scholarly journals Type I Interferons in Bacterial Infections: A Balancing Act

2016 ◽  
Vol 7 ◽  
Author(s):  
Pavel Kovarik ◽  
Virginia Castiglia ◽  
Masa Ivin ◽  
Florian Ebner
eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Daisy X Ji ◽  
Kristen C Witt ◽  
Dmitri I Kotov ◽  
Shally R Margolis ◽  
Alexander Louie ◽  
...  

Type I interferons (IFNs) are essential for anti-viral immunity, but often impair protective immune responses during bacterial infections. An important question is how type I IFNs are strongly induced during viral infections, and yet are appropriately restrained during bacterial infections. The Super susceptibility to tuberculosis 1 (Sst1) locus in mice confers resistance to diverse bacterial infections. Here we provide evidence that Sp140 is a gene encoded within the Sst1 locus that represses type I IFN transcription during bacterial infections. We generated Sp140-/- mice and find they are susceptible to infection by Legionella pneumophila and Mycobacterium tuberculosis. Susceptibility of Sp140-/- mice to bacterial infection was rescued by crosses to mice lacking the type I IFN receptor (Ifnar-/-). Our results implicate Sp140 as an important negative regulator of type I IFNs that is essential for resistance to bacterial infections.


Cells ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 74
Author(s):  
Erika S. Guimarães ◽  
Fabio V. Marinho ◽  
Nina M. G. P. de Queiroz ◽  
Maísa M. Antunes ◽  
Sergio C. Oliveira

The early detection of bacterial pathogens through immune sensors is an essential step in innate immunity. STING (Stimulator of Interferon Genes) has emerged as a key mediator of inflammation in the setting of infection by connecting pathogen cytosolic recognition with immune responses. STING detects bacteria by directly recognizing cyclic dinucleotides or indirectly by bacterial genomic DNA sensing through the cyclic GMP-AMP synthase (cGAS). Upon activation, STING triggers a plethora of powerful signaling pathways, including the production of type I interferons and proinflammatory cytokines. STING activation has also been associated with the induction of endoplasmic reticulum (ER) stress and the associated inflammatory responses. Recent reports indicate that STING-dependent pathways participate in the metabolic reprogramming of macrophages and contribute to the establishment and maintenance of a robust inflammatory profile. The induction of this inflammatory state is typically antimicrobial and related to pathogen clearance. However, depending on the infection, STING-mediated immune responses can be detrimental to the host, facilitating bacterial survival, indicating an intricate balance between immune signaling and inflammation during bacterial infections. In this paper, we review recent insights regarding the role of STING in inducing an inflammatory profile upon intracellular bacterial entry in host cells and discuss the impact of STING signaling on the outcome of infection. Unraveling the STING-mediated inflammatory responses can enable a better understanding of the pathogenesis of certain bacterial diseases and reveal the potential of new antimicrobial therapy.


Author(s):  
Daisy X. Ji ◽  
Kristen C. Witt ◽  
Dmitri I. Kotov ◽  
Shally R. Margolis ◽  
Alexander Louie ◽  
...  

AbstractType I interferons (IFNs) are essential for anti-viral immunity, but often impair protective immune responses during bacterial infections. How type I IFNs are strongly induced during viral infections, and yet are appropriately restrained during bacterial infections, remains poorly understood. The Super susceptibility to tuberculosis 1 (Sst1) locus in mice confers resistance to many bacterial infections. Here we provide evidence that Sp140 is a gene encoded within the Sst1 locus that functions to repress the expression of type I IFNs during bacterial infections. We generated Sp140−/− mice and find they are susceptible to infection by diverse bacteria, including Listeria monocytogenes, Legionella pneumophila, and Mycobacterium tuberculosis. Susceptibility of Sp140−/− mice to bacterial infection was rescued by crosses to mice lacking the type I IFN receptor (Ifnar−/−). Our results implicate Sp140 as an important repressor of type I IFNs that is essential for resistance to bacterial infections.


Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 785
Author(s):  
Alessandra Tesser ◽  
Giulia Maria Piperno ◽  
Alessia Pin ◽  
Elisa Piscianz ◽  
Valentina Boz ◽  
...  

Cytoplasmic nucleic acids sensing through cGAS-STING-TBK1 pathway is crucial for the production of antiviral interferons (IFNs). IFN production can also be induced by lipopolysaccharide (LPS) stimulation through Toll-like receptor 4 (TLR4) in appropriate conditions. Of note, both IFN production and dysregulated LPS-response could play a role in the pathogenesis of Systemic Lupus Erythematosus (SLE). Indeed, LPS can trigger SLE in lupus-prone mice and bacterial infections can induce disease flares in human SLE. However, the interactions between cGAS and TLR4 pathways to IFNs have been poorly investigated. To address this issue, we studied LPS-stimulation in cellular models with a primed cGAS-STING-TBK1 pathway. cGAS-stimulation was naturally sustained by undigested self-nucleic acids in fibroblasts from DNase2-deficiency interferonopathy, whilst it was pharmacologically obtained by cGAMP-stimulation in THP1 cells and murine bone marrow-derived dendritic cells. We showed that cells with a primed cGAS-STING-TBK1 pathway displayed enhanced IFNs production after TLR4-challenge. STING-inhibition did not affect IFN production after LPS alone, but prevented the amplified IFN production in cGAMP-primed cells, suggesting that functional STING is required for priming-dependent enhancement. Furthermore, we speculated that an increased PIK3AP1 expression in DNase2-deficient fibroblasts may link cGAMP-priming with increased LPS-induced IFN production. We showed that both the hyper-expression of PIK3API and the enhanced LPS-induced IFN production can be contrasted by STING inhibitors. Our results may explain how bacterial LPS can synergize with cGAS-pathway in promoting the development of SLE-like autoimmunity.


2007 ◽  
Vol 204 (5) ◽  
pp. 1107-1118 ◽  
Author(s):  
Xiaoming Zhang ◽  
Edith Deriaud ◽  
Xinan Jiao ◽  
Deborah Braun ◽  
Claude Leclerc ◽  
...  

Newborns and infants are highly susceptible to viral and bacterial infections, but the underlying mechanism remains poorly understood. We show that neonatal B cells effectively control the production of proinflammatory cytokines by both neonatal plasmacytoid and conventional dendritic cells, in an interleukin (IL) 10–dependent manner, after Toll-like receptor (TLR) 9 triggering. This antiinflammatory property of neonatal B cells may extend to other TLR agonists (Pam3CSK4, lipopolysaccharide, and R848) and viruses. In the absence of B cells or of CD5+ B cell subsets, neonatal mice developed stronger inflammatory responses and became lethally susceptible to CpG challenge after galactosamine sensitization, whereas wild-type (WT) mice were resistant. Paradoxically, interferon (IFN)-α/β enhanced the inflammatory response to CpG challenge in adult mice, whereas they helped to control neonatal acute inflammation by stimulating the secretion of IL-10 by neonatal B cells. Finally, WT neonatal B cells rescued IL-10−/− neonates from a lethal CpG challenge, whereas IFN-α/β receptor–deficient B cells did not. Our results show that type I IFNs support a negative regulatory role of neonatal B cells on TLR-mediated inflammation, with important implications for neonatal inflammation and infection.


2017 ◽  
Vol 2017 ◽  
pp. 1-17 ◽  
Author(s):  
Deann T. Snyder ◽  
Jodi F. Hedges ◽  
Mark A. Jutila

Type I interferons represent a unique and complex group of cytokines, serving many purposes during innate and adaptive immunity. Discovered in the context of viral infections, type I IFNs are now known to have myriad effects in infectious and autoimmune disease settings. Type I IFN signaling during bacterial infections is dependent on many factors including whether the infecting bacterium is intracellular or extracellular, as different signaling pathways are activated. As such, the repercussions of type I IFN induction can positively or negatively impact the disease outcome. This review focuses on type I IFN induction and downstream consequences during infection with the following intracellular bacteria:Chlamydia trachomatis,Listeria monocytogenes,Mycobacterium tuberculosis,Salmonella entericaserovar Typhimurium,Francisella tularensis,Brucella abortus,Legionella pneumophila, andCoxiella burnetii. Intracellular bacterial infections are unique because the bacteria must avoid, circumvent, and even co-opt microbial “sensing” mechanisms in order to reside and replicate within a host cell. Furthermore, life inside a host cell makes intracellular bacteria more difficult to target with antibiotics. Because type I IFNs are important immune effectors, modulating this pathway may improve disease outcomes. But first, it is critical to understand the context-dependent effects of the type I IFN pathway in intracellular bacterial infections.


1999 ◽  
Vol 189 (3) ◽  
pp. 521-530 ◽  
Author(s):  
Philippa Marrack ◽  
John Kappler ◽  
Tom Mitchell

Antigen injection into animals causes antigen-specific T cells to become activated and, rapidly thereafter, die. This antigen-induced death is inhibited by inflammation. To find out how inflammation has this effect, various cytokines were tested for their ability to interfere with the rapid death of activated T cells. T cells were activated in vivo, isolated, and cultured with the test reagents. Two groups of cytokines were active, members of the interleukin 2 family and the interferons (IFNs) α and β. This activity of IFN-α/β has not been described previously. It was due to direct effects of the IFNs on the T cells and was not mediated by induction of a second cytokine such as interleukin 15. IFN-γ did not slow the death of activated T cells, and therefore the activity of IFN-α/β was not mediated only by activation of Stat 1, a protein that is affected by both classes of IFN. IFN-α/β did not raise the levels of Bcl-2 or Bcl-XL in T cells. Therefore, their activity was distinct from that of members of the interleukin 2 family or CD28 engagement. Since IFN-α/β are very efficiently generated in response to viral and bacterial infections, these molecules may be among the signals that the immune system uses to prevent activated T cell death during infections.


2010 ◽  
Vol 79 (2) ◽  
pp. 688-694 ◽  
Author(s):  
John-Demian Sauer ◽  
Katia Sotelo-Troha ◽  
Jakob von Moltke ◽  
Kathryn M. Monroe ◽  
Chris S. Rae ◽  
...  

ABSTRACTType I interferons (IFNs) are central regulators of the innate and adaptive immune responses to viral and bacterial infections. Type I IFNs are induced upon cytosolic detection of microbial nucleic acids, including DNA, RNA, and the bacterial second messenger cyclic-di-GMP (c-di-GMP). In addition, a recent study demonstrated that the intracellular bacterial pathogenListeria monocytogenesstimulates a type I IFN response due to cytosolic detection of bacterially secreted c-di-AMP. The transmembrane signaling adaptor Sting (Tmem173, Mita, Mpys, Eris) has recently been implicated in the induction of type I IFNs in response to cytosolic DNA and/or RNA. However, the role of Sting in response to purified cyclic dinucleotides or duringin vivo L. monocytogenesinfection has not been addressed. In order to identify genes important in the innate immune response, we have been conducting a forward genetic mutagenesis screen in C57BL/6 mice using the mutagenN-ethyl-N-nitrosourea (ENU). Here we describe a novel mutant mouse strain,Goldenticket(Gt), that fails to produce type I IFNs uponL. monocytogenesinfection. By genetic mapping and complementation experiments, we found thatGtmice harbor a single nucleotide variant (T596A) ofStingthat functions as a null allele and fails to produce detectable protein. Analysis of macrophages isolated fromGtmice revealed thatStingis absolutely required for the type I interferon response to both c-di-GMP and c-di-AMP. Additionally,Stingis required for the response to c-di-GMP andL. monocytogenes in vivo. Our results provide new functions forStingin the innate interferon response to pathogens.


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