1
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Wang J, He W, Li C, Ma Y, Liu M, Ye J, Sun L, Su J, Zhou L. Focus on negatively regulated NLRs in inflammation and cancer. Int Immunopharmacol 2024; 136:112347. [PMID: 38820966 DOI: 10.1016/j.intimp.2024.112347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2024] [Revised: 05/15/2024] [Accepted: 05/24/2024] [Indexed: 06/02/2024]
Abstract
Nucleotide-binding and oligomerization structural domain (NOD)-like receptors (NLRs) play an important role in innate immunity as cytoplasmic pattern recognition receptors (PRRs). Over the past decade, considerable progress has been made in understanding the mechanisms by which NLR family members regulate immune system function, particularly the formation of inflammasome and downstream inflammatory signals. However, recent studies have shown that some members of the NLRs, including Nlrp12, NLRX1, and NLRC3, are important in the negative regulation of inflammatory signaling and are involved in the development of various diseases, including inflammatory diseases and cancer. Based on this, in this review, we first summarize the interactions between canonical and non-canonical nuclear factor-κB (NF-κB) signaling pathways that are mainly involved in NLRs, then highlight the mechanisms by which the above NLRs negatively regulate inflammatory signaling responses as well as their roles in tumor progression, and finally summarize the synthetic and natural derivatives with therapeutic effects on these NLRs, which are considered as potential therapeutic agents for overcoming inflammatory diseases.
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Affiliation(s)
- Jian Wang
- Department of Pathology, Affiliated Hospital of Changchun University of Chinese Medicine, Changchun 130012, China; Key Laboratory of Pathobiology, Department of Pathophysiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun 130012, China
| | - Wenjing He
- Medical Intensive Care Unit, Affiliated Hospital of Changchun University of Chinese Medicine, Changchun 130012, China
| | - Chunhua Li
- Department of Endocrinology, Affiliated Hospital of Changchun University of Chinese Medicine, Changchun 130012, China
| | - Yue Ma
- Department of Pathology, Affiliated Hospital of Changchun University of Chinese Medicine, Changchun 130012, China
| | - Mingjun Liu
- Department of Pathology, Affiliated Hospital of Changchun University of Chinese Medicine, Changchun 130012, China
| | - Jinxiang Ye
- Department of Pathology, Affiliated Hospital of Changchun University of Chinese Medicine, Changchun 130012, China
| | - Lei Sun
- Changchun Tongyuan Hospital, Changchun 130012, China
| | - Jing Su
- Key Laboratory of Pathobiology, Department of Pathophysiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun 130012, China
| | - Lei Zhou
- Department of Pathology, Affiliated Hospital of Changchun University of Chinese Medicine, Changchun 130012, China.
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2
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Jastrab JB, Kagan JC. Strategies of bacterial detection by inflammasomes. Cell Chem Biol 2024; 31:835-850. [PMID: 38636521 PMCID: PMC11103797 DOI: 10.1016/j.chembiol.2024.03.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 03/09/2024] [Accepted: 03/26/2024] [Indexed: 04/20/2024]
Abstract
Mammalian innate immunity is regulated by pattern-recognition receptors (PRRs) and guard proteins, which use distinct strategies to detect infections. PRRs detect bacterial molecules directly, whereas guards detect host cell manipulations by microbial virulence factors. Despite sensing infection through different mechanisms, both classes of innate immune sensors can activate the inflammasome, an immune complex that can mediate cell death and inflammation. Inflammasome-mediated immune responses are crucial for host defense against many bacterial pathogens and prevent invasion by non-pathogenic organisms. In this review, we discuss the mechanisms by which inflammasomes are stimulated by PRRs and guards during bacterial infection, and the strategies used by virulent bacteria to evade inflammasome-mediated immunity.
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Affiliation(s)
- Jordan B Jastrab
- Division of Gastroenterology, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA; Division of Infectious Diseases, Brigham and Women's Hospital, Boston, MA 02115, USA
| | - Jonathan C Kagan
- Division of Gastroenterology, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA.
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3
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Ernst C, Andreassen PR, Giger GH, Nguyen BD, Gäbelein CG, Guillaume-Gentil O, Fattinger SA, Sellin ME, Hardt WD, Vorholt JA. Direct Salmonella injection into enteroid cells allows the study of host-pathogen interactions in the cytosol with high spatiotemporal resolution. PLoS Biol 2024; 22:e3002597. [PMID: 38684033 PMCID: PMC11057982 DOI: 10.1371/journal.pbio.3002597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 03/21/2024] [Indexed: 05/02/2024] Open
Abstract
Intestinal epithelial cells (IECs) play pivotal roles in nutrient uptake and in the protection against gut microorganisms. However, certain enteric pathogens, such as Salmonella enterica serovar Typhimurium (S. Tm), can invade IECs by employing flagella and type III secretion systems (T3SSs) with cognate effector proteins and exploit IECs as a replicative niche. Detection of flagella or T3SS proteins by IECs results in rapid host cell responses, i.e., the activation of inflammasomes. Here, we introduce a single-cell manipulation technology based on fluidic force microscopy (FluidFM) that enables direct bacteria delivery into the cytosol of single IECs within a murine enteroid monolayer. This approach allows to specifically study pathogen-host cell interactions in the cytosol uncoupled from preceding events such as docking, initiation of uptake, or vacuole escape. Consistent with current understanding, we show using a live-cell inflammasome reporter that exposure of the IEC cytosol to S. Tm induces NAIP/NLRC4 inflammasomes via its known ligands flagellin and T3SS rod and needle. Injected S. Tm mutants devoid of these invasion-relevant ligands were able to grow in the cytosol of IECs despite the absence of T3SS functions, suggesting that, in the absence of NAIP/NLRC4 inflammasome activation and the ensuing cell death, no effector-mediated host cell manipulation is required to render the epithelial cytosol growth-permissive for S. Tm. Overall, the experimental system to introduce S. Tm into single enteroid cells enables investigations into the molecular basis governing host-pathogen interactions in the cytosol with high spatiotemporal resolution.
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Affiliation(s)
- Chantal Ernst
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland
| | | | - Gabriel H. Giger
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Bidong D. Nguyen
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland
| | | | | | - Stefan A. Fattinger
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Mikael E. Sellin
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Wolf-Dietrich Hardt
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Julia A. Vorholt
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland
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4
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Matico RE, Yu X, Miller R, Somani S, Ricketts MD, Kumar N, Steele RA, Medley Q, Berger S, Faustin B, Sharma S. Structural basis of the human NAIP/NLRC4 inflammasome assembly and pathogen sensing. Nat Struct Mol Biol 2024; 31:82-91. [PMID: 38177670 PMCID: PMC10803261 DOI: 10.1038/s41594-023-01143-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Accepted: 09/28/2023] [Indexed: 01/06/2024]
Abstract
The NLR family caspase activation and recruitment domain-containing 4 (NLRC4) inflammasome is a critical cytosolic innate immune machine formed upon the direct sensing of bacterial infection and in response to cell stress during sterile chronic inflammation. Despite its major role in instigating the subsequent host immune response, a more complete understanding of the molecular events in the formation of the NLRC4 inflammasome in humans is lacking. Here we identify Bacillus thailandensis type III secretion system needle protein (Needle) as a potent trigger of the human NLR family apoptosis inhibitory protein (NAIP)/NLRC4 inflammasome complex formation and determine its structural features by cryogenic electron microscopy. We also provide a detailed understanding of how type III secretion system pathogen components are sensed by human NAIP to form a cascade of NLRC4 protomer through a critical lasso-like motif, a 'lock-key' activation model and large structural rearrangement, ultimately forming the full human NLRC4 inflammasome. These results shed light on key regulatory mechanisms specific to the NLRC4 inflammasome assembly, and the innate immune modalities of pathogen sensing in humans.
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Affiliation(s)
- Rosalie E Matico
- Structural and Protein Sciences, Johnson & Johnson Innovative Medicine, Spring House, PA, USA
| | - Xiaodi Yu
- Structural and Protein Sciences, Johnson & Johnson Innovative Medicine, Spring House, PA, USA.
| | - Robyn Miller
- Structural and Protein Sciences, Johnson & Johnson Innovative Medicine, Spring House, PA, USA
| | - Sandeep Somani
- In Silico Discovery Sciences, Johnson & Johnson Innovative Medicine, Spring House, PA, USA
| | - M Daniel Ricketts
- Structural and Protein Sciences, Johnson & Johnson Innovative Medicine, Spring House, PA, USA
| | - Nikit Kumar
- Structural and Protein Sciences, Johnson & Johnson Innovative Medicine, Spring House, PA, USA
| | - Ruth A Steele
- Structural and Protein Sciences, Johnson & Johnson Innovative Medicine, Spring House, PA, USA
| | - Quintus Medley
- Discovery Immunology, Johnson & Johnson Innovative Medicine, Cambridge, MA, USA
| | - Scott Berger
- Discovery Immunology, Johnson & Johnson Innovative Medicine, Spring House, PA, USA
| | - Benjamin Faustin
- Discovery Immunology, Johnson & Johnson Innovative Medicine, San Diego, CA, USA
| | - Sujata Sharma
- Structural and Protein Sciences, Johnson & Johnson Innovative Medicine, Spring House, PA, USA
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5
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Paidimuddala B, Cao J, Zhang L. Structural basis for flagellin-induced NAIP5 activation. SCIENCE ADVANCES 2023; 9:eadi8539. [PMID: 38055825 PMCID: PMC10699770 DOI: 10.1126/sciadv.adi8539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Accepted: 11/06/2023] [Indexed: 12/08/2023]
Abstract
The NAIP (NLR family apoptosis inhibitory protein)/NLRC4 (NLR family CARD containing protein 4) inflammasome senses Gram-negative bacterial ligand. In the ligand-bound state, the winged helix domain of NAIP forms a steric clash with NLRC4 to open it up. However, how ligand binding activates NAIP is less clear. Here, we investigated the dynamics of the ligand-binding region of inactive NAIP5 and solved the cryo-EM structure of NAIP5 in complex with its specific ligand, FliC from flagellin, at 2.9-Å resolution. The structure revealed a "trap and lock" mechanism in FliC recognition, whereby FliC-D0C is first trapped by the hydrophobic pocket of NAIP5, then locked in the binding site by ID (insertion domain) and C-terminal tail of NAIP5. The FliC-D0N domain further inserts into ID to stabilize the complex. According to this mechanism, FliC triggers the conformational change of NAIP5 by bringing multiple flexible domains together.
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Affiliation(s)
- Bhaskar Paidimuddala
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, OR 97239, USA
| | - Jianhao Cao
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, OR 97239, USA
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6
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Zhang J, Brodsky IE, Shin S. Yersinia deploys type III-secreted effectors to evade caspase-4 inflammasome activation in human cells. mBio 2023; 14:e0131023. [PMID: 37615436 PMCID: PMC10653943 DOI: 10.1128/mbio.01310-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 07/06/2023] [Indexed: 08/25/2023] Open
Abstract
IMPORTANCE Yersinia are responsible for significant disease burden in humans, ranging from recurrent disease outbreaks (yersiniosis) to pandemics (Yersinia pestis plague). Together with rising antibiotic resistance rates, there is a critical need to better understand Yersinia pathogenesis and host immune mechanisms, as this information will aid in developing improved immunomodulatory therapeutics. Inflammasome responses in human cells are less studied relative to murine models of infection, though recent studies have uncovered key differences in inflammasome responses between mice and humans. Here, we dissect human intestinal epithelial cell and macrophage inflammasome responses to Yersinia pseudotuberculosis. Our findings provide insight into species- and cell type-specific differences in inflammasome responses to Yersinia.
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Affiliation(s)
- Jenna Zhang
- Department of Microbiology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Igor E. Brodsky
- Department of Pathobiology, University of Pennsylvania, School of Veterinary Medicine, Philadelphia, Pennsylvania, USA
| | - Sunny Shin
- Department of Microbiology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, Pennsylvania, USA
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7
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Pandeya A, Zhang Y, Cui J, Yang L, Li J, Zhang G, Wu C, Li Z, Wei Y. Inflammasome activation and pyroptosis mediate coagulopathy and inflammation in Salmonella systemic infection. Microbiol Res 2023; 275:127460. [PMID: 37467711 PMCID: PMC10693354 DOI: 10.1016/j.micres.2023.127460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2023] [Revised: 07/09/2023] [Accepted: 07/12/2023] [Indexed: 07/21/2023]
Abstract
Inflammasome activation is a critical defense mechanism against bacterial infection. Previous studies suggest that inflammasome activation protects against Salmonella oral infection. Here we find inflammasome activation plays a critical role in the pathogenesis of Salmonella systemic infection. We show that in a systemic infection model by i.p. injection of Salmonella, deficiency of caspase-1 or gasdermin-D prolonged survival time, reduced plasma concentrations of the proinflammatory cytokines IL-1β, IL-6 and TNFα. These deficiencies also protected against coagulopathy during Salmonella infection as evidenced by diminished prolongation of prothrombin time and increase in plasma thrombin-antithrombin complex concentrations in the caspase-1 or gasdermin-D deficient mice. Activation of the NAIP/NLRC4 inflammasome by flagellin and/or the components of the SPI1 type 3 secretion system played a critical role in Salmonella-induced coagulopathy. In the absence of flagellin and SPI1, the Salmonella mutant strain still triggered coagulopathy through the caspase-11/NLRP3 pathway. Our results reveal a previously undisclosed role of the inflammasomes and pyroptosis in the pathogenesis of Salmonella systemic infection.
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Affiliation(s)
- Ankit Pandeya
- Department of Pharmaceutical Sciences, Irma Lerma Rangel School of Pharmacy, Texas A&M University, College Station, TX, USA; Department of Chemistry, University of Kentucky, Lexington, KY, USA
| | - Yan Zhang
- Department of Pharmaceutical Sciences, Irma Lerma Rangel School of Pharmacy, Texas A&M University, College Station, TX, USA
| | - Jian Cui
- Saha Cardiovascular Research Center, College of Medicine, University of Kentucky, Lexington, KY, USA
| | - Ling Yang
- Department of Pharmaceutical Sciences, Irma Lerma Rangel School of Pharmacy, Texas A&M University, College Station, TX, USA
| | - Jeffery Li
- Department of Pharmaceutical Sciences, Irma Lerma Rangel School of Pharmacy, Texas A&M University, College Station, TX, USA
| | - Guoying Zhang
- Department of Pharmaceutical Sciences, Irma Lerma Rangel School of Pharmacy, Texas A&M University, College Station, TX, USA
| | - Congqing Wu
- Saha Cardiovascular Research Center, College of Medicine, University of Kentucky, Lexington, KY, USA; Department of Surgery, College of Medicine, University of Kentucky, Lexington, KY, USA; Department of Microbiology, Immunology, and Molecular Genetics, College of Medicine, University of Kentucky, Lexington, KY, USA
| | - Zhenyu Li
- Department of Pharmaceutical Sciences, Irma Lerma Rangel School of Pharmacy, Texas A&M University, College Station, TX, USA.
| | - Yinan Wei
- Department of Pharmaceutical Sciences, Irma Lerma Rangel School of Pharmacy, Texas A&M University, College Station, TX, USA.
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8
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Egan MS, O’Rourke EA, Mageswaran SK, Zuo B, Martynyuk I, Demissie T, Hunter EN, Bass AR, Chang YW, Brodsky IE, Shin S. Inflammasomes primarily restrict cytosolic Salmonella replication within human macrophages. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.17.549348. [PMID: 37503120 PMCID: PMC10370064 DOI: 10.1101/2023.07.17.549348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Salmonella enterica serovar Typhimurium is a facultative intracellular pathogen that utilizes its type III secretion systems (T3SSs) to inject virulence factors into the host cell and colonize the host. In turn, a subset of cytosolic immune receptors respond to T3SS ligands by forming multimeric signaling complexes called inflammasomes, which activate caspases that induce interleukin-1 (IL-1) family cytokine release and an inflammatory form of cell death called pyroptosis. Human macrophages mount a multifaceted inflammasome response to Salmonella infection that ultimately restricts intracellular bacterial replication. However, how inflammasomes restrict Salmonella replication remains unknown. We find that caspase-1 is essential for mediating inflammasome responses to Salmonella and subsequent restriction of bacterial replication within human macrophages, with caspase-4 contributing as well. We also demonstrate that the downstream pore-forming protein gasdermin D (GSDMD) and ninjurin-1 (NINJ1), a mediator of terminal cell lysis, play a role in controlling Salmonella replication in human macrophages. Notably, in the absence of inflammasome responses, we observed hyperreplication of Salmonella within the cytosol of infected cells, and we also observed increased bacterial replication within vacuoles, suggesting that inflammasomes control Salmonella replication primarily within the cytosol and also within vacuoles. These findings reveal that inflammatory caspases and pyroptotic factors mediate inflammasome responses that restrict the subcellular localization of intracellular Salmonella replication within human macrophages.
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Affiliation(s)
- Marisa S. Egan
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Emily A. O’Rourke
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Shrawan Kumar Mageswaran
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Biao Zuo
- Electron Microscopy Resource Laboratory, Department of Biochemistry & Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Inna Martynyuk
- Electron Microscopy Resource Laboratory, Department of Biochemistry & Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Tabitha Demissie
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Emma N. Hunter
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Antonia R. Bass
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Yi-Wei Chang
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Igor E. Brodsky
- Department of Pathobiology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA
| | - Sunny Shin
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
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9
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Zhang J, Brodsky IE, Shin S. Yersinia Type III-Secreted Effectors Evade the Caspase-4 Inflammasome in Human Cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.24.525473. [PMID: 36747770 PMCID: PMC9900831 DOI: 10.1101/2023.01.24.525473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Yersinia are gram-negative zoonotic bacteria that use a type III secretion system (T3SS) to inject Yersinia outer proteins (Yops) into the host cytosol to subvert essential components of innate immune signaling. However, Yersinia virulence activities can elicit activation of inflammasomes, which lead to inflammatory cell death and cytokine release to contain infection. Yersinia activation and evasion of inflammasomes have been characterized in murine macrophages but remain poorly defined in human cells, particularly intestinal epithelial cells (IECs), a primary site of intestinal Yersinia infection. In contrast to murine macrophages, we find that in both human IECs and macrophages, Yersinia pseudotuberculosis T3SS effectors enable evasion of the caspase-4 inflammasome, which senses cytosolic lipopolysaccharide (LPS). The antiphagocytic YopE and YopH, as well as the translocation regulator YopK, were collectively responsible for evading inflammasome activation, in part by inhibiting Yersinia internalization mediated by YadA and β1-integrin signaling. These data provide insight into the mechanisms of Yersinia-mediated inflammasome activation and evasion in human cells, and reveal species-specific differences underlying regulation of inflammasome responses to Yersinia .
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Affiliation(s)
- Jenna Zhang
- Department of Microbiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104
| | - Igor E. Brodsky
- Department of Pathobiology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, Pennsylvania 19104
| | - Sunny Shin
- Department of Microbiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104
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10
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Abstract
Investigation of fungal biology has been frequently motivated by the fact that many fungal species are important plant and animal pathogens. Such efforts have contributed significantly toward our understanding of fungal pathogenic lifestyles (virulence factors and strategies) and the interplay with host immune systems. In parallel, work on fungal allorecognition systems leading to the characterization of fungal regulated cell death determinants and pathways, has been instrumental for the emergent concept of fungal immunity. The uncovered evolutionary trans-kingdom parallels between fungal regulated cell death pathways and innate immune systems incite us to reflect further on the concept of a fungal immune system. Here, I briefly review key findings that have shaped the fungal immunity paradigm, providing a perspective on what I consider its most glaring knowledge gaps. Undertaking to fill such gaps would establish firmly the fungal immune system inside the broader field of comparative immunology.
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Affiliation(s)
- Asen Daskalov
- State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-products, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
- ImmunoConcEpT, CNRS UMR 5164, University of Bordeaux, Bordeaux, France
- Corresponding author
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11
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Paidimuddala B, Cao J, Zhang L. Structural basis for flagellin induced NAIP5 activation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.13.544801. [PMID: 37398004 PMCID: PMC10312664 DOI: 10.1101/2023.06.13.544801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
The NAIP/NLRC4 inflammasome is activated when NAIP binds to a gram-negative bacterial ligand. Initially, NAIP exists in an inactive state with a wide-open conformation. Upon ligand binding, the winged helix domain (WHD) of NAIP is activated and forms steric clash with NLRC4 to open it up. However, how ligand binding induces the conformational change of NAIP is less clear. To understand this process, we investigated the dynamics of the ligand binding region of inactive NAIP5 and solved the cryo-EM structure of NAIP5 in complex with its specific ligand, FliC from flagellin, at 2.93 Å resolution. The structure revealed a "trap and lock" mechanism in FliC recognition, whereby FliC-D0C is first trapped by the hydrophobic pocket of NAIP5, then locked in the binding site by the insertion domain (ID) and C-terminal tail (CTT) of NAIP5. The FliC-D0N domain further inserts into the loop of ID to stabilize the complex. According to this mechanism, FliC activates NAIP5 by bringing multiple flexible domains together, particularly the ID, HD2, and LRR domains, to form the active conformation and support the WHD loop in triggering NLRC4 activation.
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Affiliation(s)
- Bhaskar Paidimuddala
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, OR 97239, USA
| | - Jianhao Cao
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, OR 97239, USA
| | - Liman Zhang
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, OR 97239, USA
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12
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Egan MS, Zhang J, Shin S. Human and mouse NAIP/NLRC4 inflammasome responses to bacterial infection. Curr Opin Microbiol 2023; 73:102298. [PMID: 37058933 PMCID: PMC10225321 DOI: 10.1016/j.mib.2023.102298] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 02/15/2023] [Accepted: 02/22/2023] [Indexed: 04/16/2023]
Abstract
Intracellular immune complexes known as inflammasomes sense breaches of cytosolic sanctity. Inflammasomes promote downstream proinflammatory events, including interleukin-1 (IL-1) family cytokine release and pyroptotic cell death. The nucleotide-binding leucine-rich repeat family, apoptosis inhibitory protein/nucleotide-binding leucine-rich repeat family, caspase recruitment domain (CARD) domain-containing protein 4 (NAIP/NLRC4) inflammasome is involved in a range of pathogenic and protective inflammatory processes in mammalian hosts. In particular, the NAIP/NLRC4 inflammasome responds to flagellin and components of the virulence-associated type III secretion (T3SS) apparatus in the host cytosol, thereby allowing it to be a critical mediator of host defense during bacterial infection. Notable species- and cell type-specific differences exist in NAIP/NLRC4 inflammasome responses to bacterial pathogens. With a focus on Salmonella enterica serovar Typhimurium as a model pathogen, we review differences between murine and human NAIP/NLRC4 inflammasome responses. Differences in NAIP/NLRC4 inflammasome responses across species and cell types may have arisen in part due to evolutionary pressures.
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Affiliation(s)
- Marisa S Egan
- Department of Microbiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Jenna Zhang
- Department of Microbiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Sunny Shin
- Department of Microbiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.
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13
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Grayczyk JP, Egan MS, Liu L, Aunins E, Wynosky-Dolfi MA, Canna S, Minn AJ, Shin S, Brodsky IE. TLR priming licenses NAIP inflammasome activation by immunoevasive ligands. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.04.539437. [PMID: 37205371 PMCID: PMC10187295 DOI: 10.1101/2023.05.04.539437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
NLR family, apoptosis inhibitory proteins (NAIPs) detect bacterial flagellin and structurally related components of bacterial type III secretion systems (T3SS), and recruit NLR family, CARD domain containing protein 4 (NLRC4) and caspase-1 into an inflammasome complex that induces pyroptosis. NAIP/NLRC4 inflammasome assembly is initiated by the binding of a single NAIP to its cognate ligand, but a subset of bacterial flagellins or T3SS structural proteins are thought to evade NAIP/NLRC4 inflammasome sensing by not binding to their cognate NAIPs. Unlike other inflammasome components such as NLRP3, AIM2, or some NAIPs, NLRC4 is constitutively present in resting macrophages, and not thought to be regulated by inflammatory signals. Here, we demonstrate that Toll-like receptor (TLR) stimulation upregulates NLRC4 transcription and protein expression in murine macrophages, which licenses NAIP detection of evasive ligands. TLR-induced NLRC4 upregulation and NAIP detection of evasive ligands required p38 MAPK signaling. In contrast, TLR priming in human macrophages did not upregulate NLRC4 expression, and human macrophages remained unable to detect NAIP-evasive ligands even following priming. Critically, ectopic expression of either murine or human NLRC4 was sufficient to induce pyroptosis in response to immunoevasive NAIP ligands, indicating that increased levels of NLRC4 enable the NAIP/NLRC4 inflammasome to detect these normally evasive ligands. Altogether, our data reveal that TLR priming tunes the threshold for NAIP/NLRC4 inflammasome activation and enables inflammasome responses against immunoevasive or suboptimal NAIP ligands.
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Affiliation(s)
- James P Grayczyk
- Department of Pathobiology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA, USA
| | - Marisa S Egan
- Department of Microbiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Luying Liu
- Department of Pathobiology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA, USA
| | - Emily Aunins
- Department of Pathobiology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA, USA
| | - Meghan A Wynosky-Dolfi
- Department of Pathobiology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA, USA
| | - Scott Canna
- Department of Pediatrics, Division of Rheumatology, Children's Hospital of Philadelphia, Philadelphia, PA
| | - Andy J Minn
- Department of Radiation Oncology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
- Abramson Family Cancer Research Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
- Parker Institute for Cancer Immunotherapy, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
- Mark Foundation Center for Immunotherapy, Immune Signaling, and Radiation, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Sunny Shin
- Department of Microbiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Igor E Brodsky
- Department of Pathobiology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA, USA
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14
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Korkmaz FT, Traber KE. Innate immune responses in pneumonia. Pneumonia (Nathan) 2023; 15:4. [PMID: 36829255 PMCID: PMC9957695 DOI: 10.1186/s41479-023-00106-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 01/05/2023] [Indexed: 02/26/2023] Open
Abstract
The lungs are an immunologically unique environment; they are exposed to innumerable pathogens and particulate matter daily. Appropriate clearance of pathogens and response to pollutants is required to prevent overwhelming infection, while preventing tissue damage and maintaining efficient gas exchange. Broadly, the innate immune system is the collection of immediate, intrinsic immune responses to pathogen or tissue injury. In this review, we will examine the innate immune responses of the lung, with a particular focus on their role in pneumonia. We will discuss the anatomic barriers and antimicrobial proteins of the lung, pathogen and injury recognition, and the role of leukocytes (macrophages, neutrophils, and innate lymphocytes) and lung stromal cells in innate immunity. Throughout the review, we will focus on new findings in innate immunity as well as features that are unique to the lung.
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Affiliation(s)
- Filiz T Korkmaz
- Department of Medicine, Division of Immunology & Infectious Disease, University of Massachusetts, Worcester, MA, USA
- Pulmonary Center, Boston University School of Medicine, Boston, MA, USA
| | - Katrina E Traber
- Pulmonary Center, Boston University School of Medicine, Boston, MA, USA.
- Department of Medicine, Boston University School of Medicine, Boston, MA, USA.
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15
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Paidimuddala B, Cao J, Nash G, Xie Q, Wu H, Zhang L. Mechanism of NAIP-NLRC4 inflammasome activation revealed by cryo-EM structure of unliganded NAIP5. Nat Struct Mol Biol 2023; 30:159-166. [PMID: 36604500 PMCID: PMC10576962 DOI: 10.1038/s41594-022-00889-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 11/03/2022] [Indexed: 01/07/2023]
Abstract
The nucleotide-binding domain (NBD), leucine rich repeat (LRR) domain containing protein family (NLR family) apoptosis inhibitory proteins (NAIPs) are cytosolic receptors that play critical roles in the host defense against bacterial infection. NAIPs interact with conserved bacterial ligands and activate the NLR family caspase recruitment domain containing protein 4 (NLRC4) to initiate the NAIP-NLRC4 inflammasome pathway. Here we found the process of NAIP activation is completely different from NLRC4. Our cryo-EM structure of unliganded mouse NAIP5 adopts an unprecedented wide-open conformation, with the nucleating surface fully exposed and accessible to recruit inactive NLRC4. Upon ligand binding, the winged helix domain (WHD) of NAIP5 undergoes roughly 20° rotation to form a steric clash with the inactive NLRC4, which triggers the conformational change of NLRC4 from inactive to active state. We also show the rotation of WHD places the 17-18 loop at a position that directly bind the active NLRC4 and stabilize the NAIP5-NLRC4 complex. Overall, these data provide structural mechanisms of inactive NAIP5, the process of NAIP5 activation and NAIP-dependent NLRC4 activation.
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Affiliation(s)
- Bhaskar Paidimuddala
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University (OHSU), Portland, OR, USA
| | - Jianhao Cao
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University (OHSU), Portland, OR, USA
| | - Grady Nash
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University (OHSU), Portland, OR, USA
| | - Qing Xie
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University (OHSU), Portland, OR, USA
| | - Hao Wu
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA, USA
| | - Liman Zhang
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University (OHSU), Portland, OR, USA.
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16
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Chang MX. Emerging mechanisms and functions of inflammasome complexes in teleost fish. Front Immunol 2023; 14:1065181. [PMID: 36875130 PMCID: PMC9978379 DOI: 10.3389/fimmu.2023.1065181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Accepted: 02/06/2023] [Indexed: 02/18/2023] Open
Abstract
Inflammasomes are multiprotein complexes, which are assembled in response to a diverse range of exogenous pathogens and endogenous danger signals, leading to produce pro-inflammatory cytokines and induce pyroptotic cell death. Inflammasome components have been identified in teleost fish. Previous reviews have highlighted the conservation of inflammasome components in evolution, inflammasome function in zebrafish infectious and non-infectious models, and the mechanism that induce pyroptosis in fish. The activation of inflammasome involves the canonical and noncanonical pathways, which can play critical roles in the control of various inflammatory and metabolic diseases. The canonical inflammasomes activate caspase-1, and their signaling is initiated by cytosolic pattern recognition receptors. However the noncanonical inflammasomes activate inflammatory caspase upon sensing of cytosolic lipopolysaccharide from Gram-negative bacteria. In this review, we summarize the mechanisms of activation of canonical and noncanonical inflammasomes in teleost fish, with a particular focus on inflammasome complexes in response to bacterial infection. Furthermore, the functions of inflammasome-associated effectors, specific regulatory mechanisms of teleost inflammasomes and functional roles of inflammasomes in innate immune responses are also reviewed. The knowledge of inflammasome activation and pathogen clearance in teleost fish will shed new light on new molecular targets for treatment of inflammatory and infectious diseases.
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Affiliation(s)
- Ming Xian Chang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of InSciences, Wuhan, China.,College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China.,Innovation Academy for Seed Design, Chinese Academy of Sciences, Wuhan, China
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17
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Scott WP, Rauch I. Inducing Pyroptosis with FlaTox, RodTox, or NeedleTox. Methods Mol Biol 2023; 2641:27-36. [PMID: 37074639 DOI: 10.1007/978-1-0716-3040-2_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/20/2023]
Abstract
Targeted activation of the NAIP-NLRC4 inflammasome has proven very useful in the study of pyroptosis. FlaTox and derivative LFn-NAIP-ligand cytosolic delivery systems offer a unique opportunity to interrogate both ligand recognition and downstream effects of the NAIP-NLRC4 inflammasome pathway. Here we describe how to stimulate the NAIP-NLRC4 inflammasome in vitro and in vivo. We describe experimental setup and specific considerations for treatment of macrophages in vitro and in vivo injections using a murine model of systemic inflammasome activation. The in vitro readouts of inflammasome activation propidium iodide uptake and lactate dehydrogenase (LDH) release as well as the in vivo readouts of hematocrit and body temperature measurement are described.
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Affiliation(s)
- William P Scott
- Department of Molecular Microbiology and Immunology, Oregon Health & Science University, Portland, OR, USA
| | - Isabella Rauch
- Department of Molecular Microbiology and Immunology, Oregon Health & Science University, Portland, OR, USA.
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18
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Emming S, Monteleone MM, Kambara H, Starchenko A, Alley J, Nolan MA, Li W, Kilty I, Schroder K. Quantifying Cell Death Induced by the NLRC4 Inflammasome. Methods Mol Biol 2023; 2696:199-210. [PMID: 37578724 DOI: 10.1007/978-1-0716-3350-2_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
The Nod-like Receptor (NLR) apoptosis inhibitory proteins (NAIPs) are cytosolic receptors that sense cytosolic bacterial proteins. NAIP ligation induces its association with NLRC4, leading to the assembly of the NAIP/NLRC4 inflammasome, which induces the activation of the caspase-1 protease. Caspase-1 then cleaves pro-interleukin (IL)-1β, pro-IL-18, and gasdermin D and induces a form of pro-inflammatory cell death, pyroptosis. These processes culminate in host defense against bacterial infection. Here we describe methods for activating NAIP/NLRC4 inflammasome signalling in human and murine macrophages and quantifying inflammasome-induced cell death.
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Affiliation(s)
- Stefan Emming
- Institute for Molecular Bioscience, and Centre for Inflammation and Disease Research, The University of Queensland, St. Lucia, Australia
| | - Mercedes M Monteleone
- Institute for Molecular Bioscience, and Centre for Inflammation and Disease Research, The University of Queensland, St. Lucia, Australia
| | | | | | | | | | - Wei Li
- Quench Bio, Inc., Cambridge, MA, USA
| | | | - Kate Schroder
- Institute for Molecular Bioscience, and Centre for Inflammation and Disease Research, The University of Queensland, St. Lucia, Australia.
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19
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Schmacke NA, O'Duill F, Gaidt MM, Szymanska I, Kamper JM, Schmid-Burgk JL, Mädler SC, Mackens-Kiani T, Kozaki T, Chauhan D, Nagl D, Stafford CA, Harz H, Fröhlich AL, Pinci F, Ginhoux F, Beckmann R, Mann M, Leonhardt H, Hornung V. IKKβ primes inflammasome formation by recruiting NLRP3 to the trans-Golgi network. Immunity 2022; 55:2271-2284.e7. [PMID: 36384135 PMCID: PMC7614333 DOI: 10.1016/j.immuni.2022.10.021] [Citation(s) in RCA: 39] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 07/17/2022] [Accepted: 10/26/2022] [Indexed: 11/17/2022]
Abstract
The NLRP3 inflammasome plays a central role in antimicrobial defense as well as in the context of sterile inflammatory conditions. NLRP3 activity is governed by two independent signals: the first signal primes NLRP3, rendering it responsive to the second signal, which then triggers inflammasome formation. Our understanding of how NLRP3 priming contributes to inflammasome activation remains limited. Here, we show that IKKβ, a kinase activated during priming, induces recruitment of NLRP3 to phosphatidylinositol-4-phosphate (PI4P), a phospholipid enriched on the trans-Golgi network. NEK7, a mitotic spindle kinase that had previously been thought to be indispensable for NLRP3 activation, was redundant for inflammasome formation when IKKβ recruited NLRP3 to PI4P. Studying iPSC-derived human macrophages revealed that the IKKβ-mediated NEK7-independent pathway constitutes the predominant NLRP3 priming mechanism in human myeloid cells. Our results suggest that PI4P binding represents a primed state into which NLRP3 is brought by IKKβ activity.
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Affiliation(s)
- Niklas A Schmacke
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Fionan O'Duill
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Moritz M Gaidt
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Inga Szymanska
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Julia M Kamper
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Jonathan L Schmid-Burgk
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Sophia C Mädler
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Timur Mackens-Kiani
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Tatsuya Kozaki
- Singapore Immunology Network (SIgN), Agency for Science, Technology & Research (A∗STAR), 8A Biomedical Grove, Immunos Building #3-4, Biopolis, Singapore 138648, Singapore
| | - Dhruv Chauhan
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Dennis Nagl
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Che A Stafford
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Hartmann Harz
- Faculty of Biology, Human Biology and BioImaging, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
| | - Adrian L Fröhlich
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Francesca Pinci
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Florent Ginhoux
- Singapore Immunology Network (SIgN), Agency for Science, Technology & Research (A∗STAR), 8A Biomedical Grove, Immunos Building #3-4, Biopolis, Singapore 138648, Singapore; Shanghai Institute of Immunology, Shanghai JiaoTong University School of Medicine, 280 South Chongqing Road, Shanghai 200025, China; Translational Immunology Institute, SingHealth Duke-NUS Academic Medical Centre, Singapore 169856, Singapore
| | - Roland Beckmann
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Matthias Mann
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Heinrich Leonhardt
- Faculty of Biology, Human Biology and BioImaging, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
| | - Veit Hornung
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, 81377 Munich, Germany.
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20
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López‐Haber C, Netting DJ, Hutchins Z, Ma X, Hamilton KE, Mantegazza AR. The phagosomal solute transporter SLC15A4 promotes inflammasome activity via mTORC1 signaling and autophagy restraint in dendritic cells. EMBO J 2022; 41:e111161. [PMID: 36031853 PMCID: PMC9574736 DOI: 10.15252/embj.2022111161] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 07/22/2022] [Accepted: 08/01/2022] [Indexed: 01/18/2023] Open
Abstract
Phagocytosis is the necessary first step to sense foreign microbes or particles and enables activation of innate immune pathways such as inflammasomes. However, the molecular mechanisms underlying how phagosomes modulate inflammasome activity are not fully understood. We show that in murine dendritic cells (DCs), the lysosomal histidine/peptide solute carrier transporter SLC15A4, associated with human inflammatory disorders, is recruited to phagosomes and is required for optimal inflammasome activity after infectious or sterile stimuli. Dextran sodium sulfate-treated SLC15A4-deficient mice exhibit decreased colon inflammation, reduced IL-1β production by intestinal DCs, and increased autophagy. Similarly, SLC15A4-deficient DCs infected with Salmonella typhimurium show reduced caspase-1 cleavage and IL-1β production. This correlates with peripheral NLRC4 inflammasome assembly and increased autophagy. Overexpression of constitutively active mTORC1 rescues decreased IL-1β levels and caspase1 cleavage, and restores perinuclear inflammasome positioning. Our findings support that SLC15A4 couples phagocytosis with inflammasome perinuclear assembly and inhibition of autophagy through phagosomal content sensing. Our data also reveal the previously unappreciated importance of mTORC1 signaling pathways to promote and sustain inflammasome activity.
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Affiliation(s)
- Cynthia López‐Haber
- Department of Pathology and Laboratory MedicineChildren's Hospital of PhiladelphiaPhiladelphiaPAUSA
- Department of Pathology and Laboratory Medicine, Perelman School of MedicineUniversity of PennsylvaniaPhiladelphiaPAUSA
- Present address:
Department of Microbiology and Immunology, Sidney Kimmel Medical CollegeThomas Jefferson UniversityPhiladelphiaPAUSA
| | - Daniel J Netting
- Department of Microbiology and Immunology, Sidney Kimmel Medical CollegeThomas Jefferson UniversityPhiladelphiaPAUSA
| | - Zachary Hutchins
- Department of Microbiology and Immunology, Sidney Kimmel Medical CollegeThomas Jefferson UniversityPhiladelphiaPAUSA
| | - Xianghui Ma
- Division of Gastroenterology, Hepatology, and Nutrition, Department of PediatricsChildren's Hospital of PhiladelphiaPhiladelphiaPAUSA
| | - Kathryn E Hamilton
- Division of Gastroenterology, Hepatology, and Nutrition, Department of PediatricsChildren's Hospital of PhiladelphiaPhiladelphiaPAUSA
| | - Adriana R Mantegazza
- Department of Pathology and Laboratory MedicineChildren's Hospital of PhiladelphiaPhiladelphiaPAUSA
- Department of Pathology and Laboratory Medicine, Perelman School of MedicineUniversity of PennsylvaniaPhiladelphiaPAUSA
- Present address:
Department of Microbiology and Immunology, Sidney Kimmel Medical CollegeThomas Jefferson UniversityPhiladelphiaPAUSA
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21
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Naseer N, Zhang J, Bauer R, Constant DA, Nice TJ, Brodsky IE, Rauch I, Shin S. Salmonella enterica Serovar Typhimurium Induces NAIP/NLRC4- and NLRP3/ASC-Independent, Caspase-4-Dependent Inflammasome Activation in Human Intestinal Epithelial Cells. Infect Immun 2022; 90:e0066321. [PMID: 35678562 PMCID: PMC9302179 DOI: 10.1128/iai.00663-21] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 05/23/2022] [Indexed: 01/09/2023] Open
Abstract
Salmonella enterica serovar Typhimurium is a Gram-negative pathogen that causes diseases ranging from gastroenteritis to systemic infection and sepsis. Salmonella uses type III secretion systems (T3SS) to inject effectors into host cells. While these effectors are necessary for bacterial invasion and intracellular survival, intracellular delivery of T3SS products also enables detection of translocated Salmonella ligands by cytosolic immune sensors. Some of these sensors form multimeric complexes called inflammasomes, which activate caspases that lead to interleukin-1 (IL-1) family cytokine release and pyroptosis. In particular, the Salmonella T3SS needle, inner rod, and flagellin proteins activate the NAIP/NLRC4 inflammasome in murine intestinal epithelial cells (IECs), which leads to restriction of bacterial replication and extrusion of infected IECs into the intestinal lumen, thereby preventing systemic dissemination of Salmonella. While these processes are quite well studied in mice, the role of the NAIP/NLRC4 inflammasome in human IECs remains unknown. Unexpectedly, we found the NAIP/NLRC4 inflammasome is dispensable for early inflammasome responses to Salmonella in both human IEC lines and enteroids. Additionally, NLRP3 and the adaptor protein ASC are not required for inflammasome activation in Caco-2 cells. Instead, we observed a necessity for caspase-4 and gasdermin D pore-forming activity in mediating inflammasome responses to Salmonella in Caco-2 cells. These findings suggest that unlike murine IECs, human IECs do not rely on NAIP/NLRC4 or NLRP3/ASC inflammasomes and instead primarily use caspase-4 to mediate inflammasome responses to Salmonella pathogenicity island 1 (SPI-1)-expressing Salmonella.
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Affiliation(s)
- Nawar Naseer
- Department of Microbiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Jenna Zhang
- Department of Microbiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Renate Bauer
- Department of Molecular Microbiology and Immunology, Oregon Health & Science University, Portland, Oregon, USA
- Department of Biosciences, Paris Lodron University of Salzburg, Salzburg, Austria
| | - David A. Constant
- Department of Molecular Microbiology and Immunology, Oregon Health & Science University, Portland, Oregon, USA
| | - Timothy J. Nice
- Department of Molecular Microbiology and Immunology, Oregon Health & Science University, Portland, Oregon, USA
| | - Igor E. Brodsky
- Department of Pathobiology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, Pennsylvania, USA
| | - Isabella Rauch
- Department of Molecular Microbiology and Immunology, Oregon Health & Science University, Portland, Oregon, USA
| | - Sunny Shin
- Department of Microbiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
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22
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Caspase-1-driven neutrophil pyroptosis and its role in host susceptibility to Pseudomonas aeruginosa. PLoS Pathog 2022; 18:e1010305. [PMID: 35849616 PMCID: PMC9345480 DOI: 10.1371/journal.ppat.1010305] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 08/02/2022] [Accepted: 06/01/2022] [Indexed: 11/22/2022] Open
Abstract
Multiple regulated neutrophil cell death programs contribute to host defense against infections. However, despite expressing all necessary inflammasome components, neutrophils are thought to be generally defective in Caspase-1-dependent pyroptosis. By screening different bacterial species, we found that several Pseudomonas aeruginosa (P. aeruginosa) strains trigger Caspase-1-dependent pyroptosis in human and murine neutrophils. Notably, deletion of Exotoxins U or S in P. aeruginosa enhanced neutrophil death to Caspase-1-dependent pyroptosis, suggesting that these exotoxins interfere with this pathway. Mechanistically, P. aeruginosa Flagellin activates the NLRC4 inflammasome, which supports Caspase-1-driven interleukin (IL)-1β secretion and Gasdermin D (GSDMD)-dependent neutrophil pyroptosis. Furthermore, P. aeruginosa-induced GSDMD activation triggers Calcium-dependent and Peptidyl Arginine Deaminase-4-driven histone citrullination and translocation of neutrophil DNA into the cell cytosol without inducing extracellular Neutrophil Extracellular Traps. Finally, we show that neutrophil Caspase-1 contributes to IL-1β production and susceptibility to pyroptosis-inducing P. aeruginosa strains in vivo. Overall, we demonstrate that neutrophils are not universally resistant for Caspase-1-dependent pyroptosis. Neutrophils play an essential role against infections. Although multiple neutrophil death programs contribute to host defense against infections, neutrophils are thought to be defective in Caspase-1-dependent pyroptosis. We screened several microbial species for the capacity to overcome neutrophil resistance to Caspase-1-driven pyroptosis, and show that the bacterium Pseudomonas aeruginosa specifically engages the NLRC4 inflammasome to promote Caspase-1-dependent Gasdermin D activation and subsequent neutrophil pyroptosis. Furthermore, NLRC4 inflammasome-driven pyroptosis leads to histone citrullination, nuclear DNA decondensation and expansion into the host cell cytosol. However, Neutrophil Extracellular Trap (NET) are not formed because DNA is kept in the intracellular space despite plasma membrane permeabilization and extracellular release of soluble and insoluble alarmins. Finally, in vivo P. aeruginosa infections highlight that Caspase-1-driven neutrophil pyroptosis is detrimental to the host upon P. aeruginosa infection. Altogether, our results demonstrate Caspase-1-dependent pyroptosis in neutrophils as a process that contributes to host susceptibility to P. aeruginosa infection.
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23
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Martynova E, Rizvanov A, Urbanowicz RA, Khaiboullina S. Inflammasome Contribution to the Activation of Th1, Th2, and Th17 Immune Responses. Front Microbiol 2022; 13:851835. [PMID: 35369454 PMCID: PMC8969514 DOI: 10.3389/fmicb.2022.851835] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 02/22/2022] [Indexed: 12/24/2022] Open
Abstract
Inflammasomes are cytosolic polyprotein complexes formed in response to various external and internal stimuli, including viral and bacterial antigens. The main product of the inflammasome is active caspase 1 which proteolytically cleaves, releasing functional interleukin-1 beta (IL-1β) and interleukin-18 (IL-18). These cytokines play a central role in shaping immune response to pathogens. In this review, we will focus on the mechanisms of inflammasome activation, as well as their role in development of Th1, Th2, and Th17 lymphocytes. The contribution of cytokines IL-1β, IL-18, and IL-33, products of activated inflammasomes, are summarized. Additionally, the role of cytokines released from tissue cells in promoting differentiation of lymphocyte populations is discussed.
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Affiliation(s)
| | | | - Richard A. Urbanowicz
- Department of Infection Biology and Microbiomes, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
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24
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Saldana-Morales FB, Kim DV, Tsai MT, Diehl GE. Healthy Intestinal Function Relies on Coordinated Enteric Nervous System, Immune System, and Epithelium Responses. Gut Microbes 2022; 13:1-14. [PMID: 33929291 PMCID: PMC8096330 DOI: 10.1080/19490976.2021.1916376] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
During both health and disease, a coordinated response between the epithelium, immune system, and enteric nervous system is required for proper intestinal function. While each system responds to a number of common stimuli, their coordinated responses support digestion as well as responses and recovery following injury or pathogenic infections. In this review, we discuss how individual responses to common signals work together to support these critical functions.
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Affiliation(s)
- Fatima B. Saldana-Morales
- Graduate School of Biomedical Sciences, Baylor College of Medicine, HoustonTXUSA,Immunology Program of the Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NYUSA
| | - Dasom V. Kim
- Immunology Program of the Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NYUSA,Immunology and Microbial Pathogenesis Program, Weill Cornell Medical College, Cornell University, New York, NY, USA
| | - Ming-Ting Tsai
- Graduate School of Biomedical Sciences, Baylor College of Medicine, HoustonTXUSA,Immunology Program of the Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NYUSA
| | - Gretchen E. Diehl
- Immunology Program of the Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NYUSA,Immunology and Microbial Pathogenesis Program, Weill Cornell Medical College, Cornell University, New York, NY, USA,CONTACT Gretchen E. Diehl Immunology Program of the Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY10021, USA. Immunology and Microbial Pathogenesis Program, Weill Cornell Medical College, Cornell University, New York, NY, USA
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25
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Demarco B, Ramos S, Broz P. Detection of Gasdermin Activation and Lytic Cell Death During Pyroptosis and Apoptosis. Methods Mol Biol 2022; 2523:209-237. [PMID: 35759200 DOI: 10.1007/978-1-0716-2449-4_14] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Cytosolic pattern recognition receptors trigger pyroptosis by detection of danger- or pathogen-associated molecular patterns. These receptors initiate the assembly of inflammasomes, multimeric protein complexes that drive caspase-1 activation. Active caspase-1 cleaves the proinflammatory cytokines IL-1β and IL-18 and the pore-forming protein gasdermin-D (GSDMD) thereby liberating its N-terminal domain. The GSDMD N-termini form multimeric pores at the plasma membrane that allow leakage of intracellular content and ultimately trigger a type of cell death called "pyroptosis." Emerging studies have revealed that GSDMD is also processed by apoptotic caspases-8/-3/-7. In this chapter, we aim to describe methods to monitor lytic cell death and to distinguish between GSDMD processing events and the GSDMD fragments that are generated after pyroptosis or apoptosis induction. We also illustrate the difference between GSDMD pore formation, and final cell lysis, and how this affects to the release of intracellular content. Finally, we show that the activation of another pore-forming protein, gasdermin-E, does not exclusively translate into lytic cell death in bone marrow-derived macrophages.
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Affiliation(s)
- Benjamin Demarco
- Department of Biochemistry, University of Lausanne, Epalinges, Switzerland
- Kennedy Institute of Rheumatology, NDORMS, University of Oxford, Oxford, UK
| | - Saray Ramos
- Department of Biochemistry, University of Lausanne, Epalinges, Switzerland
| | - Petr Broz
- Department of Biochemistry, University of Lausanne, Epalinges, Switzerland.
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26
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Naseer N, Egan MS, Reyes Ruiz VM, Scott WP, Hunter EN, Demissie T, Rauch I, Brodsky IE, Shin S. Human NAIP/NLRC4 and NLRP3 inflammasomes detect Salmonella type III secretion system activities to restrict intracellular bacterial replication. PLoS Pathog 2022; 18:e1009718. [PMID: 35073381 PMCID: PMC8812861 DOI: 10.1371/journal.ppat.1009718] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 02/03/2022] [Accepted: 12/27/2021] [Indexed: 01/16/2023] Open
Abstract
Salmonella enterica serovar Typhimurium is a Gram-negative pathogen that uses two distinct type III secretion systems (T3SSs), termed Salmonella pathogenicity island (SPI)-1 and SPI-2, to deliver virulence factors into the host cell. The SPI-1 T3SS enables Salmonella to invade host cells, while the SPI-2 T3SS facilitates Salmonella's intracellular survival. In mice, a family of cytosolic immune sensors, including NAIP1, NAIP2, and NAIP5/6, recognizes the SPI-1 T3SS needle, inner rod, and flagellin proteins, respectively. Ligand recognition triggers assembly of the NAIP/NLRC4 inflammasome, which mediates caspase-1 activation, IL-1 family cytokine secretion, and pyroptosis of infected cells. In contrast to mice, humans encode a single NAIP that broadly recognizes all three ligands. The role of NAIP/NLRC4 or other inflammasomes during Salmonella infection of human macrophages is unclear. We find that although the NAIP/NLRC4 inflammasome is essential for detecting T3SS ligands in human macrophages, it is partially required for responses to infection, as Salmonella also activated the NLRP3 and CASP4/5 inflammasomes. Importantly, we demonstrate that combinatorial NAIP/NLRC4 and NLRP3 inflammasome activation restricts Salmonella replication in human macrophages. In contrast to SPI-1, the SPI-2 T3SS inner rod is not sensed by human or murine NAIPs, which is thought to allow Salmonella to evade host recognition and replicate intracellularly. Intriguingly, we find that human NAIP detects the SPI-2 T3SS needle protein. Critically, in the absence of both flagellin and the SPI-1 T3SS, the NAIP/NLRC4 inflammasome still controlled intracellular Salmonella burden. These findings reveal that recognition of Salmonella SPI-1 and SPI-2 T3SSs and engagement of both the NAIP/NLRC4 and NLRP3 inflammasomes control Salmonella infection in human macrophages.
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Affiliation(s)
- Nawar Naseer
- Department of Microbiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| | - Marisa S. Egan
- Department of Microbiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| | - Valeria M. Reyes Ruiz
- Department of Microbiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| | - William P. Scott
- Department of Molecular Microbiology and Immunology, Oregon Health & Science University, Portland, Oregon
| | - Emma N. Hunter
- Department of Microbiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| | - Tabitha Demissie
- Department of Microbiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| | - Isabella Rauch
- Department of Molecular Microbiology and Immunology, Oregon Health & Science University, Portland, Oregon
| | - Igor E. Brodsky
- Department of Pathobiology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, Pennsylvania
| | - Sunny Shin
- Department of Microbiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
- * E-mail:
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27
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Deets KA, Nichols Doyle R, Rauch I, Vance RE. Inflammasome activation leads to cDC1-independent cross-priming of CD8 T cells by epithelial cell-derived antigen. eLife 2021; 10:e72082. [PMID: 34939932 PMCID: PMC8719880 DOI: 10.7554/elife.72082] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 12/21/2021] [Indexed: 12/17/2022] Open
Abstract
The innate immune system detects pathogens and initiates adaptive immune responses. Inflammasomes are central components of the innate immune system, but whether inflammasomes provide sufficient signals to activate adaptive immunity is unclear. In intestinal epithelial cells (IECs), inflammasomes activate a lytic form of cell death called pyroptosis, leading to epithelial cell expulsion and the release of cytokines. Here, we employed a genetic system to show that simultaneous antigen expression and inflammasome activation specifically in IECs is sufficient to activate CD8+ T cells. By genetic elimination of direct T cell priming by IECs, we found that IEC-derived antigens were cross-presented to CD8+ T cells. However, cross-presentation of IEC-derived antigen to CD8+ T cells only partially depended on IEC pyroptosis. In the absence of inflammasome activation, cross-priming of CD8+ T cells required Batf3+ dendritic cells (conventional type one dendritic cells [cDC1]), whereas cross-priming in the presence of inflammasome activation required a Zbtb46+ but Batf3-independent cDC population. These data suggest the existence of parallel inflammasome-dependent and inflammasome-independent pathways for cross-presentation of IEC-derived antigens.
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Affiliation(s)
- Katherine A Deets
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Randilea Nichols Doyle
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Isabella Rauch
- Department of Molecular Microbiology and Immunology, Oregon Health and Science UniversityPortlandUnited States
| | - Russell E Vance
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
- Cancer Research Laboratory, University of California, BerkeleyBerkeleyUnited States
- Howard Hughes Medical Institute, University of California, BerkeleyBerkeleyUnited States
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28
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Wang SB, Narendran S, Hirahara S, Varshney A, Pereira F, Apicella I, Ambati M, Ambati VL, Yerramothu P, Ambati K, Nagasaka Y, Argyle D, Huang P, Baker KL, Marion KM, Gupta K, Liu B, Hinton DR, Canna SW, Sallam T, Sadda SR, Kerur N, Gelfand BD, Ambati J. DDX17 is an essential mediator of sterile NLRC4 inflammasome activation by retrotransposon RNAs. Sci Immunol 2021; 6:eabi4493. [PMID: 34860583 PMCID: PMC8767314 DOI: 10.1126/sciimmunol.abi4493] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Detection of microbial products by multiprotein complexes known as inflammasomes is pivotal to host defense against pathogens. Nucleotide-binding domain leucine-rich repeat (NLR) CARD domain containing 4 (NLRC4) forms an inflammasome in response to bacterial products; this requires their detection by NLR family apoptosis inhibitory proteins (NAIPs), with which NLRC4 physically associates. However, the mechanisms underlying sterile NLRC4 inflammasome activation, which is implicated in chronic noninfectious diseases, remain unknown. Here, we report that endogenous short interspersed nuclear element (SINE) RNAs, which promote atrophic macular degeneration (AMD) and systemic lupus erythematosus (SLE), induce NLRC4 inflammasome activation independent of NAIPs. We identify DDX17, a DExD/H box RNA helicase, as the sensor of SINE RNAs that licenses assembly of an inflammasome comprising NLRC4, NLR pyrin domain–containing protein 3, and apoptosis-associated speck-like protein–containing CARD and induces caspase-1 activation and cytokine release. Inhibiting DDX17-mediated NLRC4 inflammasome activation decreased interleukin-18 release in peripheral blood mononuclear cells of patients with SLE and prevented retinal degeneration in an animal model of AMD. Our findings uncover a previously unrecognized noncanonical NLRC4 inflammasome activated by endogenous retrotransposons and provide potential therapeutic targets for SINE RNA–driven diseases.
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Affiliation(s)
- Shao-bin Wang
- Center for Advanced Vision Science, University of Virginia School of Medicine, Charlottesville, VA, USA
- Department of Ophthalmology, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Siddharth Narendran
- Center for Advanced Vision Science, University of Virginia School of Medicine, Charlottesville, VA, USA
- Department of Ophthalmology, University of Virginia School of Medicine, Charlottesville, VA, USA
- Aravind Eye Care System, Madurai, India
| | - Shuichiro Hirahara
- Center for Advanced Vision Science, University of Virginia School of Medicine, Charlottesville, VA, USA
- Department of Ophthalmology, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Akhil Varshney
- Center for Advanced Vision Science, University of Virginia School of Medicine, Charlottesville, VA, USA
- Department of Ophthalmology, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Felipe Pereira
- Center for Advanced Vision Science, University of Virginia School of Medicine, Charlottesville, VA, USA
- Department of Ophthalmology, University of Virginia School of Medicine, Charlottesville, VA, USA
- Departamento de Oftalmologia e Ciências Visuais, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo 04023-062, Brazil
| | - Ivana Apicella
- Center for Advanced Vision Science, University of Virginia School of Medicine, Charlottesville, VA, USA
- Department of Ophthalmology, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Meenakshi Ambati
- Center for Advanced Vision Science, University of Virginia School of Medicine, Charlottesville, VA, USA
- Department of Ophthalmology, University of Virginia School of Medicine, Charlottesville, VA, USA
- Center for Digital Image Evaluation, Charlottesville, VA, USA
| | - Vidya L. Ambati
- Center for Digital Image Evaluation, Charlottesville, VA, USA
| | - Praveen Yerramothu
- Center for Advanced Vision Science, University of Virginia School of Medicine, Charlottesville, VA, USA
- Department of Ophthalmology, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Kameshwari Ambati
- Center for Advanced Vision Science, University of Virginia School of Medicine, Charlottesville, VA, USA
- Department of Ophthalmology, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Yosuke Nagasaka
- Center for Advanced Vision Science, University of Virginia School of Medicine, Charlottesville, VA, USA
- Department of Ophthalmology, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Dionne Argyle
- Center for Advanced Vision Science, University of Virginia School of Medicine, Charlottesville, VA, USA
- Department of Ophthalmology, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Peirong Huang
- Center for Advanced Vision Science, University of Virginia School of Medicine, Charlottesville, VA, USA
- Department of Ophthalmology, University of Virginia School of Medicine, Charlottesville, VA, USA
| | | | | | - Kartik Gupta
- Department of Surgery, University of Wisconsin-Madison, Madison, WI, USA
| | - Bo Liu
- Department of Surgery, University of Wisconsin-Madison, Madison, WI, USA
| | - David R. Hinton
- Departments of Pathology and Ophthalmology, USC Roski Eye Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA, USA
| | - Scott W. Canna
- Pediatric Rheumatology & RK Mellon Institute for Pediatric Research, Children’s Hospital of Pittsburgh of UPMC, Pittsburgh, PA, USA
| | - Tamer Sallam
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
- Molecular Biology Institute, Center for Health Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Srinivas R. Sadda
- Doheny Eye Institute, Los Angeles, Los Angeles, CA, USA
- Department of Ophthalmology, David Geffen School of Medicine, University of California–Los Angeles, Los Angeles, CA, USA
| | - Nagaraj Kerur
- Center for Advanced Vision Science, University of Virginia School of Medicine, Charlottesville, VA, USA
- Department of Ophthalmology, University of Virginia School of Medicine, Charlottesville, VA, USA
- Department of Pathology, University of Virginia School of Medicine, Charlottesville, VA, USA
- Department of Neuroscience, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Bradley D. Gelfand
- Center for Advanced Vision Science, University of Virginia School of Medicine, Charlottesville, VA, USA
- Department of Ophthalmology, University of Virginia School of Medicine, Charlottesville, VA, USA
- Department of Biomedical Engineering, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Jayakrishna Ambati
- Center for Advanced Vision Science, University of Virginia School of Medicine, Charlottesville, VA, USA
- Department of Ophthalmology, University of Virginia School of Medicine, Charlottesville, VA, USA
- Department of Pathology, University of Virginia School of Medicine, Charlottesville, VA, USA
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, VA, USA
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29
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Evavold CL, Hafner-Bratkovič I, Devant P, D'Andrea JM, Ngwa EM, Boršić E, Doench JG, LaFleur MW, Sharpe AH, Thiagarajah JR, Kagan JC. Control of gasdermin D oligomerization and pyroptosis by the Ragulator-Rag-mTORC1 pathway. Cell 2021; 184:4495-4511.e19. [PMID: 34289345 PMCID: PMC8380731 DOI: 10.1016/j.cell.2021.06.028] [Citation(s) in RCA: 216] [Impact Index Per Article: 72.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 06/04/2021] [Accepted: 06/23/2021] [Indexed: 12/26/2022]
Abstract
The process of pyroptosis is mediated by inflammasomes and a downstream effector known as gasdermin D (GSDMD). Upon cleavage by inflammasome-associated caspases, the N-terminal domain of GSDMD forms membrane pores that promote cytolysis. Numerous proteins promote GSDMD cleavage, but none are known to be required for pore formation after GSDMD cleavage. Herein, we report a forward genetic screen that identified the Ragulator-Rag complex as being necessary for GSDMD pore formation and pyroptosis in macrophages. Mechanistic analysis revealed that Ragulator-Rag is not required for GSDMD cleavage upon inflammasome activation but rather promotes GSDMD oligomerization in the plasma membrane. Defects in GSDMD oligomerization and pore formation can be rescued by mitochondrial poisons that stimulate reactive oxygen species (ROS) production, and ROS modulation impacts the ability of inflammasome pathways to promote pore formation downstream of GSDMD cleavage. These findings reveal an unexpected link between key regulators of immunity (inflammasome-GSDMD) and metabolism (Ragulator-Rag).
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Affiliation(s)
- Charles L Evavold
- Division of Gastroenterology, Boston Children's Hospital and Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA.
| | - Iva Hafner-Bratkovič
- Division of Gastroenterology, Boston Children's Hospital and Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA; Department of Synthetic Biology and Immunology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia; EN-FIST Centre of Excellence, Trg Osvobodilne fronte 13, 1000 Ljubljana, Slovenia
| | - Pascal Devant
- Division of Gastroenterology, Boston Children's Hospital and Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Jasmin M D'Andrea
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA; Evergrande Center for Immunological Diseases, Harvard Medical School and Brigham and Women's Hospital, Boston, MA 02115, USA
| | - Elsy M Ngwa
- Division of Gastroenterology, Boston Children's Hospital and Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Elvira Boršić
- Department of Synthetic Biology and Immunology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia
| | - John G Doench
- Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA 02142, USA
| | - Martin W LaFleur
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA; Evergrande Center for Immunological Diseases, Harvard Medical School and Brigham and Women's Hospital, Boston, MA 02115, USA
| | - Arlene H Sharpe
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA; Evergrande Center for Immunological Diseases, Harvard Medical School and Brigham and Women's Hospital, Boston, MA 02115, USA; Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA 02142, USA
| | - Jay R Thiagarajah
- Division of Gastroenterology, Boston Children's Hospital and Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Jonathan C Kagan
- Division of Gastroenterology, Boston Children's Hospital and Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA.
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30
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Wen J, Xuan B, Liu Y, Wang L, He L, Meng X, Zhou T, Wang Y. Updating the NLRC4 Inflammasome: from Bacterial Infections to Autoimmunity and Cancer. Front Immunol 2021; 12:702527. [PMID: 34276697 PMCID: PMC8283967 DOI: 10.3389/fimmu.2021.702527] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 06/17/2021] [Indexed: 01/07/2023] Open
Abstract
Inflammasomes comprise a family of cytosolic multi-protein complexes that modulate the activation of cysteine-aspartate-specific protease 1 (caspase-1) and promote the maturation and secretion of interleukin (IL)-1β and IL-18, leading to an inflammatory response. Different types of inflammasomes are defined by their sensor protein which recognizes pathogenic ligands and then directs inflammasome assembly. Although the specific molecular mechanisms underlying the activation of most inflammasomes are still unclear, NLRC4 inflammasomes have emerged as multifaceted agents of the innate immune response, playing important roles in immune defense against a variety of pathogens. Other studies have also expanded the scope of NLRC4 inflammasomes to include a range of inherited human autoimmune diseases as well as proposed roles in cancer. In this review article, we provide an updated overview of NLRC4 inflammasomes, describing their composition, activation mechanisms and roles in both microbial infections and other disease conditions.
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Affiliation(s)
- Jiexia Wen
- Department of Central Laboratory, First Hospital of Qinhuangdao, Hebei Medical University, Qinhuangdao, China
| | - Bin Xuan
- Department of General Surgery, First Hospital of Qinhuangdao, Hebei Medical University, Qinhuangdao, China
| | - Yang Liu
- Department of General Surgery, First Hospital of Qinhuangdao, Hebei Medical University, Qinhuangdao, China
| | - Liwei Wang
- Department of General Surgery, First Hospital of Qinhuangdao, Hebei Medical University, Qinhuangdao, China
| | - Li He
- Department of General Surgery, First Hospital of Qinhuangdao, Hebei Medical University, Qinhuangdao, China
| | - Xiangcai Meng
- Department of General Surgery, First Hospital of Qinhuangdao, Hebei Medical University, Qinhuangdao, China
| | - Tao Zhou
- Department of General Surgery, First Hospital of Qinhuangdao, Hebei Medical University, Qinhuangdao, China
| | - Yimin Wang
- Department of Central Laboratory, First Hospital of Qinhuangdao, Hebei Medical University, Qinhuangdao, China.,Department of General Surgery, First Hospital of Qinhuangdao, Hebei Medical University, Qinhuangdao, China
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31
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Pei G, Dorhoi A. NOD-Like Receptors: Guards of Cellular Homeostasis Perturbation during Infection. Int J Mol Sci 2021; 22:ijms22136714. [PMID: 34201509 PMCID: PMC8268748 DOI: 10.3390/ijms22136714] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 06/14/2021] [Accepted: 06/18/2021] [Indexed: 12/30/2022] Open
Abstract
The innate immune system relies on families of pattern recognition receptors (PRRs) that detect distinct conserved molecular motifs from microbes to initiate antimicrobial responses. Activation of PRRs triggers a series of signaling cascades, leading to the release of pro-inflammatory cytokines, chemokines and antimicrobials, thereby contributing to the early host defense against microbes and regulating adaptive immunity. Additionally, PRRs can detect perturbation of cellular homeostasis caused by pathogens and fine-tune the immune responses. Among PRRs, nucleotide binding oligomerization domain (NOD)-like receptors (NLRs) have attracted particular interest in the context of cellular stress-induced inflammation during infection. Recently, mechanistic insights into the monitoring of cellular homeostasis perturbation by NLRs have been provided. We summarize the current knowledge about the disruption of cellular homeostasis by pathogens and focus on NLRs as innate immune sensors for its detection. We highlight the mechanisms employed by various pathogens to elicit cytoskeleton disruption, organelle stress as well as protein translation block, point out exemplary NLRs that guard cellular homeostasis during infection and introduce the concept of stress-associated molecular patterns (SAMPs). We postulate that integration of information about microbial patterns, danger signals, and SAMPs enables the innate immune system with adequate plasticity and precision in elaborating responses to microbes of variable virulence.
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Affiliation(s)
- Gang Pei
- Institute of Immunology, Friedrich-Loeffler-Institut, 17493 Greifswald, Germany
- Correspondence: (G.P.); (A.D.)
| | - Anca Dorhoi
- Institute of Immunology, Friedrich-Loeffler-Institut, 17493 Greifswald, Germany
- Faculty of Mathematics and Natural Sciences, University of Greifswald, 17489 Greifswald, Germany
- Correspondence: (G.P.); (A.D.)
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32
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Liu T, Liu S, Zhou X. Innate Immune Responses and Pulmonary Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1304:53-71. [PMID: 34019263 DOI: 10.1007/978-3-030-68748-9_4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Innate immunity is the first defense line of the host against various infectious pathogens, environmental insults, and other stimuli causing cell damages. Upon stimulation, pattern recognition receptors (PRRs) act as sensors to activate innate immune responses, containing NF-κB signaling, IFN response, and inflammasome activation. Toll-like receptors (TLRs), retinoic acid-inducible gene I-like receptors (RLRs), NOD-like receptors (NLRs), and other nucleic acid sensors are involved in innate immune responses. The activation of innate immune responses can facilitate the host to eliminate pathogens and maintain tissue homeostasis. However, the activity of innate immune responses needs to be tightly controlled to ensure the optimal intensity and duration of activation under various contexts. Uncontrolled innate immune responses can lead to various disorders associated with aberrant inflammatory response, including pulmonary diseases such as COPD, asthma, and COVID-19. In this chapter, we will have a broad overview of how innate immune responses function and the regulation and activation of innate immune response at molecular levels as well as their contribution to various pulmonary diseases. A better understanding of such association between innate immune responses and pulmonary diseases may provide potential therapeutic strategies.
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Affiliation(s)
- Tao Liu
- Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Siqi Liu
- Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Xiaobo Zhou
- Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA.
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33
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Bacterial detection by NAIP/NLRC4 elicits prompt contractions of intestinal epithelial cell layers. Proc Natl Acad Sci U S A 2021; 118:2013963118. [PMID: 33846244 PMCID: PMC8072224 DOI: 10.1073/pnas.2013963118] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The gut epithelium serves to maximize the surface for nutrient and fluid uptake, but at the same time must provide a tight barrier to pathogens and remove damaged intestinal epithelial cells (IECs) without jeopardizing barrier integrity. How the epithelium coordinates these tasks remains a question of significant interest. We used imaging and an optical flow analysis pipeline to study the dynamicity of untransformed murine and human intestinal epithelia, cultured atop flexible hydrogel supports. Infection with the pathogen Salmonella Typhimurium (STm) within minutes elicited focal contractions with inward movements of up to ∼1,000 IECs. Genetics approaches and chimeric epithelial monolayers revealed contractions to be triggered by the NAIP/NLRC4 inflammasome, which sensed type-III secretion system and flagellar ligands upon bacterial invasion, converting the local tissue into a contraction epicenter. Execution of the response required swift sublytic Gasdermin D pore formation, ion fluxes, and the propagation of a myosin contraction pulse across the tissue. Importantly, focal contractions preceded, and could be uncoupled from, the death and expulsion of infected IECs. In both two-dimensional monolayers and three-dimensional enteroids, multiple infection-elicited contractions coalesced to produce shrinkage of the epithelium as a whole. Monolayers deficient for Caspase-1(-11) or Gasdermin D failed to elicit focal contractions but were still capable of infected IEC death and expulsion. Strikingly, these monolayers lost their integrity to a markedly higher extent than wild-type counterparts. We propose that prompt NAIP/NLRC4/Caspase-1/Gasdermin D/myosin-dependent contractions allow the epithelium to densify its cell packing in infected regions, thereby preventing tissue disintegration due to the subsequent IEC death and expulsion process.
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34
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Ahmed Bhat E, Sajjad N, Ahmad Tantray J, Hor YY, Rather IA. In vitro complex formation of human PYRIN domain-only protein 3 prevented by self-oligomerization of ASC PYD domain. Saudi J Biol Sci 2021; 28:1607-1614. [PMID: 33732046 PMCID: PMC7938106 DOI: 10.1016/j.sjbs.2020.12.049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 12/25/2020] [Accepted: 12/28/2020] [Indexed: 11/30/2022] Open
Abstract
The formation of inflammasome complexes contributes inactivation of inflammatory caspases viz caspase 1, which is generally considered essential for the innate response. Three proteins constituted this inflammasome complex, such as Nod-like receptors (NLRP or AIM2), ASC possessing caspase-recruiting domain, and caspase-1. The ASC proteins comprise two domains, the N-terminal PYD domain responsible for the interaction of various proteins, including PYD only protein 3 (POP3), and the CARD domain for association with other proteins. The PYRIN Domain-Only Protein POP3 negatively regulates responses to DNA virus infection by preventing the ALR inflammasome formation. POP3 directly interacts with ASC, therefore inhibiting ASC recruitment to AIM2-like receptors (ALRs). In the current study, we designed various constructs of the PYRIN Domain-Only Protein 3 (POP3) and ASC PYD domain to find the best-overexpressed construct for biochemical characterization as well as our complex studies. We cloned, purified, and characterized the PYD domain of pyrin only protein 3 and ASC PYD domain under physiological conditions. Our in vitro study clearly shows that the ASC PYD domain of corresponding amino acid 1-96 aa with ease self-oligomerization in physiological buffer conditions, and complex formation of POP3 PYD (1-83 aa) was inhibited by ASC PYD domain. Besides, we purified the PYD of POP3 protein in low and high salt conditions and different pH values for their biochemical characterization. Our results showed that POP3 formed a dimer under normal physiological conditions and was stable under normal buffer conditions; however, the purification in extremely low pH (pH5.0) conditions shows unstable behavior, the high salt conditions (500 mM NaCl) influence the protein aggregation. SDS PAGE arbitrated the homogeneity of the PYD domain of pyrin only protein 3 and ASC PYD domain of corresponding amino acids 1-83 and 1-96, respectively. Furthermore, our native PAGE shows the PYD domain of pyrin; only protein 3 did not form a complex with ASC PYD domain because of oligomerization mediated by the PYD domain.
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Affiliation(s)
- Eijaz Ahmed Bhat
- Life Science Institute, Zhejiang University, Hangzhou, Zhejiang 310058, PR China
| | - Nasreena Sajjad
- Department of Biochemistry, University of Kashmir, Srinagar, 190006, India
| | | | - Yan-Yan Hor
- Department of Biotechnology, College of Life and Applied Sciences, Yeungnam University, Gyeongsan 38541, South Korea
| | - Irfan A. Rather
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
- Center of Excellence for Bionanoscience Research, King Abdulaziz University, Jeddah 21589, Saudi Arabia
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Tenthorey JL, Chavez RA, Thompson TW, Deets KA, Vance RE, Rauch I. NLRC4 inflammasome activation is NLRP3- and phosphorylation-independent during infection and does not protect from melanoma. J Exp Med 2021; 217:151710. [PMID: 32342103 PMCID: PMC7336302 DOI: 10.1084/jem.20191736] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 02/21/2020] [Accepted: 04/01/2020] [Indexed: 12/17/2022] Open
Abstract
The NAIP/NLRC4 inflammasome is a cytosolic sensor of bacteria that activates caspase-1 and initiates potent immune responses. Structural, biochemical, and genetic data demonstrate that NAIP proteins are receptors for bacterial ligands, while NLRC4 is a downstream adaptor that multimerizes with NAIPs to form an inflammasome. NLRC4 has also been proposed to suppress tumor growth, though the underlying mechanism is unknown. Further, NLRC4 is phosphorylated on serine 533, which was suggested to be critical for its function. In the absence of S533 phosphorylation, it was proposed that another inflammasome protein, NLRP3, can induce NLRC4 activation. We generated a new Nlrc4-deficient mouse line and mice with S533D phosphomimetic or S533A nonphosphorylatable NLRC4. Using these models in vivo and in vitro, we fail to observe a requirement for phosphorylation in NLRC4 inflammasome function. Furthermore, we find no role for NLRP3 in NLRC4 function, or for NLRC4 in a model of melanoma. These results clarify our understanding of the mechanism and biological functions of NAIP/NLRC4 activation.
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Affiliation(s)
- Jeannette L Tenthorey
- Molecular and Cell Biology Department, Immunology and Pathogenesis Division, and Cancer Research Laboratory, University of California, Berkeley, Berkeley, CA
| | - Roberto A Chavez
- Molecular and Cell Biology Department, Immunology and Pathogenesis Division, and Cancer Research Laboratory, University of California, Berkeley, Berkeley, CA
| | - Thornton W Thompson
- Molecular and Cell Biology Department, Immunology and Pathogenesis Division, and Cancer Research Laboratory, University of California, Berkeley, Berkeley, CA
| | - Katherine A Deets
- Molecular and Cell Biology Department, Immunology and Pathogenesis Division, and Cancer Research Laboratory, University of California, Berkeley, Berkeley, CA
| | - Russell E Vance
- Molecular and Cell Biology Department, Immunology and Pathogenesis Division, and Cancer Research Laboratory, University of California, Berkeley, Berkeley, CA.,Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA
| | - Isabella Rauch
- Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, OR
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Gram AM, Wright JA, Pickering RJ, Lam NL, Booty LM, Webster SJ, Bryant CE. Salmonella Flagellin Activates NAIP/NLRC4 and Canonical NLRP3 Inflammasomes in Human Macrophages. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2021; 206:631-640. [PMID: 33380493 PMCID: PMC7812056 DOI: 10.4049/jimmunol.2000382] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 11/23/2020] [Indexed: 12/13/2022]
Abstract
Infection of human macrophages with Salmonella enterica serovar Typhimurium (S. Typhimurium) leads to inflammasome activation. Inflammasomes are multiprotein complexes facilitating caspase-1 activation and subsequent gasdermin D-mediated cell death and IL-1β and IL-18 cytokine release. The NAIP/NLRC4 inflammasome is activated by multiple bacterial protein ligands, including flagellin from the flagellum and the needle protein PrgI from the S. Typhimurium type III secretion system. In this study, we show that transfected ultrapure flagellin from S Typhimurium induced cell death and cytokine secretion in THP-1 cells and primary human monocyte-derived macrophages. In THP-1 cells, NAIP/NLRC4 and NLRP3 played redundant roles in inflammasome activation during infection with S. Typhimurium. Knockout of NAIP or NLRC4 in THP-1 cells revealed that flagellin, but not PrgI, now activated the NLRP3 inflammasome through a reactive oxygen species- and/or cathepsin-dependent mechanism that was independent of caspase-4/5 activity. In conclusion, our data suggest that NLRP3 can be activated by flagellin to act as a "safety net" to maintain inflammasome activation under conditions of suboptimal NAIP/NLRC4 activation, as observed in THP-1 cells, possibly explaining the redundant role of NLRP3 and NAIP/NLRC4 during S. Typhimurium infection.
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Affiliation(s)
- Anna M Gram
- Immunology Catalyst Programme, GlaxoSmithKline, Stevenage SG1 2NY, United Kingdom
| | - John A Wright
- Immunology Catalyst Programme, GlaxoSmithKline, Stevenage SG1 2NY, United Kingdom
| | - Robert J Pickering
- Immunology Catalyst Programme, GlaxoSmithKline, Stevenage SG1 2NY, United Kingdom
| | - Nathaniel L Lam
- Immunology Catalyst Programme, GlaxoSmithKline, Stevenage SG1 2NY, United Kingdom
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College, Dublin 2, Ireland; and
| | - Lee M Booty
- Immunology Catalyst Programme, GlaxoSmithKline, Stevenage SG1 2NY, United Kingdom
| | - Steve J Webster
- Department of Veterinary Medicine, The University of Cambridge, Cambridge CB3 OES, United Kingdom
| | - Clare E Bryant
- Immunology Catalyst Programme, GlaxoSmithKline, Stevenage SG1 2NY, United Kingdom;
- Department of Veterinary Medicine, The University of Cambridge, Cambridge CB3 OES, United Kingdom
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Plaza-Díaz J, Álvarez-Mercado AI, Robles-Sánchez C, Navarro-Oliveros M, Morón-Calvente V, Toribio-Castelló S, Sáez-Lara MJ, MacKenzie A, Fontana L, Abadía-Molina F. NAIP expression increases in a rat model of liver mass restoration. J Mol Histol 2021; 52:113-123. [PMID: 33237375 DOI: 10.1007/s10735-020-09928-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 11/13/2020] [Indexed: 11/26/2022]
Abstract
The neuronal apoptosis inhibitory protein (NAIP) is a constituent of the NLRC4 inflammasome, which plays a key role in innate immunity, and an antiapoptotic protein. Recently, we reported the previously undescribed role of NAIP in cell division. The liver is one of the body's most actively regenerative organs. Given the novel mitotic role of NAIP, we examined its expression in hepatic mass restoration. The major liver lobe of Wistar rats was removed, and samples from both newly formed liver tissue, assessed by positive Ki67 immunostaining, and the remnant, intact liver lobes from hepatectomized rats were taken 3 and 7 days after surgery. Naip5 and Naip6 mRNA levels were significantly higher in regenerating hepatic tissue than in intact liver lobe tissue, and this increase was also observed at the protein level. Naip5 and Naip6 mRNA in situ hybridization showed that this increase occurred in the hepatic parenchyma. The histology of the regenerated liver tissue was normal, with the exception of a noticeable deficiency of hepatic lobule central veins. The results of this study suggest the involvement of NAIP in liver mass restoration following partial hepatectomy.
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Affiliation(s)
- Julio Plaza-Díaz
- Department of Biochemistry and Molecular Biology II, School of Pharmacy, University of Granada, 18071, Granada, Spain
- Institute of Nutrition and Food Technology "José Mataix", Biomedical Research Center, Avda. del Conocimiento S/N, Armilla, 18016, Granada, Spain
- Instituto de Investigación Biosanitaria Ibs.GRANADA, Avda. de Madrid 15, 18012, Granada, Spain
- Children's Hospital of Eastern Ontario Research Institute, Ottawa, ON, K1H 8L1, Canada
| | - Ana I Álvarez-Mercado
- Department of Biochemistry and Molecular Biology II, School of Pharmacy, University of Granada, 18071, Granada, Spain
- Institute of Nutrition and Food Technology "José Mataix", Biomedical Research Center, Avda. del Conocimiento S/N, Armilla, 18016, Granada, Spain
- Instituto de Investigación Biosanitaria Ibs.GRANADA, Avda. de Madrid 15, 18012, Granada, Spain
| | - Cándido Robles-Sánchez
- Department of Biochemistry and Molecular Biology II, School of Pharmacy, University of Granada, 18071, Granada, Spain
- Institute of Nutrition and Food Technology "José Mataix", Biomedical Research Center, Avda. del Conocimiento S/N, Armilla, 18016, Granada, Spain
| | - Miguel Navarro-Oliveros
- Instituto de Investigación Biosanitaria Ibs.GRANADA, Avda. de Madrid 15, 18012, Granada, Spain
| | - Virginia Morón-Calvente
- Department of Diabetes. Immunology, Diabetes & Metabolism Research Institute, Beckman Research Institute, City of Hope, Duarte, CA, 91010, USA
| | - Sofía Toribio-Castelló
- IBSAL, IBMCC, University of Salamanca-CSIC, Cancer Research Center, 37007, Salamanca, Spain
| | - María José Sáez-Lara
- Institute of Nutrition and Food Technology "José Mataix", Biomedical Research Center, Avda. del Conocimiento S/N, Armilla, 18016, Granada, Spain
- Instituto de Investigación Biosanitaria Ibs.GRANADA, Avda. de Madrid 15, 18012, Granada, Spain
- Department of Biochemistry and Molecular Biology I, School of Sciences, University of Granada, 18071, Granada, Spain
| | - Alex MacKenzie
- Children's Hospital of Eastern Ontario Research Institute, Ottawa, ON, K1H 8L1, Canada
- Department of Pediatrics, University of Ottawa, Ottawa, ON, K1H 8L1, Canada
| | - Luis Fontana
- Department of Biochemistry and Molecular Biology II, School of Pharmacy, University of Granada, 18071, Granada, Spain
- Institute of Nutrition and Food Technology "José Mataix", Biomedical Research Center, Avda. del Conocimiento S/N, Armilla, 18016, Granada, Spain
- Instituto de Investigación Biosanitaria Ibs.GRANADA, Avda. de Madrid 15, 18012, Granada, Spain
| | - Francisco Abadía-Molina
- Institute of Nutrition and Food Technology "José Mataix", Biomedical Research Center, Avda. del Conocimiento S/N, Armilla, 18016, Granada, Spain.
- Department of Cell Biology, School of Sciences, University of Granada, 18071, Granada, Spain.
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Epithelium-autonomous NAIP/NLRC4 prevents TNF-driven inflammatory destruction of the gut epithelial barrier in Salmonella-infected mice. Mucosal Immunol 2021; 14:615-629. [PMID: 33731826 PMCID: PMC8075861 DOI: 10.1038/s41385-021-00381-y] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 11/26/2020] [Accepted: 01/19/2021] [Indexed: 02/04/2023]
Abstract
The gut epithelium is a critical protective barrier. Its NAIP/NLRC4 inflammasome senses infection by Gram-negative bacteria, including Salmonella Typhimurium (S.Tm) and promotes expulsion of infected enterocytes. During the first ~12-24 h, this reduces mucosal S.Tm loads at the price of moderate enteropathy. It remained unknown how this NAIP/NLRC4-dependent tradeoff would develop during subsequent infection stages. In NAIP/NLRC4-deficient mice, S.Tm elicited severe enteropathy within 72 h, characterized by elevated mucosal TNF (>20 pg/mg) production from bone marrow-derived cells, reduced regeneration, excessive enterocyte loss, and a collapse of the epithelial barrier. TNF-depleting antibodies prevented this destructive pathology. In hosts proficient for epithelial NAIP/NLRC4, a heterogeneous enterocyte death response with both apoptotic and pyroptotic features kept S.Tm loads persistently in check, thereby preventing this dire outcome altogether. Our results demonstrate that immediate and selective removal of infected enterocytes, by locally acting epithelium-autonomous NAIP/NLRC4, is required to avoid a TNF-driven inflammatory hyper-reaction that otherwise destroys the epithelial barrier.
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Fattinger SA, Sellin ME, Hardt WD. Epithelial inflammasomes in the defense against Salmonella gut infection. Curr Opin Microbiol 2020; 59:86-94. [PMID: 33128958 DOI: 10.1016/j.mib.2020.09.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 09/15/2020] [Accepted: 09/22/2020] [Indexed: 02/06/2023]
Abstract
The gut epithelium prevents bacterial access to the host's tissues and coordinates a number of mucosal defenses. Here, we review the function of epithelial inflammasomes in the infected host and focus on their role in defense against Salmonella Typhimurium. This pathogen employs flagella to swim towards the epithelium and a type III secretion system (TTSS) to dock and invade intestinal epithelial cells. Flagella and TTSS components are recognized by the canonical NAIP/NLRC4 inflammasome, while LPS activates the non-canonical Caspase-4/11 inflammasome. The relative contributions of these inflammasomes, the activated cell death pathways and the elicited mucosal defenses are subject to environmental control and appear to change along the infection trajectory. It will be an important future task to explain how this may enable defense against the challenges imposed by diverse bacterial enteropathogens.
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Affiliation(s)
- Stefan A Fattinger
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland; Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Mikael E Sellin
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Wolf-Dietrich Hardt
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland.
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40
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Mitchell PS, Roncaioli JL, Turcotte EA, Goers L, Chavez RA, Lee AY, Lesser CF, Rauch I, Vance RE. NAIP-NLRC4-deficient mice are susceptible to shigellosis. eLife 2020; 9:e59022. [PMID: 33074100 PMCID: PMC7595732 DOI: 10.7554/elife.59022] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 10/16/2020] [Indexed: 12/11/2022] Open
Abstract
Bacteria of the genus Shigella cause shigellosis, a severe gastrointestinal disease that is a major cause of diarrhea-associated mortality in humans. Mice are highly resistant to Shigella and the lack of a tractable physiological model of shigellosis has impeded our understanding of this important human disease. Here, we propose that the differential susceptibility of mice and humans to Shigella is due to mouse-specific activation of the NAIP-NLRC4 inflammasome. We find that NAIP-NLRC4-deficient mice are highly susceptible to oral Shigella infection and recapitulate the clinical features of human shigellosis. Although inflammasomes are generally thought to promote Shigella pathogenesis, we instead demonstrate that intestinal epithelial cell (IEC)-specific NAIP-NLRC4 activity is sufficient to protect mice from shigellosis. In addition to describing a new mouse model of shigellosis, our results suggest that the lack of an inflammasome response in IECs may help explain the susceptibility of humans to shigellosis.
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Affiliation(s)
- Patrick S Mitchell
- Division of Immunology & Pathogenesis, Department of Molecular & Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Justin L Roncaioli
- Division of Immunology & Pathogenesis, Department of Molecular & Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Elizabeth A Turcotte
- Division of Immunology & Pathogenesis, Department of Molecular & Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Lisa Goers
- Department of Microbiology, Harvard Medical SchoolBostonUnited States
- Broad Institute of Harvard and MITCambridgeUnited States
- Department of Medicine, Division of Infectious Diseases, Massachusetts General HospitalBostonUnited States
| | - Roberto A Chavez
- Division of Immunology & Pathogenesis, Department of Molecular & Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Angus Y Lee
- Cancer Research Laboratory, University of California, BerkeleyBerkeleyUnited States
| | - Cammie F Lesser
- Department of Microbiology, Harvard Medical SchoolBostonUnited States
- Broad Institute of Harvard and MITCambridgeUnited States
- Department of Medicine, Division of Infectious Diseases, Massachusetts General HospitalBostonUnited States
| | - Isabella Rauch
- Department of Molecular Microbiology and Immunology, Oregon Health and Science UniversityPortlandUnited States
| | - Russell E Vance
- Division of Immunology & Pathogenesis, Department of Molecular & Cell Biology, University of California, BerkeleyBerkeleyUnited States
- Cancer Research Laboratory, University of California, BerkeleyBerkeleyUnited States
- Immunotherapeutics and Vaccine Research Initiative, University of California, BerkeleyBerkeleyUnited States
- Howard Hughes Medical Institute, University of California, BerkeleyBerkeleyUnited States
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41
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Devi S, Stehlik C, Dorfleutner A. An Update on CARD Only Proteins (COPs) and PYD Only Proteins (POPs) as Inflammasome Regulators. Int J Mol Sci 2020; 21:E6901. [PMID: 32962268 PMCID: PMC7555848 DOI: 10.3390/ijms21186901] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 09/17/2020] [Accepted: 09/17/2020] [Indexed: 12/18/2022] Open
Abstract
Inflammasomes are protein scaffolds required for the activation of caspase-1 and the subsequent release of interleukin (IL)-1β, IL-18, and danger signals, as well as the induction of pyroptotic cell death to restore homeostasis following infection and sterile tissue damage. However, excessive inflammasome activation also causes detrimental inflammatory disease. Therefore, extensive control mechanisms are necessary to prevent improper inflammasome responses and inflammatory disease. Inflammasomes are assembled by sequential nucleated polymerization of Pyrin domain (PYD) and caspase recruitment domain (CARD)-containing inflammasome components. Once polymerization is nucleated, this process proceeds in a self-perpetuating manner and represents a point of no return. Therefore, regulation of this key step is crucial for a controlled inflammasome response. Here, we provide an update on two single domain protein families containing either a PYD or a CARD, the PYD-only proteins (POPs) and CARD-only proteins (COPs), respectively. Their structure allows them to occupy and block access to key protein-protein interaction domains necessary for inflammasome assembly, thereby regulating the threshold of these nucleated polymerization events, and consequently, the inflammatory host response.
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Affiliation(s)
- Savita Devi
- Department of Pathology and Laboratory Medicine, Cedars Sinai, Los Angeles, CA 90048, USA;
| | - Christian Stehlik
- Department of Pathology and Laboratory Medicine, Cedars Sinai, Los Angeles, CA 90048, USA;
- Department of Biomedical Sciences, and Samuel Oschin Comprehensive Cancer Institute, Cedars Sinai, Los Angeles, CA 90048, USA
| | - Andrea Dorfleutner
- Department of Pathology and Laboratory Medicine, Cedars Sinai, Los Angeles, CA 90048, USA;
- Department of Biomedical Sciences, Cedars Sinai, Los Angeles, CA 90048, USA
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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.
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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
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43
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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.
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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.
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44
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Intestinal epithelial NAIP/NLRC4 restricts systemic dissemination of the adapted pathogen Salmonella Typhimurium due to site-specific bacterial PAMP expression. Mucosal Immunol 2020; 13:530-544. [PMID: 31953493 PMCID: PMC7181392 DOI: 10.1038/s41385-019-0247-0] [Citation(s) in RCA: 80] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 11/18/2019] [Accepted: 12/10/2019] [Indexed: 02/07/2023]
Abstract
Inflammasomes can prevent systemic dissemination of enteropathogenic bacteria. As adapted pathogens including Salmonella Typhimurium (S. Tm) have evolved evasion strategies, it has remained unclear when and where inflammasomes restrict their dissemination. Bacterial population dynamics establish that the NAIP/NLRC4 inflammasome specifically restricts S. Tm migration from the gut to draining lymph nodes. This is solely attributable to NAIP/NLRC4 within intestinal epithelial cells (IECs), while S. Tm evades restriction by phagocyte NAIP/NLRC4. NLRP3 and Caspase-11 also fail to restrict S. Tm mucosa traversal, migration to lymph nodes, and systemic pathogen growth. The ability of IECs (not phagocytes) to mount a NAIP/NLRC4 defense in vivo is explained by particularly high NAIP/NLRC4 expression in IECs and the necessity for epithelium-invading S. Tm to express the NAIP1-6 ligands-flagella and type-III-secretion-system-1. Imaging reveals both ligands to be promptly downregulated following IEC-traversal. These results highlight the importance of intestinal epithelial NAIP/NLRC4 in blocking bacterial dissemination in vivo, and explain why this constitutes a uniquely evasion-proof defense against the adapted enteropathogen S. Tm.
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45
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Maeda K, Caldez MJ, Akira S. Innate immunity in allergy. Allergy 2019; 74:1660-1674. [PMID: 30891811 PMCID: PMC6790574 DOI: 10.1111/all.13788] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 02/26/2019] [Accepted: 03/10/2019] [Indexed: 12/13/2022]
Abstract
Innate immune system quickly responds to invasion of microbes and foreign substances through the extracellular and intracellular sensing receptors, which recognize distinctive molecular and structural patterns. The recognition of innate immune receptors leads to the induction of inflammatory and adaptive immune responses by activating downstream signaling pathways. Allergy is an immune-related disease and results from a hypersensitive immune response to harmless substances in the environment. However, less is known about the activation of innate immunity during exposure to allergens. New insights into the innate immune system by sensors and their signaling cascades provide us with more important clues and a framework for understanding allergy disorders. In this review, we will focus on recent advances in the innate immune sensing system.
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Affiliation(s)
- Kazuhiko Maeda
- Laboratory of Host Defense, The World Premier International Research Center Initiative (WPI) Immunology Frontier Research Center (IFReC)Osaka UniversityOsakaJapan
| | - Matias J. Caldez
- Laboratory of Host Defense, The World Premier International Research Center Initiative (WPI) Immunology Frontier Research Center (IFReC)Osaka UniversityOsakaJapan
| | - Shizuo Akira
- Laboratory of Host Defense, The World Premier International Research Center Initiative (WPI) Immunology Frontier Research Center (IFReC)Osaka UniversityOsakaJapan
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46
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Abstract
The inflammasome is a multi-molecular platform crucial to the induction of an inflammatory response to cellular danger. Recognition in the cytoplasm of endogenously and exogenously derived ligands initiates conformational change in sensor proteins, such as NLRP3, that permits the subsequent rapid recruitment of adaptor proteins, like ASC, and the resulting assembly of a large-scale inflammatory signalling platform. The assembly process is driven by sensor-sensor interactions as well as sensor-adaptor and adaptor-adaptor interactions. The resulting complex, which can reach diameters of around 1 micron, has a variable composition and stoichiometry. The inflammasome complex functions as a platform for the proximity induced activation of effector caspases, such as caspase-1 and caspase-8. This ultimately leads to the processing of the inflammatory cytokines pro-IL1β and pro-IL18 into their active forms, along with the cleavage of Gasdermin D, a key activator of cell death via pyroptosis.
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47
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Carpentier SJ, Ni M, Duggan JM, James RG, Cookson BT, Hamerman JA. The signaling adaptor BCAP inhibits NLRP3 and NLRC4 inflammasome activation in macrophages through interactions with Flightless-1. Sci Signal 2019; 12:12/581/eaau0615. [PMID: 31088976 DOI: 10.1126/scisignal.aau0615] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
B cell adaptor for phosphoinositide 3-kinase (PI3K) (BCAP) is a signaling adaptor that activates the PI3K pathway downstream of B cell receptor signaling in B cells and Toll-like receptor (TLR) signaling in macrophages. BCAP binds to the regulatory p85 subunit of class I PI3K and is a large, multidomain protein. We used proteomic analysis to identify other BCAP-interacting proteins in macrophages and found that BCAP specifically associated with the caspase-1 pseudosubstrate inhibitor Flightless-1 and its binding partner leucine-rich repeat flightless-interacting protein 2. Because these proteins inhibit the NLRP3 inflammasome, we investigated the role of BCAP in inflammasome function. Independent of its effects on TLR priming, BCAP inhibited NLRP3- and NLRC4-induced caspase-1 activation, cell death, and IL-1β release from macrophages. Accordingly, caspase-1-dependent clearance of a Yersinia pseudotuberculosis mutant was enhanced in BCAP-deficient mice. Mechanistically, BCAP delayed the recruitment and activation of pro-caspase-1 within the NLRP3/ASC preinflammasome through its association with Flightless-1. Thus, BCAP is a multifunctional signaling adaptor that inhibits key pathogen-sensing pathways in macrophages.
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Affiliation(s)
- Samuel J Carpentier
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
| | - Minjian Ni
- Immunology Program, Benaroya Research Institute, Seattle, WA 98101, USA
| | - Jeffrey M Duggan
- Immunology Program, Benaroya Research Institute, Seattle, WA 98101, USA.,Department of Immunology, University of Washington, Seattle, WA 98109, USA
| | - Richard G James
- Seattle Children's Research Institute, Seattle, WA 98101, USA.,Department of Pediatrics, University of Washington, Seattle, WA 98195, USA
| | - Brad T Cookson
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA.,Department of Laboratory Medicine, University of Washington, Seattle, WA 98195, USA
| | - Jessica A Hamerman
- Immunology Program, Benaroya Research Institute, Seattle, WA 98101, USA. .,Department of Immunology, University of Washington, Seattle, WA 98109, USA
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48
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The Interplay between Salmonella enterica Serovar Typhimurium and the Intestinal Mucosa during Oral Infection. Microbiol Spectr 2019; 7. [PMID: 30953432 DOI: 10.1128/microbiolspec.bai-0004-2019] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Bacterial infection results in a dynamic interplay between the pathogen and its host. The underlying interactions are multilayered, and the cellular responses are modulated by the local environment. The intestine is a particularly interesting tissue regarding host-pathogen interaction. It is densely colonized by commensal microbes and a portal of entry for ingested pathogens. This necessitates constant monitoring of microbial stimuli in order to maintain homeostasis during encounters with benign microbiota and to trigger immune defenses in response to bacterial pathogens. Homeostasis is maintained by physical barriers (the mucus layer and epithelium), chemical defenses (antimicrobial peptides), and innate immune responses (NLRC4 inflammasome), which keep the bacteria from reaching the sterile lamina propria. Intestinal pathogens represent potent experimental tools to probe these barriers and decipher how pathogens can circumvent them. The streptomycin mouse model of oral Salmonella enterica serovar Typhimurium infection provides a well-characterized, robust experimental system for such studies. Strikingly, each stage of the gut tissue infection poses a different set of challenges to the pathogen and requires tight control of virulence factor expression, host response modulation, and cooperation between phenotypic subpopulations. Therefore, successful infection of the intestinal tissue relies on a delicate and dynamic balance between responses of the pathogen and its host. These mechanisms can be deciphered to their full extent only in realistic in vivo infection models.
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49
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Amarante-Mendes GP, Adjemian S, Branco LM, Zanetti LC, Weinlich R, Bortoluci KR. Pattern Recognition Receptors and the Host Cell Death Molecular Machinery. Front Immunol 2018; 9:2379. [PMID: 30459758 PMCID: PMC6232773 DOI: 10.3389/fimmu.2018.02379] [Citation(s) in RCA: 411] [Impact Index Per Article: 68.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 09/25/2018] [Indexed: 12/18/2022] Open
Abstract
Pattern Recognition Receptors (PRRs) are proteins capable of recognizing molecules frequently found in pathogens (the so-called Pathogen-Associated Molecular Patterns—PAMPs), or molecules released by damaged cells (the Damage-Associated Molecular Patterns—DAMPs). They emerged phylogenetically prior to the appearance of the adaptive immunity and, therefore, are considered part of the innate immune system. Signals derived from the engagement of PRRs on the immune cells activate microbicidal and pro-inflammatory responses required to eliminate or, at least, to contain infectious agents. Molecularly controlled forms of cell death are also part of a very ancestral mechanism involved in key aspects of the physiology of multicellular organism, including the elimination of unwanted, damaged or infected cells. Interestingly, each form of cell death has its particular effect on inflammation and on the development of innate and adaptive immune responses. In this review article, we discuss some aspects of the molecular interplay between the cell death machinery and signals initiated by the activation of PRRs by PAMPs and DAMPs.
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Affiliation(s)
- Gustavo P Amarante-Mendes
- Departamento de Imunologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil.,Instituto de Investigação em Imunologia, Instituto Nacional de Ciência e Tecnologia (INCT), São Paulo, Brazil
| | - Sandy Adjemian
- Molecular Signaling and Cell Death Unit, Inflammation Research Center, VIB, Ghent, Belgium.,Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Laura Migliari Branco
- Departamento de Ciências Biológicas, Universidade Federal de São Paulo, Diadema, Brazil.,Centro de Terapia Celular e Molecular (CTC-Mol), Universidade Federal de São Paulo, São Paulo, Brazil
| | - Larissa C Zanetti
- Instituto Israelita de Ensino e Pesquisa, Hospital Israelita Albert Einstein, São Paulo, Brazil
| | - Ricardo Weinlich
- Instituto Israelita de Ensino e Pesquisa, Hospital Israelita Albert Einstein, São Paulo, Brazil
| | - Karina R Bortoluci
- Departamento de Ciências Biológicas, Universidade Federal de São Paulo, Diadema, Brazil.,Centro de Terapia Celular e Molecular (CTC-Mol), Universidade Federal de São Paulo, São Paulo, Brazil
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50
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Cordero MD, Alcocer-Gómez E, Ryffel B. Gain of function mutation and inflammasome driven diseases in human and mouse models. J Autoimmun 2018; 91:13-22. [DOI: 10.1016/j.jaut.2018.03.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 03/22/2018] [Accepted: 03/25/2018] [Indexed: 12/26/2022]
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