD4+T cells that express the chemokine receptor CXCR5, co-stimulatory molecules such as ICOS, PD-1, the transcription factor Bcl-6 and the cytokine, IL-21. Circulating Tfh cells similarly express CXCR5, PD-1,
27、 ICOS but do not express Bcl-6. 循环 Tfh 细胞是传统 Tfh 细胞末梢区域的对应物， 主要位于次级淋巴组织。传统 Tfh 细胞即 CD4 + T 细胞，是表达趋化因子受体： CXCR5, 协同刺激分子，如ICOS、PD-1、转录因子 Bcl-6 和细胞因子 IL-21。循环 Tfh 细胞同样表达 CXCR5,PD-1,ICOS,但不表达Bcl-6。In addition,although some studies have defined circulating human Tfh cells as all CD4+ T cells expressing C
28、XCR5 + only, other studies have suggested that CD4 + CXCR5 + T cells can be further divided into those that are PD-1+, ICOS+, and/or IL-21+. It is unclear whether expression of PD1, ICOS or IL-21 defines different subpopulations of Tfh cells. Nevertheless, these cells are known to promote the differ
29、entiation of memory (but not naive) B cells to plasma cells. Dysregulated 异常调节 activity of conventional and circulating Tfh cells have been found to contribute to autoimmune or immune-deficiency states in several models of human disease. 此外,尽管一些研究人类循环 Tfh 细胞,把它定义为所有的 CD4 + T 细胞仅表达 CXCR5 +,而其他的研究表明,C
30、D4 +、CXCR5 + T 细胞可以进一步分为 PD-1 +,ICOS+,和/或 IL-21 +。目前尚不清楚 Tfh 细胞中不同的亚种：PD1、ICOS 或 IL-21 的表达。然而,这些细胞会促进不同的记忆 B 细胞分化为血浆细胞。有研究发现，在一些人类疾病的模型中，传统活性的异常调节和循环 Tfh 细胞特异表达基因会导致自身免疫或免疫缺陷状态。In addition, circulating Tfh cells have been shown to be biomarkers of effective humoral immunity in vaccination and infect
31、ious disease studies. Finally, conventional Tfh(CD4+ CCR5+) cells have been shown to mediate protective immunity against tuberculosis. Thus, while the requirement for Tfh cells in animal models of TB infection is well-defined, the role of circulating Tfh cells in human TB infection and disease has n
32、ot been explored. 此外,循环 Tfh 细胞已被证实是有效的体液免疫和传染性疾病研究的疫苗接种生物标记物。因此,传统 Tfh(CD4 + CCR5 +)细胞已被证明对肺结核11调解保护性免疫。因此,虽然要求 Tfh 细胞在动物模型的结核病感染有明确定义，而对人类的结核感染和对疾病的作用尚不清楚。To study the distribution of Tfh cells in TB infections, we examined Mtb antigen-specific induction Tfh cells subsets (defined as CD4+，CXCR5+，PD
33、-1+，ICOS2 or CD4+，CXCR5+ ，PD-，ICOS+ or CD4+，CXCR5+，PD-1+，ICOS+) in PTB and LTB individuals in an area highly endemic for tuberculosis. We observed that active PTB was characterized by diminished frequencies of Tfh cells ex vivo and in response to TB antigens and by diminished frequencies Tfh cells p
34、roducing IL-21, a finding that was reflected in circulating plasma levels of IL-21. 本研究是在结核病感染者中了解 Tfh 细胞的分布情况,我们检测了 Mtb 特异性诱导 Tfh 细胞子集在 PTB和 LTB 中，一个区域高度流行的肺结核。我们观察到体外培养中 PTB Tfh 细胞的活性特点是频率降低。针对结核抗原和减少 Tfh 细胞频率产生 IL-21,这一发现是反映在循环等离子 IL-21 水平。 IL-10,CTLA-4 and PD-L1 each appear to play a role in the
35、 Tfh homestasis as well. Our data therefore suggest that central defects in Tfh subset differentiation and/or function is a feature of active pulmonary tuberculous disease. IL- 10,CTLA-4 和 PD-L1 似乎扮演一个角色在 Tfh homestasis。我们的数据表明,中央缺陷 Tfh 子集分化和 /或功能是活动性肺结核结核性疾病的一个特色。Study populationWe studied a group
36、of 50 individuals; 30 with pulmonary TB(PTB) and 20 individuals with latent TB (LTB). Among the 30 individuals with PTB, 19 of these were also used for antibody blocking studies. Individuals with PTB were diagnosed sputum smear and culture positivity. Individuals with LTB were diagnosed on the basis
37、 of being positive in the Quantiferon-TB Gold in Tube (Cellestis) assay but having an absence of pulmonary symptoms concurrent with a normal chest radiograph. All subjects had been bacillus Calmette-Guerin (BCG) vaccinated at birth. All the individuals were HIV negative and blood was collected prior
38、 to commencement of anti-TB treatment. 我们研究了一群 50 个人,30 与肺结核(PTB)和 20 个人和潜在的结核病(LTB)。在 PTB 的 30 个人,其中 19 也用于抗体阻断研究。PTB 的人被诊断为痰涂片和培养积极性。个人 LTB 被诊断的基础上,积极在 Quantiferon-TB 黄金管(Cellestis)测定但缺乏肺并发症状有正常胸部 x 光照片。所有科目都卡介苗(BCG)出生时接种疫苗。所有的个人都是消极和 HIV 病毒的血液收集毕业典礼前抗结核治疗。Antigens 抗原Mycobacterial antigens - PPD (
39、Statens Serum Institute,Copenhagen, Denmark), ESAT-6 and CFP10 (both from NIAIDTB antigen repository at BEI resources) were used as antigenic stimuli, and anti-CD3 antibody was used as positive control. Final concentrations were 10mg/ml for PPD, ESAT-6 and CFP-10 and 5mg/ml for anti-CD3. For antibod
40、y ELISA, PPD and MTB whole cell lysate (WCL) were used as the antigens. 分枝杆菌抗原产后抑郁症(史坦顿血清研究所,哥本哈根,丹麦),ESAT-6 和 CFP-10(从 NIAIDTB 抗原库贝资源) 作为抗原刺激,和 anti-CD3 抗体被用来作为积极的控制。最后 10 毫克/毫升浓度对产后抑郁症,ESAT-6 anti-CD3 CFP-10 和 5 毫克/毫升。结核分枝杆菌抗体ELISA、产后抑郁症和整个细胞溶解产物( 水控制法)作为抗原。In vitro culture 体外培养Intracellular cytok
41、ine staining 细胞内因子染色(ELISA)DiscussionInfection with Mtb can lead to various outcomes that range from active or chronic pulmonary disease, extra-pulmonary TB and latent TB, that occurs when the initial infection is controlled but not completely eliminated. While a number of host immune mechanisms hav
42、e been described to play a role in the diverging clinical manifestations of TB infection and disease, the immune mechanisms that contribute directly to disease pathogenesis are still incompletely understood. Tfh cells are a subset of CD4+ T cells that are indispensable for the generation and mainten
43、ance of humoral immunity. 结核分枝杆菌感染可以导致不同的结果,从活跃或慢性肺疾病,肺外结核病和潜伏性结核病,发生在最初的感染控制,但不能完全消除。虽然描述了一系列的宿主免疫机制发挥作用的不同临床表现的结核感染和疾病的免疫机制,有助于疾病的发病机制仍不完全清楚。Tfh 细胞 CD4 + T 细胞的一个子集,是不可或缺的生成和维护体液免疫。It has recently been demonstrated that CXCR5+ T cell accumulate within ectopic lymphoid structures associated with TB
44、granulomas in humans,non-human primates and mice. These lymphoid follicles appear to be important for proper localization of T cells in the granulomas, for the optimal activation of macrophages and for protection against TB disease. Thus, while Tfh cells located within the granulomas are clearly imp
45、ortant in the immune response to TB, the role of circulating Tfh cells in human TB infection and disease remains unexplored. 它最近被证明 CXCR5 + T 细胞内积累异位淋巴结构在人类与结核肉芽肿 ,非人类的灵长类动物和老鼠。这些淋巴滤泡似乎重要的适当的本地化的 T 细胞肉芽肿 ,最佳活化的巨噬细胞和预防结核病。因此,虽然 Tfh 细胞位于肉芽肿在结核病免疫反应,显然是重要的角色循环 Tfh 细胞在人类结核病感染和疾病仍然是未知的。The distribution o
46、f Tfh cells in TB infection and disease was studied by classifying them into 3 subsets. We first attempted to infer the function of these Tfh subsets expressing different combination of surface markers by examining their response to MTB antigens in those with LTB and those with active PTB. Our data
47、clearly reveals that both PD-1 and ICOS either separately or together mark Tfh cells with similar properties in terms of antigenic responsiveness. Tfh 细胞结核感染和疾病的分布研究了分类成三个子集。我们第一次试图推断出这些 Tfh 子集的函数表达不同的表面标记组合通过检查他们对结核分枝杆菌抗原的反应在那些 PTB LTB 和活跃。我们的数据清楚地表明,PD-1 和国际单独或一起马克 Tfh 细胞具有类似属性的抗原反应。Subsequently,t
48、he examination of frequencies of these Tfh subsets revealed asignificant reduction in the frequencies of these subsets in those with PTB. This study demonstrates for the first time, we believe, that there are decreased frequencies of Tfh cells in tuberculosis, data that are in contrast to data from
49、HIV and other viral infections where Tfh frequencies are increased. Thus, PTB appears to be selectively associated with TB - antigen specific deficiency in Tfh cells expressing either ICOS and/or PD-1. One of the major hallmarks of Tfh cells is their ability to produce a variety of cytokines most notably IL-21. Our examination of the IL-21 expressing Tfh cells in PTB reveals that the diminished frequency of Tfh cells in TB disease translated to diminished function of these cells. 随后,这些 Tfh 子集的检查频率显示乳癌的这些子集的频率在 PTB。这项研究首次表明,我们相信 ,有频率的降低 Tfh 细胞肺结核、数据与其他数据从
