scholarly journals RNA-Containing Immune Complexes Formed by Anti-Melanoma Differentiation Associated Gene 5 Autoantibody Are Potent Inducers of IFN-α

2021 ◽  
Vol 12 ◽  
Author(s):  
Kaiwen Wang ◽  
Jiangfeng Zhao ◽  
Wanlong Wu ◽  
Wenwen Xu ◽  
Shuhui Sun ◽  
...  

ObjectiveAnti-melanoma differentiation-associated gene 5 (MDA5) autoantibody is a distinctive serology hallmark of dermatomyositis (DM). As an autoantigen, MDA5 is a cytoplasmic RNA recognition receptor. The aim of this study was to address the question of whether the RNA-containing immune complex (IC) formed by MDA5 and anti-MDA5 could activate type I interferon (IFN) response.MethodPatients with anti-MDA5+ DM (n = 217), anti-MDA5− DM (n = 68), anti-synthase syndrome (ASyS, n = 57), systemic lupus erythematosus (SLE, n = 245), rheumatoid arthritis (RA, n = 89), and systemic sclerosis (SSc, n = 30) and healthy donors (HD, n = 94) were enrolled in our studies. Anti-MDA5 antibody was detected by line blotting, enzyme-linked immunosorbent assay (ELISA), immunoprecipitation, and Western blotting. Cytokine profiling was determined by multiplex flow cytometry, and IFN-α was further measured by ELISA. Type I IFN-inducible genes were detected by quantitative PCR (qPCR). RNA–IC binding was analyzed by RNA immunoprecipitation. Plasmacytoid dendritic cells (pDCs) derived from healthy donors were cultivated and stimulated with MDA5 ICs with or without RNase and Toll-like receptor 7 (TLR-7) agonist. The interaction between MDA5 ICs and TLR7 was evaluated by immunoprecipitation and confocal microscopy.ResultsAccording to our in-house ELISA, the presence of anti-MDA5 antibody in 76.1% of DM patients, along with 14.3% of SLE patients who had a lower titer yet positive anti-MDA5 antibody, was related to the high level of peripheral IFN-α. ICs formed by MDA5 and anti-MDA5 were potent inducers of IFN-α via TLR-7 in an RNA-dependent manner in vitro.ConclusionOur data provided evidence of the mechanistic relevance between the anti-MDA5 antibody and type I IFN pathway.

2019 ◽  
Vol 39 (12) ◽  
Author(s):  
Fangyi Zhang ◽  
Xuefeng Lin ◽  
Xiaodong Yang ◽  
Guangjian Lu ◽  
Qunmei Zhang ◽  
...  

Abstract Increasing evidence has indicated that microRNAs (miRNAs) have essential roles in innate immune responses to various viral infections; however, the role of miRNAs in H1N1 influenza A virus (IAV) infection is still unclear. The present study aimed to elucidate the role and mechanism of miRNAs in IAV replication in vitro. Using a microarray assay, we analyzed the expression profiles of miRNAs in peripheral blood from IAV patients. It was found that miR-132-3p was significantly up-regulated in peripheral blood samples from IAV patients. It was also observed that IAV infection up-regulated the expression of miR-132-3p in a dose- and time-dependent manner. Subsequently, we investigated miR-132-3p function and found that up-regulation of miR-132-3p promoted IAV replication, whereas knockdown of miR-132-3p repressed replication. Meanwhile, overexpression of miR-132-3p could inhibit IAV triggered INF-α and INF-β production and IFN-stimulated gene (ISG) expression, including myxovirus protein A (MxA), 2′,5′-oligoadenylate synthetases (OAS), and double-stranded RNA-dependent protein kinase (PKR), while inhibition of miR-132-3p enhanced IAV triggered these effects. Of note, interferon regulatory factor 1 (IRF1), a well-known regulator of the type I IFN response, was identified as a direct target of miR-132-3p during HIN1 IAV infection. Furthermore, knockdown of IRF1 by si-IRF1 reversed the promoting effects of miR-132-3p inhibition on type I IFN response. Taken together, up-regulation of miR-132-3p promotes IAV replication by suppressing type I IFN response through its target gene IRF1, suggesting that miR-132-3p could represent a novel potential therapeutic target of IAV treatment.


2021 ◽  
Vol 12 ◽  
Author(s):  
Qing Yan ◽  
Weiwei Chen ◽  
Hua Song ◽  
Xianming Long ◽  
Zhuoya Zhang ◽  
...  

Autoreactive T cells play a crucial role in the pathogenesis of systemic lupus erythematosus (SLE). TGF-β type I receptor (TGFβRI) is pivotal in determining T cell activation. Here, we showed that TGFβRI expression in naïve CD4+ T cells was decreased in SLE patients, especially in those with high disease activity. Moreover, IL-6 was found to downregulate TGFβRI expression through JAK/STAT3 pathway in SLE patients. In vitro, the JAK inhibitor tofacitinib inhibited SLE T cell activating by upregulating TGFβRI expression in a dose-dependent manner. In MRL/lpr mice, tofacitinib treatment ameliorated the clinical indicators and lupus nephritis, as evidenced by reduced plasma anti-dsDNA antibody levels, decreased proteinuria, and lower renal histopathological score. Consistently, tofacitinib enhanced TGFβRI expression and inhibited T cell activation in vivo. TGFβRI inhibitor SB431542 reversed the effects of tofacitinib on T cell activation. Thus, our results have indicated that tofacitinib can suppress T cell activation by upregulating TGFβRI expression, which provides a possible molecular mechanism underlying clinical efficacy of tofacitinib in treating SLE patients.


2021 ◽  
Vol 22 (21) ◽  
pp. 11903
Author(s):  
Jarmila Knitlova ◽  
Martina Doubkova ◽  
Adam Eckhardt ◽  
Martin Ostadal ◽  
Jana Musilkova ◽  
...  

Congenital clubfoot is a complex musculoskeletal deformity, in which a stiff, contracted tissue forms in the medial part of the foot. Fibrotic changes are associated with increased collagen deposition and lysyl oxidase (LOX)‑mediated crosslinking, which impair collagen degradation and increase the tissue stiffness. First, we studied collagen deposition, as well as the expression of collagen and the amount of pyridinoline and deoxypyridinoline crosslinks in the tissue of relapsed clubfoot by immunohistochemistry, real-time PCR, and enzyme-linked immunosorbent assay (ELISA). We then isolated fibroblast‑like cells from the contracted tissue to study the potential inhibition of these processes in vitro. We assessed the effects of a LOX inhibitor, β‑aminopropionitrile (BAPN), on the cells by a hydroxyproline assay, ELISA, and Second Harmonic Generation imaging. We also evaluated the cell-mediated contraction of extracellular matrix in 3D cell‑populated collagen gels. For the first time, we have confirmed significantly increased crosslinking and excessive collagen type I deposition in the clubfoot-contracted tissue. We successfully reduced these processes in vitro in a dose-dependent manner with 10–40 µg/mL of BAPN, and we observed an increasing trend in the inhibition of the cell‑mediated contraction of collagen gels. The in vitro inhibitory effects indicate that BAPN has good potential for the treatment of relapsed and resistant clubfeet.


2008 ◽  
Vol 206 (1) ◽  
pp. 249-258 ◽  
Author(s):  
Cristina Albanesi ◽  
Claudia Scarponi ◽  
Sabatino Pallotta ◽  
Roberta Daniele ◽  
Daniela Bosisio ◽  
...  

Psoriasis is a type I interferon-driven T cell–mediated disease characterized by the recruitment of plasmacytoid dendritic cells (pDC) into the skin. The molecules involved in pDC accumulation in psoriasis lesions are unknown. Chemerin is the only inflammatory chemotactic factor that is directly active on human blood pDC in vitro. The aim of this study was to evaluate the role of the chemerin/ChemR23 axis in the recruitment of pDC in psoriasis skin. Prepsoriatic skin adjacent to active lesions and early lesions were characterized by a strong expression of chemerin in the dermis and by the presence of CD15+ neutrophils and CD123+/BDCA-2+/ChemR23+ pDC. Conversely, skin from chronic plaques showed low chemerin expression, segregation of neutrophils to epidermal microabscesses, and few pDC in the dermis. Chemerin expression was localized mainly in fibroblasts, mast cells, and endothelial cells. Fibroblasts cultured from skin of psoriatic lesions expressed higher levels of chemerin messenger RNA and protein than fibroblasts from uninvolved psoriatic skin or healthy donors and promoted pDC migration in vitro in a chemerin-dependent manner. Therefore, chemerin expression specifically marks the early phases of evolving skin psoriatic lesions and is temporally strictly associated with pDC. These results support a role for the chemerin/ChemR23 axis in the early phases of psoriasis development.


2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
L. Kui ◽  
G. C. Chan ◽  
P. P. W. Lee

Proinflammatory cytokines such as TNF-α and type I interferons (IFN) are pathogenic signatures of systemic lupus erythematosus, and plasmacytoid dendritic cells (pDCs) play a major role by predominantly producing IFN-α. Given the rise of importance in identifying tumor necrosis stimulated gene 6 (TSG-6) as a key anti-inflammatory regulator, we investigate its function and its ability to counteract proinflammatory cytokine secretion by pDCs in vitro. CpG-A and R837 induced significant endogenous TSG-6 expression in the pDC cell-line GEN2.2. Following recombinant human TSG-6 treatment and CpG-A or R837 stimulation, significant reduction in IFN-α and TNF-α was observed in healthy donors’ pDCs, and the same phenomenon was confirmed in GEN2.2. By CD44 blocking assay, we deduced that the suppressive effect of TSG-6 is mediated by CD44, by reducing IRF-7 phosphorylation. Our findings suggest that TSG-6 and its downstream signalling pathway could potentially be targeted to modulate proinflammatory cytokine expression in pDCs.


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1373.3-1373
Author(s):  
M. J. Wahadat ◽  
M. Lourens ◽  
E. Huijser ◽  
C. G. Van Helden-Meeuwsen ◽  
S. Kamphuis ◽  
...  

Background:Systemic Lupus Erythematosus (SLE) is prototypic Interferon (IFN) driven autoimmune disease characterized by an increased expression of type-I IFN stimulated genes, known as the IFN signature. The inhibitory effects of various drugs like Hydroxychloroquine and more recently Aspirin on IFN inducing pathways (1, 2) led to the idea that some standard of care drugs might decrease the IFN score in patients. Data on the in vitro effect of immunosuppressive medication on IFN activation are limited. Testing immunosuppressive agents for their effect on IFN activation in vitro will give insight into the mechanisms of IFN activation in vivo and the effect of immunosuppressive medication on this activation.Objectives:To study the effect of immunosuppressive medication on the type-I IFN signature in anin vitromodelMethods:Freshly isolated human PBMCs were stimulated for 24 hours with or without CpG-A or Imiquimod (IQ) or transfected with the cGAS agonist G3-YSD to induce IFN upregulation through the TLR7/9- and DNA Sensing Receptor-pathway respectively. To assess the direct role of the medication on the downstream pathway of the IFNAR PBMCs were stimulated with IFN-a2b. Aspirin, diclofenac, HCQ, Mycophenolate Mofetil (MMF) and prednisone were added separately to these cultures followed by analysis of MxA by qPCR as a readout for IFN type I activation. Cell viability in all culture conditions was above 85%.Results:The type I IFN activation induced by CpG-A, IQ, G3-YSD and IFN-a2b was significantly reduced after addition of Aspirin. Addition of diclofenac showed a trend towards reduced levels in all conditions. HCQ was able to significantly reduce the TLR7/9 induced IFN activation by CpG-A and IQ while MMF and prednisone did not show an effect in any of the culture conditions.Conclusion:The IFN activation induced by the stimulation of various IFN inducing pathways was significantly reduced by Aspirin and HCQ in an in vitro model. Combining both clinical andin vitrodata from our longitudinal cohort of childhood-onset SLE patients will elucidate the effect of different immunosuppressive drugs on the type-I IFN signature in these patients.References:[1]Kuznik A, Bencina M, Svajger U, Jeras M, Rozman B, Jerala R. Mechanism of endosomal TLR inhibition by antimalarial drugs and imidazoquinolines. J Immunol. 2011;186(8):4794-804.[2]Dai J, Huang YJ, He X, Zhao M, Wang X, Liu ZS, et al. Acetylation Blocks cGAS Activity and Inhibits Self-DNA-Induced Autoimmunity. Cell. 2019;176(6):1447-60 e14.Disclosure of Interests:None declared


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 4-5
Author(s):  
A. Aue ◽  
F. Szelinski ◽  
S. Weißenberg ◽  
A. Wiedemann ◽  
T. Rose ◽  
...  

Background:Systemic lupus erythematosus (SLE) is characterized by two pathogenic key signatures, type I interferon (IFN) (1.) and B-cell abnormalities (2.). How these signatures are interrelated is not known. Type I-II IFN trigger activation of Janus kinase (JAK) – signal transducer and activator of transcription (STAT).Objectives:JAK-STAT inhibition is an attractive therapeutic possibility for SLE (3.). We assess STAT1 and STAT3 expression and phosphorylation at baseline and after IFN type I and II stimulation in B-cell subpopulations of SLE patients compared to other autoimmune diseases and healthy controls (HD) and related it to disease activity.Methods:Expression of STAT1, pSTAT1, STAT3 and pSTAT3 in B and T-cells of 21 HD, 10 rheumatoid arthritis (RA), 7 primary Sjögren’s (pSS) and 22 SLE patients was analyzed by flow cytometry. STAT1 and STAT3 expression and phosphorylation in PBMCs of SLE patients and HD after IFNα and IFNγ incubation were further investigated.Results:SLE patients showed substantially higher STAT1 but not pSTAT1 in B and T-cell subsets. Increased STAT1 expression in B cell subsets correlated significantly with SLEDAI and Siglec-1 on monocytes, a type I IFN marker (4.). STAT1 activation in plasmablasts was IFNα dependent while monocytes exhibited dependence on IFNγ.Figure 1.Significantly increased expression of STAT1 by SLE B cells(A) Representative histograms of baseline expression of STAT1, pSTAT1, STAT3 and pSTAT3 in CD19+ B cells of SLE patients (orange), HD (black) and isotype controls (grey). (B) Baseline expression of STAT1 and pSTAT1 or (C) STAT3 and pSTAT3 in CD20+CD27-, CD20+CD27+ and CD20lowCD27high B-lineage cells from SLE (orange) patients compared to those from HD (black). Mann Whitney test; ****p≤0.0001.Figure 2.Correlation of STAT1 expression by SLE B cells correlates with type I IFN signature (Siglec-1, CD169) and clinical activity (SLEDAI).Correlation of STAT1 expression in CD20+CD27- näive (p<0.0001, r=0.8766), CD20+CD27+ memory (p<0.0001, r=0.8556) and CD20lowCD27high (p<0.0001, r=0.9396) B cells from SLE patients with (A) Siglec-1 (CD169) expression on CD14+ cells as parameter of type I IFN signature and (B) lupus disease activity (SLEDAI score). Spearman rank coefficient (r) was calculated to identify correlations between these parameters. *p≤0.05, **p≤0.01. (C) STAT1 expression in B cell subsets of a previously undiagnosed, active SLE patient who was subsequently treated with two dosages of prednisolone and reanalyzed.Conclusion:Enhanced expression of STAT1 by B-cells candidates as key node of two immunopathogenic signatures (type I IFN and B-cells) related to important immunopathogenic pathways and lupus activity. We show that STAT1 is activated upon IFNα exposure in SLE plasmablasts. Thus, Jak inhibitors, targeting JAK-STAT pathways, hold promise to block STAT1 expression and control plasmablast induction in SLE.References:[1]Baechler EC, Batliwalla FM, Karypis G, Gaffney PM, Ortmann WA, Espe KJ, et al. Interferon-inducible gene expression signature in peripheral blood cells of patients with severe lupus. Proc Natl Acad Sci U S A. 2003;100(5):2610-5.[2]Lino AC, Dorner T, Bar-Or A, Fillatreau S. Cytokine-producing B cells: a translational view on their roles in human and mouse autoimmune diseases. Immunol Rev. 2016;269(1):130-44.[3]Dorner T, Lipsky PE. Beyond pan-B-cell-directed therapy - new avenues and insights into the pathogenesis of SLE. Nat Rev Rheumatol. 2016;12(11):645-57.[4]Biesen R, Demir C, Barkhudarova F, Grun JR, Steinbrich-Zollner M, Backhaus M, et al. Sialic acid-binding Ig-like lectin 1 expression in inflammatory and resident monocytes is a potential biomarker for monitoring disease activity and success of therapy in systemic lupus erythematosus. Arthritis Rheum. 2008;58(4):1136-45.Disclosure of Interests:Arman Aue: None declared, Franziska Szelinski: None declared, Sarah Weißenberg: None declared, Annika Wiedemann: None declared, Thomas Rose: None declared, Andreia Lino: None declared, Thomas Dörner Grant/research support from: Janssen, Novartis, Roche, UCB, Consultant of: Abbvie, Celgene, Eli Lilly, Roche, Janssen, EMD, Speakers bureau: Eli Lilly, Roche, Samsung, Janssen


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Norzawani Buang ◽  
Lunnathaya Tapeng ◽  
Victor Gray ◽  
Alessandro Sardini ◽  
Chad Whilding ◽  
...  

AbstractThe majority of patients with systemic lupus erythematosus (SLE) have high expression of type I IFN-stimulated genes. Mitochondrial abnormalities have also been reported, but the contribution of type I IFN exposure to these changes is unknown. Here, we show downregulation of mitochondria-derived genes and mitochondria-associated metabolic pathways in IFN-High patients from transcriptomic analysis of CD4+ and CD8+ T cells. CD8+ T cells from these patients have enlarged mitochondria and lower spare respiratory capacity associated with increased cell death upon rechallenge with TCR stimulation. These mitochondrial abnormalities can be phenocopied by exposing CD8+ T cells from healthy volunteers to type I IFN and TCR stimulation. Mechanistically these ‘SLE-like’ conditions increase CD8+ T cell NAD+ consumption resulting in impaired mitochondrial respiration and reduced cell viability, both of which can be rectified by NAD+ supplementation. Our data suggest that type I IFN exposure contributes to SLE pathogenesis by promoting CD8+ T cell death via metabolic rewiring.


2021 ◽  
Vol 22 (1) ◽  
pp. 394
Author(s):  
Simone Krueger ◽  
Alexander Riess ◽  
Anika Jonitz-Heincke ◽  
Alina Weizel ◽  
Anika Seyfarth ◽  
...  

In cell-based therapies for cartilage lesions, the main problem is still the formation of fibrous cartilage, caused by underlying de-differentiation processes ex vivo. Biophysical stimulation is a promising approach to optimize cell-based procedures and to adapt them more closely to physiological conditions. The occurrence of mechano-electrical transduction phenomena within cartilage tissue is physiological and based on streaming and diffusion potentials. The application of exogenous electric fields can be used to mimic endogenous fields and, thus, support the differentiation of chondrocytes in vitro. For this purpose, we have developed a new device for electrical stimulation of chondrocytes, which operates on the basis of capacitive coupling of alternating electric fields. The reusable and sterilizable stimulation device allows the simultaneous use of 12 cavities with independently applicable fields using only one main supply. The first parameter settings for the stimulation of human non-degenerative chondrocytes, seeded on collagen type I elastin-based scaffolds, were derived from numerical electric field simulations. Our first results suggest that applied alternating electric fields induce chondrogenic re-differentiation at the gene and especially at the protein level of human de-differentiated chondrocytes in a frequency-dependent manner. In future studies, further parameter optimizations will be performed to improve the differentiation capacity of human cartilage cells.


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