BackgroundSystemic sclerosis (SSc) is a disorder characterized by immune system alterations, vasculopathy and fibrosis. SSc-related interstitial lung disease (ILD) represents a common and early complication, being the leading cause of mortality.Monocytes/macrophages seem to have a key role in SSc-related ILD. Interestingly, the classically (M1) and alternatively (M2) activated monocyte/macrophage phenotype categorization is currently under revision.Our aim was to evaluate if circulating monocyte/macrophage phenotype could be used as biomarker for lung involvement in SSc. To this purpose we developed a wide phenotype characterization of circulating monocyte/macrophage subsets in SSc patients and we evaluated possible relations with lung involvement parameter values.MethodsA single centre cross-sectional study was performed in fifty-five consecutive SSc patients, during the year 2017. All clinical and instrumental tests requested for SSc follow up and in particular, lung computed tomography (CT) scan, pulmonary function tests (PFTs), Doppler echocardiography with systolic pulmonary artery pressure (sPAP) measurement, blood pro-hormone of brain natriuretic peptide (pro-BNP) evaluation, were performed in each patient in a maximum one-month period. Flow cytometry characterization of circulating cells belonging to the monocyte/macrophage lineage was performed using specific M1 (CD80, CD86, TLR2 and TLR4) and M2 surface markers (CD204, CD163 and CD206). Non-parametric tests were used for statistical analysis.ResultsA higher percentage of circulating CD204+CD163+CD206+TLR4+CD80+CD86+ and CD14+CD206+CD163+CD204+TLR4+CD80+CD86+ mixed M1/M2 monocyte/macrophage subsets, was identified to characterize patients affected by SSc-related ILD and higher systolic pulmonary artery pressure. Mixed M1/M2 monocyte/macrophage subset showed higher percentages in patients positive for anti-topoisomerase antibody, a known lung involvement predictor.ConclusionsThe present study shows for the first time, through a wide flow cytometry surface marker analysis, that higher circulating mixed M1/M2 monocyte/macrophage cell percentages are associated with ILD, sPAP and anti-topoisomerase antibody positivity in SSc, opening the path for research on their possible role as pathogenic or biomarker elements for SSc lung involvement.Electronic supplementary materialThe online version of this article (10.1186/s12931-018-0891-z) contains supplementary material, which is available to authorized users.

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Celiac disease (CD) is a multifactorial disorder influenced by environmental, genetic and immunological factors. Increasing evidence showed CTLA-4 gene as an important susceptibility locus for autoimmune disorders. A native soluble cytotoxic T-lymphocyte-associated protein-4 (sCTLA-4), lacking of transmembrane sequence, has been described in several autoimmune diseases. We aimed to evaluate the presence of increased sCTLA-4 concentration in the serum of patients with CD and the possible immunoregulatory function. Blood samples were collected from 160 CD patients; sCTLA-4 levels were evaluated by ELISA, western blot and reverse transcription-PCR. The capability of serum sCTLA-4 to modulate T-lymphocyte proliferation in vitro was evaluated by two-way mixed leukocyte reaction assay. We demonstrated high levels of sCTLA-4 in serum of untreated celiac patients. Additionally, we observed that sCTLA-4 concentrations are related to gluten intake and that a correlation between autoantibodies to tissue transglutaminase and sCTLA-4 concentration exists. Moreover, sCTLA-4 levels correlate with the degree of mucosal damage. Conversely, no correlation between sCTLA4 levels and the HLA-related risk was observed. Finally, we show that sCTLA-4 from sera of CD patients displays functional activities. These results strongly suggest a regulation of sCTLA-4 synthesis depending on the presence or absence of dietary gluten and imply a possible immunomodulatory effect on cytotoxic T lymphocyte functions. In gluten-exposed patients, serum sCTLA-4 levels might provide insight about mucosal injury.

To investigate the effects of 17beta-estradiol (E2) on extracellular matrix (ECM) protein synthesis (collagen type I, fibronectin, and laminin) using cultures of normal and scleroderma (SSc) skin fibroblasts. Primary fibroblasts cultures, obtained from skin biopsies of six female voluntary subjects and three female SSc patients, were treated for 24 h with E2 (10(-10)M) alone or in combination with tamoxifene (TAM, 10(-7)M) as an estrogen receptor (ER) antagonist. ECM protein synthesis was analyzed by immunocytochemistry and Western blotting. E2 induced a significant increase of fibronectin, collagen type I, and laminin synthesis both in normal (P < 0.01, P < 0.05, P < 0.01, respectively) and SSc fibroblasts (P < 0.001, P < 0.05, P < 0.001, respectively) when compared to untreated fibroblasts. TAM induced a significant decrease of ECM protein synthesis when compared to E2-treated TAM-untreated fibroblasts. This study seems to support important modulatory effects of E2 in the fibrotic progression of the SSc process via ER interactions.

Background Aromatases increase estrogen synthesis in inflammatory tissues whereas vitamin D (calcitriol, 1,25-dihydroxyvitamin D3, 1,25(OH)2D3) seems to decrease the aromatase expression at least in human cancer cells (BCa cells) (1). Interestingly, the aromatase activity is increased together with the estrogen synthesis in the synovial tissue of rheumatoid arthritis (RA) patients, especially at the level of macrophages (2-4). Objectives To evaluate in cultures of human activated macrophages the influence exerted by calcitriol on aromatase expression, as a new target for 1,25(OH)2D3cell modulation of proinflammatory cytokine production (5). Methods Cultures of human monocytic THP-1 were activated to macrophages and treated for 24 hours with 1,25(OH)2D3 (10-8M), alone or in combination with 17b-estradiol (E2, 10-8M), in order to evaluate the effects on the intracrine estrogen metabolism (aromatase-driven) and cytokine synthesis. Untreated human macrophages were used as controls (basal condition). P450-aromatase synthesis was evaluated by immunocytochemistry (ICC) and western blot analysis (WB). The expression of P450-aromatase gene (CYP19A1) was investigated by real-time PCR (RT-PCR). Macrophage proinflammatory cytokines IL1-β, IL-6 and TNF-α were evaluated by ELISA and WB. Results Interestingly, 1,25(OH)2D3 downregulated P450-aromatase synthesis, CYP19A1-gene expression, and proinflammatory cytokine production (IL1-β, IL-6 and TNF-α) in basal conditions when compared to 1,25(OH)2D3-untreated macrophages. However and interestingly, the treatment with 1,25(OH)2D3significantly reduced the increase in P450-aromatase (p<0.001), CYP19A1 gene expression (p<0.001) as well as IL-1bβ, IL-6, TNF-α production (p<0.001) induced by estrogen treatment vs. estrogen-treated (but 1,25(OH)2D3-untreated) macrophages. Conclusions Our data suggest that 1,25(OH)2D3 may downregulate the proinflammatory cytokine production in human activated macrophages by significantly decreasing the aromatase activity, especially in presence of an enhancing estrogenic milieu. Interestingly, this latter hormonal metabolic condition is observed in the synovial tissue and fluid of RA patients of both sexes (2,3). References Krishnan AV et al. Endocrinology 2010;151:32-42. Cutolo M et al. Autoimmun Rev. 2011;2 [Epub ahead of print]. Cutolo M. Rheumatology (Oxford) 2009;48:210-12. Le Bail J et al. Steroids. 2001;66:749-57. Zwerina K et al. Ann Rheum Dis. 2011;70:1122-9. Disclosure of Interest None Declared

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IntroductionCo-stimulatory signal B7(CD80/CD86):CD28 is needed in order to activate T cells in immune response. Cytotoxic T lymphocyte-associated antigen-4-immunoglobulin (CTLA4-Ig) binding to the B7 molecules on antigen-presenting cells downregulates this activation and represents a recent biological treatment in rheumatoid arthritis (RA). Objectives of the study were to investigate the presence of the B7.2 (CD86) molecule and its masking by CTLA4-Ig on cultures of both RA synovial macrophages (RA SM), and of macrophages differentiated from THP-1 cells (M). In addition, the anti-inflammatory effects of CTLA4-Ig on co-cultures of RA SM and M with activated T cells were tested.MethodsAll macrophages were co-cultured for 24 hours with activated T cells, without or with CTLA4-Ig (10, 100, 500 μg/ml for 1 hour, 3 hours and overnight, respectively). Immunofluorescence (IF) staining for B7.2, and an analysis of inflammatory cytokine expression (interleukin (IL) -6, tumor necrosis factor (TNF) α, IL-1β, transforming growth factor (TGF) β) by immunocytochemistry (ICC), western blot (WB) and reverse transcriptase-polymerase chain reaction (RT-PCR) were performed.ResultsMacrophages showed intense B7.2 expression. CTLA4-Ig/B7.2 masking was evident for all macrophages, even after only 1 hour of cell culture (range from 10 to 100 μg/ml). ICC of co-cultures showed a dose-dependent decrease in inflammatory cytokines (P < 0.001 for IL-6, TNFα, IL-1β and TGFβ). Data were confirmed by WB and RT-PCR analysis.ConclusionsOptimal concentrations of CTLA4-Ig for the CTLA4-Ig/B7.2 masking on activated macrophages were identified and were found to induce significant downregulation in the cell production of IL-6, TNFα, IL1-β and TGFβ. In conclusion, macrophages would appear to be a sensitive target for CTLA4-Ig treatment in RA.

Highest ET-1 plasma levels were detected in the more advanced stage of the SSc microangiopathy, namely the late NVC pattern, characterized by capillary loss and increased tissue fibrosis; this might support the involvement of ET-1 in the progression of the microvascular/fibrotic SSc damage.