Interferon-α regulates abnormally increased expression of RSAD2 in Th17 and Tfh cells in systemic lupus erythematosus patients

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that often involves abnormal activation of regulatory IFN genes and regulation of B cells by CD4⁺ T cells. Radical S-adenosyl methionine domain containing 2 (RSAD2) is a viral suppressor protein regulated by type I IFN, and it has been proven to play an important regulatory role in SLE. However, the mechanism by which RSAD2 participates in the pathogenesis of SLE is unclear. In this study, we observed higher expression levels of RSAD2 in CD4⁺ T-cell subsets from the peripheral blood of SLE patients than in those from healthy controls by bioinformatics analysis and validation experiments. We analyzed the expression of RSAD2 in CD4⁺ T cells of patients with SLE and other autoimmune diseases. In addition, we found that the expression of RSAD2 in CD4⁺ T cells might be regulated by IFN-α, and RSAD2 significantly affected the differentiation of Th17 cells and T follicular helper (Tfh) cells. Our findings underlined that RSAD2 may promote B-cell activation by promoting the differentiation of Th17 and Tfh cells in SLE patients, a process that is regulated by IFN-α.     

Restoring regulation – IL-2 therapy in systemic lupus erythematosus

Introduction: The pathogenesis of systemic lupus erythematosus (SLE) involves an acquired deficiency of the cytokine IL-2, an essential growth and survival factor for regulatory T cells (Treg), which play an important role in the control of autoimmunity in SLE. In contrast to currently available therapies that broadly suppress the immune system, low-dose IL-2 therapy in SLE aims to compensate the pre-existing IL-2 deficiency and thus to restore a physiological state, where Treg can regain their ability to efficiently counteract autoimmunity.

Areas covered: Here we summarize key findings that led to the development of this novel therapeutic concept and will highlight the key rationales for the clinical translation of low-dose IL-2 therapy in SLE.

Expert commentary: The concept of low-dose IL-2 therapy in SLE has evolved from pathophysiological findings and thus can be considered a selective biological treatment strategy in SLE. Preliminary results from phase I/II studies are promising by proving selective Treg expansion and by providing first evidence for the clinical efficacy of low-dose IL-2 therapy in SLE.     

The expression of PD-1 and level of CXCL10 in patients with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is known tobe a chronic and complicated rheumatic diseasewith an autoimmune etiology.SLEis also a proto-type of autoimmune disease due to a substantialoverlapinits clinical symptoms withother autoim-mune diseases . The immune systemof SLElosesbalance of auto-tolerance ,in which lymphocytesare activated excessively,contributingto SLE de-velopment .It has been well established that effi-cient T cell-mediated immune responses requirenot only the TCR-mediat…     

Clinical and serological manifestations associated with interferon-α levels in childhood-onset systemic lupus erythematosus

OBJECTIVE:

To determine the serum levels of interferon alpha in childhood-onset systemic lupus erythematosus patients, their first-degree relatives and healthy controls and to evaluate the associations between serum interferon alpha and disease activity, laboratory findings and treatment features.

METHODS:

We screened consecutive childhood-onset systemic lupus erythematosus patients in a longitudinal cohort at the pediatric rheumatology unit of the State University of Campinas between 2009 and 2010. All patients demonstrated disease onset before the age of 16. Disease status was assessed according to the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) and Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI). Interferon alpha levels were measured using an enzyme-linked immunoabsorbent assay.

RESULTS:

We included 57 childhood-onset systemic lupus erythematosus patients (mean age 17.33±4.50), 64 first-degree relatives (mean age 39.95±5.66), and 57 healthy (mean age 19.30±4.97) controls. Serum interferon alpha levels were significantly increased in childhood-onset systemic lupus erythematosus patients compared to their first-degree relatives and healthy controls. Interferon alpha levels were significantly increased in patients with positive dsDNA antibodies, patients with cutaneous vasculitis, patients with new malar rash and patients who were not receiving medication. Interferon alpha levels correlated with C3 levels and systemic lupus erythematosus Disease Activity Index scores. In addition, we observed an inverse correlation between patient age and interferon alpha levels.

CONCLUSION:

Interferon alpha may play a role in the pathogenesis of childhood-onset systemic lupus erythematosus, especially in cutaneous manifestations and dsDNA antibody formation. The observation that interferon alpha levels are increased in patients who are not taking medication should be investigated in longitudinal studies to determine whether elevated interferon alpha levels may predict systemic lupus erythematosus flares.     

Regulatory effect of IL-38 on NF-κB pathway in systemic lupus erythematosus

BackgroundIL-38 is a newly identified cytokine that exhibits immunosuppression effects. However, there are few studies focusing on the effects and mechanisms of IL-38 in the systemic lupus erythematosus (SLE).AimWe investigated the effects and mechanisms of IL-38 on NF-κB signaling pathway in SLE.MethodsLevels of IL-38, IL-36R, IL-1RAcP, IKKα/β, NF-κB, TNF-α and anti-dsDNA antibody levels in peripheral blood of SLE patients, and in peripheral blood and kidney tissues of MRL/lpr mice, were examined with real-time PCR, ELISA, Western blot and immunohistochemistry. Pathological changes of kidney were detected with PAS staining. Recombinant human IL-38 protein and IL-38 siRNA were used to intervene the PBMCs of SLE patients and MRL/lpr mice.ResultsThe mRNA and protein levels of IL-38 in peripheral blood of SLE patients decreased and were positively correlated. The mRNA and protein levels of IKKα/β, NF-κB, and TNF-α increased, especially in patients with active SLE. There was a negative correlation between IL-38 and the levels of IKKα/β, NF-κB and TNF-α in SLE patients. In vitro experiments showed that the levels of IKKα/β, NF-κB and TNF-α, and anti-dsDNA antibodies decreased in PBMCs of SLE patients after treatment with human recombinant IL-38 protein. These effects were reversed after IL-38 siRNA intervention. Consistent results were obtained on IL-38, IKKα/β, NF-κB, and TNF-α in MRL/lpr lupus mice after treatment with IL-38 protein or IL-38 shRNA. Additionally, kidney function (reflected by creatinine and blood urea nitrogen), anti-dsDNA antibody, complement C3, and urinary protein levels decreased after treatment with IL-38 protein but increased after IL-38 shRNA treatment. PAS staining showed IL-38 protein treatment induced mild hyperplasia of glomerular mesangial cells and a small amount of lymphocyte infiltration. However, these were aggravated after IL-38 shRNA treatment.ConclusionIL-38 may be involved in the occurrence and development of SLE by regulating the NF-κB signaling pathway. This study only discussed the relationship between IL-38 and NF-κB, and more biological functions of IL-38 need to be further studied.     

IL-22 and IL-20 are key mediators of the epidermal alterations in psoriasis while IL-17 and IFN-γ are not

Psoriasis is a common chronic skin disease with a largely unknown pathogenesis. We demonstrate here that transgenic over-expression of interleukin (IL)-22 in mice resulted in neonatal mortality and psoriasis-like skin alterations including acanthosis and hypogranularity. This cutaneous phenotype may be caused by the direct influence of IL-22 on keratinocytes, since this cytokine did not affect skin fibroblasts, endothelial cells, melanocytes, or adipocytes. The comparison of cytokines with hypothesized roles in psoriasis pathogenesis determined that neither interferon (IFN)-γ nor IL-17, but only IL-22 and, with lower potency, IL-20 caused psoriasis-like morphological changes in a three-dimensional human epidermis model. These changes were associated with inhibited keratinocyte terminal differentiation and with STAT3 upregulation. The IL-22 effect on differentiation-regulating genes was STAT3-dependent. In contrast to IL-22 and IL-20, IFN-γ and IL-17 strongly induced T-cell and neutrophilic granulocyte-attracting chemokines, respectively. Tumor necrosis factor-α potently induced diverse chemokines and additionally enhanced the expression of IL-22 receptor pathway elements and amplified some IL-22 effects. This study suggests that different cytokines are players in the psoriasis pathogenesis although only the IL-10 family members IL-22 and IL-20 directly cause the characteristic epidermal alterations. Kerstin Wolk and Harald S. Haugen equally contributed to this work.     

Management of immune cytopenias in patients with systemic lupus erythematosus — Old and new

There are various immune cytopenias associated with systemic lupus erythematosus (SLE). The most common one is anemia; however, there are different etiologies for the anemia caused by SLE. Anemia could be due to chronic disease, secondary to renal insufficiency, blood loss, drug induced or autoimmune hemolysis. There are other very rare causes of anemia secondary to SLE which include red cell aplasia, aplastic anemia, and microangiopathic hemolytic anemia. Treatment of the anemia would be according to the cause. Leukopenia, neutropenia, and lymphopenia are hematologic complications associated with SLE, and in majority of cases no treatment is required. Thrombocytopenia is one of the complications of SLE and is usually treated by steroids. However, there are significant numbers of patients which will either not respond to or relapse after treatment. This article summarizes immune cytopenias seen in patients with SLE, and it also discusses management of these cytopenias.     

Simultaneous detection of cell-secreted TNF-α and IFN-γ using micropatterned aptamer-modified electrodes

Cellular production of such cytokines as interferon (IFN)-γ and tumor necrosis factor (TNF)-α is used to determine disease-specific immune responses and may be used to diagnose infectious diseases such as tuberculosis. In this paper, we describe the development of micropatterned electrodes functionalized with electroactive aptamers for multiplexed detection of immune-cell-produced cytokines. A sequence of electrode deprotection and aptamer incubation steps were used to assemble anti-IFN-γ DNA aptamers and anti-TNF-α RNA aptamers on individually addressable half-ring electrodes. Aptamer molecules were thiolated for assembly on gold and were functionalized with methylene blue redox reporter for electrochemical signal transduction. Specificity of individual sensors to the correct cytokine species was confirmed by exposure to recombinant cytokines. For cell detection experiments, electrode arrays were integrated into microfluidic devices and incubated with immune cells. Design of the surface was such that a small group of ～400 cells attached in the circular adhesion sites surrounded by half-ring electrodes sensing IFN-γ and TNF-α. The microdevice consisted of two parallel microfluidic channels, each channel containing four cell capture/sensing sites. Upon mitogenic activation, secreted IFN-γ and TNF-α molecules were monitored by performing square wave voltammetry (SWV) at different time points at individually addressable electrodes. This biosensing platform was used to analyze the quantity and rate of cytokine release from primary T cells and a monocyte cell line. Upon further development of this platform may be enhanced to enable detection of larger number of cytokines and used to correlate the levels and dynamics of cytokine release in immune cells to diagnosis and treatment of infectious diseases.     

IFN-β, IFN-γ, and TNF-α decrease erythrophagocytosis by human monocytes independent of SIRP-α or SHP-1 expression

Background: Many cases of autoimmune hemolytic anemia have been reported after viral infection. Phagocyte activation and accompanying erythrophagocytosis are thought to result from proinflammatory cytokines released during viral infection. SIRP-α (signal regulatory protein-α), a receptor expressed on phagocytes, inhibits phagocytosis when bound to CD47 on the erythrocyte membrane. Ligation with CD47 results in SHP-1 recruitment to SIRP-α and dephosphorylation of specific downstream substrates involved in phagocytosis. SIRP-α ligation by CD47 may be inhibited by proinflammatory cytokines.

Objectives: The aim of this work was to evaluate the effect of IFN-β, IFN-γ, and TNF-α on erythrophagocytosis and assess the effect on expression of SIRP-α and SHP-1 in human monocytes.

Materials and methods: Monocytes were cultured ex vivo with IFN-β or IFN-γ/TNF-α. Erythrophagocytosis was determined by flow cytometry. SIRP-α and SHP-1 gene expression was determined by real time-PCR, while SIRP-α and SHP-1 protein expression was determined by western blot.

Results: Erythrophagocytosis by monocytes significantly decreased after treatment with either IFN-β or IFN-γ/TNF-α. Monocytes cultured with IFN-γ/TNF-α showed increased SIRP-α gene and protein expression and SHP-1 gene expression. Monocytes cultured with IFN-β did not show any alteration in SIRP-α or SHP-1 expression.

Conclusion: We conclude that IFN-β and IFN-γ/TNF-α decrease erythrophagocytosis by human monocytes in vitro, and this effect does not apparently require an increase in SIRP-α or SHP-1 expression.     

SJSZ glycoprotein (38?kDa) modulates expression of IL-2, IL-12, and IFN-γ in cyclophosphamide-induced Balb/c

Objective

Cyclophosphamide (CTX) often results in immunosuppression and cytotoxic effects. The object of this study was to understand whether Styrax japonica Siebold et al. Zuccarini (SJSZ) glycoprotein prevents immunosuppression in CTX-induced Balb/c.

Methods

The mice were injected intraperitoneally with CTX (80?mg/kg, BW) for 1?week in the presence or absence of the SJSZ glycoprotein, and divided into five groups. Weights of the spleen and thymus, phagocytic macrophages, proliferation of splenocytes and thymocytes ([³H]-thymidine incorporation and expression of PCNA), natural killer (NK) cytotoxicity [MTT assay, perforin, and granzyme B], and cytokines [interleukin (IL)-2, IL-12, and interferon (IFN)-γ] were evaluated using radioactivity, biochemical reactions, immunoblot analysis, and qRT-PCR. Activity of antioxidant enzymes [superoxide dismutase (SOD), glutathione dismutase (GPx) and catalase (CAT)] was also assessed.

Results

The results revealed that while the parameters assessed decreased with treatment with CTX alone, SJSZ glycoprotein (10?mg/kg, BW) in the presence of CTX significantly normalized the weights of spleen and thymus, the phagocytic effect of peritoneal macrophages, the activity of antioxidant enzymes, proliferation (splenocytes and thymocytes), NK cell cytotoxicity, and expression of IL-2, IL-12, and IFN-γ.

Conclusion

SJSZ glycoprotein can normalize activity of anti-oxidative enzymes and immune-related factors.     

Effect of IFN-γ and IL-4 levels on the expression of Fas and Bcl-2 in peripheral blood lymphocytes in hemodialysis patients

To study the correlation between the levels of IFN-γ and IL-4 and the expression of Fas and Bcl-2 in peripheral blood lymphocytes (PBL) in hemodialysis patients, the indirect immune fluorescein labeling method of flow cytometry and solid sandwich enzyme-linked immunosorbent assay were performed for detecting the expression of Fas and Bcl-2 in PBL and the levels of IFN-γ and IL-4 in the serum of 30 hemodialysis patients, respectively. It was found that the expression of Fas in PBL and the level of IL-4 in the serum of hemodialysis patients were significantly higher (P < 0.01), whereas Bcl-2 in PBL and IFN-γ in the serum were significantly lower (P < 0.01) than those of the normal controls. According to statistical analysis, the expression of Fas in PBL had a negative correlation with the level of IFN-γ, but a positive correlation with IL-4 in the serum of hemodialysis patients. Contrarily, the expression of Bcl-2 had a positive correlation with IFN-γ, but a negative correlation with IL-4 in the serum of hemodialysis patients. These results suggest that hemodialysis patients have a suppressed secretion of Th1-associated cytokine IFN-γ, but an increased secretion of Th2-associated cytokines IL-4, and these two aspects may play an important role in the abnormal apoptosis of PBL and its accompanying immune deficiency.     

Role of Fcγ receptor IIb polymorphism in the genetic background of systemic lupus erythematosus: Insights from Asia

FCGR2B codes for an inhibitory receptor expressed in B cells and monocytes. Polymorphisms of Fcgr2b in mice have been shown to be associated with autoimmune diseases including systemic lupus erythematosus (SLE) and targeted disruption of Fcgr2b renders mice susceptible to induced or spontaneous autoimmunity, depending on the genetic background. Polymorphism screening of FCGR2B has been hampered by the complexity and extreme homology among FCGR family members. We established a specific genotyping system, detected a SNP that changes position 232 amino acid in the transmembrane region from Ile to Thr and found a significant association of 232Thr with SLE in the Japanese, Thai and Chinese populations. In contrast, promoter polymorphism of FCGR2B, but not Ile232Thr, was shown to be associated with SLE in Caucasians. Linkage disequilibrium was observed among FCGR2A, 2B, 3A and 3B genes with varying degrees, but in the Asian populations, each of FCGR2B, 3A and 3B genes was suggested to contribute to the susceptibility to SLE. These results indicate that FCGR2B is a susceptibility gene to SLE in the context of a genetic background, both in humans and mice.     

TNF-α and IL-1β sensitize human MSC for IFN-γ signaling and enhance neutrophil recruitment

During inflammatory processes, tissue environmental cues are influencing the immunoregulatory properties of tissue-resident mesenchymal stem/stromal cells (MSC). In this study, we elucidated one of the molecular and cellular responses of human MSC exposed to combinations of inflammatory cytokines. We showed that during multi-cytokine priming by TNF-α, IL-1β, and IFN-γ, IL-1β further augmented the well-established immunoregulatory activity induced by TNF-α/IFN-γ. On the molecular level, TNF-α and IL-1β enhanced the expression of IFN-γ receptor (IFN-γR) via NF 'kappa-light-chain-enhancer' of activated B-cells (NF-κΒ) signaling. In turn, enhanced responsiveness to IFN-γ stimulation activated STAT5 and p38-MAPK signaling. This molecular feedback resulted in an increased IL-8 release and augmented recruitment of polymorphonuclear granulocytes (PMN). Our study suggests the possibility that responses of MSC to multi-cytokine priming regimens may be exploited therapeutically to fine-tune inflammatory activity in tissues. This study elucidates molecular mechanisms underlying the immunological priming of mesenchymal stromal cells (MSC) and their interaction with neutrophils.     

Detection of circulating soluble CD28 in patients with systemic lupus erythematosus, primary Sjögren's syndrome and systemic sclerosis

The aim of this study was to evaluate the presence and the role of the serum soluble costimulatory molecule CD28 in patients with systemic lupus erythematosus (SLE), primary Sjögren's syndrome (SS), and systemic sclerosis (SSc). Soluble CD28 concentration was determined by ELISA in 45 patients with SLE, 45 patients with primary SS, 30 patients with SSc, and 45 healthy subjects. We also evaluated CD28 mRNA expression by semiquantitative RT‐PCR, and the biological activity of recombinant soluble CD28 on T lymphocyte activity. Concentrations of soluble CD28 were significantly higher in patients with SLE, primary SS and SSc than in healthy subjects. Soluble CD28 concentrations were higher in patients with systemic primary SS than in patients with glandular‐limited primary SS. PCR analysis suggested that soluble CD28 resulted from the shedding of the membrane form. In vitro assay revealed that soluble CD28 inhibits the anti‐CD3 mAb induced T cell proliferation. Soluble CD28, which modulates the proliferation of T lymphocytes, could be associated with disease severity in patients with autoimmune disease, especially primary SS. These results suggest that soluble CD28 could play an important role in the regulation of autoimmune diseases.     

Inflammatory cytokines IFN-γ, IL-4, IL-13 and TNF-α alterations in schistosomiasis: a meta-analysis

Cytokines play an important role in the immunological pathogenesis of schistosomiasis. Schistosomiasis would be associated with an imbalance in inflammatory cytokines that leads to a decrease of T helper (Th) 1 and an increase of Th2 cytokine secretion. Corresponding data so far have been inconsistent, so we performed a meta-analysis to assess whether cytokine alterations were risk factors for schistosomiasis progression. We searched MEDLINE, EMBASE, and CNKI databases for literatures including abstracts, reviews, and reference lists. Our studies included assessment of cytokine concentrations in vivo plasma or serum and secretion of cytokines in vitro by peripheral blood leukocytes from schistosomiasis patients or infected individuals with schistosome. The prototypic Th1 and Th2 cytokines IFN-γ and interleukin (IL)-4 were assessed as well as IL-13 and tumor necrosis factor-alpha (TNF-α). The results implied that an increase occurs in TNF-α and IL-4 with schistosomiasis progression.