Interleukin-17 in systemic lupus erythematosus: A comprehensive review

Abstract

Systemic lupus erythematosus (SLE) is a complicated autoimmune disease of multifactorial pathoaetiology. One of the most serious manifestations is lupus nephritis. The pathogenesis of SLE has not been well elucidated, but it has been reported that interleukin-17 (IL-17) and Th17 cells play important roles in the pathogenesis of SLE. IL-17A, a member of IL-17 family, amplifies the immune response by inducing the local production of chemokines and cytokines, recruiting neutrophils and monocytes, augmenting the production of autoantibodies, and aggravating the inflammation and damage of target organs such as the kidney in SLE. In recent years, several IL-17A pathway inhibitors have advanced into clinical trials, including the anti-IL-17A monoclonal antibody and the anti-17RA monoclonal antibody. Several agents have shown great success in Phase II trials in multiple autoimmune diseases such as psoriasis, rheumatoid arthritis, ankylosing spondylitis, multiple sclerosis, and non-infectious uveitis, which has sparked the urgent need of anti-IL-17A as innovative therapeutic option in controlling disease activity of moderate-to-severe SLE. Here, we review and summarize current progress in IL-17A and SLE from in vitro studies, human expression studies, and animal models, providing novel insight into its therapeutic potential.     

Decreased Secretion of Th2 Cytokines Precedes Up-regulated and Delayed Secretion of Th1 Cytokines in Activated Peripheral Blood Mononuclear Cells from Patients with Insulin-Dependent Diabetes Mellitus

Recent evidence suggests that autoimmune animal diabetes is associated with an imbalance between the Th1 and Th2 arms of the cellular immune system. However, limited data is available regarding the Th1/Th2 imbalance in human Insulin dependent diabetes mellitus (IDDM) patients. Therefore, we examined the peak levels, secretory pattern and total cytokine production (calculated as the area under the curve, AUC) of the Th1 cytokines, IL-2 and IFN-γ, and Th2 cytokines, IL-4 and IL-10, from stimulated peripheral blood mononuclear cells, from 17 IDDM patients and 24 normal controls. In contrast to controls, diabetic patients were characterized by an early, uniformly low secretion of Th2 cytokines, followed by a late increased secretion of Th1 cytokines. This resulted in significant differences in secretory patterns of IFN-γIL-2, IL-4 and IL-10 between the two groups;P<0.001,P<0.005,P<0.005 andP<0.001, respectively. No correlation was found in the diabetic patients between any profiles of the cytokines and their various clinical parameters, including age, gender, disease duration, insulin requirements or glycated hemoglobin levels. In conclusion, our data provides the first comprehensive evidence for an independent and persistent impairment of both Th1 and Th2 cytokine secretory patterns in IDDM patients.     

Interleukin-17 and systemic lupus erythematosus: current concepts

The emerging role of interleukin (IL)-17 as a hallmark proinflammatory cytokine of the adaptive immune system, produced primarily by a new T helper cell subset termed ‘Th17’, has received considerable attention. Differentiation of Th17 cells is driven by the simultaneous presence of transforming growth factor-β and certain inflammatory cytokines (e.g. IL-6, IL-21), and recent studies have shown that inflammation instigated by IL-17-producing cells is central to the development and pathogenesis of several human autoimmune diseases and animal models of autoimmunity. In this review, we focus on the information regarding IL-17 and systemic lupus erythematosus (SLE), a chronic autoimmune disease. The work that has explored the development and behaviour of IL-17-producing cells in SLE is discussed, and different mechanisms by which IL-17 could potentially augment inflammation and autoantibody production in the context of SLE are proposed.     

Effects of atorvastatin on the Th1/Th2 polarization of ongoing experimental autoimmune myocarditis in Lewis rats

OBJECTIVE: Experimental autoimmune myocarditis (EAM) in rats is a T cell-mediated disorder and the involvement of Th1/Th2 unbalance has been demonstrated. This study was designed to test the hypothesis that 3-hydroxy-3-methyl-glutaryl coenzyme A (HMG-CoA) reductase inhibitor, atorvastatin, affects T cell-mediated autoimmunity through modulating the balance of Th1/Th2 and reduces the severity of EAM. METHODS: Myocarditis was induced in 23 Lewis rats by injection of porcine cardiac myosin. High-dose (10 mg/kg/day) or low-dose (1 mg/kg/day) atorvastatin or vehicle was administered orally for 3 weeks to rats with EAM at the same time of immunization. Seven Lewis rats received neither immunization nor statins therapy were used as normal controls. On day 21 after immunization (the climax of inflammation), echocardiography was examined and the severity of myocarditis was evaluated by histopathological evaluation. The area ratio (affected/entire area percentage) of myocardial lesions was determined in histological sections. Heart weight/body weight ratio was determined and the serum lipid levels were measured. Levels of serum IFN-gamma, IL-2, IL-4 and IL-10 were measured by ELISA. RESULTS: Cardiac function was improved in the two atorvastatin-treated groups compared to the untreated group. Heart weight/body weight ratio and the degree of inflammation were significantly lower in the two dosage statin-treated groups than that in the untreated one. Furthermore, treatment with atorvastatin decreased the expression levels of Th1 cytokine (IFN-gamma and IL-2), and increased the expression levels of Th2 cytokine (IL-4 and IL-10). Atorvastatin attenuated the histopathological severity of myocarditis. Plasma lipid levels did not differ between the groups. CONCLUSIONS: Atorvastatin ameliorates EAM by inhibiting T cell responses and suppressing Th1-type and inflammatory cytokines production and this activity is independent of cholesterol reduction, whereas Th2-type cytokines production was promoted. Atorvastatin may have beneficial effects on myocarditis by modulating the Th1/Th2 balance. These results demonstrate an important role of Th1/Th2 polarization in the pathogenesis of EAM and suggest that HMG-CoA reductase blockade may be a promising new strategy for the treatment of organ specific autoimmune diseases.     

Disturbed Th1, Th2, Th17 and T(reg) balance in patients with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease accompanied by disturbed T-cell homeostasis. Dysbalance of T-helper-cell (Th) subsets (Th1/Th2/Th17) and regulatory T-cells (T(regs)) is suggested to contribute to the pathogenesis of SLE. Recent reports suggest functional deviation of T(regs) in terms of producing IL-17A, a process that may be aberrant in SLE. Therefore, we analyzed these T-cell subsets in SLE to test the hypothesis that aberrant T-cell subset skewing is present in SLE-patients. We investigated simultaneously the intracellular cytokines IFN-γ, IL-4 and IL-17A in CD4(+)T-cells as well as in T(regs). Skewing of T-cell subsets towards Th17 cells was observed in SLE-patients. Although the proportion of T(regs) was similar between SLE-patients and healthy controls, the ability of T(regs) to express IFN-γ and IL17A was impaired in SLE-patients. Even in quiescent SLE-patients T-cell homeostasis is aberrant in terms of skewing towards IL-17 producing T-cells.     

Th17及Th17型细胞因子与炎症性肠病

Th17细胞已被划分为一个不同于Th1、Th2和Treg的新的T细胞亚群,以分泌IL-17为主要特征。Th17在防御胞外细菌感染、介导慢性炎症和自身免疫性疾病的发病机制中发挥重要作用。炎症性肠病属于自身免疫性疾病的一种,免疫调节紊乱是其发病的关键因素。免疫学和基因学的发现表明Th17及Th17效应因子在炎症性肠病发病机理中起重要作用。对Th17的进一步深入研究可以加深我们对相关疾病发病机制的认识并指导临床治疗。     

CD4~+效应T细胞在自身免疫性溶血性贫血患者外周血的变化研究

目的研究自身免疫性溶血性贫血(AIHA)患者外周血中效应T细胞亚群Th1和Th17数量和比例的变化,探讨其在AIHA发病中的作用。方法选择30例AIHA患者,分离外周血单核细胞(PBMC),采用流式细胞术检测Th1和Th17细胞频率,用ELISA测定培养上清中IFN-γ和IL-17水平,并与健康对照组比较。结果 AIHA患者PBMC中IFN-γ+Th1和IL-17+Th17细胞频率均显著高于健康对照组(P<0.01);而且,AIHA患者外周血IL-17水平明显高于健康对照组(P<0.05),但IFN-γ水平在患者和正常人之间差异不显著。结论Th17与Th1细胞亚群可能参与AIHA患者的免疫学发病机制。     

Th1 and Th2 Cytokine Modulation by IL-10/IL-12 Imbalance in Autoimmune Haemolytic Anaemia (AIHA)

Recent studies about autoimmune diseases in animal models and in humans focused their attention on lymphocyte activation and in vitro cytokine production. The respective contribution of the Th1 and Th2 cytokines to the pathogenesis of autoimmune diseases is still a matter of debate. In this study the role of IL-2, IL-4, IFN- &#110, IL-10 and IL-12 cytokines were investigated by examining their spontaneous and mitogen-induced (OKT3 and PHA or LPS) synthesis and T-cells proliferative response by peripheral blood mononuclear cells to determine their role in the pathogenesis of AIHA. Thirteen patients affected by AIHA, idiopathic or associated with other diseases, and 13 healthy subjects, randomly selected from a group of blood donors, were investigated. This study indicated that AIHA is characterised by increased basal synthesis of IL-4 and decreased levels of IFN- &#110 compared with healthy controls ( p <0,01). These results suggest that there is a basal decrease of Th1 cytokine and an increase of the Th2 ones. Enhanced IL-2 levels in AIHA patients are likely due to the necessity of a T-cell proliferation stimulus rather than produced as Th1 prevalent stimulation. Furthermore, it has been observed a significant increase in IL-12 production in LPS stimulated cultures from healthy controls, but not in AIHA patients, that shows IL-10 increased levels, which could cause a secondary decrease in IFN- &#110 production and a stimulation of Th2 differentiation. These observations indicate that decreased production of Th1-type cytokines and prevalent Th2 ones leading to autoantibodies production in AIHA may be secondary to the imbalance between IL-10 and IL-12. These results strongly suggest that manipulation of the cytokine network, i.e. IL-10/IL-12 balance, maintained by cells of the innate immune system, can have a strong effect on the incidence of AIHA and their modulation might be useful for a therapeutic control of the disorder.     

The elevated expression of Th17-related cytokines and receptors is associated with skin lesion severity in early systemic sclerosis

ObjectiveThe objective was to survey the expression and localization of Th17-related cytokines and their correlation with skin lesion severity in early systemic sclerosis (SSc).MethodsThe mRNA expression was detected by real-time quantitative polymerase chain reaction (RT-qPCR) from 21 SSc patients and 12 healthy controls (HC). The protein expression was examined by immunohistochemistry (IHC) and Western blotting.ResultsThe RT-qPCR analysis showed a significantly higher expression of IL-17A, IL-21, IL-22, IL-26, IL-17RA, IL-21R, and IL-22R1 mRNA; consistently, the IHC analysis showed an over-expression of IL-17RA, IL-21R and IL-22R1 and the Western blotting analysis showed an over-expression of IL-17A, IL-21, IL-21R and IL-22R1 in early SSc skin lesions. The mRNA levels of IL-21 were higher in diffuse cutaneous than limited cutaneous SSc lesions. The mRNA expression of IL-26, IL-22, IL-22R1, mRNA and protein expression of IL-17A, IL-21, IL-21R were positively correlated with the modified Rodnan skin score of SSc. In addition, the mRNA levels of ICAM-1 were positively correlated with IL-17A/IL-17RA, and VEGFA and IL-4 were both positively correlated with IL-21/IL-21R, while TGF-β were moderately negatively correlated with IL-22/IL-22R1.ConclusionsTh17 cytokines contribute to progression in early SSc skin lesions. IL-21/IL-21R could act as potential biomarkers presenting early SSc skin lesions severity.     

Both Th1- and Th2-derived cytokines in serum are elevated in Graves' ophthalmopathy

Increased serum cytokine levels have been reported in patients with autoimmune thyroid disease, but less is known about their levels in patients with Graves' ophthalmopathy (GO). It is not known whether GO is a cell-mediated or humoral autoimmune disease. We investigated whether serum cytokines are elevated in GO patients and whether the cytokines were Th1- or Th2-derived. In addition, elevated cytokines might reflect the activity of GO, and thus we investigated whether cytokine levels could predict the clinical response to orbital radiotherapy. We studied 62 consecutive patients with moderately severe untreated GO and 62 healthy controls, matched for sex, age and smoking habits. Serum concentrations of IL-1RA, sIL-2R, IL-6, sIL-6R, tumour necrosis factor-alpha (TNF-alpha) RI and II and sCD30 were measured using highly sensitive ELISAs, in the patients before and 3 and 6 months after radiotherapy. All patients were euthyroid, with anti-thyroid drugs, before and during the entire study period. All baseline cytokine and cytokine receptor levels were significantly elevated in GO patients compared with healthy controls, except for IL-1RA. The levels did not correlate with parameters of the thyroid disease, nor with the duration, activity or severity of GO. However, backward logistic regression analysis showed that IL-6, sCD30 and TNFalphaRI were able to predict a beneficial response to orbital radiotherapy. We therefore conclude that both Th1- and Th2-derived cytokines are elevated in GO patients compared with its controls. IL-6, sCD30 and TNFalphaRI had some value for predicting therapeutic outcome to orbital irradiation, and may thus reflect active eye disease.     

初发SLE病人Th1/Th2及调控因子IL-18基因研究

目的：探讨未经药物治疗初发狼疮病人Th1/Th2细胞亚群分布及其调控细胞因子、细胞因子受体基因表达的差异，试图揭示系统性红斑狼疮发病的免疫紊乱机理。方法：运用三色荧光标记法流式细胞术检测42例未经药物治疗初发狼疮病人细胞亚群分布，并以10例正常人作对照；ABI7700 real-time PCR法同时检测 38例未经药物治疗初发狼疮病人和 28例正常人IL-18及其受体mRNA表达水平的差异。结果：①初发狼疮病人Th1较正常人明显减低（P<0．05），但Th1/Th2无显著性改变。②与正常组相比，SLE组病人IL-18 mRNA及其受体表达较正常人明显降低（P<0．05）；③面部红斑组病人Th1/Th2较正常人明显降低（P<0．05）；④关节炎组SLE病人较无关节炎病人IL-18表达降低。结论SLE是一种以Th1细胞下降，Th2细胞相对占优势的免疫介导的自身免疫性疾病，源于诱导向Th1细胞分化的IL-18及其受体减少和细胞因子间失衡所致。     

Th17细胞与Graves’病

Th17细胞是近几年研究发现的一类不同于Th1和Th2细胞亚群的新型CD4^＋效应T细胞。该类细胞是由天然T细胞前体分化而来,具有独立分化和发育调节机制,在其分化过程中需要IL-6和转化生长因子。B、转录因子RORα及STAT3等的参与,主要分泌IL-17A、IL-17F、IL-22等多种细胞因子,并参与多种炎症、自身免疫性疾病的发生和发展。Graves’病（GD）是一种器官特异性自身免疫病,Th2细胞介导的体液免疫在其发病中起着重要作用。近来有研究提示IL-23／Th17轴亦参与GD的发展。因此了解Th17细胞分化的影响因素、产生的细胞因子以及在免疫性疾病GD中的作用具有重要的临床意义。     

Effects of atorvastatin on the Th1/Th2 polarization of ongoing experimental autoimmune myocarditis in Lewis rats

ObjectiveExperimental autoimmune myocarditis (EAM) in rats is a T cell-mediated disorder and the involvement of Th1/Th2 unbalance has been demonstrated. This study was designed to test the hypothesis that 3-hydroxy-3-methyl-glutaryl coenzyme A (HMG-CoA) reductase inhibitor, atorvastatin, affects T cell-mediated autoimmunity through modulating the balance of Th1/Th2 and reduces the severity of EAM.MethodsMyocarditis was induced in 23 Lewis rats by injection of porcine cardiac myosin. High-dose (10 mg/kg/day) or low-dose (1 mg/kg/day) atorvastatin or vehicle was administered orally for 3 weeks to rats with EAM at the same time of immunization. Seven Lewis rats received neither immunization nor statins therapy were used as normal controls. On day 21 after immunization (the climax of inflammation), echocardiography was examined and the severity of myocarditis was evaluated by histopathological evaluation. The area ratio (affected/entire area percentage) of myocardial lesions was determined in histological sections. Heart weight/body weight ratio was determined and the serum lipid levels were measured. Levels of serum IFN-γ, IL-2, IL-4 and IL-10 were measured by ELISA.ResultsCardiac function was improved in the two atorvastatin-treated groups compared to the untreated group. Heart weight/body weight ratio and the degree of inflammation were significantly lower in the two dosage statin-treated groups than that in the untreated one. Furthermore, treatment with atorvastatin decreased the expression levels of Th1 cytokine (IFN-γ and IL-2), and increased the expression levels of Th2 cytokine (IL-4 and IL-10). Atorvastatin attenuated the histopathological severity of myocarditis. Plasma lipid levels did not differ between the groups.ConclusionsAtorvastatin ameliorates EAM by inhibiting T cell responses and suppressing Th1-type and inflammatory cytokines production and this activity is independent of cholesterol reduction, whereas Th2-type cytokines production was promoted. Atorvastatin may have beneficial effects on myocarditis by modulating the Th1/Th2 balance. These results demonstrate an important role of Th1/Th2 polarization in the pathogenesis of EAM and suggest that HMG-CoA reductase blockade may be a promising new strategy for the treatment of organ specific autoimmune diseases.     

Annexin-A1 restricts Th17 cells and attenuates the severity of autoimmune disease

Annexin-A1 (Anx-A1) is an endogenous anti-inflammatory molecule and while described as a repressor of innate immune responses, the role of Anx-A1 in adaptive immunity, and in particular in T helper (Th) cell responses, remains controversial. We have used a T-cell mediated mouse model of retinal autoimmune disease to unravel the role of Anx-A1 in the development of autoreactive Th cell responses and pathology. RBP_1–20-immunized C57BL/6 Anx-A1^−/− mice exhibit significantly enhanced retinal inflammation and pathology as a result of an uncontrolled proliferation and activation of Th17 cells. This is associated with a limited capacity to induce SOCS3, resulting in un-restricted phosphorylation of STAT3. RBP_1–20-specific CD4⁺ cells from immunized Anx-A1^−/− animals generated high levels of Th17 cells-associated cytokines. Following disease induction, daily systemic administration of human recombinant Anx-A1 (hrAnx-A1), during the afferent phase of disease, restrained autoreactive CD4⁺ cell proliferation, reduced expression of pro-inflammatory cytokines IL-17, IFN-γ and IL-6 and attenuated autoimmune retinal inflammatory disease. Furthermore, in man, Anx-A1 serum levels when measured in active uveitis patient sera were low and associated with the detection of IgM and IgG anti-Anx-A1 antibodies when compared to healthy individuals. This data supports Anx-A1 as an early and critical regulator of Th17 cell driven autoimmune diseases such as uveitis.     

T‐bet is essential for Th1‐mediated,but not Th17‐mediated,CNS autoimmune disease

T cells that produce both IL‐17 and IFN‐γ, and co‐express ROR‐γt and T‐bet, are often found at sites of autoimmune inflammation. However, it is unknown whether this co‐expression of T‐bet with ROR‐γt is a prerequisite for immunopathology. We show here that T‐bet is not required for the development of Th17‐driven experimental autoimmune encephalomyelitis (EAE). The disease was not impaired in T‐bet^?/? mice and was associated with low IFN‐γ production and elevated IL‐17 production among central nervous system (CNS) infiltrating CD4⁺ T cells. T‐bet^?/? Th17 cells generated in the presence of IL‐6/TGF‐β/IL‐1 and IL‐23 produced GM‐CSF and high levels of IL‐17 and induced disease upon transfer to naïve mice. Unlike their WT counterparts, these T‐bet^?/– Th17 cells did not exhibit an IL‐17→IFN‐γ switch upon reencounter with antigen in the CNS, indicating that this functional change is not critical to disease development. In contrast, T‐bet was absolutely required for the pathogenicity of myelin‐responsive Th1 cells. T‐bet‐deficient Th1 cells failed to accumulate in the CNS upon transfer, despite being able to produce GM‐CSF. Therefore, T‐bet is essential for establishing Th1‐mediated inflammation but is not required to drive IL‐23‐induced GM‐CSF production, or Th17‐mediated autoimmune inflammation.     

Th22, but not Th17 Might be a Good Index to Predict the Tissue Involvement of Systemic Lupus Erythematosus

Purpose

T-helper (Th) cells abnormalities are considered to be associated with the pathogenesis of Systemic lupus erythematosus (SLE). Recently, The Th22 cells have been identified and implicated in the pathogenesis of autoimmune diseases such as Rheumatoid arthritis (RA), although therir role in Systemic lupus erythematosus (SLE) remains unclear. The present study intends to investigate their roles in SLE.

Methods

Clinical data were collected in 65 SLE patients and 30 healthy controls. The patients were divided into active and inactive groups. CD4⁺IFN-γ^?IL-17^?IL-22⁺Tcells (Th22 cells),CD4⁺ IFN-γ^?IL-22^?IL-17⁺T cells (Th17 cells),and CD4⁺ IFN-γ⁺ (Th1 cells) were assayed by flow cytometry. Serum interleukin-22 (IL-22) and IL-17 levels were measured by enzyme-linked immunosorbent assay.

Results

The main observation focused on increased Th22 cells in patients with sole lupus skin disease and decreased Th22 cells in patients with sole lupus nephritis. Likewise, concentrations of serum IL-22 were increased in patients with sole lupus skin disease, and decreased in patients with sole lupus nephritis. Additionally, there was a positive correlation between the percentage of Th22 cells and IL-22 production. The percentage of Th17 cells or concentration of serum IL-17 correlated positively with Systemic Lupus Erythematosus Disease Activity Index (SLEDAI).

Conclusion

Th22 seems to be a more significant index to predict the tissue involvement of SLE than Th17, although Th17 may play a role in the activity of SLE.     

Th1、Th2、Th17型细胞因子与糖尿病肾病相关性的研究

糖尿病肾病(diabetic Nephropathy,DN)是导致终末期肾脏病(end-stage renal disease,ESRD)的最主要病因,因此,早期诊断和治疗是糖尿病肾病的诊治要点。但目前糖尿病肾病的确切发病机制尚未完全明确,糖尿病肾病的发生发展与血流动力学改变和代谢的紊乱、氧化应激和炎症等多种因素有关,而细胞因子在2型糖尿病及其相关肾脏并发症的病因、发病机制中也起着重要的作用,各种细胞因子的识别将为糖尿病肾病的诊治提供新的潜在治疗靶点。文章就Th1、Th2、Th17型细胞因子与DN相关性的研究作了综述。     

Th17细胞及IL-17与系统性红斑狼疮

系统性红斑狼疮（SLE）是多种因素相互作用引起的自身免疫性疾病,其发病机制复杂。Th17细胞是最近发现的CD4^＋效应T细胞的新亚群。初始T细胞在TGF—B和IL-6的共同作用下分化发育成为Th17细胞,后者可以分泌IL-17、IL-21、IL-22等多种细胞因子。其中IL-17在多种自身免疫疾病（比如类风湿关节炎和Crohn’s病）中起关键作用,但在SLE中的作用尚不清晰。