溃疡性结肠炎患者外周血CD4+CD25+Treg细胞的表达及其意义

探讨CD4 CD25 Treg细胞在溃疡性结肠炎(UC)发病中的作用及其与疾病活动性的关系。采用三色流式细胞术检测52例UC患者,30例其它肠病患者和30名对照者。UC患者中活动期的30例,稳定期的22例,使用和未使用激素和/或免疫抑制剂活动期UC患者分别为18例和12例。对以上各组外周血中CD4 CD25 Treg细胞亚群的百分率进行测定。结果显示,活动期UC患者外周血CD4 CD25 Treg细胞比例明显低于其他肠病和对照组(P<0.001);疾病活动期UC患者外周血CD4 CD25 Treg细胞比例明显低于疾病稳定期患者(P<0.001);活动期UC患者中使用激素和/或免疫抑制剂与未使用激素和/或免疫抑制剂结果差异有统计学意义;UC患者外周血CD4 CD25 Treg细胞表达率与疾病活动指数评分呈负相关性,提示UC患者外周血CD4 CD25 Treg细胞异常表达,可能参与疾病的发生发展,与疾病的活动性密切相关。     

HLA Class-I-Restricted and Colon-Specific Cytotoxic T Cells from Lamina Propria Lymphocytes of Patients with Ulcerative Colitis

We established cytotoxic T-lymphocyte (CTL) lines against colonic epithelial cell line from LPLs of patients with ulcerative colitis by continuous stimulation with human lymphocyte antigen A (HLA-A) matched colonic epithelial cell lines and clones from LPLs using polyclonal stimulation with phytohemagglutinin. The established CTL lines and clones showed cytotoxicity against HLA-A-matched colonic epithelial cell line but not against HLA-mismatched colonic epithelial cell lines, and HLA-A-matched lung and esophagus cell lines. The CTL response was HLA class I-restricted and mediated by CD8-positive T-lymphocytes. Moreover, the CTL line showed cytotoxicity against autologous B-LCLs pulsed with peptides extracted from HLA-A-matched colonic epithelial cell line but not against other organ-derived peptides pulsed and unpulsed autologous B-LCLs. CTL lines and clones established from LPLs of patients with ulcerative colitis showed colon-specific and HLA class I-restricted killing of human colonic epithelial cell line, suggesting that these CTLs may play a role in colonic epithelial cell damage in some patients with ulcerative colitis.     

晚期肺癌患者调节性T细胞和IL-10表达的变化

探讨晚期肺癌患者的CD4＋CD25＋调节性T细胞（Treg）、IL-10及其他T细胞亚群表达的临床意义。检测晚期肺癌患者92例和正常对照者64名的IL-10（ELISA法）、CD4＋CD25＋调节性T细胞及其他T细胞亚群（流式细胞仪法）。结果显示：肺癌组血清IL-10明显大于对照组（278±34ng/L vs 122±65ng/L,P〈0.01）、CD4＋CD25＋Treg细胞明显大于对照组[（17.8±5.2）%vs（7.1±0.4）%,P〈0.01]、CD3＋、CD4＋、CD8＋CD28＋和NK细胞明显小于对照组[（58.4±7.8）%vs（78.2±6.4）%,P≤0.05;（34.4±7.6）%vs（44.9±8.4）%,P〈0.01;（9.4±3.6）%vs（16.5±2.7）%,P〈0.01;（9.4±3.6）%vs（18.5±7.2）%,P〈0.01]。CD8＋T细胞明显高于对照组[（37.8±6.5）%vs（31.8±5.1）%,P〈0.01]。CD4＋CD25＋Treg细胞、IL-10与CD8＋CD28＋细胞、NK细胞呈明显负相关。这些结果表明,CD4＋CD25＋Treg细胞与IL-10增多为晚期肺癌患者免疫功能受损的表现。     

The Serum Factor from Patients with Ulcerative Colitis that Induces T Cell Proliferation in the Mouse Thymus Is Interleukin-7

The disturbance of immune regulatory T cells is related to the pathogenesis of ulcerative colitis. Here we demonstrated and characterized the serum factor from ulcerative colitis patients that induced proliferation of intrathymic T cells. The factor isolated from the patient sera by a combination of gel filtration and anion-exchange chromatography induced proliferation of CD4⁺CD8^– intrathymic T cells in the organ-cultured embryonic mouse thymus. Purification and amino acid sequence analysis of the serum factor demonstrated that the N-terminal 12 sequence was homologous to that of interleukin-7. SDS-PAGE and Western blot confirmed that purified serum factor was interleukin-7. Enzyme immunoassay demonstrated that the serum interleukin-7 concentration was significantly increased in the patients. PCR and Southern blot hybridization demonstrated that interleukin-7 mRNA expression was increased in the thymus tissues from patients but decreased in the colonic mucosa. Since interleukin-7 is a crucial cytokine for proliferation and differentiation of T cells in the thymus, the present study indicates that interleukin-7 may contribute to the disturbance of immune regulatory T cells in ulcerative colitis.     

Regulatory B Cells and Mechanisms

Regulatory B cells have gained prominence in their role as modulators of the immune response against tumors, infectious diseases, and autoimmune diseases, such as systemic lupus erythematosus, rheumatoid arthritis, and multiple sclerosis, among others. The concept of regulatory B cells has been strongly associated with interleukin (IL)-10 production; however, there is growing evidence that supports the existence of other regulatory mechanisms, such as the production of transforming growth factor β (TGF-β), induced cell death of effector T cells, and the induction of CD4⁺CD25^?Foxp3⁺ regulatory T cells. The regulatory function of B cells has been associated with the presence and activation of molecules such as CD40, CD19, CD1d, and BCR. Alterations in signaling by any of these pathways leads to a marked defect in regulatory B cells and to increased clinical symptoms and proinflammatory signs, both in murine models and in autoimmune diseases in humans. B cells mainly exert their regulatory effect through the inhibition of proliferation and production of proinflammatory mediators, such as TNF-α, IFN-γ, and IL-17 by CD4⁺ T cells. A better understanding of how regulatory B cells function will offer new perspectives with regard to the treatment of various human diseases.     

Special regulatory T-cell review: Regulatory T cells and the intestinal tract--patrolling the frontier

Tolerance to self and harmless antigens is one of the central features of the immune system, and it is obtained through a combination of multiple mechanisms. Discriminating between pathogens and non-pathogenic antigens is especially important in the intestine, which constitutes the main contact surface between the body and the outside environment. Recently, the role of Foxp3+ regulatory T cells (Treg) in the establishment and maintenance of tolerance has been the focus of numerous studies. In this review, we briefly discuss the historical background leading to the identification of Foxp3+ Treg and give an overview of their role in controlling systemic and mucosal immune responses.     

溃疡性结肠炎发病时组织及血清中IL-8水平的变化

目的 :检测溃疡性结肠炎患者 (UC)的组织及血清中白细胞介素 - 8(IL - 8)的含量 ,了解其在溃疡性结肠炎发病中的作用。方法 :收集 34例经内镜检查证实的UC患者结肠黏膜组织和血清标本 ,采用放射免疫分析检测IL - 8的含量。并与正常对照组进行比较。结果 :UC组中病变局限组血清和组织中IL - 8含量分别为(1 81 5 7± 2 6 6 7)ng/L、(71 4 80± 1 84 30 )pg/mg病变广泛组血清和组织中IL - 8含量分别为 (2 1 7 91± 5 8 1 1 )ng/L、(1 0 5 6 5 0± 30 8 1 0 )pg/mg与 32例正常对照组患者比较有显著性差异。结论 :UC患者的组织和血清中IL - 8含量明显升高 ,随着病变范围的扩大和病变程度的增加 ,其含量亦有增高的趋势     

Acarbose: A New Option in the Treatment of Ulcerative Colitis by Increasing Hydrogen Production

Acarbose, which is clinically widely used to treat Type 2 Diabetes, is thought to act at the small intestine by competitively inhibiting enzymes that delay the release of glucose from complex carbohydrates, thereby specifically reducing post prandial glucose excursion. The major side-effect of treatment with acarbose, flatulence, occurs when undigested carbohydrates are fermented by colonic bacteria, resulting in considerable amount of hydrogen. We propose that enteric benefits of acarbose is partly attributable to be their ability to neutralise oxidative stress via increased production of H₂ in the gastrointestinal tract. Therefore, symptoms of ulcerative colitis in human beings can be ameliorated by acarbose.     

T Regulatory Cells in Allergen-Specific Immunotherapy

A dramatic increase in the prevalence of allergy and asthma has occurred during the past few decades. Although the symptoms of many allergic disorders can be suppressed quite effectively by pharmacological interventions, these do not provide a curative solution and therefore involve lifelong use of medication. Allergen-specific immunotherapy (SIT) on the other hand provides a long-lasting effect on the immune response to common environmental antigens, therefore allowing cessation of the therapy after several years. The changes in the immune response brought about by allergen-SIT are slowly being unveiled and explained. Mechanisms underlying allergen-SIT and in particular the role of regulatory T cells will be discussed in this review, based on recent findings and current concepts.     

Interplay Between Effector Th17 and Regulatory T Cells

Introduction  Over two decades ago, T helper cells were classified into its functional subsets. Soon after the classical observation of Mosmann et al., immunologists agreed to accept the Th1/Th2 paradigm of the T helper subsets. Each subset is not only characterized by its specific cytokines pattern and effector functions but also by their properties to counter regulate each other’s functions. This classification helped to understand the complex principles of T helper cell biology and allowed us to comprehend different immune reactions in context of Th1 and Th2 subsets. Discussion  Although Th1 subsets thought to be the crucial player for most of the organ-specific autoimmune diseases like multiple sclerosis and type-1 diabetes but the loss of Th1 dominant cytokine, IFN-γ did not prevent the development of autoimmunity which raised the possibility of involvement of other Th subsets, different from Th1 cells in the induction of autoimmunity. Conclusion  Recently, a new subset of Th cells that predominantly produce IL-17 and induce autoimmunity has been discovered, and it is believed that this subset may be the major cell type involved in orchestrating tissue inflammation and autoimmunity. Recent data propose that the differentiation factors of Th17 cells reveal a link with induction of Foxp3⁺ regulatory T cells. Here, we review the interplay between Th17 and Foxp3⁺ T-reg cells and Tr1 cells during autoimmune inflammatory reaction.     

The Effects of Silymarin and Cyclosporine A on the Proliferation and Cytokine Production of Regulatory T Cells

Background: Immunosuppressive agents are necessary to enhance allograft tolerance after transplantation and the treatment of autoimmune disorders. Regulatory T cells (Tregs) play a pivotal role in improving allograft tolerance and determining the fate of transplanted organs. Therefore, the aim of this study was to investigate the immunomodulatory effects of cyclosporine A (CsA) and silymarin on the proliferation and cytokine production of Tregs.

Methods: Peripheral blood mononuclear cells (PBMCs) were obtained from healthy voluntaries and Tregs were isolated using an immunomagnetic separation method. The phenotypic characteristics of Tregs were determined by flow cytometry. Tregs were expanded and then cultured with different concentrations of CsA and silymarin. The effects of CsA and silymarin on the viability, proliferation, and transforming growth factor-beta 1 (TGF-β1) production of Tregs were determined after 3 and 5 days of culture.

Results: CsA significantly decreased Treg proliferation in a dose-dependent manner (p < 0.01–0.05). CsA failed to change TGF-β1 production of Tregs. On the contrary, silymarin significantly increased the proliferation of Tregs (p < 0.01–0.05). A statistically significant increase was also observed in the TGF-β1 production of Tregs (p < 0.01–0.05). Our data showed that Treg viability was not compromised by CsA and silymarin.

Conclusion: Overall, the results of this study for the first time indicate that silymarin, unlike CsA, has the ability to increase the proliferation and TGF-β1 production of Tregs and may be beneficial in the treatment of autoimmune disorders and improvement of Treg-dependent allograft tolerance after transplantation.     

Minireview: Regulatory T Cells and Ovarian Cancer

ABSTRACT

In the last 15 years, it has become apparent that ovarian cancer is recognized by the immune system, taking into account that T cell infiltration can be associated with increased overall survival. Several studies indicate that a correct combination of cluster of differentiation 8 and cluster of differentiation 4 T cells is key to fight tumor progression and that the presence of regulatory T cells (Tregs) infiltrating ovarian solid tumors (or present in ascites) is deleterious. Several markers that characterize Tregs include glucocorticoid-induced tumor necrosis factor receptor, cytotoxic T lymphocyte antigen-4, and forkhead box protein 3 (Foxp3). Research has shown that Tregs can infiltrate cancerous tissue and contribute to tumor growth by secreting immunosuppressive cytokines such as transforming growth factor beta and interleukin (IL)-10. Importantly, these cells might hamper the efficacy of immunotherapeutic approaches, thus strategies involving depletion or regulation of this population have been proposed and tested in experimental models. In this Minireview, we will discuss the relevance of Tregs in ovarian cancer and the experimental approaches destined to impair their immunosuppressive effects.     

Stress Proteins as Inducers and Targets of Regulatory T Cells in Arthritis

Immunization with microbial or mammalian stress proteins or heat-shock proteins in models of experimental autoimmunity has been observed to lead to increased disease resistance. Furthermore, such immunization has been proposed to result in the induction and expansion of T cells that suppress disease upon transfer. Comparisons of microbial heat-shock proteins with other conserved immunogenic proteins of bacterial origin have indicated a unique capacity for heat-shock proteins to induce a regulatory phenotype in T cells, such as reflected by the production of IL10. Also, studies in children with chronic arthritis have indicated that T-cell responses to heat-shock proteins are associated with a benign course of the disease and with remission. Furthermore, in patients, heat-shock-protein-(HSP-) activated T cells were shown to display regulatory phenotypes consistent with CD4⁺CD25⁺ T regulatory cells.     

Regulatory T Cells in Autoimmune Diseases: Anti-Ergotypic T Cells

T regulatory cells play an important role in regulating T-cell responses to self-antigens and control autoimmunity and autoimmune disease. Anti-ergotypic T cells are a subset of such regulatory T cells that respond to activation markers, ergotopes, expressed on other activated T cells. Anti-ergotypic T cells do not respond to nonactivated T cells. Ergotopes include the α-chain of the IL-2 receptor (CD25). Anti-ergotypic T cells were found to downregulate experimental diseases such as experimental autoimmune encephalomyelitis (EAE) and adjuvant arthritis (AA). Anti-ergotypic T cells are present in humans and are activated after T-cell vaccination. Here we review anti-ergotypic T cells in animal models and in humans and contrast anti-ergotypic T cells with other regulatory T-cell subsets.     

Induction of IL-10 producing CD4+ T cells with regulatory activities by stimulation with IL-10 gene-modified bone marrow derived dendritic cells

Dendritic cells (DCs) can induce both tolergenic as well as effective immune responses in the lung. Pulmonary DCs producing interleukin (IL)-10 mediated tolerance induced by respiratory exposure to antigen. IL-10 is an important immunosuppressive cytokine, which inhibits maturation and function of DC. To assess whether IL-10 producing DCs can exert the tolergenic effect through the differentiation of regulatory T cells, bone marrow derived DCs were genetically modified by IL-10 expressing adenovirus. IL-10 gene modified DCs (Ad-IL-10-DC) displayed a characteristic phenotype of immature DCs. Here we showed that in vitro repetitive stimulation of naïve DO11·10 CD4⁺ T cells with Ad-IL-10-DCs resulted in a development of IL-10 producing T-cell regulatory cells. These T cells could not proliferate well but also lost their ability to produce interferon-γ upon restimulation with irradiated splenocytes and ovalbumin peptide. Furthermore, in co-culture experiments these T cells inhibited the antigen-driven proliferation of naïve CD4+ T cells in a dose-dependent manner. Our findings demonstrated that IL-10 producing DCs had the potential to induce the differentiation of Tr1-like cells and suggested their therapeutic use.     

CD4+CD25+调节性T细胞及血小板参数在重症肺炎患者中表达的意义

目的 探讨CD4+ CD25+调节性T细胞及血小板参数在重症肺炎患者中表达的意义.方法 收集2013年5月至2015年10月我院诊断为肺炎的患者,共计80例,进一步分为重症肺炎组28例和肺炎组52例.对照组为同期健康体检者,共50例.对比重症肺炎组、肺炎组和对照组入院时CD4+ CD25+调节性T细胞及血小板参数水平,并且分析重症肺炎组死亡患者与存活患者入院时CD4+ CD25+调节性T细胞及血小板参数水平.结果 ①重症肺炎组、肺炎组和对照组入院时CD4+ CD25+调节性T细胞水平、MPV及PLT结果比较有差异(P＜0.05);重症肺炎组、肺炎组和对照组入院时PDW、PCT结果比较无差异(P＞0.05).②重症肺炎组死亡患者与存活患者入院时CD4+ CD25+调节性T细胞水平、MPV及PLT结果比较有差异(P＜0.05);重症肺炎组死亡患者与存活患者入院时PDW、PCT结果比较无差异(P＞0.05).结论 CD4+ CD25+调节性T细胞、MPV及PLT可作为反应肺炎严重程度的敏感指标,并且可作为评价重症肺炎患者预后的客观指标.     

Mesenchymal Stem Cell-Mediated Immature Dendritic Cells Induce Regulatory T Cell-Based Immunosuppressive Effect

Immature dendritic cells (imDCs) are increasingly viewed as mediators of T-cell tolerance. We investigated factors enabling induction of regulatory T (Treg) cells through syngeneic imDC/mesenchymal stem cell (MSC) co-cultures in vitro and immunosuppressive effects of MSC-mediated imDCs (MSCs were excluded after 72 h co-culture) in vivo. In these experiments, we found that Foxp3⁺ Treg cell population remarkably increased after the T cell priming phase when splenocytes were co-cultured with both imDCs and MSCs, presumably inducing naïve T cells into Treg cells by MSCs and imDCs. In parallel, TGF-β secretion was markedly induced from the imDC+MSC+splenocyte culture supernatant to a significant level at 72-h co-culture, compared to the MSC or imDC+splenocyte co-culture. Based on these results, using a murine melanoma tumor model, we confirmed that the subcutaneous injection of B16 cells induced a perfect tumor incidence in allogeneic recipients when MSC-mediated DCs were coinjected. Consequently, these results suggested that immune tolerance with MSC-mediated DCs leads to immunosuppression induced by at least Foxp3-specific Treg cells. This tool may be useful in clinical trials due to the yet unknown side effects of stem cell therapy.     

Regulatory T Cells in Lupus

Naturally occurring, CD4⁺CD25⁺ regulatory T cells that are exported from the thymus early in life play an important role in controlling organ-specific autoimmune diseases, but they may not be critical for suppressing systemic autoimmunity in lupus. On the other hand, lupus-prone subjects appear to be deficient in generation of adaptive T-regulatory cells that can be induced by various means. We review autoantigen-specific therapeutic approaches that induce such regulatory T cells. Of particular interest are TGF-β producing CD4⁺CD25⁺ and CD8⁺ regulatory T cells that are induced by low dose tolerance therapy of lupus-prone mice with nucleosomal histone peptide epitopes, administered subcutaneously in subnanomolar doses. These regulatory T cells are not only efficient in suppressing autoantigen recognition and autoantibody production, but they also inhibit migration/accumulation of pathogenic autoimmune cells in the target organ, such as the kidneys of mice prone to develop lupus nephritis. We discuss why and under what conditions such therapeutic approaches would be beneficial in lupus patients and lupus-prone subjects.     

Regulatory T Cells and Cancer: A Two-Sided Story

ABSTRACT

Regulatory T cells (Tregs) play pivotal roles in limiting the duration and magnitude of immune response against infectious agents and self-antigens. This is accomplished through contact-dependent and -independent mechanisms that involve crosstalk between Treg cells and other immune and tissue-specific cell types. The same machinery is employed by Tregs to regulate immune responses to cancer, limiting both pro-tumor inflammation and anti-tumor immunity. Factors produced by Treg cells also act directly on transformed epithelial cells and exert opposing effects during different stages of cancer development. Therefore, the immune regulatory cell population serves as a double-edged sword for the development, progression, and treatment of cancers. In this review, we summarize current knowledge on the roles of Treg lymphocytes during cancer development, as well as the underlying cellular and molecular mechanism.     

Generation of MHC Class I-Restricted Cytotoxic T Cell Lines and Clones Against Colonic Epithelial Cells from Ulcerative Colitis

We established CTL lines and clones against colonic epithelial cells from PBLs of patients with ulcerative colitis by continuous stimulation with HLA-A locus-matched colonic epithelial cell lines. We developed a nonradioactive europium release cytotoxicity assay to detect CTLs. PBLs from 3 of 12 patients but not from any of 14 normal controls who shared at least one haplotype of HLA-A locus with two colonic epithelial cell lines, CW2 and ACM, showed increased cytotoxicity against these lines. Three CTL lines established from the PBLs of patients showed increased cytotoxicity against HLA-A locus-matched CW2 or ACM but not against matched lung or esophagus cell lines. The phenotypes of CTL lines were -TCR⁺CD3⁺CD8⁺CD16^–. The CTL line MS showed increased cytotoxicity against freshly isolated colonic epithelial cells but not against cells with a different HLA-A locus. Two CTL clones were generated from MS and clone 3-2, expressing CD3⁺CD8⁺CD4^–CD56^–, showed high MHC class I-restricted cytotoxicity against the colonic epithelial cells. These results indicated that CTLs against colonic epithelial cells may contribute to epithelial cell damage in ulcerative colitis.