白介素25与支气管哮喘关系的研究进展

白介素25(IL-25)是新近发现的IL-17家族的新成员之一,其主要由活化的Th2细胞和肥大细胞所分泌.IL-25能够促进IL-4、IL-5及IL-13分泌、增强Th2型免疫应答、导致嗜酸粒细胞的浸润,在哮喘的发病中起着重要作用.     

Th17细胞与支气管哮喘

T辅助细胞17(Th17细胞)是一种新的CD4+效应T细胞亚群,以分泌白介素(IL)-17A和IL-17F为特征.自被发现以来,Th17细胞被认为在感染时宿主防御及自身免疫所引起的组织炎症中起着重要的作用.近年来,研究者们认为Th17细胞及相关细胞因子亦参与支气管哮喘的形成.一、Th17细胞的发现在Th17细胞被命名为一个独立的T细胞亚型之前,人们已经知道IL-17是活化的CD4+ T细胞所分泌的细胞因子,并且在宿主防御及自身免疫疾病方面发挥着重要的作用.In-fante-Duarte C等[1]首次阐述了Th17细胞,即一种独立于Th1、Th2以外的T细胞亚群.他们在研究中发现,人或鼠CD4+细胞在受到莱姆病螺旋体或分枝杆菌裂解物刺激后分泌IL-17,但并不同时分泌干扰素-γ(IFN-y),且在Th1及Th2细胞体外培养中发现,并没有培养出分泌IL-17细胞群,由此分析出IL-17与Th1、Th2细胞并没有相关性.Murphy CA等[2]在鼠自身免疫疾病模型中发现,缺少IL-23对IFN--γ的分泌并没有产生影响,但是对IL-17的生成却是必需的.进一步证明,IFN-γ与IL-17来源于不同的T细胞亚群,且发现IL-23可能诱导分泌IL-17的T细胞亚群的增殖.有研究者进一步研究发现,原始CD4+T细胞在体内及体外实验中均能分化为产IL-17的T细胞亚群,且不同于Th1、Th2亚群[3].故这一类Th细胞被研究者们称为Th17细胞.     

维甲酸的免疫调节与炎症性肠病

维甲酸(retinoic acid,RA)是维生素A的衍生物,可以调节细胞的增殖、分化、成熟,是机体正常发育和各种生理活动必不可少的重要因子.RA是一种诱导分化剂,但同时也是一种免疫调节剂.一方面,可降低Th1细胞INF-γ的分泌,促进Th2细胞IL-4的分泌,平衡Th1/Th2的比率;另一方面,促进CD4+CD25+...     

Th17细胞与肝脏疾病

辅助性T细胞(Th细胞)根据产生细胞因子和生物学功能分为Th1和Th2细胞.最近研究发现了一种与Th1和Th2细胞亚群不同的活化CD4+T细胞亚群-Th17细胞.TGF-β与IL-6或IL-21的协同作用,诱导Th17细胞分化.IL-12家族的IL-23在促进IL-17分泌、增强Th17细胞效应功能方面发挥重要作用,而RORγt是其特异性转录因子.分化成熟的Th17细胞可以分泌IL-17A、IL-17F、IL-21、IL-22、IL-6、TNF-α等多种细胞因子,在介导炎性反应(防御病原菌感染)、自身免疫性疾病、肿瘤、移植排斥反应等过程中发挥重要作用.Th17细胞也为研究肝脏疾病的发病机制及防治策略提供了新思路和方向.     

菌血症患者外周血Th1、Th2细胞水平的变化研究

正常机体的CD4 T淋巴细胞根据其分泌细胞因子的不同可分别称为Th1、Th2,Th1细胞主要分泌TNF、IFN-γ、IL-2,Th2主要分泌IL-4、IL-5、IL-10等,它们发挥着不同的功能[1]。Th细胞之间的失衡与自身免疫病、过敏性疾病、肿瘤、移植排斥反应以及感染性疾病的发生发展有密切的关系。近     

己酮可可碱对充血性心力衰竭患者CD+4 Th细胞免疫调节的研究

目的 探讨己酮可可碱(PTX)对慢性充血性心力衰竭(心衰)患者外周血辅助性T淋巴细胞(Th)免疫调节的影响及其机制.方法 采用流式细胞分析法,检测 50例心衰患者和正常对照者(10名)外周血的CD 4 Th1和Th2细胞,及其分泌的细胞因子干扰素-γ(IFN-γ)和白介素10(IL-10)在PTX干预下的变化.结果 心衰对照组与正常对照组比较,分泌IFN-γ的Th1型细胞所占百分比明显增高而分泌IL-10的Th2型细胞所占百分比明显降低;PTX干预组与心衰对照组比较,分泌IFN-γ的Th1型细胞所占百分比明显降低而分泌IL-10的Th2型细胞所占百分比升高.结论 心衰患者存在CD 4 Th细胞亚群平衡偏移,而PTX可以逆转充血性心衰患者 Th1/Th2细胞的失衡,起到免疫调节的作用,从而有可能使心衰患者从中获益.     

哮喘患者树突状细胞分泌细胞因子的变化及其对Th1/Th2细胞因子的影响

目的观察过敏性哮喘(哮喘)患者外周血单个核细胞(PBMC)来源树突状细胞(DC)分泌IL-12和IL-10的情况,及其对Th1/Th2型细胞因子平衡的影响.方法分别取9例哮喘患者和14例正常人外周血PBMC来源的DC经LPS刺激使其发育为成熟DC(mDC).另取脐血初始T淋巴细胞(Th0).Th0和两组mDC共培养,通过ELISA法检测mDC分泌的IL-12和IL-10及辅助性T淋巴细胞(Th)分泌的IFN-γ和IL-4的含量.结果①哮喘组DC产生IL-12及其亚单位IL-12p40和IL-10较对照组显著降低(P＜0.01、P＜0.05).②哮喘组Th释放Th1型细胞因子IFN-γ较对照组减少(P＜0.05);Th2型细胞因子IL-4较对照组显著增多(P＜0.01).③两组IL-12和IFN-γ均呈正相关(r＝0.7581、P＜0.01,r＝0.6028、P＜0.05),IL-12和IL-4均呈负相关(r＝-0.7498、P＜0.01,r＝-0.7481、P＜0.01).④哮喘组IL-10与IFN-γ呈正相关(r＝0.6437,P＜0.05).⑤两组IL-12和IL-10均呈正相关(P均＜0.01).结论哮喘患者DC分泌IL-12和IL-10减少,导致Th0向Th2优势分化,细胞因子平衡向Th2型倾斜,合成IL-4增多和IFN-γ减少,后者是哮喘发生的重要机制之一.     

Th17细胞与自身免疫性疾病

CD4 T细胞按照分化和功能特征分为辅助性T细胞1(Th1)、Th2和调节性T细胞(Treg)。Th1细胞主要分泌γ干扰素(IFN-γ)、IL-2和肿瘤坏死因子α(TNF-α)等细胞因子,介导细胞免疫,在抗细胞内感染的细菌、病毒和寄生虫等方面发挥重要作用;Th2型细胞通过分泌IL-4、IL-5、IL-10和IL-13等     

Th1/Th2及CD4+CD25+调节性T细胞与非酒精性脂肪性肝炎

非酒精性脂肪性肝炎(NASH)是与代谢性疾病相关的一类疾病,目前其发病机制仍未完全清楚.CD4 T辅助细胞具有重要的免疫功能,优先向Th1亚群分化参与NASH的发病,Th1/Th2比值下降,促炎症细胞因子IFN-γ、TNF-α分泌增多,机制可能与胰岛素抵抗或者肝内免疫功能异常有关.CD4 CD25 调节性T细胞分泌TGF-β、IL-10抑制性细胞因子,通过抑制Th1和Th2的增殖和分化,控制疾病的进程.此文主要就Th1/Th2及CD4 CD25 调节性T细胞在非酒精性脂肪性肝炎中的研究进展作一综述.     

Th17细胞与自身免疫性疾病的关系

根据细胞的功能,经典地将CD4+T细胞分为Th1、Th2辅助细胞以及调节性T细胞3个亚群.Yh1细胞通过分泌干扰素(IFN)-γ、白细胞介素(IL)-12等细胞因子,在抗感染、抗肿瘤反应中发挥重要作用,而同时,Th1活性异常升高也是器官特异性自身免疫病发病的重要机制之一;Th2细胞则通过分泌IL-4、IL-5、IL-13等细胞因子促进机体的体液免疫应答,另一方面也参与了哮喘、系统性自身免疫病的发病过程;而调节性T细胞则在维护机体免疫平衡中发挥了重要作用~[1].然而随着研究的深入发现,一群在分化、生物学作用等方面都不同于Th1、Th2、调节性T细胞的细胞亚群,它们不表达IL-4或IFN-γ,却高水平分泌IL-17,被命名为Th17细胞~[2].现就近年来关于Th17细胞的分化发育及其在相关疾病中的作用作一综述.     

Th2 cells are less susceptible than Th1 cells to the suppressive activity of CD25+ regulatory thymocytes because of their responsiveness to different cytokines

T-cell clones generated from both CD4+CD25+ and CD8+CD25+ human thymocytes were assessed for their ability to suppress the proliferative response to allogeneic stimulation of type 1 T-helper (Th1) or type 2 T-helper (Th2) clones derived from autologous CD4+CD25- thymocytes. Both CD4+ and CD8+ T-regulatory (Treg) cells completely suppressed the proliferation of Th1 clones but exhibited significantly lower suppressive activity on the proliferation of Th2 clones. The partial suppressive effect on Th2 cells was further reduced by the addition in culture of interleukin-4 (IL-4), whereas it was increased in the presence of an anti-IL-4 monoclonal antibody (mAb). The suppressive activity on Th2 clones was also completely inhibited by the addition of IL-7, IL-9, and IL-15 but not of IL-2, whereas the suppressive effect on Th1 clones was only reverted by the addition of IL-15. Of note, Th2 clones expressed significantly higher amounts of mRNA for IL-4 receptor (IL-4R) and IL-9R alpha chains than Th1 clones, whereas the expression of mRNA for IL-2R, IL-7R, and IL-15R alpha chains was comparable. Taken together, these findings demonstrate that Th2 cells have a lower susceptibility than Th1 cells to the suppressive activity of human CD25+ regulatory thymocytes, because they are able to produce, and to respond to, growth factors distinct from IL-2, such as IL-4 and IL-9.     

Role of CD4(+) CD25(+) regulatory T cells in T helper 2 cell-mediated allergic inflammation in the airways

It has recently been shown that CD4(+) CD25(+) T cells are immunoregulatory T cells that prevent CD4(+) T cell-mediated organ-specific autoimmune diseases. To determine whether CD4(+) CD25(+) T cells downregulate Th2 cell-mediated allergic inflammation in the airways, we studied antigen-induced eosinophil recruitment in the airways in BALB/c Rag-2(-)(/-) mice transferred with CD4(+) CD25(+) T cell-depleted or unfractionated T cells from ovalbumin-specific TCR transgenic mice. Antigen-induced eosinophil recruitment into the airways was significantly decreased in the mice transferred with CD4(+) CD25(+) T cell-depleted splenocytes as compared with those transferred with unfractionated splenocytes. On the other hand, the depletion of CD4(+) CD25(+) T cells increased antigen-induced neutrophil and T cell recruitment in the airways of the mice. The depletion of CD4(+) CD25(+) T cells also decreased antigen-induced IL-4 and IL-5 production in the airways of the mice. Finally, the depletion of CD4(+) CD25(+) T cells prevented antigen-induced Th2 cell differentiation in vitro but increased the differentiation of Th1 cells. These results indicate that CD4(+) CD25(+) T cells modulate the Th1 and Th2 cell balance toward Th2 cells and thus upregulate Th2 cell-mediated allergic inflammation in the airways.     

白介素35在支气管哮喘中的作用机制

支气管哮喘（简称哮喘）是由多种细胞和细胞因子参与的慢性呼吸道炎症性疾病,发病机制可能与Th1/Th2细胞因子失衡、CD4＋CD25＋ T细胞（调节性T细胞,简称Tregs）及Th17/IL-17等异常有关。白介素35是一种新发现的细胞因子,其与Tregs及Th17/IL-17等免疫调节功能密切相关,通过多种途径参与哮喘的发病和调节,有望成为哮喘的治疗新靶点。本文对此相关研究作一综述     

CD4+CD25+ T cells alloactivated ex vivo by IL-2 or IL-4 become potent alloantigen-specific inhibitors of rejection with different phenotypes, suggesting separate pathways of activation by Th1 and Th2 responses

CD4(+)CD25(+)Foxp3(+) T cells are regulatory/suppressor cells (Tregs) that include non-antigen (Ag)-specific as well as Ag-specific Tregs. How non-Ag-specific naive CD4(+)CD25(+) Treg develop into specific Tregs is unknown. Here, we generated adaptive Tregs by culture of naive CD4(+)CD25(+)Foxp3(+) T cells with allo-Ag and either interleukin-2 (IL-2) or IL-4. Within days, IL-2 enhanced interferon-gamma receptor (Ifngammar) and Il-5 mRNA and IL-4 induced a reciprocal profile with de novo IL-5Ralpha and increased IFN-gamma mRNA expression. Both IL-2- and IL-4-alloactivated CD4(+)CD25(+) Tregs within 3 to 4 days of culture had enhanced capacity to induce tolerance to specific donor but not to third-party cardiac allografts. These hosts became tolerant as allografts functioned more than 250 days, with a physiologic ratio of less than 10% CD4(+)CD25(+)Foxp3(+) T cells in the CD4(+) population. CD4(+)CD25(+) T cells from tolerant hosts given IL-2-cultured cells had increased Il-5 and Ifngammar mRNA. Those from hosts given IL-4-cultured cells had enhanced IL-5Ralpha mRNA expression and IL-5 enhanced their proliferation to donor but not third-party allo-Ag. Thus, IL-2 and IL-4 activated allo-Ag-specific Tregs with distinct phenotypes that were retained in vivo. These findings suggested that T-helper 1 (Th1) and Th2 responses activate 2 pathways of adaptive Ag-specific Tregs that mediate tolerance. We propose they be known as T-suppressor 1 (Ts1) and Ts2 cells.     

La famille des IL-17 et la réponse allergique

Among the six members of the IL-17 family, three are clearly implicated in the regulation of the allergic response: IL-17A (also called IL-17), IL-17E (or IL-25) and IL-17F. IL-17A expresses strong homology with IL-17F and shares the same receptor. IL-17A is produced by various cells, mainly Th17 and iNKT17. IL-17A is a potent pro-inflammatory cytokine that induces the production of numerous other cytokines and chemokines and controls the recruitment and activation of neutrophils. However, in an experimental allergic asthma mouse model, IL-17A can induce either harmful or beneficial effect depending on the status of the allergic response. IL-17E, which is produced mainly by basophils and eosinophils in humans, acts mainly on Th2 cell differentiation either by polarizing naive CD4+ cells towards the Th2 pathway in an IL-4- dependent fashion, or by amplifying expansion and activation of memory Th2 cells in an IL-4-independent manner.     

Regulatory effects of 1alpha,25-dihydroxyvitamin D3 on the cytokine production of human peripheral blood lymphocytes.

We studied the possible regulatory effects of 1alpha,25-dihydroxyvitamin D3 [1alpha,25-(OH)2D3] on cytokine production and differentiation of subsets of CD4+ [T helper 1 (Th1) and Th2] and CD8+ [T cytotoxic 1 (Tc1) and Tc2] lymphocytes at the single cell level. PBMC from healthy donors were cultured with or without 1alpha,25-(OH)2D3 for up to 21 days. On days 0, 7, 14, and 21, the percentage of cytokine-producing T lymphocytes was analyzed by intracellular cytokine detection with mAb and flow cytometry. Simultaneous staining for cell surface markers allowed discrimination of CD4+ and CD8+ T cell subsets. After culture with 1alpha,25-(OH)2D3 (10(-8) mol/L), no significant effects on the proportion of interferon-gamma (IFNgamma)- or interleukin-4 (IL-4)-producing cells were detected, whereas reduced frequencies of IL-2-producing cells in the CD4+ as well as in the CD8+ population were found. An increase in the low percentage of CD4+ and CD8+ T cells producing the Th2 cytokine IL-13 was noticed. Most interestingly, IL-6-producing CD4+ and CD8+ T cells could only be detected in cultures with 1alpha,25-(OH)2D3, reaching a plateau after 14 days. The percentage of IL-6-producing T cells induced by 1alpha,25-(OH)2D3 after a given time period remained stable for at least 7 weeks. Studies of cytokine coexpression revealed that about 70% of IL-6-producing CD4+ and CD8+ cells were also positive for IL-2, but more than 90% were negative for IFNgamma, IL-4, or IL-13, respectively. This suggests that the IL-6-producing population does not match the Th1/Tc1-like (IFNgamma+) or Th2/Tc2-like (IL-4+ or IL-13+) subset. The influence of 1alpha,25-(OH)2D3 on cytokine production by lymphocytes is probably an important point of intersection between the endocrine and the immune system.     

Direct inhibition of CD40L expression can contribute to the clinical efficacy of daclizumab independently of its effects on cell division and Th1/Th2 cytokine production

Humanized anti-CD25 antibodies (eg, daclizumab) have been successfully used to treat several autoimmune diseases. Paradoxically, IL-2 blockade in mice can induce autoimmunity. An interspecies difference in the relative contribution of IL-2 to CD25(+) T regulatory cell (CD25(+)Treg) versus CD25(+) effector cell function might explain this conundrum. Consistent with this are reports that daclizumab inhibits human CD25(+) effector cell cytokine production by blocking the expression of CD40L. However, in mice, IL-4 and IL-12 regulate CD40L expression. As human Th1/Th2 cytokine production is also dependent on IL-2, daclizumab's inhibition of CD40L expression could be due to an indirect, rather than a direct, effect of IL-2. Here, we clarify the mechanisms underlying CD40L expression. In contrast to the mouse, human CD40L is regulated by CD28 signaling and IL-2, not the principal Th1/Th2-polarizing cytokines. We find that CD40L is expressed on naive and memory cells and inhibited by daclizumab independently of cell division. Collectively, our results indicate that daclizumab could inhibit CD25(+) effector T-cell function in vivo by directly blocking CD40L expression. This difference between mice and human may help explain the paradoxical effects of IL-2R blockade in the 2 species.     

T-helper cell type 2 (Th2) memory T cell-potentiating cytokine IL-25 has the potential to promote angiogenesis in asthma

IL-25 (IL-17E) is a T-helper cell type 2 (Th2) cytokine best described as a potentiator of Th2 memory responses. Reports of expression of its receptor, IL-25R, on airways structural cells suggest a wider role for IL-25 in remodeling. We hypothesized that IL-25 stimulates local angiogenesis in the asthmatic bronchial mucosa. Immunoreactive IL-25(+), IL-25R(+), and CD31(+) (endothelial) cells in sections of bronchial biopsies from asthmatics and controls were detected by immunohistochemistry. The effect of IL-25 on angiogenesis was examined using an in vitro assay. Real-time PCR was used to detect expression of IL-25R and VEGF mRNA in cultured human vascular endothelial cells (HUVEC), and a cell proliferation kit (WST-8) was used to measure the effect of IL-25 on HUVEC proliferation. Immunostaining showed that IL-25(+), IL-25R(+), and CD31(+)/IL-25R(+) cells were significantly elevated in the bronchial mucosa of asthmatics compared with controls (P < 0.003). In asthmatics, the numbers of IL-25(+) cells correlated inversely with the forced expiratory volume in 1 s (r = -0.639; P = 0.01). In vitro, HUVEC constitutively expressed IL-25R, which was up-regulated further by TNF-α. IL-25 and TNF-α also increased expression of VEGF and VEGF receptors. IL-25 increased HUVEC proliferation and the number, length, and area of microvessel structures in a concentration-dependent manner in vitro. VEGF blockade, the PI3K-specific inhibitor LY294002, and the MAPK/ERK1/2 (MEK1/2)-specific inhibitor U0126 all markedly attenuated IL-25-induced angiogenesis, and the inhibitors also reduced IL-25-induced proliferation and VEGF expression. Our findings suggest that IL-25 is elevated in asthma and contributes to angiogenesis, at least partly by increasing endothelial cell VEGF/VEGF receptor expression through PI3K/Akt and Erk/MAPK pathways.