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Hartland EL, Shin S. Editorial overview: Getting the house in order: Cell-intrinsic mechanisms of innate immune defence. Curr Opin Immunol 2024; 86:102411. [PMID: 38428280 DOI: 10.1016/j.coi.2024.102411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/03/2024]
Affiliation(s)
- Elizabeth L Hartland
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton 3168, Victoria, Australia; Department of Molecular and Translational Science, Monash University, Clayton 3168, Victoria, Australia.
| | - Sunny Shin
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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2
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Hartland EL, Ghosal D, Giogha C. Manipulation of epithelial cell architecture by the bacterial pathogens Listeria and Shigella. Curr Opin Cell Biol 2022; 79:102131. [PMID: 36215855 DOI: 10.1016/j.ceb.2022.102131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 08/22/2022] [Accepted: 09/06/2022] [Indexed: 01/31/2023]
Abstract
Subversion of the host cell cytoskeleton is a virulence attribute common to many bacterial pathogens. On mucosal surfaces, bacteria have evolved distinct ways of interacting with the polarised epithelium and manipulating host cell structure to propagate infection. For example, Shigella and Listeria induce cytoskeletal changes to induce their own uptake into enterocytes in order to replicate within an intracellular environment and then spread from cell-to-cell by harnessing the host actin cytoskeleton. In this review, we highlight some recent studies that advance our understanding of the role of the host cell cytoskeleton in the mechanical and molecular processes of pathogen invasion, cell-to-cell spread and the impact of infection on epithelial intercellular tension and innate mucosal defence.
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Affiliation(s)
- Elizabeth L Hartland
- 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.
| | - Debnath Ghosal
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, VIC, Australia
| | - Cristina Giogha
- 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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Hartland EL. Emerging technologies in microbiology. Mol Microbiol 2022; 117:551-552. [PMID: 35303397 DOI: 10.1111/mmi.14888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Elizabeth L Hartland
- 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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Wibawa RR, Li P, McCaffrey K, Hartland EL. Using Genomic Deletion Mutants to Investigate Effector-Triggered Immunity During Legionella pneumophila Infection. Methods Mol Biol 2022; 2523:23-41. [PMID: 35759189 DOI: 10.1007/978-1-0716-2449-4_3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Legionella pneumophila is an intracellular bacterial pathogen that uses a type IV secretion system (T4SS), termed Dot/Icm, to secrete more than 330 virulence effector proteins into the infected host cell. Many Dot/Icm effectors are involved in biogenesis of the Legionella-containing vacuole (LCV), which allows intracellular bacterial replication in environmental amoebae and alveolar macrophages. Through their activity, some effectors trigger the mammalian host immune response in a phenomenon termed effector-triggered immunity (ETI). Here, we describe a protocol to create and use L. pneumophila genome deletion mutants to identify effector(s) that alter pro-inflammatory cytokine production and bacterial clearance in the lungs of mice.
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Affiliation(s)
- Rachelia R Wibawa
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, VIC, Australia
- Department of Molecular and Translational Science, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, VIC, Australia
| | - Pengfei Li
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, VIC, Australia
- Department of Molecular and Translational Science, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, VIC, Australia
- National Clinical Research Center for Hematologic Diseases, Soochow University, Suzhou, China
| | - Kathleen McCaffrey
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, VIC, Australia
- Department of Molecular and Translational Science, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, VIC, Australia
| | - Elizabeth L Hartland
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, VIC, Australia.
- Department of Molecular and Translational Science, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, VIC, Australia.
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Tran TT, Mathmann CD, Gatica-Andrades M, Rollo RF, Oelker M, Ljungberg JK, Nguyen TTK, Zamoshnikova A, Kummari LK, Wyer OJK, Irvine KM, Melo-Bolívar J, Gross A, Brown D, Mak JYW, Fairlie DP, Hansford KA, Cooper MA, Giri R, Schreiber V, Joseph SR, Simpson F, Barnett TC, Johansson J, Dankers W, Harris J, Wells TJ, Kapetanovic R, Sweet MJ, Latomanski EA, Newton HJ, Guérillot RJR, Hachani A, Stinear TP, Ong SY, Chandran Y, Hartland EL, Kobe B, Stow JL, Sauer-Eriksson AE, Begun J, Kling JC, Blumenthal A. Inhibition of the master regulator of Listeria monocytogenes virulence enables bacterial clearance from spacious replication vacuoles in infected macrophages. PLoS Pathog 2022; 18:e1010166. [PMID: 35007292 PMCID: PMC8746789 DOI: 10.1371/journal.ppat.1010166] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 12/01/2021] [Indexed: 02/04/2023] Open
Abstract
A hallmark of Listeria (L.) monocytogenes pathogenesis is bacterial escape from maturing entry vacuoles, which is required for rapid bacterial replication in the host cell cytoplasm and cell-to-cell spread. The bacterial transcriptional activator PrfA controls expression of key virulence factors that enable exploitation of this intracellular niche. The transcriptional activity of PrfA within infected host cells is controlled by allosteric coactivation. Inhibitory occupation of the coactivator site has been shown to impair PrfA functions, but consequences of PrfA inhibition for L. monocytogenes infection and pathogenesis are unknown. Here we report the crystal structure of PrfA with a small molecule inhibitor occupying the coactivator site at 2.0 Å resolution. Using molecular imaging and infection studies in macrophages, we demonstrate that PrfA inhibition prevents the vacuolar escape of L. monocytogenes and enables extensive bacterial replication inside spacious vacuoles. In contrast to previously described spacious Listeria-containing vacuoles, which have been implicated in supporting chronic infection, PrfA inhibition facilitated progressive clearance of intracellular L. monocytogenes from spacious vacuoles through lysosomal degradation. Thus, inhibitory occupation of the PrfA coactivator site facilitates formation of a transient intravacuolar L. monocytogenes replication niche that licenses macrophages to effectively eliminate intracellular bacteria. Our findings encourage further exploration of PrfA as a potential target for antimicrobials and highlight that intra-vacuolar residence of L. monocytogenes in macrophages is not inevitably tied to bacterial persistence.
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Affiliation(s)
- Thao Thanh Tran
- The University of Queensland Diamantina Institute, Brisbane, Australia
| | | | | | - Rachel F. Rollo
- The University of Queensland Diamantina Institute, Brisbane, Australia
| | | | | | - Tam T. K. Nguyen
- The University of Queensland Diamantina Institute, Brisbane, Australia
| | | | - Lalith K. Kummari
- The University of Queensland School of Chemistry and Molecular Biosciences and Australian Infectious Diseases Research Centre, Brisbane, Australia
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
| | - Orry J. K. Wyer
- The University of Queensland Diamantina Institute, Brisbane, Australia
| | - Katharine M. Irvine
- ARC Centre of Excellence in Advanced Molecular Imaging, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
| | | | - Annette Gross
- The University of Queensland Diamantina Institute, Brisbane, Australia
| | - Darren Brown
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
| | - Jeffrey Y. W. Mak
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
- ARC Centre of Excellence in Advanced Molecular Imaging, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
| | - David P. Fairlie
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
- ARC Centre of Excellence in Advanced Molecular Imaging, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
| | - Karl A. Hansford
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
| | - Matthew A. Cooper
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
| | - Rabina Giri
- Mater Research Institute – The University of Queensland, Brisbane, Australia
| | - Veronika Schreiber
- Mater Research Institute – The University of Queensland, Brisbane, Australia
| | - Shannon R. Joseph
- The University of Queensland Diamantina Institute, Brisbane, Australia
| | - Fiona Simpson
- The University of Queensland Diamantina Institute, Brisbane, Australia
| | - Timothy C. Barnett
- Wesfarmers Centre for Vaccines and Infectious Diseases, Telethon Kids Institute, University of Western Australia, Nedlands, Australia
| | | | - Wendy Dankers
- Department of Medicine, School of Clinical Sciences at Monash Health, Faculty of Medicine, Nursing & Health Sciences, Monash University, Clayton, Australia
| | - James Harris
- Department of Medicine, School of Clinical Sciences at Monash Health, Faculty of Medicine, Nursing & Health Sciences, Monash University, Clayton, Australia
| | - Timothy J. Wells
- The University of Queensland Diamantina Institute, Brisbane, Australia
| | - Ronan Kapetanovic
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
| | - Matthew J. Sweet
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
| | - Eleanor A. Latomanski
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Hayley J. Newton
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Romain J. R. Guérillot
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Abderrahman Hachani
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Timothy P. Stinear
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Sze Ying Ong
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research and Department of Molecular and Translational Science, Monash University, Melbourne, Australia
| | - Yogeswari Chandran
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research and Department of Molecular and Translational Science, Monash University, Melbourne, Australia
| | - Elizabeth L. Hartland
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research and Department of Molecular and Translational Science, Monash University, Melbourne, Australia
| | - Bostjan Kobe
- The University of Queensland School of Chemistry and Molecular Biosciences and Australian Infectious Diseases Research Centre, Brisbane, Australia
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
| | - Jennifer L. Stow
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
| | | | - Jakob Begun
- Mater Research Institute – The University of Queensland, Brisbane, Australia
| | - Jessica C. Kling
- The University of Queensland Diamantina Institute, Brisbane, Australia
| | - Antje Blumenthal
- The University of Queensland Diamantina Institute, Brisbane, Australia
- * E-mail:
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Voth K, Pasricha S, Chung IYW, Wibawa RR, Zainudin ENHE, Hartland EL, Cygler M. Structural and Functional Characterization of Legionella pneumophila Effector MavL. Biomolecules 2021; 11:biom11121802. [PMID: 34944446 PMCID: PMC8699189 DOI: 10.3390/biom11121802] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 11/25/2021] [Accepted: 11/27/2021] [Indexed: 11/23/2022] Open
Abstract
Legionella pneumophila is a Gram-negative intracellular pathogen that causes Legionnaires’ disease in elderly or immunocompromised individuals. This bacterium relies on the Dot/Icm (Defective in organelle trafficking/Intracellular multiplication) Type IV Secretion System (T4SS) and a large (>330) set of effector proteins to colonize the host cell. The structural variability of these effectors allows them to disrupt many host processes. Herein, we report the crystal structure of MavL to 2.65 Å resolution. MavL adopts an ADP-ribosyltransferase (ART) fold and contains the distinctive ligand-binding cleft of ART proteins. Indeed, MavL binds ADP-ribose with Kd of 13 µM. Structural overlay of MavL with poly-(ADP-ribose) glycohydrolases (PARGs) revealed a pair of aspartate residues in MavL that align with the catalytic glutamates in PARGs. MavL also aligns with ADP-ribose “reader” proteins (proteins that recognize ADP-ribose). Since no glycohydrolase activity was observed when incubated in the presence of ADP-ribosylated PARP1, MavL may play a role as a signaling protein that binds ADP-ribose. An interaction between MavL and the mammalian ubiquitin-conjugating enzyme UBE2Q1 was revealed by yeast two-hybrid and co-immunoprecipitation experiments. This work provides structural and molecular insights to guide biochemical studies aimed at elucidating the function of MavL. Our findings support the notion that ubiquitination and ADP-ribosylation are global modifications exploited by L. pneumophila.
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Affiliation(s)
- Kevin Voth
- Department of Biochemistry, Microbiology & Immunology, University of Saskatchewan, 107 Wiggins Road, Saskatoon, SK S7N 5E5, Canada; (K.V.); (I.Y.W.C.)
| | - Shivani Pasricha
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton 3168, Australia; (S.P.); (R.R.W.)
| | - Ivy Yeuk Wah Chung
- Department of Biochemistry, Microbiology & Immunology, University of Saskatchewan, 107 Wiggins Road, Saskatoon, SK S7N 5E5, Canada; (K.V.); (I.Y.W.C.)
| | - Rachelia R. Wibawa
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton 3168, Australia; (S.P.); (R.R.W.)
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne 3000, Australia;
| | - Engku Nuraishah Huda E. Zainudin
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne 3000, Australia;
| | - Elizabeth L. Hartland
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton 3168, Australia; (S.P.); (R.R.W.)
- Department of Molecular and Translational Science, Monash University, Clayton 3168, Australia
- Correspondence: (E.L.H.); (M.C.)
| | - Miroslaw Cygler
- Department of Biochemistry, Microbiology & Immunology, University of Saskatchewan, 107 Wiggins Road, Saskatoon, SK S7N 5E5, Canada; (K.V.); (I.Y.W.C.)
- Correspondence: (E.L.H.); (M.C.)
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Hartland EL. Emerging methods in cellular microbiology. Cell Microbiol 2021; 23:e13369. [PMID: 34160866 DOI: 10.1111/cmi.13369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Elizabeth L Hartland
- 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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9
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Giogha C, Scott NE, Wong Fok Lung T, Pollock GL, Harper M, Goddard-Borger ED, Pearson JS, Hartland EL. NleB2 from enteropathogenic Escherichia coli is a novel arginine-glucose transferase effector. PLoS Pathog 2021; 17:e1009658. [PMID: 34133469 PMCID: PMC8238200 DOI: 10.1371/journal.ppat.1009658] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 06/28/2021] [Accepted: 05/20/2021] [Indexed: 12/12/2022] Open
Abstract
During infection, enteropathogenic Escherichia coli (EPEC) and enterohaemorrhagic E. coli (EHEC) directly manipulate various aspects of host cell function through the translocation of type III secretion system (T3SS) effector proteins directly into the host cell. Many T3SS effector proteins are enzymes that mediate post-translational modifications of host proteins, such as the glycosyltransferase NleB1, which transfers a single N-acetylglucosamine (GlcNAc) to arginine residues, creating an Arg-GlcNAc linkage. NleB1 glycosylates death-domain containing proteins including FADD, TRADD and RIPK1 to block host cell death. The NleB1 paralogue, NleB2, is found in many EPEC and EHEC strains but to date its enzymatic activity has not been described. Using in vitro glycosylation assays combined with mass spectrometry, we found that NleB2 can utilize multiple sugar donors including UDP-glucose, UDP-GlcNAc and UDP-galactose during glycosylation of the death domain protein, RIPK1. Sugar donor competition assays demonstrated that UDP-glucose was the preferred substrate of NleB2 and peptide sequencing identified the glycosylation site within RIPK1 as Arg603, indicating that NleB2 catalyses arginine glucosylation. We also confirmed that NleB2 catalysed arginine-hexose modification of Flag-RIPK1 during infection of HEK293T cells with EPEC E2348/69. Using site-directed mutagenesis and in vitro glycosylation assays, we identified that residue Ser252 in NleB2 contributes to the specificity of this distinct catalytic activity. Substitution of Ser252 in NleB2 to Gly, or substitution of the corresponding Gly255 in NleB1 to Ser switches sugar donor preference between UDP-GlcNAc and UDP-glucose. However, this switch did not affect the ability of the NleB variants to inhibit inflammatory or cell death signalling during HeLa cell transfection or EPEC infection. NleB2 is thus the first identified bacterial Arg-glucose transferase that, similar to the NleB1 Arg-GlcNAc transferase, inhibits host protein function by arginine glycosylation. Bacterial gut pathogens including enteropathogenic E. coli (EPEC) and enterohaemorrhagic E. coli (EHEC), manipulate host cell function by using a type III secretion system to inject ‘effector’ proteins directly into the host cell cytoplasm. We and others have shown that many of these effectors are novel enzymes, including NleB1, which transfers a single N-acetylglucosamine (GlcNAc) sugar to arginine residues, mediating Arg-GlcNAc glycosylation. Here, we found that a close homologue of NleB1 that is also present in EPEC and EHEC termed NleB2, uses a different sugar during glycosylation. We demonstrated that in contrast to NleB1, the preferred nucleotide-sugar substrate of NleB2 is UDP-glucose and we identified the amino acid residue within NleB2 that dictates this unique catalytic activity. Substitution of this residue in NleB2 and NleB1 switches the sugar donor usage of these enzymes but does not affect their ability to inhibit host cell signalling. Thus, NleB2 is the first identified bacterial arginine-glucose transferase, an activity which has previously only been described in plants and algae.
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Affiliation(s)
- Cristina Giogha
- 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
| | - Nichollas E. Scott
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Tania Wong Fok Lung
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Georgina L. Pollock
- 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
| | - Marina Harper
- Department of Microbiology, Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| | - Ethan D. Goddard-Borger
- ACRF Chemical Biology Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia
| | - Jaclyn S. Pearson
- 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
- Department of Microbiology, Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| | - Elizabeth L. Hartland
- 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
- * E-mail:
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10
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Ong SY, Schuelein R, Wibawa RR, Thomas DW, Handoko Y, Freytag S, Bahlo M, Simpson KJ, Hartland EL. Genome-wide genetic screen identifies host ubiquitination as important for Legionella pneumophila Dot/Icm effector translocation. Cell Microbiol 2021; 23:e13368. [PMID: 34041837 DOI: 10.1111/cmi.13368] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 05/20/2021] [Accepted: 05/24/2021] [Indexed: 11/30/2022]
Abstract
The Dot/Icm system of Legionella pneumophila is essential for virulence and delivers a large repertoire of effectors into infected host cells to create the Legionella containing vacuole. Since the secretion of effectors via the Dot/Icm system does not occur in the absence of host cells, we hypothesised that host factors actively participate in Dot/Icm effector translocation. Here we employed a high-throughput, genome-wide siRNA screen to systematically test the effect of silencing 18,120 human genes on translocation of the Dot/Icm effector, RalF, into HeLa cells. For the primary screen, we found that silencing of 119 genes led to increased translocation of RalF, while silencing of 321 genes resulted in decreased translocation. Following secondary screening, 70 genes were successfully validated as 'high confidence' targets. Gene set enrichment analysis of siRNAs leading to decreased RalF translocation, showed that ubiquitination was the most highly overrepresented category in the pathway analysis. We further showed that two host factors, the E2 ubiquitin-conjugating enzyme, UBE2E1, and the E3 ubiquitin ligase, CUL7, were important for supporting Dot/Icm translocation and L. pneumophila intracellular replication. In summary, we identified host ubiquitin pathways as important for the efficiency of Dot/Icm effector translocation by L. pneumophila, suggesting that host-derived ubiquitin-conjugating enzymes and ubiquitin ligases participate in the translocation of Legionella effector proteins and influence intracellular persistence and survival.
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Affiliation(s)
- Sze Ying Ong
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, Victoria, Australia
| | - Ralf Schuelein
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Rachelia R Wibawa
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, Victoria, Australia
| | - Daniel W Thomas
- Victorian Centre for Functional Genomics, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
| | - Yanny Handoko
- Victorian Centre for Functional Genomics, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
| | - Saskia Freytag
- Division of Population Health and Immunity, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia
| | - Melanie Bahlo
- Division of Population Health and Immunity, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia
| | - Kaylene J Simpson
- Victorian Centre for Functional Genomics, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia.,Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Victoria, Australia
| | - Elizabeth L Hartland
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, Victoria, Australia.,Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia.,Department of Molecular and Translational Science, Monash University, Clayton, Victoria, Australia
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11
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Chung IYW, Li L, Tyurin O, Gagarinova A, Wibawa R, Li P, Hartland EL, Cygler M. Structural and functional study of Legionella pneumophila effector RavA. Protein Sci 2021; 30:940-955. [PMID: 33660322 DOI: 10.1002/pro.4057] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 02/15/2021] [Accepted: 02/20/2021] [Indexed: 01/20/2023]
Abstract
Legionella pneumophila is an intracellular pathogen that causes Legionnaire's disease in humans. This bacterium can be found in freshwater environments as a free-living organism, but it is also an intracellular parasite of protozoa. Human infection occurs when inhaled aerosolized pathogen comes into contact with the alveolar mucosa and replicates in alveolar macrophages. Legionella enters the host cell by phagocytosis and redirects the Legionella-containing phagosomes from the phagocytic maturation pathway. These nascent phagosomes fuse with ER-derived secretory vesicles and membranes forming the Legionella-containing vacuole. Legionella subverts many host cellular processes by secreting over 300 effector proteins into the host cell via the Dot/Icm type IV secretion system. The cellular function for many Dot/Icm effectors is still unknown. Here, we present a structural and functional study of L. pneumophila effector RavA (Lpg0008). Structural analysis revealed that the RavA consists of four ~85 residue long α-helical domains with similar folds, which show only a low level of structural similarity to other protein domains. The ~90 residues long C-terminal segment is predicted to be natively unfolded. We show that during L. pneumophila infection of human cells, RavA localizes to the Golgi apparatus and to the plasma membrane. The same localization is observed when RavA is expressed in human cells. The localization signal resides within the C-terminal sequence C409 WTSFCGLF417 . Yeast-two-hybrid screen using RavA as bait identified RAB11A as a potential binding partner. RavA is present in L. pneumophila strains but only distant homologs are found in other Legionella species, where the number of repeats varies.
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Affiliation(s)
- Ivy Y W Chung
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Lei Li
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Oleg Tyurin
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.,Symvivo Corporation, Burnaby, British Columbia, Canada
| | - Alla Gagarinova
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Raissa Wibawa
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia.,Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, and Department of Molecular and Translational Science, Monash University, Clayton, Australia
| | - Pengfei Li
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia.,Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, and Department of Molecular and Translational Science, Monash University, Clayton, Australia
| | - Elizabeth L Hartland
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia.,Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, and Department of Molecular and Translational Science, Monash University, Clayton, Australia
| | - Miroslaw Cygler
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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12
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Abstract
Chronic recurrent multifocal osteomyelitis (CRMO) is an autoinflammatory bone disease mediated by the inflammatory cytokine, IL-1β. Although IL-1β is known as the key driver of bone lesions in CRMO, the signaling events leading to pathogenic levels of the cytokine are not fully understood. Using a genetic mouse model of CRMO, Dasari et al. find a role for the nonreceptor spleen tyrosine kinase (SYK) in upstream signaling leading to IL-1β up-regulation. Their findings suggest that SYK may constitute a new therapeutic target for CRMO.
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Affiliation(s)
- Elizabeth L Hartland
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research and Department of Molecular and Translational Science, Monash University, Clayton, Victoria 3168, Australia.
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13
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Gan J, Giogha C, Hartland EL. Molecular mechanisms employed by enteric bacterial pathogens to antagonise host innate immunity. Curr Opin Microbiol 2020; 59:58-64. [PMID: 32862049 DOI: 10.1016/j.mib.2020.07.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 07/25/2020] [Accepted: 07/27/2020] [Indexed: 12/13/2022]
Abstract
Many Gram-negative enteric pathogens, including enteropathogenic and enterohemorrhagic Escherichia coli (EPEC and EHEC), Salmonella, Shigella, and Yersinia species have evolved strategies to combat host defence mechanisms. Critical bacterial virulence factors, which often include but are not limited to type III secreted effector proteins, are deployed to cooperatively interfere with key host defence pathways. Recent studies in this area have not only contributed to our knowledge of bacterial pathogenesis, but have also shed light on the host pathways that are critical for controlling bacterial infection. In this review, we summarise recent breakthroughs in our understanding of the mechanisms utilised by enteric bacterial pathogens to rewire critical host innate immune responses, including cell death and inflammatory signaling and cell-intrinsic anti-microbial responses such as xenophagy.
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Affiliation(s)
- Jiyao Gan
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Victoria, Australia; Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, Victoria, Australia
| | - Cristina Giogha
- 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
| | - Elizabeth L Hartland
- 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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14
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Li P, Vassiliadis D, Ong SY, Bennett-Wood V, Sugimoto C, Yamagishi J, Hartland EL, Pasricha S. Legionella pneumophila Infection Rewires the Acanthamoeba castellanii Transcriptome, Highlighting a Class of Sirtuin Genes. Front Cell Infect Microbiol 2020; 10:428. [PMID: 32974218 PMCID: PMC7468528 DOI: 10.3389/fcimb.2020.00428] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Accepted: 07/14/2020] [Indexed: 12/13/2022] Open
Abstract
Legionella pneumophila is an environmental bacterium that has evolved to survive predation by soil and water amoebae such as Acanthamoeba castellanii, and this has inadvertently led to the ability of L. pneumophila to survive and replicate in human cells. L. pneumophila causes Legionnaire's Disease, with human exposure occurring via the inhalation of water aerosols containing both amoebae and the bacteria. These aerosols originate from aquatic biofilms found in artifical water sources, such as air-conditioning cooling towers and humidifiers. In these man-made environments, A. castellanii supports L. pneumophila intracellular replication, thereby promoting persistence and dissemination of the bacteria and providing protection from external stress. Despite this close evolutionary relationship, very little is known about how A. castellanii responds to L. pneumophila infection. In this study, we examined the global transcriptional response of A. castellanii to L. pneumophila infection. We compared A. castellanii infected with wild type L. pneumophila to A. castellanii infected with an isogenic ΔdotA mutant strain, which is unable to replicate intracellularly. We showed that A. castellanii underwent clear morphological and transcriptional rewiring over the course of L. pneumophila infection. Through improved annotation of the A. castellanii genome, we determined that these transcriptional changes primarily involved biological processes utilizing small GTPases, including cellular transport, signaling, metabolism and replication. In addition, a number of sirtuin-encoding genes in A. castellanii were found to be conserved and upregulated during L. pneumophila infection. Silencing of sirtuin gene, sir6f (ACA1_153540) resulted in the inhibition of A. castellanii cell proliferation during infection and reduced L. pneumophila replication. Overall our findings identified several biological pathways in amoebae that may support L. pneumophila replication and A. castellanii proliferation in environmental conditions.
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Affiliation(s)
- Pengfei Li
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, VIC, Australia.,Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia
| | - Dane Vassiliadis
- Cancer Research Division, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
| | - Sze Ying Ong
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, VIC, Australia
| | - Vicki Bennett-Wood
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia
| | - Chihiro Sugimoto
- Global Station for Zoonosis Control, GI-CoRE, Hokkaido University, Sapporo, Japan.,Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Junya Yamagishi
- Global Station for Zoonosis Control, GI-CoRE, Hokkaido University, Sapporo, Japan.,Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Elizabeth L Hartland
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, VIC, Australia.,Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia.,Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan.,Department of Molecular and Translational Science, Monash University, Clayton, VIC, Australia
| | - Shivani Pasricha
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, VIC, Australia.,Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia
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15
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Gan J, Scott NE, Newson JPM, Wibawa RR, Wong Fok Lung T, Pollock GL, Ng GZ, van Driel I, Pearson JS, Hartland EL, Giogha C. The Salmonella Effector SseK3 Targets Small Rab GTPases. Front Cell Infect Microbiol 2020; 10:419. [PMID: 32974215 PMCID: PMC7466453 DOI: 10.3389/fcimb.2020.00419] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 07/08/2020] [Indexed: 01/10/2023] Open
Abstract
During infection, Salmonella species inject multiple type III secretion system (T3SS) effector proteins into host cells that mediate invasion and subsequent intracellular replication. At early stages of infection, Salmonella exploits key regulators of host intracellular vesicle transport, including the small GTPases Rab5 and Rab7, to subvert host endocytic vesicle trafficking and establish the Salmonella-containing vacuole (SCV). At later stages of intracellular replication, interactions of the SCV with Rab GTPases are less well defined. Here we report that Rab1, Rab5, and Rab11 are modified at later stages of Salmonella infection by SseK3, an arginine N-acetylglucosamine (GlcNAc) transferase effector translocated via the Salmonella pathogenicity island 2 (SPI-2) type III secretion system. SseK3 modified arginines at positions 74, 82, and 111 within Rab1 and this modification occurred independently of Rab1 nucleotide binding. SseK3 exhibited Golgi localization that was independent of its glycosyltransferase activity but Arg-GlcNAc transferase activity was required for inhibition of alkaline phosphatase secretion in transfected cells. While SseK3 had a modest effect on SEAP secretion during infection of HeLa229 cells, inhibition of IL-1 and GM-CSF cytokine secretion was only observed upon over-expression of SseK3 during infection of RAW264.7 cells. Our results suggest that, in addition to targeting death receptor signaling, SseK3 may contribute to Salmonella infection by interfering with the activity of key Rab GTPases.
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Affiliation(s)
- Jiyao Gan
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, VIC, Australia.,Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia
| | - Nichollas E Scott
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia
| | - Joshua P M Newson
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia
| | - Rachelia R Wibawa
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, VIC, Australia.,Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia
| | - Tania Wong Fok Lung
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia
| | - Georgina L Pollock
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, VIC, Australia
| | - Garrett Z Ng
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC, Australia
| | - Ian van Driel
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC, Australia
| | - Jaclyn S Pearson
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, VIC, Australia.,Department of Molecular and Translational Science, Monash University, Clayton, VIC, Australia
| | - Elizabeth L Hartland
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, VIC, Australia.,Department of Molecular and Translational Science, Monash University, Clayton, VIC, Australia
| | - Cristina Giogha
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, VIC, Australia.,Department of Molecular and Translational Science, Monash University, Clayton, VIC, Australia
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16
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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17
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Oppy CC, Jebeli L, Kuba M, Oates CV, Strugnell R, Edgington-Mitchell LE, Valvano MA, Hartland EL, Newton HJ, Scott NE. Loss of O-Linked Protein Glycosylation in Burkholderia cenocepacia Impairs Biofilm Formation and Siderophore Activity and Alters Transcriptional Regulators. mSphere 2019; 4:e00660-19. [PMID: 31722994 PMCID: PMC6854043 DOI: 10.1128/msphere.00660-19] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 10/24/2019] [Indexed: 02/07/2023] Open
Abstract
O-linked protein glycosylation is a conserved feature of the Burkholderia genus. The addition of the trisaccharide β-Gal-(1,3)-α-GalNAc-(1,3)-β-GalNAc to membrane exported proteins in Burkholderia cenocepacia is required for bacterial fitness and resistance to environmental stress. However, the underlying causes of the defects observed in the absence of glycosylation are unclear. Using proteomics, luciferase reporter assays, and DNA cross-linking, we demonstrate the loss of glycosylation leads to changes in transcriptional regulation of multiple proteins, including the repression of the master quorum CepR/I. These proteomic and transcriptional alterations lead to the abolition of biofilm formation and defects in siderophore activity. Surprisingly, the abundance of most of the known glycosylated proteins did not significantly change in the glycosylation-defective mutants, except for BCAL1086 and BCAL2974, which were found in reduced amounts, suggesting they could be degraded. However, the loss of these two proteins was not responsible for driving the proteomic alterations, biofilm formation, or siderophore activity. Together, our results show that loss of glycosylation in B. cenocepacia results in a global cell reprogramming via alteration of the transcriptional regulatory systems, which cannot be explained by the abundance changes in known B. cenocepacia glycoproteins.IMPORTANCE Protein glycosylation is increasingly recognized as a common posttranslational protein modification in bacterial species. Despite this commonality, our understanding of the role of most glycosylation systems in bacterial physiology and pathogenesis is incomplete. In this work, we investigated the effect of the disruption of O-linked glycosylation in the opportunistic pathogen Burkholderia cenocepacia using a combination of proteomic, molecular, and phenotypic assays. We find that in contrast to recent findings on the N-linked glycosylation systems of Campylobacter jejuni, O-linked glycosylation does not appear to play a role in proteome stabilization of most glycoproteins. Our results reveal that loss of glycosylation in B. cenocepacia strains leads to global proteome and transcriptional changes, including the repression of the quorum-sensing regulator cepR (BCAM1868) gene. These alterations lead to dramatic phenotypic changes in glycosylation-null strains, which are paralleled by both global proteomic and transcriptional alterations, which do not appear to directly result from the loss of glycosylation per se. This research unravels the pleiotropic effects of O-linked glycosylation in B. cenocepacia, demonstrating that its loss does not simply affect the stability of the glycoproteome, but also interferes with transcription and the broader proteome.
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Affiliation(s)
- Cameron C Oppy
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
- Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Victoria, Australia
| | - Leila Jebeli
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Miku Kuba
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Clare V Oates
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Richard Strugnell
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Laura E Edgington-Mitchell
- Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Victoria, Australia
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
- Department of Oral and Maxillofacial Surgery, New York University College of Dentistry, Bluestone Center for Clinical Research, New York, New York, USA
| | - Miguel A Valvano
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast, United Kingdom
- Department of Microbiology and Immunology, University of Western Ontario, London, Ontario, Canada
| | - Elizabeth L Hartland
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, 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
| | - Hayley J Newton
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Nichollas E Scott
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
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18
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Newson JPM, Scott NE, Yeuk Wah Chung I, Wong Fok Lung T, Giogha C, Gan J, Wang N, Strugnell RA, Brown NF, Cygler M, Pearson JS, Hartland EL. Salmonella Effectors SseK1 and SseK3 Target Death Domain Proteins in the TNF and TRAIL Signaling Pathways. Mol Cell Proteomics 2019; 18:1138-1156. [PMID: 30902834 PMCID: PMC6553940 DOI: 10.1074/mcp.ra118.001093] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 02/13/2019] [Indexed: 01/09/2023] Open
Abstract
Strains of Salmonella utilize two distinct type three secretion systems to deliver effector proteins directly into host cells. The Salmonella effectors SseK1 and SseK3 are arginine glycosyltransferases that modify mammalian death domain containing proteins with N-acetyl glucosamine (GlcNAc) when overexpressed ectopically or as recombinant protein fusions. Here, we combined Arg-GlcNAc glycopeptide immunoprecipitation and mass spectrometry to identify host proteins GlcNAcylated by endogenous levels of SseK1 and SseK3 during Salmonella infection. We observed that SseK1 modified the mammalian signaling protein TRADD, but not FADD as previously reported. Overexpression of SseK1 greatly broadened substrate specificity, whereas ectopic co-expression of SseK1 and TRADD increased the range of modified arginine residues within the death domain of TRADD. In contrast, endogenous levels of SseK3 resulted in modification of the death domains of receptors of the mammalian TNF superfamily, TNFR1 and TRAILR, at residues Arg376 and Arg293 respectively. Structural studies on SseK3 showed that the enzyme displays a classic GT-A glycosyltransferase fold and binds UDP-GlcNAc in a narrow and deep cleft with the GlcNAc facing the surface. Together our data suggest that salmonellae carrying sseK1 and sseK3 employ the glycosyltransferase effectors to antagonise different components of death receptor signaling.
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Affiliation(s)
- Joshua P M Newson
- From the ‡Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Nichollas E Scott
- From the ‡Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Ivy Yeuk Wah Chung
- §Department of Biochemistry, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Tania Wong Fok Lung
- From the ‡Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Cristina Giogha
- ¶Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, Victoria, Australia
| | - Jiyao Gan
- From the ‡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, Victoria, Australia
| | - Nancy Wang
- From the ‡Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Richard A Strugnell
- From the ‡Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Nathaniel F Brown
- **Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
| | - Miroslaw Cygler
- §Department of Biochemistry, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Jaclyn S Pearson
- ¶Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, Victoria, Australia
| | - Elizabeth L Hartland
- From the ‡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, Victoria, Australia
- ‖Department of Molecular and Translational Science, Monash University, Clayton, Victoria, Australia
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19
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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: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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20
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Affiliation(s)
- Hayley J Newton
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia
| | - Elizabeth L Hartland
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, VIC, Australia.,Department of Molecular and Translational Science, Monash University, Clayton, VIC, Australia
| | - Matthias P Machner
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
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21
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Schuelein R, Spencer H, Dagley LF, Li PF, Luo L, Stow JL, Abraham G, Naderer T, Gomez-Valero L, Buchrieser C, Sugimoto C, Yamagishi J, Webb AI, Pasricha S, Hartland EL. Targeting of RNA Polymerase II by a nuclear Legionella pneumophila Dot/Icm effector SnpL. Cell Microbiol 2018; 20:e12852. [PMID: 29691989 DOI: 10.1111/cmi.12852] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 03/24/2018] [Accepted: 04/11/2018] [Indexed: 12/28/2022]
Abstract
The intracellular pathogen Legionella pneumophila influences numerous eukaryotic cellular processes through the Dot/Icm-dependent translocation of more than 300 effector proteins into the host cell. Although many translocated effectors localise to the Legionella replicative vacuole, other effectors can affect remote intracellular sites. Following infection, a subset of effector proteins localises to the nucleus where they subvert host cell transcriptional responses to infection. Here, we identified Lpw27461 (Lpp2587), Lpg2519 as a new nuclear-localised effector that we have termed SnpL. Upon ectopic expression or during L. pneumophila infection, SnpL showed strong nuclear localisation by immunofluorescence microscopy but was excluded from nucleoli. Using immunoprecipitation and mass spectrometry, we determined the host-binding partner of SnpL as the eukaryotic transcription elongation factor, Suppressor of Ty5 (SUPT5H)/Spt5. SUPT5H is an evolutionarily conserved component of the DRB sensitivity-inducing factor complex that regulates RNA Polymerase II dependent mRNA processing and transcription elongation. Protein interaction studies showed that SnpL bound to the central Kyprides, Ouzounis, Woese motif region of SUPT5H. Ectopic expression of SnpL led to massive upregulation of host gene expression and macrophage cell death. The activity of SnpL further highlights the ability of L. pneumophila to control fundamental eukaryotic processes such as transcription that, in the case of SnpL, leads to global upregulation of host gene expression.
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Affiliation(s)
- Ralf Schuelein
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Hugh Spencer
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Laura F Dagley
- The Walter and Eliza Hall Institute of Medical Research and Department of Medical Biology, University of Melbourne, Parkville, Australia
| | - Peng Fei Li
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia.,Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, Australia
| | - Lin Luo
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
| | - Jennifer L Stow
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
| | - Gilu Abraham
- Biomedicine Discovery Institute and Department of Biochemistry & Molecular Biology, Monash University, Clayton, Australia
| | - Thomas Naderer
- Biomedicine Discovery Institute and Department of Biochemistry & Molecular Biology, Monash University, Clayton, Australia
| | - Laura Gomez-Valero
- Institut Pasteur, Biologie des Bactéries Intracellulaires, Paris, France.,CNRS UMR 3525, Paris, France
| | - Carmen Buchrieser
- Institut Pasteur, Biologie des Bactéries Intracellulaires, Paris, France.,CNRS UMR 3525, Paris, France
| | - Chihiro Sugimoto
- Global Station for Zoonosis Control, GI-CoRE, Hokkaido University, Sapporo, Hokkaido, Japan.,Research Center for Zoonosis Control, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Junya Yamagishi
- Global Station for Zoonosis Control, GI-CoRE, Hokkaido University, Sapporo, Hokkaido, Japan.,Research Center for Zoonosis Control, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Andrew I Webb
- The Walter and Eliza Hall Institute of Medical Research and Department of Medical Biology, University of Melbourne, Parkville, Australia
| | - Shivani Pasricha
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia.,Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, Australia
| | - Elizabeth L Hartland
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia.,Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, Australia.,Institut Pasteur, Biologie des Bactéries Intracellulaires, Paris, France.,Department of Molecular and Translational Science, Monash University, Clayton, Australia
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22
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Srikhanta YN, Gorrell RJ, Power PM, Tsyganov K, Boitano M, Clark TA, Korlach J, Hartland EL, Jennings MP, Kwok T. Methylomic and phenotypic analysis of the ModH5 phasevarion of Helicobacter pylori. Sci Rep 2017; 7:16140. [PMID: 29170397 PMCID: PMC5700931 DOI: 10.1038/s41598-017-15721-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Accepted: 10/31/2017] [Indexed: 12/20/2022] Open
Abstract
The Helicobacter pylori phase variable gene modH, typified by gene HP1522 in strain 26695, encodes a N6-adenosine type III DNA methyltransferase. Our previous studies identified multiple strain-specific modH variants (modH1 – modH19) and showed that phase variation of modH5 in H. pylori P12 influenced expression of motility-associated genes and outer membrane protein gene hopG. However, the ModH5 DNA recognition motif and the mechanism by which ModH5 controls gene expression were unknown. Here, using comparative single molecule real-time sequencing, we identify the DNA site methylated by ModH5 as 5′-Gm6ACC-3′. This motif is vastly underrepresented in H. pylori genomes, but overrepresented in a number of virulence genes, including motility-associated genes, and outer membrane protein genes. Motility and the number of flagella of H. pylori P12 wild-type were significantly higher than that of isogenic modH5 OFF or ΔmodH5 mutants, indicating that phase variable switching of modH5 expression plays a role in regulating H. pylori motility phenotypes. Using the flagellin A (flaA) gene as a model, we show that ModH5 modulates flaA promoter activity in a GACC methylation-dependent manner. These findings provide novel insights into the role of ModH5 in gene regulation and how it mediates epigenetic regulation of H. pylori motility.
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Affiliation(s)
- Yogitha N Srikhanta
- Department of Microbiology, Monash University, Clayton, 3800, Victoria, Australia.,Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Parkville, 3010, Victoria, Australia.,Infection and Immunity Program, Biomedicine Discovery Institute, Monash University, Clayton, 3800, Victoria, Australia
| | - Rebecca J Gorrell
- Department of Microbiology, Monash University, Clayton, 3800, Victoria, Australia.,Infection and Immunity Program, Biomedicine Discovery Institute, Monash University, Clayton, 3800, Victoria, Australia.,Department of Biochemistry and Molecular Biology, Monash University, Clayton, 3800, Victoria, Australia.,Cancer Program, Biomedicine Discovery Institute, Monash University, Clayton, 3800, Victoria, Australia
| | - Peter M Power
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, 4222, Australia
| | - Kirill Tsyganov
- Bioinformatics Platform, Monash University, Clayton, 3800, Victoria, Australia
| | | | | | | | - Elizabeth L Hartland
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Parkville, 3010, Victoria, Australia.,Department of Molecular and Translational Science, Hudson Institute of Medical Research, Monash University, Clayton, 3800, Victoria, Australia
| | - Michael P Jennings
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, 4222, Australia.
| | - Terry Kwok
- Department of Microbiology, Monash University, Clayton, 3800, Victoria, Australia. .,Infection and Immunity Program, Biomedicine Discovery Institute, Monash University, Clayton, 3800, Victoria, Australia. .,Department of Biochemistry and Molecular Biology, Monash University, Clayton, 3800, Victoria, Australia. .,Cancer Program, Biomedicine Discovery Institute, Monash University, Clayton, 3800, Victoria, Australia.
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23
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Scott NE, Hartland EL. Post-translational Mechanisms of Host Subversion by Bacterial Effectors. Trends Mol Med 2017; 23:1088-1102. [PMID: 29150361 DOI: 10.1016/j.molmed.2017.10.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2017] [Revised: 10/19/2017] [Accepted: 10/19/2017] [Indexed: 12/19/2022]
Abstract
Bacterial effector proteins are a specialized class of secreted proteins that are translocated directly into the host cytoplasm by bacterial pathogens. Effector proteins have diverse activities and targets, and many mediate post-translational modifications of host proteins. Effector proteins offer potential in novel biotechnological and medical applications as enzymes that may modify human proteins. Here, we discuss the mechanisms used by effectors to subvert the human host through blocking, blunting, or subverting immune mechanisms. This capacity allows bacteria to control host cell function to support pathogen survival, replication and dissemination to other hosts. In addition, we highlight that knowledge of effector protein activity may be used to develop chemical inhibitors as a new approach to treat bacterial infections.
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Affiliation(s)
- Nichollas E Scott
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne 3000, Australia
| | - Elizabeth L Hartland
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton 3168, Australia; Department of Molecular and Translational Science, Monash University, Clayton 3168, Australia.
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24
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Scott NE, Giogha C, Pollock GL, Kennedy CL, Webb AI, Williamson NA, Pearson JS, Hartland EL. The bacterial arginine glycosyltransferase effector NleB preferentially modifies Fas-associated death domain protein (FADD). J Biol Chem 2017; 292:17337-17350. [PMID: 28860194 DOI: 10.1074/jbc.m117.805036] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2017] [Revised: 08/28/2017] [Indexed: 01/01/2023] Open
Abstract
The inhibition of host innate immunity pathways is essential for the persistence of attaching and effacing pathogens such as enteropathogenic Escherichia coli (EPEC) and Citrobacter rodentium during mammalian infections. To subvert these pathways and suppress the antimicrobial response, attaching and effacing pathogens use type III secretion systems to introduce effectors targeting key signaling pathways in host cells. One such effector is the arginine glycosyltransferase NleB1 (NleBCR in C. rodentium) that modifies conserved arginine residues in death domain-containing host proteins with N-acetylglucosamine (GlcNAc), thereby blocking extrinsic apoptosis signaling. Ectopically expressed NleB1 modifies the host proteins Fas-associated via death domain (FADD), TNFRSF1A-associated via death domain (TRADD), and receptor-interacting serine/threonine protein kinase 1 (RIPK1). However, the full repertoire of arginine GlcNAcylation induced by pathogen-delivered NleB1 is unknown. Using an affinity proteomic approach for measuring arginine-GlcNAcylated glycopeptides, we assessed the global profile of arginine GlcNAcylation during ectopic expression of NleB1, EPEC infection in vitro, or C. rodentium infection in vivo NleB overexpression resulted in arginine GlcNAcylation of multiple host proteins. However, NleB delivery during EPEC and C. rodentium infection caused rapid and preferential modification of Arg117 in FADD. This FADD modification was extremely stable and insensitive to physiological temperatures, glycosidases, or host cell degradation. Despite its stability and effect on the inhibition of apoptosis, arginine GlcNAcylation did not elicit any proteomic changes, even in response to prolonged NleB1 expression. We conclude that, at normal levels of expression during bacterial infection, NleB1/NleBCR antagonizes death receptor-induced apoptosis of infected cells by modifying FADD in an irreversible manner.
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Affiliation(s)
- Nichollas E Scott
- From the Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne 3000, Australia,
| | - Cristina Giogha
- From the Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne 3000, Australia
| | - Georgina L Pollock
- From the Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne 3000, Australia
| | - Catherine L Kennedy
- From the Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne 3000, Australia
| | - Andrew I Webb
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Melbourne, Australia.,the Department of Medical Biology, University of Melbourne, Parkville, Victoria 3050, Australia, and
| | - Nicholas A Williamson
- Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Victoria 3010, Australia
| | - Jaclyn S Pearson
- From the Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne 3000, Australia
| | - Elizabeth L Hartland
- From the Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne 3000, Australia
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25
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Affiliation(s)
- Elizabeth L Hartland
- Elizabeth L. Hartland is in the Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, 792 Elizabeth Street, Melbourne 3000, Victoria, Australia
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26
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Pearson JS, Giogha C, Mühlen S, Nachbur U, Pham CLL, Zhang Y, Hildebrand JM, Oates CV, Lung TWF, Ingle D, Dagley LF, Bankovacki A, Petrie EJ, Schroeder GN, Crepin VF, Frankel G, Masters SL, Vince J, Murphy JM, Sunde M, Webb AI, Silke J, Hartland EL. EspL is a bacterial cysteine protease effector that cleaves RHIM proteins to block necroptosis and inflammation. Nat Microbiol 2017; 2:16258. [PMID: 28085133 DOI: 10.1038/nmicrobiol.2016.258] [Citation(s) in RCA: 111] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 11/28/2016] [Indexed: 11/09/2022]
Abstract
Cell death signalling pathways contribute to tissue homeostasis and provide innate protection from infection. Adaptor proteins such as receptor-interacting serine/threonine-protein kinase 1 (RIPK1), receptor-interacting serine/threonine-protein kinase 3 (RIPK3), TIR-domain-containing adapter-inducing interferon-β (TRIF) and Z-DNA-binding protein 1 (ZBP1)/DNA-dependent activator of IFN-regulatory factors (DAI) that contain receptor-interacting protein (RIP) homotypic interaction motifs (RHIM) play a key role in cell death and inflammatory signalling1-3. RHIM-dependent interactions help drive a caspase-independent form of cell death termed necroptosis4,5. Here, we report that the bacterial pathogen enteropathogenic Escherichia coli (EPEC) uses the type III secretion system (T3SS) effector EspL to degrade the RHIM-containing proteins RIPK1, RIPK3, TRIF and ZBP1/DAI during infection. This requires a previously unrecognized tripartite cysteine protease motif in EspL (Cys47, His131, Asp153) that cleaves within the RHIM of these proteins. Bacterial infection and/or ectopic expression of EspL leads to rapid inactivation of RIPK1, RIPK3, TRIF and ZBP1/DAI and inhibition of tumour necrosis factor (TNF), lipopolysaccharide or polyinosinic:polycytidylic acid (poly(I:C))-induced necroptosis and inflammatory signalling. Furthermore, EPEC infection inhibits TNF-induced phosphorylation and plasma membrane localization of mixed lineage kinase domain-like pseudokinase (MLKL). In vivo, EspL cysteine protease activity contributes to persistent colonization of mice by the EPEC-like mouse pathogen Citrobacter rodentium. The activity of EspL defines a family of T3SS cysteine protease effectors found in a range of bacteria and reveals a mechanism by which gastrointestinal pathogens directly target RHIM-dependent inflammatory and necroptotic signalling pathways.
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Affiliation(s)
- Jaclyn S Pearson
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne 3000, Australia
| | - Cristina Giogha
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne 3000, Australia
| | - Sabrina Mühlen
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne 3000, Australia.,Department of Molecular Infection Biology, Helmholtz-Centre for Infection Research, 38124 Braunschweig, Germany
| | - Ueli Nachbur
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Melbourne, Australia.,Department of Medical Biology, University of Melbourne, Victoria 3010, Australia
| | - Chi L L Pham
- Discipline of Pharmacology, School of Medical Sciences, University of Sydney, New South Wales 2006, Australia
| | - Ying Zhang
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne 3000, Australia
| | - Joanne M Hildebrand
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Melbourne, Australia.,Department of Medical Biology, University of Melbourne, Victoria 3010, Australia
| | - Clare V Oates
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne 3000, Australia
| | - Tania Wong Fok Lung
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne 3000, Australia
| | - Danielle Ingle
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne 3000, Australia.,Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute and Centre for Systems Genomics, University of Melbourne, Victoria 3010, Australia
| | - Laura F Dagley
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Melbourne, Australia.,Department of Medical Biology, University of Melbourne, Victoria 3010, Australia
| | - Aleksandra Bankovacki
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Melbourne, Australia.,Department of Medical Biology, University of Melbourne, Victoria 3010, Australia
| | - Emma J Petrie
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Melbourne, Australia.,Department of Medical Biology, University of Melbourne, Victoria 3010, Australia
| | - Gunnar N Schroeder
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College London, SW7 2AZ, UK.,Centre for Experimental Medicine, Queen's University Belfast, BT9 7BL, UK
| | - Valerie F Crepin
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College London, SW7 2AZ, UK
| | - Gad Frankel
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College London, SW7 2AZ, UK
| | - Seth L Masters
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Melbourne, Australia.,Department of Medical Biology, University of Melbourne, Victoria 3010, Australia
| | - James Vince
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Melbourne, Australia.,Department of Medical Biology, University of Melbourne, Victoria 3010, Australia
| | - James M Murphy
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Melbourne, Australia.,Department of Medical Biology, University of Melbourne, Victoria 3010, Australia
| | - Margaret Sunde
- Discipline of Pharmacology, School of Medical Sciences, University of Sydney, New South Wales 2006, Australia
| | - Andrew I Webb
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Melbourne, Australia.,Department of Medical Biology, University of Melbourne, Victoria 3010, Australia
| | - John Silke
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Melbourne, Australia.,Department of Medical Biology, University of Melbourne, Victoria 3010, Australia
| | - Elizabeth L Hartland
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne 3000, Australia
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27
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Affiliation(s)
- Jaclyn S. Pearson
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria 3010, Australia; , , ,
| | - Cristina Giogha
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria 3010, Australia; , , ,
| | - Tania Wong Fok Lung
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria 3010, Australia; , , ,
| | - Elizabeth L. Hartland
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria 3010, Australia; , , ,
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28
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Fiene A, Baqi Y, Malik EM, Newton P, Li W, Lee SY, Hartland EL, Müller CE. Inhibitors for the bacterial ectonucleotidase Lp1NTPDase from Legionella pneumophila. Bioorg Med Chem 2016; 24:4363-4371. [DOI: 10.1016/j.bmc.2016.07.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 07/15/2016] [Indexed: 12/29/2022]
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29
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Zhang Y, Mühlen S, Oates CV, Pearson JS, Hartland EL. Identification of a Distinct Substrate-binding Domain in the Bacterial Cysteine Methyltransferase Effectors NleE and OspZ. J Biol Chem 2016; 291:20149-62. [PMID: 27445336 DOI: 10.1074/jbc.m116.734079] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2016] [Indexed: 02/02/2023] Open
Abstract
The type III secretion system effector protein NleE from enteropathogenic Escherichia coli plays a key role in the inhibition of NF-κB activation during infection. NleE inactivates the ubiquitin chain binding activity of host proteins TAK1-binding proteins 2 and 3 (TAB2 and TAB3) by modifying the Npl4 zinc finger domain through S-adenosyl methionine-dependent cysteine methylation. Using yeast two-hybrid protein interaction studies, we found that a conserved region between amino acids 34 and 52 of NleE, in particular the motif (49)GITR(52), was critical for TAB2 and TAB3 binding. NleE mutants lacking (49)GITR(52) were unable to methylate TAB3, and wild type NleE but not NleE(49AAAA52) where each of GITR was replaced with alanine restored the ability of an nleE mutant to inhibit IL-8 production during infection. Another NleE target, ZRANB3, also associated with NleE through the (49)GITR(52) motif. Ectopic expression of an N-terminal fragment of NleE (NleE(34-52)) in HeLa cells showed competitive inhibition of wild type NleE in the suppression of IL-8 secretion during enteropathogenic E. coli infection. Similar results were observed for the NleE homologue OspZ from Shigella flexneri 6 that also bound TAB3 through the (49)GITR(52) motif and decreased IL-8 transcription through modification of TAB3. In summary, we have identified a unique substrate-binding motif in NleE and OspZ that is required for the ability to inhibit the host inflammatory response.
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Affiliation(s)
- Ying Zhang
- From the Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria 3000, Australia
| | - Sabrina Mühlen
- From the Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria 3000, Australia
| | - Clare V Oates
- From the Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria 3000, Australia
| | - Jaclyn S Pearson
- From the Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria 3000, Australia
| | - Elizabeth L Hartland
- From the Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria 3000, Australia
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30
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Giogha C, Lung TWF, Mühlen S, Pearson JS, Hartland EL. Substrate recognition by the zinc metalloprotease effector NleC from enteropathogenic Escherichia coli. Cell Microbiol 2015; 17:1766-78. [PMID: 26096513 DOI: 10.1111/cmi.12469] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Revised: 06/04/2015] [Accepted: 06/06/2015] [Indexed: 12/01/2022]
Abstract
Upon infection of epithelial cells, enteropathogenic Escherichia coli suppresses host cell inflammatory signalling in a type III secretion system (T3SS) dependent manner. Two key T3SS effector proteins involved in this response are NleE and NleC. NleC is a zinc metalloprotease effector that degrades the p65 subunit of NF-κB. Although the site of p65 cleavage by NleC is now well described, other areas of interaction have not been precisely defined. Here we constructed overlapping truncations of p65 to identify regions required for NleC cleavage. We determined that NleC cleaved both p65 and p50 within the Rel homology domain (RHD) and that two motifs, E22IIE25 and P177VLS180 , within the RHD of p65 were important for recognition and binding by NleC. Alanine substitution of one or both of these motifs protected p65 from binding and degradation by NleC. The E22IIE25 and P177VLS180 motifs were located within the structurally distinct N-terminal subdomain of the RHD involved in DNA binding by p65 on adjacent, parallel strands. Although these motifs have not been recognized previously, both were needed for the correct localization and function of p65. In summary, this work has identified two regions of p65 within the RHD needed for binding and cleavage by NleC and provides further insight into the molecular basis of substrate recognition by a T3SS effector.
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Affiliation(s)
- Cristina Giogha
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, VIC, 3000, Australia
| | - Tania Wong Fok Lung
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, VIC, 3000, Australia
| | - Sabrina Mühlen
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, VIC, 3000, Australia
| | - Jaclyn S Pearson
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, VIC, 3000, Australia
| | - Elizabeth L Hartland
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, VIC, 3000, Australia
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31
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Nachbur U, Stafford CA, Bankovacki A, Zhan Y, Lindqvist LM, Fiil BK, Khakham Y, Ko HJ, Sandow JJ, Falk H, Holien JK, Chau D, Hildebrand J, Vince JE, Sharp PP, Webb AI, Jackman KA, Mühlen S, Kennedy CL, Lowes KN, Murphy JM, Gyrd-Hansen M, Parker MW, Hartland EL, Lew AM, Huang DCS, Lessene G, Silke J. A RIPK2 inhibitor delays NOD signalling events yet prevents inflammatory cytokine production. Nat Commun 2015; 6:6442. [PMID: 25778803 DOI: 10.1038/ncomms7442] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 01/29/2015] [Indexed: 12/22/2022] Open
Abstract
Intracellular nucleotide binding and oligomerization domain (NOD) receptors recognize antigens including bacterial peptidoglycans and initiate immune responses by triggering the production of pro-inflammatory cytokines through activating NF-κB and MAP kinases. Receptor interacting protein kinase 2 (RIPK2) is critical for NOD-mediated NF-κB activation and cytokine production. Here we develop and characterize a selective RIPK2 kinase inhibitor, WEHI-345, which delays RIPK2 ubiquitylation and NF-κB activation downstream of NOD engagement. Despite only delaying NF-κB activation on NOD stimulation, WEHI-345 prevents cytokine production in vitro and in vivo and ameliorates experimental autoimmune encephalomyelitis in mice. Our study highlights the importance of the kinase activity of RIPK2 for proper immune responses and demonstrates the therapeutic potential of inhibiting RIPK2 in NOD-driven inflammatory diseases.
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Affiliation(s)
- Ueli Nachbur
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Che A Stafford
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Aleksandra Bankovacki
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Yifan Zhan
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Lisa M Lindqvist
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Berthe K Fiil
- 1] Department of Disease Biology, Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark [2] Ludwig Institute for Cancer Research, Nuffield Department of Clinical Medicine, University of Oxford, Oxford OX3 7DQ, UK
| | - Yelena Khakham
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Hyun-Ja Ko
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Jarrod J Sandow
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Hendrik Falk
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia [3] Cancer Therapeutics CRC, Bundoora, Victoria 3083, Australia
| | - Jessica K Holien
- ACRF Rational Drug Discovery Centre, St Vincent's Institute of Medical Research, 9 Princes Street, Fitzroy, Victoria 3065, Australia
| | - Diep Chau
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Joanne Hildebrand
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - James E Vince
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Phillip P Sharp
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Andrew I Webb
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Katherine A Jackman
- The Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, Austin Campus, 245 Burgundy Street, Heidelberg, Victoria 3084, Australia
| | - Sabrina Mühlen
- Department of Microbiology and Immunology, University of Melbourne, Victoria 3010, Australia
| | - Catherine L Kennedy
- Department of Microbiology and Immunology, University of Melbourne, Victoria 3010, Australia
| | - Kym N Lowes
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - James M Murphy
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Mads Gyrd-Hansen
- 1] Department of Disease Biology, Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark [2] Ludwig Institute for Cancer Research, Nuffield Department of Clinical Medicine, University of Oxford, Oxford OX3 7DQ, UK
| | - Michael W Parker
- 1] ACRF Rational Drug Discovery Centre, St Vincent's Institute of Medical Research, 9 Princes Street, Fitzroy, Victoria 3065, Australia [2] Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Elizabeth L Hartland
- Department of Microbiology and Immunology, University of Melbourne, Victoria 3010, Australia
| | - Andrew M Lew
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - David C S Huang
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Guillaume Lessene
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - John Silke
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
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King NP, Newton P, Schuelein R, Brown DL, Petru M, Zarsky V, Dolezal P, Luo L, Bugarcic A, Stanley AC, Murray RZ, Collins BM, Teasdale RD, Hartland EL, Stow JL. Soluble NSF attachment protein receptor molecular mimicry by a Legionella pneumophila Dot/Icm effector. Cell Microbiol 2015; 17:767-84. [PMID: 25488819 DOI: 10.1111/cmi.12405] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 11/10/2014] [Accepted: 12/02/2014] [Indexed: 01/17/2023]
Abstract
Upon infection, Legionella pneumophila uses the Dot/Icm type IV secretion system to translocate effector proteins from the Legionella-containing vacuole (LCV) into the host cell cytoplasm. The effectors target a wide array of host cellular processes that aid LCV biogenesis, including the manipulation of membrane trafficking. In this study, we used a hidden Markov model screen to identify two novel, non-eukaryotic soluble NSF attachment protein receptor (SNARE) homologs: the bacterial Legionella SNARE effector A (LseA) and viral SNARE homolog A proteins. We characterized LseA as a Dot/Icm effector of L. pneumophila, which has close homology to the Qc-SNARE subfamily. The lseA gene was present in multiple sequenced L. pneumophila strains including Corby and was well distributed among L. pneumophila clinical and environmental isolates. Employing a variety of biochemical, cell biological and microbiological techniques, we found that farnesylated LseA localized to membranes associated with the Golgi complex in mammalian cells and LseA interacted with a subset of Qa-, Qb- and R-SNAREs in host cells. Our results suggested that LseA acts as a SNARE protein and has the potential to regulate or mediate membrane fusion events in Golgi-associated pathways.
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Affiliation(s)
- Nathan P King
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld., Australia
| | - Patrice Newton
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Vic., Australia
| | - Ralf Schuelein
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Vic., Australia
| | - Darren L Brown
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld., Australia
| | - Marketa Petru
- Department of Parasitology, Charles University in Prague, Czech Republic
| | - Vojtech Zarsky
- Department of Parasitology, Charles University in Prague, Czech Republic
| | - Pavel Dolezal
- Department of Parasitology, Charles University in Prague, Czech Republic
| | - Lin Luo
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld., Australia
| | - Andrea Bugarcic
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld., Australia
| | - Amanda C Stanley
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld., Australia
| | - Rachael Z Murray
- Tissue Repair and Regeneration Program, Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, Qld., Australia
| | - Brett M Collins
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld., Australia
| | - Rohan D Teasdale
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld., Australia
| | - Elizabeth L Hartland
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Vic., Australia
| | - Jennifer L Stow
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld., Australia
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Abstract
Infections with enteropathogenic Escherichia coli (EPEC) are remarkably devoid of gut inflammation and necrotic damage compared to infections caused by invasive pathogens such as Salmonella and Shigella. Recently, we observed that EPEC blocks cell death using the type III secretion system (T3SS) effector NleB. NleB mediated post-translational modification of death domain containing adaptor proteins by the covalent attachment of N-acetylglucosamine (GlcNAc) to a conserved arginine in the death domain. N-linked glycosylation of arginine has not previously been reported in mammalian cell biology and the precise biochemistry of this modification is not yet defined. Although the addition of a single GlcNAc to arginine is a seemingly slight alteration, the impact of NleB is considerable as arginine in this location is critical for death domain interactions and death receptor induced apoptosis. Hence, by blocking cell death, NleB promotes enterocyte survival and thereby prolongs EPEC attachment to the gut epithelium.
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Affiliation(s)
- Jaclyn S Pearson
- Department of Microbiology and Immunology; University of Melbourne at the Peter Doherty Institute for Infection and Immunity; Melbourne, Australia
| | - Elizabeth L Hartland
- Department of Microbiology and Immunology; University of Melbourne at the Peter Doherty Institute for Infection and Immunity; Melbourne, Australia,Correspondence to: Elizabeth L Hartland;
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Young JC, Clements A, Lang AE, Garnett JA, Munera D, Arbeloa A, Pearson J, Hartland EL, Matthews SJ, Mousnier A, Barry DJ, Way M, Schlosser A, Aktories K, Frankel G. The Escherichia coli effector EspJ blocks Src kinase activity via amidation and ADP ribosylation. Nat Commun 2014; 5:5887. [PMID: 25523213 PMCID: PMC4284639 DOI: 10.1038/ncomms6887] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Accepted: 11/17/2014] [Indexed: 12/01/2022] Open
Abstract
The hallmark of enteropathogenic Escherichia coli (EPEC) infection is the formation of actin-rich pedestal-like structures, which are generated following phosphorylation of the bacterial effector Tir by cellular Src and Abl family tyrosine kinases. This leads to recruitment of the Nck-WIP-N-WASP complex that triggers Arp2/3-dependent actin polymerization in the host cell. The same phosphorylation-mediated signalling network is also assembled downstream of the Vaccinia virus protein A36 and the phagocytic Fc-gamma receptor FcγRIIa. Here we report that the EPEC type-III secretion system effector EspJ inhibits autophosphorylation of Src and phosphorylation of the Src substrates Tir and FcγRIIa. Consistent with this, EspJ inhibits actin polymerization downstream of EPEC, Vaccinia virus and opsonized red blood cells. We identify EspJ as a unique adenosine diphosphate (ADP) ribosyltransferase that directly inhibits Src kinase by simultaneous amidation and ADP ribosylation of the conserved kinase-domain residue, Src E310, resulting in glutamine-ADP ribose.
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Affiliation(s)
- Joanna C. Young
- MRC Centre for Molecular Bacteriology and Infection, Imperial College, SW7 2AZ London, UK
| | - Abigail Clements
- MRC Centre for Molecular Bacteriology and Infection, Imperial College, SW7 2AZ London, UK
| | - Alexander E. Lang
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Freiburg, D-79104 Freiburg, Germany
| | - James A. Garnett
- Centre for Structural Biology, Imperial College, SW7 2AZ London, UK
| | - Diana Munera
- MRC Centre for Molecular Bacteriology and Infection, Imperial College, SW7 2AZ London, UK
| | - Ana Arbeloa
- MRC Centre for Molecular Bacteriology and Infection, Imperial College, SW7 2AZ London, UK
| | - Jaclyn Pearson
- Department of Microbiology and Immunology, University of Melbourne, at the Peter Doherty Institute for Infection and Immunity, Melbourne Victoria 3010, Australia
| | - Elizabeth L. Hartland
- Department of Microbiology and Immunology, University of Melbourne, at the Peter Doherty Institute for Infection and Immunity, Melbourne Victoria 3010, Australia
| | | | - Aurelie Mousnier
- MRC Centre for Molecular Bacteriology and Infection, Imperial College, SW7 2AZ London, UK
| | - David J. Barry
- Cell Motility Laboratory, Cancer Research UK, London Research Institute, 44 Lincoln’s Inn Fields, London WC2A 3LY, UK
| | - Michael Way
- Cell Motility Laboratory, Cancer Research UK, London Research Institute, 44 Lincoln’s Inn Fields, London WC2A 3LY, UK
| | - Andreas Schlosser
- Rudolf Virchow Center for Experimental Biomedicine, University of Wuerzburg, 97080 Würzburg, Germany
| | - Klaus Aktories
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Freiburg, D-79104 Freiburg, Germany
- Centre for Biological Signalling Studies (BIOSS), University of Freiburg, D-79104 Freiburg, Germany
| | - Gad Frankel
- MRC Centre for Molecular Bacteriology and Infection, Imperial College, SW7 2AZ London, UK
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35
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Sansom FM, Ralton JE, Sernee MF, Cohen AM, Hooker DJ, Hartland EL, Naderer T, McConville MJ. Golgi-located NTPDase1 of Leishmania major is required for lipophosphoglycan elongation and normal lesion development whereas secreted NTPDase2 is dispensable for virulence. PLoS Negl Trop Dis 2014; 8:e3402. [PMID: 25521752 PMCID: PMC4270689 DOI: 10.1371/journal.pntd.0003402] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Accepted: 11/10/2014] [Indexed: 12/27/2022] Open
Abstract
Parasitic protozoa, such as Leishmania species, are thought to express a number of surface and secreted nucleoside triphosphate diphosphohydrolases (NTPDases) which hydrolyze a broad range of nucleoside tri- and diphosphates. However, the functional significance of NTPDases in parasite virulence is poorly defined. The Leishmania major genome was found to contain two putative NTPDases, termed LmNTPDase1 and 2, with predicted NTPDase catalytic domains and either an N-terminal signal sequence and/or transmembrane domain, respectively. Expression of both proteins as C-terminal GFP fusion proteins revealed that LmNTPDase1 was exclusively targeted to the Golgi apparatus, while LmNTPDase2 was predominantly secreted. An L. major LmNTPDase1 null mutant displayed increased sensitivity to serum complement lysis and exhibited a lag in lesion development when infections in susceptible BALB/c mice were initiated with promastigotes, but not with the obligate intracellular amastigote stage. This phenotype is characteristic of L. major strains lacking lipophosphoglycan (LPG), the major surface glycoconjugate of promastigote stages. Biochemical studies showed that the L. major NTPDase1 null mutant synthesized normal levels of LPG that was structurally identical to wild type LPG, with the exception of having shorter phosphoglycan chains. These data suggest that the Golgi-localized NTPase1 is involved in regulating the normal sugar-nucleotide dependent elongation of LPG and assembly of protective surface glycocalyx. In contrast, deletion of the gene encoding LmNTPDase2 had no measurable impact on parasite virulence in BALB/c mice. These data suggest that the Leishmania major NTPDase enzymes have potentially important roles in the insect stage, but only play a transient or non-major role in pathogenesis in the mammalian host. Nucleoside triphosphate diphosphohydrolases (NTPDases) are a family of enzymes expressed in many eukaryotes, ranging from single-celled parasites to mammals. In mammals, NTPDases can have an immunomodulatory role, while in pathogenic protists cell-surface and secreted NTPDases are thought to be important virulence factors, although this has never been explicitly tested. In this study we have investigated the function of two NTPDases, termed LmNTPDase1 and LmNTPDase2, in Leishmania major parasites. We show that LmNTPDase 1 and LmNTPDase 2 are differentially targeted to the Golgi apparatus and secreted, respectively. A Leishmania major mutant lacking the Golgi LmNTPDase1 exhibited a delayed capacity to induce lesions in susceptible mice when promastigote (insect) stages were used to initiate infection, but not when amastigote (mammalian-infective) stages were used. Loss of promastigote infectivity in the LmNTPDase1 null mutant was associated with the synthesis and surface expression of lipophosphoglycan (LPG), with shorter glycan chains and increased sensitivity to complement-mediated lysis. In contrast, a null mutant lacking the secreted LmNTPDase2 did not exhibit any difference in virulence. Our results suggest that Leishmania major NTPDases have specific roles in regulating Golgi glycosylation pathways, and nucleoside salvage pathways in the insect stages, but do not appear to be required for virulence of the mammalian-infective stages.
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Affiliation(s)
- Fiona M. Sansom
- Department of Biochemistry and Molecular Biology, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Parkville, Victoria, Australia
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Victoria, Australia
- * E-mail:
| | - Julie E. Ralton
- Department of Biochemistry and Molecular Biology, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Parkville, Victoria, Australia
| | - M. Fleur Sernee
- Department of Biochemistry and Molecular Biology, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Parkville, Victoria, Australia
| | - Alice M. Cohen
- Department of Biochemistry and Molecular Biology, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Parkville, Victoria, Australia
| | - David J. Hooker
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, 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
| | - Thomas Naderer
- Department of Biochemistry and Molecular Biology, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Parkville, Victoria, Australia
| | - Malcolm J. McConville
- Department of Biochemistry and Molecular Biology, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Parkville, Victoria, Australia
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O'Donnell JA, Kennedy CL, Pellegrini M, Nowell CJ, Zhang JG, O'Reilly LA, Cengia L, Dias S, Masters SL, Hartland EL, Roberts AW, Gerlic M, Croker BA. Fas regulates neutrophil lifespan during viral and bacterial infection. J Leukoc Biol 2014; 97:321-6. [PMID: 25473101 DOI: 10.1189/jlb.3ab1113-594rr] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The regulation of neutrophil lifespan is critical for a circumscribed immune response. Neutrophils are sensitive to Fas/CD95 death receptor signaling in vitro, but it is unknown if Fas regulates neutrophil lifespan in vivo. We hypothesized that FasL-expressing CD8(+) T cells, which kill antigen-stimulated T cells during chronic viral infection, can also induce neutrophil death in tissues during infection. With the use of LysM-Cre Fas(fl/fl) mice, which lack Fas expression in macrophages and neutrophils, we show that Fas regulates neutrophil lifespan during lymphocytic choriomeningitis virus (LCMV) infection in the lung, peripheral blood, and spleen. Fas also contributed to the regulation of neutrophil numbers in the colon of Citrobacter rodentium-infected mice. To examine the effects of infection on Fas activation in neutrophils, we primed neutrophils with TLR ligands or IL-18, resulting in ablation of Fas death receptor signaling. These data provide the first in vivo genetic evidence that neutrophil lifespan is controlled by death receptor signaling and provide a mechanism to account for neutrophil resistance to Fas stimulation during infection.
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Affiliation(s)
- Joanne A O'Donnell
- *Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia; Department of Medical Biology and Faculty of Medicine, University of Melbourne, Parkville, Victoria, Australia; Department of Microbiology and Immunology, University of Melbourne at Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA; and Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Catherine L Kennedy
- *Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia; Department of Medical Biology and Faculty of Medicine, University of Melbourne, Parkville, Victoria, Australia; Department of Microbiology and Immunology, University of Melbourne at Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA; and Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Marc Pellegrini
- *Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia; Department of Medical Biology and Faculty of Medicine, University of Melbourne, Parkville, Victoria, Australia; Department of Microbiology and Immunology, University of Melbourne at Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA; and Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Cameron J Nowell
- *Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia; Department of Medical Biology and Faculty of Medicine, University of Melbourne, Parkville, Victoria, Australia; Department of Microbiology and Immunology, University of Melbourne at Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA; and Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Jian-Guo Zhang
- *Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia; Department of Medical Biology and Faculty of Medicine, University of Melbourne, Parkville, Victoria, Australia; Department of Microbiology and Immunology, University of Melbourne at Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA; and Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Lorraine A O'Reilly
- *Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia; Department of Medical Biology and Faculty of Medicine, University of Melbourne, Parkville, Victoria, Australia; Department of Microbiology and Immunology, University of Melbourne at Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA; and Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Louise Cengia
- *Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia; Department of Medical Biology and Faculty of Medicine, University of Melbourne, Parkville, Victoria, Australia; Department of Microbiology and Immunology, University of Melbourne at Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA; and Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Stuart Dias
- *Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia; Department of Medical Biology and Faculty of Medicine, University of Melbourne, Parkville, Victoria, Australia; Department of Microbiology and Immunology, University of Melbourne at Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA; and Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Seth L Masters
- *Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia; Department of Medical Biology and Faculty of Medicine, University of Melbourne, Parkville, Victoria, Australia; Department of Microbiology and Immunology, University of Melbourne at Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA; and Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Elizabeth L Hartland
- *Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia; Department of Medical Biology and Faculty of Medicine, University of Melbourne, Parkville, Victoria, Australia; Department of Microbiology and Immunology, University of Melbourne at Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA; and Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Andrew W Roberts
- *Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia; Department of Medical Biology and Faculty of Medicine, University of Melbourne, Parkville, Victoria, Australia; Department of Microbiology and Immunology, University of Melbourne at Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA; and Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Motti Gerlic
- *Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia; Department of Medical Biology and Faculty of Medicine, University of Melbourne, Parkville, Victoria, Australia; Department of Microbiology and Immunology, University of Melbourne at Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA; and Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ben A Croker
- *Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia; Department of Medical Biology and Faculty of Medicine, University of Melbourne, Parkville, Victoria, Australia; Department of Microbiology and Immunology, University of Melbourne at Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA; and Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
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37
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Pearson JS, Zhang Y, Newton HJ, Hartland EL. Post-modern pathogens: surprising activities of translocated effectors from E. coli and Legionella. Curr Opin Microbiol 2014; 23:73-9. [PMID: 25461576 DOI: 10.1016/j.mib.2014.11.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2014] [Revised: 11/04/2014] [Accepted: 11/06/2014] [Indexed: 11/16/2022]
Abstract
Many bacterial pathogens have the ability to manipulate cellular processes and interfere with host cell function through the translocation of bacterial 'effector' proteins. Dedicated protein secretion machines from Gram-negative pathogens, including type III, type IV and type VI secretion systems, inject virulence proteins into infected cells, altering normal cell physiology, including cell structure, metabolism, trafficking and signalling. While effectors were once thought to exert an effect simply by their localization and binding to host cell proteins, increasingly effectors are being recognised as enzymes, in some cases mediating highly novel post-translational modifications on host proteins. Here we highlight some of the more unusual activities of translocated effectors from enteropathogenic Escherichia coli and Legionella pneumophila.
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Affiliation(s)
- Jaclyn S Pearson
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Victoria 3000, Australia
| | - Ying Zhang
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Victoria 3000, Australia
| | - Hayley J Newton
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Victoria 3000, Australia
| | - Elizabeth L Hartland
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Victoria 3000, Australia.
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Gomez-Valero L, Rusniok C, Rolando M, Neou M, Dervins-Ravault D, Demirtas J, Rouy Z, Moore RJ, Chen H, Petty NK, Jarraud S, Etienne J, Steinert M, Heuner K, Gribaldo S, Médigue C, Glöckner G, Hartland EL, Buchrieser C. Comparative analyses of Legionella species identifies genetic features of strains causing Legionnaires’ disease. Genome Biol 2014. [PMID: 25370836 PMCID: PMC4256840 DOI: 10.1186/s13059-014-0505-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Background The genus Legionella comprises over 60 species. However, L. pneumophila and L. longbeachae alone cause over 95% of Legionnaires’ disease. To identify the genetic bases underlying the different capacities to cause disease we sequenced and compared the genomes of L. micdadei, L. hackeliae and L. fallonii (LLAP10), which are all rarely isolated from humans. Results We show that these Legionella species possess different virulence capacities in amoeba and macrophages, correlating with their occurrence in humans. Our comparative analysis of 11 Legionella genomes belonging to five species reveals highly heterogeneous genome content with over 60% representing species-specific genes; these comprise a complete prophage in L. micdadei, the first ever identified in a Legionella genome. Mobile elements are abundant in Legionella genomes; many encode type IV secretion systems for conjugative transfer, pointing to their importance for adaptation of the genus. The Dot/Icm secretion system is conserved, although the core set of substrates is small, as only 24 out of over 300 described Dot/Icm effector genes are present in all Legionella species. We also identified new eukaryotic motifs including thaumatin, synaptobrevin or clathrin/coatomer adaptine like domains. Conclusions Legionella genomes are highly dynamic due to a large mobilome mainly comprising type IV secretion systems, while a minority of core substrates is shared among the diverse species. Eukaryotic like proteins and motifs remain a hallmark of the genus Legionella. Key factors such as proteins involved in oxygen binding, iron storage, host membrane transport and certain Dot/Icm substrates are specific features of disease-related strains. Electronic supplementary material The online version of this article (doi:10.1186/s13059-014-0505-0) contains supplementary material, which is available to authorized users.
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Fung KY, Rahman T, Kennedy C, van Driel IR, Hartland EL. 59. Cytokine 2014. [DOI: 10.1016/j.cyto.2014.07.066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Wong Fok Lung T, Pearson JS, Schuelein R, Hartland EL. The cell death response to enteropathogenic Escherichia coli infection. Cell Microbiol 2014; 16:1736-45. [PMID: 25266336 DOI: 10.1111/cmi.12371] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Revised: 09/24/2014] [Accepted: 09/26/2014] [Indexed: 12/13/2022]
Abstract
Given the critical roles of inflammation and programmed cell death in fighting infection, it is not surprising that many bacterial pathogens have evolved strategies to inactivate these defences. The causative agent of infant diarrhoea, enteropathogenic Escherichia coli (EPEC), is an extracellular, intestinal pathogen that blocks both inflammation and programmed cell death. EPEC attaches to enterocytes, remains in the gut lumen and utilizes a type III secretion system (T3SS) to inject multiple virulence effector proteins directly into the infected cell, many of which subvert host antimicrobial processes through the disruption of signalling pathways. Recently, T3SS effector proteins from EPEC have been identified that inhibit death receptor-induced apoptosis. Here we review the mechanisms used by EPEC T3SS effectors to manipulate apoptosis and promote host cell survival and discuss the role of these activities during infection.
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Affiliation(s)
- Tania Wong Fok Lung
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, 3000, Australia
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Mousnier A, Schroeder GN, Stoneham CA, So EC, Garnett JA, Yu L, Matthews SJ, Choudhary JS, Hartland EL, Frankel G. A new method to determine in vivo interactomes reveals binding of the Legionella pneumophila effector PieE to multiple rab GTPases. mBio 2014; 5:e01148-14. [PMID: 25118235 PMCID: PMC4145681 DOI: 10.1128/mbio.01148-14] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 07/11/2014] [Indexed: 01/21/2023] Open
Abstract
UNLABELLED Legionella pneumophila, the causative agent of Legionnaires' disease, uses the Dot/Icm type IV secretion system (T4SS) to translocate more than 300 effectors into host cells, where they subvert host cell signaling. The function and host cell targets of most effectors remain unknown. PieE is a 69-kDa Dot/Icm effector containing three coiled-coil (CC) regions and 2 transmembrane (TM) helices followed by a fourth CC region. Here, we report that PieE dimerized by an interaction between CC3 and CC4. We found that ectopically expressed PieE localized to the endoplasmic reticulum (ER) and induced the formation of organized smooth ER, while following infection PieE localized to the Legionella-containing vacuole (LCV). To identify the physiological targets of PieE during infection, we established a new purification method for which we created an A549 cell line stably expressing the Escherichia coli biotin ligase BirA and infected the cells with L. pneumophila expressing PieE fused to a BirA-specific biotinylation site and a hexahistidine tag. Following tandem Ni(2+) nitrilotriacetic acid (NTA) and streptavidin affinity chromatography, the effector-target complexes were analyzed by mass spectrometry. This revealed interactions of PieE with multiple host cell proteins, including the Rab GTPases 1a, 1b, 2a, 5c, 6a, 7, and 10. Binding of the Rab GTPases, which was validated by yeast two-hybrid binding assays, was mediated by the PieE CC1 and CC2. In summary, using a novel, highly specific strategy to purify effector complexes from infected cells, which is widely applicable to other pathogens, we identified PieE as a multidomain LCV protein with promiscuous Rab GTPase-binding capacity. IMPORTANCE The respiratory pathogen Legionella pneumophila uses the Dot/Icm type IV secretion system to translocate more than 300 effector proteins into host cells. The function of most effectors in infection remains unknown. One of the bottlenecks for their characterization is the identification of target proteins. Frequently used in vitro approaches are not applicable to all effectors and suffer from high rates of false positives or missed interactions, as they are not performed in the context of an infection. Here, we determine key functional domains of the effector PieE and describe a new method to identify host cell targets under physiological infection conditions. Our approach, which is applicable to other pathogens, uncovered the interaction of PieE with several proteins involved in membrane trafficking, in particular Rab GTPases, revealing new details of the Legionella infection strategy and demonstrating the potential of this method to greatly advance our understanding of the molecular basis of infection.
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Affiliation(s)
- Aurélie Mousnier
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Gunnar N Schroeder
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Charlotte A Stoneham
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Ernest C So
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College London, London, United Kingdom
| | | | - Lu Yu
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | | | - Jyoti S Choudhary
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Elizabeth L Hartland
- Department of Microbiology and Immunology, University of Melbourne, at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Gad Frankel
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College London, London, United Kingdom
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Luo L, Wall AA, Yeo JC, Condon ND, Norwood SJ, Schoenwaelder S, Chen KW, Jackson S, Jenkins BJ, Hartland EL, Schroder K, Collins BM, Sweet MJ, Stow JL. Rab8a interacts directly with PI3Kγ to modulate TLR4-driven PI3K and mTOR signalling. Nat Commun 2014; 5:4407. [PMID: 25022365 DOI: 10.1038/ncomms5407] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 06/16/2014] [Indexed: 02/06/2023] Open
Abstract
Toll-like receptor 4 (TLR4) is activated by bacterial lipopolysaccharide (LPS) to mount innate immune responses. The TLR4-induced release of pro- and anti-inflammatory cytokines generates robust inflammatory responses, which must then be restrained to avoid disease. New mechanisms for the critical regulation of TLR-induced cytokine responses are still emerging. Here we find TLR4 complexes localized in LPS-induced dorsal ruffles on the surface of macrophages. We discover that the small GTPase Rab8a is enriched in these ruffles and recruits phosphatidylinositol 3-kinase (PI3Kγ) as an effector by interacting directly through its Ras-binding domain. Rab8a and PI3Kγ function to regulate Akt signalling generated by surface TLR4. Rab8a and PI3Kγ do not affect TLR4 endocytosis, but instead regulate mammalian target of rapamycin signalling as a mechanism for biasing the cytokine profile to constrain inflammation in innate immunity.
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Affiliation(s)
- Lin Luo
- 1] Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia [2]
| | - Adam A Wall
- 1] Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia [2]
| | - Jeremy C Yeo
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Nicholas D Condon
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Suzanne J Norwood
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Simone Schoenwaelder
- 1] Australian Centre for Blood Diseases, Monash University, Melbourne, Victoria 3004, Australia [2] Heart Research Institute & Charles Perkins Centre, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Kaiwen W Chen
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Shaun Jackson
- 1] Australian Centre for Blood Diseases, Monash University, Melbourne, Victoria 3004, Australia [2] Heart Research Institute & Charles Perkins Centre, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Brendan J Jenkins
- Centre for Innate Immunity and Infectious Diseases, MIMR-PHI Institute of Medical Research, Monash University, 27-31 Wright Street, Clayton, Victoria 3168, Australia
| | - Elizabeth L Hartland
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria 3010, Australia
| | - Kate Schroder
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Brett M Collins
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Matthew J Sweet
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Jennifer L Stow
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
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43
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Giogha C, Lung TWF, Pearson JS, Hartland EL. Inhibition of death receptor signaling by bacterial gut pathogens. Cytokine Growth Factor Rev 2014; 25:235-43. [DOI: 10.1016/j.cytogfr.2013.12.012] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Accepted: 12/18/2013] [Indexed: 12/22/2022]
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44
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Brown AS, Bourges D, Ang DK, Hartland EL, van Driel IR. CD8 subunit expression by plasmacytoid dendritic cells is variable, and does not define stable subsets. Mucosal Immunol 2014; 7:200-1. [PMID: 24192911 DOI: 10.1038/mi.2013.91] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- A S Brown
- The Department of Biochemistry and Molecular Biology, The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, Australia
| | - D Bourges
- The Department of Biochemistry and Molecular Biology, The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, Australia
| | - D K Ang
- The Department of Biochemistry and Molecular Biology, The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, Australia
| | - E L Hartland
- The Department of Microbiology and Immunology, The University of Melbourne, Parkville, Victoria, Australia
| | - I R van Driel
- The Department of Biochemistry and Molecular Biology, The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, Australia
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Pearson JS, Giogha C, Ong SY, Kennedy CL, Kelly M, Robinson KS, Wong T, Mansell A, Riedmaier P, Oates CVL, Zaid A, Mühlen S, Crepin VF, Marches O, Ang CS, Williamson NA, O’Reilly LA, Bankovacki A, Nachbur U, Infusini G, Webb AI, Silke J, Strasser A, Frankel G, Hartland EL. A type III effector antagonizes death receptor signalling during bacterial gut infection. Nature 2013; 501:247-51. [PMID: 24025841 PMCID: PMC3836246 DOI: 10.1038/nature12524] [Citation(s) in RCA: 209] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Accepted: 08/02/2013] [Indexed: 02/07/2023]
Abstract
Successful infection by enteric bacterial pathogens depends on the ability of the bacteria to colonize the gut, replicate in host tissues and disseminate to other hosts. Pathogens such as Salmonella, Shigella and enteropathogenic and enterohaemorrhagic (EPEC and EHEC, respectively) Escherichia coli use a type III secretion system (T3SS) to deliver virulence effector proteins into host cells during infection that promote colonization and interfere with antimicrobial host responses. Here we report that the T3SS effector NleB1 from EPEC binds to host cell death-domain-containing proteins and thereby inhibits death receptor signalling. Protein interaction studies identified FADD, TRADD and RIPK1 as binding partners of NleB1. NleB1 expressed ectopically or injected by the bacterial T3SS prevented Fas ligand or TNF-induced formation of the canonical death-inducing signalling complex (DISC) and proteolytic activation of caspase-8, an essential step in death-receptor-induced apoptosis. This inhibition depended on the N-acetylglucosamine transferase activity of NleB1, which specifically modified Arg 117 in the death domain of FADD. The importance of the death receptor apoptotic pathway to host defence was demonstrated using mice deficient in the FAS signalling pathway, which showed delayed clearance of the EPEC-like mouse pathogen Citrobacter rodentium and reversion to virulence of an nleB mutant. The activity of NleB suggests that EPEC and other attaching and effacing pathogens antagonize death-receptor-induced apoptosis of infected cells, thereby blocking a major antimicrobial host response.
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Affiliation(s)
- Jaclyn S Pearson
- Department of Microbiology and Immunology, University of Melbourne, Victoria 3010, Australia
| | - Cristina Giogha
- Department of Microbiology and Immunology, University of Melbourne, Victoria 3010, Australia
| | - Sze Ying Ong
- Department of Microbiology and Immunology, University of Melbourne, Victoria 3010, Australia
| | - Catherine L Kennedy
- Department of Microbiology and Immunology, University of Melbourne, Victoria 3010, Australia
| | - Michelle Kelly
- Department of Microbiology and Immunology, University of Melbourne, Victoria 3010, Australia
| | - Keith S Robinson
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College London, SW7 2AZ, UK
| | - Tania Wong
- Department of Microbiology and Immunology, University of Melbourne, Victoria 3010, Australia
| | - Ashley Mansell
- Centre for Innate Immunity and Infectious Diseases, Monash Institute of Medical Research, Victoria 3010, Australia
| | - Patrice Riedmaier
- Department of Microbiology and Immunology, University of Melbourne, Victoria 3010, Australia
| | - Clare VL Oates
- Department of Microbiology and Immunology, University of Melbourne, Victoria 3010, Australia
| | - Ali Zaid
- Department of Microbiology and Immunology, University of Melbourne, Victoria 3010, Australia
| | - Sabrina Mühlen
- Department of Microbiology and Immunology, University of Melbourne, Victoria 3010, Australia
| | - Valerie F Crepin
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College London, SW7 2AZ, UK
| | - Olivier Marches
- Centre for Immunology and Infectious Disease, Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London E1 2AT, UK
| | - Ching-Seng Ang
- Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Victoria 3010, Australia
| | - Nicholas A Williamson
- Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Victoria 3010, Australia
| | - Lorraine A O’Reilly
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
- Department of Medical Biology, University of Melbourne, Victoria 3010, Australia
| | - Aleksandra Bankovacki
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
| | - Ueli Nachbur
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
| | - Giuseppe Infusini
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
| | - Andrew I Webb
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
- Department of Medical Biology, University of Melbourne, Victoria 3010, Australia
| | - John Silke
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
- Department of Medical Biology, University of Melbourne, Victoria 3010, Australia
| | - Andreas Strasser
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
- Department of Medical Biology, University of Melbourne, Victoria 3010, Australia
| | - Gad Frankel
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College London, SW7 2AZ, UK
| | - Elizabeth L Hartland
- Department of Microbiology and Immunology, University of Melbourne, Victoria 3010, Australia
- Murdoch Children’s Research Institute, Royal Children’s Hospital, Parkville, Victoria 3052, Australia
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Yang J, Hocking DM, Cheng C, Dogovski C, Perugini MA, Holien JK, Parker MW, Hartland EL, Tauschek M, Robins-Browne RM. Disarming bacterial virulence through chemical inhibition of the DNA binding domain of an AraC-like transcriptional activator protein. J Biol Chem 2013; 288:31115-26. [PMID: 24019519 DOI: 10.1074/jbc.m113.503912] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The misuse of antibiotics during past decades has led to pervasive antibiotic resistance in bacteria. Hence, there is an urgent need for the development of new and alternative approaches to combat bacterial infections. In most bacterial pathogens the expression of virulence is tightly regulated at the transcriptional level. Therefore, targeting pathogens with drugs that interfere with virulence gene expression offers an effective alternative to conventional antimicrobial chemotherapy. Many Gram-negative intestinal pathogens produce AraC-like proteins that control the expression of genes required for infection. In this study we investigated the prototypical AraC-like virulence regulator, RegA, from the mouse attaching and effacing pathogen, Citrobacter rodentium, as a potential drug target. By screening a small molecule chemical library and chemical optimization, we identified two compounds that specifically inhibited the ability of RegA to activate its target promoters and thus reduced expression of a number of proteins required for virulence. Biophysical, biochemical, genetic, and computational analyses indicated that the more potent of these two compounds, which we named regacin, disrupts the DNA binding capacity of RegA by interacting with amino acid residues within a conserved region of the DNA binding domain. Oral administration of regacin to mice, commencing 15 min before or 12 h after oral inoculation with C. rodentium, caused highly significant attenuation of intestinal colonization by the mouse pathogen comparable to that of an isogenic regA-deletion mutant. These findings demonstrate that chemical inhibition of the DNA binding domains of transcriptional regulators is a viable strategy for the development of antimicrobial agents that target bacterial pathogens.
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Affiliation(s)
- Ji Yang
- From the Department of Microbiology and Immunology, The University of Melbourne, Victoria 3010
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47
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Hartland EL, Leong JM. Enteropathogenic and enterohemorrhagic E. coli: ecology, pathogenesis, and evolution. Front Cell Infect Microbiol 2013; 3:15. [PMID: 23641365 PMCID: PMC3639409 DOI: 10.3389/fcimb.2013.00015] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2013] [Accepted: 04/13/2013] [Indexed: 11/13/2022] Open
Affiliation(s)
- Elizabeth L. Hartland
- Department of Microbiology and Immunology, University of MelbourneParkville, VIC, Australia
- Murdoch Children's Research Institute, Royal Children's HospitalParkville, VIC, Australia
- *Correspondence:
| | - John M. Leong
- Department of Molecular Biology and Microbiology, Tufts University School of MedicineBoston, MA, USA
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Vogrin AJ, Mousnier A, Frankel G, Hartland EL. Subcellular localization of legionella Dot/Icm effectors. Methods Mol Biol 2013; 954:333-44. [PMID: 23150406 DOI: 10.1007/978-1-62703-161-5_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The translocation of effector proteins by the Dot/Icm type IV secretion system is central to the ability of Legionella pneumophila to persist and replicate within eukaryotic cells. The subcellular localization of translocated Dot/Icm proteins in host cells provides insight into their function. Through co-staining with host cell markers, effector proteins may be localized to specific subcellular compartments and membranes, which frequently reflects their host cell target and mechanism of action. In this chapter, we describe protocols to (1) localize effector proteins within cells by ectopic expression using green fluorescent protein fusions and (2) localize effector proteins within infected cells using epitope-tagged effector proteins and immuno-fluorescence microscopy.
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Affiliation(s)
- Adam J Vogrin
- Department of Microbiology and Immunology, University of Melbourne, Melbourne, VIC, Australia
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Abstract
Legionella pneumophila is an accidental respiratory pathogen of humans that provokes a robust inflammatory response upon infection. While most people exposed to L. pneumophila will clear the infection, certain groups with underlying susceptibility will develop Legionnaires' disease. Mice, like most humans, are inherently resistant to L. pneumophila and infection of most inbred strains reflects the response of immune competent people to L. pneumophila exposure. Hence, the use of mouse models of L. pneumophila infection has taught us a great deal about the innate and adaptive factors that lead to successful clearance of the pathogen and avoidance of Legionnaires' disease. At the same time, L. pneumophila has provided new insight into innate immunity in general and is now a model pathogen with which to study acute lung inflammation and inflammasome activation. This chapter will explore the history and use of the mouse model of L. pneumophila infection and examine what we know about the innate and adaptive factors that contribute to the control of L. pneumophila in the mouse lung.
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Affiliation(s)
- Andrew S Brown
- Department of Biochemistry and Molecular Biology and the Bio21 Institute, University of Melbourne, Victoria, 3010, Australia
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50
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Dolezal P, Aili M, Tong J, Jiang JH, Marobbio CM, Lee SF, Schuelein R, Belluzzo S, Binova E, Mousnier A, Frankel G, Giannuzzi G, Palmieri F, Gabriel K, Naderer T, Hartland EL, Lithgow T. Legionella pneumophila secretes a mitochondrial carrier protein during infection. PLoS Pathog 2012; 8:e1002459. [PMID: 22241989 PMCID: PMC3252375 DOI: 10.1371/journal.ppat.1002459] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Accepted: 11/09/2011] [Indexed: 12/25/2022] Open
Abstract
The Mitochondrial Carrier Family (MCF) is a signature group of integral membrane proteins that transport metabolites across the mitochondrial inner membrane in eukaryotes. MCF proteins are characterized by six transmembrane segments that assemble to form a highly-selective channel for metabolite transport. We discovered a novel MCF member, termed Legionellanucleotide carrier Protein (LncP), encoded in the genome of Legionella pneumophila, the causative agent of Legionnaire's disease. LncP was secreted via the bacterial Dot/Icm type IV secretion system into macrophages and assembled in the mitochondrial inner membrane. In a yeast cellular system, LncP induced a dominant-negative phenotype that was rescued by deleting an endogenous ATP carrier. Substrate transport studies on purified LncP reconstituted in liposomes revealed that it catalyzes unidirectional transport and exchange of ATP transport across membranes, thereby supporting a role for LncP as an ATP transporter. A hidden Markov model revealed further MCF proteins in the intracellular pathogens, Legionella longbeachae and Neorickettsia sennetsu, thereby challenging the notion that MCF proteins exist exclusively in eukaryotic organisms. Mitochondrial carrier proteins evolved during endosymbiosis to transport substrates across the mitochondrial inner membrane. As such the proteins are associated exclusively with eukaryotic organisms. Despite this, we identified putative mitochondrial carrier proteins in the genomes of different intracellular bacterial pathogens, including Legionella pneumophila, the causative agent of Legionnaire's disease. We named the mitochondrial carrier protein from L. pneumophila LncP and determined that the protein is translocated into host cells during infection by the bacterial Dot/Icm type IV secretion system. From there, LncP accesses the classical mitochondrial import pathway and is incorporated into the mitochondrial inner membrane as an integral membrane protein. Remarkably, LncP crosses five biological membranes to reach its final location. Biochemically, LncP is a unidirectional nucleotide transporter similar to Aac1 in yeast. Although not essential for intracellular replication, the high carriage rate of lncP among isolates of L. pneumophila suggests that the ability of the pathogen to manipulate mitochondrial ATP transport assists survival of the bacteria in an intracellular environment.
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Affiliation(s)
- Pavel Dolezal
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Australia
- Department of Parasitology, Charles University, Prague, Czech Republic
| | - Margareta Aili
- Department of Microbiology and Immunology, University of Melbourne, Parkville, Australia
| | - Janette Tong
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Australia
| | - Jhih-Hang Jiang
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Australia
- Department of Microbiology and Immunology, University of Melbourne, Parkville, Australia
| | - Carlo M. Marobbio
- Department of Pharmaco-Biology, Laboratory of Biochemistry and Molecular Biology, University of Bari, Bari, Italy
| | - Sau fung Lee
- Department of Microbiology and Immunology, University of Melbourne, Parkville, Australia
| | - Ralf Schuelein
- Department of Microbiology and Immunology, University of Melbourne, Parkville, Australia
| | - Simon Belluzzo
- Department of Microbiology and Immunology, University of Melbourne, Parkville, Australia
| | - Eva Binova
- Department of Tropical Medicine, 1st Faculty of Medicine, Charles University in Prague and Faculty Hospital Bulovka, Prague, Czech Republic
| | - Aurelie Mousnier
- Centre for Molecular Microbiology and Infection, Division of Cell and Molecular Biology, Imperial College London, London, United Kingdom
| | - Gad Frankel
- Centre for Molecular Microbiology and Infection, Division of Cell and Molecular Biology, Imperial College London, London, United Kingdom
| | - Giulia Giannuzzi
- Department of Pharmaco-Biology, Laboratory of Biochemistry and Molecular Biology, University of Bari, Bari, Italy
| | - Ferdinando Palmieri
- Department of Pharmaco-Biology, Laboratory of Biochemistry and Molecular Biology, University of Bari, Bari, Italy
| | - Kipros Gabriel
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Australia
| | - Thomas Naderer
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Australia
| | - Elizabeth L. Hartland
- Department of Microbiology and Immunology, University of Melbourne, Parkville, Australia
- * E-mail: (ELH); (TL)
| | - Trevor Lithgow
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Australia
- * E-mail: (ELH); (TL)
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