scholarly journals The transcription factor Spi-B regulates human plasmacytoid dendritic cell survival through direct induction of the antiapoptotic gene BCL2-A1

Blood ◽  
2012 ◽  
Vol 119 (22) ◽  
pp. 5191-5200 ◽  
Author(s):  
Julien J. Karrich ◽  
Melania Balzarolo ◽  
Heike Schmidlin ◽  
Marion Libouban ◽  
Maho Nagasawa ◽  
...  

Plasmacytoid dendritic cells (pDCs) selectively express Toll-like receptor (TLR)–7 and TLR-9, which allow them to rapidly secrete massive amounts of type I interferons after sensing nucleic acids derived from viruses or bacteria. It is not completely understood how development and function of pDCs are controlled at the transcriptional level. One of the main factors driving pDC development is the ETS factor Spi-B, but little is known about its target genes. Here we demonstrate that Spi-B is crucial for the differentiation of hematopoietic progenitor cells into pDCs by controlling survival of pDCs and its progenitors. In search for Spi-B target genes, we identified the antiapoptotic gene Bcl2-A1 as a specific and direct target gene, thereby consolidating the critical role of Spi-B in cell survival.

2019 ◽  
Author(s):  
S Ehrlich ◽  
K Wild ◽  
M Smits ◽  
K Zoldan ◽  
M Hofmann ◽  
...  

2018 ◽  
Vol 97 (8) ◽  
pp. 893-900 ◽  
Author(s):  
J. Papinska ◽  
H. Bagavant ◽  
G.B. Gmyrek ◽  
M. Sroka ◽  
S. Tummala ◽  
...  

Sjögren syndrome (SS), a chronic autoimmune disorder causing dry mouth, adversely affects the overall oral health in patients. Activation of innate immune responses and excessive production of type I interferons (IFNs) play a critical role in the pathogenesis of this disorder. Recognition of nucleic acids by cytosolic nucleic acid sensors is a major trigger for the induction of type I IFNs. Upon activation, cytosolic DNA sensors can interact with the stimulator of interferon genes (STING) protein, and activation of STING causes increased expression of type I IFNs. The role of STING activation in SS is not known. In this study, to investigate whether the cytosolic DNA sensing pathway influences SS development, female C57BL/6 mice were injected with a STING agonist, dimethylxanthenone-4-acetic acid (DMXAA). Salivary glands (SGs) were studied for gene expression and inflammatory cell infiltration. SG function was evaluated by measuring pilocarpine-induced salivation. Sera were analyzed for cytokines and autoantibodies. Primary SG cells were used to study the expression and activation of STING. Our data show that systemic DMXAA treatment rapidly induced the expression of Ifnb1, Il6, and Tnfa in the SGs, and these cytokines were also elevated in circulation. In contrast, increased Ifng gene expression was dominantly detected in the SGs. The type I innate lymphoid cells present within the SGs were the major source of IFN-γ, and their numbers increased significantly within 3 d of treatment. STING expression in SGs was mainly observed in ductal and interstitial cells. In primary SG cells, DMXAA activated STING and induced IFN-β production. The DMXAA-treated mice developed autoantibodies, sialoadenitis, and glandular hypofunction. Our study demonstrates that activation of the STING pathway holds the potential to initiate SS. Thus, apart from viral infections, conditions that cause cellular perturbations and accumulation of host DNA within the cytosol should also be considered as possible triggers for SS.


2020 ◽  
Vol 94 (7) ◽  
Author(s):  
Dan Li ◽  
Wenping Yang ◽  
Yi Ru ◽  
Jingjing Ren ◽  
Xiangtao Liu ◽  
...  

ABSTRACT The virus-induced signaling adaptor (VISA) complex plays a critical role in the innate immune response to RNA viruses. However, the mechanism of VISA complex formation remains unclear. Here, we demonstrate that thioredoxin 2 (TRX2) interacts with VISA at mitochondria both in vivo and in vitro. Knockdown and knockout of TRX2 enhanced the formation of the VISA-associated complex, as well as virus-triggered activation of interferon regulatory factor 3 (IRF3) and transcription of the interferon beta 1 (IFNB1) gene. TRX2 inhibits the formation of VISA aggregates by repressing reactive oxygen species (ROS) production, thereby disrupting the assembly of the VISA complex. Furthermore, our data suggest that the C93 residue of TRX2 is essential for inhibition of VISA aggregation, whereas the C283 residue of VISA is required for VISA aggregation. Collectively, these findings uncover a novel mechanism of TRX2 that negatively regulates VISA complex formation. IMPORTANCE The VISA-associated complex plays pivotal roles in inducing type I interferons (IFNs) and eliciting the innate antiviral response. Many host proteins are identified as VISA-associated-complex proteins, but how VISA complex formation is regulated by host proteins remains enigmatic. We identified the TRX2 protein as an important regulator of VISA complex formation. Knockout of TRX2 increases virus- or poly(I·C)-triggered induction of type I IFNs at the VISA level. Mechanistically, TRX2 inhibits the production of ROS at its C93 site, which impairs VISA aggregates at its C283 site, and subsequently impedes the assembly of the VISA complex. Our findings suggest that TRX2 plays an important role in the regulation of VISA complex assembly.


Author(s):  
Sara Vitale ◽  
Valentina Russo ◽  
Beatrice Dettori ◽  
Cecilia Palombi ◽  
Denis Baev ◽  
...  

Abstract The type I interferons are central to a vast array of immunological functions. The production of these immune-modulatory molecules is initiated at the early stages of the innate immune responses and, therefore, plays a dominant role in shaping downstream events in both innate and adaptive immunity. Indeed, the major role of IFN-α/β is the induction of priming states, relevant for the functional differentiation of T lymphocyte subsets. Among T-cell subtypes, the CD4+CD25+Foxp3+ T regulatory cells (Tregs) represent a specialized subset of CD4+ T cells with a critical role in maintaining peripheral tolerance and immune homeostasis. Although the role of type I interferons in maintaining the function of thymus-derived Tregs has been previously described, the direct contribution of these innate factors to peripheral Treg (pTreg) and induced Treg (iTreg) differentiation and suppressive function is still unclear. We now show that, under tolerogenic conditions, IFN-α/β play a critical role in antigen-specific and also polyclonal naive CD4+ T-cell conversion into peripheral antigen-specific CD4+CD25+Foxp3+ Tregs and inhibit CD4+ T helper (Th) cell expansion in mice. While type I interferons sustain the expression and the activation of the transcription master regulators Foxp3, Stat3 and Stat5, these innate molecules reciprocally inhibit Th17 cell differentiation. Altogether, these results indicate a new pivotal role of IFN-α/β on pTreg differentiation and induction of peripheral tolerance, which may have important implications in the therapeutic control of inflammatory disorders, such as of autoimmune diseases.


Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 1001-1001
Author(s):  
Valentina Nardi ◽  
Olaia Naveiras ◽  
Mohammad Azam ◽  
George Q. Daley

Abstract Until recently, the mainstay of Chronic Myelogenous Leukemia (CML) therapy was Interferon (IFN) alpha, which in a minority of patients induces long lasting cytogenetic remission. While the exact mechanism of action of IFN alpha in CML is still obscure, it is clear that the clinical response to IFN alpha correlates with immune system reactivity against leukemic clones. As minimal molecular disease often persists despite the use of imatinib and new Bcr-Abl inhibitors, immunotherapy remains an appealing adjunct to molecularly targeted inhibitors in CML therapy. We have shown that IRF8/ICSBP (Interferon Consensus Sequence Binding Protein) expression in Bcr-Abl transformed cells prevents their capacity to form a lethal leukemia when injected into mice, and that this protection is mediated by a long-lasting and potent CD8+ response against unknown epitopes on the leukemic cells. We hypothesized that the protection mediated by IRF8/ICSBP might be related to the anti-leukemic effects of IFN alpha. We now find that Type I IFNs like IFN alpha regulate IRF8/ICSBP expression in mouse and human cells and in Bcr-Abl transformed cells. Furthermore, type I IFNs can substitute for ICSBP in inducing the anti-leukemic immunity against Bcr-Abl transformed cells. Transcriptional profiling of cells expressing ICSBP, Bcr-Abl, or both ICSBP and Bcr-Abl identified two chemokines, CCL6 and CCL9, which were associated with the immune protection induced by IRF8/ICSBP expression. Type I IFNs and IRF8/ICSBP induce the expression of these chemokines in cells transformed with Bcr-Abl. RNAi-mediated inhibition experiments in our mouse model of CML show that these chemokines are required for the IRF8/ICSBP-mediated CD8+ anti-leukemic response to the Bcr-Abl transformed cells, suggesting that these chemokines could be exploited for immunotherapy in combination with existing Bcr-Abl peptide vaccines.


2010 ◽  
Vol 84 (13) ◽  
pp. 6549-6563 ◽  
Author(s):  
Erin L. Lousberg ◽  
Cara K. Fraser ◽  
Michael G. Tovey ◽  
Kerrilyn R. Diener ◽  
John D. Hayball

ABSTRACT Type I interferons (IFNs) are considered to be important mediators of innate immunity due to their inherent antiviral activity, ability to drive the transcription of a number of genes involved in viral clearance, and their role in the initiation of innate and adaptive immune responses. Due to the central role of type I IFNs, we sought to determine their importance in the generation of immunity to a recombinant vaccine vector fowlpox virus (FPV). In analyzing the role of type I IFNs in immunity to FPV, we show that they are critical to the secretion of a number of innate and proinflammatory cytokines, including type I IFNs themselves as well as interleukin-12 (IL-12), tumor necrosis factor-alpha (TNF-α), IL-6, and IL-1β, and that deficiency leads to enhanced virus-mediated antigen expression. Interestingly, however, type I IFNs were not required for adaptive immune responses to recombinant FPV even though plasmacytoid dendritic cells (pDCs), the primary producers of type I IFNs, have been shown to be requisite for this to occur. Furthermore, we provide evidence that the importance of pDCs may lie in their ability to capture and present virally derived antigen to T cells rather than in their capacity as professional type I IFN-producing cells.


2010 ◽  
Vol 70 (7) ◽  
pp. 2595-2603 ◽  
Author(s):  
Arnold I. Chin ◽  
Andrea K. Miyahira ◽  
Anthony Covarrubias ◽  
Juli Teague ◽  
Beichu Guo ◽  
...  

2016 ◽  
Vol 36 (7) ◽  
pp. 1124-1135 ◽  
Author(s):  
Yuliya V. Katlinskaya ◽  
Kanstantsin V. Katlinski ◽  
Audrey Lasri ◽  
Ning Li ◽  
Daniel P. Beiting ◽  
...  

Wnt pathway-driven proliferation and renewal of the intestinal epithelium must be tightly controlled to prevent development of cancer and barrier dysfunction. Although type I interferons (IFN) produced in the gut under the influence of microbiota are known for their antiproliferative effects, the role of these cytokines in regulating intestinal epithelial cell renewal is largely unknown. Here we report a novel role for IFN in the context of intestinal knockout of casein kinase 1α (CK1α), which controls the ubiquitination and degradation of both β-catenin and the IFNAR1 chain of the IFN receptor. Ablation of CK1α leads to the activation of both β-catenin and IFN pathways and prevents the unlimited proliferation of intestinal epithelial cells despite constitutive β-catenin activity. IFN signaling contributes to the activation of the p53 pathway and the appearance of apoptotic and senescence markers in the CK1α-deficient gut. Concurrent genetic ablation of CK1α and IFNAR1 leads to intestinal hyperplasia, robust attenuation of apoptosis, and rapid and lethal loss of barrier function. These data indicate that IFN play an important role in controlling the proliferation and function of the intestinal epithelium in the context of β-catenin activation.


2021 ◽  
Vol 12 ◽  
Author(s):  
Guanghui Qian ◽  
Liyan Zhu ◽  
Gen Li ◽  
Ying Liu ◽  
Zimu Zhang ◽  
...  

Viral infectious diseases pose a great challenge to human health around the world. Type I interferons (IFN-Is) function as the first line of host defense and thus play critical roles during virus infection by mediating the transcriptional induction of hundreds of genes. Nevertheless, overactive cytokine immune responses also cause autoimmune diseases, and thus, tight regulation of the innate immune response is needed to achieve viral clearance without causing excessive immune responses. Emerging studies have recently uncovered that the ubiquitin system, particularly deubiquitinating enzymes (DUBs), plays a critical role in regulating innate immune responses. In this review, we highlight recent advances on the diverse mechanisms of human DUBs implicated in IFN-I signaling. These DUBs function dynamically to calibrate host defenses against various virus infections by targeting hub proteins in the IFN-I signaling transduction pathway. We also present a future perspective on the roles of DUB-substrate interaction networks in innate antiviral activities, discuss the promises and challenges of DUB-based drug development, and identify the open questions that remain to be clarified. Our review provides a comprehensive description of DUBs, particularly their differential mechanisms that have evolved in the host to regulate IFN-I-signaling-mediated antiviral responses.


2021 ◽  
Vol 33 (4) ◽  
pp. 305
Author(s):  
Kai Josef Endriß ◽  
Marie Margarete Meyerholz ◽  
Teresa Fischbach ◽  
Lutz Brimmers ◽  
Christiane Pfarrer ◽  
...  

In cattle, maternal recognition of early pregnancy depends on the effects of the embryonic signal interferon (IFN)-τ. IFN-stimulated genes have been upregulated in the maternal liver during early pregnancy. In this study, primary hepatocyte cell culture models were evaluated for their suitability to test Type I IFN effects invitro. The expression of target genes (interferon-stimulated gene 15 (ISG-15), interferon-induced GTP-binding protein (MX-1), C-X-C motif chemokine 10 (CXCL-10), CXCL-5, insulin-like growth factor 1 (IGF-1), IGF binding protein 2 (IGFBP-2)) was measured using reverse transcription–quantitative polymerase chain reaction in hepatocytes from monoculture or in indirect coculture with Kupffer cells (HKCid) on Days 1, 2, 3 and 4 of culture (n=21 donor cows). Gene expression was also measured on Day 4 after challenging the cultures with recombinant IFNτ, IFNα, progesterone (P4), IFNτ+IFNα or IFNτ+P4 for 6h. A significant increase in the mRNA expression of target genes in hepatocytes was shown in response to stimulation with IFNτ. The Kupffer cells in coculture did not influence the effects of IFNτ in hepatocytes. In conclusion, primary bovine hepatocyte cultures are suitable for stimulation experiments with Type I IFNs and as an extrauterine model for embryo–maternal communication. The proposed endocrine action of IFNτ in the liver may affect maternal metabolism and immune function in the liver.


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