强直性脊柱炎患者外周血CD4+CD25+调节性T细胞的研究

目的 观察强直性脊柱炎(AS)患者外周血CD4+CD25调节性T细胞(Treg)的数量、功能及肿瘤坏死因子(TNF)-a 抑制剂治疗的影响.方法 活动性AS患者25例,10例给予etanercept治疗12周,健康对照21名,分离外周血单个核细胞(PBMC),流式细胞术检测CD4+CD25high T细胞比例;实时定量聚合酶链反应检测FOXP3 mRNA表达;免疫磁珠法去除CD25+细胞,可溶性噻唑盐(WST-1)法检测T细胞增殖.结果 活动性AS组CD4+CD25high T细胞比例与对照组差异尤统计学意义,但FOXP3 mRNA表达明显低于对照组(P＜0.01),并与C反应蛋白(CRP)呈负相关(P＜0.01).两组的CD4+CD25+细胞体外均能抑制T细胞增殖(P均＜0.01). Etanercept治疗明显增加CD4+CD25highT细胞比例和FOXP3 mRNA表达(P均＜0.01),与CRP降低呈负相关(P＜0.05;P＜0.01).结论 AS患者外周血表达FOXP3的CD4+CD25+Treg细胞异常,可能参与AS发生和发展;Etanercept治疗上调Treg细胞,可能是抗TNF-α治疗的一个机制.     

Expression of CD4+ forkhead box P3 (FOXP3)+ regulatory T cells in inflammatory bowel disease

OBJECTIVE: Forkhead box P3 (FOXP3) plays an important role in the development and function of CD4⁺ regulatory T (Treg) cells. In this study the percentage of CD4⁺ FOXP3⁺ Treg cells in peripheral blood mononuclear cells (PBMC) and the frequency of Treg cells in the colonic mucosa of patients with inflammatory bowel disease (IBD) were investigated. METHODS: The percentage of CD4⁺FOXP3⁺ Treg cells in PBMC was analyzed by flow cytometry. Immunohistochemistry was used to examine the FOXP3⁺ cells in the inflamed mucosa. Real‐time polymerase chain reaction and Western blot were used to detect the expressions of FOXP3 mRNA and protein in PBMC and mucosal biopsy specimens of IBD patients, respectively. RESULTS: Together with the decrease of percentage of Treg cells in PBMC, we found that the frequency of Treg cells increased significantly in inflamed mucosa of active or inactive Crohn's disease (CD) and ulcerative colitis (UC). The expressions of FOXP3 mRNA and protein increased in inflamed mucosa when compared with those in healthy controls, especially the FOXP3 mRNA in patients with active CD or UC. Interestingly, the expression of FOXP3 protein in active UC was higher than that in active CD. CONCLUSIONS: There was a decrease of CD4⁺FOXP3⁺ Treg cells in peripheral blood and an accumulation of Treg cells in inflamed mucosa. These data suggested that the suppressive function of Treg cells may be partially inhibited and this could be an important factor in the recurrence of disease, especially in UC.     

外周血CD4~+CD25~+FOXP3~+调节性T细胞与炎症性肠病疾病活动度的关系

背景:炎症性肠病(IBD)的发病机制尚未完全阐明。调节性T细胞是一组具有免疫抑制作用的T细胞亚群,研究显示其改变与IBD的发病密切相关。目的:观察IBD患者外周血CD4~+CD25~+FOXP3~+调节性T细胞与疾病活动度的关系。方法:纳入克罗恩病(CD)和溃疡性结肠炎(UC)患者各31例,15例健康体检者作为正常对照。分别采用简化CD活动指数(CDAI)和临床活动度指数(CAI)评估CD和UC患者的疾病活动度,以流式细胞术检测外周血CD4~+CD25~+FOXP3~+调节性T细胞比例,同时检测ESR和血清CRP水平。结果:CD和UC患者外周血CD4~+CD25~+FOXP3~+调节性T细胞比例显著低于正常对照组(P0.05),并分别与简化CDAI评分和CAI评分呈负相关(P0.05),与ESR和血清CRP水平之间则无明显相关性。活动期CD和UC患者的ESR和血清CRP水平明显高于缓解期,但差异无统计学意义。ESR和CRP与疾病活动度评分之间亦无明显相关性。结论:CD4~+CD25~+FOXP3~+调节性T细胞在IBD的发生、发展中起重要作用,外周血调节性T细胞数量减少可能是IBD复发的重要因素。     

Promises and paradoxes of regulatory T cells in inflammatory bowel disease

Since their discovery two decades ago,CD4+CD25+Foxp3+ regulatory T cells(Tregs) have become the subject of intense investigation by immunologists. Unlike other T cells,which promote an immune response,Tregs actively inhibit inflammation when activated by their cognate antigen,thus raising hope that these cells could be engineered into a highly targeted,antigenspecific,immunosuppressant therapy. Although Tregs represent less than 10% of circulating CD4+T cells,they have been shown to play an essential role in preventing or limiting inflammation in a variety of animal models and human diseases. In particular,spontaneous intestinal inflammation has been shown to occur in the absence of Tregs,suggesting that there may be a Treg defect central to the pathogenesis of human inflammatory bowel disease(IBD). However,over the past decade,multiple groups have reported no qualitative or quantitative deficits in Tregs from the intestines and blood of IBD patients to explain why these cells fail to regulate inflammation in Crohn's disease and ulcerative colitis. In this review,we will discuss the history of Tregs,what is known about them in IBD,and what progress and obstacles have been seen with efforts to employ them for therapeutic benefit.     

Severe food allergy as a variant of IPEX syndrome caused by a deletion in a noncoding region of the FOXP3 gene

BACKGROUND & AIMS: Immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX; OMIM 304930) syndrome is a congenital syndrome characterized by autoimmune enteropathy, endocrinopathy, dermatitis, and other autoimmune phenomena. In the present work, we aimed to uncover the molecular basis of a distinct form of IPEX syndrome presenting at the edge of autoimmunity and severe allergy. METHODS: The FOXP3 gene was sequenced, FOXP3 messenger RNA (mRNA) was quantified by real-time polymerase chain reaction (PCR), and protein expression in peripheral blood lymphocytes was analyzed by flow cytometry after intracellular staining. In coculture experiments (CD4(+)CD25(-) and CD4(+)CD25(+) cells), the functions of regulatory T cells were analyzed. Expression of interferon gamma and interleukin 2 and 4 mRNA within the inflamed intestinal mucosa was quantified by real-time PCR. RESULTS: Here, we describe a distinct familial form of IPEX syndrome that combines autoimmune and allergic manifestations including severe enteropathy, food allergies, atopic dermatitis, hyper-IgE, and eosinophilia. We have identified a 1388-base pair deletion (g.del-6247_-4859) of the FOXP3 gene encompassing a portion of an upstream noncoding exon (exon -1) and the adjacent intron (intron -1). This deletion impairs mRNA splicing, resulting in accumulation of unspliced pre-mRNA and alternatively spliced mRNA. This causes low FOXP3 mRNA levels and markedly decreased protein expression in peripheral blood lymphocytes of affected patients. Numbers of CD4(+)CD25(+)FOXP3(+) regulatory T cells are extremely low, and the CD4(+)CD25(+) T cells that are present exhibit little regulatory function. CONCLUSIONS: A new mutation within an upstream noncoding region of FOXP3 results in a variant of IPEX syndrome associating autoimmune and severe immunoallergic symptoms.     

Hyperexpression of inducible costimulator and its contribution on lamina propria T cells in inflammatory bowel disease

BACKGROUND & AIMS: To investigate the role of inducible costimulator (ICOS), a new member of the CD28 family involved in regulation of T-cell activation and chronic intestinal inflammation, we assessed its expression and functional role in patients with inflammatory bowel disease (IBD). METHODS: Expression of ICOS, CD28, and cytotoxic T-lymphocyte antigen (CTLA) 4 on intestinal lamina propria mononuclear cells (LPMC) from patients with ulcerative colitis (UC), Crohn's disease (CD), and normal controls was determined using flow cytometry and immunohistochemistry. Expressions of the ICOS ligand, B7h, on lamina propria B cells, macrophages, and epithelial cells (EC) in the intestinal mucosa were also determined using flow cytometry. The functional costimulatory effect of ICOS on LPMC was assessed by the proliferative response and cytokine production. RESULTS: CD4(+) LPMC expressing ICOS was significantly increased in the inflamed mucosa of IBD patients but not in inflammatory or normal controls. B7h was also significantly up-regulated on B cells, macrophages, and EC in inflamed mucosa of IBD patients. Proliferative responses of anti-CD3/ICOS costimulation were significantly higher compared with those of anti-CD3 monoclonal antibody (mAb) alone. Anti-CD3/ICOS-stimulated-LPMC from UC secreted significantly increased amounts of interleukin (IL)-5 among the 3 groups. In contrast, anti-CD3/ICOS-stimulated-LPMC from CD secreted significantly increased amounts of interferon (IFN)-gamma in the presence of IL-12. CONCLUSIONS: Highly expressed ICOS in activated CD4(+) LPMC of IBD patients contributes to the dysregulated immune responses in IBD. Because ICOS hyperexpression was limited to inflammatory sites in IBD patients, ICOS would be a feasible therapeutic target for the treatment of IBD.     

强直性脊柱炎患者外周血CD4^＋CD25^＋CD127^low/-T细胞检测及其意义△

目的检测CD4^＋CD25^＋CD127^low/-T细胞在强直性脊柱炎（ankylosing spondylitis，AS）患者外周血的表达，并分析其与CD4^＋CD25^＋FOXP3^＋T细胞的相关性。方法 以21例AS患者外周血为研究组，20例类风湿关节炎（rheumatoid arthritis，RA）患者和24名正常人外周血作为对照组，采用三色直接荧光素标记法和多参数流式细胞仪检测外周血CD4^＋CD25^＋CD127^low/-T细胞、CD4^＋CD25^high细胞及CD4^＋CD25^＋FOXP3^＋T细胞的比例，同时检测外周血C反应蛋白（C-reactive protein，CRP）、血沉（ESR）、免疫球蛋白、补体等水平以及HLA—B27并进行相关性分析。结果与正常对照组相比，AS患者外周血CD4^＋CD25^＋CD127^low/-T及CD4^＋CD25^＋FOXP3＋T细胞百分率降低（均P〈0．05）。CD4^＋CD25^＋细胞百分率升高（P〈0．05）；CD4^＋CD25^＋CD127^low/-T细胞与CD4^＋CD25^＋FOXP3^＋T细胞呈正相关（r=0．589，P=0．021），与CRP、ESR、血小板及免疫球蛋白（IgG、IgA、IgM）和补体（C3、C4）、BASDAI、HLA-B27等均无明显相关性（均P〉0．05）。AS患者外周血CD4^＋CD25^＋CD127^low/-T细胞、CD4^＋CD25^＋FOXP3^＋T细胞和CD4＋CD25^highT细胞的百分率与RA患者外周血比较差异均无统计学意义（P〉0．05）。结论AS患者外周血CD4^＋CD25^＋CD127^low/-T细胞降低，且与CD4^＋CD25^＋FOXP3^＋T细胞呈正相关，提示在调节性T细胞研究中CD127具有替代FOXP3的可能性。     

CD4+CD25+CD127low/-T淋巴细胞在类风湿关节炎患者外周血中的表达及意义

目的 检测调节性T淋巴细胞新旧标志在活动性类风湿关节炎(RA)患者外周血中的表达,探讨用CD127代替FOXP3对调节性T淋巴细胞进行研究的可能性.方法 选取活动性RA患者32例,其中未经缓解病情抗风湿药(DMARDs)治疗者20例,经DMARDs治疗效果不佳者12例,以25例原发性干燥综合征(pSS)患者和24名健康人作为对照,采用流式细胞术检测外周血中CD4+CD25high、CD4+CD25+CD127low/-及CD4*CD25+FOXP3+T淋巴细胞的比例,同时检测外周血C反应蛋白(CRP)、红细胞沉降率(ESR)、免疫球蛋白、补体等水平并进行相关性分析.结果 RA患者CD4+CD25highT淋巴细胞百分率与健康对照组相比差异无统计学意义(P>0.05).其CD4+CD25+FOXP3+T淋巴细胞与CD+CD25+CD127low/-T淋巴细胞的百分率均低于健康对照组(P<0.05),但CD4+D25+FOXP3+、CD4+CD25+CD127low/-T淋巴细胞在RA患者与pSS患者中的表达差异无统计学意义(P>0.05);这三群细胞的表达水平在RA未经治疗组和治疗效果不佳组之间差异均无统计学意义(P>0.05). RA患者CD4+CD25+FOXP3+T淋巴细胞与CD4+CD25+CD127low/-T淋巴细胞之间呈明显正相关(r=0.698,P=0.001),但这两群细胞与患者的CRP、ESR等水平及抗环瓜氨酸肽(CCP)抗体、类风湿因子(RF)均无相关性(P>0.05).结论 活动性RA患者外周血中,CD4+CD25+CD127low/-T淋巴细胞的百分率降低,并且与CD4+CD25+FOXP3+T淋巴细胞呈显著正相关性,提示CD127可能被作为Treg细胞中FOXP3的替代标记.     

CD8+CD28- regulatory T lymphocytes prevent experimental inflammatory bowel disease in mice

BACKGROUND & AIMS: Immune responses to innocuous intestinal antigens appear tightly controlled by regulatory T lymphocytes. While CD4+ T lymphocytes have recently attracted the most attention, CD8+ regulatory T-cell populations are also believed to play an important role in control of mucosal immunity. However, CD8+ regulatory T-cell function has mainly been studied in vitro and no direct in vivo evidence exists that they can control mucosal immune responses. We investigated the capacity of CD8+CD28- T cells to prevent experimental inflammatory bowel disease (IBD) in mice. METHODS: CD8+CD28- regulatory T cells were isolated from unmanipulated mice and tested for their capacity to inhibit T-cell activation in allogeneic mixed lymphocyte cultures in vitro and to prevent IBD induced by injection of CD4+CD45RB(high) cells into syngeneic immunodeficient RAG-2 mutant mice. RESULTS: CD8+CD28- T lymphocytes inhibited proliferation and interferon gamma production by CD4+ responder T cells in vitro. CD8+CD28- regulatory T cells freshly isolated from spleen or gut efficiently prevented IBD induced by transfer of colitogenic T cells into immunodeficient hosts. Regulatory CD8+CD28- T cells incapable of producing interleukin-10 did not prevent colitis. Moreover, IBD induced with colitogenic T cells incapable of responding to transforming growth factor beta could not be prevented with CD8+CD28- regulatory T cells. CD8+CD28+ T cells did not inhibit in vitro or in vivo immune responses. CONCLUSIONS: Our findings show that naturally occurring CD8+CD28- regulatory T lymphocytes can prevent experimental IBD in mice and suggest that these cells may play an important role in control of mucosal immunity.     

Functional CD4+CD25high regulatory T cells are enriched in the colonic mucosa of patients with active ulcerative colitis and increase with disease activity

BACKGROUND: Factors determining the extension and degree of inflammation in the colonic mucosa of patients with ulcerative colitis (UC) are largely unknown, but CD4+CD25high regulatory T cells (Tregs) have been implicated to play an important role in suppressing inflammation. Therefore, the aims of this study were to determine whether colonic Tregs have suppressive effects on colonic effector T cells in UC and to analyze the association between segmental colonic Treg distribution and disease activity. MATERIALS AND METHODS: The suppressive activity of colonic CD4+CD25high Tregs from patients with active UC was determined in coculture assays measuring proliferation and cytokine production. The frequency of Tregs and the expression of the Treg marker FOXP3 were analyzed with flow cytometry and RT-PCR in isolated cells and the whole mucosa from patients with active and inactive disease, as well as healthy mucosa. RESULTS: Colonic CD4+CD25high T cells from patients with UC suppressed the proliferation and cytokine secretion of colonic effector CD4+ T cells. Healthy controls but not patients with UC had lower Treg frequencies in the sigmoid than in the ascending colon. Patients with UC with active disease had increased frequency of colonic Tregs. The frequency of Tregs was positively correlated with colonic disease activity and serum C-reactive protein. CONCLUSIONS: Colonic CD4+CD25high Tregs are able to suppress colonic effector T cell activity in vitro, and the Treg frequency in the inflamed intestine increases with disease activity in patients with active UC. This suggests that Tregs may be outnumbered by other inflammatory cells or that their suppressive activity may be influenced by the in vivo environment.     

FOXP3在炎症性肠病患者外周血和肠黏膜中的表达特点

背景：炎症性肠病（IBD）的发病与一系列免疫异常有关。免疫反应受特定的免疫调节细胞调控，包括CD4^＋CD25^＋T细胞．而CD4^＋CD25^＋T细胞的发育和功能可能受FOXP3基因调控。目的：研究FOXP3的表达特点以及IBD时FOXP3表达的改变。方法：以免疫磁珠分离CD4^＋、CD4^＋CD25^＋和CD4^＋CD25^-T细胞。以逆转录聚合酶链反应（RT-PCR）和蛋白质印迹法检测IBD患者和非IBD对照外周血单个核细胞（PBMC）、肠固有层单个核细胞（LPMC）和肠黏膜组织中FOXP3的表达。结果：CD4^＋CD25^＋T细胞中FOXP3 mRNA的表达明显强于CD4^＋T细胞和未分离的PBMC或LPMC。T细胞受体（TCR）激活后，或经白细胞介素（IL）-2、IL-15作用后，PBMC或LPMC FOXP3 mRNA或蛋白表达明显增强。12例IBD中9例（75．0％）肠黏膜LPMC中检测到FOXP3 mRNA表达，高于对照肠黏膜的47．1％（8／17．P〉0．05）。未受刺激的IBD和对照肠黏膜组织中未检测到FOXP3 mRNA表达。结论：人类FOXP3的表达受T细胞活化影响。IBD患者肠黏膜LPMC中FOXP3 mRNA的表达率有增高的趋势．但与对照肠黏膜相比无显著差异．     

Evaluation of CD4+/CD25+/high/CD127low/- Regulatory T Cells in Rheumatoid Arthritis Patients

Background: Rheumatoid arthritis (RA) is the most common rheumatoid disease of unknown etiology, determined by the articular cartilage destruction and bone loss. The hallmark of RA is the defect in immune tolerance. Regulatory T cells (Treg) play a critical role in the protection of peripheral tolerance. Objective:  To assess the percentage of CD4+/CD25+/high/CD127low/- Treg cells in peripheral blood of RA patients as compared with the healthy individuals. Methods: The number of CD4+/CD25+/high/CD127low/- Treg cells was assessed by multicolor flow cytometry. The clinical disease activity of RA patients was determined by disease activity score 28 (DAS-28). The correlations of DAS-28 and erythrocyte sedimentation rate (ESR) with Treg cells were evaluated. Results: The percentage of CD4+/CD25+/high/CD127low/- Treg cells in peripheral blood of RA patients significantly decreased as compared with the healthy individuals (P= 0.0002). The percentage of CD4+/CD25+/high/CD127low/- Treg cells negatively correlated with DAS-28 and ESR. Conclusion: This study concludes that the defect of Treg cells plays a vital role in the pathogenesis of this disease. Further studies are necessary to determine the role of Treg cells in the clinical course of rheumatoid arthritis.     

FOXP3 expression accurately defines the population of intratumoral regulatory T cells that selectively accumulate in metastatic melanoma lesions

Regulatory T (T(reg)) cells are often found in human tumors; however, their functional characteristics have been difficult to evaluate due to low cell numbers and the inability to adequately distinguish between activated and T(reg) cell populations. Using a novel approach, we examined the intracellular cytokine production capacity of tumor-infiltrating T cells in the single-cell suspensions of enzymatically digested tumors to differentiate T(reg) cells from effector T cells. Similar to T(reg) cells in the peripheral blood of healthy individuals, tumor-infiltrating FOXP3(+)CD4 T cells, unlike FOXP3(-) T cells, were unable to produce IL-2 and IFN-gamma upon ex vivo stimulation, indicating that FOXP3 expression is a valid biological marker for human T(reg) cells even in the tumor microenvironment. Accordingly, we enumerated FOXP3(+)CD4 T(reg) cells in intratumoral and peritumoral sections of metastatic melanoma tumors and found a significant increase in proportion of FOXP3(+)CD4 T(reg) cells in the intratumoral compared with peritumoral areas. Moreover, their frequencies were 3- to 5-fold higher in tumors than in peripheral blood from the same patients or healthy donors, respectively. These findings demonstrate that the tumor-infiltrating CD4 T(reg) cell population is accurately depicted by FOXP3 expression, they selectively accumulate in tumors, and their frequency in peripheral blood does not properly reflect tumor microenvironment.     

Angiogenesis as a novel component of inflammatory bowel disease pathogenesis

BACKGROUND & AIMS: Angiogenesis is a critical component of neoplastic and chronic inflammatory disorders, but whether angiogenesis also occurs in inflammatory bowel disease (IBD) has yet to be established. We assessed mucosal vascularization, expression of endothelial alphaVbeta3 integrin, angiogenic factors, and their bioactivity in Crohn's disease (CD) and ulcerative colitis (UC) mucosa. METHODS: Mucosal endothelium was immunostained for CD31 and factor VIII and quantified by digital morphometry. alphaVbeta3 expression was studied in vivo by confocal microscopy and in vitro by flow cytometric analysis of human intestinal microvascular endothelial cells (HIMECs). Vascular endothelial growth factor (VEGF), interleukin (IL)-8, and bFGF levels were measured in mucosal extracts and cells and angiogenic bioactivity shown by induction of HIMEC migration and the corneal and chorioallantoic membrane angiogenesis assays. RESULTS: Microvessel density was increased in IBD mucosa. Endothelial alphaVbeta3 was strongly expressed in IBD but only sporadically in normal mucosa and was up-regulated in HIMECs by VEGF, tumor necrosis factor alpha, and bFGF. IBD mucosal extracts induced a significantly higher degree of HIMEC migration than control mucosa, and this response was mostly dependent on IL-8 and less on basic fibroblast growth factor or vascular endothelial growth factor. Compared with normal mucosa, IBD mucosal extracts induced a potent angiogenic response in both the corneal and chorioallantoic membrane assays. CONCLUSIONS: These results provide morphological, phenotypic and functional evidence of potent angiogenic activity in both CD and UC mucosa, indicating that the local microvasculature undergoes an intense process of inflammation-dependent angiogenesis. Thus, angiogenesis appears to be an integral component of IBD pathogenesis, providing the practical and conceptual framework for anti-angiogenic therapies in IBD.