1
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Barber MF, Fitzgerald JR. Mechanisms of host adaptation by bacterial pathogens. FEMS Microbiol Rev 2024; 48:fuae019. [PMID: 39003250 PMCID: PMC11308195 DOI: 10.1093/femsre/fuae019] [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: 04/15/2024] [Revised: 07/02/2024] [Accepted: 07/24/2024] [Indexed: 07/15/2024] Open
Abstract
The emergence of new infectious diseases poses a major threat to humans, animals, and broader ecosystems. Defining factors that govern the ability of pathogens to adapt to new host species is therefore a crucial research imperative. Pathogenic bacteria are of particular concern, given dwindling treatment options amid the continued expansion of antimicrobial resistance. In this review, we summarize recent advancements in the understanding of bacterial host species adaptation, with an emphasis on pathogens of humans and related mammals. We focus particularly on molecular mechanisms underlying key steps of bacterial host adaptation including colonization, nutrient acquisition, and immune evasion, as well as suggest key areas for future investigation. By developing a greater understanding of the mechanisms of host adaptation in pathogenic bacteria, we may uncover new strategies to target these microbes for the treatment and prevention of infectious diseases in humans, animals, and the broader environment.
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Affiliation(s)
- Matthew F Barber
- Institute of Ecology and Evolution, University of Oregon, Eugene, OR 97403, United States
- Department of Biology, University of Oregon, Eugene, OR 97403, United States
| | - J Ross Fitzgerald
- The Roslin Institute, University of Edinburgh, Midlothian, EH25 9RG, United Kingdom
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2
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Hua KF, Lin YB, Chiu HW, Wong WT, Ka SM, Wu CH, Lin WY, Wang CC, Hsu CH, Hsu HT, Ho CL, Li LH. Cinnamaldehyde inhibits the NLRP3 inflammasome by preserving mitochondrial integrity and augmenting autophagy in Shigella sonnei-infected macrophages. J Inflamm (Lond) 2024; 21:18. [PMID: 38840105 PMCID: PMC11151564 DOI: 10.1186/s12950-024-00395-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2023] [Accepted: 05/22/2024] [Indexed: 06/07/2024] Open
Abstract
BACKGROUND Worldwide, more than 125 million people are infected with Shigella each year and develop shigellosis. In our previous study, we provided evidence that Shigella sonnei infection triggers activation of the NACHT, LRR, and PYD domain-containing protein 3 (NLRP3) inflammasome in macrophages. NLRP3 inflammasome is responsible for regulating the release of the proinflammatory cytokines interleukin (IL)-1β and IL-18 through the protease caspase-1. Researchers and biotech companies have shown great interest in developing inhibitors of the NLRP3 inflammasome, recognizing it as a promising therapeutic target for several diseases. The leaves of Cinnamomum osmophloeum kaneh, an indigenous tree species in Taiwan, are rich in cinnamaldehyde (CA), a compound present in significant amounts. Our aim is to investigate how CA affects the activation of the NLRP3 inflammasome in S. sonnei-infected macrophages. METHODS Macrophages were infected with S. sonnei, with or without CA. ELISA and Western blotting were employed to detect protein expression or phosphorylation levels. Flow cytometry was utilized to assess H2O2 production and mitochondrial damage. Fluorescent microscopy was used to detect cathepsin B activity and mitochondrial ROS production. Additionally, colony-forming units were employed to measure macrophage phagocytosis and bactericidal activity. RESULTS CA inhibited the NLRP3 inflammasome in S. sonnei-infected macrophages by suppressing caspase-1 activation and reducing IL-1β and IL-18 expression. CA also inhibited pyroptosis by decreasing caspase-11 and Gasdermin D activation. Mechanistically, CA reduced lysosomal damage and enhanced autophagy, while leaving mitochondrial damage, mitogen-activated protein kinase phosphorylation, and NF-κB activation unaffected. Furthermore, CA significantly boosted phagocytosis and the bactericidal activity of macrophages against S. sonnei, while reducing secretion of IL-6 and tumour necrosis factor following infection. CONCLUSION CA shows promise as a nutraceutical for mitigating S. sonnei infection by diminishing inflammation and enhancing phagocytosis and the bactericidal activity of macrophages against S. sonnei.
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Affiliation(s)
- Kuo-Feng Hua
- Department of Biotechnology and Animal Science, National Ilan University, Ilan, Taiwan
- Department of Medical Research, China Medical University Hospital, China Medical University, Taichung, Taiwan
| | - Yu-Bei Lin
- Department of Biotechnology and Animal Science, National Ilan University, Ilan, Taiwan
- Department of Pathology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Hsiao-Wen Chiu
- Department of Biotechnology and Animal Science, National Ilan University, Ilan, Taiwan
| | - Wei-Ting Wong
- Department of Biotechnology and Animal Science, National Ilan University, Ilan, Taiwan
- Taiwan Autoantibody Biobank Initiative, Hualien Tzu Chi Hospital, Hualien, Taiwan
| | - Shuk-Man Ka
- Graduate Institute of Aerospace and Undersea Medicine, Department of Medicine, National Defense Medical Center, Taipei, Taiwan
| | - Chun-Hsien Wu
- Division of Cardiology, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Wen-Yu Lin
- Department of Biotechnology and Animal Science, National Ilan University, Ilan, Taiwan
- Division of Cardiology, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Chien-Chun Wang
- Infectious Disease Division, Linsen, Chinese Medicine and Kunming Branch, Taipei City Hospital, Taipei, Taiwan
- Kunming Prevention and Control Center, Taipei City Hospital, Taipei, Taiwan
| | - Chung-Hua Hsu
- Linsen, Chinese Medicine and Kunming Branch, Taipei City Hospital, Taipei, Taiwan
- Institute of Traditional Medicine, School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Hsien-Ta Hsu
- Division of Neurosurgery, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei City, Taiwan
- School of Medicine, Buddhist Tzu Chi University, Hualien, Taiwan
| | - Chen-Lung Ho
- Division of Wood Cellulose, Taiwan Forestry Research Institute, Taipei, Taiwan
| | - Lan-Hui Li
- Department of Laboratory Medicine, Linsen, Chinese Medicine and Kunming Branch, Taipei City Hospital, Taipei, Taiwan.
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3
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Xiao C, Cao S, Li Y, Luo Y, Liu J, Chen Y, Bai Q, Chen L. Pyroptosis in microbial infectious diseases. Mol Biol Rep 2023; 51:42. [PMID: 38158461 DOI: 10.1007/s11033-023-09078-w] [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: 07/13/2023] [Accepted: 10/30/2023] [Indexed: 01/03/2024]
Abstract
Pyroptosis is a gasdermins-mediated programmed cell death that plays an essential role in immune regulation, and its role in autoimmune disease and cancer has been studied extensively. Increasing evidence shows that various microbial infections can lead to pyroptosis, associated with the occurrence and development of microbial infectious diseases. This study reviews the recent advances in pyroptosis in microbial infection, including bacterial, viral, and fungal infections. We also explore potential therapeutic strategies for treating microbial infection-related diseases by targeting pyroptosis.
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Affiliation(s)
- Cui Xiao
- Department of Public Health Laboratory Sciences, School of Public Health, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
| | - Saihong Cao
- Department of Public Health Laboratory Sciences, School of Public Health, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
- Yiyang Medical College, School of Public Health and Laboratory Medicine, Yiyang, Hunan, 421000, China
| | - Yunfei Li
- Department of Public Health Laboratory Sciences, School of Public Health, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
| | - Yuchen Luo
- Department of Public Health Laboratory Sciences, School of Public Health, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
| | - Jian Liu
- Department of Public Health Laboratory Sciences, School of Public Health, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
| | - Yuyu Chen
- The Affiliated Cancer Hospital of Xiangya School of Medicine, Hunan Cancer Hospital, Central South University Infection-Associated Hemophagocytic Syndrome, Changsha, Hunan, 421000, China
| | - Qinqin Bai
- Department of Public Health Laboratory Sciences, School of Public Health, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China.
| | - Lili Chen
- Department of Public Health Laboratory Sciences, School of Public Health, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China.
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4
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Alphonse N, Odendall C. Animal models of shigellosis: a historical overview. Curr Opin Immunol 2023; 85:102399. [PMID: 37952487 DOI: 10.1016/j.coi.2023.102399] [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: 08/07/2023] [Revised: 10/31/2023] [Accepted: 10/31/2023] [Indexed: 11/14/2023]
Abstract
Shigella spp. are major causative agents of bacillary dysentery, a severe enteric disease characterized by destruction and inflammation of the colonic epithelium accompanied by acute diarrhea, fever, and abdominal pain. Although antibiotics have traditionally been effective, the prevalence of multidrug-resistant strains is increasing, stressing the urgent need for a vaccine. The human-specific nature of shigellosis and the absence of a dependable animal model have posed significant obstacles in understanding Shigella pathogenesis and the host immune response, both of which are crucial for the development of an effective vaccine. Efforts have been made over time to develop a physiological model that mimics the pathological features of the human disease with limited success until the recent development of genetically modified mouse models. In this review, we provide an overview of Shigella pathogenesis and chronicle the historical development of various shigellosis models, emphasizing their strengths and weaknesses.
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Affiliation(s)
- Noémie Alphonse
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, London, UK; Immunoregulation Laboratory, Francis Crick Institute, London, UK.
| | - Charlotte Odendall
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, London, UK.
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5
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Dai Y, Zhou J, Shi C. Inflammasome: structure, biological functions, and therapeutic targets. MedComm (Beijing) 2023; 4:e391. [PMID: 37817895 PMCID: PMC10560975 DOI: 10.1002/mco2.391] [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: 02/24/2023] [Revised: 08/25/2023] [Accepted: 08/29/2023] [Indexed: 10/12/2023] Open
Abstract
Inflammasomes are a group of protein complex located in cytoplasm and assemble in response to a wide variety of pathogen-associated molecule patterns, damage-associated molecule patterns, and cellular stress. Generally, the activation of inflammasomes will lead to maturation of proinflammatory cytokines and pyroptotic cell death, both associated with inflammatory cascade amplification. A sensor protein, an adaptor, and a procaspase protein interact through their functional domains and compose one subunit of inflammasome complex. Under physiological conditions, inflammasome functions against pathogen infection and endogenous dangers including mtROS, mtDNA, and so on, while dysregulation of its activation can lead to unwanted results. In recent years, advances have been made to clarify the mechanisms of inflammasome activation, the structural details of them and their functions (negative/positive) in multiple disease models in both animal models and human. The wide range of the stimuli makes the function of inflammasome diverse and complex. Here, we review the structure, biological functions, and therapeutic targets of inflammasomes, while highlight NLRP3, NLRC4, and AIM2 inflammasomes, which are the most well studied. In conclusion, this review focuses on the activation process, biological functions, and structure of the most well-studied inflammasomes, summarizing and predicting approaches for disease treatment and prevention with inflammasome as a target. We aim to provide fresh insight into new solutions to the challenges in this field.
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Affiliation(s)
- Yali Dai
- Institute of Rocket Force MedicineState Key Laboratory of Trauma and Chemical PoisoningArmy Medical UniversityChongqingChina
| | - Jing Zhou
- Institute of Rocket Force MedicineState Key Laboratory of Trauma and Chemical PoisoningArmy Medical UniversityChongqingChina
- Institute of ImmunologyArmy Medical UniversityChongqingChina
| | - Chunmeng Shi
- Institute of Rocket Force MedicineState Key Laboratory of Trauma and Chemical PoisoningArmy Medical UniversityChongqingChina
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6
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Chai Q, Lei Z, Liu CH. Pyroptosis modulation by bacterial effector proteins. Semin Immunol 2023; 69:101804. [PMID: 37406548 DOI: 10.1016/j.smim.2023.101804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 06/28/2023] [Accepted: 06/29/2023] [Indexed: 07/07/2023]
Abstract
Pyroptosis is a proinflammatory form of programmed cell death featured with membrane pore formation that causes cellular swelling and allows the release of intracellular inflammatory mediators. This cell death process is elicited by the activation of the pore-forming proteins named gasdermins, and is intricately orchestrated by diverse regulatory factors in mammalian hosts to exert a prompt immune response against infections. However, growing evidence suggests that bacterial pathogens have evolved to regulate host pyroptosis for evading immune clearance and establishing progressive infection. In this review, we highlight current understandings of the functional role and regulatory network of pyroptosis in host antibacterial immunity. Thereafter, we further discuss the latest advances elucidating the mechanisms by which bacterial pathogens modulate pyroptosis through adopting their effector proteins to drive infections. A better understanding of regulatory mechanisms underlying pyroptosis at the interface of host-bacterial interactions will shed new light on the pathogenesis of infectious diseases and contribute to the development of promising therapeutic strategies against bacterial pathogens.
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Affiliation(s)
- Qiyao Chai
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
| | - Zehui Lei
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; Savaid Medical School, University of Chinese Academy of Sciences, Beijing 101408, China
| | - Cui Hua Liu
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; Savaid Medical School, University of Chinese Academy of Sciences, Beijing 101408, China.
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7
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Barnett KC, Li S, Liang K, Ting JPY. A 360° view of the inflammasome: Mechanisms of activation, cell death, and diseases. Cell 2023; 186:2288-2312. [PMID: 37236155 PMCID: PMC10228754 DOI: 10.1016/j.cell.2023.04.025] [Citation(s) in RCA: 90] [Impact Index Per Article: 90.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 04/06/2023] [Accepted: 04/17/2023] [Indexed: 05/28/2023]
Abstract
Inflammasomes are critical sentinels of the innate immune system that respond to threats to the host through recognition of distinct molecules, known as pathogen- or damage-associated molecular patterns (PAMPs/DAMPs), or disruptions of cellular homeostasis, referred to as homeostasis-altering molecular processes (HAMPs) or effector-triggered immunity (ETI). Several distinct proteins nucleate inflammasomes, including NLRP1, CARD8, NLRP3, NLRP6, NLRC4/NAIP, AIM2, pyrin, and caspases-4/-5/-11. This diverse array of sensors strengthens the inflammasome response through redundancy and plasticity. Here, we present an overview of these pathways, outlining the mechanisms of inflammasome formation, subcellular regulation, and pyroptosis, and discuss the wide-reaching effects of inflammasomes in human disease.
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Affiliation(s)
- Katherine C Barnett
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
| | - Sirui Li
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Kaixin Liang
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Oral and Craniofacial Biomedicine Program, Adams School of Dentistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Jenny P-Y Ting
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Oral and Craniofacial Biomedicine Program, Adams School of Dentistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
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8
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Gao Y, Yang Y, Wei J, Yue J, Wang Y, Zhang Q, Jin M, Wang R, Yang X, Zhang J, Liu X, Liu L, Zhang Y, Yang R. LNCGM1082-mediated NLRC4 activation drives resistance to bacterial infection. Cell Mol Immunol 2023; 20:475-488. [PMID: 36941318 PMCID: PMC10203293 DOI: 10.1038/s41423-023-00995-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Accepted: 02/23/2023] [Indexed: 03/23/2023] Open
Abstract
The activation of NLRC4 is a major host response against intracellular bacteria infection. However, NLRC4 activation after a host senses diverse stimuli is difficult to understand. Here, we found that the lncRNA LNCGM1082 plays a critical role in the activation of NLRC4. LNCGM1082 in macrophages affects the maturation of interleukin (IL)-1β and pyroptotic cell death only after exposure to an NLRC4 ligand. Similar to NLRC4-/- mice, LNCGM1082-/- mice were highly sensitive to Salmonella Typhimurium (S. T) infection. LNCGM1082 deficiency in mouse or human macrophages inhibited IL-1β maturation and pyroptosis. Mechanistically, LNCGM1082 induced the binding of PKCδ with NLRC4 in both mice and humans. In contrast, NLRC4 did not bind PKCδ in LNCGM1082-/- macrophages. The activity of the lncRNA LNCGM1082 induced by S. T may be mediated through TLR5 in the macrophages of both mice and humans. In summary, our data indicate that TLR5-mediated LNCGM1082 activity can promote the binding of PKCδ with NLRC4 to activate NLRC4 and induce resistance to bacterial infection.
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Affiliation(s)
- Yunhuan Gao
- Department of Immunology, Nankai University School of Medicine and Translational Medicine Institute, Affiliated Tianjin Union Medical Center of Nankai University, Nankai University, Tianjin, 300071, China
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, 300071, China
| | - Yazheng Yang
- Department of Immunology, Nankai University School of Medicine and Translational Medicine Institute, Affiliated Tianjin Union Medical Center of Nankai University, Nankai University, Tianjin, 300071, China
| | - Jianmei Wei
- Department of Immunology, Nankai University School of Medicine and Translational Medicine Institute, Affiliated Tianjin Union Medical Center of Nankai University, Nankai University, Tianjin, 300071, China
| | - Jianmei Yue
- Department of Immunology, Nankai University School of Medicine and Translational Medicine Institute, Affiliated Tianjin Union Medical Center of Nankai University, Nankai University, Tianjin, 300071, China
| | - Ya Wang
- Department of Immunology, Nankai University School of Medicine and Translational Medicine Institute, Affiliated Tianjin Union Medical Center of Nankai University, Nankai University, Tianjin, 300071, China
| | - Qianjing Zhang
- Department of Immunology, Nankai University School of Medicine and Translational Medicine Institute, Affiliated Tianjin Union Medical Center of Nankai University, Nankai University, Tianjin, 300071, China
| | - Mengli Jin
- Department of Immunology, Nankai University School of Medicine and Translational Medicine Institute, Affiliated Tianjin Union Medical Center of Nankai University, Nankai University, Tianjin, 300071, China
| | - Rong Wang
- Department of Immunology, Nankai University School of Medicine and Translational Medicine Institute, Affiliated Tianjin Union Medical Center of Nankai University, Nankai University, Tianjin, 300071, China
| | - Xiaorong Yang
- Department of Immunology, Nankai University School of Medicine and Translational Medicine Institute, Affiliated Tianjin Union Medical Center of Nankai University, Nankai University, Tianjin, 300071, China
| | - Junqi Zhang
- College of Life Science, Nankai University, Tianjin, 300121, China
| | - Xinqi Liu
- College of Life Science, Nankai University, Tianjin, 300121, China
| | - Lin Liu
- China National Center for Bioinformation & Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
| | - Yuan Zhang
- Department of Immunology, Nankai University School of Medicine and Translational Medicine Institute, Affiliated Tianjin Union Medical Center of Nankai University, Nankai University, Tianjin, 300071, China
| | - Rongcun Yang
- Department of Immunology, Nankai University School of Medicine and Translational Medicine Institute, Affiliated Tianjin Union Medical Center of Nankai University, Nankai University, Tianjin, 300071, China.
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, 300071, China.
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Zhao M, Guo J, Gao QH, Wang H, Wang F, Wang ZR, Liu SJ, Deng YJ, Zhao ZW, Zhang YY, Yu WX. Relationship between pyroptosis-mediated inflammation and the pathogenesis of prostate disease. Front Med (Lausanne) 2023; 10:1084129. [PMID: 36744134 PMCID: PMC9892550 DOI: 10.3389/fmed.2023.1084129] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Accepted: 01/03/2023] [Indexed: 01/20/2023] Open
Abstract
The largest solid organ of the male genitalia, the prostate gland, is comprised of a variety of cells such as prostate epithelial cells, smooth muscle cells, fibroblasts, and endothelial cells. Prostate diseases, especially prostate cancer and prostatitis, are often accompanied by acute/chronic inflammatory responses or even cell death. Pyroptosis, a cell death distinct from necrosis and apoptosis, which mediate inflammation may be closely associated with the development of prostate disease. Pyroptosis is characterized by inflammasome activation via pattern recognition receptors (PRR) upon recognition of external stimuli, which is manifested downstream by translocation of gasdermin (GSDM) protein to the membrane to form pores and release of inflammatory factors interleukin (IL)-1β and IL-18, a process that is Caspase-dependent. Over the past number of years, many studies have investigated the role of inflammation in prostate disease and have suggested that pyroptosis may be an important driver. Understanding the precise mechanism is of major consequence for the development of targeted therapeutic strategies. This review summarizes the molecular mechanisms, regulation, and cellular effects of pyroptosis briefly and then discuss the current pyroptosis studies in prostate disease research and the inspiration for us.
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Affiliation(s)
- Ming Zhao
- Graduate School, Beijing University of Chinese Medicine, Beijing, China
| | - Jun Guo
- Department of Andrology, Xiyuan Hospital of China Academy of Chinese Medical Sciences, Beijing, China
| | - Qing-He Gao
- Department of Andrology, Xiyuan Hospital of China Academy of Chinese Medical Sciences, Beijing, China
| | - Hao Wang
- Department of Andrology, Xiyuan Hospital of China Academy of Chinese Medical Sciences, Beijing, China
| | - Fu Wang
- Department of Andrology, Xiyuan Hospital of China Academy of Chinese Medical Sciences, Beijing, China
| | - Zi-Rui Wang
- Graduate School, Beijing University of Chinese Medicine, Beijing, China
| | - Sheng-Jing Liu
- Department of Andrology, Xiyuan Hospital of China Academy of Chinese Medical Sciences, Beijing, China
| | - Ying-Jun Deng
- Graduate School, Beijing University of Chinese Medicine, Beijing, China
| | - Zi-Wei Zhao
- Department of Andrology, Xiyuan Hospital of China Academy of Chinese Medical Sciences, Beijing, China
| | - Yue-Yang Zhang
- Department of Andrology, Wangjing Hospital of China Academy of Chinese Medical Sciences, Beijing, China
| | - Wen-Xiao Yu
- Department of Andrology, Xiyuan Hospital of China Academy of Chinese Medical Sciences, Beijing, China,*Correspondence: Wen-Xiao Yu,
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Vega JL, Gutiérrez C, Rojas M, Güiza J, Sáez JC. Contribution of large-pore channels to inflammation induced by microorganisms. Front Cell Dev Biol 2023; 10:1094362. [PMID: 36699007 PMCID: PMC9868820 DOI: 10.3389/fcell.2022.1094362] [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: 11/10/2022] [Accepted: 12/22/2022] [Indexed: 01/12/2023] Open
Abstract
Plasma membrane ionic channels selectively permeate potassium, sodium, calcium, and chloride ions. However, large-pore channels are permeable to ions and small molecules such as ATP and glutamate, among others. Large-pore channels are structures formed by several protein families with little or no evolutionary linkages including connexins (Cxs), pannexins (Panxs), innexin (Inxs), unnexins (Unxs), calcium homeostasis modulator (CALHMs), and Leucine-rich repeat-containing 8 (LRRC8) proteins. Large-pore channels are key players in inflammatory cell response, guiding the activation of inflammasomes, the release of pro-inflammatory cytokines such as interleukin-1 beta (IL-1ß), and the release of adenosine-5'-triphosphate (ATP), which is considered a danger signal. This review summarizes our current understanding of large-pore channels and their contribution to inflammation induced by microorganisms, virulence factors or their toxins.
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Affiliation(s)
- José L. Vega
- Laboratory of Gap Junctions Proteins and Parasitic Diseases (GaPaL), Instituto Antofagasta, Universidad de Antofagasta, Antofagasta, Chile,Centro de Investigación en Inmunología y Biotecnología Biomédica de Antofagasta (CIIBBA), Universidad de Antofagasta, Antofagasta, Chile,Centro de Fisiología y Medicina de Altura (FIMEDALT), Universidad de Antofagasta, Antofagasta, Chile,*Correspondence: José L. Vega,
| | - Camila Gutiérrez
- Laboratory of Gap Junctions Proteins and Parasitic Diseases (GaPaL), Instituto Antofagasta, Universidad de Antofagasta, Antofagasta, Chile
| | - Mauro Rojas
- Laboratory of Gap Junctions Proteins and Parasitic Diseases (GaPaL), Instituto Antofagasta, Universidad de Antofagasta, Antofagasta, Chile
| | - Juan Güiza
- Laboratory of Gap Junctions Proteins and Parasitic Diseases (GaPaL), Instituto Antofagasta, Universidad de Antofagasta, Antofagasta, Chile
| | - Juan C. Sáez
- Centro Interdisciplinario de Neurociencias de Valparaíso (CINV), Instituto de Neurociencias, Universidad de Valparaíso, Valparaíso, Chile
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Ma Z, Li Z, Jiang R, Li X, Yan K, Zhang N, Lu B, Huang Y, Dibo N, Wu X. Virulence-related gene wx2 of Toxoplasma gondii regulated host immune response via classic pyroptosis pathway. Parasit Vectors 2022; 15:454. [PMID: 36471417 PMCID: PMC9724370 DOI: 10.1186/s13071-022-05502-5] [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: 08/02/2022] [Accepted: 09/16/2022] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Toxoplasma gondii is known as the most successful parasite, which can regulate the host immune response through a variety of ways to achieve immune escape. We previously reported that a novel gene wx2 of T. gondii may be a virulence-related molecule. The objective of this study was to explore the mechanism of wx2 regulating host immune response. METHODS The wx2 knockout strain (RHwx2-/- strain) and complementary strain (RHwx2+/+ strain) were constructed by the CRISPR/Cas9 technique, and the virulence of the wx2 gene was detected and changes in pyroptosis-related molecules were observed. RESULTS Compared with the wild RH and RHwx2+/+ strain groups, the survival time for mice infected with the RHwx2-/- strain was prolonged to a certain extent. The mRNA levels of pyroptosis-related molecules of caspase-1, NLRP3, and GSDMD and et al. in mouse lymphocytes in vivo and RAW267.4 cells in vitro infected with RHwx2-/- strain increased to different degrees, compared with infected with wild RH strain and RHwx2+/+ strain. As with the mRNA level, the protein level of caspase-1, caspase-1 p20, IL-1β, NLRP3, GSDMD-FL, GSDMD-N, and phosphorylation level of NF-κB (p65) were also significantly increased. These data suggest that wx2 may regulate the host immune response through the pyroptosis pathway. In infected RAW264.7 cells at 48 h post-infection, the levels of Th1-type cytokines of IFN-γ, Th2-type cytokines such as IL-13, Th17-type cytokine of IL-17 in cells infected with RHwx2-/- were significantly higher than those of RH and RHwx2+/+ strains, suggesting that the wx2 may inhibit the host's immune response. CONCLUSION wx2 is a virulence related gene of T. gondii, and may be involved in host immune regulation by inhibiting the pyroptosis pathway.
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Affiliation(s)
- Zhenrong Ma
- grid.216417.70000 0001 0379 7164Department of Parasitology, Xiangya School of Basic Medicine, Central South University, Changsha, China
| | - Zhuolin Li
- grid.216417.70000 0001 0379 7164Department of Parasitology, Xiangya School of Basic Medicine, Central South University, Changsha, China
| | - Ruolan Jiang
- grid.216417.70000 0001 0379 7164Department of Parasitology, Xiangya School of Basic Medicine, Central South University, Changsha, China ,grid.284723.80000 0000 8877 7471School of Public Health, Southern Medical University, Guangzhou, China
| | - Xuanwu Li
- grid.216417.70000 0001 0379 7164Department of Parasitology, Xiangya School of Basic Medicine, Central South University, Changsha, China
| | - Kang Yan
- grid.216417.70000 0001 0379 7164Department of Parasitology, Xiangya School of Basic Medicine, Central South University, Changsha, China
| | - Ni Zhang
- grid.216417.70000 0001 0379 7164Department of Parasitology, Xiangya School of Basic Medicine, Central South University, Changsha, China
| | - Bin Lu
- grid.216417.70000 0001 0379 7164Department of Parasitology, Xiangya School of Basic Medicine, Central South University, Changsha, China
| | - Yehong Huang
- grid.216417.70000 0001 0379 7164Department of Parasitology, Xiangya School of Basic Medicine, Central South University, Changsha, China
| | - Nouhoum Dibo
- grid.216417.70000 0001 0379 7164Department of Parasitology, Xiangya School of Basic Medicine, Central South University, Changsha, China
| | - Xiang Wu
- grid.216417.70000 0001 0379 7164Department of Parasitology, Xiangya School of Basic Medicine, Central South University, Changsha, China ,Hunan Provincial Key Lab of Immunology and Transmission Control On Schistosomiasis, Changsha, China
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Chebly H, Marvaud JC, Safa L, Elkak AK, Kobeissy PH, Kansau I, Larrazet C. Clostridioides difficile Flagellin Activates the Intracellular NLRC4 Inflammasome. Int J Mol Sci 2022; 23:ijms232012366. [PMID: 36293218 PMCID: PMC9604438 DOI: 10.3390/ijms232012366] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 10/06/2022] [Accepted: 10/12/2022] [Indexed: 11/06/2022] Open
Abstract
Clostridioides difficile (C. difficile), is a major cause of nosocomial diarrhea and colitis. C. difficile flagellin FliC contributes toxins to gut inflammation by interacting with the immune Toll-like receptor 5 (TLR5) to activate nuclear factor-kappa B (NF-kB) and mitogen-activated protein kinase (MAPK) signaling pathways. Flagella of intracellular pathogens can activate the NLR family CARD domain-containing protein 4 (NLRC4) inflammasome pathway. In this study, we assessed whether flagellin of the extracellular bacterium C. difficile internalizes into epithelial cells and activates the NLRC4 inflammasome. Confocal microscopy showed internalization of recombinant green fluorescent protein (GFP)-FliC into intestinal Caco-2/TC7 cell line. Full-length GFP-FliC activates NLRC4 in Caco-2/TC7 cells in contrast to truncated GFP-FliC lacking the C-terminal region recognized by the inflammasome. FliC induced cleavage of pro-caspase-1 into two subunits, p20 and p10 as well as gasdermin D (GSDMD), suggesting the caspase-1 and NLRC4 inflammasome activation. In addition, colocalization of GFP-FliC and pro-caspase-1 was observed, indicating the FliC-dependent NLRC4 inflammasome activation. Overexpression of the inflammasome-related interleukin (interleukin (IL)-1β, IL-18, and IL-33) encoding genes as well as increasing of the IL-18 synthesis was detected after cell stimulation. Inhibition of I-kappa-B kinase alpha (IKK-α) decreased the FliC-dependent inflammasome interleukin gene expression suggesting a role of the NF-κB pathway in regulating inflammasome. Altogether, these results suggest that FliC internalizes into the Caco-2/TC7 cells and activates the intracellular NLRC4 inflammasome thus contributing to the inflammatory process of C. difficile infection.
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Affiliation(s)
- Hiba Chebly
- Institut Micalis, Université Paris-Saclay, INRAE, AgroParisTech, 91400 Orsay, France
- Health Resources and Products Valorization Laboratory, Faculty of Pharmacy, Lebanese University, Beirut 1102-2801, Lebanon
| | | | - Layale Safa
- Health Resources and Products Valorization Laboratory, Faculty of Pharmacy, Lebanese University, Beirut 1102-2801, Lebanon
| | - Assem Khalil Elkak
- Health Resources and Products Valorization Laboratory, Faculty of Pharmacy, Lebanese University, Beirut 1102-2801, Lebanon
| | - Philippe Hussein Kobeissy
- Department of Natural Sciences, School of Arts and Sciences, Lebanese American University, Beirut 1102-2801, Lebanon
| | - Imad Kansau
- Institut Micalis, Université Paris-Saclay, INRAE, AgroParisTech, 91400 Orsay, France
| | - Cécile Larrazet
- Institut Micalis, Université Paris-Saclay, INRAE, AgroParisTech, 91400 Orsay, France
- Correspondence:
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13
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Activation and manipulation of inflammasomes and pyroptosis during bacterial infections. Biochem J 2022; 479:867-882. [PMID: 35438136 DOI: 10.1042/bcj20220051] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 03/29/2022] [Accepted: 04/04/2022] [Indexed: 12/17/2022]
Abstract
Following detection of pathogen infection and disrupted cellular homeostasis, cells can activate a range of cell death pathways, such as apoptosis, necroptosis and pyroptosis, as part of their defence strategy. The initiation of pro-inflammatory, lytic pyroptosis is controlled by inflammasomes, which respond to a range of cellular perturbations. As is true for many host defence pathways, pathogens have evolved multiple mechanisms to subvert this pathway, many of which have only recently been described. Herein, we will discuss the mechanisms by which inflammasomes sense pathogen invasion and initiate pyroptosis and the effector mechanisms used by pathogens to suppress this pathway and preserve their niche.
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14
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CrkII/Abl phosphorylation cascade is critical for NLRC4 inflammasome activity and is blocked by Pseudomonas aeruginosa ExoT. Nat Commun 2022; 13:1295. [PMID: 35277504 PMCID: PMC8917168 DOI: 10.1038/s41467-022-28967-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 02/22/2022] [Indexed: 11/17/2022] Open
Abstract
Type 3 Secretion System (T3SS) is a highly conserved virulence structure that plays an essential role in the pathogenesis of many Gram-negative pathogenic bacteria, including Pseudomonas aeruginosa. Exotoxin T (ExoT) is the only T3SS effector protein that is expressed in all T3SS-expressing P. aeruginosa strains. Here we show that T3SS recognition leads to a rapid phosphorylation cascade involving Abl / PKCδ / NLRC4, which results in NLRC4 inflammasome activation, culminating in inflammatory responses that limit P. aeruginosa infection in wounds. We further show that ExoT functions as the main anti-inflammatory agent for P. aeruginosa in that it blocks the phosphorylation cascade through Abl / PKCδ / NLRC4 by targeting CrkII, which we further demonstrate to be important for Abl transactivation and NLRC4 inflammasome activation in response to T3SS and P. aeruginosa infection. Pseudomonas aeruginosa secretes the toxin ExoT, which is important for pathogenesis. Here, the authors show that ExoT inhibits NLRC4-dependent inflammatory responses during wound infection.
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15
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High-Throughput CRISPR Screens To Dissect Macrophage- Shigella Interactions. mBio 2021; 12:e0215821. [PMID: 34933448 PMCID: PMC8689513 DOI: 10.1128/mbio.02158-21] [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] [Indexed: 11/20/2022] Open
Abstract
Shigellosis causes most diarrheal deaths worldwide, particularly affecting children. Shigella invades and replicates in the epithelium of the large intestine, eliciting inflammation and tissue destruction. To understand how Shigella rewires macrophages prior to epithelium invasion, we performed genome-wide and focused secondary CRISPR knockout and CRISPR interference (CRISPRi) screens in Shigella flexneri-infected human monocytic THP-1 cells. Knockdown of the Toll-like receptor 1/2 signaling pathway significantly reduced proinflammatory cytokine and chemokine production, enhanced host cell survival, and controlled intracellular pathogen growth. Knockdown of the enzymatic component of the mitochondrial pyruvate dehydrogenase complex enhanced THP-1 cell survival. Small-molecule inhibitors blocking key components of these pathways had similar effects; these were validated with human monocyte-derived macrophages, which closely mimic the in vivo physiological state of macrophages postinfection. High-throughput CRISPR screens can elucidate how S. flexneri triggers inflammation and redirects host pyruvate catabolism for energy acquisition before killing macrophages, pointing to new shigellosis therapies.
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16
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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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Ullah A, Wang MJ, Yang JP, Adu-Gyamfi EA, Czika A, Sah SK, Feng Q, Wang YX. Ovarian inflammatory mRNA profiles of a dehydroepiandrosterone plus high-fat diet-induced polycystic ovary syndrome mouse model. Reprod Biomed Online 2021; 44:791-802. [DOI: 10.1016/j.rbmo.2021.10.024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 10/15/2021] [Accepted: 10/25/2021] [Indexed: 10/19/2022]
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Tyrkalska SD, Candel S, Mulero V. The neutrophil inflammasome. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2021; 115:103874. [PMID: 32987011 DOI: 10.1016/j.dci.2020.103874] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 09/21/2020] [Accepted: 09/21/2020] [Indexed: 06/11/2023]
Abstract
Since inflammasomes were discovered in the early 21st century, knowledge about their biology has multiplied exponentially. These cytosolic multiprotein complexes alert the immune system about the presence of infection or tissue damage, and regulate the subsequent inflammatory responses. As inflammasome dysregulation is increasingly associated with numerous autoinflammatory disorders, there is an urgent need for further research into the inflammasome's involvement in the pathogenesis of such diseases in order to identify novel therapeutic targets and treatments. The zebrafish has become a widely used animal model to study human diseases in recent years, and has already provided relevant findings in the field of inflammasome biology including the identification of new components and pathways. We provide a detailed analysis of current knowledge on neutrophil inflammasome biology and compare its features with those of the better known macrophage inflammasome, focusing on its contribution to innate immunity and its relevance for human health. Importantly, a large body of evidence points to a link between neutrophil inflammasome dysfunction and many neutrophil-mediated human diseases, but the real contribution of the neutrophil inflammasome to the pathogenesis of these disorders is largely unknown. Although neutrophils have remained in the shadow of macrophages and monocytes in the field of inflammasome research since the discovery of these multiprotein platforms, recent studies strongly suggest that the importance of the neutrophil inflammasome has been underestimated.
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Affiliation(s)
- Sylwia D Tyrkalska
- Departamento de Biología Celular e Histología, Facultad de Biología, Universidad de Murcia, Spain; Instituto Murciano de Investigación Biosanitaria (IMIB)-Arrixaca, Murcia, Spain.
| | - Sergio Candel
- Departamento de Biología Celular e Histología, Facultad de Biología, Universidad de Murcia, Spain; Instituto Murciano de Investigación Biosanitaria (IMIB)-Arrixaca, Murcia, Spain.
| | - Victoriano Mulero
- Departamento de Biología Celular e Histología, Facultad de Biología, Universidad de Murcia, Spain; Instituto Murciano de Investigación Biosanitaria (IMIB)-Arrixaca, Murcia, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Spain.
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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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20
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Yang F, Yang Y, Zeng W. Blockade of anti-dsDNA ameliorates systemic lupus erythematosus in MRL/Faslpr mice through ameliorating inflammation via the PKCδ-NLRC4 axis. Biochem Cell Biol 2020; 99:313-321. [PMID: 33064961 DOI: 10.1139/bcb-2020-0265] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Anti-double-stranded DNA (anti-dsDNA) is closely associated with the inflammatory burden in the brain after ischemic stroke. Here, we studied the inflammatory cascade and investigated the mechanisms behind the pro-inflammatory role of dsDNA in systemic lupus erythematosus (SLE). The serum levels of interleukin-1beta (IL-1β) and IL-6 in SLE patients and the corresponding controls were evaluated using ELISA, and the expression level of caspase-1 was evaluated using quantitative real-time polymerase chain reaction (qRT-PCR). We found that the serum levels of IL-1β and IL-6 were increased in the SLE patients. The expression of caspase-1 was upregulated and positively correlated with the levels of pro-inflammatory factors. The level of anti-dsDNA was also elevated and positively correlated with the results for the mean fluorescence intensity (MFI) of caspase-1. Additionally, we evaluated the functions of PRKCD encoding protein kinase c delta (PKCδ) and NLRC4, in vivo, in MRL/Faslpr mice. We found that renal injury was aggravated, and the levels of pro-inflammatory factors were increased in the MRL/Faslpr mice. We also found that increased levels of NLRC4 in the mice exacerbated renal injury and increased the levels of pro-inflammatory factors, whereas inhibition of PKCδ had the opposite results. These findings provide unique perspectives on pathogenesis of SLE and indicate that inhibition of anti-dsDNA could attenuate renal inflammatory burden, representing a promising therapeutic opportunity for SLE.
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Affiliation(s)
- Fan Yang
- Department of Dermatology, the Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710004, Shaanxi, P.R. China.,Department of Plastic Surgery and Burns, Taihe Hospital, Hubei University of Medicine, Shiyan 442000, Hubei, P.R. China
| | - Yinhui Yang
- Department of Plastic Surgery and Burns, Taihe Hospital, Hubei University of Medicine, Shiyan 442000, Hubei, P.R. China
| | - Weihui Zeng
- Department of Dermatology, the Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710004, Shaanxi, P.R. China
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21
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Zhu J, Ma C, Zhu L, Li J, Peng F, Huang L, Luan X. A role for the NLRC4 inflammasome in premature rupture of membrane. PLoS One 2020; 15:e0237847. [PMID: 32833985 PMCID: PMC7446792 DOI: 10.1371/journal.pone.0237847] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 08/04/2020] [Indexed: 11/19/2022] Open
Abstract
PROM is one of the common complications of perinatal period, which seriously threatens the mother and newborn. The purpose of this study was to identify the role of NLRC4 inflammasomes in this process and their underlying mechanisms. We performed high-throughput RNA sequencing of fetal membrane tissue from 3 normal pregnant women and 3 term-premature rupture of fetal membrane (TPROM) patients who met the inclusion criteria, and found that NLRC4 was significantly up-regulated in TPROM patients. An observational study of TPROM patients (PROM group, n = 30) and normal pregnant women (control group, n = 30) was performed at the Xuzhou Maternal and Child Health Hospital affiliated to Xuzhou Medical University from May 2018 to May 2019. The expression of genes involved in inflammasome complex including NLRC1, NLRC3, AIM2, NLRC4, ASC, caspase-1, IL-6, IL-18 and IL-1βwas determined via real-time PCR, immunohistochemistry and immunofluorescence. Measurement of NLRC4 level in serum was conducted by ELISA assay. The results showed that the NLRC4, ASC, caspase-1, IL-1β and IL-18 levels in fetal membrane, placental tissues and maternal serum were markedly higher in the PROM group than that in the control group. In conclusion, NLRC4 is a markedly up-regulated gene in TPROM fetal membrane tissue, suggesting that NLRC4 is involved in the occurrence and development of TPROM; NLRC4 levels in maternal blood serum are closely related to TPROM and have the potential to assist doctors in predicting and diagnosing PROM.
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Affiliation(s)
- Jinming Zhu
- Department of Obstetrics, Xuzhou Maternity and Child Health Care Hospital Affiliated to Xuzhou Medical University, Xuzhou, Jiangsu, China
- * E-mail:
| | - Chunling Ma
- Graduate School, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Lina Zhu
- Department of Obstetrics and Gynecology, Affiliated Huaihai Hospital of Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Juan Li
- Department of Obstetrics, Xuzhou Maternity and Child Health Care Hospital Affiliated to Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Fengyun Peng
- Department of Obstetrics, Xuzhou Maternity and Child Health Care Hospital Affiliated to Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Lei Huang
- Department of Obstetrics, Xuzhou Maternity and Child Health Care Hospital Affiliated to Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Xiaomei Luan
- Department of Obstetrics, Xuzhou Maternity and Child Health Care Hospital Affiliated to Xuzhou Medical University, Xuzhou, Jiangsu, China
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22
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Tuladhar S, Kanneganti TD. NLRP12 in innate immunity and inflammation. Mol Aspects Med 2020; 76:100887. [PMID: 32838963 DOI: 10.1016/j.mam.2020.100887] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 06/01/2020] [Accepted: 07/29/2020] [Indexed: 02/07/2023]
Abstract
Nucleotide-binding leucine-rich repeat-containing proteins, or NOD-like receptors (NLRs), are intracellular innate immune sensors that can regulate several signaling pathways, including MyD88- and TRIF-dependent pathways. In addition to these regulatory roles, some NLRs can assemble into multimeric protein complexes known as inflammasomes. NLRP12 is a member of the NLR family that contains an N-terminal pyrin domain, a central nucleotide-binding domain, and a C-terminal leucine-rich repeat. It has been shown to play a role in forming an inflammasome in response to specific infections, and it can also function as a regulator of inflammatory signaling. During Yersinia pestis or Plasmodium chabaudi infection, NLRP12 induces the release of the inflammasome-dependent cytokines IL-1β and IL-18. These NLRP12-dependent cytokines confer protection against severe infections caused by these pathogens. Conversely, during infection with Salmonella enterica serovar Typhimurium, vesicular stomatitis virus, Klebsiella pneumoniae, or Mycobacterium tuberculosis, and in colonic tumorigenesis, NLRP12 acts as a negative regulator of the NFκB and MAPK signaling pathways. NLRP12 also negatively regulates canonical and non-canonical signaling in T cells and causes exacerbated autoimmune diseases. Furthermore, NLRP12 acts as a central component in maintaining intestinal inflammation and gut homeostasis. Therefore, the ability of NLRP12 to function as an inflammasome or as a negative regulator is context-dependent. In this review, we provide an overview of the NLR family members and summarize recent insights into the roles of NLRP12 as an inflammasome and as a negative regulator.
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Affiliation(s)
- Shraddha Tuladhar
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN, 38105, 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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Nazarian-Samani Z, Sewell RDE, Rafieian-Kopaei M. Inflammasome Signaling and Other Factors Implicated in Atherosclerosis Development and Progression. Curr Pharm Des 2020; 26:2583-2590. [DOI: 10.2174/1381612826666200504115045] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 03/17/2020] [Indexed: 12/20/2022]
Abstract
Chronic inflammation plays an extensive role in the onset and progression of metabolic disorders such
as atherosclerosis, type 2 diabetes, gout and obesity. Atherosclerosis accounts for up to 70% mortality in patients
with type 2 diabetes and is also a chronic condition that causes atrial stenosis due to a lipometabolism imbalance.
The purpose of this article is to consider the inflammatory factors implicated in atherosclerosis and their role in
the development and progression of this vascular disease. The inflammasome signaling pathway is an important
inflammatory mechanism involved in the development of atherosclerosis. The most important inflammasome
pathway in this respect is the NLRP3 inflammasome (Nucleotide-binding oligomerization domain (NOD)-like
receptor with a pyrin domain 3), whose activation leads to the generation of important inflammatory cytokines
including interleukins 1β and 18 (IL-1β and 18). The activities of these mature cytokines and inflammatory factors
produced by other inflammatory pathways lead to arterial inflammation and eventually arterial occlusion,
which can result in life-threatening complications such as myocardial infarction and stroke. Therefore, it is essential
to seek out more precise mechanisms for the activation of inflammasomes and other inflammatory pathways
for the development of therapeutic strategies of atherosclerosis.
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Affiliation(s)
- Zeinab Nazarian-Samani
- Department of Biochemistry, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
| | - Robert D. E. Sewell
- Cardiff School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, CF10 3NB. Wales, United Kingdom
| | - Mahmoud Rafieian-Kopaei
- Medical Plants Research Center, Basic Health Sciences Institute, Shahrekord University of Medical Sciences, Shahrekord, Iran
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25
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Andrade WA, Zamboni DS. NLRC4 biology in immunity and inflammation. J Leukoc Biol 2020; 108:1117-1127. [PMID: 32531834 DOI: 10.1002/jlb.3mr0420-573r] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 04/29/2020] [Accepted: 05/05/2020] [Indexed: 12/14/2022] Open
Abstract
Inflammasomes are cytosolic multiprotein complexes that sense microbial infections or host cell damage, triggering cytokine production and a proinflammatory form of cell death, called pyroptosis. Whereas pyroptosis and cytokine production may often promote host resistance to infections, uncontrolled inflammasome activation leads to autoinflammatory diseases in humans. Among the multiple inflammasomes described, the neuronal apoptosis inhibitory protein/nucleotide-binding domain leucine-rich repeat-containing protein family caspase activation and recruitment domain-containing protein 4 (NLRC4) inflammasome emerged as a critical component for the restriction of bacterial infections. Accordingly, our understanding of this inflammasome advanced remarkably over the last 10 yr, expanding our knowledge about ligand-receptor interaction; cryo-EM structure; and downstream effectors and substrates, such as gasdermin-D, caspase-1, caspase-8, and caspase-7. In this review, we discuss recent advances on the biology of the NLRC4 inflammasome, in terms of structure and activation mechanisms, importance in bacterial and nonbacterial diseases, and the identification of NLRC4 gain-of-function mutations leading to NLRC4-associated autoinflammatory diseases in humans.
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Affiliation(s)
- Warrison A Andrade
- Department of Cell Biology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Ribeirão Preto, São Paulo, Brazil
| | - Dario S Zamboni
- Department of Cell Biology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Ribeirão Preto, São Paulo, Brazil
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Khodavirdipour A, Jamshidi F, Nejad HR, Zandi M, Zarean R. To Study the Anti-cancer Effects of Shigella Flexneri in AspC-1 Pancreatic Cancer Cell Line in Approach to Bax and bcl-2 Genes. J Gastrointest Cancer 2020; 52:593-599. [DOI: 10.1007/s12029-020-00433-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Zheng D, Liwinski T, Elinav E. Inflammasome activation and regulation: toward a better understanding of complex mechanisms. Cell Discov 2020; 6:36. [PMID: 32550001 PMCID: PMC7280307 DOI: 10.1038/s41421-020-0167-x] [Citation(s) in RCA: 454] [Impact Index Per Article: 113.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 04/05/2020] [Indexed: 02/07/2023] Open
Abstract
Inflammasomes are cytoplasmic multiprotein complexes comprising a sensor protein, inflammatory caspases, and in some but not all cases an adapter protein connecting the two. They can be activated by a repertoire of endogenous and exogenous stimuli, leading to enzymatic activation of canonical caspase-1, noncanonical caspase-11 (or the equivalent caspase-4 and caspase-5 in humans) or caspase-8, resulting in secretion of IL-1β and IL-18, as well as apoptotic and pyroptotic cell death. Appropriate inflammasome activation is vital for the host to cope with foreign pathogens or tissue damage, while aberrant inflammasome activation can cause uncontrolled tissue responses that may contribute to various diseases, including autoinflammatory disorders, cardiometabolic diseases, cancer and neurodegenerative diseases. Therefore, it is imperative to maintain a fine balance between inflammasome activation and inhibition, which requires a fine-tuned regulation of inflammasome assembly and effector function. Recently, a growing body of studies have been focusing on delineating the structural and molecular mechanisms underlying the regulation of inflammasome signaling. In the present review, we summarize the most recent advances and remaining challenges in understanding the ordered inflammasome assembly and activation upon sensing of diverse stimuli, as well as the tight regulations of these processes. Furthermore, we review recent progress and challenges in translating inflammasome research into therapeutic tools, aimed at modifying inflammasome-regulated human diseases.
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Affiliation(s)
- Danping Zheng
- Immunology Department, Weizmann Institute of Science, Rehovot, 7610001 Israel
- Department of Gastroenterology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Timur Liwinski
- Immunology Department, Weizmann Institute of Science, Rehovot, 7610001 Israel
- 1st Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Eran Elinav
- Immunology Department, Weizmann Institute of Science, Rehovot, 7610001 Israel
- Cancer-Microbiome Division Deutsches Krebsforschungszentrum (DKFZ), Neuenheimer Feld 280, 69120 Heidelberg, Germany
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Li LH, Chen TL, Chiu HW, Hsu CH, Wang CC, Tai TT, Ju TC, Chen FH, Chernikov OV, Tsai WC, Hua KF. Critical Role for the NLRP3 Inflammasome in Mediating IL-1β Production in Shigella sonnei-Infected Macrophages. Front Immunol 2020; 11:1115. [PMID: 32582195 PMCID: PMC7283925 DOI: 10.3389/fimmu.2020.01115] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Accepted: 05/07/2020] [Indexed: 12/24/2022] Open
Abstract
Shigella is one of the leading bacterial causes of diarrhea worldwide, affecting more than 165 million people annually. Among the serotypes of Shigella, Shigella sonnei is physiologically unique and endemic in human immunodeficiency virus-infected men who have sex with men. The NOD-, LRR-, and pyrin domain-containing protein 3 (NLRP3) inflammasome, a protein complex composed of NLRP3, apoptosis-associated speck-like protein, and caspase-1, recognizes, and responds to pathogen infection and diverse sterile host-derived or environmental danger signals to induce IL-1β and IL-18 production. Although the Shigella flexneri-mediated activation of the NLRP3 inflammasome has been reported, the effect of S. sonnei on NLRP3 inflammasome activation remains unclear. We found that S. sonnei induced IL-1β production through NLRP3-dependent pathways in lipopolysaccharide-primed macrophages. A mechanistic study revealed that S. sonnei induced IL-1β production through P2X7 receptor-mediated potassium efflux, reactive oxygen species generation, lysosomal acidification, and mitochondrial damage. In addition, the phagocytosis of viable S. sonnei was important for IL-1β production. Furthermore, we demonstrated that NLRP3 negatively regulated phagocytosis and the bactericidal activity of macrophages against S. sonnei. These findings provide mechanistic insight into the activation of the NLRP3 inflammasome by S. sonnei in macrophages.
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Affiliation(s)
- Lan-Hui Li
- Department of Laboratory Medicine, Linsen, Chinese Medicine and Kunming Branch, Taipei City Hospital, Taipei, Taiwan.,Department of Pathology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Tzu-Ling Chen
- Department of Laboratory Medicine, Linsen, Chinese Medicine and Kunming Branch, Taipei City Hospital, Taipei, Taiwan.,Department of Pathology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Hsiao-Wen Chiu
- Department of Biotechnology and Animal Science, National Ilan University, Ilan, Taiwan
| | - Chung-Hua Hsu
- Department of Laboratory Medicine, Linsen, Chinese Medicine and Kunming Branch, Taipei City Hospital, Taipei, Taiwan.,Institute of Traditional Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Chien-Chun Wang
- Infectious Disease Division, Linsen, Chinese Medicine and Kunming Branch, Taipei City Hospital, Taipei, Taiwan
| | - Tzu-Ting Tai
- Department of Biotechnology and Animal Science, National Ilan University, Ilan, Taiwan
| | - Tz-Chuen Ju
- Department of Animal Science and Biotechnology, Tunghai University, Taichung, Taiwan
| | - Fang-Hsin Chen
- Department of Medical Imaging and Radiological Sciences, Chang Gung University, Taoyuan, Taiwan
| | - Oleg V Chernikov
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry FEB RAS, Vladivostok, Russia
| | - Wen-Chiuan Tsai
- Department of Pathology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Kuo-Feng Hua
- Department of Pathology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.,Department of Biotechnology and Animal Science, National Ilan University, Ilan, Taiwan.,Department of Medical Research, China Medical University Hospital, China Medical University, Taichung, Taiwan
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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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Sanchez‐Garrido J, Slater SL, Clements A, Shenoy AR, Frankel G. Vying for the control of inflammasomes: The cytosolic frontier of enteric bacterial pathogen-host interactions. Cell Microbiol 2020; 22:e13184. [PMID: 32185892 PMCID: PMC7154749 DOI: 10.1111/cmi.13184] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 01/13/2020] [Accepted: 01/30/2020] [Indexed: 12/13/2022]
Abstract
Enteric pathogen-host interactions occur at multiple interfaces, including the intestinal epithelium and deeper organs of the immune system. Microbial ligands and activities are detected by host sensors that elicit a range of immune responses. Membrane-bound toll-like receptors and cytosolic inflammasome pathways are key signal transducers that trigger the production of pro-inflammatory molecules, such as cytokines and chemokines, and regulate cell death in response to infection. In recent years, the inflammasomes have emerged as a key frontier in the tussle between bacterial pathogens and the host. Inflammasomes are complexes that activate caspase-1 and are regulated by related caspases, such as caspase-11, -4, -5 and -8. Importantly, enteric bacterial pathogens can actively engage or evade inflammasome signalling systems. Extracellular, vacuolar and cytosolic bacteria have developed divergent strategies to subvert inflammasomes. While some pathogens take advantage of inflammasome activation (e.g. Listeria monocytogenes, Helicobacter pylori), others (e.g. E. coli, Salmonella, Shigella, Yersinia sp.) deploy a range of virulence factors, mainly type 3 secretion system effectors, that subvert or inhibit inflammasomes. In this review we focus on inflammasome pathways and their immune functions, and discuss how enteric bacterial pathogens interact with them. These studies have not only shed light on inflammasome-mediated immunity, but also the exciting area of mammalian cytosolic immune surveillance.
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Affiliation(s)
| | | | | | - Avinash R. Shenoy
- Department of Infectious Disease, MRC Centre for Molecular Bacteriology & InfectionImperial College LondonLondonUK
| | - Gad Frankel
- Department of Life SciencesImperial College LondonLondonUK
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Christgen S, Place DE, Kanneganti TD. Toward targeting inflammasomes: insights into their regulation and activation. Cell Res 2020; 30:315-327. [PMID: 32152420 PMCID: PMC7118104 DOI: 10.1038/s41422-020-0295-8] [Citation(s) in RCA: 157] [Impact Index Per Article: 39.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 02/20/2020] [Indexed: 11/27/2022] Open
Abstract
Inflammasomes are multi-component signaling complexes critical to the initiation of pyroptotic cell death in response to invading pathogens and cellular damage. A number of innate immune receptors have been reported to serve as inflammasome sensors. Activation of these sensors leads to the proteolytic activation of caspase-1, a proinflammatory caspase responsible for the cleavage of proinflammatory cytokines interleukin-1β and interleukin-18 and the effector of pyroptotic cell death, gasdermin D. Though crucial to the innate immune response to infection, dysregulation of inflammasome activation can lead to the development of inflammatory diseases, neurodegeneration, and cancer. Therefore, clinical interest in the modulation of inflammasome activation is swiftly growing. As such, it is imperative to develop a mechanistic understanding of the regulation of these complexes. In this review, we divide the regulation of inflammasome activation into three parts. We discuss the transcriptional regulation of inflammasome components and related proteins, the post-translational mechanisms of inflammasome activation, and advances in the understanding of the structural basis of inflammasome activation.
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Affiliation(s)
- Shelbi Christgen
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - David E Place
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
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Imre G. The involvement of regulated cell death forms in modulating the bacterial and viral pathogenesis. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2020; 353:211-253. [PMID: 32381176 PMCID: PMC7102569 DOI: 10.1016/bs.ircmb.2019.12.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Apoptosis, necroptosis and pyroptosis represent three distinct types of regulated cell death forms, which play significant roles in response to viral and bacterial infections. Whereas apoptosis is characterized by cell shrinkage, nuclear condensation, bleb formation and retained membrane integrity, necroptosis and pyroptosis exhibit osmotic imbalance driven cytoplasmic swelling and early membrane damage. These three cell death forms exert distinct immune stimulatory potential. The caspase driven apoptotic cell demise is considered in many circumstances as anti-inflammatory, whereas the two lytic cell death modalities can efficiently trigger immune response by releasing damage associated molecular patterns to the extracellular space. The relevance of these cell death modalities in infections can be best demonstrated by the presence of viral proteins that directly interfere with cell death pathways. Conversely, some pathogens hijack the cell death signaling routes to initiate a targeted attack against the immune cells of the host, and extracellular bacteria can benefit from the destruction of intact extracellular barriers upon cell death induction. The complexity and the crosstalk between these cell death modalities reflect a continuous evolutionary race between pathogens and host. This chapter discusses the current advances in the research of cell death signaling with regard to viral and bacterial infections and describes the network of the cell death initiating molecular mechanisms that selectively recognize pathogen associated molecular patterns.
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Affiliation(s)
- Gergely Imre
- Institute of General Pharmacology and Toxicology, University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany.
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Mukhopadhyay S, Ganguli S, Chakrabarti S. <em>Shigella</em> pathogenesis: molecular and computational insights. AIMS MOLECULAR SCIENCE 2020. [DOI: 10.3934/molsci.2020007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
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Watson JL, Sanchez-Garrido J, Goddard PJ, Torraca V, Mostowy S, Shenoy AR, Clements A. Shigella sonnei O-Antigen Inhibits Internalization, Vacuole Escape, and Inflammasome Activation. mBio 2019; 10:e02654-19. [PMID: 31848280 PMCID: PMC6918081 DOI: 10.1128/mbio.02654-19] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 11/11/2019] [Indexed: 12/04/2022] Open
Abstract
Two Shigella species, Shigella flexneri and Shigella sonnei, cause approximately 90% of bacterial dysentery worldwide. While S. flexneri is the dominant species in low-income countries, S. sonnei causes the majority of infections in middle- and high-income countries. S. flexneri is a prototypic cytosolic bacterium; once intracellular, it rapidly escapes the phagocytic vacuole and causes pyroptosis of macrophages, which is important for pathogenesis and bacterial spread. In contrast, little is known about the invasion, vacuole escape, and induction of pyroptosis during S. sonnei infection of macrophages. We demonstrate here that S. sonnei causes substantially less pyroptosis in human primary monocyte-derived macrophages and THP1 cells. This is due to reduced bacterial uptake and lower relative vacuole escape, which results in fewer cytosolic S. sonnei and hence reduced activation of caspase-1 inflammasomes. Mechanistically, the O-antigen (O-Ag), which in S. sonnei is contained in both the lipopolysaccharide and the capsule, was responsible for reduced uptake and the type 3 secretion system (T3SS) was required for vacuole escape. Our findings suggest that S. sonnei has adapted to an extracellular lifestyle by incorporating multiple layers of O-Ag onto its surface compared to other Shigella species.IMPORTANCE Diarrheal disease remains the second leading cause of death in children under five. Shigella remains a significant cause of diarrheal disease with two species, S. flexneri and S. sonnei, causing the majority of infections. S. flexneri are well known to cause cell death in macrophages, which contributes to the inflammatory nature of Shigella diarrhea. Here, we demonstrate that S. sonnei causes less cell death than S. flexneri due to a reduced number of bacteria present in the cell cytosol. We identify the O-Ag polysaccharide which, uniquely among Shigella spp., is present in two forms on the bacterial cell surface as the bacterial factor responsible. Our data indicate that S. sonnei differs from S. flexneri in key aspects of infection and that more attention should be given to characterization of S. sonnei infection.
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Affiliation(s)
- Jayne L Watson
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Julia Sanchez-Garrido
- Department of Infectious Disease, MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
| | - Philippa J Goddard
- Department of Life Sciences, Imperial College London, London, United Kingdom
- Department of Infectious Disease, MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
| | - Vincenzo Torraca
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Serge Mostowy
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Avinash R Shenoy
- Department of Infectious Disease, MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
| | - Abigail Clements
- Department of Life Sciences, Imperial College London, London, United Kingdom
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Emerging Activators and Regulators of Inflammasomes and Pyroptosis. Trends Immunol 2019; 40:1035-1052. [DOI: 10.1016/j.it.2019.09.005] [Citation(s) in RCA: 169] [Impact Index Per Article: 33.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 09/16/2019] [Accepted: 09/18/2019] [Indexed: 02/08/2023]
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He Y, Xu K, Wang Y, Chao X, Xu B, Wu J, Shen J, Ren W, Hu Y. AMPK as a potential pharmacological target for alleviating LPS-induced acute lung injury partly via NLRC4 inflammasome pathway inhibition. Exp Gerontol 2019; 125:110661. [PMID: 31319131 DOI: 10.1016/j.exger.2019.110661] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2018] [Revised: 06/09/2019] [Accepted: 07/14/2019] [Indexed: 12/12/2022]
Abstract
Old people are spectacularly susceptible to acute lung injury (ALI) and the accompanying complications. An acute aggravated inflammatory response is a characteristic feature of ALI, and inflammasomes play a critical role in the inflammatory response. Metformin has been shown to be an effective anti-inflammatory agent in ALI. However, the mechanism of this regulation still remains poorly understood. In this study, 18- to 19-month-old male mice were treated by intratracheal instillation of lipopolysaccharide (LPS) or PBS with or without metformin pretreatment. We found that the metformin pretreatment alleviated the lung injury and decreased the levels of TNF-a, IL-1β and IL-6 in the bronchoalveolar lavage fluid (BALF) and in lung tissues, as well as the levels of NLRP3, NLRC4 and cleaved caspase-1 associated with LPS-induced ALI in old mice. Furthermore, the in vitro study showed metformin dose-dependently suppressed NLRC4 inflammasome expression. Metformin activated AMPK by phosphorylation; thus, we investigated the role of AMPK in NLRC4 activation. The results demonstrated that the efficacy of metformin was reduced when using the AMPK pharmacological inhibitor compound C or AMPKα1 expression was knocked down in RAW 264.7 cells. In conclusion, our data indicated that metformin may inhibit NLRC4 inflammasome activation in LPS-induced ALI in old mice through AMPK signaling, and further understanding of the AMPK/NLRC4 axis may provide a novel therapeutic strategy for LPS-induced ALI in the future.
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Affiliation(s)
- Yuting He
- Department of Geriatrics, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai 200032, China
| | - Kan Xu
- Department of Geriatrics, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai 200032, China
| | - Yao Wang
- Department of Cardiac Surgery, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai 200032, China
| | - Xin Chao
- Department of Geriatrics, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai 200032, China
| | - Bing'er Xu
- Department of Geriatrics, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai 200032, China
| | - Jiayu Wu
- Department of Geriatrics, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai 200032, China
| | - Jiping Shen
- Department of Geriatrics, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai 200032, China
| | - Weiying Ren
- Department of Geriatrics, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai 200032, China.
| | - Yu Hu
- Department of Geriatrics, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai 200032, China.
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37
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Structural mechanism for NEK7-licensed activation of NLRP3 inflammasome. Nature 2019; 570:338-343. [PMID: 31189953 PMCID: PMC6774351 DOI: 10.1038/s41586-019-1295-z] [Citation(s) in RCA: 442] [Impact Index Per Article: 88.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 05/16/2019] [Indexed: 01/01/2023]
Abstract
The NLRP3 inflammasome can be activated by diverse stimuli, including nigericin, uric acid crystals, amyloid-β fibrils, and extracellular ATP. The mitotic kinase NEK7 licenses NLRP3 inflammasome assembly and activation in the interphase. Here we report a 3.8-Å cryo-electron microscopy structure of inactive human NLRP3 in complex with NEK7. The earring-shaped NLRP3 consists of curved leucine-rich repeat (LRR) and globular NACHT domains, whereas the C-terminal lobe of NEK7 nestles against both NLRP3 domains. Structural recognition between NLRP3 and NEK7 is confirmed by mutagenesis both in vitro and in cells. Modelling of an active NLRP3-NEK7 conformation based on the NLRC4 inflammasome predicts an additional contact between an NLRP3-bound NEK7 and a neighbouring NLRP3. Mutations on this interface abolish the ability of NEK7 or NLRP3 to rescue NLRP3 activation in NEK7KO or NLRP3KO cells. Taken together, these data suggest that NEK7 bridges adjacent NLRP3 subunits with bipartite interactions to mediate NLRP3 inflammasome activation.
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38
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Abstract
ABSTRACT
Shigella
is a genus of Gram-negative enteropathogens that have long been, and continue to be, an important public health concern worldwide. Over the past several decades,
Shigella
spp. have also served as model pathogens in the study of bacterial pathogenesis, and
Shigella flexneri
has become one of the best-studied pathogens on a molecular, cellular, and tissue level. In the arms race between
Shigella
and the host immune system,
Shigella
has developed highly sophisticated mechanisms to subvert host cell processes in order to promote infection, escape immune detection, and prevent bacterial clearance. Here, we give an overview of
Shigella
pathogenesis while highlighting innovative techniques and methods whose application has significantly advanced our understanding of
Shigella
pathogenesis in recent years.
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Abstract
Inflammasomes are multiprotein signaling complexes that are assembled by cytosolic sensors upon the detection of infectious or noxious stimuli. These complexes activate inflammatory caspases to induce host cell death and cytokine secretion and are an essential part of antimicrobial host defense. In this review, I discuss how intracellular bacteria are detected by inflammasomes, how the specific sensing mechanism of each inflammasome receptor restricts the ability of bacteria to evade immune recognition, and how host cell death is used to control bacterial replication in vivo.
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40
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Sandstrom A, Mitchell PS, Goers L, Mu EW, Lesser CF, Vance RE. Functional degradation: A mechanism of NLRP1 inflammasome activation by diverse pathogen enzymes. Science 2019; 364:science.aau1330. [PMID: 30872533 PMCID: PMC6532986 DOI: 10.1126/science.aau1330] [Citation(s) in RCA: 247] [Impact Index Per Article: 49.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 11/05/2018] [Accepted: 03/05/2019] [Indexed: 12/14/2022]
Abstract
Inflammasomes are multiprotein platforms that initiate innate immunity by recruitment and activation of caspase-1. The NLRP1B inflammasome is activated upon direct cleavage by the anthrax lethal toxin protease. However, the mechanism by which cleavage results in NLRP1B activation is unknown. In this study, we find that cleavage results in proteasome-mediated degradation of the amino-terminal domains of NLRP1B, liberating a carboxyl-terminal fragment that is a potent caspase-1 activator. Proteasome-mediated degradation of NLRP1B is both necessary and sufficient for NLRP1B activation. Consistent with our functional degradation model, we identify IpaH7.8, a Shigella flexneri ubiquitin ligase secreted effector, as an enzyme that induces NLRP1B degradation and activation. Our results provide a unified mechanism for NLRP1B activation by diverse pathogen-encoded enzymatic activities.
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Affiliation(s)
- Andrew Sandstrom
- Division of Immunology and Pathogenesis, Department of Molecular & Cell Biology, and Cancer Research Laboratory, University of California, Berkeley, CA, USA.,Howard Hughes Medical Institute, University of California, Berkeley, CA, USA
| | - Patrick S Mitchell
- Division of Immunology and Pathogenesis, Department of Molecular & Cell Biology, and Cancer Research Laboratory, University of California, Berkeley, CA, USA
| | - Lisa Goers
- Department of Microbiology, Harvard Medical School, Boston, MA, USA.,Broad Institute of Harvard and MIT, Cambridge, MA, USA.,Department of Medicine, Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA
| | - Edward W Mu
- Division of Immunology and Pathogenesis, Department of Molecular & Cell Biology, and Cancer Research Laboratory, University of California, Berkeley, CA, USA
| | - Cammie F Lesser
- Department of Microbiology, Harvard Medical School, Boston, MA, USA.,Broad Institute of Harvard and MIT, Cambridge, MA, USA.,Department of Medicine, Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA
| | - Russell E Vance
- Division of Immunology and Pathogenesis, Department of Molecular & Cell Biology, and Cancer Research Laboratory, University of California, Berkeley, CA, USA. .,Howard Hughes Medical Institute, University of California, Berkeley, CA, USA
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41
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Cytosolic Recognition of Microbes and Pathogens: Inflammasomes in Action. Microbiol Mol Biol Rev 2018; 82:82/4/e00015-18. [PMID: 30209070 DOI: 10.1128/mmbr.00015-18] [Citation(s) in RCA: 108] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Infection is a dynamic biological process underpinned by a complex interplay between the pathogen and the host. Microbes from all domains of life, including bacteria, viruses, fungi, and protozoan parasites, have the capacity to cause infection. Infection is sensed by the host, which often leads to activation of the inflammasome, a cytosolic macromolecular signaling platform that mediates the release of the proinflammatory cytokines interleukin-1β (IL-1β) and IL-18 and cleavage of the pore-forming protein gasdermin D, leading to pyroptosis. Host-mediated sensing of the infection occurs when pathogens inject or carry pathogen-associated molecular patterns (PAMPs) into the cytoplasm or induce damage that causes cytosolic liberation of danger-associated molecular patterns (DAMPs) in the host cell. Recognition of PAMPs and DAMPs by inflammasome sensors, including NLRP1, NLRP3, NLRC4, NAIP, AIM2, and Pyrin, initiates a cascade of events that culminate in inflammation and cell death. However, pathogens can deploy virulence factors capable of minimizing or evading host detection. This review presents a comprehensive overview of the mechanisms of microbe-induced activation of the inflammasome and the functional consequences of inflammasome activation in infectious diseases. We also explore the microbial strategies used in the evasion of inflammasome sensing at the host-microbe interaction interface.
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42
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Kesavardhana S, Kanneganti TD. Mechanisms governing inflammasome activation, assembly and pyroptosis induction. Int Immunol 2018; 29:201-210. [PMID: 28531279 DOI: 10.1093/intimm/dxx018] [Citation(s) in RCA: 159] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Accepted: 05/15/2017] [Indexed: 12/11/2022] Open
Abstract
Inflammasomes are multimeric protein complexes that regulate inflammatory responses and pyroptotic cell death to exert host defense against microbes. Intracellular pattern-recognition receptors such as nucleotide-binding domain and leucine-rich repeat receptors (NLRs) and absent in melanoma 2 like receptors (ALRs) assemble the inflammasome complexes in response to pathogens and danger or altered-self signals in the cell. Inflammasome sensors, in association with an adaptor protein-apoptosis-associated speck-like protein containing a caspase-activation and -recruitment domain (ASC)-activate inflammatory caspase-1 to enable the release of inflammatory cytokines and induce cell death, conferring host defense against pathogens. Beyond infectious diseases, the importance of inflammasomes is implicated in a variety of clinical conditions such as auto-inflammatory diseases, neuro-degeneration and metabolic disorders and the development of cancers. Understanding inflammasome activation and its molecular regulation can unveil therapeutic targets for controlling inflammasome-mediated disorders. In this review, we describe recent advances in inflammasome biology and discuss its activation, structural insights into inflammasome assembly and mechanisms for the execution of pyroptosis.
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Affiliation(s)
- Sannula Kesavardhana
- Department of Immunology, St. Jude Children's Research Hospital, MS #351, 262 Danny Thomas Place, Memphis, TN 38105-3678, USA
| | - Thirumala-Devi Kanneganti
- Department of Immunology, St. Jude Children's Research Hospital, MS #351, 262 Danny Thomas Place, Memphis, TN 38105-3678, USA
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43
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Songane M, Khair M, Saleh M. An updated view on the functions of caspases in inflammation and immunity. Semin Cell Dev Biol 2018; 82:137-149. [PMID: 29366812 DOI: 10.1016/j.semcdb.2018.01.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2017] [Revised: 12/21/2017] [Accepted: 01/02/2018] [Indexed: 12/14/2022]
Abstract
The binary classification of mammalian caspases as either apoptotic or inflammatory is now obsolete. Emerging data indicate that all mammalian caspases are intricately involved in the regulation of inflammation and immunity. They participate in embryonic and adult tissue homeostasis, control leukocyte differentiation, activation and effector functions, and mediate innate and adaptive immunity signaling. Caspases also promote host resistance by regulating anti-oxidant defense and pathogen clearance through regulation of phagosomal maturation, actin dynamics and phagosome-lysosome fusion. Beyond apoptosis, they regulate inflammatory cell death, eliciting rapid pyroptosis of infected cells, while inhibiting necroptosis-mediated tissue destruction and chronic inflammation. In this review, we describe the cellular and molecular mechanisms underlying non-apoptotic functions of caspases in inflammation and immunity and provide an updated view of their functions as central regulators of tissue homeostasis and host defense.
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Affiliation(s)
- Mario Songane
- Department of Medicine, McGill University, Montréal, Québec H3G 0B1, Canada
| | - Mostafa Khair
- Department of Medicine, McGill University, Montréal, Québec H3G 0B1, Canada
| | - Maya Saleh
- Department of Medicine, McGill University, Montréal, Québec H3G 0B1, Canada.
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44
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Abstract
Inflammasome signalling is an emerging pillar of innate immunity and has a central role in the regulation of gastrointestinal health and disease. Activation of the inflammasome complex mediates both the release of the pro-inflammatory cytokines IL-1β and IL-18 and the execution of a form of inflammatory cell death known as pyroptosis. In most cases, these mediators of inflammation provide protection against bacterial, viral and protozoal infections. However, unchecked inflammasome activities perpetuate chronic inflammation, which underpins the molecular and pathophysiological basis of gastritis, IBD, upper and lower gastrointestinal cancer, nonalcoholic fatty liver disease and obesity. Studies have also highlighted an inflammasome signature in the maintenance of gut microbiota and gut-brain homeostasis. Harnessing the immunomodulatory properties of the inflammasome could transform clinical practice in the treatment of acute and chronic gastrointestinal and extragastrointestinal diseases. This Review presents an overview of inflammasome biology in gastrointestinal health and disease and describes the value of experimental and pharmacological intervention in the treatment of inflammasome-associated clinical manifestations.
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45
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Suzuki S, Suzuki T, Mimuro H, Mizushima T, Sasakawa C. Shigella hijacks the glomulin-cIAPs-inflammasome axis to promote inflammation. EMBO Rep 2017; 19:89-101. [PMID: 29191979 DOI: 10.15252/embr.201643841] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 10/25/2017] [Accepted: 11/06/2017] [Indexed: 11/09/2022] Open
Abstract
Shigella deploys a unique mechanism to manipulate macrophage pyroptosis by delivering the IpaH7.8 E3 ubiquitin ligase via its type III secretion system. IpaH7.8 ubiquitinates glomulin (GLMN) and elicits its degradation, thereby inducing inflammasome activation and pyroptotic cell death of macrophages. Here, we show that GLMN specifically binds cellular inhibitor of apoptosis proteins 1 and 2 (cIAP1 and cIAP2), members of the inhibitor of apoptosis (IAP) family of RING-E3 ligases, which results in reduced E3 ligase activity, and consequently inflammasome-mediated death of macrophages. Importantly, reducing the levels of GLMN in macrophages via IpaH7.8, or siRNA-mediated knockdown, enhances inflammasome activation in response to infection by Shigella, Salmonella, or Pseudomonas, stimulation with NLRP3 inflammasome activators (including SiO2, alum, or MSU), or stimulation of the AIM2 inflammasome by poly dA:dT GLMN binds specifically to the RING domain of both cIAPs, which inhibits their self-ubiquitination activity. These findings suggest that GLMN is a negative regulator of cIAP-mediated inflammasome activation, and highlight a unique Shigella stratagem to kill macrophages, promoting severe inflammation.
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Affiliation(s)
- Shiho Suzuki
- Division of Bacterial Infection Biology, Institute of Medical Science, The University of Tokyo, Tokyo, Japan .,Department of Bacterial Infection and Host Response, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Toshihiko Suzuki
- Department of Bacterial Infection and Host Response, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Hitomi Mimuro
- Division of Bacteriology, Department of Infectious Diseases Control, International Research Center for Infectious Diseases, Institute of Medical Science, University of Tokyo, Tokyo, Japan.,Department of Infection Microbiology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Tsunehiro Mizushima
- Picobiology Institute, Graduate School of Life Science, University of Hyogo, Hyogo, Japan
| | - Chihiro Sasakawa
- Division of Bacterial Infection Biology, Institute of Medical Science, The University of Tokyo, Tokyo, Japan .,Medical Mycology Research Center, Chiba University, Chiba, Japan.,Nippon Institute for Biological Science, Tokyo, Japan
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46
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Baker PJ, De Nardo D, Moghaddas F, Tran LS, Bachem A, Nguyen T, Hayman T, Tye H, Vince JE, Bedoui S, Ferrero RL, Masters SL. Posttranslational Modification as a Critical Determinant of Cytoplasmic Innate Immune Recognition. Physiol Rev 2017; 97:1165-1209. [DOI: 10.1152/physrev.00026.2016] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Revised: 02/27/2017] [Accepted: 02/28/2017] [Indexed: 12/21/2022] Open
Abstract
Cell surface innate immune receptors can directly detect a variety of extracellular pathogens to which cytoplasmic innate immune sensors are rarely exposed. Instead, within the cytoplasm, the environment is rife with cellular machinery and signaling pathways that are indirectly perturbed by pathogenic microbes to activate intracellular sensors, such as pyrin, NLRP1, NLRP3, or NLRC4. Therefore, subtle changes in key intracellular processes such as phosphorylation, ubiquitination, and other pathways leading to posttranslational protein modification are key determinants of innate immune recognition in the cytoplasm. This concept is critical to establish the “guard hypothesis” whereby otherwise homeostatic pathways that keep innate immune sensors at bay are released in response to alterations in their posttranslational modification status. Originally identified in plants, evidence that a similar guardlike mechanism exists in humans has recently been identified, whereby a mutation that prevents phosphorylation of the innate immune sensor pyrin triggers a dominantly inherited autoinflammatory disease. It is also noteworthy that even when a cytoplasmic innate immune sensor has a direct ligand, such as bacterial peptidoglycan (NOD1 or NOD2), RNA (RIG-I or MDA5), or DNA (cGAS or IFI16), it can still be influenced by posttranslational modification to dramatically alter its response. Therefore, due to their existence in the cytoplasmic milieu, posttranslational modification is a key determinant of intracellular innate immune receptor functionality.
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Affiliation(s)
- Paul J. Baker
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia; Hudson Institute of Medical Research, Monash University, Centre for Innate Immunity and Infectious Diseases, Clayton, Victoria, Australia; The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; and Departments of Medical Biology and of Microbiology and Immunology, The University of Melbourne, Parkville, Australia
| | - Dominic De Nardo
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia; Hudson Institute of Medical Research, Monash University, Centre for Innate Immunity and Infectious Diseases, Clayton, Victoria, Australia; The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; and Departments of Medical Biology and of Microbiology and Immunology, The University of Melbourne, Parkville, Australia
| | - Fiona Moghaddas
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia; Hudson Institute of Medical Research, Monash University, Centre for Innate Immunity and Infectious Diseases, Clayton, Victoria, Australia; The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; and Departments of Medical Biology and of Microbiology and Immunology, The University of Melbourne, Parkville, Australia
| | - Le Son Tran
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia; Hudson Institute of Medical Research, Monash University, Centre for Innate Immunity and Infectious Diseases, Clayton, Victoria, Australia; The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; and Departments of Medical Biology and of Microbiology and Immunology, The University of Melbourne, Parkville, Australia
| | - Annabell Bachem
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia; Hudson Institute of Medical Research, Monash University, Centre for Innate Immunity and Infectious Diseases, Clayton, Victoria, Australia; The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; and Departments of Medical Biology and of Microbiology and Immunology, The University of Melbourne, Parkville, Australia
| | - Tan Nguyen
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia; Hudson Institute of Medical Research, Monash University, Centre for Innate Immunity and Infectious Diseases, Clayton, Victoria, Australia; The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; and Departments of Medical Biology and of Microbiology and Immunology, The University of Melbourne, Parkville, Australia
| | - Thomas Hayman
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia; Hudson Institute of Medical Research, Monash University, Centre for Innate Immunity and Infectious Diseases, Clayton, Victoria, Australia; The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; and Departments of Medical Biology and of Microbiology and Immunology, The University of Melbourne, Parkville, Australia
| | - Hazel Tye
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia; Hudson Institute of Medical Research, Monash University, Centre for Innate Immunity and Infectious Diseases, Clayton, Victoria, Australia; The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; and Departments of Medical Biology and of Microbiology and Immunology, The University of Melbourne, Parkville, Australia
| | - James E. Vince
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia; Hudson Institute of Medical Research, Monash University, Centre for Innate Immunity and Infectious Diseases, Clayton, Victoria, Australia; The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; and Departments of Medical Biology and of Microbiology and Immunology, The University of Melbourne, Parkville, Australia
| | - Sammy Bedoui
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia; Hudson Institute of Medical Research, Monash University, Centre for Innate Immunity and Infectious Diseases, Clayton, Victoria, Australia; The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; and Departments of Medical Biology and of Microbiology and Immunology, The University of Melbourne, Parkville, Australia
| | - Richard L. Ferrero
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia; Hudson Institute of Medical Research, Monash University, Centre for Innate Immunity and Infectious Diseases, Clayton, Victoria, Australia; The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; and Departments of Medical Biology and of Microbiology and Immunology, The University of Melbourne, Parkville, Australia
| | - Seth L. Masters
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia; Hudson Institute of Medical Research, Monash University, Centre for Innate Immunity and Infectious Diseases, Clayton, Victoria, Australia; The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; and Departments of Medical Biology and of Microbiology and Immunology, The University of Melbourne, Parkville, Australia
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47
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Kieser KJ, Kagan JC. Multi-receptor detection of individual bacterial products by the innate immune system. Nat Rev Immunol 2017; 17:376-390. [PMID: 28461704 DOI: 10.1038/nri.2017.25] [Citation(s) in RCA: 116] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The receptors of the innate immune system detect specific microbial ligands to promote effective inflammatory and adaptive immune responses. Although this idea is well appreciated, studies in recent years have highlighted the complexity of innate immune detection, with multiple host receptors recognizing the same microbial ligand. Understanding the collective actions of diverse receptors that recognize common microbial signatures represents a new frontier in the study of innate immunity, and is the focus of this Review. Here, we discuss examples of individual bacterial cell wall components that are recognized by at least two and as many as four different receptors of the innate immune system. These receptors survey the extracellular or cytosolic spaces for their cognate ligands and operate in a complementary manner to induce distinct cellular responses. We further highlight that, despite this genetic diversity in receptors and pathways, common features exist to explain the operation of these receptors. These common features may help to provide unifying organizing principles associated with host defence.
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Affiliation(s)
- Karen J Kieser
- Department of Pediatrics, Harvard Medical School and Division of Gastroenterology, Boston Children's Hospital, Boston, Massachusetts 02115, USA
| | - Jonathan C Kagan
- Department of Pediatrics, Harvard Medical School and Division of Gastroenterology, Boston Children's Hospital, Boston, Massachusetts 02115, USA
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48
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Finn CE, Chong A, Cooper KG, Starr T, Steele-Mortimer O. A second wave of Salmonella T3SS1 activity prolongs the lifespan of infected epithelial cells. PLoS Pathog 2017; 13:e1006354. [PMID: 28426838 PMCID: PMC5413073 DOI: 10.1371/journal.ppat.1006354] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Revised: 05/02/2017] [Accepted: 04/14/2017] [Indexed: 11/19/2022] Open
Abstract
Type III secretion system 1 (T3SS1) is used by the enteropathogen Salmonella enterica serovar Typhimurium to establish infection in the gut. Effector proteins translocated by this system across the plasma membrane facilitate invasion of intestinal epithelial cells. One such effector, the inositol phosphatase SopB, contributes to invasion and mediates activation of the pro-survival kinase Akt. Following internalization, some bacteria escape from the Salmonella-containing vacuole into the cytosol and there is evidence suggesting that T3SS1 is expressed in this subpopulation. Here, we investigated the post-invasion role of T3SS1, using SopB as a model effector. In cultured epithelial cells, SopB-dependent Akt phosphorylation was observed at two distinct stages of infection: during and immediately after invasion, and later during peak cytosolic replication. Single cell analysis revealed that cytosolic Salmonella deliver SopB via T3SS1. Although intracellular replication was unaffected in a SopB deletion mutant, cells infected with ΔsopB demonstrated a lack of Akt phosphorylation, earlier time to death, and increased lysis. When SopB expression was induced specifically in cytosolic Salmonella, these effects were restored to levels observed in WT infected cells, indicating that the second wave of SopB protects this infected population against cell death via Akt activation. Thus, T3SS1 has two, temporally distinct roles during epithelial cell colonization. Additionally, we found that delivery of SopB by cytosolic bacteria was translocon-independent, in contrast to canonical effector translocation across eukaryotic membranes, which requires formation of a translocon pore. This mechanism was also observed for another T3SS1 effector, SipA. These findings reveal the functional and mechanistic adaptability of a T3SS that can be harnessed in different microenvironments.
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Affiliation(s)
- Ciaran E. Finn
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
| | - Audrey Chong
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
| | - Kendal G. Cooper
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
| | - Tregei Starr
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
| | - Olivia Steele-Mortimer
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
- * E-mail:
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49
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Mattock E, Blocker AJ. How Do the Virulence Factors of Shigella Work Together to Cause Disease? Front Cell Infect Microbiol 2017; 7:64. [PMID: 28393050 PMCID: PMC5364150 DOI: 10.3389/fcimb.2017.00064] [Citation(s) in RCA: 138] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 02/21/2017] [Indexed: 01/01/2023] Open
Abstract
Shigella is the major cause of bacillary dysentery world-wide. It is divided into four species, named S. flexneri, S. sonnei, S. dysenteriae, and S. boydii, which are distinct genomically and in their ability to cause disease. Shigellosis, the clinical presentation of Shigella infection, is characterized by watery diarrhea, abdominal cramps, and fever. Shigella's ability to cause disease has been attributed to virulence factors, which are encoded on chromosomal pathogenicity islands and the virulence plasmid. However, information on these virulence factors is not often brought together to create a detailed picture of infection, and how this translates into shigellosis symptoms. Firstly, Shigella secretes virulence factors that induce severe inflammation and mediate enterotoxic effects on the colon, producing the classic watery diarrhea seen early in infection. Secondly, Shigella injects virulence effectors into epithelial cells via its Type III Secretion System to subvert the host cell structure and function. This allows invasion of epithelial cells, establishing a replicative niche, and causes erratic destruction of the colonic epithelium. Thirdly, Shigella produces effectors to down-regulate inflammation and the innate immune response. This promotes infection and limits the adaptive immune response, causing the host to remain partially susceptible to re-infection. Combinations of these virulence factors may contribute to the different symptoms and infection capabilities of the diverse Shigella species, in addition to distinct transmission patterns. Further investigation of the dominant species causing disease, using whole-genome sequencing and genotyping, will allow comparison and identification of crucial virulence factors and may contribute to the production of a pan-Shigella vaccine.
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Affiliation(s)
- Emily Mattock
- Faculty of Biomedical Sciences, Schools of Cellular and Molecular Medicine and Biochemistry, University of Bristol Bristol, UK
| | - Ariel J Blocker
- Faculty of Biomedical Sciences, Schools of Cellular and Molecular Medicine and Biochemistry, University of Bristol Bristol, UK
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Hafner-Bratkovič I. The NLRC4 inflammasome: The pieces of the puzzle are falling into place. ACTA ACUST UNITED AC 2017. [DOI: 10.1515/infl-2017-0002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractInflammasomes are intracellular multiprotein platforms for the activation of inflammatory caspases. As components of the innate immune system, they play an important role in the fight against microbes. However, aberrant inflammasome activation has been implicated in auto-inflammatory syndromes. This review focuses on the NLRC4 inflammasome. This is perhaps not the most extensively studied, yet its mechanism of activation is by far the best understood. The NLRC4 inflammasome is activated by several proteins originating from intracellular bacteria, which are first sensed by receptors of the NAIP family. Activated NAIP binds NLRC4, which further recruits dormant NLRC4 molecules in a prion-like oligomerization event. NLRC4 enables a strong amplification of the signal, providing a fast and robust host response. The review also discusses peculiar NLRC4 inflammasome functions in promoting eicosanoid biosynthesis, actin reorganization, and its roles in autoinflammatory syndromes and sterile inflammation. Finally, the first inflammasome-independent engagement of NLRC4 in suppressing melanoma tumor growth is presented. The emerging roles of NLRC4 in various normal and pathological processes demonstrate that there is still plenty to be learned about the NLRC4 mechanism of activation and downstream functions.
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