51
|
Kay C, Wang R, Kirkby M, Man SM. Molecular mechanisms activating the NAIP-NLRC4 inflammasome: Implications in infectious disease, autoinflammation, and cancer. Immunol Rev 2020; 297:67-82. [PMID: 32729154 DOI: 10.1111/imr.12906] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Revised: 07/02/2020] [Accepted: 07/02/2020] [Indexed: 12/15/2022]
Abstract
Cytosolic innate immune sensing is a cornerstone of innate immunity in mammalian cells and provides a surveillance system for invading pathogens and endogenous danger signals. The NAIP-NLRC4 inflammasome responds to cytosolic flagellin, and the inner rod and needle proteins of the type 3 secretion system of bacteria. This complex induces caspase-1-dependent proteolytic cleavage of the proinflammatory cytokines IL-1β and IL-18, and the pore-forming protein gasdermin D, leading to inflammation and pyroptosis, respectively. Localized responses triggered by the NAIP-NLRC4 inflammasome are largely protective against bacterial pathogens, owing to several mechanisms, including the release of inflammatory mediators, liberation of concealed intracellular pathogens for killing by other immune mechanisms, activation of apoptotic caspases, caspase-7, and caspase-8, and expulsion of an entire infected cell from the mammalian host. In contrast, aberrant activation of the NAIP-NLRC4 inflammasome caused by de novo gain-of-function mutations in the gene encoding NLRC4 can lead to macrophage activation syndrome, neonatal enterocolitis, fetal thrombotic vasculopathy, familial cold autoinflammatory syndrome, and even death. Some of these clinical manifestations could be treated by therapeutics targeting inflammasome-associated cytokines. In addition, the NAIP-NLRC4 inflammasome has been implicated in the pathogenesis of colorectal cancer, melanoma, glioma, and breast cancer. However, no consensus has been reached on its function in the development of any cancer types. In this review, we highlight the latest advances in the activation mechanisms and structural assembly of the NAIP-NLRC4 inflammasome, and the functions of this inflammasome in different cell types. We also describe progress toward understanding the role of the NAIP-NLRC4 inflammasome in infectious diseases, autoinflammatory diseases, and cancer.
Collapse
Affiliation(s)
- Callum Kay
- Department of Immunology and Infectious Disease, The John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia
| | - Runli Wang
- Department of Immunology and Infectious Disease, The John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia
| | - Max Kirkby
- Department of Immunology and Infectious Disease, The John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia
| | - Si Ming Man
- Department of Immunology and Infectious Disease, The John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia
| |
Collapse
|
52
|
Anand PK. Lipids, inflammasomes, metabolism, and disease. Immunol Rev 2020; 297:108-122. [PMID: 32562313 DOI: 10.1111/imr.12891] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 05/19/2020] [Accepted: 05/27/2020] [Indexed: 12/19/2022]
Abstract
Inflammasomes are multi-protein complexes that regulate the cleavage of cysteine protease caspase-1, secretion of inflammatory cytokines, and induction of inflammatory cell death, pyroptosis. Several members of the nod-like receptor family assemble inflammasome in response to specific ligands. An exception to this is the NLRP3 inflammasome which is activated by structurally diverse entities. Recent studies have suggested that NLRP3 might be a sensor of cellular homeostasis, and any perturbation in distinct metabolic pathways results in the activation of this inflammasome. Lipid metabolism is exceedingly important in maintaining cellular homeostasis, and it is recognized that cells and tissues undergo extensive lipid remodeling during activation and disease. Some lipids are involved in instigating chronic inflammatory diseases, and new studies have highlighted critical upstream roles for lipids, particularly cholesterol, in regulating inflammasome activation implying key functions for inflammasomes in diseases with defective lipid metabolism. The focus of this review is to highlight how lipids regulate inflammasome activation and how this leads to the progression of inflammatory diseases. The key roles of cholesterol metabolism in the activation of inflammasomes have been comprehensively discussed. Besides, the roles of oxysterols, fatty acids, phospholipids, and lipid second messengers are also summarized in the context of inflammasomes. The overriding theme is that lipid metabolism has numerous but complex functions in inflammasome activation. A detailed understanding of this area will help us develop therapeutic interventions for diseases where dysregulated lipid metabolism is the underlying cause.
Collapse
Affiliation(s)
- Paras K Anand
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, UK
| |
Collapse
|
53
|
Rius-Rocabert S, Llinares Pinel F, Pozuelo MJ, García A, Nistal-Villan E. Oncolytic bacteria: past, present and future. FEMS Microbiol Lett 2020; 366:5521890. [PMID: 31226708 DOI: 10.1093/femsle/fnz136] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2019] [Accepted: 06/18/2019] [Indexed: 02/06/2023] Open
Abstract
More than a century ago, independent groups raised the possibility of using bacteria to selectively infect tumours. Such treatment induces an immune reaction that can cause tumour rejection and protect the patient against further recurrences. One of the first holistic approximations to use bacteria in cancer treatment was performed by William Coley, considered the father of immune-therapy, at the end of XIX century. Since then, many groups have used different bacteria to test their antitumour activity in animal models and patients. The basis for this reactivity implies that innate immune responses activated upon bacteria recognition, also react against the tumour. Different publications have addressed several aspects of oncolytic bacteria. In the present review, we will focus on revisiting the historical aspects using bacteria as oncolytic agents and how they led to the current clinical trials. In addition, we address the molecules present in oncolytic bacteria that induce specific toxic effects against the tumors as well as the activation of host immune responses in order to trigger antitumour immunity. Finally, we discuss future perspectives that could be considered in the different fields implicated in the implementation of this kind of therapy in order to improve the current use of bacteria as oncolytic agents.
Collapse
Affiliation(s)
- Sergio Rius-Rocabert
- Microbiology Section, Pharmaceutical and Health Science Department. Faculty of Pharmacy. Instituto de Medicina Molecular Aplicada (IMMA). San Pablo-CEU University. CEU Universities, Campus Montepríncipe. Boadilla del Monte, E-28668 Madrid, Spain
| | - Francisco Llinares Pinel
- Microbiology Section, Pharmaceutical and Health Science Department. Faculty of Pharmacy. Instituto de Medicina Molecular Aplicada (IMMA). San Pablo-CEU University. CEU Universities, Campus Montepríncipe. Boadilla del Monte, E-28668 Madrid, Spain
| | - Maria Jose Pozuelo
- Microbiology Section, Pharmaceutical and Health Science Department. Faculty of Pharmacy. Instituto de Medicina Molecular Aplicada (IMMA). San Pablo-CEU University. CEU Universities, Campus Montepríncipe. Boadilla del Monte, E-28668 Madrid, Spain
| | - Antonia García
- Centre for Metabolomics and Bioanalysis (CEMBIO), Chemistry and Biochemistry Department, Faculty of Pharmacy, San Pablo-CEU University, Boadilla del Monte, E-28668 Madrid, Spain
| | - Estanislao Nistal-Villan
- Microbiology Section, Pharmaceutical and Health Science Department. Faculty of Pharmacy. Instituto de Medicina Molecular Aplicada (IMMA). San Pablo-CEU University. CEU Universities, Campus Montepríncipe. Boadilla del Monte, E-28668 Madrid, Spain
| |
Collapse
|
54
|
Andrade WA, Zamboni DS. NLRC4 biology in immunity and inflammation. J Leukoc Biol 2020; 108:1117-1127. [PMID: 32531834 DOI: 10.1002/jlb.3mr0420-573r] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 04/29/2020] [Accepted: 05/05/2020] [Indexed: 12/14/2022] Open
Abstract
Inflammasomes are cytosolic multiprotein complexes that sense microbial infections or host cell damage, triggering cytokine production and a proinflammatory form of cell death, called pyroptosis. Whereas pyroptosis and cytokine production may often promote host resistance to infections, uncontrolled inflammasome activation leads to autoinflammatory diseases in humans. Among the multiple inflammasomes described, the neuronal apoptosis inhibitory protein/nucleotide-binding domain leucine-rich repeat-containing protein family caspase activation and recruitment domain-containing protein 4 (NLRC4) inflammasome emerged as a critical component for the restriction of bacterial infections. Accordingly, our understanding of this inflammasome advanced remarkably over the last 10 yr, expanding our knowledge about ligand-receptor interaction; cryo-EM structure; and downstream effectors and substrates, such as gasdermin-D, caspase-1, caspase-8, and caspase-7. In this review, we discuss recent advances on the biology of the NLRC4 inflammasome, in terms of structure and activation mechanisms, importance in bacterial and nonbacterial diseases, and the identification of NLRC4 gain-of-function mutations leading to NLRC4-associated autoinflammatory diseases in humans.
Collapse
Affiliation(s)
- Warrison A Andrade
- Department of Cell Biology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Ribeirão Preto, São Paulo, Brazil
| | - Dario S Zamboni
- Department of Cell Biology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Ribeirão Preto, São Paulo, Brazil
| |
Collapse
|
55
|
Bauer R, Rauch I. The NAIP/NLRC4 inflammasome in infection and pathology. Mol Aspects Med 2020; 76:100863. [PMID: 32499055 DOI: 10.1016/j.mam.2020.100863] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 04/30/2020] [Indexed: 12/16/2022]
Abstract
In this review we give an overview of the NAIP/NLRC4 activation mechanism as well as the described roles of this inflammasome, with a focus on in vivo infection and pathology. After ligand recognition by NAIP sensor proteins the NAIP/NLRC4 inflammasome forms through oligomerization with the NLRC4 adaptor to activate Caspase-1. The activating ligands are intracellular bacterial flagellin or type-3 secretion system components, delivered by pathogens. In vivo experiments indicate a role in macrophages during lung, spleen and liver infection and systemic sepsis like conditions, as well as in intestinal epithelial cells. Upon NAIP/NLRC4 activation in the intestine, epithelial cell extrusion is triggered in addition to the canonical inflammasome outcomes of cytokine cleavage and pyroptosis. Human patients with auto-activating mutations in NLRC4 present with an autoinflammatory syndrome including enterocolitis. Although one of the better understood inflammasomes in terms of mechanism, tissue specific functions of NAIP/NLRC4 are only beginning to be understood.
Collapse
Affiliation(s)
- Renate Bauer
- Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, OR, USA; Department of Biosciences, University of Salzburg, A-5020, Salzburg, Austria
| | - Isabella Rauch
- Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, OR, USA.
| |
Collapse
|
56
|
Abd El Maksoud AI, Elebeedy D, Abass NH, Awad AM, Nasr GM, Roshdy T, Khalil H. Methylomic Changes of Autophagy-Related Genes by Legionella Effector Lpg2936 in Infected Macrophages. Front Cell Dev Biol 2020; 7:390. [PMID: 32064256 PMCID: PMC6999459 DOI: 10.3389/fcell.2019.00390] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 12/23/2019] [Indexed: 12/26/2022] Open
Abstract
Legionella pneumophila (L. pneumophila) is a Gram-negative bacterium that infects the human respiratory tract causing Legionnaires' disease, a severe form of pneumonia. Recently, rising evidence indicated the ability of Legionella to regulate host defense via its type 4 secretion system including hundreds of effectors that promote intracellular bacterial replication. The host defense against such invaders includes autophagic machinery that is responsible for degradation events of invading pathogens and recycling of cell components. The interplay between host autophagy and Legionella infection has been reported, indicating the role of bacterial effectors in the regulation of autophagy during intracellular replication. Here, we investigated the potential impact of Legionella effector Lpg2936 in the regulation of host autophagy and its role in bacterial replication using mice-derived macrophages and human lung epithelial cells (A549 cells). First, monitoring of autophagic flux following infection revealed a marked reduction of Atg7 and LC3B expression profile and low accumulation levels of autophagy-related LC3-I, LC3-II, and the Atg12-Atg5 protein complex. A novel methyladenine alteration was observed due to irreversible changes of GATC motif to G(6 mA) TC in the promoter region of Atg7 and LC3B indicated by cleaved genomic-DNA using the N6 methyladenine-sensitive restriction enzyme DpnI. Interestingly, RNA interference (RNAi) of Lpg2936 in infected macrophages showed dramatic inhibition of bacterial replication by restoring the expression of autophagy-related proteins. This is accompanied by low production levels of bacterial-associated pro-inflammatory cytokines. Furthermore, a constructed Lpg2936 segment in the GFP expression vector was translocated in the host nucleus and successfully induced methyladenine changes in Atg7 and LC3B promoter region and subsequently regulated autophagy in A549 cells independent of infection. Finally, treatment with methylation inhibitors 5-AZA and (2)-Epigallocatechin-3-gallate (EGCG) was able to restore autophagy-related gene expression and to disrupt bacterial replication in infected macrophages. This cumulative evidence indicates the methylation effect of Legionella effector Lpg2936 on the host autophagy-related molecules Atg7 and LC3B and subsequent reduction in the expression levels of autophagy effectors during intracellular replication of L. pneumophila.
Collapse
Affiliation(s)
- Ahmed I. Abd El Maksoud
- Industrial Biotechnology Department, Genetic Engineering and Biotechnology Research Institute, University of Sadat City, Sadat City, Egypt
| | - Dalia Elebeedy
- College of Biotechnology, Misr University for Science and Technology (MUST), 6th of October City, Egypt
| | - Nasser H. Abass
- Department of Molecular Biology, Genetic Engineering and Biotechnology Research Institute, University of Sadat City, Sadat City, Egypt
| | - Ahmed M. Awad
- Department of Molecular Biology, Genetic Engineering and Biotechnology Research Institute, University of Sadat City, Sadat City, Egypt
| | - Ghada M. Nasr
- Molecular Diagnostics Department, Genetic Engineering and Biotechnology Research Institute, University of Sadat City, Sadat City, Egypt
| | - Tamer Roshdy
- Department of Molecular Biology, Genetic Engineering and Biotechnology Research Institute, University of Sadat City, Sadat City, Egypt
| | - Hany Khalil
- Department of Molecular Biology, Genetic Engineering and Biotechnology Research Institute, University of Sadat City, Sadat City, Egypt
| |
Collapse
|
57
|
An Advanced Risk Modeling Method to Estimate Legionellosis Risks Within a Diverse Population. WATER 2019. [DOI: 10.3390/w12010043] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Quantitative microbial risk assessment (QMRA) is a computational science leveraged to optimize infectious disease controls at both population and individual levels. Often, diverse populations will have different health risks based on a population’s susceptibility or outcome severity due to heterogeneity within the host. Unfortunately, due to a host homogeneity assumption in the microbial dose-response models’ derivation, the current QMRA method of modeling exposure volume heterogeneity is not an accurate method for pathogens such as Legionella pneumophila. Therefore, a new method to model within-group heterogeneity is needed. The method developed in this research uses USA national incidence rates from the Centers for Disease Control and Prevention (CDC) to calculate proxies for the morbidity ratio that are descriptive of the within-group variability. From these proxies, an example QMRA model is developed to demonstrate their use. This method makes the QMRA results more representative of clinical outcomes and increases population-specific precision. Further, the risks estimated demonstrate a significant difference between demographic groups known to have heterogeneous health outcomes after infection. The method both improves fidelity to the real health impacts resulting from L. pneumophila infection and allows for the estimation of severe disability-adjusted life years (DALYs) for Legionnaires’ disease, moderate DALYs for Pontiac fever, and post-acute DALYs for sequela after recovering from Legionnaires’ disease.
Collapse
|
58
|
Caution K, Young N, Robledo-Avila F, Krause K, Abu Khweek A, Hamilton K, Badr A, Vaidya A, Daily K, Gosu H, Anne MNK, Eltobgy M, Dakhlallah D, Argwal S, Estfanous S, Zhang X, Partida-Sanchez S, Gavrilin MA, Jarjour WN, Amer AO. Caspase-11 Mediates Neutrophil Chemotaxis and Extracellular Trap Formation During Acute Gouty Arthritis Through Alteration of Cofilin Phosphorylation. Front Immunol 2019; 10:2519. [PMID: 31803174 PMCID: PMC6874099 DOI: 10.3389/fimmu.2019.02519] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 10/09/2019] [Indexed: 12/21/2022] Open
Abstract
Gout is characterized by attacks of arthritis with hyperuricemia and monosodium urate (MSU) crystal-induced inflammation within joints. Innate immune responses are the primary drivers for tissue destruction and inflammation in gout. MSU crystals engage the Nlrp3 inflammasome, leading to the activation of caspase-1 and production of IL-1β and IL-18 within gout-affected joints, promoting the influx of neutrophils and monocytes. Here, we show that caspase-11−/− mice and their derived macrophages produce significantly reduced levels of gout-specific cytokines including IL-1β, TNFα, IL-6, and KC, while others like IFNγ and IL-12p70 are not altered. IL-1β induces the expression of caspase-11 in an IL-1 receptor-dependent manner in macrophages contributing to the priming of macrophages during sterile inflammation. The absence of caspase-11 reduced the ability of macrophages and neutrophils to migrate in response to exogenously injected KC in vivo. Notably, in vitro, caspase-11−/− neutrophils displayed random migration in response to a KC gradient when compared to their WT counterparts. This phenotype was associated with altered cofilin phosphorylation. Unlike their wild-type counterparts, caspase-11−/− neutrophils also failed to produce neutrophil extracellular traps (NETs) when treated with MSU. Together, this is the first report demonstrating that caspase-11 promotes neutrophil directional trafficking and function in an acute model of gout. Caspase-11 also governs the production of inflammasome-dependent and -independent cytokines from macrophages. Our results offer new, previously unrecognized functions for caspase-11 in macrophages and neutrophils that may apply to other neutrophil-mediated disease conditions besides gout.
Collapse
Affiliation(s)
- Kyle Caution
- Department of Microbial Infection and Immunity, The Ohio State University Medical Center, Columbus, OH, United States
| | - Nicholas Young
- Department of Rheumatology and Immunology, The Ohio State University Medical Center, Columbus, OH, United States
| | - Frank Robledo-Avila
- Center for Microbial Pathogenesis, Nationwide Children's Hospital, Columbus, OH, United States
| | - Kathrin Krause
- Department of Microbial Infection and Immunity, The Ohio State University Medical Center, Columbus, OH, United States
| | - Arwa Abu Khweek
- Department of Microbial Infection and Immunity, The Ohio State University Medical Center, Columbus, OH, United States.,Department of Biology and Biochemistry, Birzeit University, West Bank, Palestine
| | - Kaitlin Hamilton
- Department of Microbial Infection and Immunity, The Ohio State University Medical Center, Columbus, OH, United States
| | - Asmaa Badr
- Department of Microbial Infection and Immunity, The Ohio State University Medical Center, Columbus, OH, United States
| | - Anup Vaidya
- Department of Microbial Infection and Immunity, The Ohio State University Medical Center, Columbus, OH, United States
| | - Kylene Daily
- Department of Microbial Infection and Immunity, The Ohio State University Medical Center, Columbus, OH, United States
| | - Hawin Gosu
- Department of Microbial Infection and Immunity, The Ohio State University Medical Center, Columbus, OH, United States
| | - Midhun N K Anne
- Department of Microbial Infection and Immunity, The Ohio State University Medical Center, Columbus, OH, United States
| | - Mostafa Eltobgy
- Department of Microbial Infection and Immunity, The Ohio State University Medical Center, Columbus, OH, United States
| | - Duaa Dakhlallah
- Department of Microbiology, Immunology and Cell Biology, West Virginia University, Morgantown, WV, United States
| | - Sudha Argwal
- Department of Rheumatology and Immunology, The Ohio State University Medical Center, Columbus, OH, United States
| | - Shady Estfanous
- Department of Microbial Infection and Immunity, The Ohio State University Medical Center, Columbus, OH, United States
| | - Xiaoli Zhang
- Center for Biostatistics, The Ohio State University Medical Center, Columbus, OH, United States
| | | | - Mikhail A Gavrilin
- Department of Internal Medicine, The Ohio State University Medical Center, Columbus, OH, United States
| | - Wael N Jarjour
- Department of Rheumatology and Immunology, The Ohio State University Medical Center, Columbus, OH, United States
| | - Amal O Amer
- Department of Microbial Infection and Immunity, The Ohio State University Medical Center, Columbus, OH, United States
| |
Collapse
|
59
|
IRG1 and Inducible Nitric Oxide Synthase Act Redundantly with Other Interferon-Gamma-Induced Factors To Restrict Intracellular Replication of Legionella pneumophila. mBio 2019; 10:mBio.02629-19. [PMID: 31719183 PMCID: PMC6851286 DOI: 10.1128/mbio.02629-19] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Legionella pneumophila is one example among many species of pathogenic bacteria that replicate within mammalian macrophages during infection. The immune signaling factor interferon gamma (IFN-γ) blocks L. pneumophila replication in macrophages and is an essential component of the immune response to L. pneumophila and other intracellular pathogens. However, to date, no study has identified the exact molecular factors induced by IFN-γ that are required for its activity. We generated macrophages lacking different combinations of IFN-γ-induced genes in an attempt to find a genetic background in which there is a complete loss of IFN-γ-mediated restriction of L. pneumophila. We identified six genes that comprise the totality of the IFN-γ-dependent restriction of L. pneumophila replication in macrophages. Our results clarify the molecular basis underlying the potent effects of IFN-γ and highlight how redundancy downstream of IFN-γ is key to prevent exploitation of macrophages by pathogens. Interferon gamma (IFN-γ) restricts the intracellular replication of many pathogens, but the mechanism by which IFN-γ confers cell-intrinsic pathogen resistance remains unclear. For example, intracellular replication of the bacterial pathogen Legionella pneumophila in macrophages is potently curtailed by IFN-γ. However, consistent with prior studies, no individual genetic deficiency that we tested completely abolished IFN-γ-mediated control. Intriguingly, we observed that the glycolysis inhibitor 2-deoxyglucose (2DG) partially rescued L. pneumophila replication in IFN-γ-treated macrophages. 2DG inhibits glycolysis and triggers the unfolded protein response, but unexpectedly, it appears these effects are not responsible for perturbing the antimicrobial activity of IFN-γ. Instead, we found that 2DG rescues bacterial replication by inhibiting the expression of two key antimicrobial factors, inducible nitric oxide synthase (iNOS) and immune-responsive gene 1 (IRG1). Using immortalized and primary macrophages deficient in iNOS and IRG1, we confirmed that loss of both iNOS and IRG1, but not individual deficiency in either gene, partially reduced IFN-γ-mediated restriction of L. pneumophila. Further, using a combinatorial CRISPR/Cas9 mutagenesis approach, we found that mutation of iNOS and IRG1 in combination with four other genes (CASP11, IRGM1, IRGM3, and NOX2) resulted in a total loss of L. pneumophila restriction by IFN-γ in primary bone marrow macrophages. Our study defines a complete set of cell-intrinsic factors required for IFN-γ-mediated restriction of an intracellular bacterial pathogen and highlights the combinatorial strategy used by hosts to block bacterial replication in macrophages.
Collapse
|
60
|
Winsor N, Krustev C, Bruce J, Philpott DJ, Girardin SE. Canonical and noncanonical inflammasomes in intestinal epithelial cells. Cell Microbiol 2019; 21:e13079. [PMID: 31265745 DOI: 10.1111/cmi.13079] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 06/27/2019] [Accepted: 06/28/2019] [Indexed: 12/13/2022]
Abstract
Inflammasomes are cytosolic, multimeric protein complexes capable of activating pro-inflammatory cytokines such as IL-1β and IL-18, which play a key role in host defence. Inflammasome components are highly expressed in the intestinal epithelium. In recent years, studies have begun to demonstrate that epithelial-intrinsic inflammasomes play a critical role in regulating epithelial homeostasis, both by defending the epithelium from pathogenic insult and through the regulation of the mucosal environment. However, the majority of research regarding inflammasome activation has focused on professional immune cells, such as macrophages. Here, we present an overview of the current understanding of inflammasome function in epithelial cells and at mucosal surfaces and, in particular, in the intestine.
Collapse
Affiliation(s)
- Nathaniel Winsor
- Department of Immunology, University of Toronto, Toronto, Ontario, Canada
| | - Christian Krustev
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Jessica Bruce
- Department of Immunology, University of Toronto, Toronto, Ontario, Canada
- School of Biomedical Science and Pharmacy, University of Newcastle, Newcastle, New South Wales, Australia
| | - Dana J Philpott
- Department of Immunology, University of Toronto, Toronto, Ontario, Canada
| | - Stephen E Girardin
- Department of Immunology, University of Toronto, Toronto, Ontario, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| |
Collapse
|
61
|
Zhou CB, Fang JY. The role of pyroptosis in gastrointestinal cancer and immune responses to intestinal microbial infection. Biochim Biophys Acta Rev Cancer 2019; 1872:1-10. [DOI: 10.1016/j.bbcan.2019.05.001] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Revised: 04/18/2019] [Accepted: 05/01/2019] [Indexed: 01/04/2023]
|
62
|
Viewing Legionella pneumophila Pathogenesis through an Immunological Lens. J Mol Biol 2019; 431:4321-4344. [PMID: 31351897 DOI: 10.1016/j.jmb.2019.07.028] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 06/25/2019] [Accepted: 07/13/2019] [Indexed: 12/14/2022]
Abstract
Legionella pneumophila is the causative agent of the severe pneumonia Legionnaires' disease. L. pneumophila is ubiquitously found in freshwater environments, where it replicates within free-living protozoa. Aerosolization of contaminated water supplies allows the bacteria to be inhaled into the human lung, where L. pneumophila can be phagocytosed by alveolar macrophages and replicate intracellularly. The Dot/Icm type IV secretion system (T4SS) is one of the key virulence factors required for intracellular bacterial replication and subsequent disease. The Dot/Icm apparatus translocates more than 300 effector proteins into the host cell cytosol. These effectors interfere with a variety of cellular processes, thus enabling the bacterium to evade phagosome-lysosome fusion and establish an endoplasmic reticulum-derived Legionella-containing vacuole, which facilitates bacterial replication. In turn, the immune system has evolved numerous strategies to recognize intracellular bacteria such as L. pneumophila, leading to potent inflammatory responses that aid in eliminating infection. This review aims to provide an overview of L. pneumophila pathogenesis in the context of the host immune response.
Collapse
|
63
|
Gonçalves AV, Margolis SR, Quirino GFS, Mascarenhas DPA, Rauch I, Nichols RD, Ansaldo E, Fontana MF, Vance RE, Zamboni DS. Gasdermin-D and Caspase-7 are the key Caspase-1/8 substrates downstream of the NAIP5/NLRC4 inflammasome required for restriction of Legionella pneumophila. PLoS Pathog 2019; 15:e1007886. [PMID: 31251782 PMCID: PMC6622555 DOI: 10.1371/journal.ppat.1007886] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 07/11/2019] [Accepted: 06/03/2019] [Indexed: 11/24/2022] Open
Abstract
Inflammasomes are cytosolic multi-protein complexes that detect infection or cellular damage and activate the Caspase-1 (CASP1) protease. The NAIP5/NLRC4 inflammasome detects bacterial flagellin and is essential for resistance to the flagellated intracellular bacterium Legionella pneumophila. The effectors required downstream of NAIP5/NLRC4 to restrict bacterial replication remain unclear. Upon NAIP5/NLRC4 activation, CASP1 cleaves and activates the pore-forming protein Gasdermin-D (GSDMD) and the effector caspase-7 (CASP7). However, Casp1–/– (and Casp1/11–/–) mice are only partially susceptible to L. pneumophila and do not phenocopy Nlrc4–/–mice, because NAIP5/NLRC4 also activates CASP8 for restriction of L. pneumophila infection. Here we show that CASP8 promotes the activation of CASP7 and that Casp7/1/11–/– and Casp8/1/11–/– mice recapitulate the full susceptibility of Nlrc4–/– mice. Gsdmd–/– mice exhibit only mild susceptibility to L. pneumophila, but Gsdmd–/–Casp7–/– mice are as susceptible as the Nlrc4–/– mice. These results demonstrate that GSDMD and CASP7 are the key substrates downstream of NAIP5/NLRC4/CASP1/8 required for resistance to L. pneumophila. Inflammasomes are multi-protein complexes that detect infection and other stimuli and activate the Caspase-1 (CASP1) protease. The effectors required downstream of NAIP5/NLRC4 to restrict bacterial replication remain unclear. Active CASP1 cleaves and activates the pore-forming protein gasdermin D (GSDMD) to induce inflammation and cell death. We have previously shown that CASP8 is activated by the NAIP5/NLRC4 inflammasome independently of CASP1 and functions to restrict replication of the intracellular bacterium Legionella pneumophila. Here, we show that CASP7 is activated downstream of CASP8 and is required for CASP8-dependent restriction of L. pneumophila replication in macrophages and in vivo. In addition, CASP7 is also activated by CASP1. Taken together, these results imply that CASP7 and GSDMD are the two key caspase substrates downstream of NAIP5/NLRC4. In support of this hypothesis, we found that mice double deficient in CASP7 and GSDMD are more susceptible than the single knockouts and are as susceptible as the Nlrc4 deficient mice for restriction of L. pneumophila replication in vivo. Collectively, our data indicate that GSDMD and CASP7 are activated by CASP1 and induce cell death and restriction of bacterial infection. Therefore, GSDMD and multiple caspases (CASP1, CASP7 and CASP8) operate downstream of the NAIP5/NLRC4 inflammasome for restriction of infection by pathogenic bacteria.
Collapse
Affiliation(s)
- Augusto V. Gonçalves
- Department of Cell Biology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Shally R. Margolis
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, and Cancer Research Laboratory, University of California, Berkeley, California, United States of America
| | - Gustavo F. S. Quirino
- Department of Cell Biology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Danielle P. A. Mascarenhas
- Department of Cell Biology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Isabella Rauch
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, and Cancer Research Laboratory, University of California, Berkeley, California, United States of America
| | - Randilea D. Nichols
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, and Cancer Research Laboratory, University of California, Berkeley, California, United States of America
| | - Eduard Ansaldo
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, and Cancer Research Laboratory, University of California, Berkeley, California, United States of America
| | - Mary F. Fontana
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, and Cancer Research Laboratory, University of California, Berkeley, California, United States of America
| | - Russell E. Vance
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, and Cancer Research Laboratory, University of California, Berkeley, California, United States of America
- Howard Hughes Medical Institute, University of California, Berkeley, California, United States of America
- * E-mail: (REV); (DSZ)
| | - Dario S. Zamboni
- Department of Cell Biology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
- * E-mail: (REV); (DSZ)
| |
Collapse
|
64
|
Platnich JM, Muruve DA. NOD-like receptors and inflammasomes: A review of their canonical and non-canonical signaling pathways. Arch Biochem Biophys 2019; 670:4-14. [PMID: 30772258 DOI: 10.1016/j.abb.2019.02.008] [Citation(s) in RCA: 231] [Impact Index Per Article: 46.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 02/11/2019] [Accepted: 02/13/2019] [Indexed: 12/16/2022]
Abstract
The NOD-like receptor (NLR) family of proteins is a group of pattern recognition receptors (PRRs) known to mediate the initial innate immune response to cellular injury and stress. The NLRP proteins represent a fourteen-member subset of the NLR family that contains an N-terminal pyrin domain. Some NLRs are known to form multi-protein complexes known as inflammasomes. Inflammasomes consist of an NLR, the adaptor protein ASC, and the effector molecule pro-caspase-1. Once activated, these inflammasomes facilitate the cleavage and activation of caspase-1, which in turn mediates the cleavage of the pro-inflammatory cytokines IL-1β and IL-18 into their active and secreted forms. Activated caspase-1 also drives the cleavage of gasdermin D, which triggers an inflammatory form of cell death known as pyroptosis. Several NLRs are also known to possess non-canonical, inflammasome-independent functions, regulating a variety of signaling pathways. In this review, a thorough overview of both inflammasome-dependent and -independent NLR signaling will be presented, with highlights from the field as well as promising future directions and postulates based on the known science.
Collapse
Affiliation(s)
- Jaye M Platnich
- Department of Medicine, University of Calgary, Calgary, AB, Canada; Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada
| | - Daniel A Muruve
- Department of Medicine, University of Calgary, Calgary, AB, Canada; Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada.
| |
Collapse
|
65
|
Abstract
Legionella pneumophila is a gram-negative bacterium that infects many species of unicellular protozoa in freshwater environments. The human infection is accidental, and the bacteria may not have evolved strategies to bypass innate immune signaling in mammalian macrophages. Thus, L. pneumophila triggers many innate immune pathways including inflammasome activation. The inflammasomes are multimolecular platforms assembled in the host cell cytoplasm and lead to activation of inflammatory caspases. Inflammasome activation leads to secretion of inflammatory cytokines, such as IL-1β and IL-18, and an inflammatory form of cell death called pyroptosis, which initiates with the induction of a pore in the macrophage membranes. In this chapter we provide detailed protocols to evaluate Legionella-induced inflammasome activation in macrophages, including real-time pore formation assay, western blotting to detect activation of inflammatory caspases (cleavage and pulldown), and the measurement of inflammatory cytokines.
Collapse
Affiliation(s)
- Danielle P A Mascarenhas
- Department of Cell Biology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Dario S Zamboni
- Department of Cell Biology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil.
| |
Collapse
|
66
|
Overlapping Roles for Interleukin-36 Cytokines in Protective Host Defense against Murine Legionella pneumophila Pneumonia. Infect Immun 2018; 87:IAI.00583-18. [PMID: 30323031 PMCID: PMC6300640 DOI: 10.1128/iai.00583-18] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 10/12/2018] [Indexed: 01/19/2023] Open
Abstract
Legionella pneumophila causes life-threatening pneumonia culminating in acute lung injury. Innate and adaptive cytokines play an important role in host defense against L. pneumophila infection. Interleukin-36 (IL-36) cytokines are recently described members of the larger IL-1 cytokine family known to exert potent inflammatory effects. In this study, we elucidated the role for IL-36 cytokines in experimental pneumonia caused by L. pneumophila Intratracheal (i.t.) administration of L. pneumophila induced the upregulation of both IL-36α and IL-36γ mRNA and protein production in the lung. Compared to the findings for L. pneumophila-infected wild-type (WT) mice, the i.t. administration of L. pneumophila to IL-36 receptor-deficient (IL-36R-/-) mice resulted in increased mortality, a delay in lung bacterial clearance, increased L. pneumophila dissemination to extrapulmonary organs, and impaired glucose homeostasis. Impaired lung bacterial clearance in IL-36R-/- mice was associated with a significantly reduced accumulation of inflammatory cells and the decreased production of proinflammatory cytokines and chemokines. Ex vivo, reduced expression of costimulatory molecules and impaired M1 polarization were observed in alveolar macrophages isolated from infected IL-36R-/- mice compared to macrophages from WT mice. While L. pneumophila-induced mortality in IL-36α- or IL-36γ-deficient mice was not different from that in WT animals, antibody-mediated neutralization of IL-36γ in IL-36α-/- mice resulted in mortality similar to that observed in IL-36R-/- mice, indicating redundant and overlapping roles for these cytokines in experimental murine L. pneumophila pneumonia.
Collapse
|
67
|
A multicomponent toxin from Bacillus cereus incites inflammation and shapes host outcome via the NLRP3 inflammasome. Nat Microbiol 2018; 4:362-374. [PMID: 30531979 DOI: 10.1038/s41564-018-0318-0] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Accepted: 11/07/2018] [Indexed: 12/25/2022]
Abstract
Host recognition of microbial components is essential in mediating an effective immune response. Cytosolic bacteria must secure entry into the host cytoplasm to facilitate replication and, in doing so, liberate microbial ligands that activate cytosolic innate immune sensors and the inflammasome. Here, we identified a multicomponent enterotoxin, haemolysin BL (HBL), that engages activation of the inflammasome. This toxin is highly conserved among the human pathogen Bacillus cereus. The three subunits of HBL bind to the cell membrane in a linear order, forming a lytic pore and inducing activation of the NLRP3 inflammasome, secretion of interleukin-1β and interleukin-18, and pyroptosis. Mechanistically, the HBL-induced pore results in the efflux of potassium and triggers the activation of the NLRP3 inflammasome. Furthermore, HBL-producing B. cereus induces rapid inflammasome-mediated mortality. Pharmacological inhibition of the NLRP3 inflammasome using MCC950 prevents B. cereus-induced lethality. Overall, our results reveal that cytosolic sensing of a toxin is central to the innate immune recognition of infection. Therapeutic modulation of this pathway enhances host protection against deadly bacterial infections.
Collapse
|
68
|
Best AM, Abu Kwaik Y. Evasion of phagotrophic predation by protist hosts and innate immunity of metazoan hosts by Legionella pneumophila. Cell Microbiol 2018; 21:e12971. [PMID: 30370624 DOI: 10.1111/cmi.12971] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 10/08/2018] [Accepted: 10/24/2018] [Indexed: 12/18/2022]
Abstract
Legionella pneumophila is a ubiquitous environmental bacterium that has evolved to infect and proliferate within amoebae and other protists. It is thought that accidental inhalation of contaminated water particles by humans is what has enabled this pathogen to proliferate within alveolar macrophages and cause pneumonia. However, the highly evolved macrophages are equipped with more sophisticated innate defence mechanisms than are protists, such as the evolution of phagotrophic feeding into phagocytosis with more evolved innate defence processes. Not surprisingly, the majority of proteins involved in phagosome biogenesis (~80%) have origins in the phagotrophy stage of evolution. There are a plethora of highly evolved cellular and innate metazoan processes, not represented in protist biology, that are modulated by L. pneumophila, including TLR2 signalling, NF-κB, apoptotic and inflammatory processes, histone modification, caspases, and the NLRC-Naip5 inflammasomes. Importantly, L. pneumophila infects haemocytes of the invertebrate Galleria mellonella, kill G. mellonella larvae, and proliferate in and kill Drosophila adult flies and Caenorhabditis elegans. Although coevolution with protist hosts has provided a substantial blueprint for L. pneumophila to infect macrophages, we discuss the further evolutionary aspects of coevolution of L. pneumophila and its adaptation to modulate various highly evolved innate metazoan processes prior to becoming a human pathogen.
Collapse
Affiliation(s)
- Ashley M Best
- Department of Microbiology and Immunology, College of Medicine, University of Louisville, Louisville, Kentucky
| | - Yousef Abu Kwaik
- Department of Microbiology and Immunology, College of Medicine, University of Louisville, Louisville, Kentucky.,Center for Predictive Medicine, College of Medicine, University of Louisville, Louisville, Kentucky
| |
Collapse
|
69
|
Cytosolic Recognition of Microbes and Pathogens: Inflammasomes in Action. Microbiol Mol Biol Rev 2018; 82:82/4/e00015-18. [PMID: 30209070 DOI: 10.1128/mmbr.00015-18] [Citation(s) in RCA: 108] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Infection is a dynamic biological process underpinned by a complex interplay between the pathogen and the host. Microbes from all domains of life, including bacteria, viruses, fungi, and protozoan parasites, have the capacity to cause infection. Infection is sensed by the host, which often leads to activation of the inflammasome, a cytosolic macromolecular signaling platform that mediates the release of the proinflammatory cytokines interleukin-1β (IL-1β) and IL-18 and cleavage of the pore-forming protein gasdermin D, leading to pyroptosis. Host-mediated sensing of the infection occurs when pathogens inject or carry pathogen-associated molecular patterns (PAMPs) into the cytoplasm or induce damage that causes cytosolic liberation of danger-associated molecular patterns (DAMPs) in the host cell. Recognition of PAMPs and DAMPs by inflammasome sensors, including NLRP1, NLRP3, NLRC4, NAIP, AIM2, and Pyrin, initiates a cascade of events that culminate in inflammation and cell death. However, pathogens can deploy virulence factors capable of minimizing or evading host detection. This review presents a comprehensive overview of the mechanisms of microbe-induced activation of the inflammasome and the functional consequences of inflammasome activation in infectious diseases. We also explore the microbial strategies used in the evasion of inflammasome sensing at the host-microbe interaction interface.
Collapse
|
70
|
Krause K, Caution K, Badr A, Hamilton K, Saleh A, Patel K, Seveau S, Hall-Stoodley L, Hegazi R, Zhang X, Gavrilin MA, Amer AO. CASP4/caspase-11 promotes autophagosome formation in response to bacterial infection. Autophagy 2018; 14:1928-1942. [PMID: 30165781 PMCID: PMC6152495 DOI: 10.1080/15548627.2018.1491494] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
CASP4/caspase-11-dependent inflammasome activation is important for the clearance of various Gram-negative bacteria entering the host cytosol. Additionally, CASP4 modulates the actin cytoskeleton to promote the maturation of phagosomes harboring intracellular pathogens such as Legionella pneumophila but not those enclosing nonpathogenic bacteria. Nevertheless, this non-inflammatory role of CASP4 regarding the trafficking of vacuolar bacteria remains poorly understood. Macroautophagy/autophagy, a catabolic process within eukaryotic cells, is also implicated in the elimination of intracellular pathogens such as Burkholderia cenocepacia. Here we show that CASP4-deficient macrophages exhibit a defect in autophagosome formation in response to B. cenocepacia infection. The absence of CASP4 causes an accumulation of the small GTPase RAB7, reduced colocalization of B. cenocepacia with LC3 and acidic compartments accompanied by increased bacterial replication in vitro and in vivo. Together, our data reveal a novel role of CASP4 in regulating autophagy in response to B. cenocepacia infection.
Collapse
Affiliation(s)
- Kathrin Krause
- a Department of Microbial Infection and Immunity , Infectious Diseases Institute , Columbus , OH , USA
| | - Kyle Caution
- a Department of Microbial Infection and Immunity , Infectious Diseases Institute , Columbus , OH , USA
| | - Asmaa Badr
- a Department of Microbial Infection and Immunity , Infectious Diseases Institute , Columbus , OH , USA
| | - Kaitlin Hamilton
- a Department of Microbial Infection and Immunity , Infectious Diseases Institute , Columbus , OH , USA
| | - Abdulmuti Saleh
- a Department of Microbial Infection and Immunity , Infectious Diseases Institute , Columbus , OH , USA
| | - Khushbu Patel
- a Department of Microbial Infection and Immunity , Infectious Diseases Institute , Columbus , OH , USA
| | - Stephanie Seveau
- a Department of Microbial Infection and Immunity , Infectious Diseases Institute , Columbus , OH , USA
| | - Luanne Hall-Stoodley
- a Department of Microbial Infection and Immunity , Infectious Diseases Institute , Columbus , OH , USA
| | - Rana Hegazi
- a Department of Microbial Infection and Immunity , Infectious Diseases Institute , Columbus , OH , USA
| | - Xiaoli Zhang
- b Center for Biostatistics, The Ohio State University , Columbus , OH , USA
| | - Mikhail A Gavrilin
- c Department of Internal Medicine , The Ohio State University , Columbus , OH , USA
| | - Amal O Amer
- a Department of Microbial Infection and Immunity , Infectious Diseases Institute , Columbus , OH , USA
| |
Collapse
|
71
|
Triggers of NLRC4 and AIM2 inflammasomes induce porcine IL-1β secretion. Vet Res Commun 2018; 42:265-273. [DOI: 10.1007/s11259-018-9729-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 07/19/2018] [Indexed: 12/27/2022]
|
72
|
de la Roche M, Hamilton C, Mortensen R, Jeyaprakash AA, Ghosh S, Anand PK. Trafficking of cholesterol to the ER is required for NLRP3 inflammasome activation. J Cell Biol 2018; 217:3560-3576. [PMID: 30054450 PMCID: PMC6168277 DOI: 10.1083/jcb.201709057] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 12/19/2017] [Accepted: 07/13/2018] [Indexed: 01/01/2023] Open
Abstract
Cellular lipid metabolism is being increasingly recognized to influence inflammatory responses. de la Roche et al. reveal that cellular sterol trafficking to the endoplasmic reticulum is required for the assembly and the activation of the NLRP3 inflammasome, thereby coupling lipid homeostasis to innate immune signaling. Cellular lipids determine membrane integrity and fluidity and are being increasingly recognized to influence immune responses. Cellular cholesterol requirements are fulfilled through biosynthesis and uptake programs. In an intricate pathway involving the lysosomal cholesterol transporter NPC1, the sterol gets unequally distributed across intracellular compartments. By using pharmacological and genetic approaches targeting NPC1, we reveal that blockade of cholesterol trafficking through the late endosome–lysosome pathway blunts NLRP3 inflammasome activation. Altered cholesterol localization at the plasma membrane (PM) in Npc1−/− cells abrogated AKT–mTOR signaling by TLR4. However, the inability to activate the NLRP3 inflammasome was traced to perturbed cholesterol trafficking to the ER but not the PM. Accordingly, acute cholesterol depletion in the ER membranes by statins abrogated casp-1 activation and IL-1β secretion and ablated NLRP3 inflammasome assembly. By contrast, assembly and activation of the AIM2 inflammasome progressed unrestricted. Together, this study reveals ER sterol levels as a metabolic rheostat for the activation of the NLRP3 inflammasome.
Collapse
Affiliation(s)
- Marianne de la Roche
- Infectious Diseases and Immunity, Department of Medicine, Imperial College London, London, UK
| | - Claire Hamilton
- Infectious Diseases and Immunity, Department of Medicine, Imperial College London, London, UK
| | - Rebecca Mortensen
- Infectious Diseases and Immunity, Department of Medicine, Imperial College London, London, UK
| | - A Arockia Jeyaprakash
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Sanjay Ghosh
- Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - Paras K Anand
- Infectious Diseases and Immunity, Department of Medicine, Imperial College London, London, UK
| |
Collapse
|
73
|
Legionella pneumophila Is Directly Sensitive to 2-Deoxyglucose-Phosphate via Its UhpC Transporter but Is Indifferent to Shifts in Host Cell Glycolytic Metabolism. J Bacteriol 2018; 200:JB.00176-18. [PMID: 29784886 DOI: 10.1128/jb.00176-18] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2018] [Accepted: 05/15/2018] [Indexed: 12/14/2022] Open
Abstract
Toll-like receptor (TLR) stimulation induces a pronounced shift to increased glycolytic metabolism in mammalian macrophages. We observed that bone marrow-derived macrophages (BMMs) increase glycolysis in response to infection with Legionella pneumophila, but the role of host macrophage glycolysis in terms of intracellular L. pneumophila replication is not currently understood. Treatment with 2-deoxyglucose (2DG) blocks L. pneumophila replication in mammalian macrophages but has no effect on bacteria grown in broth. In addition, we found that 2DG had no effect on bacteria grown in amoebae. We used a serial enrichment strategy to reveal that the effect of 2DG on L. pneumophila in macrophages requires the L. pneumophila hexose-phosphate transporter UhpC. Experiments with UhpC-deficient L. pneumophila revealed that mutant bacteria are also resistant to growth inhibition following treatment with phosphorylated 2DG in broth, suggesting that the inhibitory effect of 2DG on L. pneumophila in mammalian cells requires 2DG phosphorylation. UhpC-deficient L. pneumophila replicates without a growth defect in BMMs and protozoan host cells and also replicates without a growth defect in BMMs treated with 2DG. Our data indicate that neither TLR signaling-dependent increased macrophage glycolysis nor inhibition of macrophage glycolysis has a substantial effect on intracellular L. pneumophila replication. These results are consistent with the view that L. pneumophila can employ diverse metabolic strategies to exploit its host cells.IMPORTANCE We explored the relationship between macrophage glycolysis and replication of an intracellular bacterial pathogen, Legionella pneumophila Previous studies demonstrated that a glycolysis inhibitor, 2-deoxyglucose (2DG), blocks replication of L. pneumophila during infection of macrophages, leading to speculation that L. pneumophila may exploit macrophage glycolysis. We isolated L. pneumophila mutants resistant to the inhibitory effect of 2DG in macrophages, identifying a L. pneumophila hexose-phosphate transporter, UhpC, that is required for bacterial sensitivity to 2DG during infection. Our results reveal how a bacterial transporter mediates the direct antimicrobial effect of a toxic metabolite. Moreover, our results indicate that neither induction nor impairment of host glycolysis inhibits intracellular replication of L. pneumophila, which is consistent with a view of L. pneumophila as a metabolic generalist.
Collapse
|
74
|
AIM2 Engages Active but Unprocessed Caspase-1 to Induce Noncanonical Activation of the NLRP3 Inflammasome. Cell Rep 2018; 20:794-805. [PMID: 28746866 DOI: 10.1016/j.celrep.2017.06.086] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 05/10/2017] [Accepted: 06/28/2017] [Indexed: 11/21/2022] Open
Abstract
Inflammasomes are multimeric protein complexes that initiate inflammatory cascades. Their activation is a hallmark of many infectious or inflammatory diseases. Their composition and activity are specified by proinflammatory stimuli. For example, the NLRP3 inflammasome is activated in response to cell damage and K+ efflux, whereas the AIM2 inflammasome is activated in response to cytosolic DNA. We used Legionella pneumophila, an intracellular bacterial pathogen that activates multiple inflammasomes, to elucidate the molecular mechanisms regulating inflammasome activation during infection. Upon infection, the AIM2 inflammasome engaged caspase-1 to induce pore formation in the cell membrane, which then caused K+-efflux-mediated activation of NLRP3. Thus, the AIM2 inflammasome amplifies signals of infection, triggering noncanonical activation of NLRP3. During infection, AIM2 and caspase-11 induced membrane damage, which was sufficient and essential for activating the NLRP3 inflammasome. Our data reveal that different inflammasomes regulate one another's activity to ensure an effective immune response to infection.
Collapse
|
75
|
Bhattarai D, Worku T, Dad R, Rehman ZU, Gong X, Zhang S. Mechanism of pattern recognition receptors (PRRs) and host pathogen interplay in bovine mastitis. Microb Pathog 2018; 120:64-70. [PMID: 29635052 DOI: 10.1016/j.micpath.2018.04.010] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 04/01/2018] [Accepted: 04/06/2018] [Indexed: 02/08/2023]
Abstract
Bacterial infection in the mammary gland parenchyma induces local and subsequently systemic inflammation that results in a complex disease. Mastitis in bovine is the result of various factors which function together. This review is aimed to analyze the factors involved in the pathogenesis of common bacterial species for bovine mastitis. The bacterial growth patterns, signaling pathway and the pathogen-associated molecular patterns (PAMPs) which activate immune responses is discussed. Clear differences in bacterial infection pattern are shown between bacterial species and illustrated TLRs, NLRs and RLGs molecular mechanism for the initiation of intramammary infection. The underlying reasons for the differences and the resulting host response are analyzed. Understandings of the mechanisms that activate and regulate these responses are central to the development of efficient anticipatory and treatment management. The knowledge of bovine mammary gland to common mastitis causing pathogens with possible immune mechanism could be a new conceptual understanding for the prospect of mastitis control program.
Collapse
Affiliation(s)
- Dinesh Bhattarai
- Key Laboratory of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, 430071, China.
| | - Tesfaye Worku
- Key Laboratory of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, 430071, China
| | - Rahim Dad
- Key Laboratory of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, 430071, China
| | - Zia Ur Rehman
- Key Laboratory of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, 430071, China
| | - Xiaoling Gong
- The Agricultural Broadcasting and Television School in Hubei Province, Wuhan, 430064, China
| | - Shujun Zhang
- Key Laboratory of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, 430071, China.
| |
Collapse
|
76
|
Karki R, Lee E, Place D, Samir P, Mavuluri J, Sharma BR, Balakrishnan A, Malireddi RKS, Geiger R, Zhu Q, Neale G, Kanneganti TD. IRF8 Regulates Transcription of Naips for NLRC4 Inflammasome Activation. Cell 2018; 173:920-933.e13. [PMID: 29576451 DOI: 10.1016/j.cell.2018.02.055] [Citation(s) in RCA: 124] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 01/17/2018] [Accepted: 02/21/2018] [Indexed: 02/08/2023]
Abstract
Inflammasome activation is critical for host defenses against various microbial infections. Activation of the NLRC4 inflammasome requires detection of flagellin or type III secretion system (T3SS) components by NLR family apoptosis inhibitory proteins (NAIPs); yet how this pathway is regulated is unknown. Here, we found that interferon regulatory factor 8 (IRF8) is required for optimal activation of the NLRC4 inflammasome in bone-marrow-derived macrophages infected with Salmonella Typhimurium, Burkholderia thailandensis, or Pseudomonas aeruginosa but is dispensable for activation of the canonical and non-canonical NLRP3, AIM2, and Pyrin inflammasomes. IRF8 governs the transcription of Naips to allow detection of flagellin or T3SS proteins to mediate NLRC4 inflammasome activation. Furthermore, we found that IRF8 confers protection against bacterial infection in vivo, owing to its role in inflammasome-dependent cytokine production and pyroptosis. Altogether, our findings suggest that IRF8 is a critical regulator of NAIPs and NLRC4 inflammasome activation for defense against bacterial infection.
Collapse
Affiliation(s)
- Rajendra Karki
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Ein Lee
- 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
| | - David Place
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Parimal Samir
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Jayadev Mavuluri
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Bhesh Raj Sharma
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Arjun Balakrishnan
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | | | - Rechel Geiger
- Department of Immunology, 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
| | - Geoffrey Neale
- Hartwell Center for Bioinformatics & Biotechnology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | | |
Collapse
|
77
|
Ramachandran RA, Lupfer C, Zaki H. The Inflammasome: Regulation of Nitric Oxide and Antimicrobial Host Defence. Adv Microb Physiol 2018; 72:65-115. [PMID: 29778217 DOI: 10.1016/bs.ampbs.2018.01.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Nitric oxide (NO) is a gaseous signalling molecule that plays diverse physiological functions including antimicrobial host defence. During microbial infection, NO is synthesized by inducible NO synthase (iNOS), which is expressed by host immune cells through the recognition of microbial pattern molecules. Therefore, sensing pathogens or their pattern molecules by pattern recognition receptors (PRRs), which are located at the cell surface, endosomal and phagosomal compartment, or in the cytosol, is key in inducing iNOS and eliciting antimicrobial host defence. A group of cytosolic PRRs is involved in inducing NO and other antimicrobial molecules by forming a molecular complex called the inflammasome. Assembled inflammasomes activate inflammatory caspases, such as caspase-1 and caspase-11, which in turn process proinflammatory cytokines IL-1β and IL-18 into their mature forms and induce pyroptotic cell death. IL-1β and IL-18 play a central role in immunity against microbial infection through activation and recruitment of immune cells, induction of inflammatory molecules, and regulation of antimicrobial mediators including NO. Interestingly, NO can also regulate inflammasome activity in an autocrine and paracrine manner. Here, we discuss molecular mechanisms of inflammasome formation and the inflammasome-mediated regulation of host defence responses during microbial infections.
Collapse
Affiliation(s)
| | | | - Hasan Zaki
- UT Southwestern Medical Center, Dallas, TX, United States.
| |
Collapse
|
78
|
NOD-like receptor(s) and host immune responses with Pseudomonas aeruginosa infection. Inflamm Res 2018; 67:479-493. [PMID: 29353310 DOI: 10.1007/s00011-018-1132-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 01/12/2018] [Accepted: 01/16/2018] [Indexed: 01/01/2023] Open
Abstract
INTRODUCTION Molecular mechanisms underlying the interactions between Pseudomonas aeruginosa, the common opportunistic pathogen in cystic fibrosis individuals, and host induce a number of marked inflammatory responses and associate with complex therapeutic problems due to bacterial resistance to antibiotics in chronic stage of infection. METHODS Pseudomonas aeruginosa is recognized by number of pattern recognition receptors (PRRs); NOD-like receptors (NLRs) are a class of PRRs, which can recognize a variety of endogenous and exogenous ligands, thereby playing a critical role in innate immunity. RESULTS NLR activation initiates forming of a multi-protein complex called inflammasome that induces activation of caspase-1 and resulted in cleavage of pro-inflammatory cytokines interleukin (IL)-1β and IL-18. When the IL-1β is secreted excessively, this causes tissue damage and extensive inflammatory responses that are potentially hazardous for the host. CONCLUSIONS Recent evidence has laid out inflammasome-forming NLR far beyond inflammation. This review summarizes current knowledge regarding the various roles played by different NLRs and associated down-signals, either in recognition of P. aeruginosa or may be associated with such bacterial pathogen infection, which may relate to for the complexity of lung diseases caused by P. aeruginosa.
Collapse
|
79
|
Ravi Kumar S, Paudel S, Ghimire L, Bergeron S, Cai S, Zemans RL, Downey GP, Jeyaseelan S. Emerging Roles of Inflammasomes in Acute Pneumonia. Am J Respir Crit Care Med 2018; 197:160-171. [PMID: 28930487 PMCID: PMC5768907 DOI: 10.1164/rccm.201707-1391pp] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 09/19/2017] [Indexed: 12/11/2022] Open
Affiliation(s)
- Sangeetha Ravi Kumar
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana
| | - Sagar Paudel
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana
| | - Laxman Ghimire
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana
| | - Scott Bergeron
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana
| | - Shanshan Cai
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana
| | - Rachel L. Zemans
- Division of Pulmonary, Sleep, and Critical Care Medicine, Department of Medicine, National Jewish Health, Denver, Colorado
- Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado, Denver, Aurora, Colorado; and
| | - Gregory P. Downey
- Division of Pulmonary, Sleep, and Critical Care Medicine, Department of Medicine, National Jewish Health, Denver, Colorado
- Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado, Denver, Aurora, Colorado; and
| | - Samithamby Jeyaseelan
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana
- Section of Pulmonary and Critical Care Medicine, Department of Medicine, Louisiana State University Health Sciences Center, New Orleans, Louisiana
| |
Collapse
|
80
|
Abstract
Inflammasome signalling is an emerging pillar of innate immunity and has a central role in the regulation of gastrointestinal health and disease. Activation of the inflammasome complex mediates both the release of the pro-inflammatory cytokines IL-1β and IL-18 and the execution of a form of inflammatory cell death known as pyroptosis. In most cases, these mediators of inflammation provide protection against bacterial, viral and protozoal infections. However, unchecked inflammasome activities perpetuate chronic inflammation, which underpins the molecular and pathophysiological basis of gastritis, IBD, upper and lower gastrointestinal cancer, nonalcoholic fatty liver disease and obesity. Studies have also highlighted an inflammasome signature in the maintenance of gut microbiota and gut-brain homeostasis. Harnessing the immunomodulatory properties of the inflammasome could transform clinical practice in the treatment of acute and chronic gastrointestinal and extragastrointestinal diseases. This Review presents an overview of inflammasome biology in gastrointestinal health and disease and describes the value of experimental and pharmacological intervention in the treatment of inflammasome-associated clinical manifestations.
Collapse
|
81
|
Cordero MD, Alcocer-Gómez E. Inflammasome in the Pathogenesis of Pulmonary Diseases. EXPERIENTIA SUPPLEMENTUM (2012) 2018; 108:111-151. [PMID: 30536170 PMCID: PMC7123416 DOI: 10.1007/978-3-319-89390-7_6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Lung diseases are common and significant causes of illness and death around the world. Inflammasomes have emerged as an important regulator of lung diseases. The important role of IL-1 beta and IL-18 in the inflammatory response of many lung diseases has been elucidated. The cleavage to turn IL-1 beta and IL-18 from their precursors into the active forms is tightly regulated by inflammasomes. In this chapter, we structurally review current evidence of inflammasome-related components in the pathogenesis of acute and chronic lung diseases, focusing on the "inflammasome-caspase-1-IL-1 beta/IL-18" axis.
Collapse
Affiliation(s)
- Mario D. Cordero
- Department of Physiology, Institute of Nutrition and Food Technology “José Mataix”, Biomedical Research Center (CIBM), University of Granada, Armilla, Spain
| | - Elísabet Alcocer-Gómez
- Departamento de Psicología Experimental, Facultad de Psicología, Universidad de Sevilla, Seville, Spain
| |
Collapse
|
82
|
Marín-Aguilar F, Ruiz-Cabello J, Cordero MD. Aging and the Inflammasomes. EXPERIENTIA SUPPLEMENTUM (2012) 2018; 108:303-320. [PMID: 30536177 DOI: 10.1007/978-3-319-89390-7_13] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The inflammasomes are innate immune system sensors that control the activation of caspase-1 and induce inflammation in response to infectious microbes and molecules originating from host proteins, leading to the release of pro-inflammatory cytokines, Il1b and IL18, and a particular inflammatory type of cell death termed pyroptosis. It is broadly considered that chronic inflammation may be a common link in age-related diseases, aging being the greatest risk factor for the development of chronic diseases. In this sense, we discuss the role of inflammasomes in non-infectious inflammation and their interest in aging and age-related diseases.
Collapse
Affiliation(s)
- Fabiola Marín-Aguilar
- Research Laboratory, Oral Medicine Department, University of Sevilla, Sevilla, Spain
| | - Jesús Ruiz-Cabello
- CIC biomaGUNE, San Sebastian-Donostia, Spain, Madrid, Spain
- CIC biomaGUNE, Madrid, Spain
- IKERBASQUE, Basque Foundation for Science, Biscay, Spain
- CIBER de Enfermedades Respiratorias (CIBERES), Madrid, Spain
- Universidad Complutense Madrid, Madrid, Spain
| | - Mario D Cordero
- Department of Physiology, Institute of Nutrition and Food Technology "José Mataix", Biomedical Research Center (CIBM), University of Granada, Armilla, Spain.
| |
Collapse
|
83
|
Seo DW, Cho YI, Gu S, Kim DH, Yi YJ, Lee SM. A hot-water extract of Sanguisorba officinalis ameliorates endotoxin-induced septic shock by inhibiting inflammasome activation. Microbiol Immunol 2017; 62:44-54. [PMID: 29193282 DOI: 10.1111/1348-0421.12557] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Revised: 11/15/2017] [Accepted: 11/24/2017] [Indexed: 11/28/2022]
Abstract
The inflammasome is a multiprotein signaling complex that mediates inflammatory innate immune responses through caspase 1 activation and subsequent IL-1β secretion. However, because its aberrant activation often leads to inflammatory diseases, targeting the inflammasome holds promise for the treatment of inflammation-related diseases. In this study, it was found that a hot-water extract of Sanguisorba officinalis (HSO) suppresses inflammasome activation triggered by adenosine 5'-triphosphate, nigericin, microbial pathogens, and double stranded DNA in bone marrow-derived macrophages. HSO was found to significantly suppress IL-1β production in a dose-dependent manner; this effect correlated well with small amounts of caspase 1 and little ASC pyroptosome formation in HSO-treated cells. The anti-inflammatory activity of HSO was further confirmed in a mouse model of endotoxin-induced septic shock. Oral administration of HSO reduced IL-1β titers in the serum and peritoneal cavity, increasing the survival rate. Taken together, our results suggest that HSO is an inhibits inflammasome activation through nucleotide-binding domain and leucine-rich repeat pyrin domain 3, nucleotide-binding domain and leucine-rich repeat caspase recruitment domain 4 and absent in melanoma 2 pathways, and may be useful for treatment of inflammasome-mediated diseases.
Collapse
Affiliation(s)
- Dong-Won Seo
- Gyeongbuk Institute for Bio industry, Andong-si, Gyeongbuk 760-380, South Korea
| | - Yong-Il Cho
- Department of Animal Science and Technology, Suncheon National University, 255 Jungang-ro, Suncheon-si, Jeollanam-do 57922, South Korea
| | - Suna Gu
- Division of Biotechnology, College of Environmental and Bioresources, Chonbuk National University, Iksan-si, Jeollabuk-do 570-752, South Korea
| | - Da-Hee Kim
- Division of Biotechnology, College of Environmental and Bioresources, Chonbuk National University, Iksan-si, Jeollabuk-do 570-752, South Korea
| | - Young-Joo Yi
- Division of Biotechnology, College of Environmental and Bioresources, Chonbuk National University, Iksan-si, Jeollabuk-do 570-752, South Korea
| | - Sang-Myeong Lee
- Division of Biotechnology, College of Environmental and Bioresources, Chonbuk National University, Iksan-si, Jeollabuk-do 570-752, South Korea
| |
Collapse
|
84
|
Dolasia K, Bisht MK, Pradhan G, Udgata A, Mukhopadhyay S. TLRs/NLRs: Shaping the landscape of host immunity. Int Rev Immunol 2017; 37:3-19. [PMID: 29193992 DOI: 10.1080/08830185.2017.1397656] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Innate immune system provides the first line of defense against pathogenic organisms. It has a varied and large collection of molecules known as pattern recognition receptors (PRRs) which can tackle the pathogens promptly and effectively. Toll-like receptors (TLRs) and NOD-like receptors (NLRs) are members of the PRR family that recognize pathogen associated molecular patterns (PAMPs) and play pivotal roles to mediate defense against infections from bacteria, fungi, virus and various other pathogens. In this review, we discuss the critical roles of TLRs and NLRs in the regulation of host immune-effector functions such as cytokine production, phagosome-lysosome fusion, inflammasome activation, autophagy, antigen presentation, and B and T cell immune responses that are known to be essential for mounting a protective immune response against the pathogens. This review may be helpful to design TLRs/NLRs based immunotherapeutics to control various infections and pathophysiological disorders.
Collapse
Affiliation(s)
- Komal Dolasia
- a Laboratory of Molecular Cell Biology, Centre for DNA Fingerprinting and Diagnostics (CDFD) , Tuljaguda Complex, Nampally, Hyderabad , India
| | - Manoj K Bisht
- a Laboratory of Molecular Cell Biology, Centre for DNA Fingerprinting and Diagnostics (CDFD) , Tuljaguda Complex, Nampally, Hyderabad , India
| | - Gourango Pradhan
- a Laboratory of Molecular Cell Biology, Centre for DNA Fingerprinting and Diagnostics (CDFD) , Tuljaguda Complex, Nampally, Hyderabad , India
| | - Atul Udgata
- a Laboratory of Molecular Cell Biology, Centre for DNA Fingerprinting and Diagnostics (CDFD) , Tuljaguda Complex, Nampally, Hyderabad , India
| | - Sangita Mukhopadhyay
- a Laboratory of Molecular Cell Biology, Centre for DNA Fingerprinting and Diagnostics (CDFD) , Tuljaguda Complex, Nampally, Hyderabad , India
| |
Collapse
|
85
|
Sarvestani ST, McAuley JL. The role of the NLRP3 inflammasome in regulation of antiviral responses to influenza A virus infection. Antiviral Res 2017; 148:32-42. [PMID: 29097227 DOI: 10.1016/j.antiviral.2017.10.020] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 10/20/2017] [Accepted: 10/27/2017] [Indexed: 12/25/2022]
Abstract
The innate immune system provides the host with both a dynamic barrier to prevent infection and a means to which rapid anti-microbial responses can be mounted. The inflammasome pathway is a critical host early response mechanism that enables detection of pathogens and initiates production of inflammatory cytokines, inducing recruitment of effector cells to the site of infection. The complete mechanism of inflammasome activation requires two signals: an initial priming step upon detection of pathogen, followed by activation of intracellular pattern recognition receptors critical to the formation of the inflammasome complex. The inflammasome complex is made of intracellular multiprotein oligomers which includes a sensor protein such as the nucleotide-binding oligomerization domain (NOD) like receptor proteins (NLRP), and an adapter protein, ASC, which critically activates pro-caspase-1. The mature caspase-1 then proteolytically cleaves cytosolic pro-IL-1β and pro-IL-18, which are then secreted as inflammatory cytokines that activate the inflammatory arm of the immune response to infection. Active caspase-1 also results in pyroptosis, which is a form of cell death triggered by inflammation. The induction and activation of IL-1β and IL-18 are considered critical signatures for inflammasome activation. With focus upon influenza A virus infection, this review will address present knowledge on the mechanisms of inflammasome complex activation, particularly how the viral components modulate activation of the cytosolic NOD-like receptor protein-3 (NLRP3)-dependent inflammasome complex. We also discuss potential therapeutic strategies that target the inflammasome to ameliorate illness, as well as novel methods of vaccination that target inflammasome stimulation with the aim to increase efficacy.
Collapse
Affiliation(s)
- Soroush T Sarvestani
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, 3000, Australia
| | - Julie L McAuley
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, 3000, Australia.
| |
Collapse
|
86
|
Naujoks J, Lippmann J, Suttorp N, Opitz B. Innate sensing and cell-autonomous resistance pathways in Legionella pneumophila infection. Int J Med Microbiol 2017; 308:161-167. [PMID: 29097162 DOI: 10.1016/j.ijmm.2017.10.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2017] [Revised: 10/20/2017] [Accepted: 10/23/2017] [Indexed: 12/20/2022] Open
Abstract
Legionella pneumophila is a facultative intracellular bacterium which can cause a severe pneumonia called Legionnaires' disease after inhalation of contaminated water droplets and replication in alveolar macrophages. The innate immune system is generally able to sense and -in most cases- control L. pneumophila infection. Comorbidities and genetic risk factors, however, can compromise the immune system and high infection doses might overwhelm its capacity, thereby enabling L. pneumophila to grow and disseminate inside the lung. The innate immune system mediates sensing of L. pneumophila by employing e.g. NOD-like receptors (NLRs), Toll-like receptors (TLRs), as well as the cGAS/STING pathway to stimulate death of infected macrophages as well as production of proinflammatory cytokines and interferons (IFNs). Control of pulmonary L. pneumophila infection is largely mediated by inflammasome-, TNFα- and IFN-dependent macrophage-intrinsic resistance mechanisms. This article summarizes the current knowledge of innate immune responses to L. pneumophila infection in general, and of macrophage-intrinsic defense mechanisms in particular.
Collapse
Affiliation(s)
- Jan Naujoks
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Internal Medicine/Infectious Diseases and Pulmonary Medicine, Augustenburger Platz 1, 13353 Berlin, Germany
| | - Juliane Lippmann
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Internal Medicine/Infectious Diseases and Pulmonary Medicine, Augustenburger Platz 1, 13353 Berlin, Germany
| | - Norbert Suttorp
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Internal Medicine/Infectious Diseases and Pulmonary Medicine, Augustenburger Platz 1, 13353 Berlin, Germany
| | - Bastian Opitz
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Internal Medicine/Infectious Diseases and Pulmonary Medicine, Augustenburger Platz 1, 13353 Berlin, Germany; German Center for Lung Research (DZL), Germany.
| |
Collapse
|
87
|
How Inflammasomes Inform Adaptive Immunity. J Mol Biol 2017; 430:217-237. [PMID: 28987733 DOI: 10.1016/j.jmb.2017.09.019] [Citation(s) in RCA: 101] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Revised: 09/27/2017] [Accepted: 09/28/2017] [Indexed: 02/07/2023]
Abstract
An immune response consists of a finely orchestrated interplay between initial recognition of potential microbial threats by the innate immune system and subsequent licensed adaptive immune neutralization. The initial recognition integrates environmental cues derived from pathogen-associated molecular patterns and cell-intrinsic damage-associated molecular patterns to contextualize the insult and inform a tailored adaptive response via T and B lymphocytes. While there are much data to support the role of transcriptional responses downstream of pattern recognition receptors in informing the adaptive immune response, markedly less attention has been paid to the role of post-translational responses to pathogen-associated molecular pattern and damage-associated molecular pattern recognition by the innate immune system, and how this may influence adaptive immunity. A well-characterized post-translational consequence of pattern recognition receptor signaling is the assembly of a multimeric signaling platform, termed the inflammasome, by members of the nucleotide-binding oligomerization domain (Nod), leucine-rich repeat-containing receptors (NLRs), and pyrin and HIN domain (PYHIN) families. Inflammasomes assemble in response to cytosolic perturbations, such as mitochondrial dysfunction and aberrant ion fluxes in the case of the canonical NLRP3 inflammasome or the presence of bacterial lipopolysaccharides in the case of the non-canonical inflammasome. Assembly of the inflammasome allows for the cleavage and activation of inflammatory caspases. These activated inflammatory caspases in turn cleave pro-form inflammatory cytokines into their mature bioactive species and lead to unconventional protein secretion and lytic cell death. In this review, we discuss evidence for inflammasome-mediated instruction and contextualization of infectious and sterile agents to the adaptive immune system.
Collapse
|
88
|
Liu W, Liu X, Li Y, Zhao J, Liu Z, Hu Z, Wang Y, Yao Y, Miller AW, Su B, Cookson MR, Li X, Kang Z. LRRK2 promotes the activation of NLRC4 inflammasome during Salmonella Typhimurium infection. J Exp Med 2017; 214:3051-3066. [PMID: 28821568 PMCID: PMC5626397 DOI: 10.1084/jem.20170014] [Citation(s) in RCA: 104] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 05/20/2017] [Accepted: 07/11/2017] [Indexed: 12/26/2022] Open
Abstract
LRRK2 is a serine/threonine protein kinase previously implicated in immunity against intracellular pathogens. In this study, Liu et al. report that LRRK2 promotes the host defense against Salmonella Typhimurium infection by phosphorylating NLRC4 at Ser533, thereby promoting the activation of NLRC4 inflammasome. Although genetic polymorphisms in the LRRK2 gene are associated with a variety of diseases, the physiological function of LRRK2 remains poorly understood. In this study, we report a crucial role for LRRK2 in the activation of the NLRC4 inflammasome during host defense against Salmonella enteric serovar Typhimurium infection. LRRK2 deficiency reduced caspase-1 activation and IL-1β secretion in response to NLRC4 inflammasome activators in macrophages. Lrrk2−/− mice exhibited impaired clearance of pathogens after acute S. Typhimurium infection. Mechanistically, LRRK2 formed a complex with NLRC4 in the macrophages, and the formation of the LRRK2–NLRC4 complex led to the phosphorylation of NLRC4 at Ser533. Importantly, the kinase activity of LRRK2 is required for optimal NLRC4 inflammasome activation. Collectively, our study reveals an important role for LRRK2 in the host defense by promoting NLRC4 inflammasome activation.
Collapse
Affiliation(s)
- Weiwei Liu
- Shanghai Institute of Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xia'nan Liu
- Shanghai Institute of Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yu Li
- Shanghai Institute of Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Junjie Zhao
- Department of Immunology, Cleveland Clinic, Cleveland, OH
| | - Zhenshan Liu
- Shanghai Institute of Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zhuqin Hu
- Shanghai Institute of Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ying Wang
- Shanghai Institute of Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yufeng Yao
- Department of Immunology and Microbiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Aaron W Miller
- Department of Immunology, Cleveland Clinic, Cleveland, OH.,Department of Urology, Cleveland Clinic, Cleveland, OH
| | - Bing Su
- Shanghai Institute of Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Mark R Cookson
- Cell Biology and Gene Expression Section, Laboratory of Neurogenetics, National Institute on Aging, Bethesda, MD
| | - Xiaoxia Li
- Department of Immunology, Cleveland Clinic, Cleveland, OH .,Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, OH
| | - Zizhen Kang
- Shanghai Institute of Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai, China .,Department of Immunology, Cleveland Clinic, Cleveland, OH.,Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, OH
| |
Collapse
|
89
|
Mascarenhas DPA, Cerqueira DM, Pereira MSF, Castanheira FVS, Fernandes TD, Manin GZ, Cunha LD, Zamboni DS. Inhibition of caspase-1 or gasdermin-D enable caspase-8 activation in the Naip5/NLRC4/ASC inflammasome. PLoS Pathog 2017; 13:e1006502. [PMID: 28771586 PMCID: PMC5542441 DOI: 10.1371/journal.ppat.1006502] [Citation(s) in RCA: 109] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 06/30/2017] [Indexed: 11/19/2022] Open
Abstract
Legionella pneumophila is a Gram-negative, flagellated bacterium that survives in phagocytes and causes Legionnaires’ disease. Upon infection of mammalian macrophages, cytosolic flagellin triggers the activation of Naip/NLRC4 inflammasome, which culminates in pyroptosis and restriction of bacterial replication. Although NLRC4 and caspase-1 participate in the same inflammasome, Nlrc4-/- mice and their macrophages are more permissive to L. pneumophila replication compared with Casp1/11-/-. This feature supports the existence of a pathway that is NLRC4-dependent and caspase-1/11-independent. Here, we demonstrate that caspase-8 is recruited to the Naip5/NLRC4/ASC inflammasome in response to flagellin-positive bacteria. Accordingly, caspase-8 is activated in Casp1/11-/- macrophages in a process dependent on flagellin, Naip5, NLRC4 and ASC. Silencing caspase-8 in Casp1/11-/- cells culminated in macrophages that were as susceptible as Nlrc4-/- for the restriction of L. pneumophila replication. Accordingly, macrophages and mice deficient in Asc/Casp1/11-/- were more susceptible than Casp1/11-/- and as susceptible as Nlrc4-/- for the restriction of infection. Mechanistically, we found that caspase-8 activation triggers gasdermin-D-independent pore formation and cell death. Interestingly, caspase-8 is recruited to the Naip5/NLRC4/ASC inflammasome in wild-type macrophages, but it is only activated when caspase-1 or gasdermin-D is inhibited. Our data suggest that caspase-8 activation in the Naip5/NLRC4/ASC inflammasome enable induction of cell death when caspase-1 or gasdermin-D is suppressed. Legionella pneumophila is the causative agent of Legionnaires’ disease, an atypical pneumophila that affects people worldwide. Besides the clinical importance, L. pneumophila is a very useful model of pathogenic bacteria for investigation of the interactions of innate immune cells with bacterial pathogens. Studies using L. pneumophila demonstrated that Naip5 and NLRC4 activate caspase-1 and this inflammasome is activated by bacterial flagellin. However, macrophages and mice deficient in NLRC4 are more susceptible for L. pneumophila replication than those deficient in caspase-1, indicating that the flagellin/Naip5/NLRC4 inflammasome triggers responses that are independent on caspase-1. Here, we used L. pneumophila to investigate this novel pathway and found that caspase-8 interacts with NLRC4 in a process that is dependent on ASC and independent of caspase-1 and caspase-11. Although caspase-8 is recruited to the Naip5/NLRC4/ASC inflammasome, it is only activated when caspase-1 or gasdermin-D is inhibited. Our data suggest that caspase-8 activation in the Naip5/NLRC4/ASC inflammasome may favor host responses during infections against pathogens that inhibit components of the pyroptotic cell death including caspase-1 and gasdermin-D.
Collapse
Affiliation(s)
- Danielle P. A. Mascarenhas
- Department of Cell Biology, School of Medicine of Ribeirão Preto, University of São Paulo. Ribeirão Preto, Brazil
| | - Daiane M. Cerqueira
- Department of Cell Biology, School of Medicine of Ribeirão Preto, University of São Paulo. Ribeirão Preto, Brazil
| | - Marcelo S. F. Pereira
- Department of Cell Biology, School of Medicine of Ribeirão Preto, University of São Paulo. Ribeirão Preto, Brazil
| | - Fernanda V. S. Castanheira
- Department of Cell Biology, School of Medicine of Ribeirão Preto, University of São Paulo. Ribeirão Preto, Brazil
| | - Talita D. Fernandes
- Department of Cell Biology, School of Medicine of Ribeirão Preto, University of São Paulo. Ribeirão Preto, Brazil
| | - Graziele Z. Manin
- Department of Cell Biology, School of Medicine of Ribeirão Preto, University of São Paulo. Ribeirão Preto, Brazil
| | - Larissa D. Cunha
- Department of Cell Biology, School of Medicine of Ribeirão Preto, University of São Paulo. Ribeirão Preto, Brazil
| | - Dario S. Zamboni
- Department of Cell Biology, School of Medicine of Ribeirão Preto, University of São Paulo. Ribeirão Preto, Brazil
- * E-mail:
| |
Collapse
|
90
|
Abstract
The inflammasome is a large multimeric protein complex comprising an effector protein that demonstrates specificity for a variety of activators or ligands; an adaptor molecule; and procaspase-1, which is converted to caspase-1 upon inflammasome activation. Inflammasomes are expressed primarily by myeloid cells and are located within the cell. The macromolecular inflammasome structure can be visualized by cryo-electron microscopy. This complex has been found to play a role in a variety of disease models in mice, and several have been genetically linked to human diseases. In most cases, the effector protein is a member of the NLR (nucleotide-binding domain leucine-rich repeat-containing) or NOD (nucleotide oligomerization domain)-like receptor protein family. However, other effectors have also been described, with the most notable being AIM-2 (absent in melanoma 2), which recognizes DNA to elicit inflammasome function. This review will focus on the role of the inflammasome in myeloid cells and its role in health and disease.
Collapse
|
91
|
Takagi M, Takakubo Y, Pajarinen J, Naganuma Y, Oki H, Maruyama M, Goodman SB. Danger of frustrated sensors: Role of Toll-like receptors and NOD-like receptors in aseptic and septic inflammations around total hip replacements. J Orthop Translat 2017; 10:68-85. [PMID: 29130033 PMCID: PMC5676564 DOI: 10.1016/j.jot.2017.05.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The innate immune sensors, Toll-like receptors (TLRs) and nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs), can recognize not only exogenous pathogen-associated molecular patterns (PAMPs), but also endogenous molecules created upon tissue injury, sterile inflammation, and degeneration. Endogenous ligands are called damage-associated molecular patterns (DAMPs), and include endogenous molecules released from activated and necrotic cells as well as damaged extracellular matrix. TLRs and NLRs can interact with various ligands derived from PAMPs and DAMPs, leading to activation and/or modulation of intracellular signalling pathways. Intensive research on the innate immune sensors, TLRs and NLRs, has brought new insights into the pathogenesis of not only various infectious and rheumatic diseases, but also aseptic foreign body granuloma and septic inflammation of failed total hip replacements (THRs). In this review, recent knowledge is summarized on the innate immune system, including TLRs and NLRs and their danger signals, with special reference to their possible role in the adverse local host response to THRs. Translational potential of this article: A clear understanding of the roles of Toll-like receptors and NOD-like receptors in aseptic and septic loosening of joint replacements will facilitate potential strategies to mitigate these events, thereby extending the longevity of implants in humans.
Collapse
Affiliation(s)
- Michiaki Takagi
- Department of Orthopaedic Surgery, Yamagata University Faculty of Medicine, Yamagata City, Yamagata, Japan
| | - Yuya Takakubo
- Department of Orthopaedic Surgery, Yamagata University Faculty of Medicine, Yamagata City, Yamagata, Japan
| | - Jukka Pajarinen
- Department of Orthopaedic Surgery, Stanford University, Stanford, CA, USA
| | - Yasushi Naganuma
- Department of Orthopaedic Surgery, Yamagata University Faculty of Medicine, Yamagata City, Yamagata, Japan
| | - Hiroharu Oki
- Department of Orthopaedic Surgery, Yamagata University Faculty of Medicine, Yamagata City, Yamagata, Japan
| | - Masahiro Maruyama
- Department of Orthopaedic Surgery, Yamagata University Faculty of Medicine, Yamagata City, Yamagata, Japan.,Department of Orthopaedic Surgery, Stanford University, Stanford, CA, USA
| | - Stuart B Goodman
- Department of Orthopaedic Surgery, Stanford University, Stanford, CA, USA
| |
Collapse
|
92
|
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
|
93
|
Freeman L, Guo H, David CN, Brickey WJ, Jha S, Ting JPY. NLR members NLRC4 and NLRP3 mediate sterile inflammasome activation in microglia and astrocytes. J Exp Med 2017; 214:1351-1370. [PMID: 28404595 PMCID: PMC5413320 DOI: 10.1084/jem.20150237] [Citation(s) in RCA: 255] [Impact Index Per Article: 36.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 12/26/2016] [Accepted: 02/28/2017] [Indexed: 12/31/2022] Open
Abstract
Lysophosphatidylcholine is associated with neurodegeneration and demyelination. Freeman et al. demonstrate that lysophosphatidylcholine triggers NLRP3- and NLRC4-dependent inflammasome activation, and in a synergistic fashion, NLRP3 and NLRC4 contribute to a cuprizone-induced demyelination model in vivo. Inflammation in the brain accompanies several high-impact neurological diseases including multiple sclerosis (MS), stroke, and Alzheimer’s disease. Neuroinflammation is sterile, as damage-associated molecular patterns rather than microbial pathogens elicit the response. The inflammasome, which leads to caspase-1 activation, is implicated in neuroinflammation. In this study, we reveal that lysophosphatidylcholine (LPC), a molecule associated with neurodegeneration and demyelination, elicits NLRP3 and NLRC4 inflammasome activation in microglia and astrocytes, which are central players in neuroinflammation. LPC-activated inflammasome also requires ASC (apoptotic speck containing protein with a CARD), caspase-1, cathepsin-mediated degradation, calcium mobilization, and potassium efflux but not caspase-11. To study the physiological relevance, Nlrc4−/− and Nlrp3−/− mice are studied in the cuprizone model of neuroinflammation and demyelination. Mice lacking both genes show the most pronounced reduction in astrogliosis and microglial accumulation accompanied by decreased expression of the LPC receptor G2A, whereas MS patient samples show increased G2A. These results reveal that NLRC4 and NLRP3, which normally form distinct inflammasomes, activate an LPC-induced inflammasome and are important in astrogliosis and microgliosis.
Collapse
Affiliation(s)
- Leslie Freeman
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599.,Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Haitao Guo
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Clément N David
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - W June Brickey
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Sushmita Jha
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 .,Indian Institute of Technology Jodhpur, Rajasthan 342011, India
| | - Jenny P-Y Ting
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 .,Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599.,Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599.,Department of Microbiology and Immunology, Institute of Inflammatory Diseases, Center for Translational Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| |
Collapse
|
94
|
Differential roles of caspase-1 and caspase-11 in infection and inflammation. Sci Rep 2017; 7:45126. [PMID: 28345580 PMCID: PMC5366862 DOI: 10.1038/srep45126] [Citation(s) in RCA: 96] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 02/16/2017] [Indexed: 02/07/2023] Open
Abstract
Caspase-1, also known as interleukin-1β (IL-1β)-converting enzyme (ICE), regulates antimicrobial host defense, tissue repair, tumorigenesis, metabolism and membrane biogenesis. On activation within an inflammasome complex, caspase-1 induces pyroptosis and converts pro-IL-1β and pro-IL-18 into their biologically active forms. “ICE−/−” or “Casp1−/−” mice generated using 129 embryonic stem cells carry a 129-associated inactivating passenger mutation on the caspase-11 locus, essentially making them deficient in both caspase-1 and caspase-11. The overlapping and unique functions of caspase-1 and caspase-11 are difficult to unravel without additional genetic tools. Here, we generated caspase-1–deficient mouse (Casp1Null) on the C57BL/6 J background that expressed caspase-11. Casp1Null cells did not release IL-1β and IL-18 in response to NLRC4 activators Salmonella Typhimurium and flagellin, canonical or non-canonical NLRP3 activators LPS and ATP, Escherichia coli, Citrobacter rodentium and transfection of LPS, AIM2 activators Francisella novicida, mouse cytomegalovirus and DNA, and the infectious agents Listeria monocytogenes and Aspergillus fumigatus. We further demonstrated that caspase-1 and caspase-11 differentially contributed to the host defense against A. fumigatus infection and to endotoxemia.
Collapse
|
95
|
Bacterial secretion system skews the fate of Legionella-containing vacuoles towards LC3-associated phagocytosis. Sci Rep 2017; 7:44795. [PMID: 28317932 PMCID: PMC5357938 DOI: 10.1038/srep44795] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 02/14/2017] [Indexed: 01/17/2023] Open
Abstract
The evolutionarily conserved processes of endosome-lysosome maturation and macroautophagy are established mechanisms that limit survival of intracellular bacteria. Similarly, another emerging mechanism is LC3-associated phagocytosis (LAP). Here we report that an intracellular vacuolar pathogen, Legionella dumoffii, is specifically targeted by LAP over classical endocytic maturation and macroautophagy pathways. Upon infection, the majority of L. dumoffii resides in ER-like vacuoles and replicate within this niche, which involves inhibition of classical endosomal maturation. The establishment of the replicative niche requires the bacterial Dot/Icm type IV secretion system (T4SS). Intriguingly, the remaining subset of L. dumoffii transiently acquires LC3 to L. dumoffii-containing vacuoles in a Dot/Icm T4SS-dependent manner. The LC3-decorated vacuoles are bound by an apparently undamaged single membrane, and fail to associate with the molecules implicated in selective autophagy, such as ubiquitin or adaptors. The process requires toll-like receptor 2, Rubicon, diacylglycerol signaling and downstream NADPH oxidases, whereas ULK1 kinase is dispensable. Together, we have discovered an intracellular pathogen, the survival of which in infected cells is limited predominantly by LAP. The results suggest that L. dumoffii is a valuable model organism for examining the mechanistic details of LAP, particularly induced by bacterial infection.
Collapse
|
96
|
Lin C, Zhang J. Inflammasomes in Inflammation-Induced Cancer. Front Immunol 2017; 8:271. [PMID: 28360909 PMCID: PMC5350111 DOI: 10.3389/fimmu.2017.00271] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Accepted: 02/24/2017] [Indexed: 12/19/2022] Open
Abstract
The inflammasome is an important multiprotein complex that functions during inflammatory immune responses. The activation of inflammasome will lead to the autoactivation of caspase-1 and subsequent cleavage of proIL-1β and proIL-18, which are key sources of inflammatory manifestations. Recently, the roles of inflammasomes in cancers have been extensively explored, especially in inflammation-induced cancers. In different and specific contexts, inflammasomes exhibit distinct and even contrasting effects in cancer development. In some cases, inflammasomes initiate carcinogenesis through the extrinsic pathway and maintain the malignant cancer microenvironment through the intrinsic pathway. On the contrary, inflammasomes also exert anticancer effects by specialized programmed cell death called pyroptosis and immune regulatory functions. The phases and compartments in which inflammasomes are activated strongly influence the final immune effects. We systemically summarize the functions of inflammasomes in inflammation-induced cancers, especially in gastrointestinal and skin cancers. Besides, information about the current therapeutic use of inflammasome-related products and potential future developing directions are also introduced.
Collapse
Affiliation(s)
- Chu Lin
- Department of Immunology, School of Basic Medical Sciences, Key Laboratory of Medical Immunology, National Health and Family Planning Commission of the People's Republic of China, Peking University Health Science Center , Beijing , China
| | - Jun Zhang
- Department of Immunology, School of Basic Medical Sciences, Key Laboratory of Medical Immunology, National Health and Family Planning Commission of the People's Republic of China, Peking University Health Science Center , Beijing , China
| |
Collapse
|
97
|
Abstract
Caspase-1 is an integral regulator of the innate immune system. Its core functions are the processing and secretion of the proinflammatory cytokines interleukin 1β (IL-1 beta) and IL-18 and the initiation of proinflammatory cell death, which is referred to as pyroptosis. Activation of caspase-1 plays a pivotal role during immune defense mechanisms against infections by the innate immune system. Dysregulated activation of caspase-1 has been recognized to be involved in the pathophysiology of a constantly increasing number of inflammatory diseases. This article gives an overview of the regulation and function of caspase-1 and its involvement in monogenic, polygenic and/or polyetiological rheumatic diseases.
Collapse
Affiliation(s)
- S Winkler
- Klinik und Poliklinik für Kinder- und Jugendmedizin, Universitätsklinikum Carl Gustav Carus, Technische Universität Dresden, Fetscherstr. 74, 01307, Dresden, Deutschland.
| | - C M Hedrich
- Klinik und Poliklinik für Kinder- und Jugendmedizin, Universitätsklinikum Carl Gustav Carus, Technische Universität Dresden, Fetscherstr. 74, 01307, Dresden, Deutschland
| | - A Rösen-Wolff
- Klinik und Poliklinik für Kinder- und Jugendmedizin, Universitätsklinikum Carl Gustav Carus, Technische Universität Dresden, Fetscherstr. 74, 01307, Dresden, Deutschland
| |
Collapse
|
98
|
Park B, Park G, Kim J, Lim SA, Lee KM. Innate immunity against Legionella pneumophila during pulmonary infections in mice. Arch Pharm Res 2017; 40:131-145. [PMID: 28063015 DOI: 10.1007/s12272-016-0859-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 11/02/2016] [Indexed: 01/01/2023]
Abstract
Legionella pneumophila is an etiological agent of the severe pneumonia known as Legionnaires' disease (LD). This gram-negative bacterium is thought to replicate naturally in various freshwater amoebae, but also replicates in human alveolar macrophages. Inside host cells, legionella induce the production of non-endosomal replicative phagosomes by injecting effector proteins into the cytosol. Innate immune responses are first line defenses against legionella during early phases of infection, and distinguish between legionella and host cells using germline-encoded pattern recognition receptors such as Toll-like receptors , NOD-like receptors, and RIG-I-like receptors, which sense pathogen-associated molecular patterns that are absent in host cells. During pulmonary legionella infections, various inflammatory cells such as macrophages, neutrophils, natural killer (NK) cells, large mononuclear cells, B cells, and CD4+ and CD8+ T cells are recruited into infected lungs, and predominantly occupy interstitial areas to control legionella. During pulmonary legionella infections, the interplay between distinct cytokines and chemokines also modulates innate host responses to clear legionella from the lungs. Recognition by NK cell receptors triggers effector functions including secretion of cytokines and chemokines, and leads to lysis of target cells. Crosstalk between NK cells and dendritic cells, monocytes, and macrophages provides a major first-line defense against legionella infection, whereas activation of T and B cells resolves the infection and mounts legionella-specific memory in the host.
Collapse
Affiliation(s)
- Bonggoo Park
- Global Research Laboratory, Department of Biochemistry and Molecular Biology, Korea University College of Medicine, 126-1 Anam-dong 5-ga, Seongbuk-gu, Seoul, 136-713, Korea
| | - Gayoung Park
- Global Research Laboratory, Department of Biochemistry and Molecular Biology, Korea University College of Medicine, 126-1 Anam-dong 5-ga, Seongbuk-gu, Seoul, 136-713, Korea.,Department of Biomicrosystem Technology, Korea University, Seoul, 136-701, Korea
| | - Jiyoung Kim
- Global Research Laboratory, Department of Biochemistry and Molecular Biology, Korea University College of Medicine, 126-1 Anam-dong 5-ga, Seongbuk-gu, Seoul, 136-713, Korea
| | - Seon Ah Lim
- Global Research Laboratory, Department of Biochemistry and Molecular Biology, Korea University College of Medicine, 126-1 Anam-dong 5-ga, Seongbuk-gu, Seoul, 136-713, Korea
| | - Kyung-Mi Lee
- Global Research Laboratory, Department of Biochemistry and Molecular Biology, Korea University College of Medicine, 126-1 Anam-dong 5-ga, Seongbuk-gu, Seoul, 136-713, Korea.
| |
Collapse
|
99
|
Kong X, Yuan Z, Cheng J. The function of NOD-like receptors in central nervous system diseases. J Neurosci Res 2016; 95:1565-1573. [PMID: 28029680 DOI: 10.1002/jnr.24004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 11/11/2016] [Accepted: 11/28/2016] [Indexed: 12/17/2022]
Abstract
NOD-like receptors (NLRs) are critical cytoplasmic pattern-recognition receptors (PRRs) that play an important role in the host innate immune response and immunity homeostasis. There is a growing body of evidence that NLRs are involved in a wide range of inflammatory diseases, including cancer, metabolic diseases, and autoimmune disorders. Recent studies have indicated that the proteins of the NLR family are linked with the pathophysiology of neurodegenerative diseases, including Alzheimer's disease (AD), Parkinson's disease (PD), and multiple sclerosis (MS), and psychological diseases. In this review, we mainly focus on the role of NLRs and the underlying signaling pathways in central nervous system (CNS) diseases. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Xiangxi Kong
- The State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.,School of Basic Medical Science, Lanzhou University, Lanzhou, 730000, Gansu Province, China
| | - Zengqiang Yuan
- The State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.,Center of Alzheimer's Disease, Beijing Institute for Brain Disorders, Beijing, 100069, China
| | - Jinbo Cheng
- The State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.,Center of Alzheimer's Disease, Beijing Institute for Brain Disorders, Beijing, 100069, China
| |
Collapse
|
100
|
Growth inhibition of cytosolic Salmonella by caspase-1 and caspase-11 precedes host cell death. Nat Commun 2016; 7:13292. [PMID: 27808091 PMCID: PMC5097160 DOI: 10.1038/ncomms13292] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 09/19/2016] [Indexed: 02/07/2023] Open
Abstract
Sensing bacterial products in the cytosol of mammalian cells by NOD-like receptors leads to the activation of caspase-1 inflammasomes, and the production of the pro-inflammatory cytokines interleukin (IL)-18 and IL-1β. In addition, mouse caspase-11 (represented in humans by its orthologs, caspase-4 and caspase-5) detects cytosolic bacterial LPS directly. Activation of caspase-1 and caspase-11 initiates pyroptotic host cell death that releases potentially harmful bacteria from the nutrient-rich host cell cytosol into the extracellular environment. Here we use single cell analysis and time-lapse microscopy to identify a subpopulation of host cells, in which growth of cytosolic Salmonella Typhimurium is inhibited independently or prior to the onset of cell death. The enzymatic activities of caspase-1 and caspase-11 are required for growth inhibition in different cell types. Our results reveal that these proteases have important functions beyond the direct induction of pyroptosis and proinflammatory cytokine secretion in the control of growth and elimination of cytosolic bacteria. Inflammatory caspases restrict microbial growth by inducing cytokine production and pyroptosis, but other caspase-induced mechanisms are thought to contribute. Here the authors use time-lapse microscopy of single cells to show that caspase1/11 has anti-Salmonella functions that occur in advance of cell death induction.
Collapse
|