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Ge Z, Yuan P, Chen L, Chen J, Shen D, She Z, Lu Y. New Global Insights on the Regulation of the Biphasic Life Cycle and Virulence Via ClpP-Dependent Proteolysis in Legionella pneumophila. Mol Cell Proteomics 2022; 21:100233. [PMID: 35427813 PMCID: PMC9112007 DOI: 10.1016/j.mcpro.2022.100233] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 02/17/2022] [Accepted: 04/07/2022] [Indexed: 01/11/2023] Open
Abstract
Legionella pneumophila, an environmental bacterium that parasitizes protozoa, causes Legionnaires’ disease in humans that is characterized by severe pneumonia. This bacterium adopts a distinct biphasic life cycle consisting of a nonvirulent replicative phase and a virulent transmissive phase in response to different environmental conditions. Hence, the timely and fine-tuned expression of growth and virulence factors in a life cycle–dependent manner is crucial for survival and replication. Here, we report that the completion of the biphasic life cycle and bacterial pathogenesis is greatly dependent on the protein homeostasis regulated by caseinolytic protease P (ClpP)-dependent proteolysis. We characterized the ClpP-dependent dynamic profiles of the regulatory and substrate proteins during the biphasic life cycle of L. pneumophila using proteomic approaches and discovered that ClpP-dependent proteolysis specifically and conditionally degraded the substrate proteins, thereby directly playing a regulatory role or indirectly controlling cellular events via the regulatory proteins. We further observed that ClpP-dependent proteolysis is required to monitor the abundance of fatty acid biosynthesis–related protein Lpg0102/Lpg0361/Lpg0362 and SpoT for the normal regulation of L. pneumophila differentiation. We also found that the control of the biphasic life cycle and bacterial virulence is independent. Furthermore, the ClpP-dependent proteolysis of Dot/Icm (defect in organelle trafficking/intracellular multiplication) type IVB secretion system and effector proteins at a specific phase of the life cycle is essential for bacterial pathogenesis. Therefore, our findings provide novel insights on ClpP-dependent proteolysis, which spans a broad physiological spectrum involving key metabolic pathways that regulate the transition of the biphasic life cycle and bacterial virulence of L. pneumophila, facilitating adaptation to aquatic and intracellular niches. ClpP is the major determinant of biphasic life cycle–dependent protein turnover. ClpP-dependent proteolysis monitors SpoT abundance for cellular differentiation. ClpP-dependent regulation of life cycle and bacterial virulence is independent. ClpP-dependent proteolysis of T4BSS and effector proteins is vital for virulence.
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Affiliation(s)
- Zhenhuang Ge
- School of Chemistry, Sun Yat-sen University, Guangzhou, China; School of Life Sciences, Sun Yat-sen University, Guangzhou, China; Run Ze Laboratory for Gastrointestinal Microbiome Study, Sun Yat-sen University, Guangzhou, China
| | - Peibo Yuan
- Microbiome Medicine Center, Division of Laboratory Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Lingming Chen
- Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Junyi Chen
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China; Run Ze Laboratory for Gastrointestinal Microbiome Study, Sun Yat-sen University, Guangzhou, China
| | - Dong Shen
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Zhigang She
- School of Chemistry, Sun Yat-sen University, Guangzhou, China
| | - Yongjun Lu
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China; Run Ze Laboratory for Gastrointestinal Microbiome Study, Sun Yat-sen University, Guangzhou, China.
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Bonartsev AP, Voinova VV, Bonartseva GA. Poly(3-hydroxybutyrate) and Human Microbiota (Review). APPL BIOCHEM MICRO+ 2018. [DOI: 10.1134/s0003683818060066] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Mendis N, McBride P, Saoud J, Mani T, Faucher SP. The LetA/S two-component system regulates transcriptomic changes that are essential for the culturability of Legionella pneumophila in water. Sci Rep 2018; 8:6764. [PMID: 29712912 PMCID: PMC5928044 DOI: 10.1038/s41598-018-24263-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 03/07/2018] [Indexed: 11/13/2022] Open
Abstract
Surviving the nutrient-poor aquatic environment for extended periods of time is important for the transmission of various water-borne pathogens, including Legionella pneumophila (Lp). Previous work concluded that the stringent response and the sigma factor RpoS are essential for the survival of Lp in water. In the present study, we investigated the role of the LetA/S two-component signal transduction system in the successful survival of Lp in water. In addition to cell size reduction in the post-exponential phase, LetS also contributes to cell size reduction when Lp is exposed to water. Importantly, absence of the sensor kinase results in a significantly lower survival as measured by CFUs in water at various temperatures and an increased sensitivity to heat shock. According to the transcriptomic analysis, LetA/S orchestrates a general transcriptomic downshift of major metabolic pathways upon exposure to water leading to better culturability, and likely survival, suggesting a potential link with the stringent response. However, the expression of the LetA/S regulated small regulatory RNAs, RsmY and RsmZ, is not changed in a relAspoT mutant, which indicates that the stringent response and the LetA/S response are two distinct regulatory systems contributing to the survival of Lp in water.
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Affiliation(s)
- Nilmini Mendis
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, Quebec, Canada
| | - Peter McBride
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, Quebec, Canada
| | - Joseph Saoud
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, Quebec, Canada
| | - Thangadurai Mani
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, Quebec, Canada
| | - Sebastien P Faucher
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, Quebec, Canada.
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Schmölders J, Manske C, Otto A, Hoffmann C, Steiner B, Welin A, Becher D, Hilbi H. Comparative Proteomics of Purified Pathogen Vacuoles Correlates Intracellular Replication of Legionella pneumophila with the Small GTPase Ras-related protein 1 (Rap1). Mol Cell Proteomics 2017; 16:622-641. [PMID: 28183814 DOI: 10.1074/mcp.m116.063453] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 01/24/2017] [Indexed: 12/19/2022] Open
Abstract
Legionella pneumophila is an opportunistic bacterial pathogen that causes a severe lung infection termed "Legionnaires' disease." The pathogen replicates in environmental protozoa as well as in macrophages within a unique membrane-bound compartment, the Legionella-containing-vacuole (LCV). LCV formation requires the bacterial Icm/Dot type IV secretion system, which translocates ca. 300 "effector proteins" into host cells, where they target distinct host factors. The L. pneumophila "pentuple" mutant (Δpentuple) lacks 5 gene clusters (31% of the effector proteins) and replicates in macrophages but not in Dictyostelium discoideum amoeba. To elucidate the host factors defining a replication-permissive compartment, we compare here the proteomes of intact LCVs isolated from D. discoideum or macrophages infected with Δpentuple or the parental strain Lp02. This analysis revealed that the majority of host proteins are shared in D. discoideum or macrophage LCVs containing the mutant or the parental strain, respectively, whereas some proteins preferentially localize to distinct LCVs. The small GTPase Rap1 was identified on D. discoideum LCVs containing strain Lp02 but not the Δpentuple mutant and on macrophage LCVs containing either strain. The localization pattern of active Rap1 on D. discoideum or macrophage LCVs was confirmed by fluorescence microscopy and imaging flow cytometry, and the depletion of Rap1 by RNA interference significantly reduced the intracellular growth of L. pneumophila Thus, comparative proteomics identified Rap1 as a novel LCV host component implicated in intracellular replication of L. pneumophila.
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Affiliation(s)
- Johanna Schmölders
- From the ‡Max von Pettenkofer Institute, Ludwig-Maximilians University, Munich, Germany
| | - Christian Manske
- From the ‡Max von Pettenkofer Institute, Ludwig-Maximilians University, Munich, Germany
| | - Andreas Otto
- §Institute for Microbiology, Ernst Moritz Arndt University, Greifswald, Germany
| | - Christine Hoffmann
- From the ‡Max von Pettenkofer Institute, Ludwig-Maximilians University, Munich, Germany
| | - Bernhard Steiner
- ¶Institute of Medical Microbiology, University of Zürich, Switzerland
| | - Amanda Welin
- ¶Institute of Medical Microbiology, University of Zürich, Switzerland
| | - Dörte Becher
- §Institute for Microbiology, Ernst Moritz Arndt University, Greifswald, Germany;
| | - Hubert Hilbi
- From the ‡Max von Pettenkofer Institute, Ludwig-Maximilians University, Munich, Germany; .,¶Institute of Medical Microbiology, University of Zürich, Switzerland
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Differential Proteome Between Patient-Related and Non-related Environmental Isolates of Legionella pneumophila. Curr Microbiol 2017; 74:344-355. [PMID: 28138785 DOI: 10.1007/s00284-017-1198-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 01/11/2017] [Indexed: 10/20/2022]
Abstract
Molecular epidemiologic studies of Legionella have shown different molecular types coexisting in the same environment, with only one having the ability to trigger an outbreak. We therefore studied the proteome of isolates of these different molecular types in search of the proteins responsible for infection. In this study, we performed a differential proteomic analysis between patient-related and non-patient-related environmental isolates using two-dimensional difference gel electrophoresis (2D-DIGE) combined with mass spectrometry. Sixty-three spots were observed as being different between the two groups; 31 spots were identified corresponding to 23 different proteins. Patient-related isolates overexpressed proteins associated with metabolism, with enzymes of the tricarboxylic acid cycle and the degradation pathways being the most abundant proteins identified. However, the largest group of non-patient-related proteins was associated with stress response. Furthermore, the MOMP protein was located in different spots depending on their patient-related or non-patient-related origin, suggesting different post-translational modifications. According to these results, different bacterial adaptation pathways are activated in stress conditions which influence their ability to produce infection.
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Beyrakhova KA, van Straaten K, Li L, Boniecki MT, Anderson DH, Cygler M. Structural and Functional Investigations of the Effector Protein LpiR1 from Legionella pneumophila. J Biol Chem 2016; 291:15767-77. [PMID: 27226543 DOI: 10.1074/jbc.m115.708701] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Indexed: 01/14/2023] Open
Abstract
Legionella pneumophila is a causative agent of a severe pneumonia, known as Legionnaires' disease. Legionella pathogenicity is mediated by specific virulence factors, called bacterial effectors, which are injected into the invaded host cell by the bacterial type IV secretion system. Bacterial effectors are involved in complex interactions with the components of the host cell immune and signaling pathways, which eventually lead to bacterial survival and replication inside the mammalian cell. Structural and functional studies of bacterial effectors are, therefore, crucial for elucidating the mechanisms of Legionella virulence. Here we describe the crystal structure of the LpiR1 (Lpg0634) effector protein and investigate the effects of its overexpression in mammalian cells. LpiR1 is an α-helical protein that consists of two similar domains aligned in an antiparallel fashion. The hydrophilic cleft between the domains might serve as a binding site for a potential host cell interaction partner. LpiR1 binds the phosphate group at a conserved site and is stabilized by Mn(2+), Ca(2+), or Mg(2+) ions. When overexpressed in mammalian cells, a GFP-LpiR1 fusion protein is localized in the cytoplasm. Intracellular signaling antibody array analysis revealed small changes in the phosphorylation state of several components of the Akt signaling pathway in HEK293T cells overexpressing LpiR1.
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Affiliation(s)
| | | | - Lei Li
- From the Department of Biochemistry and
| | | | - Deborah H Anderson
- Cancer Research, Saskatchewan Cancer Agency, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada
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Gillmaier N, Schunder E, Kutzner E, Tlapák H, Rydzewski K, Herrmann V, Stämmler M, Lasch P, Eisenreich W, Heuner K. Growth-related Metabolism of the Carbon Storage Poly-3-hydroxybutyrate in Legionella pneumophila. J Biol Chem 2016; 291:6471-82. [PMID: 26792862 DOI: 10.1074/jbc.m115.693481] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Indexed: 11/06/2022] Open
Abstract
Legionella pneumophila, the causative agent of Legionnaires disease, has a biphasic life cycle with a switch from a replicative to a transmissive phenotype. During the replicative phase, the bacteria grow within host cells in Legionella-containing vacuoles. During the transmissive phenotype and the postexponential (PE) growth phase, the pathogens express virulence factors, become flagellated, and leave the Legionella-containing vacuoles. Using (13)C labeling experiments, we now show that, under in vitro conditions, serine is mainly metabolized during the replicative phase for the biosynthesis of some amino acids and for energy generation. During the PE phase, these carbon fluxes are reduced, and glucose also serves as an additional carbon substrate to feed the biosynthesis of poly-3-hydroxybuyrate (PHB), an essential carbon source for transmissive L. pneumophila. Whole-cell FTIR analysis and comparative isotopologue profiling further reveal that a putative 3-ketothiolase (Lpp1788) and a PHB polymerase (Lpp0650), but not enzymes of the crotonyl-CoA pathway (Lpp0931-0933) are involved in PHB metabolism during the PE phase. However, the data also reflect that additional bypassing reactions for PHB synthesis exist in agreement with in vivo competition assays using Acanthamoeba castellannii or human macrophage-like U937 cells as host cells. The data suggest that substrate usage and PHB metabolism are coordinated during the life cycle of the pathogen.
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Affiliation(s)
- Nadine Gillmaier
- From the Lehrstuhl für Biochemie, Technische Universität München, Lichtenbergstrasse 4, 85747 Garching, Germany
| | - Eva Schunder
- Working group "Cellular Interactions of Bacterial Pathogens," ZBS 2, Robert Koch-Institute, Seestrasse 10, 13353 Berlin, Germany, and
| | - Erika Kutzner
- From the Lehrstuhl für Biochemie, Technische Universität München, Lichtenbergstrasse 4, 85747 Garching, Germany
| | - Hana Tlapák
- Working group "Cellular Interactions of Bacterial Pathogens," ZBS 2, Robert Koch-Institute, Seestrasse 10, 13353 Berlin, Germany, and
| | - Kerstin Rydzewski
- Working group "Cellular Interactions of Bacterial Pathogens," ZBS 2, Robert Koch-Institute, Seestrasse 10, 13353 Berlin, Germany, and
| | - Vroni Herrmann
- Working group "Cellular Interactions of Bacterial Pathogens," ZBS 2, Robert Koch-Institute, Seestrasse 10, 13353 Berlin, Germany, and
| | - Maren Stämmler
- ZBS 6 "Proteomics and Spectroscopy," Robert Koch-Institute, Nordufer 20, 13353 Berlin, Germany
| | - Peter Lasch
- ZBS 6 "Proteomics and Spectroscopy," Robert Koch-Institute, Nordufer 20, 13353 Berlin, Germany
| | - Wolfgang Eisenreich
- From the Lehrstuhl für Biochemie, Technische Universität München, Lichtenbergstrasse 4, 85747 Garching, Germany,
| | - Klaus Heuner
- Working group "Cellular Interactions of Bacterial Pathogens," ZBS 2, Robert Koch-Institute, Seestrasse 10, 13353 Berlin, Germany, and
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8
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Aurass P, Gerlach T, Becher D, Voigt B, Karste S, Bernhardt J, Riedel K, Hecker M, Flieger A. Life Stage-specific Proteomes of Legionella pneumophila Reveal a Highly Differential Abundance of Virulence-associated Dot/Icm effectors. Mol Cell Proteomics 2015; 15:177-200. [PMID: 26545400 DOI: 10.1074/mcp.m115.053579] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Indexed: 12/28/2022] Open
Abstract
Major differences in the transcriptional program underlying the phenotypic switch between exponential and post-exponential growth of Legionella pneumophila were formerly described characterizing important alterations in infection capacity. Additionally, a third state is known where the bacteria transform in a viable but nonculturable state under stress, such as starvation. We here describe phase-related proteomic changes in exponential phase (E), postexponential phase (PE) bacteria, and unculturable microcosms (UNC) containing viable but nonculturable state cells, and identify phase-specific proteins. We present data on different bacterial subproteomes of E and PE, such as soluble whole cell proteins, outer membrane-associated proteins, and extracellular proteins. In total, 1368 different proteins were identified, 922 were quantified and 397 showed differential abundance in E/PE. The quantified subproteomes of soluble whole cell proteins, outer membrane-associated proteins, and extracellular proteins; 841, 55, and 77 proteins, respectively, were visualized in Voronoi treemaps. 95 proteins were quantified exclusively in E, such as cell division proteins MreC, FtsN, FtsA, and ZipA; 33 exclusively in PE, such as motility-related proteins of flagellum biogenesis FlgE, FlgK, and FliA; and 9 exclusively in unculturable microcosms soluble whole cell proteins, such as hypothetical, as well as transport/binding-, and metabolism-related proteins. A high frequency of differentially abundant or phase-exclusive proteins was observed among the 91 quantified effectors of the major virulence-associated protein secretion system Dot/Icm (> 60%). 24 were E-exclusive, such as LepA/B, YlfA, MavG, Lpg2271, and 13 were PE-exclusive, such as RalF, VipD, Lem10. The growth phase-related specific abundance of a subset of Dot/Icm virulence effectors was confirmed by means of Western blotting. We therefore conclude that many effectors are predominantly abundant at either E or PE which suggests their phase specific function. The distinct temporal or spatial presence of such proteins might have important implications for functional assignments in the future or for use as life-stage specific markers for pathogen analysis.
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Affiliation(s)
- Philipp Aurass
- From the ‡Robert Koch-Institut, Wernigerode Branch, Division of Enteropathogenic Bacteria and Legionella (FG11), Burgstr. 37, 38855 Wernigerode, Germany
| | - Thomas Gerlach
- From the ‡Robert Koch-Institut, Wernigerode Branch, Division of Enteropathogenic Bacteria and Legionella (FG11), Burgstr. 37, 38855 Wernigerode, Germany
| | - Dörte Becher
- §Institute for Microbiology, Ernst-Moritz-Arndt University Greifswald, Friedrich-Ludwig-Jahn-Str. 15, 17487 Greifswald, Germany
| | - Birgit Voigt
- §Institute for Microbiology, Ernst-Moritz-Arndt University Greifswald, Friedrich-Ludwig-Jahn-Str. 15, 17487 Greifswald, Germany
| | - Susanne Karste
- From the ‡Robert Koch-Institut, Wernigerode Branch, Division of Enteropathogenic Bacteria and Legionella (FG11), Burgstr. 37, 38855 Wernigerode, Germany
| | - Jörg Bernhardt
- §Institute for Microbiology, Ernst-Moritz-Arndt University Greifswald, Friedrich-Ludwig-Jahn-Str. 15, 17487 Greifswald, Germany
| | - Katharina Riedel
- §Institute for Microbiology, Ernst-Moritz-Arndt University Greifswald, Friedrich-Ludwig-Jahn-Str. 15, 17487 Greifswald, Germany
| | - Michael Hecker
- §Institute for Microbiology, Ernst-Moritz-Arndt University Greifswald, Friedrich-Ludwig-Jahn-Str. 15, 17487 Greifswald, Germany
| | - Antje Flieger
- From the ‡Robert Koch-Institut, Wernigerode Branch, Division of Enteropathogenic Bacteria and Legionella (FG11), Burgstr. 37, 38855 Wernigerode, Germany;
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Quero S, Párraga-Niño N, García-Núñez M, Sabrià M. [Proteomics in infectious diseases]. Enferm Infecc Microbiol Clin 2015; 34:253-60. [PMID: 25583331 DOI: 10.1016/j.eimc.2014.07.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Revised: 07/22/2014] [Accepted: 07/30/2014] [Indexed: 11/27/2022]
Abstract
Infectious diseases have a high incidence in the population, causing a major impact on global health. In vitro culture of microorganisms is the first technique applied for infection diagnosis which is laborious and time consuming. In recent decades, efforts have been focused on the applicability of "Omics" sciences, highlighting the progress provided by proteomic techniques in the field of infectious diseases. This review describes the management, processing and analysis of biological samples for proteomic research.
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Affiliation(s)
- Sara Quero
- Unitat de Malalties Infeccioses, Fundació Institut d'Investigació Germans Trias i Pujol, Badalona, Barcelona, España; Universitat Autònoma de Barcelona, Cerdanyola, Barcelona, España
| | - Noemí Párraga-Niño
- Unitat de Malalties Infeccioses, Fundació Institut d'Investigació Germans Trias i Pujol, Badalona, Barcelona, España.
| | - Marian García-Núñez
- Unitat de Malalties Infeccioses, Fundació Institut d'Investigació Germans Trias i Pujol, Badalona, Barcelona, España; CIBER de Enfermedades Respiratorias, Bunyola, Illes Balears, España
| | - Miquel Sabrià
- Universitat Autònoma de Barcelona, Cerdanyola, Barcelona, España; CIBER de Enfermedades Respiratorias, Bunyola, Illes Balears, España; Unitat de Malalties Infeccioses, Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona, España
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10
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Scaturro M, Barello C, Giusti MD, Fontana S, Pinci F, Giuffrida MG, Ricci ML. Identification and characterization of genes, encoding the 3-hydroxybutyrate dehydrogenase and a putative lipase, in an avirulent spontaneousLegionella pneumophilaserogroup 6 mutant. APMIS 2014; 123:330-41. [DOI: 10.1111/apm.12349] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 10/22/2014] [Indexed: 12/23/2022]
Affiliation(s)
- Maria Scaturro
- Department of Infectious Parasitic Immune-mediated Diseases; Istituto Superiore di Sanità; Rome Italy
| | - Cristina Barello
- Istituto di Scienze delle Produzioni Alimentari; CNR; Sezione di Torino; Colleretto Giacosa (TO) Italy
| | - Melania De Giusti
- Department of Infectious Parasitic Immune-mediated Diseases; Istituto Superiore di Sanità; Rome Italy
| | - Stefano Fontana
- Department of Infectious Parasitic Immune-mediated Diseases; Istituto Superiore di Sanità; Rome Italy
| | - Federica Pinci
- Department of Infectious Parasitic Immune-mediated Diseases; Istituto Superiore di Sanità; Rome Italy
| | - Maria Gabriella Giuffrida
- Istituto di Scienze delle Produzioni Alimentari; CNR; Sezione di Torino; Colleretto Giacosa (TO) Italy
| | - Maria Luisa Ricci
- Department of Infectious Parasitic Immune-mediated Diseases; Istituto Superiore di Sanità; Rome Italy
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11
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Ortega AD, Quereda JJ, Pucciarelli MG, García-del Portillo F. Non-coding RNA regulation in pathogenic bacteria located inside eukaryotic cells. Front Cell Infect Microbiol 2014; 4:162. [PMID: 25429360 PMCID: PMC4228915 DOI: 10.3389/fcimb.2014.00162] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Accepted: 10/20/2014] [Indexed: 01/06/2023] Open
Abstract
Intracellular bacterial pathogens have evolved distinct lifestyles inside eukaryotic cells. Some pathogens coexist with the infected cell in an obligate intracellular state, whereas others transit between the extracellular and intracellular environment. Adaptation to these intracellular lifestyles is regulated in both space and time. Non-coding small RNAs (sRNAs) are post-transcriptional regulatory molecules that fine-tune important processes in bacterial physiology including cell envelope architecture, intermediate metabolism, bacterial communication, biofilm formation, and virulence. Recent studies have shown production of defined sRNA species by intracellular bacteria located inside eukaryotic cells. The molecules targeted by these sRNAs and their expression dynamics along the intracellular infection cycle remain, however, poorly characterized. Technical difficulties linked to the isolation of “intact” intracellular bacteria from infected host cells might explain why sRNA regulation in these specialized pathogens is still a largely unexplored field. Transition from the extracellular to the intracellular lifestyle provides an ideal scenario in which regulatory sRNAs are intended to participate; so much work must be done in this direction. This review focuses on sRNAs expressed by intracellular bacterial pathogens during the infection of eukaryotic cells, strategies used with these pathogens to identify sRNAs required for virulence, and the experimental technical challenges associated to this type of studies. We also discuss varied techniques for their potential application to study RNA regulation in intracellular bacterial infections.
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Affiliation(s)
- Alvaro D Ortega
- Centro Nacional de Biotecnología - Consejo Superior de Investigaciones Científicas (CNB-CSIC) Madrid, Spain
| | - Juan J Quereda
- Centro Nacional de Biotecnología - Consejo Superior de Investigaciones Científicas (CNB-CSIC) Madrid, Spain
| | - M Graciela Pucciarelli
- Centro Nacional de Biotecnología - Consejo Superior de Investigaciones Científicas (CNB-CSIC) Madrid, Spain ; Departamento de Biología Molecular, Universidad Autónoma de Madrid, Centro de Biología Molecular 'Severo Ochoa' (CBMSO-CSIC) Madrid, Spain
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12
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Abdelhady H, Garduño RA. The progeny ofLegionella pneumophilain human macrophages shows unique developmental traits. FEMS Microbiol Lett 2013; 349:99-107. [DOI: 10.1111/1574-6968.12300] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 10/14/2013] [Indexed: 11/30/2022] Open
Affiliation(s)
- Hany Abdelhady
- Department of Microbiology and Immunology; Dalhousie University; Halifax NS Canada
| | - Rafael A. Garduño
- Department of Microbiology and Immunology; Dalhousie University; Halifax NS Canada
- Department of Medicine-Division of Infectious Diseases; Dalhousie University; Halifax NS Canada
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13
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Human lung tissue explants reveal novel interactions during Legionella pneumophila infections. Infect Immun 2013; 82:275-85. [PMID: 24166955 DOI: 10.1128/iai.00703-13] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Histological and clinical investigations describe late stages of Legionnaires' disease but cannot characterize early events of human infection. Cellular or rodent infection models lack the complexity of tissue or have nonhuman backgrounds. Therefore, we developed and applied a novel model for Legionella pneumophila infection comprising living human lung tissue. We stimulated lung explants with L. pneumophila strains and outer membrane vesicles (OMVs) to analyze tissue damage, bacterial replication, and localization as well as the transcriptional response of infected tissue. Interestingly, we found that extracellular adhesion of L. pneumophila to the entire alveolar lining precedes bacterial invasion and replication in recruited macrophages. In contrast, OMVs predominantly bound to alveolar macrophages. Specific damage to septa and epithelia increased over 48 h and was stronger in wild-type-infected and OMV-treated samples than in samples infected with the replication-deficient, type IVB secretion-deficient DotA(-) strain. Transcriptome analysis of lung tissue explants revealed a differential regulation of 2,499 genes after infection. The transcriptional response included the upregulation of uteroglobin and the downregulation of the macrophage receptor with collagenous structure (MARCO). Immunohistochemistry confirmed the downregulation of MARCO at sites of pathogen-induced tissue destruction. Neither host factor has ever been described in the context of L. pneumophila infections. This work demonstrates that the tissue explant model reproduces realistic features of Legionnaires' disease and reveals new functions for bacterial OMVs during infection. Our model allows us to characterize early steps of human infection which otherwise are not feasible for investigations.
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Growth media simulating ileal and colonic environments affect the intracellular proteome and carbon fluxes of enterohemorrhagic Escherichia coli O157:H7 strain EDL933. Appl Environ Microbiol 2013; 79:3703-15. [PMID: 23563955 DOI: 10.1128/aem.00062-13] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In this study, the intracellular proteome of Escherichia coli O157:H7 strain EDL933 was analyzed by two-dimensional gel electrophoresis and matrix-assisted laser desorption ionization-time-of-flight (MALDI-TOF) spectrometry after growth in simulated ileal environment media (SIEM) and simulated colonic environment media (SCEM) under aerobic and microaerobic conditions. Differentially expressed intracellular proteins were identified and allocated to functional protein groups. Moreover, metabolic fluxes were analyzed by isotopologue profiling with [U-(13)C(6)]glucose as a tracer. The results of this study show that EDL933 responds with differential expression of a complex network of proteins and metabolic pathways, reflecting the high metabolic adaptability of the strain. Growth in SIEM and SCEM is obviously facilitated by the upregulation of nucleotide biosynthesis pathway proteins and could be impaired by exposition to 50 µM 6-mercaptopurine under aerobic conditions. Notably, various stress and virulence factors, including Shiga toxin, were expressed without having contact with a human host.
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de Barsy M, Greub G. Functional genomics of intracellular bacteria. Brief Funct Genomics 2013; 12:341-53. [DOI: 10.1093/bfgp/elt012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Ge J, Shao F. Manipulation of host vesicular trafficking and innate immune defence by Legionella Dot/Icm effectors. Cell Microbiol 2011; 13:1870-80. [PMID: 21981078 DOI: 10.1111/j.1462-5822.2011.01710.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Legionella pneumophila, the causative agent of Legionnaires' disease, infects and replicates in macrophages and amoebas. Following internalization, L. pneumophila resides in a vacuole structure called Legionella-containing vacuole (LCV). The LCV escapes from the endocytic maturation process and avoids fusion with the lysosome, a hallmark of Legionella pathogenesis. Interference with the secretory vesicle transport and avoiding lysosomal targeting render the LCV permissive for L. pneumophila intracellular replication. Central to L. pneumophila pathogenesis is a defect in the organelle trafficking/intracellular multiplication (Dot/Icm) type IV secretion system that translocates a large number of effector proteins into host cells. Many of the Dot/Icm effectors employ diverse and sophisticated biochemical strategies to manipulate the host vesicular transport system, playing an important role in LCV biogenesis and trafficking. Similar to other bacterial pathogens, L. pneumophila also delivers effector proteins to modulate or counteract host innate immune defence pathways such as the NF-κB and apoptotic signalling. This review summarizes the known functions and mechanisms of Dot/Icm effectors that target host membrane trafficking and innate immune defence pathways.
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Affiliation(s)
- Jianning Ge
- National Institute of Biological Sciences, Zhongguancun Life Science Park, Beijing 102206, China
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