Deviated balance between Th1 and Th17 cells exacerbates acute graft-versus-host disease in mice

BackgroundTh1/Th17 imbalance had been indicated to mediate several kinds of inflammatory diseases. We deduce that Th1/Th17 imbalance might also contribute to the pathogenesis of acute graft-versus-host disease (GVHD). This study is to investigate the relation between Th1/Th17 imbalance and acute GVHD.MethodsWe applied a murine GVHD model of C57BL/6 (H-2^b) donor to BALB/c (H-2^d) recipient by treating the recipients with low dose of halofuginone (HF), which is competent in selectively inhibiting Th17 differentiation and facilitating Th1 differentiation. Recipient mice were monitored for survival rate, body weight change, clinical symptoms and pathological evidence of acute GVHD. We also measured the proportions of Th1 and Th17 cells in circulation and expression levels of IFN-γ and IL-17A in tissues involved in GVHD.ResultsFirstly, we confirm the existence of Th1/Th17 imbalance in acute GVHD and Th1/Th17 imbalance positively correlates with severity of acute GVHD. Secondly, low dose of HF augments Th1/Th17 imbalance by driving the Th1/Th17 balance to a Th1-dominant reaction. Finally, augmented Th1/Th17 imbalance leads to aggravated systemic GVHD. An increased Th1-type reaction results in aggravated hepatic and intestinal GVHD, and inhibiting Th17 differentiation is sufficient to alleviate pulmonic impairment.ConclusionOur study is indicative for a critical role of Th1/Th17 imbalance in the pathogenesis of murine GVHD.     

Ursolic acid inhibits Th17 cell differentiation via STAT3/RORγt pathway and suppresses Schwann cell-mediated Th17 cell migration by reducing CXCL9/10 expression

Th17 cells represent important immune cells. Ursolic acid (UA) can regulate immune cell activities. This study was aimed to explore the effects of UA on Th17 cell differentiation and Schwann cell(SCs)-mediated migration and the potential mechanism. Naïve CD4⁺ T cells were isolated from rat peripheral blood, induced for Th17 cell differentiation, and treated with UA. The proportion of Th17 cells was detected by flow cytometry assay. SCs were co-cultured with Th17 cells. Th17 cell migration was detected by Transwell assay. The molecule expression was determined by Western blot and qRT-PCR. UA inhibited the Th17 cell differentiation and suppressed the STAT3/RORγt pathway. STAT3 overexpression up-regulated p-STAT3 and RORγt expression and promoted Th17 cell differentiation under the UA treatment. In LPS- and IFN-γ-stimulated-SCs, UA suppressed the expression of chemokines CXCL9/10, but had no significant effect of CCL20 expression. The expression CXCL9/10 receptor CXCR3 was higher in Th17 cells than that in Treg cells, while the expression CCL20 receptor CCR6 was lower in Th17 cells than that in Treg cells. UA, anti-CXCR3, and anti-CCR6 treatment inhibited SCs-mediated Th17 cell migration, and anti-CXCR3 exerted stronger inhibitory effect than Anti-CCR6. UA inhibited Th17 cell differentiation through STAT3/RORγt pathway and suppressed Th17 cell migration through down-regulating CXCL9/10 expression in SCs.     

Th17及Th1相关细胞因子与支气管哮喘的关系研究

目的:分析外周血Th17、Th1及相关细胞因子表达水平和支气管哮喘(bronchial asthma,BA)发生、发展的相关性研究。方法:回顾选取我院收治的BA病例57份,称作BA组,另选取呼吸系统正常的病例55例为对照组,检测两组入选者的外周血IL-2、TNF-α、Th17、IL-6、Th1指标表达差异,并进行多因素回归分析。结果:BA组Th17(0.62±1.67)%、Th1(1.45±0.48)%及Th1/Th17(2.33±1.28)均显著低于对照组(P均0.05);BA组TNF-α(27.46±8.12)pg/mL、IL-6(11.69±2.14)pg/mL表达量显著高于对照组,IL-2(2.58±3.89)pg/mL、IFN-γ(3.74±6.15)pg/mL含量均显著低于对照组(P均0.05);经Logistic回归分析,TNF-α、IL-6、IFN-γ、Th1/Th17、IL-2均和BA有密切相关性(P均0.05)。结论:IL-2、IFN-γ、Th1/Th17、TNF-α、IL-6表达水平均与BA有密切关联,可能是参与BA发病的主要原因,及早进行Th17、Th1及相关细胞因子检查有助于明确病情。     

Th17细胞和Treg细胞的细胞因子调节网络

Th17细胞和Treg细胞是CD4+T细胞的新亚群,在分化发育、功能发挥的过程中受到Th1型、Th2型效应细胞以及自身分泌产生细胞因子的调节,参与自身免疫病、感染、肿瘤等疾病的发生发展。通过对Th17和Treg分化发育、和功能发挥过程中的关键调节因子进行阻断或加强,可以上调或下调Th17和Treg在疾病中的表达,以用于疾病的预防和诊治。     

Cyclosporin A inhibits the production of IL-17 by memory Th17 cells from healthy individuals and patients with rheumatoid arthritis

Recent evidence from several studies indicated that IL-17-producing Th17 cells can represent the key effector cells in the induction and development of autoimmune disorders. Cyclosporine A (CsA) is a commonly used immunosuppressant to treat lots of autoimmune diseases including rheumatoid arthritis (RA). Here, we demonstrated that PBMCs and purified CD4⁺ T cells from healthy individuals and patients with RA could be induced to produce large amounts of IL-17 after stimulation with anti-CD3 plus anti-CD28 mAbs. Phenotypic analysis indicated that the majority of IL-17-producing cells were Th17 cells with memory phenotype. The addition of CsA into cell cultures significantly inhibited the IL-17 production by Th17 cells at protein and at mRNA levels. Compared to the PBMCs from normal individuals, PBMCs from the patients with RA produced higher levels of IL-17 that was also significantly inhibited by CsA both at protein and at mRNA levels. The mechanism might be the effect of CsA on the T cells activation because the expression of CD69 and CD25 molecules on T cells was markedly reduced in the presence of CsA. Taken together, these results demonstrated that CsA suppressed the IL-17 production and inhibited the Th17 cells differentiation from both healthy individuals and patients with RA.     

Th17细胞和Treg细胞与动脉粥样硬化

动脉粥样硬化从脂质条纹的形成到更复杂的病变和斑块破裂的进程是由多种不同类型的细胞和细胞因子网络共同参与作用的,其中最主要的是Th17细胞和Treg细胞及它们分泌的细胞因子。大量研究显示,Th17细胞对动脉粥样硬化的作用仍存在争议,但大部分研究仍认为其具有促动脉粥样硬化的作用。Treg细胞具有抗动脉粥样硬化的作用,Th17／Treg平衡对动脉粥样硬化的发生和发展具有重要的调节作用。本文将对Th17细胞、Treg细胞的生物学特性以及Th17细胞、Treg细胞和Th17／Treg平衡对动脉粥样硬化影响的最新研究进展做一综述。     

Decreased expression of microRNA‐21 correlates with the imbalance of Th17 and Treg cells in patients with rheumatoid arthritis

The imbalance of Th17/Treg cell populations has been suggested to be involved in the regulation of rheumatoid arthritis (RA) pathogenesis; however, the mechanism behind this phenomenon remains unclear. Recent studies have shown how microRNAs (miRNAs) are important regulators of immune responses and are involved in the development of a variety of inflammatory diseases, including RA. In this study, we demonstrated that the frequencies of CD3⁺CD4⁺IL‐17⁺Th17 cells were significantly higher, and CD4⁺CD25⁺FOXP3⁺ Treg cells significantly lower in peripheral blood mononuclear cells from RA patients. Detection of cytokines from RA patients revealed an elevated panel of pro‐inflammatory cytokines, including IL‐17, IL‐6, IL‐1β, TNF‐α and IL‐22, which carry the inflammatory signature of RA and are crucial in the differentiation and maintenance of pathogenic Th17 cells and dysfunction of Treg cells. However, the level of miR‐21 was significantly lower in RA patients, accompanied by the increase in STAT3 expression and activation, and decrease in STAT5/pSTAT5 protein and Foxp3 mRNA levels. Furthermore, lipopolysaccharide stimulation up‐regulated miR‐21 expression from healthy controls, but down‐regulated miR‐21 expression from RA patients. Therefore, we speculate that miR‐21 may be part of a negative feedback loop in the normal setting. However, miR‐21 levels decrease significantly in RA patients, suggesting that this feedback loop is dysregulated and may contribute to the imbalance of Th17 and Treg cells. MiR‐21 may thus serve as a novel regulator in T‐cell differentiation and homoeostasis, and provides a new therapeutic target for the treatment of RA.     

Th17细胞及白细胞介素-17在肝移植急性排斥反应中的意义

目的探讨Th17细胞及相关因子白细胞介素-17（IL-17）在肝移植急性排斥反应中的变化及意义。方法收集2011年1月至2012年12月大连医科大学附属第二医院肝移植手术患者28例,根据移植肝组织穿刺活检病理诊断结果将肝移植的28例患者分为急性排异反应组6例和无排斥反应稳定组22例,15名健康体检者作为对照组。急性排斥组及稳定组在移植术后3 d和7 d,行肝穿刺活检病理检查;同时检测受检者外周血Th17细胞,受检者血清中IL-17水平。结果移植肝穿刺活检病理诊断显示急性排斥组随着移植时间延长,排斥反应逐渐增强。肝组织出现典型的细胞免疫性病理损伤,术后7 d肝脏汇管区、肝实质、小静脉壁、胆管上皮内及小叶间胆管被大量的淋巴细胞及嗜中性粒细胞包绕及浸润,胆管上皮细胞内空泡形成、上皮细胞凋亡。病理改变明显比术后3 d严重;急性排斥组患者术后3 d和7 d外周血Th17细胞比例及血清中IL-17含量较稳定组和对照组均明显增多（P〈0.05）,且Th17细胞及IL-17在术后急性排斥期7 d值均明显高于3 d（P〈0.05）。结论 Th17细胞及IL-17在肝移植急性排斥反应的发生、发展中可能起着促进作用,外周血Th17细胞及IL-17的检测有可能成为肝移植急性排斥反应的早期诊断指标。     

A Marine Carotenoid,Fucoxanthin, Induces Regulatory T Cells and Inhibits Th17 Cell Differentiation in Vitro

Fucoxanthin is a non-provitamin A carotenoid contained in brown seaweeds. We found that it suppressed interleukin-17 secretion from CD4⁺ T cells under IL-17-producing T (Th17) cell development conditions. By evaluating T cell differentiation in vitro, fucoxanthin and its metabolite fucoxanthinol inhibited T cell differentiation into Th17 cells. This suggests that fucoxanthin can improve inflammatory diseases due to Th17 cells.     

The effect of pro-inflammatory cytokines on immunophenotype,differentiation capacity and immunomodulatory functions of human mesenchymal stem cells

Mesenchymal stem cells (MSCs), as cells with potential clinical utilities, have demonstrated preferential incorporation into inflammation sites. Immunophenotype and immunomodulatory functions of MSCs could alter by inflamed-microenvironments due to the local pro-inflammatory cytokine milieu. A major cellular mediator with specific function in promoting inflammation and pathogenicity of autoimmunity are IL-17-producing T helper 17 (Th17) cells that polarize in inflamed sites in the presence of pro-inflammatory cytokines such as Interleukin-1β (IL-1β), IL-6 and IL-23. Since MSCs are promising candidate for cell-based therapeutic strategies in inflammatory and autoimmune diseases, Th17 cell polarizing factors may alter MSCs phenotype and function. In this study, human bone-marrow-derived MSCs (BM-MSC) and adipose tissue-derived MSCs (AD-MSC) were cultured with or without IL-1β, IL-6 and IL-23 as pro-inflammatory cytokines. The surface markers and their differentiation capacity were measured in cytokine-untreated and cytokine-treated MSCs. MSCs-mediated immunomodulation was analyzed by their regulatory effects on mixed lymphocyte reaction (MLR) and the level of IL-10, TGF-β, IL-4, IFN-γ and TNF-α production as immunomodulatory cytokines. Pro-inflammatory cytokines showed no effect on MSCs morphology, immunophenotype and co-stimulatory molecules except up-regulation of CD45. Adipogenic and osteogenic differentiation capacity increased in CD45+ MSCs. Moreover, cytokine-treated MSCs preserved the suppressive ability of allogeneic T cell proliferation and produced higher level of TGF-β and lower level of IL-4. We concluded pro-inflammatory cytokines up-regulate the efficacy of MSCs in cell-based therapy of degenerative, inflammatory and autoimmune disorders.     

Synergistic and additive interactions between receptor signaling networks drive the regulatory T cell versus T helper 17 cell fate choice

CD4+ T cells differentiate into subsets that promote immunity or minimize damage to the host. T helper 17 cells (Th17) are effector cells that function in inflammatory responses. T regulatory cells (Tregs) maintain tolerance and prevent autoimmunity by secreting immunosuppressive cytokines and expressing check point receptors. While the functions of Th17 and Treg cells are different, both cell fate trajectories require T cell receptor (TCR) and TGF-β receptor (TGF-βR) signals, and Th17 polarization requires an additional IL-6 receptor (IL-6R) signal. Utilizing high-resolution phosphoproteomics, we identified that both synergistic and additive interactions between TCR, TGF-βR, and IL-6R shape kinase signaling networks to differentially regulate key pathways during the early phase of Treg versus Th17 induction. Quantitative biochemical analysis revealed that CD4+ T cells integrate receptor signals via SMAD3, which is a mediator of TGF-βR signaling. Treg induction potentiates the formation of the canonical SMAD3/4 trimer to activate a negative feedback loop through kinases PKA and CSK to suppress TCR signaling, phosphatidylinositol metabolism, and mTOR signaling. IL-6R signaling activates STAT3 to bind SMAD3 and block formation of the SMAD3/4 trimer during the early phase of Th17 induction, which leads to elevated TCR and PI3K signaling. These data provide a biochemical mechanism by which CD4+ T cells integrate TCR, TGF-β, and IL-6 signals via generation of alternate SMAD3 complexes that control the development of early signaling networks to potentiate the choice of Treg versus Th17 cell fate.     

A critical role of LFA-1 in the development of Th17 cells and induction of experimental autoimmune encephalomyelytis

Snu13p is a Saccharomyces cerevisiae protein essential for pre-messenger RNA splicing and pre-ribosomal RNA processing. Snu13p binds U4 snRNA of the spliceosome and box C/D snoRNAs of the pre-ribosomal RNA processing machinery to induce assembly of each ribonucleoprotein complex. Here, we present structural and biochemical analysis of Snu13p. The crystal structure of Snu13p reveals a region of the protein which could be important for protein interaction during ribonucleoprotein assembly. Using the structure of Snu13p we have designed the first temperature-sensitive mutants in Snu13p, L67W and I102A. Wild-type and mutant Snu13p proteins were assayed for binding to U4 snRNA and U3 snoRNA. Both temperature-sensitive mutants displayed significantly reduced RNA binding compared to wild-type protein. As the temperature-sensitive mutations are not in the known RNA binding region of Snu13p this indicates that these mutants indirectly influence the RNA binding properties of Snu13p. This work provides insight into Snu13p function during ribonucleoprotein assembly.     

食物过敏患儿肠道菌群特征及其与外周血Treg/Th17的相关性

分析食物过敏患儿肠道菌群分布与外周血免疫细胞Treg/Th17的关系。

选择2020年4月至2022年5月本院儿科收治的86例食物过敏患儿作为观察组,另选择同期80例健康儿童作为健康对照组。采集两组儿童新鲜粪便和外周血样本,分别测定肠道菌群数量以及外周血Treg/Th17细胞、血清相关细胞因子水平,并经Pearson相关性分析肠道菌群与外周血Treg/Th17的相关性。

观察组患儿肠道内乳杆菌、双歧杆菌数量均低于健康对照组（均P＜0.05）;观察组患儿外周血内Treg细胞水平、Treg/Th17比值均低于健康对照组,但Th17细胞水平高于健康对照组（均P＜0.05）;观察组患儿的血清白细胞介素-17（interleukin-17,IL-17）水平高于健康对照组,血清转化生长因子-β1（transforming growth factor-β1,TGF-β1）指标低于健康对照组（均P＜0.05）;Pearson相关性分析结果显示,乳杆菌、双歧杆菌与外周血Treg细胞、TGF-β1水平均呈正相关,而与外周血Th17细胞、IL-17水平均呈负相关（均P＜0.05）。

食物过敏患儿伴显著的肠道菌群紊乱与免疫功能异常状况,肠道内乳杆菌和双歧杆菌水平以及外周血Treg细胞、TGF-β1表达减少,外周血Th17细胞、IL-17表达增多。临床应改善患儿肠道微生态环境,调控肠道菌群结构,促进肠道菌群分布平衡恢复。

     

TGF-β is necessary for induction of IL-23R and Th17 differentiation by IL-6 and IL-23

TGF-β and IL-6 induce Th17 differentiation, and IL-23 is required for expansion and maintenance of Th17 cells. Recently, it was shown that IL-6 up-regulates IL-23R mRNA in naive CD4⁺ T cells and therefore IL-6 and IL-23 synergistically promote Th17 differentiation. However, the molecular mechanism whereby IL-6 and IL-23 induce Th17 differentiation and the relevance to TGF-β remain unknown. Here, we found that IL-6 up-regulated IL-23R mRNA expression, and IL-6 and IL-23 synergistically augmented its protein expression. The combination induced Th17 differentiation, and TGF-β1 further enhanced it. IL-6 augmented endogenous TGF-β1 mRNA expression, whereas the amount of TGF-β produced was not enough to induce Th17 differentiation by IL-6 alone. However, unexpectedly, the up-regulation of IL-23R and induction of Th17 differentiation by IL-6 and IL-23 were almost completely inhibited by anti-TGF-β. These results suggest that the induction of IL-23R and Th17 differentiation by IL-6 and IL-23 is mediated through endogenously produced TGF-β.     

Th17细胞及其在器官移植排斥反应中的作用

最近发现的辅助T细胞17（T helper cell 17,Th-17）是不同于辅助T细胞1型（Thelpercell1,Th-1）,辅助T细胞2型（Thelpercell2,Th-2）及调节性T细胞（regulatory T cell,Treg）的T细胞亚群,有其独立的分化和发育调节,且互相影响。它由初始T细胞在转化生长因子B（transforming growth factor B,TGF—B）与白细胞介素6（interleukin6,IL-6）、白细胞介素23（interleukin23,1L23）联合作用及转录因子维甲酸相关孤儿素受体γt（retinoic acid related orphan nuclear receptorm,ROR-γt）的协同诱导精细的调节下分化而来。其主要分泌的生物效应分子白细胞介素17（Interleukin17,IL-17）是一种促炎性反应细胞因子,在免疫和造血系统等发挥重要的作用。而器官移植排斥反应的本质就是炎性反应。因此深入研究Th-17细胞分化及其相关生物效应,有助认识其在器官移植排斥中的病理机制,也为治疗移植排斥反应提供新的靶点和途径。     

不同RF型类风湿性关节炎患者Th17相关细胞因子表达研究

目的:探讨类风湿因子阳性与阴性类风湿关节炎(rheumatoid arthritis,RA)患者外周血中辅助T细胞(Th17)及相关细胞因子白介素17(interleukin,IL-17),白介素6(interleukin,IL-6)表达的差异。方法:收集RA患者51例,根据RF测定分为RF+、RF-组,健康查体者(对照组)20例,采用流式细胞术检测受检者外周血单个核细胞(PBMC)的Th17细胞的百分率;以酶联免疫吸附法(ELISA)检测受检者血浆中IL-17,IL-6的水平。结果:RA患者CD4+IL-17+T细胞,IL-17、IL-6水平均高于对照组,RF因子阳性与阴性RA患者之间CD4+IL-17+T细胞,IL-17、IL-6表达水平均存在差异有统计学意义。结论:在RA中不同RF型免疫反应和炎症表达的不同,可能与Th17及相关细胞因子表达差异有关。     

Role of CD69 in the pathogenesis of elastase-induced pulmonary inflammation and emphysema

Cluster of differentiation 69 (CD69), known as an early activation marker of lymphocytes, has been demonstrated to regulate inflammatory events in various disease models. Although the increased number of CD69-expressed T lymphocytes in the lungs of patients with chronic obstructive pulmonary disease (COPD) has been reported, a functional role of CD69 in the pathogenesis of COPD remains unknown. To address to this question, CD69-deficient (CD69KO) mice and wild-type (WT) mice were subjected to a mouse model of porcine pancreatic elastase (PPE)-induced pulmonary inflammation and emphysema. In the two genotypes, PPE increased counts of macrophages, neutrophils and lymphocytes in bronchoalveolar lavage fluid (BALF) and induced emphysematous changes in the lung, whereas those two pathological signs were significantly enhanced in CD69KO mice compared to WT mice. Moreover, the PPE-induced levels of IL-17 and IL-6 in BALF were significantly higher in CD69KO mice than in WT mice at the acute inflammatory phase. Immunofluorescent studies showed that IL-17 and IL-6 were predominantly expressed in CD4⁺ and γδ T cells and macrophages, respectively. Concomitant administration of IL-17- and IL-6-neutralizing antibodies significantly attenuated the PPE-induced emphysematous changes in the two genotypes. These findings suggest that CD69 negatively regulates the development of PPE-induced emphysema in part at least through modulating function of IL-17-producing T cells.