人天然型和诱导型CD4+CD25+FoxP3+CD127-Treg细胞表型多样性的比较

BACKGROUND: Regulatory T cells (Treg) are classified into two subsets, nature Treg (nTreg) and induced Treg (iTreg). Although there is consensus that CD4+CD25+FoxP3+CD127- is the widely accepted phenotype of Treg, it remains unclear what is the difference in phenotypes including cytokine patterns of nTreg and iTreg. OBJECTIVE: To understand and compare the plasticity of nTreg and iTreg and to search the exact mechanism of cytokine secretion in Tregs. METHODS: We investigated the frequency and cytokine pattern of CD4+CD25+FoxP3+CD127-nTreg in freshly separated peripheral blood mononuclear cells of five healthy individuals using 8-color fluorescence flow cytometry (FACSCanto II). Subsequently, after 9 days of allostimulation in mixed lymphocytes, the frequency and cytokine pattern of CD4+CD25+FoxP3+CD127-iTreg were determined and analyzed. RESULTS AND CONCLUSION: In fresh cells, (1.5±0.70)% of CD4+ T cells were CD4+CD25+FoxP3+CD127- nTregs. Almost all these cells expressed interferon (IFN)-γ-, interleukin (IL)-2- or transforming growth factor-β+, and partial cells expressed IL-10+ or IL-10-. After 9-day allostimulation, the number of CD4+CD25+FoxP3+CD127- iTreg expressing IFN-γ+, IL-2-, IL-2+, IL-10+ or TGF-β+ increased strongly. The main subsets of human nTregs were CD4+CD25+FoxP3+CD127-IFN-γ-IL-2-IL-10+TGF-β+ and CD4+CD25+FoxP3+CD127-IFN-γ-IL-2-IL-10- TGF-β+ T cells. The proportion of each subset in CD4+ T cells was (1.1±0.59)% and (0.39±0.16)%, respectively. Whereas the main subsets of human iTregs were CD4+CD25+FoxP3+CD127-IFN-γ+IL-2-IL-10+TGF-β+ and CD4+CD25+FoxP3+CD127-IFN-γ+IL-2+IL-10+TGF-β+. Human nTregs were characterized as IFN-γ-IL-2- double negative, producing IL-10 and TGF-β or only TGF-β without IL-10, and not proliferating in vitro. During the allostimulation in mixed lymphocytes, IFN-γ+ iTregs proliferated remarkably. One-third of IFN-γ+ iTreg expressed IL-2+, and two-thirds of IFN-γ+ iTregs expressed IL-2, both of which produce IL-2 and TGF-β. Our results imply that CD4+CD25+FoxP3+CD127- Treg are potentially immunosuppressive probably because of their mandatory TGF-β and optional IL-10 production.  中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程       

肾移植患者外周血中的CD4+ CD25+ CD127low/-调节性T细胞

背景：越来越多的实验在分析免疫耐受标志,以期能够更好地辅助患者进行移植后免疫抑制治疗。 目的：分析肾移植后患者外周血中CD4⁺ CD25⁺ CD127^low/-调节性T细胞在肾移植免疫耐受中的作用。 方法：采集62例肾移植后患者(急性排斥反应组22例,移植稳定组40例)及20例健康对照者的外周抗凝血,经免疫染色,应用流式细胞仪分析CD4⁺ CD25⁺ CD127^low/-调节性T细胞所占CD4⁺ T细胞百分含量,同时采用ELISA方法检测患者血清中白细胞介素2和白细胞介素10的质量浓度。 结果与结论：移植稳定组中CD4⁺ CD25⁺ CD127^low/-调节性T细胞所占CD4⁺ T细胞百分含量显著高于健康对照组和急性反应排斥组(P < 0.01);CD4⁺ CD25⁺ CD127^low/-调节性T细胞百分含量与白细胞介素2呈显著负相关(P < 0.05),与白细胞介素10呈显著正相关(P < 0.01)。提示CD4⁺ CD25⁺ CD127^low/-调节性T细胞在肾移植后免疫耐受的机制中发挥了一定作用。     

Lower proportions of CD4+CD25high and CD4+FoxP3, but not CD4+CD25+CD127low FoxP3+T cell levels in children with autoimmune thyroid diseases

The essence of autoimmune thyroid disease (AITD) is loss of tolerance of own tissues caused by malfunction of T lymphocytes, which affects the production of antibodies reacting with particular cell structures and tissues. Foxp3⁺ regulatory T cells (Tregs) take part in the regulation of immune response and play a leading role in developing immune tolerance through active suppression. The aim of the study was to estimate the expression of CD4+CD25^high, CD4+CD25+CD127^lowFoxP3⁺ and CD4+ FoxP3 T cells in patients with Graves' disease (GD) (n = 24, median age 15.5 years), in patients with Hashimoto's thyroiditis (HT) (n = 30, median age 15 years) in comparison with sex- and age-matched healthy control subjects (n = 30, median age 15 years). Polychromatic flow cytometry using a FACSCalibur (BD Biosciences) cytometer was applied to delineate T regulatory cell populations. In untreated patients with Graves' disease and HT we observed a significant decrease in CD4+FoxP3 (p < 0.001, p < 0.01) and CD4+CD25^high (p < 0.016, p < 0.048) T lymphocytes as compared to the healthy control subjects. After 6–12 months of L-thyroxine therapy in HT cases these phenotypes of Tregs were normalized, yet no such changes were observed during GD therapy. The analysis of CD4+CD25+CD127^lowFoxP3⁺T cells in the peripheral blood revealed comparable percentages of these cells in patients with thyroid autoimmune diseases to the controls. We conclude that the reduction number of Tregs with CD4+CD25^high and CD4+FoxP3 phenotype suggests their role in initiation and development of autoimmune process in thyroid disorders.     

CD4+CD25+CD127dimFoxp3+ T cells are cytotoxic for human neurons

MS lesions are characterized by destruction of myelin and significant neuronal and axonal loss. Preliminary studies with the use of T(regs) in the mouse model of MS have been extremely encouraging. However, recent studies with human cells have shown the presence of different subpopulations of T cells within the CD4(+)CD25(+)Foxp3(+) T cell phenotype, some of which do not have regulatory functions. These findings suggest a potential difference between mouse and human in the regulatory phenotype. Here, we show that human activated CD4(+)CD25(+)Foxp3(+) T cells are neurotoxic in vitro. These cells expressed high levels of the cytotoxic molecule GrB and had no suppressive effect. On the contrary, they produced IFN-γ and low IL-17, suggesting a shift toward a T(H)1 phenotype. Thus, our data confirm the presence of a nonregulatory cytotoxic subpopulation within the human CD4(+)CD25(+)Foxp3(+) T cells and suggest further studies on the human regulatory phenotype prior to any potential therapeutic application.     

CTLA-4 x Ig converts naive CD4+CD25- T cells into CD4+CD25+ regulatory T cells

CTLA-4 x Ig was originally designed as an immunosuppressive agent capable of interfering with the co-stimulation of T cells. In the present study, we demonstrate that CTLA-4 x Ig, in combination with TCR ligation, has the additional capacity to convert naive CD4+CD25- T cells into Foxp3+ regulatory T (T(reg)) cells, as well as to expand their numbers. The CD4+CD25+Foxp3+ T(reg) generated by CTLA-4 x Ig treatment in vitro potently suppress effector T cells. Extending this in vivo, we show that systemic administration of CTLA-4 x Ig increases the percentage of CD4+CD25(hi)Foxp3+ cells within mixed lymphocyte reaction-induced murine lymph nodes. Significantly, the in vitro conversion of naive CD4+CD25- T cells into T(reg) cells is antigen-presenting cell (APC) dependent. This finding, together with the further observation that this conversion can also be driven in vitro by an antibody that engages B7-2 ligand, suggests that CTLA-4 x Ig-driven T(reg) induction may be predicated upon active CTLA-4 x Ig to B7-2 signaling within APC, which elicits from them T(reg)-inducing potential. These findings extend CTLA-4 x Ig's functional repertoire, and at the same time, reinforce the concept that T cell anergy and active suppression are not entirely distinct processes and may be linked by some common molecular triggers.     

黄芪注射液对NOD小鼠CD4~+CD25~+CD127~(-/low)调节性T细胞的影响

目的通过对NOD小鼠应用大剂量的黄芪注射液,观察黄芪对于CD~4+CD25~+CD127~-调节性T细胞及相关细胞因子的影响情况。方法随机将20只NOD小鼠分成4组,每组5只,分别给予生理盐水、环磷酰胺注射液、黄芪注射液、黄芪联合环磷酰胺注射液各0.6 ml,连续给药2周后,取小鼠脾脏制成脾细胞悬液上流式细胞仪检测CD4~+CD25~+CD127~(-/low)调节性T细胞水平,取小鼠外周血采用酶联免疫吸附实验法(ELISA)、检测小鼠血液中的IL-10、IL-6的变化情况。结果调节性T细胞的检测结果为黄芪注射液组及联合用药组较空白对照组和环磷酰胺组有显著差别(P<0.05),而环磷酰胺组与空白对照组比较没有显著差别(P>0.05)。IL-10的检测结果为,黄芪注射液组与联合用药组较空白对照组和环磷酰胺组有统计学意义(P<0.05)。IL-6的检测结果为,其余3组均与空白对照组比较明显降低IL-6的含量(P<0.05)。结论大剂量的黄芪注射液产生免疫调节作用,可能是通过提高Treg细胞的水平而达到抑制自身反应性T细胞的增殖和分化,以及同时提高细胞因子IL-10的水平,降低IL-6的水平,抑制炎症反应,共同达到...     

Distributional characteristics of CD25 and CD127 on CD4+ T cell subsets in chronic HCV infection

Attenuated CD4+ T-cell-mediated immune responses are involved in persistence of HCV infection, but the mechanism remains undefined. In this study, the proportions of CD4+ T cell subsets, naïve, central memory, effector memory and effector cells, along with CD25 (IL-2Rα) and CD127 (IL-7Rα) expression on different CD4+ T cell subsets, were measured by polychromatic flow cytometry in 24 chronic HCV-infected individuals and 21 healthy controls. A significant decrease in naïve CD4+ T cells and an increase of central memory and effector memory CD4+ T cells were found in HCV-infected patients compared with healthy controls. HCV-infected patients showed a lower level of CD127 expression in all CD4+ T cells subsets, especially in central memory and effector CD4+ T cells. In terms of total CD4+ T cells, an increase in CD25+ regular T cells (CD4+ CD25+ CD127lo) was found in HCV-infected patients. Interestingly, naïve CD4+ T cells showed increased CD25 expression, while effector memory and effector CD4+ T cells had lower CD25 expression. These data indicated that variations in different fractions of CD4+ T cells, including the phenotypic profile and expression level of CD25 and CD127, may be associated with low efficiency of immune response in chronic HCV infection. These results will strengthen the understanding of pathogenesis and dysfunction of CD4+ T cell immunity during long-term HCV persistence.     

CD4+ CD25+ [corrected] regulatory T cells render naive CD4+ CD25- T cells anergic and suppressive

CD4(+) CD25(+) Foxp3(+) naturally occurring regulatory T cells (nTreg) are potent inhibitors of almost all immune responses. However, it is unclear how this minor population of cells is capable of exerting its powerful suppressor effects. To determine whether nTreg mediate part of their suppressor function by rendering naive T cells anergic or by converting them to the suppressor phenotype, we cocultured mouse nTreg with naive CD4(+) CD25(-) T cells from T-cell receptor (TCR) transgenic mice on a RAG deficient (RAG(-/-)) background in the presence of anti-CD3 and interleukin-4 (IL-4) to promote cell viability. Two distinct responder cell populations could be recovered from the cocultures. One population remained undivided in the coculture and was non-responsive to restimulation with anti-CD3 or exogenous IL-2, and could not up-regulate IL-2 mRNA or CD25 expression upon TCR restimulation. Those responder cells that had divided in the coculture were anergic to restimulation with anti-CD3 but responded to restimulation with IL-2. The undivided population was capable of suppressing the response of fresh CD4(+) CD25(-) T cells and CD8(+) T cells, while the divided population was only marginally suppressive. Although cell contact between the induced regulatory T cell (iTreg) and the responders was required for suppression to be observed, anti-transforming growth factor-beta partially abrogated their suppressive function. The iTreg did not express Foxp3. Therefore nTreg are not only able to suppress immune responses by inhibiting cytokine production by CD4(+) CD25(-) responder cells, but also appear to modulate the responder cells to render them both anergic and suppressive.     

Effects of interleukin 4 on CD25+CD4+ regulatory T cell function

CD25+CD4+ regulatory T cells (Tregs) contribute to the maintenance of peripheral tolerance against self and non-self. The modulatory effects of cytokines, such as interleukin 4 (IL-4) on the function of Tregs have not been explored in detail. We here report that IL-4 prevents spontaneous apoptosis and the decline of foxp3 mRNA which were found to occur during culture of isolated Tregs. Tregs exposed to IL-4 were more potent in suppressing the proliferation of na?ve CD4+ T cells and they better inhibited IFN-gamma production by CD4+ T cells as compared to Tregs cultured in medium. IL-4 also enhanced membrane IL-2Ralpha (CD25) expression on Tregs above the levels observed on freshly isolated cells. IL-4-mediated effects on Treg function persisted in Tregs from Stat6-/- mice, pointing to a Stat6-independent intracellular transduction pathway. In conclusion, our data suggest that the anti-inflammatory function of IL-4 could partly be mediated by effects on Tregs function.     

Increased cytotoxicity of CD4+ invariant NKT cells against CD4+CD25hiCD127lo/- regulatory T cells in allergic asthma

CD4+CD25(hi)CD127(lo/-) regulatory T cells (Treg) have been implicated in the resolution of asthma-associated inflammation while the opposite role of CD4+ invariant NKT (iNKT) cells has been the subject of recent investigations. Studies here focused on mechanisms of interaction between CD4+ iNKT cells and Treg to further explore their roles in allergic asthma (AA). Flow cytometry analysis revealed a significant increase in the expression of the natural cytotoxicity receptors NKp30 and NKp46 by CD4+ iNKT cells in AA subjects compared to healthy controls (HC) and non-allergic asthmatics (NA). Subsequent intracellular staining showed that CD4+ iNKT cells also expressed higher levels of granzyme B and perforin in AA than HC. In in vitro killing assays, AA CD4+ iNKT cells selectively killed autologous Treg, but not CD4+CD25- T cells, more potently than HC and NA counterparts. This increased cytotoxicity positively correlated with asthma severity and granzyme B/perforin expression of CD4+ iNKT cells. Furthermore, it could be abrogated by either inhibition of the granzyme B-/perforin-dependent cell death pathway or oral corticosteroid administration. Altogether, these findings suggest that increased cytotoxicity of CD4+ iNKT cells against Treg might contribute to dysfunctional cellular interactions in AA.     

Decreased Levels of Circulating CD4+CD25+Foxp3+ Regulatory T Cells in Patients with Primary Antiphospholipid Syndrome

Introduction

CD4⁺CD25⁺Foxp3⁺ regulatory T (Treg) cell dysfunction has been documented in various autoimmune disorders, but not in antiphospholipid syndrome (APS) so far.

Methods

In this cross-sectional study, we aim to investigate CD4⁺CD25⁺Foxp3⁺ Treg cells, CD3⁺CD19^? T cells and CD3^?CD19⁺ B cells in patients with primary APS and healthy controls. Cell subtypes were immunophenotyped using specific monoclonal antibodies (anti-CD3 CY5, anti-CD4 FITC, anti-CD25, anti-Foxp3, anti-CD19 PE) and flow cytometry.

Results

Twenty patients with APS and 20 age- and sex-matched controls were studied. The percentage of total lymphocytes, activated Th cells (CD4+CD25+), Treg cells and CD3^?CD19⁺ B cells were found significantly lower in APS patients as compared to controls (all p?<?0.05).

Conclusion

A dysfunction in CD4⁺CD25⁺Foxp3⁺ Treg cells may represent one of the mechanisms leading to autoimmunity in APS patients. The decreased number of CD3^?CD19⁺ B cells of APS patients warrants further elucidation.     

CD4+CD25+CD127low调节性T细胞及相关细胞因子与慢性特发性血小板减少性紫癜的研究

目的:研究慢性特发性血小板减少性紫癜(CITP)患者外周血CD4+CD25+CD127low调节性T细胞及相关细胞因子的表达水平,探讨它们在ITP发病机制中的作用。方法:流式细胞术(FCM)检测31例ITP患者及25例健康志愿者外周血CD4+CD25+CD127low调节T细胞的数量,ELISA方法检测血清中IL-10、TGFβ-1的含量,并进行相关性分析。结果:ITP患者外周血CD4+CD25+CD127low调节性T细胞数量明显低于正常对照组(P<0.05),血清IL-10、TGFβ-1的含量也较正常对照组低(P<0.05)。CD4+CD25+CD127low调节性T细胞数量与IL-10的表达有相关性(P<0.05),与TGFβ-1的表达水平无相关(P>0.05)。结论:ITP患者CD4+CD25+CD127low调节T细胞数量减少及相关细胞因子的降低可能与ITP的细胞免疫失调有关。     

CD4+CD25+ T lymphocytes in human tonsils suppress the proliferation of CD4+CD25- tonsil cells

Animal studies define CD4+CD25+ T cells as a subset that protect against autoimmune inflammation. We wanted to investigate whether CD4+CD25+ T cells from patients with recurrent tonsillitis could suppress the proliferation of other tonsil cells, in vitro, as this immunological tissue also may serve as a model for chronic inflammation. Tonsil CD4+CD25+ cells markedly suppressed the proliferation of CD4+CD25- T cells in Concanavalin A-stimulated cocultures compared with cultures containing CD4+CD25- T cells only. The suppression exerted by the CD4+CD25+ cells was abrogated if these cells were irradiated before coculture or if interleukin (IL)-2 was added to the culture medium. CD4+CD25+ T cells proliferated poorly in response to mitogen, when cultured alone. Substitution with CD4+CD25+ T cells isolated from peripheral blood, enriched by similar methods, did not downregulate the proliferation of CD4+CD25- responder cells from tonsils. The augmented suppressive ability of tonsil CD4+CD25+ T cells compared with cells of this phenotype from blood, on CD4+CD25- responder cells from tonsils, suggests that there may be a functional difference between CD25+ cells from the two locations. In conclusion, CD4+CD25+ T cells from inflamed tonsils distinctly suppressed T-cell responses to mitogen in vitro, pointing to a regulatory role for CD4+CD25+ cells retrieved from inflammatory reactions in humans.     

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。     

重症肌无力患者外周血中CD4~+CD25~+调节性T细胞的变化及意义

研究CD4 + CD2 5 + 调节性T细胞在重症肌无力 (MG )发病中的作用。本文采用三色流式细胞术对 2 9例MG患者和 2 3例健康对照者外周血中CD4 + CD2 5 + T细胞 (CD3+ CD4 + CD2 5 + )的百分率进行测定。结果显示病情未能很好控制的MG患者外周血CD4 + CD2 5 + T细胞比率略低于健康对照组 (分别为 3 79%± 1 4 0 %、 4 5 3%± 0 96 % ,P =0 12 ) ,病情稳定或缓解的MG患者CD4 + CD2 5 + T细胞比率 (8 4 5 %± 1 96 % )显著高于健康对照组 (P =0 0 0 0 1) ;胸腺切除的MG患者CD4 + CD2 5 + T细胞比率 (8 4 4 %± 2 39% )显著高于非胸腺切除的MG患者 (5 88%± 2 89% ,P =0 0 38)和健康对照组 (4 5 3%± 0 96 % ,P =0 0 0 3)。提示MG患者外周血中存在异常比例的CD4 + CD2 5 + 调节性T细胞 ,可能参与疾病的发生与发展。     

Different thresholds of T cell activation regulate FIV infection of CD4+CD25+ and CD4+CD25- cells

Cellular activation plays an important role in retroviral replication. Previously, we have shown that CD4(+)CD25(+) T cells by the virtue of their partially activated phenotype represent ideal candidates for a productive feline immunodeficiency virus (FIV) infection. In the present study, we extended our previous observations with regard to FIV replication in CD4(+)CD25(+) and CD4(+)CD25(-) cells under different stimulation conditions. Both CD4(+)CD25(+) and CD4(+)CD25(-) cells remain latently infected in the absence of IL-2 or concanvalinA (ConA), respectively; harboring a replication competent provirus capable of reactivation several days post-infection. While CD4(+)CD25(+) cells require low levels of exogenous IL-2 and virus inputs for an efficient FIV replication, CD4(+)CD25(-) T cells can only be productively infected in the presence of either high concentrations of IL-2 or high virus titers, even in the absence of mitogenic stimulation. Interestingly, while high virus input activates CD4(+)CD25(-) cells to replicate FIV, it induces apoptosis in a high percentage of CD4(+)CD25(+) T cells. High IL-2 concentrations but not high virus inputs lead to surface upregulation of CD25 and significant cellular proliferation in CD4(+)CD25(-) cells. These results suggest that CD4(+)CD25(+) and CD4(+)CD25(-) T cells have different activation requirements which can be modulated by both viral and cytokine stimuli to reach threshold activation levels in order to harbor a productive FIV infection. This holds implications in vivo for CD4(+)CD25(+) and CD4(+)CD25(-) cells to serve as potential reservoirs of a productive and latent FIV infection.