Aryl hydrocarbon receptor (AhR) is a key transcription factor that modulates the differentiation of T helper 17 (Th17) cells. How AhR is regulated at the post-translational level in Th17 cells remains largely unclear. Here, we identify USP21 as a newly defined deubiquitinase of AhR. We demonstrate that USP21 interacts with and stabilizes AhR by removing the K48-linked polyubiquitin chains from AhR. Interestingly, USP21 inhibits the transcriptional activity of AhR in a deubiquitinating-dependent manner. USP21 deubiquitinates AhR at the K432 residue, and the maintenance of ubiquitination on this site is required for the intact transcriptional activity of AhR. Moreover, the deficiency of USP21 promotes the differentiation of Th17 cells both in vitro and in vivo. Consistently, adoptive transfer of USP21-deficient naïve CD4+ T cells elicits more severe colitis in Rag1-/- recipients. Therefore, our study reveals a novel mechanism in which USP21 deubiquitinates AhR and negatively regulates the differentiation of Th17 cells.

IL-10 is critical for Foxp3(+) regulatory T cell (Tregs)-mediated immune suppression, but how to efficiently upregulate IL-10 production in Tregs remains unclear. In this article, we show that human IL-10(+) FOXP3(+)-induced regulatory T cell (iTreg) generation can be dramatically promoted by inhibiting GSK3 activity. IL-10+ FOXP3(+) iTregs induced by GSK3 inhibition exhibit classical features of immune-suppressive T cells. We further demonstrate that IL-10(+) iTregs exhibit enhanced suppressive function in both IL-10-dependent and -independent manners. The enhanced suppressive function of IL-10(+) Tregs is not due to a single factor such as IL-10, although IL-10 may mediate this enhanced suppressive function to some extent. Mechanistically, the increased transcriptional activity of IL-10 promoter and the enhanced expression of C-Maf and BLIMP1 coordinately facilitate IL-10 expression in human iTregs under GSK3 inhibition. Our study provides a new strategy to generate human immune-suppressive IL-10(+) FOXP3(+) Tregs for immunotherapies.

Both NLRP3 inflammasome and Th17 cells play important roles in the pathogenesis of systemic lupus erythematosus (SLE). Here we tried to investigate whether leptin promotes the differentiation of Th17 cells from lupus mice by activating the NLRP3 inflammasome. Th17 cells induced from MRL/Mp-Fas lpr mice splenocytes under Th17 polarizing condition were treated with leptin at scalar doses during the last 18 h of culture. The mRNA levels of IL-17A, IL-17F, RORγt, IL-1β, IL-18, NLRP3, ASC, and IL-1R1 were detected by quantitative PCR. IL-17A, IL-17F, IL-1β, and IL-18 were tested by ELISA, while the activity of caspase-1 and number of Th17 cells were counted by flow cytometry before/after inhibition of the NLRP3 inflammasome. We found that leptin pushed up the expression of IL-17A, IL-17F, NLRP3, and IL-1β and increased the number of Th17 cells in lupus mice, while the expression of IL-17A, RORγt, and IL-1β and the number of Th17 cells were decreased after inhibition of the NLRP3 inflammasome. Leptin promoted the differentiation of Th17 cells from lupus mice by activating the NLRP3 inflammasome.

Gouty arthritis is an inflammatory disease that is triggered by abnormal uric acid metabolism, which is usually attributed to obesity, a risk factor of hyperuricemia and gout attack. A high level of leptin in plasma is a marker of individuals with obesity. Population studies show that leptin promotes obesity-related arthritis, such as osteoarthritis, but it is unknown whether leptin contributes to gouty arthritis, another form of obesity-related arthritis. Our present study showed that the levels of leptin and leptin receptor in patients with active gouty arthritis were elevated. Leptin facilitates the stimulation of human synoviocytes, mouse peritoneal macrophages, and HL-60 cells induced by monosodium urate, leading to higher levels of acute gout-related proinflammatory factors. Leptin obviously exacerbates the inflammation of monosodium urate-induced acute gouty arthritis in wild-type mice, whereas that in leptin-deficient C57BL6/J(ob/ob) mice is markedly alleviated. The proinflammatory effect of leptin in acute gouty arthritis is partly mediated by mTORC1 signaling pathway. Our study reveals that leptin may serve as a novel prevention and treatment target in acute gouty arthritis.

OBJECTIVES:Which helper CD4+ T cell subset contributes to autoantibodies generation and severity of end-organ involvement in lupus patients remains to be explored. Our research aims to investigate the roles of circulating Tfh (cTfh) cell subsets and corresponding CXCR5- Th cells in lupus patients and their correlation with SLE disease activity index 2000 (SLEDAI). METHODS:Peripheral blood mononuclear cells (PBMCs) were isolated from blood of systemic lupus erythematosus (SLE) patients as well as healthy donors. The proportion of Th cell subsets classified from cell surface markers (CD45RO, CXCR5, CXCR3, CCR6, PD-1, ICOS, and CCR7) is detected by flow cytometry. RESULTS:We found no difference in the frequency of CD45RO+CXCR5+CD4+ T cells between SLE patients and health controls. As previously reported, SLE patients showed an increase in the percentage of CXCR5+PD-1+, CXCR5+ICOS+PD-1+ and CXCR5+CCR7loPD-1hi cTfh subset, however, none of these populations had correlation with SLEDAI. Therefore, we further investigated the CXCR5- subsets, and surprisingly we found that the frequency of CXCR3-PD-1+ subset was correlated with SLEDAI, ds-DNA IgG, anti-nucleosome antibody, C3, and C4 independent of CXCR5. Consistently, CXCR3-PD-1+CD45RO+CD4+T cells expressed factors associated with B-cell-help for the autoantibody production. CONCLUSION:CXCR3-PD-1+CD4+T cells are a sensitive indicator to assess SLE disease activity and might contribute B cell help and the generation of autoantibodies in patients.

Background: RORγt is required for Th17 cell function and differentiation. Results: TRAF5 stabilizes RORγt by ubiquitination and augments RORγt-mediated transcriptional expression of IL-17A. Conclusion: TRAF5 is a positive regulator for RORγt. Significance: TRAF5 could be a novel target for modulating RORγt-mediated inflammation and autoimmune diseases, including systemic lupus erythematosus. Retinoid-related orphan nuclear receptor γt (RORγt) is a key transcription factor for the development and function of Th17 cells. In this study, we show that tumor necrosis factor receptor-associated factor 5 (TRAF5), known as an E3 ubiquitin protein ligase and signal transducer, interacts with and ubiquitinates RORγt via Lys-63-linked polyubiquitination. TRAF5 stabilizes the RORγt protein level depending on its RING finger domain. Depletion of TRAF5 in Th17 cells destabilizes RORγt protein and down-regulates Th17-related genes, including IL-17A, an inflammatory cytokine involved in pathogenic mechanisms of several autoimmune diseases such as systemic lupus erythematosus. Moreover, up-regulation of the TRAF5 mRNA level was found in systemic lupus erythematosus patient CD4+ T cells. Our findings reveal a direct link between TRAF5-mediated ubiquitination and RORγt protein regulation, which may aggravate inflammatory progress and provide new therapeutic drug targets for autoimmune diseases.

T helper 17 (Th17) cells not only play critical roles in protecting against bacterial and fungal infections but are also involved in the pathogenesis of autoimmune diseases. The retinoic acid-related orphan receptor (RORγt) is a key transcription factor involved in Th17 cell differentiation through direct transcriptional activation of interleukin 17(A) (IL-17). How RORγt itself is regulated remains unclear. Here, we report that p300, which has histone acetyltransferase (HAT) activity, interacts with and acetylates RORγt at its K81 residue. Knockdown of p300 downregulates RORγt protein and RORγt-mediated gene expression in Th17 cells. In addition, p300 can promote RORγt-mediated transcriptional activation. Interestingly, the histone deacetylase (HDAC) HDAC1 can also interact with RORγt and reduce its acetylation level. In summary, our data reveal previously unappreciated posttranslational regulation of RORγt, uncovering the underlying mechanism by which the histone acetyltransferase p300 and the histone deacetylase HDAC1 reciprocally regulate the RORγt-mediated transcriptional activation of IL-17.

RORγt is a key transcription factor that controls the development and function of inflammatory Th17. The mechanisms that regulate RORγt stability remain unclear. We report that Th17 cells highly express the deubiquitinase ubiquitin-specific protease (USP)4, which is essential for maintaining RORγt and Th17 cell function. Inhibition of the catalytic activity of USP4 with vialinin A, a compound derived from Chinese traditional medicine, dampened Th17 differentiation. USP4 interacted and deubiquitinated K48-linked polyubiquitination of RORγt, thereby promoting RORγt function and IL-17A transcription. Interestingly, TGF-β plus IL-6 enhanced USP4-mediated deubiquitination of RORγt. Moreover, USP4 and IL-17 mRNA, but not RORγt mRNA, were significantly elevated in CD4(+) T cells from patients with rheumatic heart disease. Thus, USP4 could be a novel therapeutic target for the treatment of Th17-modulated autoimmune diseases.

Th17 cells are a new subset of CD4+ T cells involved in the clearance of extracellular pathogens and fungi. Accumulating evidence suggests that Th17 cells and their signature cytokines have a pivotal role in the pathogenesis of multiple autoimmune-mediated inflammatory diseases. Here, we summarize recent research progress on Th17 function in the development and pathogenesis of autoimmune diseases. We also propose to identify new small molecule compounds to manipulate Th17 function for potential therapeutic application to treat human autoimmune diseases, including rheumatoid arthritis, systemic lupus erythematosus, Sjögren’s syndrome, inflammatory bowel disease, and multiple sclerosis.

Stable retinoic acid-related orphan nuclear receptor gamma t (ROR gamma t) expression is pivotal for the development and function of Th17 cells. Here we demonstrate that expression of the transcription factor ROR gamma t can be regulated through deubiquitination, which prevents proteasome-mediated degradation. We establish that USP17 stabilizes ROR gamma t protein expression by reducing ROR gamma t polyubiquitination at its Lys-360 residue. In contrast, knockdown of endogenous USP17 in Th17 cells resulted in decreased ROR gamma t protein levels and down-regulation of Th17-related genes. Furthermore, USP17 expression was up-regulated in CD4(+) T cells from systemic lupus erythematosus patients. Our data reveal a molecular mechanism in which ROR gamma t expression in Th17 cells can be positively regulated by USP17, thereby modulating Th17 cell functions.

胸腺基质淋巴细胞生成素是近期发现的一种细胞因子,其结构和功能类似于IL-7,通过胸腺基质淋巴细胞生成素受体发挥生物学作用。该因子对树突状细胞活化和诱导淋巴细胞及其亚群的分化、成熟有着重要的调控作用,并参与支气管哮喘、过敏性皮炎、过敏性鼻炎等超敏反应性疾病的发生发展。

Risk factors of mydelodysplastic syndromes (MDS) remain largely unknown. We conducted a hospital‐based case–control study consisting of 403 newly diagnosed MDS patients according to World Health Organization classification and 806 individually gender and age‐matched patient controls from 27 major hospitals in Shanghai, China, to examine relation of lifestyle, environmental, and occupational factors to risk of MDS. The study showed that all MDS (all subtypes combined) risk factors included anti tuberculosis drugs [odds ratio (OR) adj = 3.15; 95% confidence interval (CI) = 1.22–8.12] as an independent risk factor, benzene (OR adj = 3.73; 95% CI = 1.32–10.51), hair dye use (OR = 1.46; 95% CI = 1.03–2.07), new building and renovations (OR = 1.69; 95% CI = 1.11–2.00), pesticides (OR = 2.16; 95% CI = 1.22–3.82), and herbicides (OR = 5.33; 95% CI = 1.41–20.10) as relative risk factors. Risk factors of MDS subtype refractory cytopenia with multiple dysplasia (RCMD) were benzene (OR adj = 5.99; 95% CI = 1.19–30.16) and gasoline (OR adj = 11.44; 95% CI = 1.31–100.03) as independent risk factors, and traditional Chinese medicines (OR = 2.17; 95% CI = 1.15–4.07), pesticides (OR = 2.92; 95% CI = 1.37–6.25), and herbicides (OR = 12.00; 95% CI = 1.44–99.67) as relative risk factors. Smoking tobacco was significantly associated with refractory anemia with excess of blasts (RAEB) (OR adj = 2.43; 95% CI = 1.02–5.77). Education is shown as an independent protective factor against all MDS (OR adj = 0.90; 95% CI = 0.83–0.99) and RCMD (OR adj = 0.89; 95% CI = 0.79–0.99). These findings suggest that multiple modifiable behavioral, environmental, and occupational factors play a role in MDS etiology, and various MDS subtypes may have different susceptibility. Am. J. Hematol. 86:163–169, 2011. © 2010 Wiley‐Liss, Inc.

Objective To investigate the effects of dexamethasone（DEX）on the secretion of interleukin （IL）-17 and interferon（IFN）-γ and the proportion of Th17,Tc17,Th1 ,Tc1 cells in peripheral blood mononuclear cells（PBMCs）of patients with systemic lupus erythematosus（SLE）. Methods Thirty hospitalized SLE patients were recruited and twenty-two healthy volunteers were recruited as healthy controls. PBMCs were separated from SLE patients and healthy controls and then was cultured in vitro by medium or PMA/Ionomycin or PMA/Ionomycin ＋dexamethasone for six hours. Four- color immunofluorescent staining and flow cytometric assay were used to analyze the percentage of Th17,Tc17,Th1,Tc1 cells in PBMCs. Concentrations of IL-17 and IFN-γ in plasma and the supernatants of PBMCs which were cultured for 24 hours were measured by enzyme linked immunosorbent assay （ELISA）. Results The plasma concentrations of IL-17 and IFN-γwere elevated in SLE patients as compared to the controls（P 〈 0.05）. No significant differences were observed between patients and controls for the spontaneous production of IL-17 and IFN-γ or percentage of T subsets expressed by PBMCs. After the stimulation of PMA,compared with the controls,the level of IL-17 was significantly elevated in the supematants of PBMCs and the percentages of Th17 and Tc1 in SLE patients increased significantly（P 〈 0. 05）. However,there showed no significant differences between SLE patients and the controls for the percentages of Th1 and Tc17 cells. DEX could significantly decrease the production of IL-17（P 〈 0. 01）and the percentages of Th17,Tc1 cells by the active PBMCs（P 〈 0. 05）. Conclusions There is abnormal expression of T subset cells and their cytokines in vivo of SLE patients. DEX can interfere with immunological pathological process in the cytokine network imbalance of SLE patients and shows powerful inhibition of IL - 17. Our results may provide some laboratory evidence for the clinical application of corticosteroids. Key words: Systemic lupus erythematosus Interleukin-17 Interferon-γ Helper T cell Dexamethasone

The methylenetetrahydrofolate reductase (MTHFR) encodes a major enzyme in folate metabolism. It has been suggested that two MTHFR polymorphisms, 677C > T and 1298A > C, influence risk of acute lymphoblastic leukemia (ALL). Most studies on relation of MTHFR polymorphisms to ALL susceptibility have been in pediatric populations because ALL is relatively rare in adults. Here, we report a case-control study of 127 Chinese patients with adult precursor B lymphoblastic leukemia (B-ALL) to examine correlation between the MTHFR polymorphisms and B-ALL susceptibility in adults. Our data show that although the prevalence of genotype 1298CC was significantly higher in the female patients than in the controls (P = 0.04), the differences in distributions of combined genotypes of 1298CC with either 677CC or 677CT between the cases and the controls were statistically insignificant. Haplotype analysis revealed no significant difference between the cases and the controls. The prevalence for joint MTHFR genotypes 677CC/1298AC was significantly lower in the female B-ALL cases than in the controls [odds ratio (OR) = 0.06, 95% CI = 0.00-0.53, P = 0.0033] and no differences among the men [OR = 0.71, 95% CI = 0.20-2.53, P = 0.55], suggesting that protective effects of combined MTHFR 677CC/1298AC genotypes on susceptibility of adult B-ALL are gender bias toward women with 677CC/1298AC women being at a 17-fold reduced odds to develop B-ALL.

Objective To summarize results of the correlation of tumor necrosis factor-α (TNF-α) promoter-308A/G polymorphism with systemic lupus erythematosus (SLE) susceptibility in Chinese populations.Methods We collected all the publications about the correlation between TNF-α promoter-308A/G polymorphism and SLE in Chinese populations by searching PubMed,EBSCO,CBM,CNKI and Wanfang Data before the date of March 20,2010.Meta-analysis was performed for checking the difference between two groups about genotypes such as AA versus GG,GA versus GG,AA versus GG+GA,GA+AA versus GG,and A allele versus G allele.Results A total of 8 studies involving 731 SLE patients and 901 healthy people were included.The meta-analysis of total populations showed that,there was no significant correlation between A allele and increased SLE risk (OR=1.42,95%CI 0.97 to 2.09,P=0.07);the meta-analyses of populations in different regions showed there was no significant correlation of A allele and increased SLE risk in Chinese Taiwan populations (OR=1.04,95%CI 0.77 to 1.40,P=0.82).Moreover,there was no significant difference between SLE group and control group in the genotypes of AA versus GG,GA versus GG,AA versus GG+GA,and GA+AA versus GG.Conclusion This meta-analysis dosen't demonstrate the correlation between TNF-α promoter-308A/G polymorphism and SLE in Chinese populations.

Objective To determine the protein and mRNA levels of interleukin-17(IL-17) in the peripheral blood of patients with systemic lupus erythematosus(SLE),and to analyze the relationship between IL-17 and disease activity. Methods Twenty-six hospitalized SLE patients and twenty-one normal controls were studied.Plasma protein and mRNA of IL-17 in peripheral blood were measured by ELISA and Real-time RT-PCR respectively. Results IL-17 level and its mRNA level increased in SLE patients compared with that in normal controls.Plasma concentration of IL-17 showed a significant positive correlation with SLEDAI score and anti-dsDNA antibody level,and a significant negative correlation with serum C3 level. Conclusions Plasma IL-17 protein and mRNA expression level in SLE patients increased significantly and had close relationship with disease activity,which might suggest that IL-17 play an important role in the pathogenesis of SLE.

为了研究系统性红斑狼疮(systemic lupus erythematosus,SLE)患者外周血辅助性T(Th)细胞及细胞毒性T(Tc)细胞表达细胞因子的水平,我们采用四色流式细胞术检测SLE患者外周血CD3+CD8-T细胞(Th细胞)和CD3+CD8+T细胞(Tc细胞)中IFN-γ和IL-17的表达水平,探讨这些变化与疾病的关系.

Objective To explore the change pattern of platelet associated antibodies levels in benzene exposed workers.Methods One hundred and twenty-one benzene-exposed workers and 110 workers without benzene exposure were enrolled in this study.The general information of subjects was obtained by questionnaire.Levels of platelet associated antibodies,such as PAIgG,PAIgA,PAIgM were analysed using ELISA.Results The air concentrations of benzene in workplaces varied from 0.25mg/m3 to 15.70mg/m3,the individual cumulative exposure doses of benzene in benzene workers were 1.71mg/(m3 ·a) to 74.20 mg/(m3·a).Levels of PAIgG,PAIgA,PAIgM and the abnormal detection rate of PAIgA were obviously risen in benzene exposed workers(P<0.05) compared to those of the controls,and the rise of PAIgA,PAIgM levels was cumulative exposure dose dependent.Besides,the PAIg level in benzene workers with smoking or drinking habit was obviously higher than that of the controls.Conclusion The results suggested that the levels of platelet associated antibodies may be the early and sensitive biomarker in workers exposed to low concentration of benzene.Smoking and drinking habits may have joint effect with these toxicity of benzene.

Objective To determine the protein and mRNA levels ofinterleukin-17 (IL-17) and the proportion of Th17 cells in the peripheral blood of patients with systemic lupus erythematosus (SLE) and their clinical significance is analyzed. Methods Twenty-five hospitalized SLE patients were recruited and twentytwo healthy volunteers were enrolled as normal controls. Plasma protein and mRNA of IL-17 in the peripheral blood were measured by enzyme-linked immunosorbent assay and real time-PCR respectively. Flow cytometric assay was used to analyze the percentage of Th17 cells in SLE patients. The relationship between IL-17/Th17 cells and clinical or laboratory parameters of SLE patients was explored. Students' t-test and Spearman's correlation was used to evaluate the relationship between mRNA level and inflammatory parameters. Results The plasma concentration and mRNA level of IL-17 was significantly elevated in SLE patients as compared to the normal controls (P＜0.05). The percentage of Th17 cells in patients with SLE was higher than that of normal controls and was significantly increased in more active SLE patients and SLE with nephritis than less active SLE and SLE without nephritis (P＜0.05). Both plasma levels of IL-17 and the proportion of Th17 cells were positively correlated with SLEDAI (r=0.681, P＜0.01; r=0.426, P=0.034). Conclusion Plasma IL-17 protein and mRNA expression level and the percentage of Th17 cells in SLE patients are all significantly elevated and the close relationship between IL-17/Th17 cells and disease activity suggests that IL-17/Th17 may play an important role in the pathogenesis of SLE.

目的 研究系统性红斑狼疮(SLE)患者血浆IL-17、干扰素(IFN)-γ水平及外周血辅助性T细胞(Th)17和Th1细胞表达比例,探讨其临床意义.方法 用酶联免疫吸附法检测SLE患者及对照组血浆中IL-17、IFN-γ浓度;运用流式细胞术检测SLE患者外周血单个核细胞(PBMCs)中Th17、Th1细胞表达比例.进一步分析Th17/Th1细胞及其相关因子与SLE临床实验室指标的相关性.结果 SLE患者PBMCs中Th17细胞比例显著高于对照组,且SLE活动期患者Th17细胞百分比高于非活动期患者(P<0.05),而SLE患者Th1细胞比例与对照组无差异(P>0.05).SLE患者血浆IL-17水平、Th17细胞数与SLE疾病活动性指数呈正相关.结论 SLE患者体内IL-17水平、Th17细胞比例显著升高,且与疾病活动性明显相关,提示IL-17/Th17细胞在SLE发病机制中可能发挥重要作用.