Elevated circulating CD4+ ICOS+ Foxp3+ T cells contribute to overproduction of IL-10 and are correlated with disease severity in patients with systemic lupus erythematosus

Lupus susceptibility gene Pbx1 controls the development, stability, and function of regulatory T cells via Rtkn2 expression

The maintenance of regulatory T (Treg) cells critically prevents autoimmunity. Pre-B cell leukemia transcription factor 1 (Pbx1) variants are associated with lupus susceptibility, particularly through the expression of a dominant negative isoform Pbx1-d in CD4+ T cells. Pbx1-d overexpression impaired Treg cell homeostasis and promoted inflammatory CD4+ T cells. Here, we showed a high expression of Pbx1 in human and murine Treg cells, which is decreased in lupus patients and mice. Pbx1 deficiency or Pbx1-d overexpression reduced the number, stability, and suppressive activity of Treg cells, which increased murine responses to immunization and autoimmune induction. Mechanistically, Pbx1 deficiency altered the expression of genes implicated in cell cycle and apoptosis in Treg cells. Intriguingly, Rtkn2, a Rho-GTPase previously associated with Treg homeostasis, was directly transactivated by Pbx1. Our results suggest that the maintenance of Treg cell homeostasis and stability by Pbx1 through cell cycle progression prevent the expansion of inflammatory T cells that otherwise exacerbates lupus progression in the hosts.

Association of IL10RA, IL10RB, and IL22RA Polymorphisms/Haplotypes with Susceptibility to and Clinical Manifestations of SLE

Systemic lupus erythematosus (SLE) is characterized by an imbalance between proinflammatory and anti-inflammatory mediators. Single-nucleotide polymorphisms (SNPs) in genes coding IL10RA, IL10RB, and IL22RA could affect their expression or function and disrupt immune homeostasis. We aimed to analyze the associations of IL10RA, IL10RB, and IL22RA polymorphisms/haplotypes with patients' susceptibility to and clinical manifestations of SLE. Our study included 103 SLE patients and 99 healthy controls. The genotypes of the selected polymorphisms within IL10RA (rs10892202, rs4252270, rs3135932, rs2228055, rs2229113, and rs9610), IL10RB (rs999788, rs2834167, and rs1058867), and IL22RA (rs3795299 and rs16829204) genes were determined by TaqMan^® Assays. IL10RB rs1058867 G allele carriers were significantly more frequent among the controls than among the SLE patients (76.8% vs. 61.2%; p = 0.017, OR = 0.477, 95% CI: 0.258-0.879). The IL10RB CAA haplotype was more frequent among the SLE patients than in the control group (42.7% vs. 30.7%; p = 0.027). The IL22RA rs3795299 C allele and rs16829204 CC genotype were associated with Hashimoto thyroiditis in the SLE patients (n = 103; p = 0.002 and p = 0.026, respectively), and in all the included participants (n = 202, p < 0.000 and p = 0.007, respectively), and the IL22RA CC haplotype was more frequent in the SLE patients with Hashimoto thyroiditis (p = 0.047) and in the overall participants with Hashimoto thyroiditis (n = 32, p = 0.004). The IL10RA, IL10RB, and IL22RA polymorphisms/haplotypes could be associated with SLE susceptibility and various clinical manifestations, and the IL22RA CC haplotype could be associated with Hashimoto thyroiditis.

Regulatory T cells in psoriatic arthritis: an IL-17A-producing, Foxp3intCD161 + RORγt + ICOS + phenotype, that associates with the presence of ADAMTSL5 autoantibodies

In psoriatic arthritis (PsA), predisposing class I HLA alleles, the presence of synovial clonally proliferated CD8 + T cells and autoantibodies all point towards the loss of immune tolerance. However, the key mechanisms that lead to immune dysregulation are not fully understood. In other types of inflammatory arthritis, T regulatory cell (Treg) dysfunction and plasticity at sites of inflammation were suggested to negatively affect peripheral tolerance. We here addressed if Treg variances associate with psoriatic disease. We collected clinical data, sera and peripheral blood mononuclear cells from 13 healthy controls, 21 psoriasis and 21 PsA patients. In addition, we obtained synovial fluid mononuclear cells from 6 PsA patients. We studied characteristics of CD4 + CD25 + CD127^loFoxp3 + Tregs by flow cytometry and used ELISA to quantify antibodies against ADAMTSL5, a recently discovered autoantigen in psoriatic disease. In comparison with their circulating counterparts, Tregs from inflamed joints express increased levels of ICOS, CTLA-4 and TIGIT. Furthermore, synovial fluid-derived Tregs have a distinct phenotype, characterized by IL-17A production and upregulation of CD161 and RORγt. We identified a subset of Tregs with intermediate Foxp3 expression as the major cytokine producer. Furthermore, ICOS + Tregs associate with PsA disease activity as measured by PASDAS. Lastly, we observed that presence of the Foxp3^int Tregs associates with an increased abundance of anti-ADAMTSL5 autoantibodies. Tregs derived from the inflammatory environment of inflamed PsA joints exhibit a distinct phenotype, which associates with loss of peripheral immune tolerance in psoriatic disease.

Factors mediating cancer risk in systemic lupus erythematosus

Patients with systemic lupus erythematosus (SLE) are at an elevated risk for certain cancers compared to the population at large. Cancers seen at higher rates in the SLE population include hematologic malignancies, such as non-Hodgkin lymphoma, and cancers of the lung and thyroid. SLE patients also have a decreased risk for certain malignancies, such as breast cancer, melanoma, and prostate cancer. We review the literature on risk factors for malignancy in patients with SLE and discuss the exogenous and innate factors that are thought to contribute to the unique pattern of cancer risk observed in this patient population. These risk factors are important for providers of SLE patients to understand in order to maintain high clinical suspicion and detect malignancy as soon as possible. Further research is needed to determine the most effective guidelines on counseling patients on cancer screening and prevention.

Inducible Costimulator-C-X-C Motif Chemokine Receptor 3 Signaling is Involved in Chronic Obstructive Pulmonary Disease Pathogenesis

Background

The role of inducible costimulator (ICOS) signaling in chronic obstructive pulmonary disease (COPD) has not been fully elucidated.

Methods

We compared the percentages of ICOS⁺ T cells and ICOS⁺ regulatory T (Treg) cells in CD4⁺ T cells and CD4⁺CD25⁺FOXP3⁺ Tregs, respectively, in the peripheral blood of smokers with or without COPD to those in healthy controls. We further characterized their phenotypes using flow cytometry. To investigate the influence of ICOS signaling on C-X-C motif chemokine receptor 3 (CXCR3) expression in COPD, we evaluated the expression levels of ICOS and CXCR3 in vivo and in vitro.

Results

ICOS expression was elevated on peripheral CD4⁺ T cells and CD4⁺ Tregs of COPD patients, which positively correlated with the severity of lung function impairment in patients with stable COPD (SCOPD), but not in patients with acute exacerbation of COPD (AECOPD). ICOS⁺CD4⁺ Tregs in patients with SCOPD expressed higher levels of coinhibitors, programmed cell death protein 1 (PD-1) and T-cell immunoreceptor with Ig and ITIM domains (TIGIT), than ICOS⁻CD4⁺ Tregs, whereas ICOS⁺CD4⁺ T cells mostly exhibited a central memory (CD45RA⁻CCR7⁺) or effector memory (CD45RA⁻CCR7⁻) phenotype, ensuring their superior potential to respond potently and quickly to pathogen invasion. Furthermore, increased percentages of CXCR3⁺CD4⁺ T cells and CXCR3⁺CD4⁺ Tregs were observed in the peripheral blood of patients with SCOPD, and the expression level of CXCR3 was higher in ICOS⁺CD4⁺ T cells than in ICOS⁻CD4⁺ T cells. The percentage of CXCR3⁺CD4⁺ T cells was even higher in the bronchoalveolar lavage fluid than in matched peripheral blood in SCOPD group. Lastly, in vitro experiments showed that ICOS induced CXCR3 expression on CD4⁺ T cells.

Conclusions

ICOS signaling is upregulated in COPD, which induces CXCR3 expression. This may contribute to increased numbers of CXCR3⁺ Th1 cells in the lungs of patients with COPD, causing inflammation and tissue damage.

Activation Markers on B and T Cells and Immune Checkpoints in Autoimmune Rheumatic Diseases

In addition to identifying the major B- and T-cell subpopulations involved in autoimmune rheumatic diseases (ARDs), in recent years special attention has been paid to studying the expression of their activation markers and immune checkpoints (ICPs). The activation markers on B and T cells are a consequence of the immune response, and these molecules are considered as sensitive specific markers of ARD activity and as promising targets for immunotherapy. ICPs regulate the activation of the immune response by preventing the initiation of autoimmune processes, and they modulate it by reducing immune cell-induced organ and tissue damage. The article considers the possible correlation of ICPs with the activity of ARDs, the efficacy of specific ARD treatments, and the prospects for the use of activation molecules and activation/blocking ICPs for the treatment of ARDs.

Increased Levels of ICOS and ICOSL Are Associated to Pulmonary Arterial Hypertension in Patients Affected by Connective Tissue Diseases

Background: Pulmonary hypertension (PH) is a life-threatening complication of connective tissue diseases (CTD); in this study, we aimed at investigating the potential role of inducible co-stimulator (ICOS) and its ligand (ICOS-L) as biomarkers of PH in CTD. Materials and Methods: We recruited 109 patients: 84 CTD patients, 13 patients with CTD complicated by pulmonary arterial hypertension (PAH), and 12 subjects with PAH alone. All recruited patients underwent a complete clinical and instrumental assessment along with quantitative measurement of serum ICOS and ICOS-L. Results: Independently of the underlying cause, patients with PAH were older and had a lower glomerular filtration rate. Interestingly, patients with both CTD-related and CTD-unrelated PAH had higher ICOS and ICOS-L serum concentrations than CTD patients (0.0001 for both). When compared to CTD patients, those affected by CTD-PAH showed higher ICOS (440 (240–600) vs. 170 (105–275) pg/mL, p = 0.0001) and ICOS-L serum concentrations (6000 (4300–7000) vs. 2450 (1500–4100) pg/mL; p = 0.0001). In a logistic regression, ICOS and ICOS-L were associated with a diagnosis of PAH, independently from age, gender, and renal function. The corresponding receiver operating characteristic (ROC) curves demonstrated a good diagnostic performance for both ICOS and ICOS-L. Conclusions: ICOS and ICOS-L are increased in patients with PAH, irrespectively from the underlying cause, and represent promising candidate biomarkers for the diagnostic screening for PAH among CTDs patients.

Orthogonal quantification of soluble inducible T-cell costimulator (ICOS) in healthy and diseased human serum

Inducible T-cell costimulator (ICOS), a homodimeric protein expressed on the surface of activated T-cells, is being investigated as a potential therapeutic target to treat various cancers. Recent studies have reported aberrant increases in the soluble form of ICOS (sICOS) in human serum in disease-state patients, primarily using commercial ELISA kits. However, results from our in-house immunoassay did not show these aberrant increases, leading us to speculate that commercial sICOS ELISAs may be prone to interference. We directly tested that hypothesis and found that one widely used commercial kit yields false-positives and is prone to human anti-mouse antibody interference. We then analyzed a panel of healthy, cancer, chronic hepatitis C virus, systemic lupus erythematosus, and diffuse cutaneous systemic sclerosis human serum using our in-house immunoassay and reported the measured sICOS concentrations in these populations. Since even well characterized immunoassay methods are prone to non-specific interference, we also developed a novel sICOS LC-MS/MS method to confirm the results. Using these orthogonal approaches, we show that sICOS is a low abundance soluble protein that cannot be measured above approximately 20 pg/mL in human serum.

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Soluble ICOS is a low-abundance protein that is not detectable above approximately 20 pg/mL in human serum.

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Commercial soluble ICOS kits may be prone to HAMA interference and thus false-positives.

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Off-the-shelf assay kits should be well characterized in order to minimize non-specific interferences.

Single-cell transcriptome analysis identifies skin-specific T-cell responses in systemic sclerosis

OBJECTIVES

Although T cells have been implicated in the pathogenesis of systemic sclerosis (SSc), a comprehensive study of T-cell-mediated immune responses in the affected skin of patients with progressive SSc is lacking. Droplet-based single-cell transcriptome analysis of SSc skin biopsies opens avenues for dissecting patient-specific T-cell heterogeneity, providing a basis for identifying novel gene expression related to functional pathways associated with severity of SSc skin disease.

METHODS

Single-cell RNA sequencing was performed by droplet-based sequencing (10x Genomics), focusing on 3729 CD3⁺ lymphocytes (867 cells from normal and 2862 cells from SSc skin samples) from skin biopsies of 27 patients with active SSc and 10 healthy donors. Confocal immunofluorescence microscopy of progressive SSc skin samples validated transcriptional results and visualised spatial localisations of T-cell subsets.

RESULTS

We identified several subsets of recirculating and tissue-resident T cells in healthy and SSc skin that were associated with distinct signalling pathways. While most clusters shared a common gene expression signature between patients and controls, we identified a unique cluster of recirculating CXCL13⁺ T cells in SSc skin which expressed a T helper follicular-like gene expression signature and that appears to be poised to promote B-cell responses within the inflamed skin of patients.

CONCLUSIONS

Current available therapies to reverse or even slow progression of SSc lead to broad killing of immune cells and consequent toxicities, including death. Identifying the precise immune mechanism(s) driving SSc pathogenesis could lead to innovative therapies that selectively target the aberrant immune response, resulting in better efficacy and less toxicity.

Sex differences in circulating inflammatory mediators as a function of substance use disorder

BACKGROUND

Substance use disorders (SUD) with comorbid depression and anxiety are linked to poor treatment outcome and relapse. Although some depressed individuals exhibit elevated blood-based inflammation (interleukin-6 [IL-6] and C reactive protein [CRP]), few studies have examined whether the presence of SUD exacerbates inflammation.

METHODS

Treatment-seeking individuals with major depressive disorder (MDD), anxiety disorders, and/or SUD (N = 160; 80 % with MDD) recruited into the Tulsa 1000 study provided blood samples, participated in clinical interviews, and completed a questionnaire battery querying symptoms of current psychopathology and emotional processing. Analyses followed a multistep process. First, groups were created on the presence versus absence of 1+ lifetime SUD diagnoses: SUD+ (37 F, 43 M) and SUD- (60 F, 20 M). Second, a principal component analysis (PCA) of questionnaire data resulted in two factors, one indexing negative emotionality/withdrawal motivation and one measuring positive emotionality/approach motivation. Third, SUD groups, extracted PCA factors, and nuisance covariates (age, body mass index [BMI], nicotine use, psychotropic medication [and hormone/contraception use in females]) were entered as simultaneous predictors of blood-based inflammation (IL-6, IL-8, IL-10, tumor necrosis factor-α, and CRP).

RESULTS

Within females, SUD + exhibited higher IL-8 and IL-10 but lower CRP levels than SUD-. In contrast, SUD was not associated with biomarker levels in males. Across sexes, higher BMI was linked to higher IL-6 and CRP levels, and within the five biomarkers, IL-6 and CRP shared the most variance.

CONCLUSION

These findings point to sex-specific inflammatory profiles as a function of SUD that may provide new targets for intervention.

Cytokines and Transgenic Matrix in Autoimmune Diseases: Similarities and Differences

Autoimmune diseases are increasingly recognized as disease entities in which dysregulated cytokines contribute to tissue-specific inflammation. In organ-specific and multiorgan autoimmune diseases, the cytokine profiles show some similarities. Despite these similarities, the cytokines have different roles in the pathogenesis of different diseases. Altered levels or action of cytokines can result from changes in cell signaling. This article describes alterations in the JAK-STAT, TGF-β and NF-κB signaling pathways, which are involved in the pathogenesis of multiple sclerosis and systemic lupus erythematosus. There is a special focus on T cells in preclinical models and in patients afflicted with these chronic inflammatory diseases.

ICOS+ Tregs: A Functional Subset of Tregs in Immune Diseases

Recent studies have reported the pathological effect of ICOS⁺ T cells, but ICOS signals also widely participate in anti-inflammatory responses, particularly ICOS⁺ regulatory T (Treg) cells. The ICOS signaling pathway endows Tregs with increased generation, proliferation, and survival abilities. Furthermore, there is enough evidence to suggest a superior capacity of ICOS⁺ Tregs, which is partly attributable to IL-10 induced by ICOS, yet the associated mechanism needs further investigation. In this review, we discuss the complicated role of ICOS⁺ Tregs in several classical autoimmune diseases, allergic diseases, and cancers and investigate the related therapeutic applications in these diseases. Moreover, we identify ICOS as a potential biomarker for disease treatment and prognostic prediction. In addition, we believe that anti-ICOS/ICOSL monoclonal antibodies exhibit excellent clinical application potential. A thorough understanding of the effect of ICOS⁺ Tregs and the holistic role of ICOS toward the immune system will help to improve the therapeutic schedule of diseases.

Autoantibodies persist in relatives to systemic lupus erythematosus patients during 12 years follow-up

Background

Systemic lupus erythematosus (SLE) is an autoimmune disease with presence of autoantibodies and characteristic multi-organ involvement. Relatives of SLE patients have an increased risk of autoantibody production and autoimmune diseases.

Methods

In 2001, 226 first degree relatives (FDRs) of a population-based cohort of SLE patients were examined for the prevalence of autoantibodies and self-reported health complaints. In 2013, 143 FDRs were re-investigated and deceased’s medical records were examined.

Results

Participants and non-participants were comparable regarding baseline characteristics, while deceased FDRs were older than participants, but with comparable ANA status. ANA status at baseline correlated to ANA status at follow-up. At follow-up, two FDRs reported SLE and 15 FDRs other autoimmune diseases. No observation at baseline alone could predict self-reported health. During follow-up 33 died at median age 76 years. Three deceased FDRs were diagnosed with an autoimmune disease.

Conclusion

The study showed that FDRs of SLE patients have an increased prevalence of ANA compared to healthy controls. The prevalence increased during follow-up, and ANA positive FDRs at baseline were prone to be ANA positive at follow-up. ANA positive FDRs had more self-reported autoimmune diseases, including SLE and rheumatoid arthritis, than reported from other population-based investigations.

Interleukin 10 hampers endothelial cell differentiation and enhances the effects of interferon α on lupus endothelial cell progenitors

OBJECTIVE

SLE is an autoimmune disease characterized by autoantibody generation, organ damage and an increased risk of cardiovascular disease. Generally considered an anti-inflammatory cytokine, IL-10 is increased in SLE and correlates with poor cardiovascular outcomes in the general population. The aim of this study was to explore the putative role of IL-10 in modulating endothelial function in SLE by examining the effects of this cytokine on endothelial progenitor cell/circulating angiogenic cell (EPC/CAC) differentiation.

METHODS

Human and murine control and lupus EPCs/CACs were differentiated into mature endothelial cells (ECs) in the presence or absence of graded concentrations of recombinant IL-10 with or without recombinant IFN-α or a neutralizing antibody to IL-10. IL-10-deficient mice were examined to assess the role of this cytokine in type I IFN-mediated inhibition of EC differentiation and neo-angiogenesis using an in vivo Matrigel plug assay. Serum IL-10 concentrations were measured via ELISA.

RESULTS

IL-10 hampers EC differentiation in a dose-dependent manner. In murine EPC cultures, IL-10 is required to observe the inhibitory effects of type I IFNs on EPC function and neo-angiogenesis. In human SLE EPC/CAC cultures, neutralization of IL-10 significantly improved the differentiation of EPCs, and IL-10 enhanced type I IFN-mediated EPC/CAC dysfunction. The presence of IL-10 in serum inversely correlated with EPC/CAC function in SLE but not in control cells.

CONCLUSION

IL-10 interferes with endothelial differentiation and may enhance the effects of type I IFN on vascular repair in SLE. IL-10 may be a relevant target for improving cardiovascular risk in SLE.

Role of interleukin-10 and interleukin-10 receptor in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a prototypic autoimmune disease characterized by excessive production of a variety of autoantibodies, accumulation of immune complexes, and multiple organ systems involvement. Interleukin-10 (IL-10) has an important role in the growth, survival, differentiation, and function of B cells. Abnormally increased IL-10 synthesis seems contributing to the spontaneous hyperactivity of the B cell compartment, so that it can directly result in autoantibody production by committed plasma cells, circulating immune complexes formation, and eventually in tissue and organ damage, suggesting it might associate with the development of SLE. A better understanding of the regulation of IL-10 and its receptors (IL-10R) can likely provide more valuable clues to the pathogenic mechanisms underlying specific forms of SLE, so as to pave the way toward more effective therapeutics.

IL-10-producing lymphocytes in inflammatory disease

IL-10 is an anti-inflammatory cytokine that plays a significant role in controlling inflammation and modulating adaptive immune responses that cause tissue damage. IL-10-producing lymphocytes contribute to the delicate balance between inflammation and immunoregulation, and are thus regarded as a kind of "regulatory cells." Dysregulation of these cells is linked with susceptibility to numerous inflammatory diseases. In this review, we summarized what is known about the regulatory effects of IL-10 produced by lymphocytes, including T cells, B cells and natural killer cells, in inflammatory diseases. We hope to augment immune responses or prevent immunopathology through making some small changes in the levels of IL-10 produced by lymphocytes, or in the cellular location where it is produced.

Augmented ICOS expression in patients with early diffuse cutaneous systemic sclerosis

OBJECTIVE

Inducible costimulator (ICOS), expressed on activated T cells, and its ligand, ICOS ligand (ICOSL), expressed on antigen-presenting cells, have been considered a single receptor-ligand pair. Here we investigated the expression of ICOS and ICOSL in patients with SSc.

METHODS

ICOS expression on peripheral blood T cells, and ICOSL expression on B cells and macrophages was determined by flow cytometry. Expression of ICOS and ICOSL was assessed by immunohistological staining and real-time PCR of lesional skin.

RESULTS

ICOS expression levels were specifically increased on both peripheral blood memory T cells and Tregs from early dcSSc patients compared with those from healthy controls. Mean ICOSL expression on B cells or macrophages was comparable between SSc patients and healthy controls. ICOS-expressing T cells, ICOSL-expressing macrophages and mRNA levels of ICOS and ICOSL were increased in the lesional skin of patients with early dcSSc. In vitro ICOS costimulation enhanced production of IFN-γ, IL-4 and IL-17A from T cells in SSc patients vs normal controls. Soluble ICOS levels were significantly increased in SSc patients and were negatively associated with the presence of ACAs and positively associated with CRP values. Serum levels of soluble ICOS were more closely associated with clinical features compared with levels of soluble IL-2 receptor.

CONCLUSION

Augmented ICOS signalling may contribute to the pathogenesis of SSc during early progressive disease. Soluble ICOS levels may be used as a serum marker for the activity and severity of SSc.

Polar opposites: Erk direction of CD4 T cell subsets

Effective immune responses depend upon appropriate T cell differentiation in accord with the nature of an infectious agent, and the contingency of differentiation depends minimally on TCR, coreceptor, and cytokine signals. In this reverse genetic study, we show that the MAPK Erk2 is not essential for T cell proliferation in the presence of optimum costimulation. Instead, it has opposite effects on T-bet and Gata3 expression and, hence, on Th1 and Th2 differentiation. Alternatively, in the presence of TGF-β, the Erk pathway suppresses a large program of gene expression, effectively limiting the differentiation of Foxp3(+) regulatory T cells. In the latter case, the mechanisms involved include suppression of Gata3 and Foxp3, induction of Tbx21, phosphorylation of Smad2,3, and possibly suppression of Socs2, a positive inducer of Stat5 signaling. Consequently, loss of Erk2 severely impeded Th1 differentiation while enhancing the development of Foxp3(+)-induced T regulatory cells. Selected profiles of gene expression under multiple conditions of T cell activation illustrate the opposing consequences of Erk pathway signaling.

Pregnancy-associated inflammatory markers are elevated in pregnant women with systemic lupus erythematosus

During normal pregnancy a dampening in T cell-mediated immunity is compensated by an increased pro-inflammatory activity. Likewise, the autoimmune disease systemic lupus erythematosus (SLE) is associated with inflammatory activity and pregnancy complications occur frequently in women with SLE. The aim of this study was to elucidate how SLE influences the chemokine and cytokine balance during and after pregnancy. Blood samples were taken from pregnant women with or without SLE at second and third trimester and 8-12 weeks after pregnancy. Cytokines (interleukin (IL)-1β, IL-2, IL-4, IL-6, IL-10, IL-12p70, IL-17A, TNF, IFN-γ and IFN-α), chemokines (CXCL8/IL-8, CXCL9/MIG, CXCL10/IP-10, CCL2/MCP-1, CCL5/RANTES and CCL17/TARC), soluble IL-6 receptor (sIL-6R) and soluble glycoprotein 130 (gp130) were measured in serum using cytometric bead array (CBA) or enzyme-linked immunosorbent assay (ELISA). Women with SLE had increased serum concentrations of CXCL8/IL-8, CXCL9/MIG, CXCL10/IP-10 and IL-10 compared to controls both during and after pregnancy. Further, when dividing the patients based on disease activity, the women with active disease had the highest levels. Importantly, women with SLE seemed to respond to pregnancy in a similar way as controls, since the changes of cytokines and chemokines over the course of pregnancy were similar but with overall higher levels in the patient group. In conclusion, changes in pro- and anti-inflammatory serum components during pregnancy in women with SLE, occurring on top of already more pro-inflammatory levels, might increase their risk for pregnancy complications and flares. How their children are affected by this heightened inflammatory milieu during pregnancy needs further investigation.

Potential immunologic targets for treating fibrosis in systemic sclerosis: a review focused on leukocytes and cytokines

OBJECTIVES

Systemic sclerosis (SSc) is a connective tissue disease characterized by tissue fibrosis. Although the pathogenesis remains unclear, a variety of cells contribute to the fibrotic process via interactions with each other and production of various cytokines. Recent literature related to the immunologic pathogenesis and future strategies for treating the fibrosis of SSc are discussed and, especially, this literature-based review that includes the authors' perspective, focused on leukocytes and cytokines.

METHODS

A PubMed search for articles published between January 2005 and January 2012 was conducted using the following keywords: systemic sclerosis, leukocyte, cytokine, growth factor, and chemokine. The reference lists of identified articles were searched for further articles.

RESULTS

Targeting profibrogenic cytokines, including transforming growth factor-β, is still a very active area of research in SSc and most cellular studies have focused on the roles of fibroblasts in SSc. However, a growing number of recent studies indicate a role for B cells in the development of SSc and other autoimmune diseases such as systemic lupus erythematosus. Therefore, B-cell-targeted therapies, including currently available monoclonal antibodies against CD19, CD20, CD22, and B-cell-activating factor, belonging to the tumor necrosis factor family represent possible treatment options. Furthermore, the modulation of T-cell costimulatory molecules such as a recombinant fusion protein of cytotoxic T-lymphocyte antigen-4 may be as effective in SSc as it is in treating other autoimmune diseases. Approaches to antagonize interleukin (IL)-1, IL-6, or IL-17A signaling may also be attractive.

CONCLUSIONS

This review describes recent advances in the treatment of fibrosis in SSc patients focused on immunologic strategies, such as leukocyte- or cytokine-targeted therapies.

Lack of nitric oxide synthases increases lipoprotein immune complex deposition in the aorta and elevates plasma sphingolipid levels in lupus

Systemic lupus erythematosus (SLE) patients display impaired endothelial nitric oxide synthase (eNOS) function required for normal vasodilatation. SLE patients express increased compensatory activity of inducible nitric oxide synthase (iNOS) generating excess nitric oxide that may result in inflammation. We examined the effects of genetic deletion of NOS2 and NOS3, encoding iNOS and eNOS respectively, on accelerated vascular disease in MRL/lpr lupus mouse model. NOS2 and NOS3 knockout (KO) MRL/lpr mice had higher plasma levels of triglycerides (23% and 35%, respectively), ceramide (45% and 21%, respectively), and sphingosine 1-phosphate (S1P) (21%) compared to counterpart MRL/lpr controls. Plasma levels of the anti-inflammatory cytokine interleukin 10 (IL-10) in NOS2 and NOS3 KO MRL/lpr mice were lower (53% and 80%, respectively) than counterpart controls. Nodule-like lesions in the adventitia were detected in aortas from both NOS2 and NOS3 KO MRL/lpr mice. Immunohistochemical evaluation of the lesions revealed activated endothelial cells and lipid-laden macrophages (foam cells), elevated sphingosine kinase 1 expression, and oxidized low-density lipoprotein immune complexes (oxLDL-IC). The findings suggest that advanced vascular disease in NOS2 and NOS3 KO MRL/lpr mice maybe mediated by increased plasma triglycerides, ceramide and S1P; decreased plasma IL-10; and accumulation of oxLDL-IC in the vessel wall. The results expose possible new targets to mitigate lupus-associated complications.