Levels of IL-12 in the sera of patients with systemic lupus erythematosus (SLE)--relation to Th1- and Th2-derived cytokines

Potential biomarkers for diagnosis and assessment of disease activity in systemic lupus erythematosus

BACKGROUND

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease involving multiple system functions. Our study aimed to screen out more effective new indicators that can assist clinical diagnosis and judge disease activity.

METHODS

We first screened serum levels of 45 cytokines of SLE patients (n = 3) and healthy controls (n = 3). Subsequently, we selected five elevated cytokines for verification with an expanded sample size. Then, the relationship between cytokines and laboratory parameters was also investigated. Finally, we used receiver operating characteristic (ROC) curves to assess the clinical value of these cytokines.

RESULTS

Through screening of 45 cytokines, 15 were found to be elevated in SLE patients. We chose five cytokines (IL-6, IL-10, IL-1RA, IP-10 and LIF) for further research and found elevated expression of all five cytokines in SLE patients. Serum levels of IL-10, IL-1RA and LIF were positively correlated with SLEDAI-2K score. Besides, the level of IL-10 was significantly positively correlated with serum IgG and erythrocyte sedimentation rate (ESR); IL-1RA was significantly negatively correlated with C3 and C4; and LIF was significantly positively correlated with serum IgG, C-reactive protein (CRP), and ESR. Furthermore, IL-1RA and LIF were strongly positively correlated with 24-hour urine protein levels. The ROC analysis showed that IL-1RA has good diagnostic value, and IL-10 and LIF levels can be utilized to discriminate between active and inactive SLE.

CONCLUSION

IL-1RA can be used as a biomarker for diagnosing SLE, while IL-10 and LIF can be indicators to discriminate between active and inactive SLE.

Longitudinal comparison of IL-6, IL-10, and IL-12 cytokine profiles in adult and childhood-onset systemic lupus erythematosus

Objective

To compare the levels of Th1 (IL-12) and Th2 (IL-6 and IL10) cytokines over a two-year period among systemic lupus erythematosus patients with childhood-onset (cSLE), adult-onset (sSLE), and healthy controls, and correlate with their clinical, laboratory, and treatment manifestations.

Methods

The study included 63 patients with cSLE [57 (90%) women; mean age 19.7 ± 4.3 years (range = 10-29); mean disease duration 7.3 ± 4.2 years (range 2-15)], 67 patients with aSLE [65 (97%) women; mean age of 39.9 ± 11.8 years (range 21-68); disease duration 7.7 ± 3.1 years (range 4-16)], and 40 healthy controls [36 (90%) women; mean age of 29.6 ± 10 years (range 12-49)]. cSLE and aSLE patients were paired by disease duration. Clinical and laboratory manifestations, disease activity (SLEDAI), cumulative damage (SDI), and current drug exposures were evaluated. Symptoms of anxiety and depression were evaluated by the Beck inventory (BAI and BDI, respectively). Th1 (IL-12) and Th2 (IL-6 and IL-10) cytokines were measured by the ELISA test. Data were collected at four different time points (TI, TII, TIII, and TIV) and compared by non-parametric tests.

Results

IL-6 levels were significantly higher in aSLE patients compared to healthy controls at times I, II, and III (TI p = 0.013, TII p = 0.015, TIII p = 0.004, and TIV p = 0.634). However, no difference was observed between cSLE patients and healthy controls (TI p = 0.223, TII p = 0.613, TIII p = 0.341, and TIV p = 0.977). In addition, no difference was observed between aSLE and cSLE patients (TI p = 0.377, TII p = 0.123, TIII p = 0.105, and TIV p = 0.591). The levels of IL-12 were significantly higher in cSLE patients compared to healthy controls at all time points (TI p = 0.04, TII p < 0.001, TIII p = 0.015, and TIV p = 0.021). aSLE patients showed significantly elevated levels when compared to healthy controls at time III and IV (TI p = 0.752, TII p = 0.827, TIII p = 0.011*, and TIV p < 0.001*). cSLE patients showed significantly higher levels than aSLE patients at times I and II (TI p = 0.07*, TII p < 0.001*, TIII p = 0.998, and TIV p = 0.140). In aSLE patients, IL-6 was associated with headache (p = 0.006), arthritis (p = 0.044), and nephritis (p = 0.012); IL-10 was associated with nephritis (p = 0.043), hypocomplementemia (p = 0.001), and disease activity (p = 0.001); in these patients, IL-12 was associated with alopecia (p = 0.025) and leukopenia (p = 0.044). In cSLE patients, IL-6 was associated with arthritis (p = 0.022) and malar rash (p = 0.012).

Conclusion

aSLE and cSLE patients with long disease duration present similar levels of cytokines, despite differences in clinical activity patterns over time.

Association Between the Interferon-γ +874 T/A Polymorphism and the Risk and Clinical Manifestations of Systemic Lupus Erythematosus: A Preliminary Study

Background

Interferon-gamma (IFN-γ) is a pivotal cytokine involved in the development of systemic lupus erythematosus (SLE). The IFN-γ +874 T/A polymorphism has been shown to be related to the susceptibility to SLE in other races, but this has not been investigated in the Chinese Han population.

Methods

We designed this study to interpret the potential correlation between this polymorphism and SLE risk in a Chinese Han population. We included 374 SLE patients and 405 controls in this study. Odds ratios and relevant 95% confidence intervals were figured out to evaluate the potential strength of the association.

Results

Data revealed that the IFN-γ +874 T/A polymorphism showed an association with an enhanced risk of SLE in this Chinese Han population. TA or TA +AA genotype carriers showed an increased risk of developing SLE. Subgroup analyses found that this polymorphism elevated the risk of SLE among females. Additionally, this polymorphism was associated with clinical manifestations of SLE including lupus nephritis, proteinuria, anti-dsDNA antibodies, anti-Sm antibodies, and SLICC/ACR damage index. Furthermore, we conducted a meta-analysis and found that this polymorphism was associated with the risk of SLE, especially among Asians.

Conclusion

Totally, this study detects that the IFN-γ +874 T/A polymorphism is related to the risk and clinical manifestations of SLE in a Chinese Han population.

Simultaneous Presentation of Parvovirus B19 Infection and Systemic Lupus Erythematosus in a Patient: Description and Review of the Literature

We present the case of a 25-year-old woman without medical history, presenting with acute respiratory failure needing mechanical ventilation. Aetiologic screening showed PVB19 primary infection and concomitant SLE flare-up. We discuss the causative interactions between PVB19 and SLE in the pathogenesis of the disease. Difficulty diagnosing inaugural SLE flare-up concomitant with PVB19 infection can lead to delayed diagnosis and treatment. Inversely, overtreating a SLE-mimicking PVB19 infection with immunosuppressive agents can be highly detrimental.

Leveraging Heterogeneity in Systemic Lupus Erythematosus for New Therapies

Systemic lupus erythematosus (SLE) is a multisystem, chronic autoimmune disease where treatment varies by patient and disease activity. Strong preclinical results and clinical correlates have motivated development of many drugs, but many of these have failed to achieve efficacy in clinical trials. FDA approval of belimumab in 2011 was the first successful SLE drug in nearly six decades. In this article, we review insights into the molecular and clinical heterogeneity of SLE from transcriptomics studies and detail their potential impact on drug development and clinical practices. We critically examine the pipeline of SLE drugs, including past failures and their associated lessons and current promising approaches. Finally, we identify opportunities for integrating these findings and drug development with new multidisciplinary advances to enhance future SLE treatment.

The Impact of Cytokines on the Health-Related Quality of Life in Patients with Systemic Lupus Erythematosus

Introduction: Systemic lupus erythematosus (SLE) reduces the health-related quality of life (HRQoL), even during periods of disease quiescence. We investigated whether subclinical inflammation as reflected by cytokine levels is linked with reduced HRQoL. Methods: A cross-sectional study of SLE patients (n = 52, mean age 47.3, 86.5% female) who completed a Short Form Health Survey-36 (SF-36) questionnaire. The clinical and demographic data, scores for the disease activity (SLEDAI-2K), organ damage (SDI), and laboratory data were collected simultaneously. The autoantibody and cytokine levels (IFN-γ, IL-1β, IL-4, IL-6, IL-10, IL-12, IL-17, BAFF, TNF-α, TGF-β1, MIP-1α, MIP-1β and MCP-1 (levels in pg/mL) were quantified by sandwich ELISA. The comparisons and associations were assessed non-parametrically, and a multiple regression determined the effect sizes (ES) of the variables on the SF-36 domain and summary scores. Results: The SF-36 summary and domain scores for SLE patients were significantly (20–40%) lower than in a comparable control group, with the exception of the Mental Health scores (p = 0.06). SLE patients had a normal body mass index (BMI) (median, 24.2 kg/m²), a high rate of smoking (69.2%), and usage of social security benefits (90.4%). TGF-β1 (ES 0.06), IL-12 (ES −0.11), IFN-γ (ES 0.07) and MCP-1 (ES 0.06) influenced the SF-36 domain scores; and MCP-1 (ES 0.04) influenced the Mental Health Summary Score (MCS). Obvious manifestations, including patient visual analogue scale (VAS) (ES −2.84 to −6.29), alopecia (ES −14.89), malar rash (ES −14.26), and analgesic requirement (ES −19.38), independently influenced the SF-36 items; however, the SF-36 scores were not reflected by the physician VAS or disease activity (SLEDAI-2K). Conclusions: Cytokines had a minimal impact on HRQoL in SLE patients, especially compared to visible skin manifestations, central nervous system (CNS) damage, and pain. Better tools are needed to capture HRQoL in measures of disease activity.

Innate lymphoid cell disturbance with increase in ILC1 in systemic lupus erythematosus

The innate lymphoid cell (ILC) is a group of effector cells with diverse important cellular functions in both health and disease states. In comparison with healthy controls, there were increases in circulating ILC in SLE patients. The proportion of ILC1 significantly increased with significant decreases of ILC2 in SLE patients and ILC3 in SLE patients with moderate to severe activity. IL-12, IL-18, IL-25, IL-33, IL-23, IL-1β and IFN-γ were significantly increased in SLE patients. Moreover, IL-12, IL-18 and IL-1β but not IFN-γ correlated significantly with SLEDAI. Successful treatments rapidly reduced them and with certain normalization of the ILC subsets. In addition to increases in ILC1 numbers, ~ 80% of the ILC1 in SLE patients were positive for synthesis of IFN-γ. Plasma from SLE patients were shown to be potent in inducing ILC1. Thus, increased circulating ILC1 might contribute to the pathogenesis of SLE through mounting type 1 immune response.

EDTA/gelatin zymography method to identify C1s versus activated MMP-9 in plasma and immune complexes of patients with systemic lupus erythematosus

Gelatin zymography analysis is a sensitive method and commonly used to characterize and quantify the presence of the gelatinases (MMP‐2 and MMP‐9) in biological samples. In human plasma samples from healthy controls and systemic lupus erythematosus (SLE) patients, we observed a gelatinolytic molecule at 80 kDa, suggestive for activated human MMP‐9. However, by developing and using the EDTA/gelatin zymography method and after purification of the 80 kDa entity, we proved that this molecule was the C1s subunit of the complement system. The zymolytic capacity of C1s was validated and found to be enhanced, in the absence of calcium and in the presence of EDTA. Our findings indicate that for correct identification of gelatinolytic proteins in complex biological samples the use of EDTA/gelatin zymography for enzyme development is advised. In addition, by quantification of EDTA/gelatin zymography analysis and ELISA, we observed that the levels of C1s were higher in plasma and immune complexes of SLE patients than of healthy individuals. Therefore, our data imply that C1s may become a marker for the diagnosis of SLE.

Association of interleukin 22 gene polymorphisms and serum IL-22 level with risk of systemic lupus erythematosus in a Chinese population

The aim of this study was to investigate the association between the single-nucleotide polymorphisms (SNPs) of the interleukin 22 (IL-22) gene and systemic lupus erythematosus (SLE) in a Chinese population. Three IL-22 SNPs (rs2227485, rs2227513 and rs2227491) were genotyped using SNaPshot SNP genotyping assays and identified by sequencing in 314 SLE patients and 411 healthy controls. The IL-22 level of serum was assessed by enzyme-linked immunosorbent assay (ELISA) kits. Data were analysed by spss version 17.0 software. We found that rs2227513 was associated with an increased risk of SLE [AG versus AA: adjusted odds ratio (aOR) = 2·24, 95% confidence interval (CI) = 1·22-4·12, P = 0·010; G versus· A: adjusted OR = 2·18, 95% CI = 1·20-3·97, P = 0·011]. Further analysis in patients with SLE showed that the AG genotype and G allele were associated with an increased risk of renal disorder in SLE (G versus A: aOR = 3·09, 95% CI = 1·30-7·33, P = 0·011; AG versus· AA: aOR = 3·25, 95% CI = 1·35-7·85, P = 0·009). In addition, the concentration of IL-22 was significantly lower in the rs2227513 AG genotype compared with AA genotype (P = 0·028). These results suggest that rs2227513 polymorphism might contribute to SLE susceptibility, probably by decreasing the expression of IL-22.

Expansion of T follicular helper-T helper 1 like cells through epigenetic regulation by signal transducer and activator of transcription factors

OBJECTIVES

T follicular helper (Tfh) cells are critical in the development and progression of systemic lupus erythematosus (SLE). To assess the characteristics and mechanisms of differentiation of Tfh cells, we investigated the phenotype of T helper cells in patients with SLE and underlying epigenetic modifications by cytokine-induced signal transducer and activators of transcription (STAT) family factors.

METHODS

Peripheral blood mononuclear cells from patients and healthy donors were analysed by flow cytometry. CD4⁺ T cells were isolated and cultured under various stimulations. Expression of characteristic markers and phosphorylation of STATs were analysed by flow cytometry and quantitative PCR. Histone modifications were analysed by chromatin immunoprecipitation (ChIP)-PCR.

RESULTS

Differentiation of CD4⁺CXCR5⁺CXCR3⁺Bcl-6⁺T-bet⁺IL-21⁺IFN-γ⁺Tfh-Th1-like cells was induced by interleukin (IL)-12-induced activation of STAT1 and STAT4 simultaneously. The loci of Bcl-6 and T-bet at STAT binding sites were marked by bivalent histone modifications. After IL-12 stimulation, both STAT1 and STAT4 directly bound on BCL6 and TBX21 gene loci accompanied by suppression of repressive histone mark trimethylated histone 3 lysine 27. Levels of serum IL-12 and interferon (IFN)-γ, expression of IL-12 receptors and proportion of CXCR5⁺CXCR3⁺ activated Tfh-Th1-like cells were increased in patients with SLE. Furthermore, the level of pSTAT1, pSTAT4 and T-bet were higher in activated Tfh-Th1-like cells than non-Tfh-Th1 cells.

CONCLUSION

Our findings suggest that IL-12-mediated co-activation of STAT1 and STAT4 alters histone modification, resulting in differentiation of Tfh-Th1-like cells that are characteristically expanded in patients with SLE. This could be one of the underlying mechanisms responsible for expansion of Tfh-Th1-like cells and potentially helpful towards development of cell-specific treatment for SLE.

Conventional DCs from Male and Female Lupus-Prone B6.NZM Sle1/Sle2/Sle3 Mice Express an IFN Signature and Have a Higher Immunometabolism That Are Enhanced by Estrogen

Type I interferons (IFN) are pathogenic in systemic lupus erythematosus (SLE) and were proposed to control the immunometabolism of dendritic cells (DCs). We previously reported that DCs from female lupus-prone mice constitutively overexpress IFN-responsive genes resembling the IFN signature found in SLE patients. As SLE has higher incidence in women than men, more so in women of reproductive age, estrogens are suggested to affect lupus pathogenesis. We investigated the effects of sex and estrogens on the IFN signature in conventional GM-CSF-bone marrow-derived DCs (cDCs), from male and female Triple Congenic B6.NZM.Sle1/Sle2/Sle3 (TCSle) lupus-prone mice or from wild-type C57BL/6 mice, generated with titrations of 17-beta-estradiol (E2). We found that cDCs from prediseased TCSle male mice express the IFN signature as female TCSle cDCs do. Estrogens are necessary but not sufficient to express this IFN signature, but high doses of E2 can compensate for other steroidal components. E2 stimulation, regardless of sex, modulates type I IFN-dependent and type I IFN-independent activation of cDCs in response to TLR stimulation. Finally, we found that TCSle cDCs from both sexes have elevated markers of immunometabolism and estrogens enhance the metabolic pathways in cDCs, suggesting a mechanistic link between estrogens, immunometabolism, and the IFN signature in lupus.

The STAT4 SLE risk allele rs7574865[T] is associated with increased IL-12-induced IFN-γ production in T cells from patients with SLE

Objectives

Genetic variants in the transcription factor STAT4 are associated with increased susceptibility to systemic lupus erythematosus (SLE) and a more severe disease phenotype. This study aimed to clarify how the SLE-associated intronic STAT4 risk allele rs7574865[T] affects the function of immune cells in SLE.

Methods

Peripheral blood mononuclear cells (PBMCs) were isolated from 52 genotyped patients with SLE. Phosphorylation of STAT4 (pSTAT4) and STAT1 (pSTAT1) in response to interferon (IFN)-α, IFN-γ or interleukin (IL)-12, total levels of STAT4, STAT1 and T-bet, and frequency of IFN-γ⁺ cells on IL-12 stimulation were determined by flow cytometry in subsets of immune cells before and after preactivation of cells with phytohaemagglutinin (PHA) and IL-2. Cellular responses and phenotypes were correlated to STAT4 risk allele carriership. Janus kinase inhibitors (JAKi) selective for TYK2 (TYK2i) or JAK2 (JAK2i) were evaluated for inhibition of IL-12 or IFN-γ-induced activation of SLE PBMCs.

Results

In resting PBMCs, the STAT4 risk allele was neither associated with total levels of STAT4 or STAT1, nor cytokine-induced pSTAT4 or pSTAT1. Following PHA/IL-2 activation, CD8⁺ T cells from STAT4 risk allele carriers displayed increased levels of STAT4 resulting in increased pSTAT4 in response to IL-12 and IFN-α, and an augmented IL-12-induced IFN-γ production in CD8⁺ and CD4⁺ T cells. The TYK2i and the JAK2i efficiently blocked IL-12 and IFN-γ-induced activation of PBMCs from STAT4 risk patients, respectively.

Conclusions

T cells from patients with SLE carrying the STAT4 risk allele rs7574865[T] display an augmented response to IL-12 and IFN-α. This subset of patients may benefit from JAKi treatment.

Curcumin: A natural modulator of immune cells in systemic lupus erythematosus

Curcumin is a polyphenol natural product isolated from turmeric, interacting with different cellular and molecular targets and, consequently, showing a wide range of pharmacological effects. Recent preclinical and clinical trials have revealed immunomodulatory properties of curcumin that arise from its effects on immune cells and mediators involved in the immune response, such as various T-lymphocyte subsets and dendritic cells, as well as different inflammatory cytokines. Systemic lupus erythematosus (SLE) is an inflammatory, chronic autoimmune-mediated disease characterized by the presence of autoantibodies, deposition of immune complexes in various organs, recruitment of autoreactive and inflammatory T cells, and excessive levels of plasma proinflammatory cytokines. The function and numbers of dendritic cells and T cell subsets, such as T helper 1 (Th1), Th17, and regulatory T cells have been found to be significantly altered in SLE. In the present report, we reviewed the results of in vitro, experimental (pre-clinical), and clinical studies pertaining to the modulatory effects that curcumin produces on the function and numbers of dendritic cells and T cell subsets, as well as relevant cytokines that participate in SLE.

Predictive biological markers of systemic lupus erythematosus flares: a systematic literature review

BACKGROUND

The aim of this study was to identify the most reliable biomarkers in the literature that could be used as flare predictors in systemic lupus erythematosus (SLE).

METHODS

A systematic review of the literature was performed using two databases (MEDLINE and EMBASE) through April 2015 and congress abstracts from the American College of Rheumatology and the European League Against Rheumatism were reviewed from 2010 to 2014. Two independent reviewers screened titles and abstracts and analysed selected papers in detail, using a specific questionnaire. Reports addressing the relationships between one or more defined biological test(s) and the occurrence of disease exacerbation were included in the systematic review.

RESULTS

From all of the databases, 4668 records were retrieved, of which 69 studies or congress abstracts were selected for the systematic review. The performance of seven types of biomarkers performed routinely in clinical practice and nine types of novel biological markers was evaluated. Despite some encouraging results for anti-double-stranded DNA antibodies, anti-C1q antibodies, B-lymphocyte stimulator and tumour necrosis factor-like weak inducer of apoptosis, none of the biomarkers stood out from the others as a potential gold standard for flare prediction. The results were heterogeneous, and a lack of standardized data prevented us from identifying a powerful biomarker.

CONCLUSIONS

No powerful conclusions could be drawn from this systematic review due to a lack of standardized data. Efforts should be undertaken to optimize future research on potential SLE biomarkers to develop validated candidates. Thus, we propose a standardized pattern for future studies.

Systemic lupus erythematosus biomarkers: the challenging quest

SLE, a multisystem heterogeneous disease, is characterized by production of antibodies to cellular components, with activation of both the innate and the adaptive immune system. Decades of investigation of blood biomarkers has resulted in incremental improvements in the understanding of SLE. Owing to the heterogeneity of immune dysregulation, no single biomarker has emerged as a surrogate for disease activity or prediction of disease. Beyond identification of surrogate biomarkers, a multitude of clinical trials have sought to inhibit elevated SLE biomarkers for therapeutic benefit. Armed with new -omics technologies, the necessary yet daunting quest to identify better surrogate biomarkers and successful therapeutics for SLE continues with tenacity.

Pathways of impending disease flare in African-American systemic lupus erythematosus patients

Immune dysregulation in systemic lupus erythematosus (SLE) contributes to increased disease activity. African-American (AA) SLE patients have an increased prevalence of complications from disease flares and end-organ damage that leads to increased morbidity and early mortality. We previously reported alterations in inflammatory and regulatory immune mediator levels prior to disease flare in European American (EA) SLE patients. In the current study, we assessed baseline and follow-up plasma levels of 52 soluble mediators, including innate, adaptive, chemokine, and TNF superfamily members, in AA SLE patients who developed SELENA-SLEDAI defined flare 6 or 12 weeks after baseline assessment. These patients were compared to themselves during a comparable, clinically stable period (SNF, n = 18), or to demographically matched SLE patients without impending disease flare (NF, n = 13 per group). We observed significant (q < 0.05) alterations in 34 soluble mediators at baseline, with increased levels of both innate (IL-1α and type I interferons [IFN]) and adaptive cytokines (Th1-, Th2-, and Th17-type), as well as IFN-associated chemokines and soluble TNF superfamily members weeks before clinical disease flare. In contrast, stable SLE patients exhibited increased levels of the regulatory mediators IL-10 (q ≤ 0.0045) and TGF-β (q ≤ 0.0004). Because heterogeneous immune pathways were altered prior to clinical disease flare, we developed a soluble mediator score that encapsulates all mediators tested. This score is the sum of all log transformed, standardized soluble mediator levels assessed at baseline (pre-flare), weighted by their Spearman correlation coefficients for association with the SELENA-SLEDAI score at time of concurrent flare. While baseline SELENA-SLEDAI scores were similar between flare vs. NF (p = 0.7214) and SNF (p = 0.5387), the SMS was significantly higher in pre-flare SLE patients (Flare vs NF or SNF, p < 0.0001). By capturing alterations in the balance between inflammatory and regulatory mediators associated with SLE pathogenesis, the soluble mediator score approximates the immune status of SLE patients and provides a robust, predictive gauge of impending disease flare.

Genetic Variants in IL-12B and IL-27 in the Polish Patients with Systemic Lupus Erythematosus

To investigate the potential association between IL-12B and IL-27 gene polymorphisms and systemic lupus erythematosus (SLE), we performed a case-control study based on the Polish population. Patients with SLE and healthy individuals were examined for -6415 CTCTAA/GC (rs17860508) and +1188A/C (rs3212227) in IL-12B and -924A/G (rs153109) and 4730T/C (rs181206) in IL-27 gene polymorphisms using the high-resolution melting method, PCR-RFLP method and TaqMan SNP genotyping assay, respectively. An increased frequency of GC/GC genotype as well as GC allele of the IL-12B rs17860508 was found in patients with SLE, as compared with healthy subjects (P < 0.001). We did not find differences in genotype and allele frequencies of the IL-12B rs3212227 and IL-27 rs153109 and rs181206 variants between patients with SLE and controls. IL-27 haplotype rs181206C/rs153109G indicated higher risk for SLE (P = 0.002), whereas haplotype rs181206T/rs153109G indicated reduced risk for SLE (P = 0.005). The IL-12B rs3212227 A/C polymorphism was associated with the mean value of the platelets (PLT), urea and complement C3 level. Furthermore, IL-12B rs17860508 genetic variant showed correlation with PLT, prothrombin time, international normalized ratio and alkaline phosphatase. Our results revealed that IL-12B rs17860508 and IL-27 haplotype CG are genetic risk factors for SLE and that both IL-12B rs17860508 and rs3212227 predict disease phenotype.

Hyperactivation of the NLRP3 Inflammasome in Myeloid Cells Leads to Severe Organ Damage in Experimental Lupus

Systemic lupus erythematosus (SLE) is an autoimmune syndrome associated with severe organ damage resulting from the activation of immune cells. Recently, a role for caspase-1 in murine lupus was described, indicating an involvement of inflammasomes in the development of SLE. Among multiple inflammasomes identified, the NLRP3 inflammasome was connected to diverse diseases, including autoimmune encephalomyelitis. However, the function of NLRP3 in SLE development remains elusive. In this study, we explored the role of NLRP3 in the development of SLE using the pristane-induced experimental lupus model. It was discovered that more severe lupus-like syndrome developed in Nlrp3^-R258W mice carrying the gain-of-function mutation. Nlrp3^-R258W mutant mice exhibited significantly higher mortality upon pristane challenge. Moreover, prominent hypercellularity and interstitial nephritis were evident in the glomeruli of Nlrp3^-R258W mice. In addition, hyperactivation of the NLRP3 inflammasome in this mouse line resulted in proteinuria and mesangial destruction. Importantly, all of these phenotypes were largely attributed to the Nlrp3^-R258W mutation expressed in myeloid cells, because Cre recombinase-mediated depletion of this mutant from such cells rescued mice from experimental lupus. Taken together, our study demonstrates a critical role for NLRP3 in the development of SLE and suggests that modulating the inflammasome signal may help to control the inflammatory damage in autoimmune diseases, including lupus.

Exposure of Human CD4 T Cells to IL-12 Results in Enhanced TCR-Induced Cytokine Production, Altered TCR Signaling, and Increased Oxidative Metabolism

Human CD4 T cells are constantly exposed to IL-12 during infections and certain autoimmune disorders. The current paradigm is that IL-12 promotes the differentiation of naïve CD4 T cells into Th1 cells, but recent studies suggest IL-12 may play a more complex role in T cell biology. We examined if exposure to IL-12 alters human CD4 T cell responses to subsequent TCR stimulation. We found that IL-12 pretreatment increased TCR-induced IFN-γ, TNF-α, IL-13, IL-4 and IL-10 production. This suggests that prior exposure to IL-12 potentiates the TCR-induced release of a range of cytokines. We observed that IL-12 mediated its effects through both transcriptional and post-transcriptional mechanisms. IL-12 pretreatment increased the phosphorylation of AKT, p38 and LCK following TCR stimulation without altering other TCR signaling molecules, potentially mediating the increase in transcription of cytokines. In addition, the IL-12-mediated enhancement of cytokines that are not transcriptionally regulated was partially driven by increased oxidative metabolism. Our data uncover a novel function of IL-12 in human CD4 T cells; specifically, it enhances the release of a range of cytokines potentially by altering TCR signaling pathways and by enhancing oxidative metabolism.

Down-regulation of expression of retinoid acid-related orphan receptor C (RORC) in systemic lupus erythematosus

CONTEXT

Retinoic acid-related orphan receptor C (RORC), the key factor orchestrating the transcription of genes encoding interleukin 17, plays a critical role in the regulation of inflammatory responses.

OBJECTIVE

The objective of this study was to analyze the expression of RORC in the peripheral blood of patients with systemic lupus erythematosus (SLE) for a better understanding of the pathogenesis of SLE especially in relation to disease activity and clinical and biochemical findings.

METHODS

The study included 24 patients with SLE and a control group of 18 healthy gender- and age-matched individuals. Evaluation of the level of expression of RORC mRNA was performed by real-time polymerase chain reaction.

RESULTS

The results showed that patients with SLE had lower RORC gene expression levels compared with healthy subjects that were not correlated with disease activity. The down-regulation of RORC was significantly lower in patients with lupus nephritis in remission than active lupus nephritis and nonrenal patients.

CONCLUSIONS

The findings suggest that RORC plays a significant role in the dysregulated immune response associated with SLE. Deciphering the intricate regulatory network and the target genes of RORC will help unravel new specific treatments for SLE.

Cytokines and MicroRNAs as Candidate Biomarkers for Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease, with varied course and symptoms. Its etiology is very complex and not clearly understood. There is growing evidence of the important role of cytokines in SLE pathogenesis, as well as their utility as biomarkers and targets in new therapies. Other potential new SLE biomarkers are microRNAs. Recently, over one hundred different microRNAs have been demonstrated to have a significant impact on the immune system. Various alterations in these microRNAs, associated with disease pathogenesis, have been described. They influence the signaling pathways and functions of immune response cells. Here, we aim to review the emerging new data on SLE etiology and pathogenesis.

Dysfunction in macrophage toll-like receptor signaling caused by an inborn error of cationic amino acid transport

Amino acids, especially arginine, are vital for the well-being and activity of immune cells, and disruption of amino acid balance may weaken immunity and predispose to infectious and autoimmune diseases. We present here a model of an inborn aminoaciduria, lysinuric protein intolerance (LPI), in which a single mutation in y(+)LAT1 cationic amino acid transporter gene SLC7A7 leads to a multisystem disease characterized by immunological complications, life-threatening pulmonary alveolar proteinosis and nephropathy. Macrophages are suggested to play a central role in LPI in the development of these severe secondary symptoms. We thus studied the effect of the Finnish y(+)LAT1 mutation on monocyte-derived macrophages where toll-like receptors (TLRs) act as the key molecules in innate immune response against external pathogens. The function of LPI patient and control macrophage TLR signaling was examined by stimulating the TLR2/1, TLR4 and TLR9 pathways with their associated pathogen-associated molecular patterns. Downregulation in expression of TLR9, IRF7, IRF3 and IFNB1 and in secretion of IFN-α was detected, suggesting an impaired response to TLR9 stimulation. In addition, secretion of TNF-α, IL-12 and IL-1RA by TLR2/1 stimulation and IL-12 and IL-1RA by TLR4 stimulation was increased in the LPI patients. LPI macrophages secreted significantly less nitric oxide than control macrophages, whereas plasma concentrations of inflammatory chemokines CXCL8, CXCL9 and CXCL10 were elevated in the LPI patients. In conclusion, our results strengthen the relevance of macrophages in the pathogenesis of LPI and, furthermore, suggest that cationic amino acid transport plays an important role in the regulation of innate immune responses.

Proinflammatory adaptive cytokine and shed tumor necrosis factor receptor levels are elevated preceding systemic lupus erythematosus disease flare

OBJECTIVE

Systemic lupus erythematosus (SLE) is a multifaceted disease characterized by immune dysregulation and unpredictable disease activity. This study sought to evaluate the changes in plasma concentrations of soluble mediators that precede clinically defined disease flares.

METHODS

Fifty-two different soluble mediators, including cytokines, chemokines, and soluble receptors, were examined using validated multiplex bead-based or enzyme-linked immunosorbent assays in plasma from 28 European American patients with SLE who developed disease flare 6 or 12 weeks after a baseline assessment (preflare), 28 matched SLE patients without impending flare (nonflare), and 28 matched healthy controls. In a subset of 13 SLE patients, mediators within samples obtained preceding disease flare were compared with those within samples from the same individual obtained during a clinically stable period without flare.

RESULTS

Compared to SLE patients with clinically stable disease, SLE patients with impending flare had significant alterations (P ≤ 0.01) in the levels of 27 soluble mediators at baseline; specifically, the levels of proinflammatory mediators, including Th1-, Th2-, and Th17-type cytokines, were significantly higher several weeks before clinical flare. Baseline levels of regulatory cytokines, including interleukin-10 and transforming growth factor β, were higher in nonflare SLE patients, whereas baseline levels of soluble tumor necrosis factor receptor type I (TNFRI), TNFRII, Fas, FasL, and CD40L were significantly higher (P ≤ 0.002) in preflare SLE patients. The normalized and weighted combined soluble mediator score was significantly higher (P ≤ 0.0002) in preflare samples from SLE patients compared to samples from the same patients obtained during periods of stable disease.

CONCLUSION

The levels of proinflammatory adaptive cytokines and shed TNF receptors are elevated prior to disease flare, while the levels of regulatory mediators are elevated during periods of stable disease. Alterations in the balance between inflammatory and regulatory mediators may help identify patients at risk of disease flare and help decipher the pathogenic mechanisms of SLE.

Serum level of eight cytokines in Han Chinese patients with systemic lupus erythematosus using multiplex fluorescent microsphere method

AIM OF THE STUDY

To investigate the role of 8 cytokines and their correlation with clinical characteristics in systemic lupus erythematosus (SLE) in Han Chinese population by detecting their serum levels using the multiplex fluorescent microsphere method.

MATERIAL AND METHODS

Serum was separated from 79 patients with SLE and 40 healthy controls. The serum cytokine detection was conducted according to the instruction of MILLIPLEX MAP human cytokine detection kit on the Luminex liquid phase array platform with 0.01 pg/ml detectable level. The 8 cytokines were interferon α2 (IFN-α2), IFN-γ, interleukin 6 (IL-6), IL-8, IL-10, IFN-γ-inducible protein 10 (IP-10), tumor necrosis factor α (TNF-α) and IL-17. Variable data were in skewed distribution and were expressed with median (P25, P75). Mann-Whitney analysis was used in statistical analysis.

RESULTS

At the baseline level without any stimulus, the level of IP-10 expression was the highest among the 8 cytokines and the second highest was IL-8. The level of IL-17 was too low to be detected. The level of 7 cytokines was higher in SLE patients than in healthy controls (p < 0.01). The level of dsDNA antibody, C3, CRP, ESR and anti-nucleosome antibody was correlated with IL-10. Proteinuria was not correlated with any cytokine.

CONCLUSIONS

Eight cytokines were measured in our study, while not all of them were detected. The most important finding was the usefulness of IL-10 as a disease activity biomarker for Han Chinese patient with SLE. None of cytokines reflected kidney injury.

The association of cytokines with disease activity and damage scores in systemic lupus erythematosus patients

OBJECTIVE

The aim of this study was to explore the role of cytokines in the pathogenesis of SLE in a genetically homogeneous Caucasian SLE patient population.

METHODS

Serum levels of the following cytokines were determined by ELISA in SLE patients (diagnosed as per ACR diagnostic criteria): IL-1β, IL-10, IL-12p70 and TNF-α. Demographic data, disease activity as per the SLEDAI and damage scores (SLICC) at the 5-year follow-up were calculated.

RESULTS

Enhanced production of TNF-α, IL-1 and IL-10 were observed in SLE patients compared with controls. A strong positive correlation was seen between levels of IL-12p70 and IL-10. In addition, IL-10, TNF-α and IL-1 demonstrated a significant relationship with disease activity. Interestingly, elevated levels of IL-10 were observed in SLE patients with CNS involvement while patients with elevated levels of TNF-α were more likely to have renal involvement and sustain damage over the follow-up period. Additionally, the ratio of all cytokines assayed to IL-12p70 levels were significantly higher in SLE patients when compared with controls, with an association seen between damage accrual and the IL-1β/IL-12p70 ratio (r = 0.431, P = 0.003), IL-10/IL-12p70 ratio (r = 0.351, P = 0.018) and TNF-α/IL-12p70 ratio (r = 0.33, P = 0.028). When the respective ratios were analysed for organ-specific disease, significant differences were observed for the IL-1β/IL-12p70 ratio (0.79 vs 0.47, P = 0.036), IL-10/IL-12p70 ratio (4.29 vs 1.87, P = 0.018) and TNF-α/IL-12p70 ratio (7.49 vs 5.21, P = 0.018) with respect to renal involvement.

CONCLUSION

Increased levels of a number of immunomodulatory cytokines relative to IL-12p70 in this Caucasian SLE patient population are seen in patients with renal involvement and are associated with increased accrual of damage at the 5-year follow-up.

The applied basic research of systemic lupus erythematosus based on the biological omics

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by the production of autoantibodies directed against nuclear self-antigens and circulating immune complexes. This results in damages to various organs or systems, including skin, joints, kidneys and the central nervous system. Clinical manifestations of SLE could be diverse, including glomerulonephritis, dermatitis, thrombosis, vasculitis, seizures and arthritis. The complicated pathogenesis and varied clinical symptoms of SLE pose great challenges in the diagnosis and monitoring of this disease. Unfortunately, the etiological factors and pathogenesis of SLE are still not completely understood. It is noteworthy that recent advances in our understanding of the biological omics and emerging technologies have been providing new tools in the analyses of SLE, such as genomics, epigenomics, transcriptomics, proteomics, metabolomics and so on. In this article, we summarize our current knowledge in this field for a better understanding of the pathogenesis, diagnosis and treatment for SLE.

Monocytes from Irf5-/- mice have an intrinsic defect in their response to pristane-induced lupus

The transcription factor IFN regulatory factor (IRF)5 has been identified as a human systemic lupus erythematosus (SLE) susceptibility gene by numerous joint linkage and genome-wide association studies. Although IRF5 expression is significantly elevated in primary blood cells of SLE patients, it is not yet known how IRF5 contributes to SLE pathogenesis. Recent data from mouse models of lupus indicate a critical role for IRF5 in the production of pathogenic autoantibodies and the expression of Th2 cytokines and type I IFN. In the present study, we examined the mechanisms by which loss of Irf5 protects mice from pristane-induced lupus at early time points of disease development. We demonstrate that Irf5 is required for Ly6C(hi) monocyte trafficking to the peritoneal cavity, which is thought to be one of the initial key events leading to lupus pathogenesis in this model. Chemotaxis assays using peritoneal lavage from pristane-injected Irf5(+/+) and Irf5(-/-) littermates support an intrinsic defect in Irf5(-/-) monocytes. We found the expression of chemokine receptors CXCR4 and CCR2 to be dysregulated on Irf5(-/-) monocytes and less responsive to their respective ligands, CXCL12 and CCL2. Bone marrow reconstitution experiments further supported an intrinsic defect in Irf5(-/-) monocytes because Irf5(+/+) monocytes were preferentially recruited to the peritoneal cavity in response to pristane. Taken together, these findings demonstrate an intrinsic role for IRF5 in the response of monocytes to pristane and their recruitment to the primary site of inflammation that is thought to trigger lupus onset in this experimental model of SLE.

Octreotide for the treatment of systemic lupus erythematosus: clinical effects and an in vitro study on its therapeutic mechanism

Increased serum growth hormone (GH), together with high expression of growth hormone receptor on peripheral blood mononuclear cells (PBMCs), correlates with systemic lupus erythematosus (SLE) activity, suggesting that modulation of GH signaling may affect SLE activity. We explored the effects of octreotide (OCT), an analog of somatostatin that suppresses the release of GH, in SLE. The objectives of the study were to investigate effects of OCT on the proliferative capacity and cytokine expression of PBMCs from patients with SLE and to investigate therapeutic effects of OCT in patients with SLE. PBMCs from 13 active/inactive SLE patients and 11 controls were pretreated with or without GH and cultured with OCT. The proliferation of PBMCs was assessed by MTT assay and cytokines were quantified by ELISA. We compared the clinical response of 12 patients with SLE treated with OCT (100 µg twice daily) with 12 patients treated with prednisone over three months. OCT inhibited PBMC proliferation in a dose-dependent manner and decreased the secretion of interleukin-6 (IL-6), interleukin-10 (IL-10), and interferon-gamma (IFN-γ). Patients treated with OCT demonstrated improvements in SLEDAI, dsDNA titer, complement levels, and erythrocyte sedimentation rate (ESR). OCT inhibited PBMC proliferation and PBMC secretion of IL-6, IL-10 and IFN-γ stimulated by GH. Treatment of patients with OCT resulted in clinical improvement in SLE.

Cytokine imbalance in systemic lupus erythematosus: a study on northern Indian subjects

OBJECTIVE

The phenotype of systemic lupus erythematosus (SLE) in Asian Indians is more severe as compared with that in Caucasians. The reason is not clear. In this context, we studied serum levels of interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α), interleukin-4 (IL-4) and interlekin-10 (IL-10). Their interrelations and correlation with SLEDAI scores were evaluated.

MATERIALS AND METHODS

Forty patients with active SLE and 40 controls were studied. The mean SLEDAI score and anti-ds DNA level of the patients were 21.45 ± 8.61 and 176.68 ± 81.31 (IU/ml), respectively. Cytokines were estimated by enzyme-linked immunosorbent assay.

RESULTS

In controls, the levels of IFN-γ were highest, followed by TNF-α, IL-10 & IL-4. In patients, however, the levels of TNF-α were highest, followed by IFN-γ, IL-10 & IL-4. IL-10 and IL-4 correlated negatively, and IFN-γ and TNF-α correlated positively with the SLEDAI scores. As compared with controls, in patients, the mean values of TNF-α, IL-10 and TNF-α/IL-10 ratio were higher by 6.9, 2.9 and 2.3 times, respectively (p < 0.001). Significant positive correlation was found between these two cytokines in patients (r = 0.327, p < 0.05) but not in controls. The levels and ratio of IL-4 and IFN-γ were comparable between patients and controls. These two cytokines correlated negatively both in controls (r = -0.358, p < 0.05) and patients (r = -0.990, p < 0.001). The ratio of TNF-α/IL-4 was 4.2 times higher, and those of IFN-γ/IL-4 and IFN-γ/IL-10 were 1.89 and 3.40 times lower in patients as compared with controls. A positive correlation between IL-10 and IL-4 (r = 0.345, p < 0.05) and a negative correlation between IL-10 and IFN-γ (r = -0.382, p < 0.05) were observed only in patients.

CONCLUSION

This study showed a distinct profile of cytokine imbalance in patients with SLE from the northern plains of India. The levels, ratios and correlations of cytokines in patients suggested significant deviation from normal. Correlations of cytokines with SLEDAI scores indicated that TNF-α contributes significantly to the pathological manifestations of SLE in patients from the region. A detailed study is warranted.

Immunopathological roles of cytokines, chemokines, signaling molecules, and pattern-recognition receptors in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease with unknown etiology affecting more than one million individuals each year. It is characterized by B- and T-cell hyperactivity and by defects in the clearance of apoptotic cells and immune complexes. Understanding the complex process involved and the interaction between various cytokines, chemokines, signaling molecules, and pattern-recognition receptors (PRRs) in the immune pathways will provide valuable information on the development of novel therapeutic targets for treating SLE. In this paper, we review the immunopathological roles of novel cytokines, chemokines, signaling molecules, PRRs, and their interactions in immunoregulatory networks and suggest how their disturbances may implicate pathological conditions in SLE.

Inflammatory cytokines in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease of unknown origin affecting virtually all organ systems. Beyond genetic and environmental factors, cytokine imbalances contribute to immune dysfunction, trigger inflammation, and induce organ damage. The key cytokine that is involved in SLE pathogenesis is interferon alpha. Interferon secretion is induced by immune complexes and leads to upregulation of several inflammatory proteins, which account for the so-called IFN signature that can be found in the majority of SLE PBMCs. Additionally IL-6 and IFN-y as well as T-cell-derived cytokines like IL-17, IL-21, and IL-2 are dysregulated in SLE. The latter induce a T-cell phenotype that is characterized by enhanced B-cell help and enhanced secretion of proinflammatory cytokines but reduced induction of suppressive T cells and activation-induced cell death. This paper will focus on these cytokines and highlights pathophysiological approaches and therapeutic potential.

The multi-faceted influences of estrogen on lymphocytes: toward novel immuno-interventions strategies for autoimmunity management

Early studies of the immune system disclosed that, generally, females exhibit stronger responses to a variety of antigens than males. Perhaps as a result of this response, women are more prone to developing autoimmune diseases than men. Yet, the precise cellular and molecular mechanisms remain under investigation. Recently, interferon-gamma and the related pro-inflammatory interleukin-12 were found to be under effects of sex steroid hormones, with potential implications in regulating immune cells and autoimmune responses. In B lymphocytes, functional binding sites for estrogen receptors were identified in the promoter of the gene encoding activation-induced deaminase, an enzyme required for somatic hypermutation, and class-switch recombination. The observation that estrogen exerts direct impacts on antibody affinity-maturation provides a potential mechanism that could account for generating pathogenic high-affinity auto-antibodies. Further deciphering the multi-faceted influences of sex hormones on the responsiveness of immune cells could lead to novel therapeutic interventions for autoimmunity management.

IFN-α production by plasmacytoid dendritic cells stimulated with RNA-containing immune complexes is promoted by NK cells via MIP-1β and LFA-1

Several systemic autoimmune diseases display a prominent IFN signature. This is caused by a continuous IFN-α production by plasmacytoid dendritic cells (pDCs), which are activated by immune complexes (ICs) containing nucleic acid. The IFN-α production by pDCs stimulated with RNA-containing IC (RNA-IC) consisting of anti-RNP autoantibodies and U1 small nuclear ribonucleoprotein particles was recently shown to be inhibited by monocytes, but enhanced by NK cells. The inhibitory effect of monocytes was mediated by TNF-α, PGE(2), and reactive oxygen species, but the mechanisms for the NK cell-mediated increase in IFN-α production remained unclear. In this study, we investigated the mechanisms whereby NK cells increase the RNA-IC-induced IFN-α production by pDCs. Furthermore, NK cells from patients with systemic lupus erythematosus (SLE) were evaluated for their capacity to promote IFN-α production. We found that CD56(dim) NK cells could increase IFN-α production >1000-fold after RNA-IC activation, whereas CD56(bright) NK cells required costimulation by IL-12 and IL-18 to promote IFN-α production. NK cells produced MIP-1α, MIP-1β, RANTES, IFN-γ, and TNF-α via RNA-IC-mediated FcγRIIIA activation. The IFN-α production in pDCs was promoted by NK cells via MIP-1β secretion and LFA-mediated cell-cell contact. Moreover, NK cells from SLE patients displayed a reduced capacity to promote the RNA-IC-induced IFN-α production, which could be restored by exogenous IL-12 and IL-18. Thus, different molecular mechanisms can mediate the NK cell-dependent increase in IFN-α production by RNA-IC-stimulated pDCs, and our study suggests that the possibility to therapeutically target the NK-pDC axis in IFN-α-driven autoimmune diseases such as SLE should be investigated.

Interleukin 4 and STAT6 gene polymorphisms are associated with systemic lupus erythematosus in Chinese patients

An imbalance between T Helper 1 (TH1) and T Helper 2 (TH2) cytokine production is important for the pathogenesis of systemic lupus erythematosus (SLE). We aimed to investigate gene—gene associations of TH1 and TH2 cytokines genes in Chinese patients with SLE. Twenty single nucleotide polymorphisms (SNPs) in eight cytokines genes were genotyped in 110 SLE patients and 138 healthy controls in a case—control association study. The minor allelic frequencies of interleukin4(IL4) -590 T/C, -33 T/C, 9241C/G, and IL10 -592 A/C were significantly increased in SLE patients compared with those in controls (p < 0.05). None of the separate 20 SNPs showed significant association with SLE after Bonferroni correction. An IL4 haplotype -590C/-33C/9241G/14965C was significantly associated with SLE (odds ratio 3.7, 95% confidence interval [CI] 1.5—8.9, p = 0.004, Bonferroni-corrected p = 0.024). A borderline significant three-locus gene—gene interaction among IL4 9241 C/G, IL4 -33 T/C, signal transducer and activator of transcription 6, IL4-induced (STAT6) 2892 C/T was detected by a multifactor dimensionality reduction test (p = 0.051). However, the presence of two at-risk genotypes lead to increased risk of SLE for two-locus interaction using logistic regression method. The risk of SLE increased significantly when a subject has two at-risk genotypes for IL4 -590C and STAT6 2892C (odds ratio, 3.24, 95% CI 1.5—7.0, p = 0.003, Bonferroni-corrected p = 0.009), IL4 -33C and STAT6 2892C (odds ratio 3.06, 95% CI 1.4— 6.7, p = 0.005, Bonferroni-corrected p = 0.015), as well as IL4 9241G and STAT6 2892C (odds ratio 3.34, 95% CI 1.6—7.1, p = 0.002, Bonferroni-corrected p = 0.006). Further, plasma IL-4 concentrations were significantly lower in SLE patients than in healthy controls (1.59 + 3.53 versus 5.67 + 11.28 pg/ml, p = 0.042). These results indicated that IL4 and STAT6 genes might be involved in the etiology of SLE and potentially increased SLE risk through their interaction effect in Chinese patients.

Therapeutic strategies for SLE involving cytokines: mechanism-oriented therapies especially IFN-gamma targeting gene therapy

Systemic lupus erythematosus (SLE: lupus) is a chronic complicated autoimmune disease and pathogenesis is still unclear. However, key cytokines have been recognized. Interferon (IFN)-γ and also IFNalpha/beta are of particular importance. Depending on the concept that lupus is a helper T(Th)1 disease and that dendritic cells (DCs) determine the direction of lupus, balance shift of Th1/Th2 and immunogenic/tolerogenic DCs is reviewed for therapy. (IFN)-gamma- and IFN-alpha/beta-targeted (gene) therapies are introduced. These consist of Th1/Th2 balance shift and elimination of IFN-gamma and IFN-gamma-related cytokines such as (interleukin)IL-12 and IL-18. Other approaches include suppression of immunocompetent cells, normalization of abnormal T-cell function, costimulation blockade, B lymphocyte stimulator (Blys) blockade, and suppression of nephritic kidney inflammation. Moreover, balance shift of IFN-alpha/beta and tumor necrosis factor (TNF)-alpha together with regulatory T(Treg) cells are briefly introduced. Clinical application will be discussed.

Levels of transforming growth factor-beta are low in systemic lupus erythematosus patients with active disease

OBJECTIVE

Cytokines are central regulators of the immune response but the workings of this complex network in systemic lupus erythematosus (SLE) are not fully understood. We investigated a range of inflammatory and immune-modulating cytokines to determine their value as biomarkers for disease subsets in SLE.

METHODS

This was a cross-sectional study in 102 patients with SLE (87% women, disease duration 10.6 yrs). Circulating concentrations of interleukin 1β (IL-1β), IL-4, IL-6, IL-10, IL-12, IL-17, monocyte chemotactic protein 1 (MCP-1), macrophage inflammatory protein 1 (MIP-1α), MIP-1β, interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), and total transforming growth factor-β1 (TGF-β1) were related to disease activity (SLE Disease Activity Index; SLEDAI), lymphocyte subsets, autoantibody levels, accrued damage (Systemic Lupus International Collaborating Clinics/ACR Damage Index; SDI), and concomitant treatment.

RESULTS

Patients with SLE had lower levels of TGF-β1 (p = 0.01) and IL-1β (p = 0.0004) compared to controls. TGF-β1 levels were lower in patients with SLEDAI scores 1-10 and SDI > 3; and were correlated with CD4+, CD8+, and natural killer cell counts; and were independent of steroid or cytotoxic drug use. Treatment with cardiovascular drugs was associated with lower IL-12 levels. No consistent disease associations existed for the other cytokines investigated.

CONCLUSION

Lower TGF-β1 was the most consistent cytokine abnormality in patients with SLE. The associations with disease activity, lymphocyte subsets, and damage suggest that TGF-β1 may be a therapeutic target of interest in SLE.

Serum Levels and in Vitro Production of Th1- and Th2-Type Cytokines by Peripheral Blood Mononuclear Cells in Patients Suffering from Systemic Lupus Erythematosus

Th1-type and Th2-type cytokine profiles and adhesion molecules in the serum of patients suffering from systemic lupus erythematosus and the cytokine production by peripheral blood mononuclear cells (PBMC) were studied. Tumor necrosis factor-alpha (TNF-α), interferongamma (IFN-γ), interleukin-1β (IL-1β), IL-4, IL-10, IL-13, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) were measured using ELISA technique in the sera of 16 systemic lupus erythematosus patients without vasculitis (SLE), 30 SLE patients with vasculitis (LV), and in 18 healthy controls. The cytokines were also measured in the culture media of unstimulated, concana valin-A (Con-A) and phorbol-12-myristate-13-acetate (PMA) stimulated PBMC. TNF-α serum levels were significantly elevated in both SLE and LV patients and those of IL-1β in SLE patients. TNF-α was also significantly increased in SLE compared to LV patients. Serum levels of all three Th-2 cytokines were significantly elevated in both SLE and LV patients compared to healthy controls. Serum IFN-γ and Th2 cytokine levels were significantly increased in patients with more active disease. Both ICAM-1 and VCAM-1 were significantly increased in SLE patients and only VCAM-1 in LV patients. ICAM-1 showed a significant correlation with IL-1β, IFN-γ, IL-4 and IL-10 in both patient groups. In the SLE group VCAM-1 correlated significantly only with ICAM-1, but in the LV group only with IL-1β and IFN-γ. Compared to healthy controls, basal TNF-α and IL-4 production by unstimulated PBMC derived from SLE patients were significantly increased. Con-A-stimulated PBMC of both SLE groups produced significantly more IFN-γ, IL-4 and IL-13 than Con-A-stimulated control cells. Con-A-stimulated cells derived from LV patients produced much more INF-γ than cells from SLE patients. PMA strongly stimulated INFγ, TNFα and IL-13 production by cells derived from both SLE groups but had no effect on IL-4 production. In addition, it had little if any effect on the production of INFγ and IL-13 by PBMC derived from healthy donors. These findings suggest that the altered pattern of cytokine production by PBMC may play an important role in the SLE pathophysiology, accounting for differences in the clinical expression of the disease. The differences in adhesion molecules production and their correlation with cytokines suggest ICAM-1 and VCAM-1 as useful markers in SLE patients stratification.

Decreased expression of T lymphocyte co-stimulatory molecule CD26 on invariant natural killer T cells in systemic lupus erythematosus

CD26, a T cell co-stimulatory molecule and dipeptidyl peptidase IV for the degradation of interferon-gamma-induced chemokine, participates in multiple immunopathological roles in leukocyte homing and inflammation. Decreased circulating concentration of soluble (s)CD26 in patients with systemic lupus erythematosus (SLE), rheumatoid arthritis and murine model of arthritis and encephalomyelitis have been reported. In the present study, the plasma concentration of sCD26 and chemokines, and cell surface expression of CD26 on monocytes, CD4+T lymphocytes, CD8+T lymphocytes, CD19+B lymphocytes and invariant natural killer T (iNKT) lymphocytes were analyzed using ELISA and flow cytometry, respectively, in 23 SLE patients and 14 sex- and age-matched control subjects. Although there was no significant difference between plasma concentrations of soluble CD26 in SLE patients with controls (p > 0.05), there was significant elevated Th1 chemokines CXCL10 and CXCL9 but not Th2 chemokine CCL2, and down-regulation in iNKT lymphocytes number and cell surface expression of CD26 on CD4+T and iNKT lymphocytes of SLE patients compared with controls (all p < 0.05). Decreased circulating number of iNKT cells and CD26 on iNKT cells can be important for the immunopathogenesis by exacerbating Th1-related inflammation in SLE.

Association of estrogen receptor alpha gene polymorphisms with cytokine genes expression in systemic lupus erythematosus

AIM

To analyze the association of estrogen receptor alpha (OR alpha) gene polymorphisms with cytokine genes expression in patients with systemic lupus erythematosus (SLE) and controls.

METHODS

Genomic DNA was extracted and polymorphisms of XbaI, Ukrainian (XX, Xx, or xx genotype) and PvuII (PP, Pp, or pp) in intron 1 of OR alpha gene were detected by polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP) method. The messenger RNA (mRNA) levels of interleukin (IL)-10, IL-4, interferon (IFN)-gamma, and IL-2 were assessed by semiquantitative reverse transcription polymerase chain reaction (RT-PCR).

RESULTS

In patients with SLE with PpXx genotype, IL-10 and IL-4 mRNA expression was higher (P < 0.001 and P = 0.013, respectively), while in patients with SLE with Ppxx genotype IFN-gamma and IL-2 mRNA expression was lower than in controls (P < 0.001). There was no significant difference in mRNA expression of 4 cytokines among controls with various genotypes.

CONCLUSION

OR alpha gene polymorphism may be associated with the expression of IL-10, IL-4, IL-2, and IFN-gamma in patients with SLE.

No evidence for genetic association of interferon regulatory factor 3 in systemic lupus erythematosus

The aim of this study was to determine the potential role of three IRF3 gene polymorphisms (rs2304204, rs7251 and rs2304207) with systemic lupus erythematosus (SLE). Our study population consisted of 610 patients with SLE and 730 healthy controls. All individual were of Spanish Caucasian origin. The IRF3 polymorphisms were genotyped using a PCR system with pre-developed TaqMan allelic discrimination assay. No statistically significant differences were found when allele and genotype distribution of rs2304204, rs7251 and rs2304207 polymorphisms were compared between patients with SLE and controls [overall P values: rs7251, P = 0.06; rs2304204, P = 0.26 and rs2304207, P = 0.36, by chi-squared test on a 3 x 2 contingency table. Overall allelic P values: rs7251, P = 0.8, OR (95%CI) = 1.03 (0.87-1.22); rs2304204, P = 0.2, OR (95%CI) = 1.12 (0.93-1.34) and rs2304207, P = 0.8, OR (95%CI) = 1.02 (0.82-1.26)]. In addition, no evidence of association with haplotypes and clinical features of SLE was found. Our data suggest that the IRF3 polymorphisms do not appear to play a major role in the susceptibility or severity of SLE in a Spanish population.

Increased serum interleukin 17 in patients with systemic lupus erythematosus

Interleukin 17 (IL-17) is a Th17 cytokine associated with inflammation, autoimmunity and defense against some bacteria, it has been implicated in many chronic autoimmune diseases including psoriasis, multiple sclerosis and systemic sclerosis. However, whether IL-17 plays a role in the pathogenesis of systemic lupus erythematosus (SLE) remains unclear. In the present study, we aimed to investigate the serum IL-17 level in patients with SLE and it's associations with disease manifestations and activity. Fifty-seven patients with SLE and 30 healthy volunteers were recruited. Serum IL-17 levels were examined by enzyme linked immunosorbent assay (ELISA). Statistic analyzes were performed by SPSS 10.01. Results show that serum IL-17 levels were significantly elevated in SLE patients as compared with normal controls. Nevertheless, no associations of serum IL-17 level with clinical and laboratory parameters were found; no significant difference regarding serum IL-17 level between SLE patients with nephritis and those without nephritis was found; no significant difference was found between Less active SLE and More active SLE; Correlation analysis between serum IL-17 levels and SLEDAI showed no association. Taken together, our results indicate increased serum IL-17 levels in SLE patients, suggesting that this cytokine may trigger the inflammatory process in SLE. However, no associations of serum IL-17 level with disease manifestations were found. Therefore, further studies are required to confirm this preliminary data.

Cytokines in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by the production of autoantibodies that can form immune complexes and deposit in tissues, causing inflammation and organ damage. There is evidence that interferons and some interleukins can have an active role in the pathogenesis of SLE and can contribute significantly to the immune imbalance in the disease, whereas the role of some cytokines (such as TNF) is still debated. This review discusses the activity of several cytokines in SLE, their effects on the immune cells in relation to the disease pathogenesis, and the promise and limitations of cytokine-based therapies in clinical trials for lupus patients.