Elevated circulating Th17 and follicular helper CD4+ T cells in patients with rheumatoid arthritis

It remains not fully elucidated the potential functions of Th17 cells and follicular helper T (Tfh) cells and secreting cytokines in the pathogenesis of rheumatoid arthritis (RA) and their association with disease activity. In this study, the frequencies of Th17 and Tfh cells were determined by flow cytometry, and the levels of interleukin (IL)‐17, IL‐21, and IL‐22 were measured by ELISA in RA patients with different disease activities. The dynamic changes of cell subsets were also detected in response to disease‐modify antirheumatic drugs (DMARDs) therapy. The percentages of CD3⁺CD4⁺IL‐17A⁺ (Th17) cells and CD3⁺CD4⁺CXCR5⁺ICOS^high (Tfh) cells, as well as the concentrations of IL‐17, IL‐21, and IL‐22 were significantly elevated in RA patients than those in healthy individuals. Furthermore, Tfh cells, IL‐21, and IL‐22 in the serum was positively correlated with the values of disease activity score. Concentrations of IL‐21 and IL‐22 in the serum were remarkably reduced following the DMARDs therapies. Our data suggested that Th17 cells, Tfh cells as well as the secreting cytokines may be involved in the pathogenesis of RA. The frequency of circulating Tfh cells and the productions of IL‐21 and IL‐22 were associated with the disease activity of RA patients, and might be potential therapeutic targets for treatment of RA.     

Effect of interleukin‐6 receptor blockade on the balance between regulatory T cells and T helper type 17 cells in rheumatoid arthritis patients

A new paradigm has emerged relating the pathogenesis of rheumatoid arthritis (RA), focused on the balance between T helper type 17 cells and regulatory T cells (T_regs). In humans, both subpopulations depend on transforming growth factor (TGF)‐β for their induction, but in the presence of inflammatory cytokines, such as interleukin (IL)‐6, the generation of Th17 is favoured. Tocilizumab is a therapeutic antibody targeting the IL‐6 receptor (IL‐6R), which has demonstrated encouraging results in RA. The aim of this study was to evaluate the effect of tocilizumab on Th1 cells, Th17 cells, IL‐17 and interferon (IFN)‐γ double secretors Th17/Th1 cells, and T_regs in RA patients. Eight RA patients received tocilizumab monthly for 24 weeks and blood samples were obtained every 8 weeks to study T cell populations by flow cytometry. The frequency of Th17 cells, Th1 cells and Th17/Th1 cells was evaluated in peripheral blood mononuclear cells (PBMCs) activated in vitro with a polyclonal stimulus. T_regs were identified by their expression of forkhead box protein 3 (FoxP3) and CD25 by direct staining of PBMCs. Although no changes were detected in the frequency of Th1 or Th17 cells, the percentages of peripheral T_regs increased after therapy. In addition, the infrequent Th17/Th1 subpopulation showed a significant increment in tocilizumab‐treated patients. In conclusion, tocilizumab was able to skew the balance between Th17 cells and T_regs towards a more protective status, which may contribute to the clinical improvement observed in RA patients.     

类风湿性关节炎患者外周血芳香烃受体表达与Th17细胞相关性研究

目的 检测类风湿性关节炎患者(RA)外周血单个核细胞芳香烃受体(AhR)的表达情况,分析其表达与Th17细胞相关性并初步探讨AhR在RA发病中的作用机制.方法 Ficoll密度梯度法分离75例RA患者(其中活动期RA患者40例,缓解期RA患者35例)及70例健康对照者外周血单个核细胞(PBMC),酶联免疫吸附实验(EUSA)检测细胞裂解上清中AhR蛋白表达.流式细胞术检测75例RA患者Th17细胞表达比例.分析RA患者AhR蛋白表达与Th17细胞比例及其他临床指标的相关性.结果 RA患者PBMC内AhR表达[(91.25±15.27) ng/L]高于健康对照组[(41.81 ±9.72) ng/L],差异有统计学意义(t=3.191,P＜0.01).活动期RA患者AhR表达与缓解期RA患者表达差异无统计学意义(P＞0.05).RA患者PBMC中AhR水平与Th17细胞表达呈正相关(r=0.361,P=0.0015).RA患者PBMC中AhR表达与血清IL-17水平呈正相关,与其他临床指标无相关性(r=0.324,P=0.006).结论 RA患者PBMC中AhR表达升高,且与Th17细胞和血清中IL-17水平呈正相关,推测RA中AhR可能正向调控Th17细胞分化,促进IL-17表达.     

类风湿关节炎患者外周血CD4+T细胞亚群的分析

目的 研究类风湿性关节炎(RA)患者不同时期外周血Treg和Th1、Th2、Th17细胞以及中性粒细胞上CD64的表达水平,及它们与RA的活动性指标和自身抗体的相关性.方法 采集78例RA患者和21例健康人外周静脉血,采用流式细胞术检测淋巴细胞亚群(Treg,Th1、Th2、Th17细胞)的变化.结果 RA的CD3+ CD4+T细胞和CD4+ CD25+T细胞增多,活动期RA组Treg比率高于缓解期RA组和健康对照组,缓解期RA组Th2细胞减少,RA中Th1,TH17细胞与健康对照组相比无统计学意义,Treg和Th1、Th2、Th17细胞与RA的活动性指标(ESR,CRP和PLT)均无关联.结论 CD4+T细胞亚群数量异常可能与RA疾病发展有关.     

Peripheral blood T helper type 17 frequency shows an inverse correlation with disease activity and magnetic resonance imaging‐based osteitis and erosions in disease‐modifying anti‐rheumatic drug‐ and steroid‐naive established rheumatoid arthritis

An increased expansion of T helper type 17 (Th17) cells in the synovium has been shown to play a key role in cartilage and bone destruction in rheumatoid arthritis (RA). Because the correlation of the peripheral blood helper T cell subsets and various inflammatory cytokines with the magnetic resonance imaging (MRI)‐based parameters have not been studied adequately to date, we sought to look for the same in this study. RA patients with disease duration less than 36 months, disease‐modifying anti‐rheumatic drugs (DMARDs) and steroid‐naive, were recruited. MRI of the dominant hand and wrist was performed using a 0·2 Tesla MRI machine. Peripheral blood Th1 and Th17 were enumerated by flow cytometry and serum interleukin (IL)‐6 and IL‐17 by enzyme‐linked immunosorbent assay (ELISA). Forty consecutive seropositive RA patients [33 females, mean disease duration 12·2 months, mean disease activity score (DAS)28 = 4·4] were included. MRI revealed erosions in 80% of these subjects. On subgroup analysis, prevalence of erosions (94 versus 68%) as well as mean erosion score (11·5 ± 18·9 versus 3·5 ± 6·0) were significantly higher in established RA (13–36 months' duration) compared to early RA (0–12 months). The median peripheral blood Th17 frequencies were significantly higher in patients (1·4%) compared to healthy controls (0·7%) and had a strong negative correlation with MRI parameters of erosion and osteitis as well as with DAS28 in the established RA subgroup. The frequency of peripheral blood Th17 subset was significantly expanded in established RA which correlated inversely with disease activity as well as MRI based erosions and osteitis.     

Increased autophagy in CD4+ T cells of rheumatoid arthritis patients results in T‐cell hyperactivation and apoptosis resistance

Rheumatoid arthritis (RA) is an autoimmune disease hallmarked by aberrant cellular homeostasis, resulting in hyperactive CD4⁺ T cells that are more resistant to apoptosis. Both hyperactivation and resistance to apoptosis may contribute to the pathogenicity of CD4⁺ T cells in the autoimmune process. A better knowledge of the mechanisms determining such impaired homeostasis could contribute significantly to both the understanding and the treatment of the disease. Here we investigated whether autophagy, is dysregulated in CD4⁺ T cells of RA patients, resulting in disturbed T‐cell homeostasis. We demonstrate that the rate of autophagy is significantly increased in CD4⁺ T cells from RA patients, and that increased autophagy is also a feature of in vitro activated CD4⁺ T cells. The increased apoptosis resistance observed in CD4⁺ T cells from RA patients was significantly reversed upon autophagy inhibition. These mechanisms may contribute to RA pathogenesis, as autophagy inhibition reduced both arthritis incidence and disease severity in a mouse collagen induced arthritis mouse model. Conversely, in Atg5^flox/flox‐CD4‐Cre⁺ mice, in which all T cells are autophagy deficient, T cells showed impaired activation and proliferation. These data provide novel insight into the pathogenesis of RA and underscore the relevance of autophagy as a promising therapeutic target.     

Metallothionein‐1 suppresses rheumatoid arthritis pathogenesis by shifting the Th17/Treg balance

It is now well accepted that an imbalance between the Th17 and regulatory T‐cell responses is closely associated with the development of rheumatoid arthritis (RA). However, the precise regulatory mechanism for the differentiation of Th17 and Treg in RA is not well characterized. The present study showed that metallothionein‐1 (MT‐1), which is a low molecular weight protein that is involved in the detoxification of heavy metals and scavenging of free radicals, was upregulated in RA. Furthermore, the synovial inflammation and pathologic symptoms in collagen‐induced arthritis and collagen antibody‐induced arthritis mice were significantly suppressed when MT‐1 was expressed intraarticularly. Further investigation revealed that MT‐1 inhibited the differentiation of Th17 cells but enhanced that of Treg cells. Furthermore, it markedly decreased both STAT3 and RAR‐related orphan receptor gamma t (RORγt) expression in vitro and in vivo. Collectively, our studies demonstrated that MT‐1 might manifest as a protein involved in immunosuppression of RA pathogenesis by shifting Th17/Treg balance and may prove to be a potential therapeutic target for RA autoimmune diseases.     

类风湿关节炎患者Th17细胞与调节性T细胞失衡的研究

目的观察类风湿性关节炎（RA）患者外周血Th17细胞与CD4^＋CD25^＋FoxP3^＋调节性T细胞（Treg）平衡状态与疾病的关系,分析Th17／Treg细胞免疫失衡在RA发病机制中的作用。方法采用流式细胞仪四色荧光抗体标记法分别对47例RA患者和39名健康志愿者（HVs）进行CD3、CD8、IL-17与CD4、CD25、F0xP3标记,测定Th17与调节性T细胞的比例变化及相关细胞因子IL-6、IL-23和IL-17水平。结果RA组患者外周血中,CD3^＋CD8^＋IL-17^＋T细胞占CD3^＋T淋巴细胞的百分比为（1．12±0．38）％,明显高于对照组（0．68±0．29）％（t=1．83,P〈0．05）;CD4’CD25’FoxP3^＋细胞占CD4^＋T淋巴细胞的百分比为（2．74±0．71）％,明显低于对照组（4．69±1．23）％（t=-2．94,P〈0．05）。相关细胞因子测定结果：IL-6水平在RA组为（13．5±3．7）ng／L,正常人为（4．6±0．9）ng／L（t=6．24,P〈0．01）;IL-23水平在RA组为（71±19）ng／L,正常人为（25±6）ng／L（t=14．37,P〈0．01）;IL-17水平在RA组为（122±33）ng／L,正常人为（37±9）ng／L（t=19．01,P〈0．01）;RA患者血清IL-6、IL-23和IL-17水平均明显升高。结论RA患者外周血Th17与CD4^＋CD25^＋FoxP3^＋调节性T细胞数量的异常可能是RA发病的重要因素,IL-6和IL-23的升高是引起这些改变的可能原因。     

Interleukin 17 contributes to the chronicity of inflammatory diseases such as rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory disease leading to joint destruction and bone resorption. The proinflammatory cytokine interleukin 17 (IL‐17), primarily produced by Th17 cells, has been shown to be involved in all stages of the disease and to be an important contributor of RA chronicity. Three major processes drive the IL‐17‐mediated chronicity. Several epigenetic events, enhanced in RA patients, lead to the increased production of IL‐17 by Th17 cells. IL‐17 then induces the production of several inflammatory mediators in the diseased synovium, which are further synergistically enhanced via combinations of IL‐17 with other cytokines. IL‐17 also promotes the survival of both the synoviocytes and inflammatory cells and promotes the maturation of these immune cells. This leads to an increased number of synoviocytes and inflammatory cells in the synovial fluid and in the synovium leading to the hyperplasia and exacerbated inflammation observed in joints of RA patients. Furthermore, these IL‐17‐driven events initiate several feedback‐loop mechanisms leading to increased expansion of Th17 cells and thereby increased production of IL‐17. In this review, we aim to depict a complete picture of the IL‐17‐driven vicious circle leading to RA chronicity and to pinpoint the key aspects that require further exploration.     

Immunodominant T‐cell epitopes of hnRNP‐A2 associated with disease activity in patients with rheumatoid arthritis

The heterogeneous nuclear ribonucleoprotein A2 (hnRNP‐A2) has been described as an important autoantigen in rheumatoid arthritis (RA) since it is targeted by autoantibodies, autoreactive T cells, and is aberrantly expressed in synovial cells in patients. To identify hnRNP‐A2‐specific T‐cell epitopes possibly associated with pathogenicity, we used an innovative approach. We first scanned 280 overlapping hnRNP‐A2 peptides for binding to the RA‐associated class II molecules HLA‐DR4 and HLA‐DR1, leading to a comprehensive selection of binders. The selected peptides were tested in IFN‐γ‐specific ELISPOT assay: PBMC from 18% of RA patients showed a significant IFN‐γ response to hnRNP‐A2 peptides, 15% to the overlapping sequences 117–133 and/or 120–133, whereas PBMC from healthy individuals tested negative. We measured proliferative responses to these two peptides in another cohort of patients with RA or osteoarthritis: positive responses were found in 28% of RA, but also in 11% of osteoarthritis patients and these responses could be blocked by anti‐MHC class II Ab. Remarkably, the presence of 117/120–133‐specific T cells was significantly associated with active disease in RA patients, and bone erosion appeared to be more common in T‐cell positive patients. These data suggest involvement of hnRNP‐A2 specific cellular autoimmune responses in RA pathogenesis.     

Lactobacillus rhamnosus reduces CD8+T cell mediated inflammation in patients with rheumatoid arthritis

BackgroundThe T cells, components of adaptive immunity participate in immune pathology of the autoimmune inflammatory disorder called rheumatoid arthritis (RA). The presence of TLRs on the surface of the CD8⁺ T cells and their ability to recognize bacterial moieties adds to the inflammatory burden in case of RA. It has been reported that the gut microbiome is necessary for the crucial shift in the balance between proinflammatory and anti-inflammatory cytokines. The altered gut microbiome and the presence of TLRs emphasizes on the microbiome driven inflammatory responses in case of RA.MethodsEighty-nine RA patients participated in this study. Clinical variations like disease duration, number of actively inflamed joints, number and type of bone deformities, CRP, RF, Anti-CCP, ESR, DAS 28 score were recorded for each patient. Co-culture of CD8⁺T cells and bacteria has been performed with proper culture condition. TLRs and inflammatory mediators’ expression level were checked by both qPCR and flow cytometry analysis.ResultsWe observed in the suppression of pro-inflammatory molecules like Granzyme B and IFNƳ and expression of TLR2 in CD8 + T cells upon treatment with Lactobacillus rhamnosus (L. rhamnosus). Moreover, L. rhamnosus activated CD8⁺T cells such that they could induce FOXP3 expression in CD4⁺T cells thereby skewing T cell population towards a regulatory phenotype. On the contrary, TLR4 engagement on CD8⁺T cell by Escherichia coli (E.coli) increased in inflammatory responses following ERK activation.ConclusionsThus, we conclude that L. rhamnosus can effectively suppress CD8⁺T cell mediated inflammation by a simultaneous decrease of Th1 cells that may potentiate better treatment modalities for RA.     

Surface expression of CD39 identifies an enriched Treg‐cell subset in the rheumatic joint,which does not suppress IL‐17A secretion

Treg cells are important for the maintenance of self‐tolerance and are implicated in autoimmunity. Despite enrichment of Treg cells in joints of rheumatoid arthritis (RA) patients, local inflammation persists. As expression of the ATP‐hydrolyzing enzymes CD39 and CD73 and the resulting anti‐inflammatory adenosine production have been implicated as an important mechanism of suppression, we characterized FOXP3⁺ Treg cells in blood and synovial fluid samples of RA patients in the context of CD39 and CD73 expression. Synovial FOXP3⁺ Treg cells displayed high expression levels of rate‐limiting CD39, whereas CD73 was diminished. FOXP3⁺CD39⁺ Treg cells were also abundant in synovial tissue. Furthermore, FOXP3⁺CD39⁺ Treg cells did not secrete the proinflammatory cytokines IFN‐γ and TNF after in vitro stimulation in contrast to FOXP3⁺CD39^? T cells. FOXP3⁺CD39⁺ Treg cells could be isolated by CD39 and CD25 coexpression, displayed a demethylated Treg‐specific demethylated region and coculture assays confirmed that CD25⁺CD39⁺ T cells have suppressive capacity, while their CD39^? counterparts do not. Overall, our data show that FOXP3⁺CD39⁺ Treg cells are enriched at the site of inflammation, do not produce proinflammatory cytokines, and are good suppressors of many effector T‐cell functions including production of IFN‐γ, TNF, and IL‐17F but do not limit IL‐17A secretion.     

类风湿关节炎患者外周血Tfh及Th9的变化及临床意义

目的 观察类风湿关节炎(RA)患者外周血中滤泡辅助性T细胞(Tfh)及T辅助细胞9(Th9)的变化,并与病情活动性及脏器受累等临床资料进行相关性分析,探讨Tfh及Th9在RA发病过程中可能的免疫学发病机制.方法 选择36例RA患者和22例健康对照.根据病情活动度不同将病例组分为病情高度活动组(22例)、病情中度活动组(14例),流式细胞仪检测RA和正常对照组外周血单个核细胞( PBMCs)中CD4-FITC、CXCR5-PE、ICOS-APC标记的CD4+ CXCR5+ ICOS+(Tfh)及CD8-FITC、CD3-APC、IL9-PE标记的CD3+CD8-IL-9+( Th9)比例.分析Tfh及Th9与RA患者的血沉(ESR)、C反应蛋白(CRP)、类风湿因子(RF)、关节压痛数、肿胀数及骨质破坏等指标的相关性;分析Tfh与Th9的关系.结果 RA患者的Tfh表达率明显高于对照组(Z=-6.082,P=0.000),RA患者Th9的表达率亦高于对照组(0.989±0.498 vs 0.213 ±0.084,t=13.063,P=0.000);RA重度活动组Tfh表达率亦高于中度活动患者的表达率(3.880±1.255 vs 2.678±1.022,t=2.990,P=0.005),且两组Tfh的表达率均高于对照组(P均＜0.01);RA重度活动患者Th9表达率高于中度患者(1.181±0.523 vs 0.686±0.254,t=4.043,P=0.000),且两组Th9的表达率亦均高于对照组(P均＜0.01); Tfh 细胞数与RA患者DAS28(r=0.571,P=0.000)、ESR(r=0.375,P=0.029)、CRP(r=0.357,P=0.032)、关节压痛数(r=0.598,P=0.000)、RF(r=0.421,P=0.023)及抗CCP滴度(r=0.421,P=0.023)正相关;与病程、晨僵、关节肿胀数、骨质破坏、心电图异常无相关性.Th9表达的百分率与RA患者的DAS28( r=0.461,P=0.005)、ESR(r=0.347,P=0.042)、CRP(r=0.384,P=0210)、关节压痛数(r=0.341,P=0.042)、关节肿胀数(r=0.347,P=0.038)及RF(r=0.379,P=0.025)正相关,与病程、晨僵时间、抗CCP滴度、心电图异常及骨质破坏无相关性;Tfh与Th9在外周血中的表达率呈正相关(r=0.727,P=0.000).结论 RA患者外周血Tfh及Th9的比例显著升高,且与疾病活动度及相关炎症指标明显相关,提示Tfn及Th9可能参与RA的发病及病情发展.     

Enhanced and persistent levels of interleukin (IL)‐17+CD4+ T cells and serum IL‐17 in patients with early inflammatory arthritis

Prognosis of patients with early inflammatory arthritis (EIA) is highly variable. The aim of this study was to compare, longitudinally and cross-sectionally, the levels of cytokine-expressing cells in peripheral blood (PB) from patients with EIA to those in established rheumatoid arthritis (RA) and healthy controls (HC). PB mononuclear cells from HC (n = 30), patients with EIA (n = 20) or RA (n = 38) were stimulated with phorbol myristate acetate (PMA)/ionomycin for 3 h, and stained for cell markers and cytokines. Serum cytokines and chemokines were measured by Luminex. Patients with EIA were reassessed at 6 and 12 months. The percentage of interleukin (IL)-17⁺interferon (IFN)-γ⁻CD4⁺ T cells [T helper type 17 (Th17)] was increased in RA and EIA versus HC. Serum IL-1β, IL-2, IL-4 IL-17 and macrophage inflammatory protein (MIP)-1α were increased in RA and EIA versus HC. IL-1Ra, IL-15 and IFN-α were increased in EIA versus HC. IL-6 and tumour necrosis factor (TNF)-α was increased in RA but not EIA versus HC. Disease activity scores in EIA patients improved over 12 months'' treatment. Th17 percentage at baseline was correlated with both rheumatoid factor (RF) titre and functional deficit at 12 months. Baseline levels of serum granulocyte–macrophage colony-stimulating factor (GM-CSF), IL-6 and IL-8 were correlated with Larsen score at 12 months. There were no significant changes in cytokine-expressing CD4⁺T cells over time, although the percentage of IL-6⁺ monocytes increased. IL-17⁺CD4⁺ T cells and serum IL-17 levels are increased in EIA. IL-6-expressing monocytes increase during the first year of disease, irrespective of disease-modifying anti-rheumatic drug (DMARD) therapy. We observed incomplete clinical responses, suggesting EIA patients need more intensive early therapy.     

类风湿性关节炎患者外周血TH17细胞测定

目的 探讨新的效应T细胞TH17在类风湿性关节炎(RA)患者外周血的分布及意义.方法 选取PHA或PMA+Ion作为刺激剂,建立流式细胞术胞内细胞因子染色的方法,应用该方法检测了35例活动期、30例稳定期RA患者及正常人外周血TH17和TH1细胞百分率.结果 PlVIA+Ion联合刺激的效果优于PHA.RA患者及正常人T细胞经PMA+Ion刺激后,CD3+CD8-T细胞IL-17表达水平较相应未刺激组显著增加(P<0.05).而不论是否加刺激剂,活动期RA患者外周血CD3+CD8-IL-17+细胞明显多于稳定期,二者均多于正常对照组(P<0.05).RA患者外周血TH1细胞呈现与T<,H>17细胞类似的分布特点.结论 活动期RA患者外周血存在TH17细胞的分布异常,T1H17细胞可作为评价RA患者细胞免疫功能状态的新指标.     

Hydroxychloroquine decreases Th17-related cytokines in systemic lupus erythematosus and rheumatoid arthritis patients

OBJECTIVES:

Hydroxychloroquine is an antimalarial agent that has been used in systemic lupus erythematosus and rheumatoid arthritis treatment for many years. Recently, novel mechanisms of action have been proposed, thereby broadening the therapeutic perspective of this medication. The purpose of this study was to evaluate the immunomodulatory activity of hydroxychloroquine in T helper 17 (Th17) cytokines in healthy individuals and patients.

METHODS:

Eighteen female patients with systemic lupus erythematosus (mean age 39.0±12.9 years) and 13 female patients with rheumatoid arthritis (mean age 51.5±7.7 years) were recruited from Universidade Federal de Pernambuco-Brazil. The patients were included after fulfilling four classification criteria for systemic lupus erythematosus or rheumatoid arthritis from the American College of Rheumatology. After being stimulated with phorbol 12-myristate 13-acetate and ionomycin in the absence or presence of different concentrations of hydroxychloroquine, the interleukin 6, 17 and 22 levels were quantified with an enzyme-linked immunosorbent assay in culture supernatants of peripheral blood mononuclear cells from healthy individuals and patients.

RESULTS:

We demonstrated that in peripheral blood mononuclear cells from healthy volunteers and in systemic lupus erythematosus and rheumatoid arthritis patients, there was a significant reduction in the IL-6, IL-17 and IL-22 supernatant levels after adding hydroxychloroquine.

CONCLUSIONS

Our in vitro results demonstrated that hydroxychloroquine inhibits IL-6, IL-17 and IL-22 production and contributes to a better understanding of the mechanism of action of this medication.     

Th细胞在类风湿关节炎发病作用的研究进展

T细胞功能紊乱,尤其是辅助性CD4+T细胞异常活化,在类风湿关节炎(rheumatoid ar thritis,RA)的发生发展中处于中心环节,CD4+T细胞亚群Th1/Th2细胞及Th17/Treg细胞之间的失衡可能是RA发病的最直接和最重要的因素。Th细胞相关细胞因子通过作用于多种细胞并相互调节形成一个复杂的网络,Th1和Th17细胞通过产生炎性细胞因子IFN、TNF-α、IL-2、IL-1、IL-17等造成了滑膜炎的发生,Th2和Treg细胞通过直接接触或分泌细胞因子IL-4、IL-10等参与抗炎效应。本文旨在阐述Th细胞及相关细胞因子的促炎和抗炎平衡在RA发生发展中所起的关键作用。     

Activating NK‐cell receptors co‐stimulate CD4+CD28− T cells in patients with rheumatoid arthritis

Effector T‐cell responses can be modulated by competing positive or negative signals transduced by NK‐cell receptors (NKR). In the CD4⁺ T‐cell population, the expression of NKR is primarily found in the CD4⁺CD28⁻ T‐cell subset, also known as CD28^null T cells. These T cells are frequently found in rheumatoid arthritis (RA) and other inflammatory disorders, suggesting that signaling through NKR may play a role in the autoimmune reaction. Here we aimed to dissect the phenotype and function of NKR‐expressing CD4⁺CD28⁻ T cells in patients with RA. By analyzing a broad array of NKR on CD4⁺CD28⁻ T cells we found a significant expression of the co‐activating receptors 2B4 (CD244), DNAM‐1 (CD226), and CRACC. Pair‐wise ligations of 2B4 with DNAM‐1 and/or NKG2D lead to increased effector functions of primary CD4⁺CD28⁻ T cells to suboptimal levels of anti‐CD3 stimulation. Using multi‐parameter flow cytometry, we demonstrate that such co‐ligation led to an increased magnitude in overall responsiveness without changing qualitative aspects of the response. Altogether these results demonstrate a pattern of additive effects in NKR‐mediated functional modulation of CD4⁺CD28⁻ T cells in RA. This may have consequences for the inflammatory responses imposed by these cells, thus influencing disease manifestations.     

Functional TLR9 modulates bone marrow B cells from rheumatoid arthritis patients

TLR9 recognizes unmethylated CpG‐rich, pathogen‐derived DNA sequences and represents the component of the innate immune system that heavily influences adaptive immunity and may contribute to the immunological disturbances in rheumatoid arthritis (RA). Accumulating data indicate that BM of RA patients participates in the pathogenesis of this disease as a site of proinflammatory cytokines overproduction and lymphocytes activation. Here, we investigated the functionality of TLR9 and its role in the modulation of RA BM B‐cell functions. We report that BM B cells isolated from RA patients express TLR9 at the mRNA and protein levels acquired at the stage of preB/immature B‐cell maturation. Stimulation of BM CD20⁺ B cells by CpG‐containing oligodeoxynucleotide‐enhanced expression of activation markers (CD86 and CD54) triggered IL‐6 and TNF‐α secretion and cell proliferation. Significantly higher levels of eubacterial DNA encoding 16S‐rRNA were found in BM samples from RA than osteoarthritis patients. Moreover, RA BM B cells exerted higher expression of CD86 than their osteoarthritis counterparts, suggesting their in situ activation via TLR9. Thus, our data indicate that TLR9 may participate in direct activation and proliferation of B cells in BM, and therefore could play a role in the pathogenesis of RA.