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Mascarenhas DP, Zamboni DS. Innate immune responses and monocyte-derived phagocyte recruitment in protective immunity to pathogenic bacteria: insights from Legionella pneumophila. Curr Opin Microbiol 2024; 80:102495. [PMID: 38908045 DOI: 10.1016/j.mib.2024.102495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 04/18/2024] [Accepted: 05/24/2024] [Indexed: 06/24/2024]
Abstract
Legionella species are Gram-negative intracellular bacteria that evolved in soil and freshwater environments, where they infect and replicate within various unicellular protozoa. The primary virulence factor of Legionella is the expression of a type IV secretion system (T4SS), which contributes to the translocation of effector proteins that subvert biological processes of the host cells. Because of its evolution in unicellular organisms, T4SS effector proteins are not adapted to subvert specific mammalian signaling pathways and immunity. Consequently, Legionella pneumophila has emerged as an interesting infection model for investigating immune responses against pathogenic bacteria in multicellular organisms. This review highlights recent advances in our understanding of mammalian innate immunity derived from studies involving L. pneumophila. This includes recent insights into inflammasome-mediated mechanisms restricting bacterial replication in macrophages, mechanisms inducing cell death in response to infection, induction of effector-triggered immunity, activation of specific pulmonary cell types in mammalian lungs, and the protective role of recruiting monocyte-derived cells to infected lungs.
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Affiliation(s)
- Danielle Pa Mascarenhas
- Department of Cell Biology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP 14049-900, Brazil
| | - Dario S Zamboni
- Department of Cell Biology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP 14049-900, Brazil.
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2
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Rakebrandt N, Yassini N, Kolz A, Schorer M, Lambert K, Goljat E, Estrada Brull A, Rauld C, Balazs Z, Krauthammer M, Carballido JM, Peters A, Joller N. Innate acting memory Th1 cells modulate heterologous diseases. Proc Natl Acad Sci U S A 2024; 121:e2312837121. [PMID: 38838013 PMCID: PMC11181110 DOI: 10.1073/pnas.2312837121] [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: 07/26/2023] [Accepted: 05/08/2024] [Indexed: 06/07/2024] Open
Abstract
Through immune memory, infections have a lasting effect on the host. While memory cells enable accelerated and enhanced responses upon rechallenge with the same pathogen, their impact on susceptibility to unrelated diseases is unclear. We identify a subset of memory T helper 1 (Th1) cells termed innate acting memory T (TIA) cells that originate from a viral infection and produce IFN-γ with innate kinetics upon heterologous challenge in vivo. Activation of memory TIA cells is induced in response to IL-12 in combination with IL-18 or IL-33 but is TCR independent. Rapid IFN-γ production by memory TIA cells is protective in subsequent heterologous challenge with the bacterial pathogen Legionella pneumophila. In contrast, antigen-independent reactivation of CD4+ memory TIA cells accelerates disease onset in an autoimmune model of multiple sclerosis. Our findings demonstrate that memory Th1 cells can acquire additional TCR-independent functionality to mount rapid, innate-like responses that modulate susceptibility to heterologous challenges.
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Affiliation(s)
- Nikolas Rakebrandt
- Institute of Experimental Immunology, University of Zurich, 8057Zurich, Switzerland
| | - Nima Yassini
- Institute of Experimental Immunology, University of Zurich, 8057Zurich, Switzerland
- Department of Quantitative Biomedicine, University of Zurich, 8057Zurich, Switzerland
| | - Anna Kolz
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians-Universität München, 82152Planegg, Germany
| | - Michelle Schorer
- Institute of Experimental Immunology, University of Zurich, 8057Zurich, Switzerland
| | - Katharina Lambert
- Institute of Experimental Immunology, University of Zurich, 8057Zurich, Switzerland
| | - Eva Goljat
- Department of Quantitative Biomedicine, University of Zurich, 8057Zurich, Switzerland
| | - Anna Estrada Brull
- Department of Quantitative Biomedicine, University of Zurich, 8057Zurich, Switzerland
| | - Celine Rauld
- Novartis Biomedical Research, 4002Basel, Switzerland
| | - Zsolt Balazs
- Department of Quantitative Biomedicine, University of Zurich, 8057Zurich, Switzerland
| | - Michael Krauthammer
- Department of Quantitative Biomedicine, University of Zurich, 8057Zurich, Switzerland
| | | | - Anneli Peters
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians-Universität München, 82152Planegg, Germany
- Biomedical Center, Faculty of Medicine, Ludwig-Maximilians-Universität München, 82152Planegg, Germany
| | - Nicole Joller
- Institute of Experimental Immunology, University of Zurich, 8057Zurich, Switzerland
- Department of Quantitative Biomedicine, University of Zurich, 8057Zurich, Switzerland
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3
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Oberkircher LM, Scheiding VM, Rafeld HL, Hanssen E, Hansen JN, Fleischmann MJ, Kessler N, Pitsch D, Wachten D, Kastenmüller W, Brown AS, Hartland EL, van Driel IR, Ng GZ, Garbi N. Opposing roles of resident and infiltrating immune cells in the defense against Legionella longbeachae via IL-18R/IFN-γ/ROS axis in mice. Mucosal Immunol 2024:S1933-0219(24)00042-4. [PMID: 38750967 DOI: 10.1016/j.mucimm.2024.05.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Revised: 04/30/2024] [Accepted: 05/07/2024] [Indexed: 07/21/2024]
Abstract
The immune response against Legionella longbeachae, a causative agent of the often-fatal Legionnaires' pneumonia, is poorly understood. Here, we investigated the specific roles of tissue-resident alveolar macrophages (AMs) and infiltrating phagocytes during infection with this pathogen. AMs were the predominant cell type that internalized bacteria 1 day after infection. A total of 3 and 5 days after infection, AM numbers were greatly reduced, whereas there was an influx of neutrophils and, later, monocyte-derived cells (MCs) into lung tissue. AMs carried greater numbers of viable L. longbeachae than neutrophils and MCs, which correlated with a higher capacity of L. longbeachae to translocate bacterial effector proteins required for bacterial replication into the AM cytosol. Cell ablation experiments demonstrated that AM promoted infection, whereas neutrophils and MC were required for efficient bacterial clearance. Interleukin (IL)-18 was important for interferon-γ production by IL-18R+ natural killer cells and T cells, which, in turn, stimulated reactive oxygen species-mediated bactericidal activity in neutrophils, resulting in the restriction of L. longbeachae infection. Ciliated bronchiolar epithelial cells also expressed IL-18R but did not play a role in IL-18-mediated L. longbeachae clearance. Our results have identified opposing innate functions of tissue-resident and infiltrating immune cells during L. longbeachae infection that may be manipulated to improve protective responses.
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Affiliation(s)
- Lara M Oberkircher
- Institute of Molecular Medicine and Experimental Immunology, Faculty of Medicine, University of Bonn, Bonn, Germany; Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, Australia; Department of Biochemistry and Pharmacology, University of Melbourne, Melbourne, Australia; Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, Australia; Department of Microbiology and Immunology, University of Melbourne, Melbourne, Australia
| | - Victoria M Scheiding
- Institute of Molecular Medicine and Experimental Immunology, Faculty of Medicine, University of Bonn, Bonn, Germany; Department of Biochemistry and Pharmacology, University of Melbourne, Melbourne, Australia; Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, Australia
| | - H Linda Rafeld
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, Australia; Life & Medical-Sciences Institute, University of Bonn, Bonn, Germany
| | - Eric Hanssen
- Department of Biochemistry and Pharmacology, University of Melbourne, Melbourne, Australia; Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, Australia; Ian Holmes Imaging Centre, University of Melbourne, Melbourne, Australia
| | - Jan N Hansen
- Institute of Innate Immunity, Faculty of Medicine, University of Bonn, Bonn, Germany
| | - Markus J Fleischmann
- Institute of Molecular Medicine and Experimental Immunology, Faculty of Medicine, University of Bonn, Bonn, Germany; Department of Biochemistry and Pharmacology, University of Melbourne, Melbourne, Australia; Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, Australia
| | - Nina Kessler
- Institute of Molecular Medicine and Experimental Immunology, Faculty of Medicine, University of Bonn, Bonn, Germany
| | - David Pitsch
- Institute of Molecular Medicine and Experimental Immunology, Faculty of Medicine, University of Bonn, Bonn, Germany
| | - Dagmar Wachten
- Institute of Innate Immunity, Faculty of Medicine, University of Bonn, Bonn, Germany
| | - Wolfgang Kastenmüller
- Würzburg Institute of Systems Immunology, Max Planck Research Group at the Julius-Maximilians-Universität Würzburg, Würzburg, Germany
| | - Andrew S Brown
- Department of Biochemistry and Pharmacology, University of Melbourne, Melbourne, Australia; Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, Australia
| | - Elizabeth L Hartland
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, Australia; Department of Microbiology and Immunology, University of Melbourne, Melbourne, Australia; Department of Molecular and Translational Science, Monash University, Clayton, Australia
| | - Ian R van Driel
- Department of Biochemistry and Pharmacology, University of Melbourne, Melbourne, Australia; Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, Australia
| | - Garrett Z Ng
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, Australia; Department of Biochemistry and Pharmacology, University of Melbourne, Melbourne, Australia; Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, Australia; Department of Molecular and Translational Science, Monash University, Clayton, Australia
| | - Natalio Garbi
- Institute of Molecular Medicine and Experimental Immunology, Faculty of Medicine, University of Bonn, Bonn, Germany.
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4
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van der Geest R, Fan H, Peñaloza HF, Bain WG, Xiong Z, Kohli N, Larson E, Sullivan MLG, Franks JM, Stolz DB, Ito R, Chen K, Doi Y, Harriff MJ, Lee JS. Phagocytosis is a primary determinant of pulmonary clearance of clinical Klebsiella pneumoniae isolates. Front Cell Infect Microbiol 2023; 13:1150658. [PMID: 37056705 PMCID: PMC10086180 DOI: 10.3389/fcimb.2023.1150658] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 03/16/2023] [Indexed: 03/30/2023] Open
Abstract
Introduction Klebsiella pneumoniae (Kp) is a common cause of hospital-acquired pneumonia. Although previous studies have suggested that evasion of phagocytic uptake is a virulence determinant of Kp, few studies have examined phagocytosis sensitivity in clinical Kp isolates. Methods We screened 19 clinical respiratory Kp isolates that were previously assessed for mucoviscosity for their sensitivity to macrophage phagocytic uptake, and evaluated phagocytosis as a functional correlate of in vivo Kp pathogenicity. Results The respiratory Kp isolates displayed heterogeneity in the susceptibility to macrophage phagocytic uptake, with 14 out of 19 Kp isolates displaying relative phagocytosis-sensitivity compared to the reference Kp strain ATCC 43816, and 5 out of 19 Kp isolates displaying relative phagocytosis-resistance. Intratracheal infection with the non-mucoviscous phagocytosis-sensitive isolate S17 resulted in a significantly lower bacterial burden compared to infection with the mucoviscous phagocytosis-resistant isolate W42. In addition, infection with S17 was associated with a reduced inflammatory response, including reduced bronchoalveolar lavage fluid (BAL) polymorphonuclear (PMN) cell count, and reduced BAL TNF, IL-1β, and IL-12p40 levels. Importantly, host control of infection with the phagocytosis-sensitive S17 isolate was impaired in alveolar macrophage (AM)-depleted mice, whereas AM-depletion had no significant impact on host defense against infection with the phagocytosis-resistant W42 isolate. Conclusion Altogether, these findings show that phagocytosis is a primary determinant of pulmonary clearance of clinical Kp isolates.
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Affiliation(s)
- Rick van der Geest
- Acute Lung Injury Center of Excellence, Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Hongye Fan
- Acute Lung Injury Center of Excellence, Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Hernán F. Peñaloza
- Acute Lung Injury Center of Excellence, Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - William G. Bain
- Acute Lung Injury Center of Excellence, Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
- Veterans Affairs (VA) Pittsburgh Health Care System, Pittsburgh, PA, United States
| | - Zeyu Xiong
- Acute Lung Injury Center of Excellence, Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Naina Kohli
- Acute Lung Injury Center of Excellence, Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Emily Larson
- Veterans Affairs (VA) Portland Health Care System, Portland, OR, United States
| | - Mara L. G. Sullivan
- Department of Cell Biology, Center for Biologic Imaging, University of Pittsburgh, Pittsburgh, PA, United States
| | - Jonathan M. Franks
- Department of Cell Biology, Center for Biologic Imaging, University of Pittsburgh, Pittsburgh, PA, United States
| | - Donna B. Stolz
- Department of Cell Biology, Center for Biologic Imaging, University of Pittsburgh, Pittsburgh, PA, United States
| | - Ryota Ito
- Department of Respiratory Medicine, Japanese Red Cross Aichi Medical Center Nagoya Daiichi Hospital, Nagoya, Japan
| | - Kong Chen
- Acute Lung Injury Center of Excellence, Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Yohei Doi
- Division of Infectious Diseases, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
- Departments of Microbiology and Infectious Diseases, Fujita Health University, Toyoake, Japan
| | - Melanie J. Harriff
- Veterans Affairs (VA) Portland Health Care System, Portland, OR, United States
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, Oregon Health State University, Portland, OR, United States
| | - Janet S. Lee
- Acute Lung Injury Center of Excellence, Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
- Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, United States
- Division of Pulmonary and Critical Care Medicine, Washington University in St. Louis, St. Louis, MO, United States
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Fleischmann M, Jarnicki AG, Brown AS, Yang C, Anderson GP, Garbi N, Hartland EL, van Driel IR, Ng GZ. Cigarette smoke depletes alveolar macrophages and delays clearance of Legionella pneumophila. Am J Physiol Lung Cell Mol Physiol 2023; 324:L373-L384. [PMID: 36719079 PMCID: PMC10026984 DOI: 10.1152/ajplung.00268.2022] [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: 08/24/2022] [Revised: 12/23/2022] [Accepted: 01/25/2023] [Indexed: 02/01/2023] Open
Abstract
Legionella pneumophila is the main etiological agent of Legionnaires' disease, a severe bacterial pneumonia. L. pneumophila is initially engulfed by alveolar macrophages (AMs) and subvert normal cellular functions to establish a replicative vacuole. Cigarette smokers are particularly susceptible to developing Legionnaires' disease and other pulmonary infections; however, little is known about the cellular mechanisms underlying this susceptibility. To investigate this, we used a mouse model of acute cigarette smoke exposure to examine the immune response to cigarette smoke and subsequent L. pneumophila infection. Contrary to previous reports, we show that cigarette smoke exposure alone causes a significant depletion of AMs using enzymatic digestion to extract cells, or via imaging intact lung lobes by light-sheet microscopy. Furthermore, treatment of mice deficient in specific types of cell death with smoke suggests that NLRP3-driven pyroptosis is a contributor to smoke-induced death of AMs. After infection, smoke-exposed mice displayed increased pulmonary L. pneumophila loads and developed more severe disease compared with air-exposed controls. We tested if depletion of AMs was related to this phenotype by directly depleting them with clodronate liposomes and found that this also resulted in increased L. pneumophila loads. In summary, our results showed that cigarette smoke depleted AMs from the lung and that this likely contributed to more severe Legionnaires' disease. Furthermore, the role of AMs in L. pneumophila infection is more nuanced than simply providing a replicative niche, and our studies suggest they play a major role in bacterial clearance.
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Affiliation(s)
- Markus Fleischmann
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria, Australia
- Institute for Experimental Immunology, University Hospital Bonn, University of Bonn, Bonn, Germany
| | - Andrew G Jarnicki
- Lung Health Research Centre, Department of Biochemistry and Pharmacology, University of Melbourne, Parkville, Victoria, Australia
| | - Andrew S Brown
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria, Australia
| | - Chao Yang
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Parkville, Victoria, Australia
| | - Gary P Anderson
- Lung Health Research Centre, Department of Biochemistry and Pharmacology, University of Melbourne, Parkville, Victoria, Australia
| | - Natalio Garbi
- Institute for Experimental Immunology, University Hospital Bonn, University of Bonn, Bonn, Germany
| | - Elizabeth L Hartland
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Parkville, Victoria, Australia
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, Victoria, Australia
- Department of Molecular and Translational Science, Monash University, Clayton, Victoria, Australia
| | - Ian R van Driel
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria, Australia
| | - Garrett Z Ng
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria, Australia
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, Victoria, Australia
- Department of Molecular and Translational Science, Monash University, Clayton, Victoria, Australia
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6
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Ataide MA, Manin GZ, Oliveira SS, Guerra RO, Zamboni DS. Inflammasome activation and CCR2-mediated monocyte-derived dendritic cell recruitment restrict Legionella pneumophila infection. Eur J Immunol 2023; 53:e2249985. [PMID: 36427489 DOI: 10.1002/eji.202249985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 09/22/2022] [Accepted: 11/24/2022] [Indexed: 11/27/2022]
Abstract
Flagellin-induced NAIP/NLRC4 inflammasome activation and pyroptosis are critical events restricting Legionella pneumophila infection. However, the cellular and molecular dynamics of the in vivo responses against this bacterium are still unclear. We have found temporal coordination of two independent innate immunity pathways in controlling Legionella infection, the inflammasome activation and the CCR2-mediated Mo-DC recruitment. Inflammasome activation was an important player at the early stage of infection by lowering the numbers of bacteria for an efficient bacterial clearance conferred by the Mo-DC at the late stage of the infection. Mo-DC emergence highly depended on CCR2-signaling and dispensed inflammasome activation and pyroptosis. Also, Mo-DC compartment did not rely on the inflammasome machinery to deliver proper immune responses and was the most abundant cytokine-producing among the monocyte-derived cells in the infected lung. Importantly, when the CCR2- and NLRC4-dependent axes of response were simultaneously ablated, we observed an aggravated bacterial burden in the lung of infected mice. Taken together, we showed that inflammasome activation and CCR2-mediated immune response interplay in distinct pathways to restrict pulmonary bacterial infection. These findings extend our understanding of the in vivo integration and cooperation of different innate immunity arms in controlling infectious agents.
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Affiliation(s)
- Marco A Ataide
- Department of Cell Biology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Graziele Z Manin
- Department of Cell Biology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Samuel S Oliveira
- Department of Cell Biology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Rhanoica O Guerra
- Department of Cell Biology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Dario S Zamboni
- Department of Cell Biology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
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7
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Yang JL, Li D, Zhan XY. Concept about the Virulence Factor of Legionella. Microorganisms 2022; 11:microorganisms11010074. [PMID: 36677366 PMCID: PMC9867486 DOI: 10.3390/microorganisms11010074] [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: 11/30/2022] [Revised: 12/23/2022] [Accepted: 12/23/2022] [Indexed: 12/29/2022] Open
Abstract
Pathogenic species of Legionella can infect human alveolar macrophages through Legionella-containing aerosols to cause a disease called Legionellosis, which has two forms: a flu-like Pontiac fever and severe pneumonia named Legionnaires' disease (LD). Legionella is an opportunistic pathogen that frequently presents in aquatic environments as a biofilm or protozoa parasite. Long-term interaction and extensive co-evolution with various genera of amoebae render Legionellae pathogenic to infect humans and also generate virulence differentiation and heterogeneity. Conventionally, the proteins involved in initiating replication processes and human macrophage infections have been regarded as virulence factors and linked to pathogenicity. However, because some of the virulence factors are associated with the infection of protozoa and macrophages, it would be more accurate to classify them as survival factors rather than virulence factors. Given that the molecular basis of virulence variations among non-pathogenic, pathogenic, and highly pathogenic Legionella has not yet been elaborated from the perspective of virulence factors, a comprehensive explanation of how Legionella infects its natural hosts, protozoans, and accidental hosts, humans is essential to show a novel concept regarding the virulence factor of Legionella. In this review, we overviewed the pathogenic development of Legionella from protozoa, the function of conventional virulence factors in the infections of protozoa and macrophages, the host's innate immune system, and factors involved in regulating the host immune response, before discussing a probably new definition for the virulence factors of Legionella.
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8
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Vermare A, Guérin MV, Peranzoni E, Bercovici N. Dynamic CD8+ T Cell Cooperation with Macrophages and Monocytes for Successful Cancer Immunotherapy. Cancers (Basel) 2022; 14:cancers14143546. [PMID: 35884605 PMCID: PMC9318008 DOI: 10.3390/cancers14143546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Revised: 07/10/2022] [Accepted: 07/19/2022] [Indexed: 11/16/2022] Open
Abstract
Simple Summary Innate and adaptive immunity mutually regulate one another in a dynamic fashion during immune responses. In infectious contexts, positive interactions between macrophages, monocytes and T cells are well recognized, but this is not the case in the field of cancer, where the growth of tumors disturbs the immune response. However, recent advances revealed that successful immunotherapy profoundly remodels the tumor microenvironment, promoting the activation of both T cells and myeloid cells. This review highlights the studies that hint at positive CD8+ T cell cooperation with monocytes and macrophages in this context, and discusses the potential mechanisms behind this. Abstract The essential roles endorsed by macrophages and monocytes are well established in response to infections, where they contribute to launching the differentiation of specific T-lymphocytes for long-term protection. This knowledge is the result of dynamic studies that can inspire the cancer field, particularly now that cancer immunotherapies elicit some tumor regression. Indeed, immune responses to cancer have mainly been studied after tumors have escaped immune attacks. In particular, the suppressive functions of macrophages were revealed in this context, introducing an obvious bias across the literature. In this review, we will focus on the ways inwhich monocytes and macrophages cooperate with T-lymphocytes, leading to successful immune responses. We will bring together the preclinical studies that have revealed the existence of such positive cooperation in the cancer field, and we will place particular emphasis on proposing the underlying mechanisms. Finally, we will give some perspectives to decipher the functional roles of such T-cell and myeloid cell interactions in the frame of human cancer immunotherapy.
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Affiliation(s)
- Anaïs Vermare
- Université Paris Cité, Institut Cochin, INSERM, CNRS, F-75014 Paris, France;
- Equipe Labellisée Ligue Nationale Contre le Cancer, 75013 Paris, France
| | | | | | - Nadège Bercovici
- Université Paris Cité, Institut Cochin, INSERM, CNRS, F-75014 Paris, France;
- Equipe Labellisée Ligue Nationale Contre le Cancer, 75013 Paris, France
- Correspondence:
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9
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Roquilly A, Mintern JD, Villadangos JA. Spatiotemporal Adaptations of Macrophage and Dendritic Cell Development and Function. Annu Rev Immunol 2022; 40:525-557. [PMID: 35130030 DOI: 10.1146/annurev-immunol-101320-031931] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Macrophages and conventional dendritic cells (cDCs) are distributed throughout the body, maintaining tissue homeostasis and tolerance to self and orchestrating innate and adaptive immunity against infection and cancer. As they complement each other, it is important to understand how they cooperate and the mechanisms that integrate their functions. Both are exposed to commensal microbes, pathogens, and other environmental challenges that differ widely among anatomical locations and over time. To adjust to these varying conditions, macrophages and cDCs acquire spatiotemporal adaptations (STAs) at different stages of their life cycle that determine how they respond to infection. The STAs acquired in response to previous infections can result in increased responsiveness to infection, termed training, or in reduced responses, termed paralysis, which in extreme cases can cause immunosuppression. Understanding the developmental stage and location where macrophages and cDCs acquire their STAs, and the molecular and cellular players involved in their induction, may afford opportunities to harness their beneficial outcomes and avoid or reverse their deleterious effects. Here we review our current understanding of macrophage and cDC development, life cycle, function, and STA acquisition before, during, and after infection. We propose a unified framework to explain how these two cell types adjust their activities to changing conditions over space and time to coordinate their immunosurveillance functions. Expected final online publication date for the Annual Review of Immunology, Volume 40 is April 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Antoine Roquilly
- Center for Research in Transplantation and Translational Immunology, INSERM, UMR 1064, CHU Nantes, University of Nantes, Nantes, France
| | - Justine D Mintern
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, Australia
| | - Jose A Villadangos
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, Australia.,Department of Microbiology and Immunology, Doherty Institute of Infection and Immunity, The University of Melbourne, Parkville, Victoria, Australia;
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10
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Martin FP, Jacqueline C, Poschmann J, Roquilly A. Alveolar Macrophages: Adaptation to Their Anatomic Niche during and after Inflammation. Cells 2021; 10:cells10102720. [PMID: 34685700 PMCID: PMC8534884 DOI: 10.3390/cells10102720] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 10/05/2021] [Accepted: 10/06/2021] [Indexed: 12/12/2022] Open
Abstract
At the early stages of life development, alveoli are colonized by embryonic macrophages, which become resident alveolar macrophages (ResAM) and self-sustain by local division. Genetic and epigenetic signatures and, to some extent, the functions of ResAM are dictated by the lung microenvironment, which uses cytokines, ligand-receptor interactions, and stroma cells to orchestrate lung homeostasis. In resting conditions, the lung microenvironment induces in ResAM a tolerogenic programming that prevents unnecessary and potentially harmful inflammation responses to the foreign bodies, which continuously challenge the airways. Throughout life, any episode of acute inflammation, pneumonia being likely the most frequent cause, depletes the pool of ResAM, leaving space for the recruitment of inflammatory monocytes that locally develop in monocyte-derived alveolar macrophages (InfAM). During lung infection, the local microenvironment induces a temporary inflammatory signature to the recruited InfAM to handle the tissue injury and eliminate the pathogens. After a few days, the recruited InfAM, which locally self-sustain and develop as new ResAM, gain profibrotic functions required for tissue healing. After the complete resolution of the infectious episode, the functional programming of both embryonic and monocyte-derived ResAM remains altered for months and possibly for the entire life. Adult lungs thus contain a wide diversity of ResAM since every infection brings new waves of InfAM which fill the room left open by the inflammatory process. The memory of these innate cells called trained immunity constitutes an immunologic scar left by inflammation, notably pneumonia. This memory of ResAM has advantages and drawbacks. In some cases, lung-trained immunity offers better defense capacities against autoimmune disorders and the long-term risk of infection. At the opposite, it can perpetuate a harmful process and lead to a pathological state, as is the case among critically ill patients who have immune paralysis and are highly susceptible to hospital-acquired pneumonia and acute respiratory distress syndrome. The progress in understanding the kinetics of response of alveolar macrophages (AM) to lung inflammation is paving the way to new treatments of pneumonia and lung inflammatory process.
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Affiliation(s)
- Florian Pierre Martin
- EA3826 Host Pathogen Interactions, Inflammation and Mucosal Immunity, Department of Anesthesiology and Intensive Medicine, Hôtel Dieu, CHU Nantes, University of Nantes, F-44000 Nantes, France; (F.P.M.); (C.J.)
| | - Cédric Jacqueline
- EA3826 Host Pathogen Interactions, Inflammation and Mucosal Immunity, Department of Anesthesiology and Intensive Medicine, Hôtel Dieu, CHU Nantes, University of Nantes, F-44000 Nantes, France; (F.P.M.); (C.J.)
| | - Jeremie Poschmann
- Centre de Recherche en Transplantation et Immunologie, University of Nantes, UMR 1064, ITUN, Inserm, F-44000 Nantes, France;
| | - Antoine Roquilly
- EA3826 Host Pathogen Interactions, Inflammation and Mucosal Immunity, Department of Anesthesiology and Intensive Medicine, Hôtel Dieu, CHU Nantes, University of Nantes, F-44000 Nantes, France; (F.P.M.); (C.J.)
- Correspondence: ; Tel.: +33-253482230
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11
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Evidence for biosurfactant-induced flow in corners and bacterial spreading in unsaturated porous media. Proc Natl Acad Sci U S A 2021; 118:2111060118. [PMID: 34531326 DOI: 10.1073/pnas.2111060118] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/29/2021] [Indexed: 12/31/2022] Open
Abstract
The spread of pathogenic bacteria in unsaturated porous media, where air and liquid coexist in pore spaces, is the major cause of soil contamination by pathogens, soft rot in plants, food spoilage, and many pulmonary diseases. However, visualization and fundamental understanding of bacterial transport in unsaturated porous media are currently lacking, limiting the ability to address the above contamination- and disease-related issues. Here, we demonstrate a previously unreported mechanism by which bacterial cells are transported in unsaturated porous media. We discover that surfactant-producing bacteria can generate flows along corners through surfactant production that changes the wettability of the solid surface. The corner flow velocity is on the order of several millimeters per hour, which is the same order of magnitude as bacterial swarming, one of the fastest known modes of bacterial surface translocation. We successfully predict the critical corner angle for bacterial corner flow to occur based on the biosurfactant-induced change in the contact angle of the bacterial solution on the solid surface. Furthermore, we demonstrate that bacteria can indeed spread by producing biosurfactants in a model soil, which consists of packed angular grains. In addition, we demonstrate that bacterial corner flow is controlled by quorum sensing, the cell-cell communication process that regulates biosurfactant production. Understanding this previously unappreciated bacterial transport mechanism will enable more accurate predictions of bacterial spreading in soil and other unsaturated porous media.
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12
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Patel S, Tucker HR, Gogoi H, Mansouri S, Jin L. cGAS-STING and MyD88 Pathways Synergize in Ly6C hi Monocyte to Promote Streptococcus pneumoniae-Induced Late-Stage Lung IFNγ Production. Front Immunol 2021; 12:699702. [PMID: 34512626 PMCID: PMC8427188 DOI: 10.3389/fimmu.2021.699702] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Accepted: 08/05/2021] [Indexed: 01/07/2023] Open
Abstract
The cyclic GMP–AMP synthase–stimulator of interferon genes (cGAS–STING) pathway senses DNA and induces type I interferon (IFN) production. Whether and how the STING pathway crosstalk to other innate immune pathways during pathogen infection, however, remains unclear. Here, we showed that STING was needed for Streptococcus pneumoniae-induced late, not early, stage of lung IFNγ production. Using knockout mice, IFNγ reporter mice, intracellular cytokine staining, and adoptive cell transfer, we showed that cGAS–STING-dependent lung IFNγ production was independent of type I IFNs. Furthermore, STING expression in monocyte/monocyte-derived cells governed IFNγ production in the lung via the production of IL-12p70. Surprisingly, DNA stimulation alone could not induce IL-12p70 or IFNγ in Ly6Chi monocyte. The production of IFNγ required the activation by both DNA and heat-killed S. pneumococcus. Accordingly, MyD88−/− monocyte did not generate IL-12p70 or IFNγ. In summary, the cGAS–STING pathway synergizes with the MyD88 pathway in monocyte to promote late-stage lung IFNγ production during pulmonary pneumococcal infection.
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Affiliation(s)
- Seema Patel
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of Florida, Gainesville, FL, United States
| | - Heidi R Tucker
- Department of Immunology and Microbial Disease, Albany Medical College, Albany, NY, United States
| | - Himanshu Gogoi
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of Florida, Gainesville, FL, United States
| | - Samira Mansouri
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of Florida, Gainesville, FL, United States
| | - Lei Jin
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of Florida, Gainesville, FL, United States
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13
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Abstract
The Dot/Icm type IV secretion system (T4SS) of Legionella pneumophila is essential for lysosomal evasion and permissiveness of macrophages for intracellular proliferation of the pathogen. In contrast, we show that polymorphonuclear cells (PMNs) respond to a functional Dot/Icm system through rapid restriction of L. pneumophila. Specifically, we show that the L. pneumophila T4SS-injected amylase (LamA) effector catalyzes rapid glycogen degradation in the PMNs cytosol, leading to cytosolic hyperglucose. Neutrophils respond through immunometabolic reprogramming that includes upregulated aerobic glycolysis. The PMNs become activated with spatial generation of intracellular reactive oxygen species within the Legionella-containing phagosome (LCP) and fusion of specific and azurophilic granules to the LCP, leading to rapid restriction of L. pneumophila. We conclude that in contrast to macrophages, PMNs respond to a functional Dot/Icm system, and specifically to the effect of the injected amylase effector, through rapid engagement of major microbicidal processes and rapid restriction of the pathogen. IMPORTANCE Legionella pneumophila is commonly found in aquatic environments and resides within a wide variety of amoebal hosts. Upon aerosol transmission to humans, L. pneumophila invades and replicates with alveolar macrophages, causing pneumonia designated Legionnaires' disease. In addition to alveolar macrophages, neutrophils infiltrate into the lungs of infected patients. Unlike alveolar macrophages, neutrophils restrict and kill L. pneumophila, but the mechanisms were previously unclear. Here, we show that the pathogen secretes an amylase (LamA) enzyme that rapidly breakdowns glycogen stores within neutrophils, and this triggers increased glycolysis. Subsequently, the two major killing mechanisms of neutrophils, granule fusion and production of reactive oxygen species, are activated, resulting in rapid killing of L. pneumophila.
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14
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Emerging connectivity of programmed cell death pathways and its physiological implications. Nat Rev Mol Cell Biol 2020; 21:678-695. [PMID: 32873928 DOI: 10.1038/s41580-020-0270-8] [Citation(s) in RCA: 451] [Impact Index Per Article: 112.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/03/2020] [Indexed: 12/17/2022]
Abstract
The removal of functionally dispensable, infected or potentially neoplastic cells is driven by programmed cell death (PCD) pathways, highlighting their important roles in homeostasis, host defence against pathogens, cancer and a range of other pathologies. Several types of PCD pathways have been described, including apoptosis, necroptosis and pyroptosis; they employ distinct molecular and cellular processes and differ in their outcomes, such as the capacity to trigger inflammatory responses. Recent genetic and biochemical studies have revealed remarkable flexibility in the use of these PCD pathways and indicate a considerable degree of plasticity in their molecular regulation; for example, despite having a primary role in inducing pyroptosis, inflammatory caspases can also induce apoptosis, and conversely, apoptotic stimuli can trigger pyroptosis. Intriguingly, this flexibility is most pronounced in cellular responses to infection, while apoptosis is the dominant cell death process through which organisms prevent the development of cancer. In this Review, we summarize the mechanisms of the different types of PCD and describe the physiological and pathological processes that engage crosstalk between these pathways, focusing on infections and cancer. We discuss the intriguing notion that the different types of PCD could be seen as a single, coordinated cell death system, in which the individual pathways are highly interconnected and can flexibly compensate for one another.
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15
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Liu X, Boyer MA, Holmgren AM, Shin S. Legionella-Infected Macrophages Engage the Alveolar Epithelium to Metabolically Reprogram Myeloid Cells and Promote Antibacterial Inflammation. Cell Host Microbe 2020; 28:683-698.e6. [PMID: 32841604 DOI: 10.1016/j.chom.2020.07.019] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 06/18/2020] [Accepted: 07/27/2020] [Indexed: 01/05/2023]
Abstract
Alveolar macrophages are among the first immune cells that respond to inhaled pathogens. However, numerous pathogens block macrophage-intrinsic immune responses, making it unclear how robust antimicrobial responses are generated. The intracellular bacterium Legionella pneumophila inhibits host translation, thereby impairing cytokine production by infected macrophages. Nevertheless, Legionella-infected macrophages induce an interleukin-1 (IL-1)-dependent inflammatory cytokine response by recruited monocytes and other cells that controls infection. How IL-1 directs these cells to produce inflammatory cytokines is unknown. Here, we show that collaboration with the alveolar epithelium is critical for controlling infection. IL-1 induces the alveolar epithelium to produce granulocyte-macrophage colony-stimulating factor (GM-CSF). Intriguingly, GM-CSF signaling amplifies inflammatory cytokine production in recruited monocytes by enhancing Toll-like receptor (TLR)-induced glycolysis. Our findings reveal that alveolar macrophages engage alveolar epithelial signals to metabolically reprogram monocytes for antibacterial inflammation.
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Affiliation(s)
- Xin Liu
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Mark A Boyer
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Alicia M Holmgren
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Sunny Shin
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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16
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Wang H, Kjer-Nielsen L, Shi M, D'Souza C, Pediongco TJ, Cao H, Kostenko L, Lim XY, Eckle SBG, Meehan BS, Zhu T, Wang B, Zhao Z, Mak JYW, Fairlie DP, Teng MWL, Rossjohn J, Yu D, de St Groth BF, Lovrecz G, Lu L, McCluskey J, Strugnell RA, Corbett AJ, Chen Z. IL-23 costimulates antigen-specific MAIT cell activation and enables vaccination against bacterial infection. Sci Immunol 2020; 4:4/41/eaaw0402. [PMID: 31732518 DOI: 10.1126/sciimmunol.aaw0402] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 05/09/2019] [Accepted: 10/18/2019] [Indexed: 12/11/2022]
Abstract
Mucosal-associated invariant T (MAIT) cells are activated in a TCR-dependent manner by antigens derived from the riboflavin synthesis pathway, including 5-(2-oxopropylideneamino)-6-d-ribitylaminouracil (5-OP-RU), bound to MHC-related protein-1 (MR1). However, MAIT cell activation in vivo has not been studied in detail. Here, we have found and characterized additional molecular signals required for optimal activation and expansion of MAIT cells after pulmonary Legionella or Salmonella infection in mice. We show that either bone marrow-derived APCs or non-bone marrow-derived cells can activate MAIT cells in vivo, depending on the pathogen. Optimal MAIT cell activation in vivo requires signaling through the inducible T cell costimulator (ICOS), which is highly expressed on MAIT cells. Subsequent expansion and maintenance of MAIT-17/1-type responses are dependent on IL-23. Vaccination with IL-23 plus 5-OP-RU augments MAIT cell-mediated control of pulmonary Legionella infection. These findings reveal cellular and molecular targets for manipulating MAIT cell function under physiological conditions.
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Affiliation(s)
- Huimeng Wang
- Department of Microbiology and Immunology, University of Melbourne, Peter Doherty Institute for Infection and Immunity, Melbourne, VIC 3000, Australia.,State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong 510182, China
| | - Lars Kjer-Nielsen
- Department of Microbiology and Immunology, University of Melbourne, Peter Doherty Institute for Infection and Immunity, Melbourne, VIC 3000, Australia
| | - Mai Shi
- Department of Microbiology and Immunology, University of Melbourne, Peter Doherty Institute for Infection and Immunity, Melbourne, VIC 3000, Australia.,School of Medicine, Tsinghua University, Beijing, China
| | - Criselle D'Souza
- Department of Microbiology and Immunology, University of Melbourne, Peter Doherty Institute for Infection and Immunity, Melbourne, VIC 3000, Australia.,Sir Peter MacCallum Department of Oncology, University of Melbourne, VIC 3010, Australia
| | - Troi J Pediongco
- Department of Microbiology and Immunology, University of Melbourne, Peter Doherty Institute for Infection and Immunity, Melbourne, VIC 3000, Australia
| | - Hanwei Cao
- Department of Microbiology and Immunology, University of Melbourne, Peter Doherty Institute for Infection and Immunity, Melbourne, VIC 3000, Australia
| | - Lyudmila Kostenko
- Department of Microbiology and Immunology, University of Melbourne, Peter Doherty Institute for Infection and Immunity, Melbourne, VIC 3000, Australia
| | - Xin Yi Lim
- Department of Microbiology and Immunology, University of Melbourne, Peter Doherty Institute for Infection and Immunity, Melbourne, VIC 3000, Australia
| | - Sidonia B G Eckle
- Department of Microbiology and Immunology, University of Melbourne, Peter Doherty Institute for Infection and Immunity, Melbourne, VIC 3000, Australia
| | - Bronwyn S Meehan
- Department of Microbiology and Immunology, University of Melbourne, Peter Doherty Institute for Infection and Immunity, Melbourne, VIC 3000, Australia
| | - Tianyuan Zhu
- Department of Microbiology and Immunology, University of Melbourne, Peter Doherty Institute for Infection and Immunity, Melbourne, VIC 3000, Australia.,School of Medicine, Tsinghua University, Beijing, China
| | - Bingjie Wang
- Department of Microbiology and Immunology, University of Melbourne, Peter Doherty Institute for Infection and Immunity, Melbourne, VIC 3000, Australia
| | - Zhe Zhao
- Department of Microbiology and Immunology, University of Melbourne, Peter Doherty Institute for Infection and Immunity, Melbourne, VIC 3000, Australia
| | - Jeffrey Y W Mak
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, University of Queensland, Saint Lucia, QLD 4072, Australia.,Australian Research Council Centre of Excellence in Advanced Molecular Imaging, University of Queensland, Saint Lucia, QLD 4072, Australia
| | - David P Fairlie
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, University of Queensland, Saint Lucia, QLD 4072, Australia.,Australian Research Council Centre of Excellence in Advanced Molecular Imaging, University of Queensland, Saint Lucia, QLD 4072, Australia
| | - Michele W L Teng
- QIMR Berghofer Medical Research Institute, Herston, QLD 4006, Australia
| | - Jamie Rossjohn
- Infection and Immunity Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia.,Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, VIC 3800, Australia.,Institute of Infection and Immunity, Cardiff University, School of Medicine, Heath Park, CF14 4XN Wales, UK
| | - Di Yu
- John Curtin School of Medical Research, The Australian National University, Acton, ACT 2601 Australia
| | - Barbara Fazekas de St Groth
- Discipline of Pathology, Charles Perkins Centre, Faculty of Medicine and Health, University of Sydney, Sydney, NSW 2006, Australia
| | - George Lovrecz
- Biomedical Manufacturing, CSIRO, Parkville, VIC, 3052, Australia
| | - Louis Lu
- Biomedical Manufacturing, CSIRO, Parkville, VIC, 3052, Australia
| | - James McCluskey
- Department of Microbiology and Immunology, University of Melbourne, Peter Doherty Institute for Infection and Immunity, Melbourne, VIC 3000, Australia
| | - Richard A Strugnell
- Department of Microbiology and Immunology, University of Melbourne, Peter Doherty Institute for Infection and Immunity, Melbourne, VIC 3000, Australia.
| | - Alexandra J Corbett
- Department of Microbiology and Immunology, University of Melbourne, Peter Doherty Institute for Infection and Immunity, Melbourne, VIC 3000, Australia.
| | - Zhenjun Chen
- Department of Microbiology and Immunology, University of Melbourne, Peter Doherty Institute for Infection and Immunity, Melbourne, VIC 3000, Australia.
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17
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Yang C, McDermot DS, Pasricha S, Brown AS, Bedoui S, Lenz LL, van Driel IR, Hartland EL. IFNγ receptor down-regulation facilitates Legionella survival in alveolar macrophages. J Leukoc Biol 2020; 107:273-284. [PMID: 31793076 PMCID: PMC8015206 DOI: 10.1002/jlb.4ma1019-152r] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2019] [Revised: 10/10/2019] [Accepted: 10/30/2019] [Indexed: 12/17/2022] Open
Abstract
Legionella pneumophila is an opportunistic human pathogen and causative agent of the acute pneumonia known as Legionnaire's disease. Upon inhalation, the bacteria replicate in alveolar macrophages (AM), within an intracellular vacuole termed the Legionella-containing vacuole. We recently found that, in vivo, IFNγ was required for optimal clearance of intracellular L. pneumophila by monocyte-derived cells (MC), but the cytokine did not appear to influence clearance by AM. Here, we report that during L. pneumophila lung infection, expression of the IFNγ receptor subunit 1 (IFNGR1) is down-regulated in AM and neutrophils, but not MC, offering a possible explanation for why AM are unable to effectively restrict L. pneumophila replication in vivo. To test this, we used mice that constitutively express IFNGR1 in AM and found that prevention of IFNGR1 down-regulation enhanced the ability of AM to restrict L. pneumophila intracellular replication. IFNGR1 down-regulation was independent of the type IV Dot/Icm secretion system of L. pneumophila indicating that bacterial effector proteins were not involved. In contrast to previous work, we found that signaling via type I IFN receptors was not required for IFNGR1 down-regulation in macrophages but rather that MyD88- or Trif- mediated NF-κB activation was required. This work has uncovered an alternative signaling pathway responsible for IFNGR1 down-regulation in macrophages during bacterial infection.
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Affiliation(s)
- Chao Yang
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Daniel S McDermot
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Denver, Colorado, USA
| | - Shivani Pasricha
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, Australia
| | - Andrew S Brown
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, Victoria, Australia
| | - Sammy Bedoui
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Laurel L Lenz
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Denver, Colorado, USA
| | - Ian R van Driel
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, Victoria, Australia
| | - Elizabeth L Hartland
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, Australia
- Department of Molecular and Translational Science, Monash University, Melbourne, Victoria, Australia
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18
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IRG1 and Inducible Nitric Oxide Synthase Act Redundantly with Other Interferon-Gamma-Induced Factors To Restrict Intracellular Replication of Legionella pneumophila. mBio 2019; 10:mBio.02629-19. [PMID: 31719183 PMCID: PMC6851286 DOI: 10.1128/mbio.02629-19] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Legionella pneumophila is one example among many species of pathogenic bacteria that replicate within mammalian macrophages during infection. The immune signaling factor interferon gamma (IFN-γ) blocks L. pneumophila replication in macrophages and is an essential component of the immune response to L. pneumophila and other intracellular pathogens. However, to date, no study has identified the exact molecular factors induced by IFN-γ that are required for its activity. We generated macrophages lacking different combinations of IFN-γ-induced genes in an attempt to find a genetic background in which there is a complete loss of IFN-γ-mediated restriction of L. pneumophila. We identified six genes that comprise the totality of the IFN-γ-dependent restriction of L. pneumophila replication in macrophages. Our results clarify the molecular basis underlying the potent effects of IFN-γ and highlight how redundancy downstream of IFN-γ is key to prevent exploitation of macrophages by pathogens. Interferon gamma (IFN-γ) restricts the intracellular replication of many pathogens, but the mechanism by which IFN-γ confers cell-intrinsic pathogen resistance remains unclear. For example, intracellular replication of the bacterial pathogen Legionella pneumophila in macrophages is potently curtailed by IFN-γ. However, consistent with prior studies, no individual genetic deficiency that we tested completely abolished IFN-γ-mediated control. Intriguingly, we observed that the glycolysis inhibitor 2-deoxyglucose (2DG) partially rescued L. pneumophila replication in IFN-γ-treated macrophages. 2DG inhibits glycolysis and triggers the unfolded protein response, but unexpectedly, it appears these effects are not responsible for perturbing the antimicrobial activity of IFN-γ. Instead, we found that 2DG rescues bacterial replication by inhibiting the expression of two key antimicrobial factors, inducible nitric oxide synthase (iNOS) and immune-responsive gene 1 (IRG1). Using immortalized and primary macrophages deficient in iNOS and IRG1, we confirmed that loss of both iNOS and IRG1, but not individual deficiency in either gene, partially reduced IFN-γ-mediated restriction of L. pneumophila. Further, using a combinatorial CRISPR/Cas9 mutagenesis approach, we found that mutation of iNOS and IRG1 in combination with four other genes (CASP11, IRGM1, IRGM3, and NOX2) resulted in a total loss of L. pneumophila restriction by IFN-γ in primary bone marrow macrophages. Our study defines a complete set of cell-intrinsic factors required for IFN-γ-mediated restriction of an intracellular bacterial pathogen and highlights the combinatorial strategy used by hosts to block bacterial replication in macrophages.
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19
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Anderson BM, Poole DP, Aurelio L, Ng GZ, Fleischmann M, Kasperkiewicz P, Morissette C, Drag M, van Driel IR, Schmidt BL, Vanner SJ, Bunnett NW, Edgington-Mitchell LE. Application of a chemical probe to detect neutrophil elastase activation during inflammatory bowel disease. Sci Rep 2019; 9:13295. [PMID: 31527638 PMCID: PMC6746801 DOI: 10.1038/s41598-019-49840-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 08/31/2019] [Indexed: 12/14/2022] Open
Abstract
Neutrophil elastase is a serine protease that has been implicated in the pathogenesis of inflammatory bowel disease. Due to post-translational control of its activation and high expression of its inhibitors in the gut, measurements of total expression poorly reflect the pool of active, functional neutrophil elastase. Fluorogenic substrate probes have been used to measure neutrophil elastase activity, though these tools lack specificity and traceability. PK105 is a recently described fluorescent activity-based probe, which binds to neutrophil elastase in an activity-dependent manner. The irreversible nature of this probe allows for accurate identification of its targets in complex protein mixtures. We describe the reactivity profile of PK105b, a new analogue of PK105, against recombinant serine proteases and in tissue extracts from healthy mice and from models of inflammation induced by oral cancer and Legionella pneumophila infection. We apply PK105b to measure neutrophil elastase activation in an acute model of experimental colitis. Neutrophil elastase activity is detected in inflamed, but not healthy, colons. We corroborate this finding in mucosal biopsies from patients with ulcerative colitis. Thus, PK105b facilitates detection of neutrophil elastase activity in tissue lysates, and we have applied it to demonstrate that this protease is unequivocally activated during colitis.
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Affiliation(s)
- Bethany M Anderson
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC, Australia.,Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Daniel P Poole
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Luigi Aurelio
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Garrett Z Ng
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC, Australia
| | - Markus Fleischmann
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC, Australia.,Department of Cellular Immunology, Institute of Experimental Immunology, University Hospital Bonn, Bonn, Germany
| | - Paulina Kasperkiewicz
- Department of Bioorganic Chemistry, Wroclaw University of Technology, Wroclaw, Poland
| | - Celine Morissette
- Gastrointestinal Diseases Research Unit, Kingston General Hospital, Queen's University, Kingston, ON, Canada
| | - Marcin Drag
- Department of Bioorganic Chemistry, Wroclaw University of Technology, Wroclaw, Poland
| | - Ian R van Driel
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC, Australia
| | - Brian L Schmidt
- Department of Oral and Maxillofacial Surgery, New York University College of Dentistry, Bluestone Center for Clinical Research, New York, New York, USA
| | - Stephen J Vanner
- Gastrointestinal Diseases Research Unit, Kingston General Hospital, Queen's University, Kingston, ON, Canada
| | - Nigel W Bunnett
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia.,Departments of Surgery and Pharmacology, Columbia University, New York, New York, USA.,Department of Pharmacology and Experimental Therapeutics, The University of Melbourne, Parkville, VIC, Australia
| | - Laura E Edgington-Mitchell
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC, Australia. .,Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia. .,Department of Oral and Maxillofacial Surgery, New York University College of Dentistry, Bluestone Center for Clinical Research, New York, New York, USA.
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20
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Viewing Legionella pneumophila Pathogenesis through an Immunological Lens. J Mol Biol 2019; 431:4321-4344. [PMID: 31351897 DOI: 10.1016/j.jmb.2019.07.028] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 06/25/2019] [Accepted: 07/13/2019] [Indexed: 12/14/2022]
Abstract
Legionella pneumophila is the causative agent of the severe pneumonia Legionnaires' disease. L. pneumophila is ubiquitously found in freshwater environments, where it replicates within free-living protozoa. Aerosolization of contaminated water supplies allows the bacteria to be inhaled into the human lung, where L. pneumophila can be phagocytosed by alveolar macrophages and replicate intracellularly. The Dot/Icm type IV secretion system (T4SS) is one of the key virulence factors required for intracellular bacterial replication and subsequent disease. The Dot/Icm apparatus translocates more than 300 effector proteins into the host cell cytosol. These effectors interfere with a variety of cellular processes, thus enabling the bacterium to evade phagosome-lysosome fusion and establish an endoplasmic reticulum-derived Legionella-containing vacuole, which facilitates bacterial replication. In turn, the immune system has evolved numerous strategies to recognize intracellular bacteria such as L. pneumophila, leading to potent inflammatory responses that aid in eliminating infection. This review aims to provide an overview of L. pneumophila pathogenesis in the context of the host immune response.
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21
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Rahman T, Brown AS, Hartland EL, van Driel IR, Fung KY. Plasmacytoid Dendritic Cells Provide Protection Against Bacterial-Induced Colitis. Front Immunol 2019; 10:608. [PMID: 31024525 PMCID: PMC6465541 DOI: 10.3389/fimmu.2019.00608] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 03/07/2019] [Indexed: 12/19/2022] Open
Abstract
We have examined the influence of depleting plasmacytoid dendritic cells (pDC) in mice on the immune response to the gut pathogen Citrobacter rodentium, an organism that is a model for human attaching effacing pathogens such as enterohaemorraghic E. coli. A significantly higher number of C. rodentium were found in mice depleted of pDC from 7 days after infection and pDC depleted mice showed increased gut pathology and higher levels of mRNA encoding inflammatory cytokines in the colon upon infection. pDC-depletion led to a compromising of the gut mucosal barrier that may have contributed to increased numbers of C. rodentium in systemic organs. pDC-depleted mice infected with C. rodentium suffered substantial weight loss necessitating euthanasia. A number of observations suggested that this was not simply the result of dysregulation of immunity in the colon as pDC-depleted mice infected intravenously with C. rodentium also exhibited exacerbated weight loss, arguing that pDC influence systemic immune responses. Overall, these data indicate that pDC contribute at multiple levels to immunity to C. rodentium including control of bacterial numbers in the colon, maintenance of colon barrier function and regulation of immune responses to disseminated bacteria.
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Affiliation(s)
- Tania Rahman
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia.,Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, VIC, Australia
| | - Andrew S Brown
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, VIC, Australia
| | - Elizabeth L Hartland
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia
| | - Ian R van Driel
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, VIC, Australia
| | - Ka Yee Fung
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia
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22
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Abstract
Infection of C57BL/6 mice with wild-type Legionella pneumophila typically results in very mild disease. However, in mice where the cytosolic recognition of flagellin is impaired by mutation, L. pneumophila infection results in more severe lung inflammation that is reminiscent of Legionnaires' disease. This can be replicated in wild-type mice by using aflagellated mutants of L. pneumophila. These models greatly facilitate the investigation of L. pneumophila virulence factors and the complex pulmonary immune system that is triggered by infection. Here we describe methods for infecting C57BL/6 mice with aflagellated L. pneumophila, the quantification of bacterial load in the lungs and isolation and analysis of invading immune cells. These assays enable the identification of phagocyte subsets and can determine whether phagocytic cells act as a replicative niche for L. pneumophila replication.
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23
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MAIT cells protect against pulmonary Legionella longbeachae infection. Nat Commun 2018; 9:3350. [PMID: 30135490 PMCID: PMC6105587 DOI: 10.1038/s41467-018-05202-8] [Citation(s) in RCA: 141] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 04/27/2018] [Indexed: 02/07/2023] Open
Abstract
Mucosal associated invariant T (MAIT) cells recognise conserved microbial metabolites from riboflavin synthesis. Striking evolutionary conservation and pulmonary abundance implicate them in antibacterial host defence, yet their functions in protection against clinically important pathogens are unknown. Here we show that mouse Legionella longbeachae infection induces MR1-dependent MAIT cell activation and rapid pulmonary accumulation of MAIT cells associated with immune protection detectable in immunocompetent host animals. MAIT cell protection is more evident in mice lacking CD4+ cells, and adoptive transfer of MAIT cells rescues immunodeficient Rag2-/-γC-/- mice from lethal Legionella infection. Protection is dependent on MR1, IFN-γ and GM-CSF, but not IL-17A, TNF or perforin, and enhanced protection is detected earlier after infection of mice antigen-primed to boost MAIT cell numbers before infection. Our findings define a function for MAIT cells in protection against a major human pathogen and indicate a potential role for vaccination to enhance MAIT cell immunity.
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24
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Ruiz-Moreno JS, Hamann L, Shah JA, Verbon A, Mockenhaupt FP, Puzianowska-Kuznicka M, Naujoks J, Sander LE, Witzenrath M, Cambier JC, Suttorp N, Schumann RR, Jin L, Hawn TR, Opitz B. The common HAQ STING variant impairs cGAS-dependent antibacterial responses and is associated with susceptibility to Legionnaires' disease in humans. PLoS Pathog 2018; 14:e1006829. [PMID: 29298342 PMCID: PMC5770077 DOI: 10.1371/journal.ppat.1006829] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 01/16/2018] [Accepted: 12/18/2017] [Indexed: 11/23/2022] Open
Abstract
The cyclic GMP-AMP synthase (cGAS)-STING pathway is central for innate immune sensing of various bacterial, viral and protozoal infections. Recent studies identified the common HAQ and R232H alleles of TMEM173/STING, but the functional consequences of these variants for primary infections are unknown. Here we demonstrate that cGAS- and STING-deficient murine macrophages as well as human cells of individuals carrying HAQ TMEM173/STING were severely impaired in producing type I IFNs and pro-inflammatory cytokines in response to Legionella pneumophila, bacterial DNA or cyclic dinucleotides (CDNs). In contrast, R232H attenuated cytokine production only following stimulation with bacterial CDN, but not in response to L. pneumophila or DNA. In a mouse model of Legionnaires’ disease, cGAS- and STING-deficient animals exhibited higher bacterial loads as compared to wild-type mice. Moreover, the haplotype frequency of HAQ TMEM173/STING, but not of R232H TMEM173/STING, was increased in two independent cohorts of human Legionnaires’ disease patients as compared to healthy controls. Our study reveals that the cGAS-STING cascade contributes to antibacterial defense against L. pneumophila in mice and men, and provides important insight into how the common HAQ TMEM173/STING variant affects antimicrobial immune responses and susceptibility to infection. Interferons (IFNs) and pro-inflammatory cytokines are key regulators of gene expression and antibacterial defense during Legionella pneumophila infection. Here we demonstrate that production of these mediators was largely or partly dependent on the cyclic GMP-AMP synthase (cGAS)-STING pathway in human and murine cells. Cells of individuals carrying the common HAQ allele of TMEM173/STING were strongly impaired in their ability to respond to L. pneumophila, bacterial DNA or cyclic dinucleotides (CDNs), whereas the R232H allele was only attenuated in sensing of exogenous CDNs. Importantly, cGAS and STING contributed to antibacterial defense in mice during L. pneumophila lung infection, and the allele frequency of HAQ TMEM173/STING, but not of R232H TMEM173/STING, was increased in two independent cohorts of human Legionnaires’ disease patients as compared to healthy controls. Hence, sensing of bacterial DNA by the cGAS/STING pathway contributes to antibacterial defense against L. pneumophila infection, and the hypomorphic variant HAQ TMEM173/STING is associated with increased susceptibility to Legionnaires’ disease in humans.
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Affiliation(s)
- Juan S. Ruiz-Moreno
- Department of Internal Medicine/Infectious Diseases and Pulmonary Medicine, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Lutz Hamann
- Institute of Microbiology and Hygiene, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health Berlin, Berlin, Germany
| | - Javeed A. Shah
- Department of Medicine, University of Washington, Seattle, Washington, United states of America
- VA Puget Sound Health Care System, Seattle, Washington, United states of America
| | - Annelies Verbon
- Department of Medical Microbiology and Infectious diseases, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Frank P. Mockenhaupt
- Institute of Tropical Medicine and International Health, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Monika Puzianowska-Kuznicka
- Department of Human Epigenetics, Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland
- Department of Geriatrics and Gerontology, Medical Centre of Postgraduate Education, Warsaw, Poland
| | - Jan Naujoks
- Department of Internal Medicine/Infectious Diseases and Pulmonary Medicine, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Leif E. Sander
- Department of Internal Medicine/Infectious Diseases and Pulmonary Medicine, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
- German Center for Lung Research (DZL), Germany
| | - Martin Witzenrath
- Department of Internal Medicine/Infectious Diseases and Pulmonary Medicine, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
- German Center for Lung Research (DZL), Germany
- CAPNETZ STIFTUNG, Hannover, Germany
| | - John C. Cambier
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, Colorado, United States of America
| | - Norbert Suttorp
- Department of Internal Medicine/Infectious Diseases and Pulmonary Medicine, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
- German Center for Lung Research (DZL), Germany
- CAPNETZ STIFTUNG, Hannover, Germany
| | - Ralf R. Schumann
- Institute of Microbiology and Hygiene, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health Berlin, Berlin, Germany
| | - Lei Jin
- Department of Medicine, Division of Pulmonary, Critical Care and Sleep Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Thomas R. Hawn
- Department of Medicine, University of Washington, Seattle, Washington, United states of America
| | - Bastian Opitz
- Department of Internal Medicine/Infectious Diseases and Pulmonary Medicine, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
- German Center for Lung Research (DZL), Germany
- * E-mail:
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25
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Multiple Legionella pneumophila effector virulence phenotypes revealed through high-throughput analysis of targeted mutant libraries. Proc Natl Acad Sci U S A 2017; 114:E10446-E10454. [PMID: 29133401 DOI: 10.1073/pnas.1708553114] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Legionella pneumophila is the causative agent of a severe pneumonia called Legionnaires' disease. A single strain of L. pneumophila encodes a repertoire of over 300 different effector proteins that are delivered into host cells by the Dot/Icm type IV secretion system during infection. The large number of L. pneumophila effectors has been a limiting factor in assessing the importance of individual effectors for virulence. Here, a transposon insertion sequencing technology called INSeq was used to analyze replication of a pool of effector mutants in parallel both in a mouse model of infection and in cultured host cells. Loss-of-function mutations in genes encoding effector proteins resulted in host-specific or broad virulence phenotypes. Screen results were validated for several effector mutants displaying different virulence phenotypes using genetic complementation studies and infection assays. Specifically, loss-of-function mutations in the gene encoding LegC4 resulted in enhanced L. pneumophila in the lungs of infected mice but not within cultured host cells, which indicates LegC4 augments bacterial clearance by the host immune system. The effector proteins RavY and Lpg2505 were important for efficient replication within both mammalian and protozoan hosts. Further analysis of Lpg2505 revealed that this protein functions as a metaeffector that counteracts host cytotoxicity displayed by the effector protein SidI. Thus, this study identified a large cohort of effectors that contribute to L. pneumophila virulence positively or negatively and has demonstrated regulation of effector protein activities by cognate metaeffectors as being critical for host pathogenesis.
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26
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Naujoks J, Lippmann J, Suttorp N, Opitz B. Innate sensing and cell-autonomous resistance pathways in Legionella pneumophila infection. Int J Med Microbiol 2017; 308:161-167. [PMID: 29097162 DOI: 10.1016/j.ijmm.2017.10.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2017] [Revised: 10/20/2017] [Accepted: 10/23/2017] [Indexed: 12/20/2022] Open
Abstract
Legionella pneumophila is a facultative intracellular bacterium which can cause a severe pneumonia called Legionnaires' disease after inhalation of contaminated water droplets and replication in alveolar macrophages. The innate immune system is generally able to sense and -in most cases- control L. pneumophila infection. Comorbidities and genetic risk factors, however, can compromise the immune system and high infection doses might overwhelm its capacity, thereby enabling L. pneumophila to grow and disseminate inside the lung. The innate immune system mediates sensing of L. pneumophila by employing e.g. NOD-like receptors (NLRs), Toll-like receptors (TLRs), as well as the cGAS/STING pathway to stimulate death of infected macrophages as well as production of proinflammatory cytokines and interferons (IFNs). Control of pulmonary L. pneumophila infection is largely mediated by inflammasome-, TNFα- and IFN-dependent macrophage-intrinsic resistance mechanisms. This article summarizes the current knowledge of innate immune responses to L. pneumophila infection in general, and of macrophage-intrinsic defense mechanisms in particular.
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Affiliation(s)
- Jan Naujoks
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Internal Medicine/Infectious Diseases and Pulmonary Medicine, Augustenburger Platz 1, 13353 Berlin, Germany
| | - Juliane Lippmann
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Internal Medicine/Infectious Diseases and Pulmonary Medicine, Augustenburger Platz 1, 13353 Berlin, Germany
| | - Norbert Suttorp
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Internal Medicine/Infectious Diseases and Pulmonary Medicine, Augustenburger Platz 1, 13353 Berlin, Germany
| | - Bastian Opitz
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Internal Medicine/Infectious Diseases and Pulmonary Medicine, Augustenburger Platz 1, 13353 Berlin, Germany; German Center for Lung Research (DZL), Germany.
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27
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Casson CN, Doerner JL, Copenhaver AM, Ramirez J, Holmgren AM, Boyer MA, Siddarthan IJ, Rouhanifard SH, Raj A, Shin S. Neutrophils and Ly6Chi monocytes collaborate in generating an optimal cytokine response that protects against pulmonary Legionella pneumophila infection. PLoS Pathog 2017; 13:e1006309. [PMID: 28384349 PMCID: PMC5404877 DOI: 10.1371/journal.ppat.1006309] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2016] [Revised: 04/25/2017] [Accepted: 03/22/2017] [Indexed: 12/14/2022] Open
Abstract
Early responses mounted by both tissue-resident and recruited innate immune cells are essential for host defense against bacterial pathogens. In particular, both neutrophils and Ly6Chi monocytes are rapidly recruited to sites of infection. While neutrophils and monocytes produce bactericidal molecules, such as reactive nitrogen and oxygen species, both cell types are also capable of synthesizing overlapping sets of cytokines important for host defense. Whether neutrophils and monocytes perform redundant or non-redundant functions in the generation of anti-microbial cytokine responses remains elusive. Here, we sought to define the contributions of neutrophils and Ly6Chi monocytes to cytokine production and host defense during pulmonary infection with Legionella pneumophila, responsible for the severe pneumonia Legionnaires' disease. We found that both neutrophils and monocytes are critical for host defense against L. pneumophila. Both monocytes and neutrophils contribute to maximal IL-12 and IFNγ responses, and monocytes are also required for TNF production. Moreover, natural killer (NK) cells, NKT cells, and γδ T cells are sources of IFNγ, and monocytes direct IFNγ production by these cell types. Thus, neutrophils and monocytes cooperate in eliciting an optimal cytokine response that promotes effective control of bacterial infection.
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Affiliation(s)
- Cierra N. Casson
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Jessica L. Doerner
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Alan M. Copenhaver
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Jasmine Ramirez
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Alicia M. Holmgren
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Mark A. Boyer
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Ingharan J. Siddarthan
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Sara H. Rouhanifard
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Arjun Raj
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Sunny Shin
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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28
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Wright MD, Binger KJ. Macrophage heterogeneity and renin-angiotensin system disorders. Pflugers Arch 2017; 469:445-454. [PMID: 28176018 DOI: 10.1007/s00424-017-1940-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 01/17/2017] [Accepted: 01/19/2017] [Indexed: 12/21/2022]
Abstract
Macrophages are heterogeneous innate immune cells which are important in both the maintenance of tissue homeostasis and its disruption, by promoting tissue inflammation and fibrosis. The renin-angiotensin system is central to the pathophysiology of a large suite of diseases, which are driven in part by large amounts of tissue inflammation and fibrosis. Here, we review recent advances in understanding macrophage heterogeneity in origin and function, and how these may lead to new insights into the pathogenesis of these chronic diseases.
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Affiliation(s)
- Mark D Wright
- Department of Immunology, Monash University, Prahran, Victoria, Australia
| | - Katrina J Binger
- Department of Biochemistry and Molecular Biology, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Parkville, Victoria, Australia.
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29
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Park B, Park G, Kim J, Lim SA, Lee KM. Innate immunity against Legionella pneumophila during pulmonary infections in mice. Arch Pharm Res 2017; 40:131-145. [PMID: 28063015 DOI: 10.1007/s12272-016-0859-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 11/02/2016] [Indexed: 01/01/2023]
Abstract
Legionella pneumophila is an etiological agent of the severe pneumonia known as Legionnaires' disease (LD). This gram-negative bacterium is thought to replicate naturally in various freshwater amoebae, but also replicates in human alveolar macrophages. Inside host cells, legionella induce the production of non-endosomal replicative phagosomes by injecting effector proteins into the cytosol. Innate immune responses are first line defenses against legionella during early phases of infection, and distinguish between legionella and host cells using germline-encoded pattern recognition receptors such as Toll-like receptors , NOD-like receptors, and RIG-I-like receptors, which sense pathogen-associated molecular patterns that are absent in host cells. During pulmonary legionella infections, various inflammatory cells such as macrophages, neutrophils, natural killer (NK) cells, large mononuclear cells, B cells, and CD4+ and CD8+ T cells are recruited into infected lungs, and predominantly occupy interstitial areas to control legionella. During pulmonary legionella infections, the interplay between distinct cytokines and chemokines also modulates innate host responses to clear legionella from the lungs. Recognition by NK cell receptors triggers effector functions including secretion of cytokines and chemokines, and leads to lysis of target cells. Crosstalk between NK cells and dendritic cells, monocytes, and macrophages provides a major first-line defense against legionella infection, whereas activation of T and B cells resolves the infection and mounts legionella-specific memory in the host.
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Affiliation(s)
- Bonggoo Park
- Global Research Laboratory, Department of Biochemistry and Molecular Biology, Korea University College of Medicine, 126-1 Anam-dong 5-ga, Seongbuk-gu, Seoul, 136-713, Korea
| | - Gayoung Park
- Global Research Laboratory, Department of Biochemistry and Molecular Biology, Korea University College of Medicine, 126-1 Anam-dong 5-ga, Seongbuk-gu, Seoul, 136-713, Korea.,Department of Biomicrosystem Technology, Korea University, Seoul, 136-701, Korea
| | - Jiyoung Kim
- Global Research Laboratory, Department of Biochemistry and Molecular Biology, Korea University College of Medicine, 126-1 Anam-dong 5-ga, Seongbuk-gu, Seoul, 136-713, Korea
| | - Seon Ah Lim
- Global Research Laboratory, Department of Biochemistry and Molecular Biology, Korea University College of Medicine, 126-1 Anam-dong 5-ga, Seongbuk-gu, Seoul, 136-713, Korea
| | - Kyung-Mi Lee
- Global Research Laboratory, Department of Biochemistry and Molecular Biology, Korea University College of Medicine, 126-1 Anam-dong 5-ga, Seongbuk-gu, Seoul, 136-713, Korea.
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