scholarly journals The transcription factor NFAT5 limits infection-induced type I interferon responses

2019 ◽  
Vol 217 (3) ◽  
Author(s):  
Hector Huerga Encabo ◽  
Laia Traveset ◽  
Jordi Argilaguet ◽  
Ana Angulo ◽  
Estanislao Nistal-Villán ◽  
...  
Keyword(s):  
Inflammatory Responses ◽  
Type I Interferon ◽  
Poly I:C ◽  
Type I ◽  
Hematopoietic Stem ◽  
Inflammatory Reactions ◽  
Conserved Sequence ◽  
Evolutionarily Conserved ◽  
And Function ◽  
Interferon Responses

Type I interferon (IFN-I) provides effective antiviral immunity but can exacerbate harmful inflammatory reactions and cause hematopoietic stem cell (HSC) exhaustion; therefore, IFN-I expression must be tightly controlled. While signaling mechanisms that limit IFN-I induction and function have been extensively studied, less is known about transcriptional repressors acting directly on IFN-I regulatory regions. We show that NFAT5, an activator of macrophage pro-inflammatory responses, represses Toll-like receptor 3 and virus-induced expression of IFN-I in macrophages and dendritic cells. Mice lacking NFAT5 exhibit increased IFN-I production and better control of viral burden upon LCMV infection but show exacerbated HSC activation under systemic poly(I:C)-induced inflammation. We identify IFNβ as a primary target repressed by NFAT5, which opposes the master IFN-I inducer IRF3 by binding to an evolutionarily conserved sequence in the IFNB1 enhanceosome that overlaps a key IRF site. These findings illustrate how IFN-I responses are balanced by simultaneously opposing transcription factors.

scholarly journals Siglec-H-Deficient Mice Show Enhanced Type I IFN Responses, but Do Not Develop Autoimmunity After Influenza or LCMV Infections

2021 ◽  
Vol 12 ◽  
Author(s):  
Nadine Szumilas ◽  
Odilia B. J. Corneth ◽  
Christian H. K. Lehmann ◽  
Heike Schmitt ◽  
Svenia Cunz ◽  
...  
Keyword(s):  
Autoimmune Disease ◽  
Inflammatory Responses ◽  
Type I Interferon ◽  
Acute Infection ◽  
Murine Cytomegalovirus ◽  
Type I ◽  
Virus Infections ◽  
Mcmv Infection ◽  
Interferon Responses ◽  
Deficient Mice

Siglec-H is a DAP12-associated receptor on plasmacytoid dendritic cells (pDCs) and microglia. Siglec-H inhibits TLR9-induced IFN-α production by pDCs. Previously, it was found that Siglec-H-deficient mice develop a lupus-like severe autoimmune disease after persistent murine cytomegalovirus (mCMV) infection. This was due to enhanced type I interferon responses, including IFN-α. Here we examined, whether other virus infections can also induce autoimmunity in Siglec-H-deficient mice. To this end we infected Siglec-H-deficient mice with influenza virus or with Lymphocytic Choriomeningitis virus (LCMV) clone 13. With both types of viruses we did not observe induction of autoimmune disease in Siglec-H-deficient mice. This can be explained by the fact that both types of viruses are ssRNA viruses that engage TLR7, rather than TLR9. Also, Influenza causes an acute infection that is rapidly cleared and the chronicity of LCMV clone 13 may not be sufficient and may rather suppress pDC functions. Siglec-H inhibited exclusively TLR-9 driven type I interferon responses, but did not affect type II or type III interferon production by pDCs. Siglec-H-deficient pDCs showed impaired Hck expression, which is a Src-family kinase expressed in myeloid cells, and downmodulation of the chemokine receptor CCR9, that has important functions for pDCs. Accordingly, Siglec-H-deficient pDCs showed impaired migration towards the CCR9 ligand CCL25. Furthermore, autoimmune-related genes such as Klk1 and DNase1l3 are downregulated in Siglec-H-deficient pDCs as well. From these findings we conclude that Siglec-H controls TLR-9-dependent, but not TLR-7 dependent inflammatory responses after virus infections and regulates chemokine responsiveness of pDCs.

scholarly journals Vaccinia Virus-Mediated Inhibition of Type I Interferon Responses Is a Multifactorial Process Involving the Soluble Type I Interferon Receptor B18 and Intracellular Components

2008 ◽  
Vol 83 (4) ◽  
pp. 1563-1571 ◽  
Author(s):  
Zoe Waibler ◽  
Martina Anzaghe ◽  
Theresa Frenz ◽  
Astrid Schwantes ◽  
Christopher Pöhlmann ◽  
...  
Keyword(s):  
Vaccinia Virus ◽  
Type I Interferon ◽  
Poly I:C ◽  
Host Responses ◽  
Type I ◽  
Immune Modulators ◽  
Modified Vaccinia Virus Ankara ◽  
Multistep Process ◽  
Interferon Responses

ABSTRACT Poxviruses such as virulent vaccinia virus (VACV) strain Western Reserve encode a broad range of immune modulators that interfere with host responses to infection. Upon more than 570 in vitro passages in chicken embryo fibroblasts (CEF), chorioallantois VACV Ankara (CVA) accumulated mutations that resulted in highly attenuated modified vaccinia virus Ankara (MVA). MVA infection of mice and of dendritic cells (DC) induced significant type I interferon (IFN) responses, whereas infection with VACV alone or in combination with MVA did not. These results implied that VACV expressed an IFN inhibitor(s) that was functionally deleted in MVA. To further characterize the IFN inhibitor(s), infection experiments were carried out with CVA strains isolated after 152 (CVA152) and 386 CEF passages (CVA386). Interestingly, neither CVA152 nor CVA386 induced IFN-α, whereas the latter variant did induce IFN-β. This pattern suggested a consecutive loss of inhibitors during MVA attenuation. Similar to supernatants of VACV- and CVA152-infected DC cultures, recombinantly expressed soluble IFN decoy receptor B18, which is encoded in the VACV genome, inhibited MVA-induced IFN-α but not IFN-β. In the same direction, a B18R-deficient VACV variant triggered only IFN-α, confirming B18 as the soluble IFN-α inhibitor. Interestingly, VACV infection inhibited IFN responses induced by a multitude of different stimuli, including oligodeoxynucleotides containing CpG motifs, poly(I:C), and vesicular stomatitis virus. Collectively, the data presented show that VACV-mediated IFN inhibition is a multistep process involving secreted factors such as B18 plus intracellular components that cooperate to efficiently shut off systemic IFN-α and IFN-β responses.

scholarly journals Role of MDA5 in regulating CXCL10 expression induced by TLR3 signaling in human rheumatoid fibroblast-like synoviocytes

2021 ◽  
Author(s):  
Tatsuro Saruga ◽  
Tadaatsu Imaizumi ◽  
Shogo Kawaguchi ◽  
Kazuhiko Seya ◽  
Tomoh Matsumiya ◽  
...  
Keyword(s):  
Inflammatory Responses ◽  
Neutralizing Antibody ◽  
Poly I:C ◽  
Enzyme Linked Immunosorbent Assay ◽  
Dependent Manner ◽  
Inflammatory Reactions ◽  
Polyinosinic:Polycytidylic Acid ◽  
Tlr3 Signaling ◽  
Fibroblast Like Synoviocytes

AbstractC-X-C motif chemokine 10 (CXCL10) is an inflammatory chemokine and a key molecule in the pathogenesis of rheumatoid arthritis (RA). Melanoma differentiation-associated gene 5 (MDA5) is an RNA helicase that plays a role in innate immune and inflammatory reactions. The details of the regulatory mechanisms of CXCL10 production and the precise role of MDA5 in RA synovitis have not been fully elucidated. The aim of this study was to examine the role of MDA5 in regulating CXCL10 expression in cultured human rheumatoid fibroblast-like synoviocytes (RFLS). RFLS was stimulated with Toll-like receptor 3 (TLR3) ligand polyinosinic:polycytidylic acid (poly I:C), a synthetic double-stranded RNA mimetic. Expression of interferon beta (IFN-β), MDA5, and CXCL10 was measured by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR), western blotting, and enzyme-linked immunosorbent assay. A neutralizing antibody of IFN-β and siRNA-mediated MDA5 knockdown were used to determine the role of these molecules in regulating CXCL10 expression downstream of TLR3 signaling in RFLS. Poly I:C induced IFN-β, MDA5, and CXCL10 expression in a concentration- and time-dependent manner. IFN-β neutralizing antibody suppressed the expression of MDA5 and CXCL10, and knockdown of MDA5 decreased a part of CXCL10 expression (p < 0.001). The TLR3/IFN-β/CXCL10 axis may play a crucial role in the inflammatory responses in RA synovium, and MDA5 may be partially involved in this axis.

Anemoside B4 inhibits enterovirus 71 propagation in mice through upregulating 14-3-3 expression and type I interferon responses

2021 ◽  
Author(s):  
Nai-xin Kang ◽  
Yue Zou ◽  
Qing-hua Liang ◽  
Yan-er Wang ◽  
Yan-li Liu ◽  
...  
Keyword(s):  
Type I Interferon ◽  
Enterovirus 71 ◽  
Type I ◽  
Interferon Responses

scholarly journals Investigation of type I interferon responses in ANCA-associated vasculitis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Isabella Batten ◽  
Mark W. Robinson ◽  
Arthur White ◽  
Cathal Walsh ◽  
Barbara Fazekas ◽  
...  
Keyword(s):  
Protein Expression ◽  
Type I Interferon ◽  
Contributory Factor ◽  
Type I ◽  
Healthy Controls ◽  
Type I Ifn ◽  
Serum Samples ◽  
Anca Associated Vasculitis ◽  
Clinical Measurements ◽  
Interferon Responses

AbstractType I interferon (IFN) dysregulation is a major contributory factor in the development of several autoimmune diseases, termed type I interferonopathies, and is thought to be the pathogenic link with chronic inflammation in these conditions. Anti-neutrophil cytoplasmic antibody (ANCA)-Associated Vasculitis (AAV) is an autoimmune disease characterised by necrotising inflammation of small blood vessels. The underlying biology of AAV is not well understood, however several studies have noted abnormalities in type I IFN responses. We hypothesised that type I IFN responses are systemically dysregulated in AAV, consistent with features of a type I interferonopathy. To investigate this, we measured the expression of seven interferon regulated genes (IRGs) (ISG15, SIGLEC1, STAT1, RSAD2, IFI27, IFI44L and IFIT1) in peripheral blood samples, as well as three type I IFN regulated proteins (CXCL10, MCP-1 and CCL19) in serum samples from AAV patients, healthy controls and disease controls. We found no difference in type I IFN regulated gene or protein expression between AAV patients and healthy controls. Furthermore, IRG and IFN regulated protein expression did not correlate with clinical measurements of disease activity in AAV patients. Thus, we conclude that systemic type I IFN responses are not key drivers of AAV pathogenesis and AAV should not be considered a type I interferonopathy.

Poly-L-Lysine Induces Fibrosis on Alginate Microcapsules via the Induction of Cytokines

2001 ◽  
Vol 10 (3) ◽  
pp. 263-275 ◽  
Author(s):  
Berit L. Strand ◽  
Liv Ryan ◽  
Peter In't Veld ◽  
Bård Kulseng ◽  
Anne Mari Rokstad ◽  
...  
Keyword(s):  
Lipid A ◽  
Kinase Inhibitor ◽  
Inflammatory Responses ◽  
Type I Diabetes ◽  
Annexin V ◽  
Cell Types ◽  
P38 Map Kinase ◽  
Common Element ◽  
Type I ◽  
Inflammatory Reactions

Alginate – poly-l-lysine (PLL) microcapsules can be used for transplantation of insulin-producing cells for treatment of type I diabetes. In this work we wanted to study the inflammatory reactions against implanted microcapsules due to PLL. We have seen that by reducing the PLL layer, less overgrowth of the capsule is obtained. By incubating different cell types with PLL and afterwards measuring cell viability with MTT, we found massive cell death at concentrations of PLL higher than 10 μg/ml. Staining with annexin V and propidium iodide showed that PLL induced necrosis but not apoptosis. The proinflammatory cytokine, tumor necrosis factor (TNF), was detected in supernatants from monocytes stimulated with PLL. The TNF response was partly inhibited with antibodies against CD14, which is a well-known receptor for lipopolysaccharide (LPS). Bactericidal permeability increasing protein (BPI) and a lipid A analogue (B-975), which both inhibit LPS, did not inhibit PLL from stimulating monocytes to TNF production. This indicates that PLL and LPS bind to different sites on monocytes, but because they both are inhibited by a p38 MAP kinase inhibitor, they seem to have a common element in the signal transducing pathway. These results suggest that PLL may provoke inflammatory responses either directly or indirectly through its necrosis-inducing abilities. By combining soluble PLL and alginate both the toxic and TNF-inducing effects of PLL were reduced. The implications of these data are to use alginate microcapsules with low amounts of PLL for transplantation purposes.

scholarly journals 435 Autocrine IFN-k maintains baseline type I interferon responses in keratinocytes in a Tyk2 dependent manner

2016 ◽  
Vol 136 (9) ◽  
pp. S234
Author(s):  
M. Sarkar ◽  
L.C. Tsoi ◽  
X. Xing ◽  
L. Yun ◽  
P. Harms ◽  
...  
Keyword(s):  
Type I Interferon ◽  
Type I ◽  
Dependent Manner ◽  
Interferon Responses

scholarly journals Regulatory NLRs Control the RLR-Mediated Type I Interferon and Inflammatory Responses in Human Dendritic Cells

2018 ◽  
Vol 9 ◽  
Author(s):  
Tünde Fekete ◽  
Dora Bencze ◽  
Attila Szabo ◽  
Eszter Csoma ◽  
Tamas Biro ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Inflammatory Responses ◽  
Type I Interferon ◽  
Type I ◽  
Human Dendritic Cells
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