101
|
Margolis SR, Wilson SC, Vance RE. Evolutionary Origins of cGAS-STING Signaling. Trends Immunol 2017; 38:733-743. [DOI: 10.1016/j.it.2017.03.004] [Citation(s) in RCA: 149] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 03/19/2017] [Accepted: 03/20/2017] [Indexed: 12/25/2022]
|
102
|
Molecular requirements for sensing of intracellular microbial nucleic acids by the innate immune system. Cytokine 2017; 98:4-14. [DOI: 10.1016/j.cyto.2016.10.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Accepted: 10/11/2016] [Indexed: 12/24/2022]
|
103
|
Skyberg JA, Lacey CA. Hematopoietic MyD88 and IL-18 are essential for IFN-γ-dependent restriction of type A Francisella tularensis infection. J Leukoc Biol 2017; 102:1441-1450. [PMID: 28951422 DOI: 10.1189/jlb.4a0517-179r] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 08/03/2017] [Accepted: 08/29/2017] [Indexed: 12/11/2022] Open
Abstract
Francisella tularensis is a highly infectious intracellular bacterium that causes the potentially fatal disease tularemia. We used mice with conditional MyD88 deficiencies to investigate cellular and molecular mechanisms by which MyD88 restricts type A F. tularensis infection. F. tularensis-induced weight loss was predominately dependent on MyD88 signaling in nonhematopoietic cells. In contrast, MyD88 signaling in hematopoietic cells, but not in myeloid and dendritic cells, was essential for control of F. tularensis infection in tissue. Myeloid and dendritic cell MyD88 deficiency also did not markedly impair cytokine production during infection. Although the production of IL-12 or -18 was not significantly reduced in hematopoietic MyD88-deficient mice, IFN-γ production was abolished in these animals. In addition, neutralization studies revealed that control of F. tularensis infection mediated by hematopoietic MyD88 was entirely dependent on IFN-γ. Although IL-18 production was not significantly affected by MyD88 deficiency, IL-18 was essential for IFN-γ production and restricted bacterial replication in an IFN-γ-dependent manner. Caspase-1 was also found to be partially necessary for the production of IL-18 and IFN-γ and for control of F. tularensis replication. Our collective data show that the response of leukocytes to caspase-1-dependent IL-18 via MyD88 is critical, whereas MyD88 signaling in myeloid and dendritic cells is dispensable for IFN-γ-dependent control of type A F. tularensis infection.
Collapse
Affiliation(s)
- Jerod A Skyberg
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, Missouri, USA; and .,Laboratory for Infectious Disease Research, University of Missouri, Columbia, Missouri, USA
| | - Carolyn A Lacey
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, Missouri, USA; and.,Laboratory for Infectious Disease Research, University of Missouri, Columbia, Missouri, USA
| |
Collapse
|
104
|
Ghosh S, Wallerath C, Covarrubias S, Hornung V, Carpenter S, Fitzgerald KA. The PYHIN Protein p205 Regulates the Inflammasome by Controlling Asc Expression. THE JOURNAL OF IMMUNOLOGY 2017; 199:3249-3260. [PMID: 28931603 DOI: 10.4049/jimmunol.1700823] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 08/22/2017] [Indexed: 11/19/2022]
Abstract
Members of the IFN-inducible PYHIN protein family, such as absent in melanoma-2 and IFN-γ-inducible protein (IFI)16, bind dsDNA and form caspase-1-activating inflammasomes that are important in immunity to cytosolic bacteria, DNA viruses, or HIV. IFI16 has also been shown to regulate transcription of type I IFNs during HSV infection. The role of other members of the PYHIN protein family in the regulation of immune responses is much less clear. In this study, we identified an immune-regulatory function for a member of the murine PYHIN protein family, p205 (also called Ifi205). Examination of immune responses induced by dsDNA and other microbial ligands in bone marrow-derived macrophages lacking p205 revealed that inflammasome activation by dsDNA, as well as ligands that engage the NLRP3 inflammasome, was severely compromised in these cells. Further analysis revealed that p205-knockdown cells showed reduced expression of apoptosis-associated speck-like molecule containing CARD domain (Asc) at the protein and RNA levels. p205 knockdown resulted in reduced binding of actively transcribing RNA polymerase II to the endogenous Asc gene, resulting in decreased transcription and processing of Asc pre-mRNA. Deletion of p205 in B16 melanoma cells using CRISPR/Cas9 showed a similar loss of Asc expression. Ectopic expression of p205 induced expression of an Asc promoter-luciferase reporter gene. Together, these findings suggest that p205 controls expression of Asc mRNA to regulate inflammasome responses. These findings expand on our understanding of immune-regulatory roles for the PYHIN protein family.
Collapse
Affiliation(s)
- Sreya Ghosh
- Program in Innate Immunity, Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01605
| | - Christina Wallerath
- Gene Center, Ludwig Maximilian University of Munich, Munich 81377, Germany.,Department of Biochemistry, Ludwig Maximilian University of Munich, Munich 81377, Germany; and
| | - Sergio Covarrubias
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064
| | - Veit Hornung
- Gene Center, Ludwig Maximilian University of Munich, Munich 81377, Germany.,Department of Biochemistry, Ludwig Maximilian University of Munich, Munich 81377, Germany; and
| | - Susan Carpenter
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064
| | - Katherine A Fitzgerald
- Program in Innate Immunity, Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01605;
| |
Collapse
|
105
|
Putzova D, Panda S, Härtlova A, Stulík J, Gekara NO. Subversion of innate immune responses by Francisella involves the disruption of TRAF3 and TRAF6 signalling complexes. Cell Microbiol 2017; 19. [PMID: 28745813 DOI: 10.1111/cmi.12769] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 07/20/2017] [Accepted: 07/21/2017] [Indexed: 12/13/2022]
Abstract
The success of pathogens depends on their ability to circumvent immune defences. Francisella tularensis is one of the most infectious bacteria known. The remarkable virulence of Francisella is believed to be due to its capacity to evade or subvert the immune system, but how remains obscure. Here, we show that Francisella triggers but concomitantly inhibits the Toll-like receptor, RIG-I-like receptor, and cytoplasmic DNA pathways. Francisella subverts these pathways at least in part by inhibiting K63-linked polyubiquitination and assembly of TRAF6 and TRAF3 complexes that control the transcriptional responses of pattern recognition receptors. We show that this mode of inhibition requires a functional type VI secretion system and/or the presence of live bacteria in the cytoplasm. The ability of Francisella to enter the cytosol while simultaneously inhibiting multiple pattern recognition receptor pathways may account for the notable capacity of this bacterium to invade and proliferate in the host without evoking a self-limiting innate immune response.
Collapse
Affiliation(s)
- Daniela Putzova
- Department of Molecular Biology, The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden.,Department of Molecular Pathology and Biology, Faculty of Military Health Sciences, University of Defense, Hradec Králové, Czech Republic
| | - Swarupa Panda
- Department of Molecular Biology, The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
| | - Anetta Härtlova
- Department of Molecular Biology, The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
| | - Jiří Stulík
- Department of Molecular Pathology and Biology, Faculty of Military Health Sciences, University of Defense, Hradec Králové, Czech Republic
| | - Nelson O Gekara
- Department of Molecular Biology, The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
| |
Collapse
|
106
|
AIM2-Like Receptors Positively and Negatively Regulate the Interferon Response Induced by Cytosolic DNA. mBio 2017; 8:mBio.00944-17. [PMID: 28679751 PMCID: PMC5573678 DOI: 10.1128/mbio.00944-17] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Cytosolic DNAs derived from retrotransposons serve as pathogen-associated molecular patterns for pattern recognition receptors (PRRs) that stimulate the induction of interferons (IFNs) and other cytokines, leading to autoimmune disease. Cyclic GMP-AMP synthase is one PRR that senses retrotransposon DNA, activating type I IFN responses through the stimulator of IFN genes (STING). Absent in melanoma 2 (AIM2)-like receptors (ALRs) have also been implicated in these pathways. Here we show that the mouse ALR IFI205 senses cytosolic retrotransposon DNA independently of cyclic GMP-AMP production. AIM2 antagonizes IFI205-mediated IFN induction activity by sequestering it from STING. We also found that the complement of genes located in the ALR locus in C57BL/6 and AIM2 knockout mice are different and unique, which has implications for interpretation of the sensing of pathogens in different mouse strains. Our data suggest that members of the ALR family are critical to the host IFN response to endogenous DNA.IMPORTANCE Autoimmune diseases like Aicardi-Goutières syndrome and lupus erythematosus arise when cells of the immune system become activated and attack host cells and tissues. We found that DNA generated by endogenous retroviruses and retroelements in inbred mice and mouse cells is recognized by several host proteins found in macrophages that are members of the ALR family and that these proteins both suppress and activate the pathways leading to the generation of cytokines and IFNs. We also show that there is great genetic diversity between different inbred mouse strains in the ALR genes, which might contribute to differential susceptibility to autoimmunity. Understanding how immune cells become activated is important to the control of disease.
Collapse
|
107
|
Francisella requires dynamic type VI secretion system and ClpB to deliver effectors for phagosomal escape. Nat Commun 2017. [PMID: 28621333 PMCID: PMC5481754 DOI: 10.1038/ncomms15853] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Francisella tularensis is an intracellular pathogen that causes the fatal zoonotic disease tularaemia. Critical for its pathogenesis is the ability of the phagocytosed bacteria to escape into the cell cytosol. For this, the bacteria use a non-canonical type VI secretion system (T6SS) encoded on the Francisella pathogenicity island (FPI). Here we show that in F. novicida T6SS assembly initiates at the bacterial poles both in vitro and within infected macrophages. T6SS dynamics and function depends on the general purpose ClpB unfoldase, which specifically colocalizes with contracted sheaths and is required for their disassembly. T6SS assembly depends on iglF, iglG, iglI and iglJ, whereas pdpC, pdpD, pdpE and anmK are dispensable. Importantly, strains lacking pdpC and pdpD are unable to escape from phagosome, activate AIM2 inflammasome or cause disease in mice. This suggests that PdpC and PdpD are T6SS effectors involved in phagosome rupture. The pathogenicity of Francisella species largely depends on their escape from phagosomes in macrophages, mediated by a type VI secretion system (T6SS). Here, the authors show dynamics of T6SS assembly and disassembly and identify the genes essential for phagosome escape and pathogenicity in mice.
Collapse
|
108
|
Regulation and function of the cGAS-STING pathway of cytosolic DNA sensing. Nat Immunol 2017; 17:1142-9. [PMID: 27648547 DOI: 10.1038/ni.3558] [Citation(s) in RCA: 1269] [Impact Index Per Article: 181.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Accepted: 08/16/2016] [Indexed: 02/08/2023]
Abstract
The recognition of microbial nucleic acids is a major mechanism by which the immune system detects pathogens. Cyclic GMP-AMP (cGAMP) synthase (cGAS) is a cytosolic DNA sensor that activates innate immune responses through production of the second messenger cGAMP, which activates the adaptor STING. The cGAS-STING pathway not only mediates protective immune defense against infection by a large variety of DNA-containing pathogens but also detects tumor-derived DNA and generates intrinsic antitumor immunity. However, aberrant activation of the cGAS pathway by self DNA can also lead to autoimmune and inflammatory disease. Thus, the cGAS pathway must be properly regulated. Here we review the recent advances in understanding of the cGAS-STING pathway, focusing on the regulatory mechanisms and roles of this pathway in heath and disease.
Collapse
|
109
|
Yuan J, Najafov A, Py BF. Roles of Caspases in Necrotic Cell Death. Cell 2017; 167:1693-1704. [PMID: 27984721 DOI: 10.1016/j.cell.2016.11.047] [Citation(s) in RCA: 204] [Impact Index Per Article: 29.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 11/13/2016] [Accepted: 11/23/2016] [Indexed: 12/15/2022]
Abstract
Caspases were originally identified as important mediators of inflammatory response and apoptosis. Recent discoveries, however, have unveiled their roles in mediating and suppressing two regulated forms of necrotic cell death, termed pyroptosis and necroptosis, respectively. These recent advances have significantly expanded our understanding of the roles of caspases in regulating development, adult homeostasis, and host defense response.
Collapse
Affiliation(s)
- Junying Yuan
- Department of Cell Biology, Harvard Medical School, 240 Longwood Ave., Boston, MA 02115, USA; Ludwig Cancer Center, Harvard Medical School, 240 Longwood Ave., Boston, MA 02115, USA.
| | - Ayaz Najafov
- Department of Cell Biology, Harvard Medical School, 240 Longwood Ave., Boston, MA 02115, USA; Ludwig Cancer Center, Harvard Medical School, 240 Longwood Ave., Boston, MA 02115, USA
| | - Bénédicte F Py
- CIRI, Inserm U1111, Université Claude Bernard Lyon 1, CNRS UMR5308, École Normale Supérieure de Lyon, Université de Lyon, 69007 Lyon, France
| |
Collapse
|
110
|
Chunfa L, Xin S, Qiang L, Sreevatsan S, Yang L, Zhao D, Zhou X. The Central Role of IFI204 in IFN-β Release and Autophagy Activation during Mycobacterium bovis Infection. Front Cell Infect Microbiol 2017; 7:169. [PMID: 28529930 PMCID: PMC5418236 DOI: 10.3389/fcimb.2017.00169] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 04/18/2017] [Indexed: 01/16/2023] Open
Abstract
Mycobacterium bovis (M. bovis) is the pathogen of animals and humans that can replicate in the phagosomes of myeloid cells. Cytosolic detection of bacterial products plays a crucial role in initiating the innate immune response, including autophagy activation and interferon-β (IFN-β) release. Although IFN-β release and autophagy activation have been reported during mycobacterium infection, the mechanisms underlying remains poorly defined. Here, we demonstrated that IFN-β release increases in macrophages exposed to M. bovis and this requires the activation of the DNA sensor of interferon-γ inducible protein 204 (IFI204). Knockdown of the IFI204 in immortalized and primary murine macrophages blocked IFN-β production and autophagy marker LC3 expression. Thus, our results indicate that the IFI204 is an important sensor for innate immune responses of M. bovis infection.
Collapse
Affiliation(s)
- Liu Chunfa
- State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural UniversityBeijing, China
| | - Sun Xin
- State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural UniversityBeijing, China
| | - Li Qiang
- Department of Veterinary Medicine, College of Agriculture, Ningxia UniversityYinchuan, China
| | - Srinand Sreevatsan
- Department of Veterinary Population Medicine, College of Veterinary Medicine, University of MinnesotaSaint Paul, MN, USA
| | - Lifeng Yang
- State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural UniversityBeijing, China
| | - Deming Zhao
- State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural UniversityBeijing, China
| | - Xiangmei Zhou
- State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural UniversityBeijing, China
| |
Collapse
|
111
|
Man SM, Karki R, Kanneganti TD. Molecular mechanisms and functions of pyroptosis, inflammatory caspases and inflammasomes in infectious diseases. Immunol Rev 2017; 277:61-75. [PMID: 28462526 PMCID: PMC5416822 DOI: 10.1111/imr.12534] [Citation(s) in RCA: 1068] [Impact Index Per Article: 152.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cell death is a fundamental biological phenomenon that is essential for the survival and development of an organism. Emerging evidence also indicates that cell death contributes to immune defense against infectious diseases. Pyroptosis is a form of inflammatory programmed cell death pathway activated by human and mouse caspase-1, human caspase-4 and caspase-5, or mouse caspase-11. These inflammatory caspases are used by the host to control bacterial, viral, fungal, or protozoan pathogens. Pyroptosis requires cleavage and activation of the pore-forming effector protein gasdermin D by inflammatory caspases. Physical rupture of the cell causes release of the pro-inflammatory cytokines IL-1β and IL-18, alarmins and endogenous danger-associated molecular patterns, signifying the inflammatory potential of pyroptosis. Here, we describe the central role of inflammatory caspases and pyroptosis in mediating immunity to infection and clearance of pathogens.
Collapse
Affiliation(s)
- Si Ming Man
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Rajendra Karki
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | | |
Collapse
|
112
|
Snyder DT, Hedges JF, Jutila MA. Getting "Inside" Type I IFNs: Type I IFNs in Intracellular Bacterial Infections. J Immunol Res 2017; 2017:9361802. [PMID: 28529959 PMCID: PMC5424489 DOI: 10.1155/2017/9361802] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2017] [Revised: 03/20/2017] [Accepted: 03/27/2017] [Indexed: 12/23/2022] Open
Abstract
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 enterica serovar Typhimurium, Francisella tularensis, Brucella abortus, Legionella pneumophila, and Coxiella 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.
Collapse
Affiliation(s)
- Deann T. Snyder
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
| | - Jodi F. Hedges
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
| | - Mark A. Jutila
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
| |
Collapse
|
113
|
Mitochondrial DNA in innate immune responses and inflammatory pathology. Nat Rev Immunol 2017; 17:363-375. [PMID: 28393922 DOI: 10.1038/nri.2017.21] [Citation(s) in RCA: 607] [Impact Index Per Article: 86.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Mitochondrial DNA (mtDNA) - which is well known for its role in oxidative phosphorylation and maternally inherited mitochondrial diseases - is increasingly recognized as an agonist of the innate immune system that influences antimicrobial responses and inflammatory pathology. On entering the cytoplasm, extracellular space or circulation, mtDNA can engage multiple pattern-recognition receptors in cell-type- and context-dependent manners to trigger pro-inflammatory and type I interferon responses. Here, we review the expanding research field of mtDNA in innate immune responses to highlight new mechanistic insights and discuss the physiological and pathological relevance of this exciting area of mitochondrial biology.
Collapse
|
114
|
Abstract
Inflammasomes are multiprotein complexes whose primary function is to activate caspase-1, which allows the cleavage of pro-IL-1β and pro-IL-18 to their mature forms. The production of these cytokines has been shown to be critical for host defense as well as the maintenance of intestinal homeostasis and protection against pathologic intestinal inflammation. More recently, there has been growing evidence that inflammasomes are also capable of regulating the composition of the gut microbiota in mice models, which has significant implications for intestinal health and disease. Specifically, the absence of inflammasome components has been associated with pathologic alterations in the gut microbiota, or dysbiosis, that can result in increased susceptibility to colitis and tumorigenesis. In this review, evidence that inflammasome signaling is important for promoting a healthful microbiome and potential mechanisms by which inflammasomes modulate the gut microbiome will be presented. A better understanding of the function of inflammasomes in microbiome regulation may lead to the development of effective strategies for the prevention and treatment of diseases driven by dysbiosis.
Collapse
Affiliation(s)
- Grace Y Chen
- Division of Hematology & Oncology, Department of Internal Medicine, 1500 East Medical Center Drive, Ann Arbor, MI 48109, United States.
| |
Collapse
|
115
|
Abstract
During viral and bacterial infections, pathogen-derived cytosolic nucleic acids are recognized by the intracellular RNA sensors retinoic acid-inducible gene I and melanoma-differentiated gene 5 and intracellular DNA sensors, including cyclic-di-GMP-AMP synthase, absent in melanoma 2, interferon (IFN)-gamma inducible protein 16, polymerase III, and so on. Binding of intracellular nucleic acids to these sensors activates downstream signaling cascades, resulting in the production of type I IFNs and pro-inflammatory cytokines to induce appropriate systematic immune responses. While these sensors also recognize endogenous nucleic acids and activate immune responses, they can discriminate between self- and non-self-nucleic acids. However, dysfunction of these sensors or failure of regulatory mechanisms causes aberrant activation of immune response and autoimmune disorders. In this review, we focus on how intracellular immune sensors recognize exogenous nucleic acids and activate the innate immune system, and furthermore, how autoimmune diseases result from dysfunction of these sensors.
Collapse
Affiliation(s)
- Daisuke Ori
- a Laboratory of Molecular Immunobiology , Graduate School of Biological Sciences, Nara Institute of Science and Technology (NAIST), Takayama-cho , Ikoma , Nara , Japan
| | - Motoya Murase
- a Laboratory of Molecular Immunobiology , Graduate School of Biological Sciences, Nara Institute of Science and Technology (NAIST), Takayama-cho , Ikoma , Nara , Japan
| | - Taro Kawai
- a Laboratory of Molecular Immunobiology , Graduate School of Biological Sciences, Nara Institute of Science and Technology (NAIST), Takayama-cho , Ikoma , Nara , Japan
| |
Collapse
|
116
|
Almine JF, O'Hare CAJ, Dunphy G, Haga IR, Naik RJ, Atrih A, Connolly DJ, Taylor J, Kelsall IR, Bowie AG, Beard PM, Unterholzner L. IFI16 and cGAS cooperate in the activation of STING during DNA sensing in human keratinocytes. Nat Commun 2017; 8:14392. [PMID: 28194029 PMCID: PMC5316833 DOI: 10.1038/ncomms14392] [Citation(s) in RCA: 226] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 12/22/2016] [Indexed: 02/07/2023] Open
Abstract
Many human cells can sense the presence of exogenous DNA during infection though the cytosolic DNA receptor cyclic GMP-AMP synthase (cGAS), which produces the second messenger cyclic GMP-AMP (cGAMP). Other putative DNA receptors have been described, but whether their functions are redundant, tissue-specific or integrated in the cGAS-cGAMP pathway is unclear. Here we show that interferon-γ inducible protein 16 (IFI16) cooperates with cGAS during DNA sensing in human keratinocytes, as both cGAS and IFI16 are required for the full activation of an innate immune response to exogenous DNA and DNA viruses. IFI16 is also required for the cGAMP-induced activation of STING, and interacts with STING to promote STING phosphorylation and translocation. We propose that the two DNA sensors IFI16 and cGAS cooperate to prevent the spurious activation of the type I interferon response.
Collapse
Affiliation(s)
- Jessica F. Almine
- Division of Cell Signalling and Immunology, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster LA1 4YQ, UK
| | - Craig A. J. O'Hare
- Division of Cell Signalling and Immunology, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster LA1 4YQ, UK
| | - Gillian Dunphy
- Division of Cell Signalling and Immunology, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster LA1 4YQ, UK
| | - Ismar R. Haga
- The Pirbright Institute, Pirbright, Surrey GU24 0NF, UK
| | - Rangeetha J. Naik
- Division of Cell Signalling and Immunology, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Abdelmadjid Atrih
- Fingerprints Proteomics Facility, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Dympna J. Connolly
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland
| | - Jordan Taylor
- Division of Cell Signalling and Immunology, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Ian R. Kelsall
- Division of Cell Signalling and Immunology, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Andrew G. Bowie
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland
| | - Philippa M. Beard
- The Pirbright Institute, Pirbright, Surrey GU24 0NF, UK
- The Roslin Institute and The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh EH25 9RG, UK
| | - Leonie Unterholzner
- Division of Cell Signalling and Immunology, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster LA1 4YQ, UK
| |
Collapse
|
117
|
IFI16 is required for DNA sensing in human macrophages by promoting production and function of cGAMP. Nat Commun 2017; 8:14391. [PMID: 28186168 PMCID: PMC5309897 DOI: 10.1038/ncomms14391] [Citation(s) in RCA: 210] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 12/22/2016] [Indexed: 12/21/2022] Open
Abstract
Innate immune activation by macrophages is an essential part of host defence against infection. Cytosolic recognition of microbial DNA in macrophages leads to induction of interferons and cytokines through activation of cyclic GMP-AMP synthase (cGAS) and stimulator of interferon genes (STING). Other host factors, including interferon-gamma inducible factor 16 (IFI16), have been proposed to contribute to immune activation by DNA. However, their relation to the cGAS-STING pathway is not clear. Here, we show that IFI16 functions in the cGAS-STING pathway on two distinct levels. Depletion of IFI16 in macrophages impairs cGAMP production on DNA stimulation, whereas overexpression of IFI16 amplifies the function of cGAS. Furthermore, IFI16 is vital for the downstream signalling stimulated by cGAMP, facilitating recruitment and activation of TANK-binding kinase 1 in STING complex. Collectively, our results suggest that IFI16 is essential for efficient sensing and signalling upon DNA challenge in macrophages to promote interferons and antiviral responses. The role of IFI16 as a DNA sensor is highly controversial. With support from a Nature Communications back-to-back publication from Almine et al. the authors here provide functional evidence that IFI16 is required for DNA sensing via the cGAS-STING pathway in human macrophages.
Collapse
|
118
|
Kovarik P, Castiglia V, Ivin M, Ebner F. Type I Interferons in Bacterial Infections: A Balancing Act. Front Immunol 2016; 7:652. [PMID: 28082986 PMCID: PMC5183637 DOI: 10.3389/fimmu.2016.00652] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 12/14/2016] [Indexed: 01/21/2023] Open
Abstract
Defense against bacterial infections requires activation of the immune response as well as timely reestablishment of tissue and immune homeostasis. Instauration of homeostasis is critical for tissue regeneration, wound healing, and host recovery. Recent studies revealed that severe infectious diseases frequently result from failures in homeostatic processes rather than from inefficient pathogen eradication. Type I interferons (IFN) appear to play a key role in such processes. Remarkably, the involvement of type I IFNs in the regulation of immune and tissue homeostasis upon bacterial insult may have beneficial or detrimental consequences for the host. The reasons for such ambivalent function of type I IFNs are not understood. The disparate effects of type I IFNs on bacterial infections are in marked contrast to their well-established protective roles in most viral infections. In this review, we will focus on type I IFN effector mechanisms which balance processes involved in immune and tissue homeostasis during specific bacterial infections and highlight the most important missing links in our understanding of type I IFN functions.
Collapse
Affiliation(s)
- Pavel Kovarik
- Max F. Perutz Laboratories, University of Vienna, Vienna, Austria
| | | | - Masa Ivin
- Max F. Perutz Laboratories, University of Vienna, Vienna, Austria
| | - Florian Ebner
- Max F. Perutz Laboratories, University of Vienna, Vienna, Austria
| |
Collapse
|
119
|
Gasteiger G, D'Osualdo A, Schubert DA, Weber A, Bruscia EM, Hartl D. Cellular Innate Immunity: An Old Game with New Players. J Innate Immun 2016; 9:111-125. [PMID: 28006777 DOI: 10.1159/000453397] [Citation(s) in RCA: 118] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 11/14/2016] [Indexed: 12/29/2022] Open
Abstract
Innate immunity is a rapidly evolving field with novel cell types and molecular pathways being discovered and paradigms changing continuously. Innate and adaptive immune responses are traditionally viewed as separate from each other, but emerging evidence suggests that they overlap and mutually interact. Recently discovered cell types, particularly innate lymphoid cells and myeloid-derived suppressor cells, are gaining increasing attention. Here, we summarize and highlight current concepts in the field, focusing on innate immune cells as well as the inflammasome and DNA sensing which appear to be critical for the activation and orchestration of innate immunity, and may provide novel therapeutic opportunities for treating autoimmune, autoinflammatory, and infectious diseases.
Collapse
Affiliation(s)
- Georg Gasteiger
- Institute of Medical Microbiology and Hygiene, University of Freiburg, Freiburg Medical Center, Freiburg, Germany
| | | | | | | | | | | |
Collapse
|
120
|
Abstract
The female reproductive tract (FRT) is a major site for human immunodeficiency virus (HIV) infection. There currently exists a poor understanding of how the innate immune system is activated upon HIV transmission and how this activation may affect systemic spread of HIV from the FRT. However, multiple mechanisms for how HIV is sensed have been deciphered using model systems with cell lines and peripheral blood-derived cells. The aim of this review is to summarize recent progress in the field of HIV innate immune sensing and place this in the context of the FRT. Because HIV is somewhat unique as an STD that thrives under inflammatory conditions, the response of cells upon sensing HIV gene products can either promote or limit HIV infection depending on the context. Future studies should include investigations into how FRT-derived primary cells sense and respond to HIV to confirm conclusions drawn from non-mucosal cells. Understanding how cells of the FRT participate in and effect innate immune sensing of HIV will provide a clearer picture of what parameters during the early stages of HIV exposure determine transmission success. Such knowledge could pave the way for novel approaches for preventing HIV acquisition in women.
Collapse
|
121
|
Napier BA, Brubaker SW, Sweeney TE, Monette P, Rothmeier GH, Gertsvolf NA, Puschnik A, Carette JE, Khatri P, Monack DM. Complement pathway amplifies caspase-11-dependent cell death and endotoxin-induced sepsis severity. J Exp Med 2016; 213:2365-2382. [PMID: 27697835 PMCID: PMC5068231 DOI: 10.1084/jem.20160027] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 08/25/2016] [Indexed: 01/18/2023] Open
Abstract
Cell death and release of proinflammatory mediators contribute to mortality during sepsis. Specifically, caspase-11-dependent cell death contributes to pathology and decreases in survival time in sepsis models. Priming of the host cell, through TLR4 and interferon receptors, induces caspase-11 expression, and cytosolic LPS directly stimulates caspase-11 activation, promoting the release of proinflammatory cytokines through pyroptosis and caspase-1 activation. Using a CRISPR-Cas9-mediated genome-wide screen, we identified novel mediators of caspase-11-dependent cell death. We found a complement-related peptidase, carboxypeptidase B1 (Cpb1), to be required for caspase-11 gene expression and subsequent caspase-11-dependent cell death. Cpb1 modifies a cleavage product of C3, which binds to and activates C3aR, and then modulates innate immune signaling. We find the Cpb1-C3-C3aR pathway induces caspase-11 expression through amplification of MAPK activity downstream of TLR4 and Ifnar activation, and mediates severity of LPS-induced sepsis (endotoxemia) and disease outcome in mice. We show C3aR is required for up-regulation of caspase-11 orthologues, caspase-4 and -5, in primary human macrophages during inflammation and that c3aR1 and caspase-5 transcripts are highly expressed in patients with severe sepsis; thus, suggesting that these pathways are important in human sepsis. Our results highlight a novel role for complement and the Cpb1-C3-C3aR pathway in proinflammatory signaling, caspase-11 cell death, and sepsis severity.
Collapse
Affiliation(s)
- Brooke A Napier
- Department of Microbiology and Immunology, Stanford University, Stanford, CA 94305
| | - Sky W Brubaker
- Department of Microbiology and Immunology, Stanford University, Stanford, CA 94305
| | - Timothy E Sweeney
- Division of Biomedical Informatics Research, Stanford University School of Medicine, Stanford University, Stanford, CA 94305
- Institute for Immunity, Transplantation, and Infection, Stanford University, Stanford, CA 94305
| | - Patrick Monette
- Department of Biology, Middlebury College, Middlebury, VT 05753
| | | | - Nina A Gertsvolf
- Department of Microbiology and Immunology, Stanford University, Stanford, CA 94305
| | - Andreas Puschnik
- Department of Microbiology and Immunology, Stanford University, Stanford, CA 94305
| | - Jan E Carette
- Department of Microbiology and Immunology, Stanford University, Stanford, CA 94305
| | - Purvesh Khatri
- Division of Biomedical Informatics Research, Stanford University School of Medicine, Stanford University, Stanford, CA 94305
- Institute for Immunity, Transplantation, and Infection, Stanford University, Stanford, CA 94305
| | - Denise M Monack
- Department of Microbiology and Immunology, Stanford University, Stanford, CA 94305
| |
Collapse
|
122
|
Tao J, Zhou X, Jiang Z. cGAS-cGAMP-STING: The three musketeers of cytosolic DNA sensing and signaling. IUBMB Life 2016; 68:858-870. [PMID: 27706894 DOI: 10.1002/iub.1566] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2016] [Accepted: 09/11/2016] [Indexed: 12/19/2022]
Abstract
Innate immunity is the first line of host defense against invading pathogens. The detection of aberrant nucleic acids which represent some conserved PAMPs triggers robust type I IFN-mediated innate immune responses. Host- or pathogen-derived cytosolic DNA binds and activates the DNA sensor cGAS, which synthesizes the second messenger 2'3'-cGAMP and triggers STING-dependent downstream signaling. Here, we highlight recent progress in cGAS-cGAMP-STING, the Three Musketeers of cytosolic DNA sensing and signaling, and their essential roles in infection, autoimmune diseases, and cancer. We also focus on the regulation of these critical signal components by variant host/pathogen proteins and update our understanding of this indispensable pathway to provide new insights for drug discovery. © 2016 IUBMB Life, 68(11):858-870, 2016.
Collapse
Affiliation(s)
- Jianli Tao
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China.,Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking University, Beijing, China.,Peking-Tsinghua Center for Life Sciences, Beijing, China
| | - Xiang Zhou
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China.,Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking University, Beijing, China.,Peking-Tsinghua Center for Life Sciences, Beijing, China
| | - Zhengfan Jiang
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China. .,Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking University, Beijing, China. .,Peking-Tsinghua Center for Life Sciences, Beijing, China.
| |
Collapse
|
123
|
Man SM, Karki R, Sasai M, Place DE, Kesavardhana S, Temirov J, Frase S, Zhu Q, Malireddi RKS, Kuriakose T, Peters JL, Neale G, Brown SA, Yamamoto M, Kanneganti TD. IRGB10 Liberates Bacterial Ligands for Sensing by the AIM2 and Caspase-11-NLRP3 Inflammasomes. Cell 2016; 167:382-396.e17. [PMID: 27693356 DOI: 10.1016/j.cell.2016.09.012] [Citation(s) in RCA: 217] [Impact Index Per Article: 27.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 07/16/2016] [Accepted: 09/06/2016] [Indexed: 02/08/2023]
Abstract
The inflammasome is an intracellular signaling complex, which on recognition of pathogens and physiological aberration, drives activation of caspase-1, pyroptosis, and the release of the pro-inflammatory cytokines IL-1β and IL-18. Bacterial ligands must secure entry into the cytoplasm to activate inflammasomes; however, the mechanisms by which concealed ligands are liberated in the cytoplasm have remained unclear. Here, we showed that the interferon-inducible protein IRGB10 is essential for activation of the DNA-sensing AIM2 inflammasome by Francisella novicida and contributed to the activation of the LPS-sensing caspase-11 and NLRP3 inflammasome by Gram-negative bacteria. IRGB10 directly targeted cytoplasmic bacteria through a mechanism requiring guanylate-binding proteins. Localization of IRGB10 to the bacterial cell membrane compromised bacterial structural integrity and mediated cytosolic release of ligands for recognition by inflammasome sensors. Overall, our results reveal IRGB10 as part of a conserved signaling hub at the interface between cell-autonomous immunity and innate immune sensing pathways.
Collapse
Affiliation(s)
- Si Ming Man
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Rajendra Karki
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Miwa Sasai
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Laboratory of Immunoparasitology, World Premier International Immunology Frontier Research Center, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - David E Place
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Sannula Kesavardhana
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Jamshid Temirov
- Department of Cellular Imaging Shared Resource, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Sharon Frase
- Cell and Tissue Imaging Center, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Qifan Zhu
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA; Integrated Biomedical Sciences Program, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | | | - Teneema Kuriakose
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Jennifer L Peters
- Department of Cellular Imaging Shared Resource, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Geoffrey Neale
- Hartwell Center for Bioinformatics & Biotechnology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Scott A Brown
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Masahiro Yamamoto
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Laboratory of Immunoparasitology, World Premier International Immunology Frontier Research Center, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | | |
Collapse
|
124
|
Chen M, Meng Q, Qin Y, Liang P, Tan P, He L, Zhou Y, Chen Y, Huang J, Wang RF, Cui J. TRIM14 Inhibits cGAS Degradation Mediated by Selective Autophagy Receptor p62 to Promote Innate Immune Responses. Mol Cell 2016; 64:105-119. [PMID: 27666593 DOI: 10.1016/j.molcel.2016.08.025] [Citation(s) in RCA: 249] [Impact Index Per Article: 31.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 07/08/2016] [Accepted: 08/18/2016] [Indexed: 12/20/2022]
Abstract
Cyclic GMP-AMP synthase (cGAS) is an essential DNA virus sensor that triggers type I interferon (IFN) signaling by producing cGAMP to initiate antiviral immunity. However, post-translational regulation of cGAS remains largely unknown. We report that K48-linked ubiquitination of cGAS is a recognition signal for p62-depdendent selective autophagic degradation. The induction of TRIM14 by type I IFN accelerates cGAS stabilization by recruiting USP14 to cleave the ubiquitin chains of cGAS at lysine (K) 414. Knockout of TRIM14 impairs herpes simplex virus type 1 (HSV-1)-triggered antiviral responses in a cGAS-dependent manner. Due to impaired type I IFN production, Trim14-/- mice are highly susceptible to lethal HSV-1 infection. Taken together, our findings reveal a positive feedback loop of cGAS signaling generated by TRIM14-USP14 and provide insights into the crosstalk between autophagy and type I IFN signaling in innate immunity.
Collapse
Affiliation(s)
- Meixin Chen
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, PRC
| | - Qingcai Meng
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, PRC
| | - Yunfei Qin
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, PRC; School of Life Sciences, Zhengzhou University, Zhengzhou 450001, Henan, PRC
| | - Puping Liang
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, PRC
| | - Peng Tan
- Center for Inflammation and Epigenetics, Houston Methodist Research Institute, Houston, TX 77030, USA; Institute of Biosciences and Technology, Texas A&M University, Health Science Center, Houston, TX 77030, USA
| | - Lian He
- Institute of Biosciences and Technology, Texas A&M University, Health Science Center, Houston, TX 77030, USA
| | - Yubin Zhou
- Institute of Biosciences and Technology, Texas A&M University, Health Science Center, Houston, TX 77030, USA
| | - Yongjun Chen
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, PRC
| | - Junjiu Huang
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, PRC; State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510275, PRC.
| | - Rong-Fu Wang
- Center for Inflammation and Epigenetics, Houston Methodist Research Institute, Houston, TX 77030, USA; Institute of Biosciences and Technology, Texas A&M University, Health Science Center, Houston, TX 77030, USA; Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, New York, NY, USA.
| | - Jun Cui
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, PRC; Collaborative Innovation Center of Cancer Medicine, Sun Yat-sen University, Guangzhou 510275, PRC.
| |
Collapse
|
125
|
Gray EE, Winship D, Snyder JM, Child SJ, Geballe AP, Stetson DB. The AIM2-like Receptors Are Dispensable for the Interferon Response to Intracellular DNA. Immunity 2016; 45:255-66. [PMID: 27496731 DOI: 10.1016/j.immuni.2016.06.015] [Citation(s) in RCA: 147] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Revised: 04/22/2016] [Accepted: 05/05/2016] [Indexed: 11/27/2022]
Abstract
Detection of intracellular DNA triggers activation of the STING-dependent interferon-stimulatory DNA (ISD) pathway, which is essential for antiviral responses. Multiple DNA sensors have been proposed to activate this pathway, including AIM2-like receptors (ALRs). Whether the ALRs are essential for activation of this pathway remains unknown. To rigorously explore the function of ALRs, we generated mice lacking all 13 ALR genes. We found that ALRs are dispensable for the type I interferon (IFN) response to transfected DNA ligands, DNA virus infection, and lentivirus infection. We also found that ALRs do not contribute to autoimmune disease in the Trex1(-/-) mouse model of Aicardi-Goutières Syndrome. Finally, CRISPR-mediated disruption of the human AIM2-like receptor IFI16 in primary fibroblasts revealed that IFI16 is not essential for the IFN response to human cytomegalovirus infection. Our findings indicate that ALRs are dispensable for the ISD response and suggest that alternative functions for these receptors should be explored.
Collapse
Affiliation(s)
- Elizabeth E Gray
- Department of Immunology, University of Washington School of Medicine, Seattle, WA, 98195, USA
| | - Damion Winship
- Department of Immunology, University of Washington School of Medicine, Seattle, WA, 98195, USA
| | - Jessica M Snyder
- Department of Comparative Medicine, University of Washington School of Medicine, Seattle, WA, 98195, USA
| | - Stephanie J Child
- Departments of Microbiology and Medicine, University of Washington School of Medicine, Seattle, WA, 98195, USA; Divisions of Human Biology and Clinical Research, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Adam P Geballe
- Departments of Microbiology and Medicine, University of Washington School of Medicine, Seattle, WA, 98195, USA; Divisions of Human Biology and Clinical Research, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Daniel B Stetson
- Department of Immunology, University of Washington School of Medicine, Seattle, WA, 98195, USA.
| |
Collapse
|
126
|
Liu X, Jiao Y, Cao Y, Deng N, Ma Y, Hasty KA, Kang A, Chen H, Stuart JM, Gu W. Decreased expression levels of Ifi genes is associated to the increased resistance to spontaneous arthritis disease in mice deficiency of IL-1RA. BMC Immunol 2016; 17:25. [PMID: 27480124 PMCID: PMC4970213 DOI: 10.1186/s12865-016-0163-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 07/12/2016] [Indexed: 01/21/2023] Open
Abstract
Background The mouse strain BALB/c deficient in IL-1 receptor antagonist protein (Il-1ra) develops spontaneous arthritis disease (SAD) while the strain DBA/1 IL1rn-/- with the same deficiency does not. Previously, we mapped a QTL on chromosome 1 for SAD and then developed a congenic mouse strain BALB.D1-1-/- that contains the QTL genomic fragment associated with resistance from DBA/1-/- on a BALB/c-/- background. The congenic strain was relatively resistant to spontaneous arthritis and had delayed onset and reduced severity of disease. We obtained whole genome expression profiles from the spleen of the congenic strain BALB.D1-1-/- and four other strains, the wild type BALB/c, DBA/1 and the deficient DBA/1 IL1rn-/- and the BALB/c IL1rn-/-. We then compared the similarities and differences between the congenic strain and the four parental strains. Here we report the selected potential causal genes based on differential expression levels as well as function of genes. Results There is a considerable number of genes that are differentially expressed between the congenic strain and the three parental strains, BALB/c, DBA/1, and DBA/1-/-. However there only a few differentially expressed genes were identified by comparing the congenic strain and the BALB/c-/-strain. These differentially expressed genes are mainly from T-cell receptor beta chain (Tcrb) and interferon-activatable protein (Ifi) genes. These genes are also differentially expressed between congenic strain and BALB/c strains. However, their expression levels in the congenic strain are similar to that in DBA/1 and DBA/1-/-. The expression level of Tcrb-j gene is positively associated with two genes of Ifi gene 200 cluster. Conclusions Decreased expression levels of Ifi genes is associated to the increased resistance to spontaneous arthritis disease and with down regulation of expressions of Tcrb genes in the mouse congenic strain. Ifi genes may play an important role in the susceptibility to SAD in mice. Electronic supplementary material The online version of this article (doi:10.1186/s12865-016-0163-y) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Xiaoyun Liu
- Mudanjiang Medical College, Mudanjiang, HeilongJiang, 157001, People's Republic of China.,Department of Orthopaedic Surgery and Biomedical Engineering, University of Tennessee Health Science Center (UTHSC), Memphis, TN, 38163, USA
| | - Yan Jiao
- Mudanjiang Medical College, Mudanjiang, HeilongJiang, 157001, People's Republic of China. .,Department of Orthopaedic Surgery and Biomedical Engineering, University of Tennessee Health Science Center (UTHSC), Memphis, TN, 38163, USA.
| | - Yanhong Cao
- Department of Orthopaedic Surgery and Biomedical Engineering, University of Tennessee Health Science Center (UTHSC), Memphis, TN, 38163, USA.,Institute of Kaschin-beck Disease, Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, 150081, China.,Key Laboratory of Etiologic Epidemiology, Education Bureau of Heilongjiang Province & Ministry of Health (23618104), Harbin, 150081, China
| | - Nan Deng
- Department of Medicine, University of Tennessee Health Science Center, Memphis, TN, 38163, USA
| | - Yonghui Ma
- Department of Orthopaedic Surgery and Biomedical Engineering, University of Tennessee Health Science Center (UTHSC), Memphis, TN, 38163, USA
| | - Karen A Hasty
- Department of Orthopaedic Surgery and Biomedical Engineering, University of Tennessee Health Science Center (UTHSC), Memphis, TN, 38163, USA.,Research Service, Veterans Affairs Medical Center, 1030 Jefferson Avenue, Memphis, TN, 38104, USA
| | - Andrew Kang
- Department of Medicine, University of Tennessee Health Science Center, Memphis, TN, 38163, USA
| | - Hong Chen
- Center of integrative research, The first Hospital of Qiqihaer City, 30 Gongyuan Road, Longsha District, Qiqihaer, Heilongjiang, 161005, People's Republic of China
| | - John M Stuart
- Department of Medicine, University of Tennessee Health Science Center, Memphis, TN, 38163, USA.,Research Service, Veterans Affairs Medical Center, 1030 Jefferson Avenue, Memphis, TN, 38104, USA
| | - Weikuan Gu
- Department of Orthopaedic Surgery and Biomedical Engineering, University of Tennessee Health Science Center (UTHSC), Memphis, TN, 38163, USA. .,Research Service, Veterans Affairs Medical Center, 1030 Jefferson Avenue, Memphis, TN, 38104, USA.
| |
Collapse
|
127
|
For Better or Worse: Cytosolic DNA Sensing during Intracellular Bacterial Infection Induces Potent Innate Immune Responses. J Mol Biol 2016; 428:3372-86. [DOI: 10.1016/j.jmb.2016.04.030] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 04/19/2016] [Accepted: 04/21/2016] [Indexed: 01/09/2023]
|
128
|
Yang J, Liu Z, Xiao TS. Post-translational regulation of inflammasomes. Cell Mol Immunol 2016; 14:65-79. [PMID: 27345727 PMCID: PMC5214939 DOI: 10.1038/cmi.2016.29] [Citation(s) in RCA: 138] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Revised: 05/05/2016] [Accepted: 05/05/2016] [Indexed: 12/16/2022] Open
Abstract
Inflammasomes play essential roles in immune protection against microbial infections. However, excessive inflammation is implicated in various human diseases, including autoinflammatory syndromes, diabetes, multiple sclerosis, cardiovascular disorders and neurodegenerative diseases. Therefore, precise regulation of inflammasome activities is critical for adequate immune protection while limiting collateral tissue damage. In this review, we focus on the emerging roles of post-translational modifications (PTMs) that regulate activation of the NLRP3, NLRP1, NLRC4, AIM2 and IFI16 inflammasomes. We anticipate that these types of PTMs will be identified in other types of and less well-characterized inflammasomes. Because these highly diverse and versatile PTMs shape distinct inflammatory responses in response to infections and tissue damage, targeting the enzymes involved in these PTMs will undoubtedly offer opportunities for precise modulation of inflammasome activities under various pathophysiological conditions.
Collapse
Affiliation(s)
- Jie Yang
- Department of Pathology, Case Western Reserve University, Cleveland, OH 44106-7288, USA.,Graduate Program in Physiology and Biophysics, Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH 44106-7288, USA
| | - Zhonghua Liu
- Department of Pathology, Case Western Reserve University, Cleveland, OH 44106-7288, USA
| | - Tsan Sam Xiao
- Department of Pathology, Case Western Reserve University, Cleveland, OH 44106-7288, USA
| |
Collapse
|
129
|
Andrade WA, Agarwal S, Mo S, Shaffer SA, Dillard JP, Schmidt T, Hornung V, Fitzgerald KA, Kurt-Jones EA, Golenbock DT. Type I Interferon Induction by Neisseria gonorrhoeae: Dual Requirement of Cyclic GMP-AMP Synthase and Toll-like Receptor 4. Cell Rep 2016; 15:2438-48. [PMID: 27264171 PMCID: PMC5401638 DOI: 10.1016/j.celrep.2016.05.030] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 03/28/2016] [Accepted: 05/05/2016] [Indexed: 12/29/2022] Open
Abstract
The innate immune system is the first line of defense against Neisseria gonorrhoeae (GC). Exposure of cells to GC lipooligosaccharides induces a strong immune response, leading to type I interferon (IFN) production via TLR4/MD-2. In addition to living freely in the extracellular space, GC can invade the cytoplasm to evade detection and elimination. Double-stranded DNA introduced into the cytosol binds and activates the enzyme cyclic-GMP-AMP synthase (cGAS), which produces 2'3'-cGAMP and triggers STING/TBK-1/IRF3 activation, resulting in type I IFN expression. Here, we reveal a cytosolic response to GC DNA that also contributes to type I IFN induction. We demonstrate that complete IFN-β induction by live GC depends on both cGAS and TLR4. Type I IFN is detrimental to the host, and dysregulation of iron homeostasis genes may explain lower bacteria survival in cGAS(-/-) and TLR4(-/-) cells. Collectively, these observations reveal cooperation between TLRs and cGAS in immunity to GC infection.
Collapse
Affiliation(s)
- Warrison A Andrade
- Division of Infectious Diseases, University of Massachusetts Medical School, Worcester, MA 01605, USA; Program in Innate Immunity, Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Sarika Agarwal
- Division of Infectious Diseases, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Shunyan Mo
- Proteomics and Mass Spectrometry Facility, University of Massachusetts Medical School, Worcester, MA 01605, USA; Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Scott A Shaffer
- Proteomics and Mass Spectrometry Facility, University of Massachusetts Medical School, Worcester, MA 01605, USA; Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Joseph P Dillard
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Tobias Schmidt
- Institute of Molecular Medicine, Universitätsklinikum Bonn, Bonn 53127, Germany
| | - Veit Hornung
- Institute of Molecular Medicine, Universitätsklinikum Bonn, Bonn 53127, Germany
| | - Katherine A Fitzgerald
- Division of Infectious Diseases, University of Massachusetts Medical School, Worcester, MA 01605, USA; Program in Innate Immunity, Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA; Centre of Molecular Inflammation Research and Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, 7489 Trondheim, Norway
| | - Evelyn A Kurt-Jones
- Division of Infectious Diseases, University of Massachusetts Medical School, Worcester, MA 01605, USA; Program in Innate Immunity, Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Douglas T Golenbock
- Division of Infectious Diseases, University of Massachusetts Medical School, Worcester, MA 01605, USA; Program in Innate Immunity, Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA; Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, MG 30190-002, Brazil.
| |
Collapse
|
130
|
Abstract
Inflammasomes are multiprotein signalling platforms that control the inflammatory response and coordinate antimicrobial host defences. They are assembled by pattern-recognition receptors following the detection of pathogenic microorganisms and danger signals in the cytosol of host cells, and they activate inflammatory caspases to produce cytokines and to induce pyroptotic cell death. The clinical importance of inflammasomes reaches beyond infectious disease, as dysregulated inflammasome activity is associated with numerous hereditary and acquired inflammatory disorders. In this Review, we discuss the recent developments in inflammasome research with a focus on the molecular mechanisms that govern inflammasome assembly, signalling and regulation.
Collapse
Affiliation(s)
- Petr Broz
- Focal Area Infection Biology, Biozentrum, University of Basel, CH-4056 Basel, Switzerland
| | - Vishva M Dixit
- Genentech Inc., South San Francisco, California 94080, USA
| |
Collapse
|
131
|
Abstract
Type I interferons (IFNs) are pleiotropic cytokines well recognized for their role in the induction of a potent antiviral gene program essential for host defense against viruses. They also modulate innate and adaptive immune responses. However, the role of type I IFNs in host defense against bacterial infections is enigmatic. Depending on the bacterium, they exert seemingly opposite and capricious functions. In this review, we summarize the effect of type I IFNs on specific bacterial infections and highlight the effector mechanisms regulated by type I IFNs in an attempt to elucidate new avenues to understanding their role.
Collapse
Affiliation(s)
- Gayle M Boxx
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Genhong Cheng
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA.
| |
Collapse
|
132
|
Vitak N, Hume DA, Chappell KJ, Sester DP, Stacey KJ. Induction of interferon and cell death in response to cytosolic DNA in chicken macrophages. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2016; 59:145-152. [PMID: 26828392 DOI: 10.1016/j.dci.2016.01.023] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Revised: 01/28/2016] [Accepted: 01/28/2016] [Indexed: 06/05/2023]
Abstract
Responses to cytosolic DNA can protect against both infectious organisms and the mutagenic effect of DNA integration. Recognition of invading DNA is likely to be fundamental to eukaryotic cellular life, but has been described only in mammals. Introduction of DNA into chicken macrophages induced type I interferon mRNA via a pathway conserved with mammals, requiring the receptor cGAS and the signalling protein STING. A second pathway of cytosolic DNA recognition in mammalian macrophages, initiated by absent in melanoma 2 (AIM2), results in rapid inflammasome-mediated pyroptotic cell death. AIM2 is restricted to mammals. Nevertheless, chicken macrophages underwent lytic cell death within 15 min of DNA transfection. The mouse AIM2-mediated response requires double stranded DNA, but chicken cell death was maintained with denatured DNA. This appears to be a novel form of rapid necrotic cell death, which we propose is an ancient response rendered redundant in mammalian macrophages by the appearance of the AIM2 inflammasome. The retention of these cytosolic DNA responses through evolution, with both conserved and non-conserved mechanisms, suggests a fundamental importance in cellular defence.
Collapse
Affiliation(s)
- Nazarii Vitak
- School of Chemistry and Molecular Biosciences and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Qld 4072, Australia
| | - David A Hume
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, The University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK
| | - Keith J Chappell
- School of Chemistry and Molecular Biosciences and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Qld 4072, Australia
| | - David P Sester
- School of Chemistry and Molecular Biosciences and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Qld 4072, Australia.
| | - Katryn J Stacey
- School of Chemistry and Molecular Biosciences and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Qld 4072, Australia.
| |
Collapse
|
133
|
Richard K, Vogel SN, Perkins DJ. Type I interferon licenses enhanced innate recognition and transcriptional responses to Franciscella tularensis live vaccine strain. Innate Immun 2016; 22:363-72. [PMID: 27231145 DOI: 10.1177/1753425916650027] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 04/22/2016] [Indexed: 12/13/2022] Open
Abstract
The innate inflammatory response to Francisella tularensis (Ft) in macrophages is significantly governed by the expression of type I interferon (IFN). Previously, the proteolytic processing and maturation of pro-IL-1β protein was shown to depend upon type I IFN expression. We show in this report that paracrine type I IFN can profoundly enhance innate recognition and TLR-dependent transcriptional responses to Ft infection upstream of its role in inflammasome regulation in both primary human monocyte-derived macrophages and primary murine peritoneal macrophages but not murine bone marrow-derived macrophages. This type I IFN-enhanced response is synergistic with TLR2 transcriptional responses, partially TLR2-independent, but strictly MyD88-dependent.
Collapse
Affiliation(s)
- Katharina Richard
- Department of Microbiology and Immunology, University of Maryland, Baltimore (UMB), School of Medicine, Baltimore, MD, USA
| | - Stefanie N Vogel
- Department of Microbiology and Immunology, University of Maryland, Baltimore (UMB), School of Medicine, Baltimore, MD, USA
| | - Darren J Perkins
- Department of Microbiology and Immunology, University of Maryland, Baltimore (UMB), School of Medicine, Baltimore, MD, USA
| |
Collapse
|
134
|
The role of cGAS in innate immunity and beyond. J Mol Med (Berl) 2016; 94:1085-1093. [DOI: 10.1007/s00109-016-1423-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 04/04/2016] [Accepted: 04/08/2016] [Indexed: 12/19/2022]
|
135
|
Man SM, Karki R, Kanneganti TD. DNA-sensing inflammasomes: regulation of bacterial host defense and the gut microbiota. Pathog Dis 2016; 74:ftw028. [PMID: 27056948 DOI: 10.1093/femspd/ftw028] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/01/2016] [Indexed: 02/07/2023] Open
Abstract
DNA sensors are formidable immune guardians of the host. At least 14 cytoplasmic DNA sensors have been identified in recent years, each with specialized roles in driving inflammation and/or cell death. Of these, AIM2 is a sensor of dsDNA, and forms an inflammasome complex to activate the cysteine protease caspase-1, mediates the release of the proinflammatory cytokines IL-1β and IL-18, and induces pyroptosis. The inflammasome sensor NLRP3 can also respond to DNA in the forms of oxidized mitochondrial DNA and the DNA derivative RNA:DNA hybrids produced by bacteria, whereas the putative inflammasome sensor IFI16 responds to viral DNA in the nucleus. Although inflammasomes provoke inflammation for anti-microbial host defense, they must also maintain homeostasis with commensal microbiota. Here, we outline recent advances highlighting the complex relationship between DNA-sensing inflammasomes, bacterial host defense and the gut microbiota.
Collapse
Affiliation(s)
- Si Ming Man
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105-3678, USA
| | - Rajendra Karki
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105-3678, USA
| | | |
Collapse
|
136
|
Abstract
Stimulator of interferon genes (STING) is activated by binding to cyclic dinucleotides (CDNs), which results in potent cytokine production. CDNs are produced by certain intracellular bacteria and are generated by the cyclic GMP–AMP synthase (cGAS) following binding to cytosolic DNA species, such as viral DNA. STING-inducible innate immune molecules are essential for protection of the host against pathogens and are important for the stimulation of adaptive immunity. Self-DNA, for example from the nucleus or mitochondria, can leak into the cytosolic compartment and stimulate STING activity to cause autoinflammatory disease. Certain mutations in the gene encoding STING can cause the protein to become permanently active and similarly induce autoinflammatory responses. STING can be activated in phagocytes by DNA released from engulfed tumour cells and drive the production of cytokines necessary for generating robust antitumour T cell responses. DNA-damaging agents can cause the release of nuclear DNA into the cytosol that stimulates STING-dependent cytokine production and phagocyte infiltration. This may be essential for eliminating damaged cells and generating antitumour T cell responses, but chronic stimulation may also promote inflammation-aggravated cancer. STING agonists exert potent antitumour activity and may be effective, novel adjuvants in vaccine formulations. In contrast, inhibitors of STING signalling may be beneficial for the treatment of autoinflammatory disease, such as systemic lupus erythematosus (SLE), Aicardi–Goutières syndrome (AGS) and STING-associated vasculopathy with onset in infancy (SAVI).
Activation of STING (stimulator of interferon genes) by cytosolic aberrant DNA species or cyclic dinucleotides triggers transcription of numerous innate immune genes. In this Review, the author summarizes recent insights into the regulation of STING signalling and its role in autoinflammatory disease and cancer. The rapid detection of microbial agents is essential for the effective initiation of host defence mechanisms against infection. Understanding how cells detect cytosolic DNA to trigger innate immune gene transcription has important implications — not only for comprehending the immune response to pathogens but also for elucidating the causes of autoinflammatory disease involving the sensing of self-DNA and the generation of effective antitumour adaptive immunity. The discovery of the STING (stimulator of interferon genes)-controlled innate immune pathway, which mediates cytosolic DNA-induced signalling events, has recently provided important insights into these processes, opening the way for the development of novel immunization regimes, as well as therapies to treat autoinflammatory disease and cancer.
Collapse
Affiliation(s)
- Glen N Barber
- Department of Cell Biology and Sylvester Comprehensive Cancer Center, University of Miami School of Medicine, Miami, Florida 33136, USA
| |
Collapse
|
137
|
Abstract
UNLABELLED Differences among individuals in susceptibility to infectious diseases can be modulated by host genetics. Much of the research in this field has aimed to identify loci within the host genome that are associated with these differences. In mice, A/J (AJ) and C57BL/6J (B6) mice show differential susceptibilities to various pathogens, including the intracellular pathogen Francisella tularensis. Because macrophages are the main initial target during F. tularensis infection, we explored early interactions of macrophages from these two mouse strains with F. tularensis as well as the genetic factors underlying these interactions. Our results indicate that bacterial interactions with bone marrow-derived macrophages (BMDMs) during early stages of infection are different in the AJ and B6 strains. During these early stages, bacteria are more numerous in B6 than in AJ macrophages and display differences in trafficking and early transcriptional response within these macrophages. To determine the genetic basis for these differences, we infected BMDMs isolated from recombinant inbred (RI) mice derived from reciprocal crosses between AJ and B6, and we followed early bacterial counts within these macrophages. Quantitative trait locus (QTL) analysis revealed a locus on chromosome 19 that is associated with early differences in bacterial counts in AJ versus B6 macrophages. QTL analysis of published data that measured the differential susceptibilities of the same RI mice to an in vivo challenge with F. tularensis confirmed the F. tularensis susceptibility QTL on chromosome 19. Overall, our results show that early interactions of macrophages with F. tularensis are dependent on the macrophage genetic background. IMPORTANCE Francisella tularensis is a highly pathogenic bacterium with a very low infectious dose in humans. Some mechanisms of bacterial virulence have been elucidated, but the host genetic factors that contribute to host resistance or susceptibility are largely unknown. In this work, we have undertaken a genetic approach to assess what these factors are in mice. Analyzing early interactions of macrophages with the bacteria as well as data on overall susceptibility to infection revealed a locus on chromosome 19 that is associated with both phenotypes. In addition, our work revealed differences in the early macrophage response between macrophages with different genetic backgrounds. Overall, this work suggests some intriguing links between in vitro and in vivo infection models and should aid in further elucidating the genetic circuits behind the host response to Francisella tularensis infection.
Collapse
|
138
|
Unique Loss of the PYHIN Gene Family in Bats Amongst Mammals: Implications for Inflammasome Sensing. Sci Rep 2016; 6:21722. [PMID: 26906452 PMCID: PMC4764838 DOI: 10.1038/srep21722] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 01/29/2016] [Indexed: 12/19/2022] Open
Abstract
Recent genomic analysis of two bat species (Pteropus alecto and Myotis davidii) revealed the absence of the PYHIN gene family. This family is recognized as important immune sensors of intracellular self and foreign DNA and activators of the inflammasome and/or interferon pathways. Further assessment of a wider range of bat genomes was necessary to determine if this is a universal pattern for this large mammalian group. Here we expanded genomic analysis of this gene family to include ten bat species. We confirmed the complete loss of this gene family, with only a truncated AIM2 remaining in one species (Pteronotus parnellii). Divergence of the PYHIN gene loci between the bat lineages infers different loss-of-function histories during bat evolution. While all other major groups of placental mammals have at least one gene member, only bats have lost the entire family. This removal of inflammasome DNA sensors may indicate an important adaptation that is flight-induced and related, at least in part, to pathogen-host co-existence.
Collapse
|
139
|
Abstract
Francisella tularensis is a facultative intracellular bacterium causing tularemia, a zoonotic disease. Francisella replicates in the macrophage cytosol and eventually triggers cytosolic immune responses. In murine macrophages, Francisella novicida and Francisella tularensis live vaccine strain lyse in the host cytosol and activate the cytosolic DNA receptor Aim2. Here, we review the mechanisms leading or contributing to Aim2 inflammasome activation, including the role of TLRs and of IFN signaling and the implication of the guanylate-binding proteins 2 and 5 in triggering cytosolic bacteriolysis. Furthermore, we present how this cytosolic Gram-negative bacterium escapes recognition by caspase-11 but can trigger a non-canonical caspase-8 inflammasome. In addition, we highlight the differences in inflammasome activation in murine and human cells with pyrin, NLRP3, and AIM2 involved in sensing Francisella in human phagocytes. From a bacterial prospective, we describe the hiding strategy of Francisella to escape recognition by innate sensors and to resist to bacteriolysis in the host cytosol. Finally, we discuss the inability of the inflammasome sensors to detect F. tularensis subspecies tularensis strains, making them highly pathogenic stealth microbes.
Collapse
|
140
|
Man SM, Karki R, Kanneganti TD. AIM2 inflammasome in infection, cancer, and autoimmunity: Role in DNA sensing, inflammation, and innate immunity. Eur J Immunol 2015; 46:269-80. [PMID: 26626159 DOI: 10.1002/eji.201545839] [Citation(s) in RCA: 233] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 11/13/2015] [Accepted: 11/26/2015] [Indexed: 12/15/2022]
Abstract
Recognition of DNA by the cell is an important immunological signature that marks the initiation of an innate immune response. AIM2 is a cytoplasmic sensor that recognizes dsDNA of microbial or host origin. Upon binding to DNA, AIM2 assembles a multiprotein complex called the inflammasome, which drives pyroptosis and proteolytic cleavage of the proinflammatory cytokines pro-IL-1β and pro-IL-18. Release of microbial DNA into the cytoplasm during infection by Francisella, Listeria, Mycobacterium, mouse cytomegalovirus, vaccinia virus, Aspergillus, and Plasmodium species leads to activation of the AIM2 inflammasome. In contrast, inappropriate recognition of cytoplasmic self-DNA by AIM2 contributes to the development of psoriasis, dermatitis, arthritis, and other autoimmune and inflammatory diseases. Inflammasome-independent functions of AIM2 have also been described, including the regulation of the intestinal stem cell proliferation and the gut microbiota ecology in the control of colorectal cancer. In this review we provide an overview of the latest research on AIM2 inflammasome and its role in infection, cancer, and autoimmunity.
Collapse
Affiliation(s)
- Si Ming Man
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Rajendra Karki
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | | |
Collapse
|
141
|
Wu JJ, Li W, Shao Y, Avey D, Fu B, Gillen J, Hand T, Ma S, Liu X, Miley W, Konrad A, Neipel F, Stürzl M, Whitby D, Li H, Zhu F. Inhibition of cGAS DNA Sensing by a Herpesvirus Virion Protein. Cell Host Microbe 2015; 18:333-44. [PMID: 26320998 PMCID: PMC4567405 DOI: 10.1016/j.chom.2015.07.015] [Citation(s) in RCA: 209] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 06/16/2015] [Accepted: 07/30/2015] [Indexed: 12/20/2022]
Abstract
Invading viral DNA can be recognized by the host cytosolic DNA sensor, cyclic GMP-AMP (cGAMP) synthase (cGAS), resulting in production of the second messenger cGAMP, which directs the adaptor protein STING to stimulate production of type I interferons (IFNs). Although several DNA viruses are sensed by cGAS, viral strategies targeting cGAS are virtually unknown. We report here that Kaposi's sarcoma-associated herpesvirus (KSHV) ORF52, an abundant gammaherpesvirus-specific tegument protein, subverts cytosolic DNA sensing by directly inhibiting cGAS enzymatic activity through a mechanism involving both cGAS binding and DNA binding. Moreover, ORF52 homologs in other gammaherpesviruses also inhibit cGAS activity and similarly bind cGAS and DNA, suggesting conserved inhibitory mechanisms. Furthermore, KSHV infection evokes cGAS-dependent responses that can limit the infection, and an ORF52 null mutant exhibits increased cGAS signaling. Our findings reveal a mechanism through which gammaherpesviruses antagonize host cGAS DNA sensing.
Collapse
Affiliation(s)
- Jian-jun Wu
- Department of Biological Science, Florida State University, Tallahassee, FL 32306, USA
| | - Wenwei Li
- Department of Biological Science, Florida State University, Tallahassee, FL 32306, USA
| | - Yaming Shao
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, USA
| | - Denis Avey
- Department of Biological Science, Florida State University, Tallahassee, FL 32306, USA
| | - Bishi Fu
- Department of Biological Science, Florida State University, Tallahassee, FL 32306, USA
| | - Joseph Gillen
- Department of Biological Science, Florida State University, Tallahassee, FL 32306, USA
| | - Travis Hand
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, USA
| | - Siming Ma
- Department of Biological Science, Florida State University, Tallahassee, FL 32306, USA
| | - Xia Liu
- Department of Biological Science, Florida State University, Tallahassee, FL 32306, USA
| | - Wendell Miley
- Viral Oncology Section, AIDS and Cancer Virus Program, Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA
| | - Andreas Konrad
- Division of Molecular and Experimental Surgery, Department of Surgery, University Medical Center Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen 91054, Germany
| | - Frank Neipel
- Institute of Clinical and Molecular Virology, University of Erlangen-Nürnberg, Schlossgarten 4, D-91054 Erlangen, Germany
| | - Michael Stürzl
- Division of Molecular and Experimental Surgery, Department of Surgery, University Medical Center Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen 91054, Germany
| | - Denise Whitby
- Viral Oncology Section, AIDS and Cancer Virus Program, Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA
| | - Hong Li
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, USA; Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306, USA
| | - Fanxiu Zhu
- Department of Biological Science, Florida State University, Tallahassee, FL 32306, USA.
| |
Collapse
|
142
|
Wallet P, Lagrange B, Henry T. [Guanylate binding proteins: new proteins from the cell host cytosol involved in antibacterial immunity]. Med Sci (Paris) 2015; 31:600-3. [PMID: 26152160 DOI: 10.1051/medsci/20153106009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Pierre Wallet
- Centre international de recherche en infectiologie (CIRI), Inserm U1111, 21, avenue Tony Garnier, 69365 Lyon, France
| | - Brice Lagrange
- Centre international de recherche en infectiologie (CIRI), Inserm U1111, 21, avenue Tony Garnier, 69365 Lyon, France
| | - Thomas Henry
- Centre international de recherche en infectiologie (CIRI), Inserm U1111, 21, avenue Tony Garnier, 69365 Lyon, France
| |
Collapse
|
143
|
|
144
|
Innate immune recognition of DNA: A recent history. Virology 2015; 479-480:146-52. [PMID: 25816762 DOI: 10.1016/j.virol.2015.03.013] [Citation(s) in RCA: 174] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 02/14/2015] [Accepted: 03/03/2015] [Indexed: 12/15/2022]
Abstract
Innate immune DNA sensing underpins many physiological and pathological responses to DNA, including anti-viral immunity to DNA viruses. Although it has been appreciated for many years that cytosolic DNA can evoke a type I interferon response, it is only within the past decade that the cellular mechanisms responsible for such a response have been defined. Here we review the discoveries that led to an appreciation of the existence of cytosolic DNA sensor proteins, and discuss two key such sensors, cGAS and IFI16, in detail. DNA sensors operate via STING, a protein shown to have a central role in controlling altered gene induction in response to DNA in vivo, and as such to be central to a rapidly expanding list of both protective and harmful responses to DNA. We also discuss recent insights into how and when DNA stimulates innate immunity, and highlight current outstanding questions in the DNA sensing field.
Collapse
|