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Lehman SS, Verhoeve VI, Driscoll TP, Beckmann JF, Gillespie JJ. Metagenome diversity illuminates the origins of pathogen effectors. mBio 2024; 15:e0075923. [PMID: 38564675 PMCID: PMC11077975 DOI: 10.1128/mbio.00759-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 02/12/2024] [Indexed: 04/04/2024] Open
Abstract
Recent metagenome-assembled genome (MAG) analyses have profoundly impacted Rickettsiology systematics. The discovery of basal lineages (novel families Mitibacteraceae and Athabascaceae) with predicted extracellular lifestyles exposed an evolutionary timepoint for the transition to host dependency, which seemingly occurred independent of mitochondrial evolution. Notably, these basal rickettsiae carry the Rickettsiales vir homolog (rvh) type IV secretion system and purportedly use rvh to kill congener microbes rather than parasitize host cells as described for later-evolving rickettsial pathogens. MAG analysis also substantially increased diversity for the genus Rickettsia and delineated a sister lineage (the novel genus Tisiphia) that stands to inform on the emergence of human pathogens from protist and invertebrate endosymbionts. Herein, we probed Rickettsiales MAG and genomic diversity for the distribution of Rickettsia rvh effectors to ascertain their origins. A sparse distribution of most Rickettsia rvh effectors outside of Rickettsiaceae lineages illuminates unique rvh evolution from basal extracellular species and other rickettsial families. Remarkably, nearly every effector was found in multiple divergent forms with variable architectures, indicating profound roles for gene duplication and recombination in shaping effector repertoires in Rickettsia pathogens. Lateral gene transfer plays a prominent role in shaping the rvh effector landscape, as evinced by the discovery of many effectors on plasmids and conjugative transposons, as well as pervasive effector gene exchange between Rickettsia and Legionella species. Our study exemplifies how MAGs can yield insight into pathogen effector origins, particularly how effector architectures might become tailored to the discrete host cell functions of different eukaryotic hosts.IMPORTANCEWhile rickettsioses are deadly vector-borne human diseases, factors distinguishing Rickettsia pathogens from the innumerable bevy of environmental rickettsial endosymbionts remain lacking. Recent metagenome-assembled genome (MAG) studies revealed evolutionary timepoints for rickettsial transitions to host dependency. The rvh type IV secretion system was likely repurposed from congener killing in basal extracellular species to parasitizing host cells in later-evolving pathogens. Our analysis of MAG diversity for over two dozen rvh effectors unearthed their presence in some non-pathogens. However, most effectors were found in multiple divergent forms with variable architectures, indicating gene duplication and recombination-fashioned effector repertoires of Rickettsia pathogens. Lateral gene transfer substantially shaped pathogen effector arsenals, evinced by the discovery of effectors on plasmids and conjugative transposons, as well as pervasive effector gene exchanges between Rickettsia and Legionella species. Our study exemplifies how MAGs yield insight into pathogen effector origins and evolutionary processes tailoring effectors to eukaryotic host cell biology.
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Affiliation(s)
- Stephanie S. Lehman
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
| | - Victoria I. Verhoeve
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Timothy P. Driscoll
- Department of Biology, West Virginia University, Morgantown, West Virginia, USA
| | - John F. Beckmann
- Department of Microbiology and Immunology, University of South Alabama, Mobile, Alabama, USA
| | - Joseph J. Gillespie
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
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2
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Zelikman S, Dudkevich R, Korenfeld-Tzemach H, Shmidov E, Levi-Ferber M, Shoshani S, Ben-Aroya S, Henis-Korenblit S, Banin E. PemB, a type III secretion effector in Pseudomonas aeruginosa, affects Caenorhabditis elegans life span. Heliyon 2024; 10:e29751. [PMID: 38681583 PMCID: PMC11053225 DOI: 10.1016/j.heliyon.2024.e29751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 04/08/2024] [Accepted: 04/15/2024] [Indexed: 05/01/2024] Open
Abstract
Pseudomonas aeruginosa is one of the leading nosocomial opportunistic pathogens causing acute and chronic infections. Among its main virulent factors is the Type III secretion system (T3SS) which enhances disease severity by delivering effectors to the host in a highly regulated manner. Despite its importance for virulence, only six T3SS-dependent effectors have been discovered so far. Previously, we identified two new potential effectors using a machine-learning algorithm approach. Here we demonstrate that one of these effectors, PemB, is indeed virulent. Using a live Caenorhabditis elegans infection model, we demonstrate this effector damages the integrity of the intestine barrier leading to the death of the host. Implementing a high-throughput assay using Saccharomyces cerevisiae, we identified several candidate proteins that interact with PemB. One of them, EFT1, has an ortholog in C. elegans (eef-2) and is also an essential gene and a well-known target utilized by different pathogens to induce toxicity to the worm. Accordingly, we found that by silencing the eef-2 gene in C. elegans, PemB could no longer induce its toxic effect. The current study further uncovers the complex machinery assisting P. aeruginosa virulence and may provide novel insight how to manage infection associated with this hard-to-treat pathogen.
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Affiliation(s)
- Shira Zelikman
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Max and Anna Webb, 5290002, Ramat Gan, Israel
- The Institute for Nanotechnology and Advanced Materials, Bar-Ilan University, Max and Anna Webb, 5290002, Ramat Gan, Israel
| | - Reut Dudkevich
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Max and Anna Webb, 5290002, Ramat Gan, Israel
| | - Hadar Korenfeld-Tzemach
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Max and Anna Webb, 5290002, Ramat Gan, Israel
- The Institute for Nanotechnology and Advanced Materials, Bar-Ilan University, Max and Anna Webb, 5290002, Ramat Gan, Israel
| | - Esther Shmidov
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Max and Anna Webb, 5290002, Ramat Gan, Israel
- The Institute for Nanotechnology and Advanced Materials, Bar-Ilan University, Max and Anna Webb, 5290002, Ramat Gan, Israel
| | - Mor Levi-Ferber
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Max and Anna Webb, 5290002, Ramat Gan, Israel
| | - Sivan Shoshani
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Max and Anna Webb, 5290002, Ramat Gan, Israel
- The Institute for Nanotechnology and Advanced Materials, Bar-Ilan University, Max and Anna Webb, 5290002, Ramat Gan, Israel
| | - Shay Ben-Aroya
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Max and Anna Webb, 5290002, Ramat Gan, Israel
- The Institute for Nanotechnology and Advanced Materials, Bar-Ilan University, Max and Anna Webb, 5290002, Ramat Gan, Israel
| | - Sivan Henis-Korenblit
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Max and Anna Webb, 5290002, Ramat Gan, Israel
| | - Ehud Banin
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Max and Anna Webb, 5290002, Ramat Gan, Israel
- The Institute for Nanotechnology and Advanced Materials, Bar-Ilan University, Max and Anna Webb, 5290002, Ramat Gan, Israel
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3
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Verhoeve VI, Lehman SS, Driscoll TP, Beckmann JF, Gillespie JJ. Metagenome diversity illuminates origins of pathogen effectors. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.26.530123. [PMID: 36909625 PMCID: PMC10002696 DOI: 10.1101/2023.02.26.530123] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
Recent metagenome assembled genome (MAG) analyses have profoundly impacted Rickettsiology systematics. Discovery of basal lineages (Mitibacteraceae and Athabascaceae) with predicted extracellular lifestyles reveals an evolutionary timepoint for the transition to host dependency, which occurred independent of mitochondrial evolution. Notably, these basal rickettsiae carry the Rickettsiales vir homolog (rvh) type IV secretion system (T4SS) and purportedly use rvh to kill congener microbes rather than parasitize host cells as described for derived rickettsial pathogens. MAG analysis also substantially increased diversity for genus Rickettsia and delineated a basal lineage (Tisiphia) that stands to inform on the rise of human pathogens from protist and invertebrate endosymbionts. Herein, we probed Rickettsiales MAG and genomic diversity for the distribution of Rickettsia rvh effectors to ascertain their origins. A sparse distribution of most Rickettsia rvh effectors outside of Rickettsiaceae lineages indicates unique rvh evolution from basal extracellular species and other rickettsial families. Remarkably, nearly every effector was found in multiple divergent forms with variable architectures, illuminating profound roles for gene duplication and recombination in shaping effector repertoires in Rickettsia pathogens. Lateral gene transfer plays a prominent role shaping the rvh effector landscape, as evinced by the discover of many effectors on plasmids and conjugative transposons, as well as pervasive effector gene exchange between Rickettsia and Legionella species. Our study exemplifies how MAGs can provide incredible insight on the origins of pathogen effectors and how their architectural modifications become tailored to eukaryotic host cell biology.
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Affiliation(s)
- Victoria I Verhoeve
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Stephanie S Lehman
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Timothy P Driscoll
- Department of Biology, West Virginia University, Morgantown, West Virginia, USA
| | - John F Beckmann
- Microbiology and Immunology, University of South Alabama, Mobile, AL, USA
| | - Joseph J Gillespie
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
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4
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Lê-Bury P, Druart K, Savin C, Lechat P, Mas Fiol G, Matondo M, Bécavin C, Dussurget O, Pizarro-Cerdá J. Yersiniomics, a Multi-Omics Interactive Database for Yersinia Species. Microbiol Spectr 2023; 11:e0382622. [PMID: 36847572 PMCID: PMC10100798 DOI: 10.1128/spectrum.03826-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 01/26/2023] [Indexed: 03/01/2023] Open
Abstract
The genus Yersinia includes a large variety of nonpathogenic and life-threatening pathogenic bacteria, which cause a broad spectrum of diseases in humans and animals, such as plague, enteritis, Far East scarlet-like fever (FESLF), and enteric redmouth disease. Like most clinically relevant microorganisms, Yersinia spp. are currently subjected to intense multi-omics investigations whose numbers have increased extensively in recent years, generating massive amounts of data useful for diagnostic and therapeutic developments. The lack of a simple and centralized way to exploit these data led us to design Yersiniomics, a web-based platform allowing straightforward analysis of Yersinia omics data. Yersiniomics contains a curated multi-omics database at its core, gathering 200 genomic, 317 transcriptomic, and 62 proteomic data sets for Yersinia species. It integrates genomic, transcriptomic, and proteomic browsers, a genome viewer, and a heatmap viewer to navigate within genomes and experimental conditions. For streamlined access to structural and functional properties, it directly links each gene to GenBank, the Kyoto Encyclopedia of Genes and Genomes (KEGG), UniProt, InterPro, IntAct, and the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) and each experiment to Gene Expression Omnibus (GEO), the European Nucleotide Archive (ENA), or the Proteomics Identifications Database (PRIDE). Yersiniomics provides a powerful tool for microbiologists to assist with investigations ranging from specific gene studies to systems biology studies. IMPORTANCE The expanding genus Yersinia is composed of multiple nonpathogenic species and a few pathogenic species, including the deadly etiologic agent of plague, Yersinia pestis. In 2 decades, the number of genomic, transcriptomic, and proteomic studies on Yersinia grew massively, delivering a wealth of data. We developed Yersiniomics, an interactive web-based platform, to centralize and analyze omics data sets on Yersinia species. The platform allows user-friendly navigation between genomic data, expression data, and experimental conditions. Yersiniomics will be a valuable tool to microbiologists.
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Affiliation(s)
- Pierre Lê-Bury
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Yersinia Research Unit, Paris, France
| | - Karen Druart
- Institut Pasteur, Université Paris Cité, CNRS USR2000, Mass Spectrometry for Biology Unit, Proteomic Platform, Paris, France
| | - Cyril Savin
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Yersinia Research Unit, Paris, France
- Institut Pasteur, Université Paris Cité, Yersinia National Reference Laboratory, WHO Collaborating Research & Reference Centre for Plague FRA-140, Paris, France
| | - Pierre Lechat
- Institut Pasteur, Université Paris Cité, ALPS, Bioinformatic Hub, Paris, France
| | - Guillem Mas Fiol
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Yersinia Research Unit, Paris, France
| | - Mariette Matondo
- Institut Pasteur, Université Paris Cité, CNRS USR2000, Mass Spectrometry for Biology Unit, Proteomic Platform, Paris, France
| | | | - Olivier Dussurget
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Yersinia Research Unit, Paris, France
| | - Javier Pizarro-Cerdá
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Yersinia Research Unit, Paris, France
- Institut Pasteur, Université Paris Cité, Yersinia National Reference Laboratory, WHO Collaborating Research & Reference Centre for Plague FRA-140, Paris, France
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5
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Pereira CER, Resende TP, Daniel AGDS, Vannucci FA, Gebhart C, Guedes RMC. Evaluation of the role of clathrin and bacterial viability in the endocytosis of Lawsonia intracellularis. Front Vet Sci 2023; 10:1005676. [PMID: 36793380 PMCID: PMC9923121 DOI: 10.3389/fvets.2023.1005676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Accepted: 01/10/2023] [Indexed: 01/31/2023] Open
Abstract
Lawsonia intracellularis is an obligate intracellular bacterium and causative agent of proliferative enteropathy. The pathogenesis of L. intracellularis is not completely understood, including the endocytic mechanisms to access the host cell cytoplasm. In this study, we evaluated the mechanisms involved in endocytosis of L. intracellularis in vitro using intestinal porcine epithelial cells (IPEC-J2). Confocal microscopy was used to co-localize L. intracellularis and clathrin. Clathrin gene knockdown was then applied to verify whether L. intracellularis endocytosis is clathrin-dependent. Finally, internalization of viable and non-viable (bacteria were inactivated by heat) L. intracellularis organisms were assessed to study the role of the host cell during bacterial endocytosis. L. intracellularis organisms were observed co-localized with clathrin by confocal microscopy but the amount of L. intracellularis internalized in cells, with and without clathrin knockdown, did not differ statistically. The internalization of non-viable L. intracellularis showed a decrease in the internalization in cells with less clathrin synthesis (P<0.05). The present study is the first to elucidate the involvement of clathrin in the endocytosis of L. intracellularis. Clathrin-mediated endocytosis was shown to be an important, but not required, process for L. intracellularis internalization in porcine intestinal epithelial cells. Independence of bacterial viability for host cell internalization was also confirmed.
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Affiliation(s)
- Carlos Eduardo Real Pereira
- Department of Clinic and Surgery, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil,Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, MN, United States
| | - Talita Pilar Resende
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, MN, United States
| | - Amanda Gabrielle de Souza Daniel
- Department of Clinic and Surgery, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil,Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, MN, United States
| | - Fabio Augusto Vannucci
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, MN, United States
| | - Connie Gebhart
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, MN, United States
| | - Roberto Mauricio Carvalho Guedes
- Department of Clinic and Surgery, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil,*Correspondence: Roberto Mauricio Carvalho Guedes ✉
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6
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Jeschke A. An In Vitro System to Analyze Generation and Degradation of Phagosomal Phosphatidylinositol Phosphates. Methods Mol Biol 2023; 2692:261-274. [PMID: 37365474 DOI: 10.1007/978-1-0716-3338-0_18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/28/2023]
Abstract
Phagosomes are formed when phagocytic cells take up large particles, and they develop into phagolysosomes where the particles are degraded. The transformation of nascent phagosomes into phagolysosomes is a complex multi-step process, and the precise timing of these steps depends at least in part on phosphatidylinositol phosphates (PIPs). Some such-called "intracellular pathogens" are not delivered to microbicidal phagolysosomes and manipulate the PIP composition of the phagosomes they reside in. Studying the dynamic changes of the PIP composition of inert-particle phagosomes will help to understand why the pathogens' manipulations reprogram phagosome maturation.We here describe a method to detect and to follow generation and degradation of PIPs on purified phagosomes. To this end, phagosomes formed around inert latex beads are purified from J774E macrophages and incubated in vitro with PIP-binding protein domains or PIP-binding antibodies. Binding of such PIP sensors to phagosomes indicates presence of the cognate PIP and is quantified by immunofluorescence microscopy. When phagosomes are incubated with PIP sensors and ATP at a physiological temperature, the generation and degradation of PIPs can be followed, and PIP-metabolizing enzymes can be identified using specific inhibitory agents.
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Affiliation(s)
- Andreas Jeschke
- Institute for Cell Biology, University of Bonn, Bonn, Germany.
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7
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InvL, an Invasin-Like Adhesin, Is a Type II Secretion System Substrate Required for Acinetobacter baumannii Uropathogenesis. mBio 2022; 13:e0025822. [PMID: 35638734 PMCID: PMC9245377 DOI: 10.1128/mbio.00258-22] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Acinetobacter baumannii is an opportunistic pathogen of growing concern, as isolates are commonly multidrug resistant. While A. baumannii is most frequently associated with pulmonary infections, a significant proportion of clinical isolates come from urinary sources, highlighting its uropathogenic potential. The type II secretion system (T2SS) of commonly used model Acinetobacter strains is important for virulence in various animal models, but the potential role of the T2SS in urinary tract infection (UTI) remains unknown. Here, we used a catheter-associated UTI (CAUTI) model to demonstrate that a modern urinary isolate, UPAB1, requires the T2SS for full virulence. A proteomic screen to identify putative UPAB1 T2SS effectors revealed an uncharacterized lipoprotein with structural similarity to the intimin-invasin family, which serve as type V secretion system (T5SS) adhesins required for the pathogenesis of several bacteria. This protein, designated InvL, lacked the β-barrel domain associated with T5SSs but was confirmed to require the T2SS for both surface localization and secretion. This makes InvL the first identified T2SS effector belonging to the intimin-invasin family. InvL was confirmed to be an adhesin, as the protein bound to extracellular matrix components and mediated adhesion to urinary tract cell lines in vitro. Additionally, the invL mutant was attenuated in the CAUTI model, indicating a role in Acinetobacter uropathogenesis. Finally, bioinformatic analyses revealed that InvL is present in nearly all clinical isolates belonging to international clone 2, a lineage of significant clinical importance. In all, we conclude that the T2SS substrate InvL is an adhesin required for A. baumannii uropathogenesis. IMPORTANCE While pathogenic Acinetobacter can cause various infections, we recently found that 20% of clinical isolates come from urinary sources. Despite the clinical relevance of Acinetobacter as a uropathogen, few virulence factors involved in urinary tract colonization have been defined. Here, we identify a novel type II secretion system effector, InvL, which is required for full uropathogenesis by a modern urinary isolate. Although InvL has predicted structural similarity to the intimin-invasin family of autotransporter adhesins, InvL is predicted to be anchored to the membrane as a lipoprotein. Similar to other invasin homologs, however, we demonstrate that InvL is a bona fide adhesin capable of binding extracellular matrix components and mediating adhesion to urinary tract cell lines. In all, this work establishes InvL as an adhesin important for Acinetobacter's urinary tract virulence and represents the first report of a type II secretion system effector belonging to the intimin-invasin family.
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de Azevedo-Martins AC, Ocaña K, de Souza W, de Vasconcelos ATR, Teixeira MMG, Camargo EP, Alves JMP, Motta MCM. The Importance of Glycerophospholipid Production to the Mutualist Symbiosis of Trypanosomatids. Pathogens 2021; 11:pathogens11010041. [PMID: 35055989 PMCID: PMC8779180 DOI: 10.3390/pathogens11010041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Revised: 12/23/2021] [Accepted: 12/28/2021] [Indexed: 12/12/2022] Open
Abstract
The symbiosis in trypanosomatids is a mutualistic relationship characterized by extensive metabolic exchanges between the bacterium and the protozoan. The symbiotic bacterium can complete host essential metabolic pathways, such as those for heme, amino acid, and vitamin production. Experimental assays indicate that the symbiont acquires phospholipids from the host trypanosomatid, especially phosphatidylcholine, which is often present in bacteria that have a close association with eukaryotic cells. In this work, an in-silico study was performed to find genes involved in the glycerophospholipid (GPL) production of Symbiont Harboring Trypanosomatids (SHTs) and their respective bacteria, also extending the search for trypanosomatids that naturally do not have symbionts. Results showed that most genes for GPL synthesis are only present in the SHT. The bacterium has an exclusive sequence related to phosphatidylglycerol production and contains genes for phosphatidic acid production, which may enhance SHT phosphatidic acid production. Phylogenetic data did not indicate gene transfers from the bacterium to the SHT nucleus, proposing that enzymes participating in GPL route have eukaryotic characteristics. Taken together, our data indicate that, differently from other metabolic pathways described so far, the symbiont contributes little to the production of GPLs and acquires most of these molecules from the SHT.
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Affiliation(s)
- Allan C. de Azevedo-Martins
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro 20000-000, RJ, Brazil; (A.C.d.A.-M.); (W.d.S.)
| | - Kary Ocaña
- Laboratório Nacional de Computação Científica, Petropolis 25600-000, RJ, Brazil; (K.O.); (A.T.R.d.V.)
| | - Wanderley de Souza
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro 20000-000, RJ, Brazil; (A.C.d.A.-M.); (W.d.S.)
- Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagens, Rio de Janeiro 20000-000, RJ, Brazil
| | | | - Marta M. G. Teixeira
- Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Sao Paulo 05508-000, SP, Brazil; (M.M.G.T.); (E.P.C.)
| | - Erney P. Camargo
- Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Sao Paulo 05508-000, SP, Brazil; (M.M.G.T.); (E.P.C.)
| | - João M. P. Alves
- Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Sao Paulo 05508-000, SP, Brazil; (M.M.G.T.); (E.P.C.)
- Correspondence: (J.M.P.A.); (M.C.M.M.)
| | - Maria Cristina M. Motta
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro 20000-000, RJ, Brazil; (A.C.d.A.-M.); (W.d.S.)
- Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagens, Rio de Janeiro 20000-000, RJ, Brazil
- Correspondence: (J.M.P.A.); (M.C.M.M.)
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9
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Schlesier T, Siegmund A, Rescher U, Heilmann C. Characterization of the Atl-mediated staphylococcal internalization mechanism. Int J Med Microbiol 2020; 310:151463. [PMID: 33197865 DOI: 10.1016/j.ijmm.2020.151463] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 09/16/2020] [Accepted: 10/22/2020] [Indexed: 12/18/2022] Open
Abstract
Staphylococcus aureus internalization by non-professional phagocytes is considered a main pathogenicity mechanism leading to chronic infections. The well-established mechanism of Staphylococcus aureus internalization is mediated by fibronectin (Fn)-binding proteins (FnBPs), Fn as a bridging molecule and the host cell α5β1 integrin. We previously identified a novel alternative internalization mechanism in Staphylococcus aureus, which involves the major autolysin Atl and the host cell heat shock cognate protein 70 (Hsc70). Atl-dependent internalization is also employed by the coagulase-negative Staphylococcus epidermidis, where it might represent the major or even sole internalization mechanism, because of the lack of FnBP-homologous proteins. In this study, we aimed to further characterize the Atl-dependent staphylococcal internalization mechanism. We performed biomolecular interaction analysis (BIA) to quantify the adhesive properties of Atl and found multivalent and high affinity interactions of Atl with Fn and Hsc70. Confocal laser scanning microscopy (CLSM) and a flow-cytometric internalization assay in combination with different pharmacological inhibitors suggested an involvement of the α5β1 integrin, Fn and Hsc70 and subsequent signaling events mediated by Src and phosphoinositide 3 (PI3) kinases in the Atl-dependent staphylococcal uptake by EA.hy 926 cells. Further characterization of the endocytic machinery implicated a role for clathrin-dependent receptor-mediated endocytosis involving actin cytoskeletal rearrangements and microtubules. In conclusion, Atl ubiquitous among staphylococcal species may substitute for the FnBPs ensuring low-level internalization via a mechanism that seems to share important features with the FnBP-mediated staphylococcal uptake potentially being the prerequisite for the development of therapy-resistant chronic infections by staphylococcal strains that lack FnBPs.
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Affiliation(s)
- Tim Schlesier
- Institute of Medical Microbiology, D-48149, Münster, Germany
| | - Anke Siegmund
- Institute of Medical Microbiology, University Hospital of Jena, D-07747, Jena, Germany
| | - Ursula Rescher
- Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation (ZMBE), D-48149, Münster, Germany; Interdisciplinary Center for Clinical Research (IZKF), University Hospital of Münster, D-48149, Münster, Germany
| | - Christine Heilmann
- Institute of Medical Microbiology, D-48149, Münster, Germany; Interdisciplinary Center for Clinical Research (IZKF), University Hospital of Münster, D-48149, Münster, Germany.
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10
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Pessione E. The Russian Doll Model: How Bacteria Shape Successful and Sustainable Inter-Kingdom Relationships. Front Microbiol 2020; 11:573759. [PMID: 33193180 PMCID: PMC7606975 DOI: 10.3389/fmicb.2020.573759] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 08/31/2020] [Indexed: 12/20/2022] Open
Abstract
Successful inter-kingdom relationships are based upon a dynamic balance between defense and cooperation. A certain degree of competition is necessary to guarantee life spread and development. On the other hand, cooperation is a powerful tool to ensure a long lasting adaptation to changing environmental conditions and to support evolution to a higher level of complexity. Bacteria can interact with their (true or potential) parasites (i.e., phages) and with their multicellular hosts. In these model interactions, bacteria learnt how to cope with their inner and outer host, transforming dangerous signals into opportunities and modulating responses in order to achieve an agreement that is beneficial for the overall participants, thus giving rise to a more complex "organism" or ecosystem. In this review, particular attention will be addressed to underline the minimal energy expenditure required for these successful interactions [e.g., moonlighting proteins, post-translational modifications (PTMs), and multitasking signals] and the systemic vision of these processes and ways of life in which the system proves to be more than the sum of the single components. Using an inside-out perspective, I will examine the possibility of multilevel interactions, in which viruses help bacteria to cope with the animal host and bacteria support the human immune system to counteract viral infection in a circular vision. In this sophisticated network, bacteria represent the precious link that insures system stability with relative low energy expenditure.
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Affiliation(s)
- Enrica Pessione
- Department of Life Sciences and Systems Biology, School of Nature Sciences, Università degli Studi di Torino, Turin, Italy
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11
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Li M, Xi P, Xu Y, Wang Z, Han X, Ren W, Phouthapane V, Miao J. Taurine Attenuates Streptococcus uberis-Induced Bovine Mammary Epithelial Cells Inflammation via Phosphoinositides/Ca 2+ Signaling. Front Immunol 2019; 10:1825. [PMID: 31447841 PMCID: PMC6692464 DOI: 10.3389/fimmu.2019.01825] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 07/18/2019] [Indexed: 12/18/2022] Open
Abstract
Taurine may alleviate the inflammatory injury induced by Streptococcus uberis (S. uberis) infection by regulating intracellular Ca2+ levels. However, the underlying mechanisms remain unclear. Infection leads to subversion of phosphoinositides (PIs) which are closely related to Ca2+ signaling. In order to investigate whether taurine regulates inflammation by means of PIs/ Ca2+ systems, competitive inhibitors of taurine (β-alanine) siTauT, siPAT1, siPLC, siCaN, siPKC, and inhibitors of PLC (U73122), PKC (RO31-8220), and CaN (FK 506) were used. The results indicate that taurine transfers the extracellular nutrient signal for intercellular innate immunity to phosphoinositides without a need to enter the cytoplasm while regulating intracellular Ca2+ levels during inflammation. Both the Ca2+-PKCα-NF-κB, and Ca2+-CaM-CaN-NFAT signaling pathways of S. uberis infection and the regulatory roles of taurine follow activation of PIs/Ca2+ systems. These data increase our understanding on the mechanisms of multifunctional nutrient, taurine attenuated inflammatory responses caused by S. uberis infection, and provide theoretical support for the prevention of this disease.
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Affiliation(s)
- Ming Li
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Panpan Xi
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Yuanyuan Xu
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Zhenglei Wang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Xiangan Han
- Chinese Academy of Agricultural Sciences, Shanghai Veterinary Research Institute, Shanghai, China
| | - Wenkai Ren
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, College of Animal Science, Subtropical Institute of Animal Nutrition and Feed, South China Agricultural University, Guangzhou, China
| | - Vanhnaseng Phouthapane
- Biotechnology and Ecology Institute, Ministry of Science and Technology, Vientiane, Laos
| | - Jinfeng Miao
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
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12
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Bussi C, Gutierrez MG. Mycobacterium tuberculosis infection of host cells in space and time. FEMS Microbiol Rev 2019; 43:341-361. [PMID: 30916769 PMCID: PMC6606852 DOI: 10.1093/femsre/fuz006] [Citation(s) in RCA: 186] [Impact Index Per Article: 37.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2018] [Accepted: 03/26/2019] [Indexed: 12/16/2022] Open
Abstract
Tuberculosis (TB) caused by the bacterial pathogen Mycobacterium tuberculosis (Mtb) remains one of the deadliest infectious diseases with over a billion deaths in the past 200 years (Paulson 2013). TB causes more deaths worldwide than any other single infectious agent, with 10.4 million new cases and close to 1.7 million deaths in 2017. The obstacles that make TB hard to treat and eradicate are intrinsically linked to the intracellular lifestyle of Mtb. Mtb needs to replicate within human cells to disseminate to other individuals and cause disease. However, we still do not completely understand how Mtb manages to survive within eukaryotic cells and why some cells are able to eradicate this lethal pathogen. Here, we summarise the current knowledge of the complex host cell-pathogen interactions in TB and review the cellular mechanisms operating at the interface between Mtb and the human host cell, highlighting the technical and methodological challenges to investigating the cell biology of human host cell-Mtb interactions.
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Affiliation(s)
- Claudio Bussi
- Host-pathogen interactions in tuberculosis laboratory, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, United Kingdom
| | - Maximiliano G Gutierrez
- Host-pathogen interactions in tuberculosis laboratory, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, United Kingdom
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13
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Eisenreich W, Rudel T, Heesemann J, Goebel W. How Viral and Intracellular Bacterial Pathogens Reprogram the Metabolism of Host Cells to Allow Their Intracellular Replication. Front Cell Infect Microbiol 2019; 9:42. [PMID: 30886834 PMCID: PMC6409310 DOI: 10.3389/fcimb.2019.00042] [Citation(s) in RCA: 129] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Accepted: 02/08/2019] [Indexed: 12/12/2022] Open
Abstract
Viruses and intracellular bacterial pathogens (IBPs) have in common the need of suitable host cells for efficient replication and proliferation during infection. In human infections, the cell types which both groups of pathogens are using as hosts are indeed quite similar and include phagocytic immune cells, especially monocytes/macrophages (MOs/MPs) and dendritic cells (DCs), as well as nonprofessional phagocytes, like epithelial cells, fibroblasts and endothelial cells. These terminally differentiated cells are normally in a metabolically quiescent state when they are encountered by these pathogens during infection. This metabolic state of the host cells does not meet the extensive need for nutrients required for efficient intracellular replication of viruses and especially IBPs which, in contrast to the viral pathogens, have to perform their own specific intracellular metabolism to survive and efficiently replicate in their host cell niches. For this goal, viruses and IBPs have to reprogram the host cell metabolism in a pathogen-specific manner to increase the supply of nutrients, energy, and metabolites which have to be provided to the pathogen to allow its replication. In viral infections, this appears to be often achieved by the interaction of specific viral factors with central metabolic regulators, including oncogenes and tumor suppressors, or by the introduction of virus-specific oncogenes. Less is so far known on the mechanisms leading to metabolic reprogramming of the host cell by IBPs. However, the still scant data suggest that similar mechanisms may also determine the reprogramming of the host cell metabolism in IBP infections. In this review, we summarize and compare the present knowledge on this important, yet still poorly understood aspect of pathogenesis of human viral and especially IBP infections.
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Affiliation(s)
- Wolfgang Eisenreich
- Chair of Biochemistry, Department of Chemistry, Technische Universität München, Garching, Germany
| | - Thomas Rudel
- Chair of Microbiology, Biocenter, University of Würzburg, Würzburg, Germany
| | - Jürgen Heesemann
- Max von Pettenkofer-Institute, Ludwig Maximilian University of Munich, Munich, Germany
| | - Werner Goebel
- Max von Pettenkofer-Institute, Ludwig Maximilian University of Munich, Munich, Germany
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14
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Martinez E, Siadous FA, Bonazzi M. Tiny architects: biogenesis of intracellular replicative niches by bacterial pathogens. FEMS Microbiol Rev 2018; 42:425-447. [PMID: 29596635 DOI: 10.1093/femsre/fuy013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 03/26/2018] [Indexed: 11/13/2022] Open
Abstract
Co-evolution of bacterial pathogens with their hosts led to the emergence of a stunning variety of strategies aiming at the evasion of host defences, colonisation of host cells and tissues and, ultimately, the establishment of a successful infection. Pathogenic bacteria are typically classified as extracellular and intracellular; however, intracellular lifestyle comes in many different flavours: some microbes rapidly escape to the cytosol whereas other microbes remain within vacuolar compartments and harness membrane trafficking pathways to generate their host-derived, pathogen-specific replicative niche. Here we review the current knowledge on a variety of vacuolar lifestyles, the effector proteins used by bacteria as tools to take control of the host cell and the main membrane trafficking signalling pathways targeted by vacuolar pathogens as source of membranes and nutrients. Finally, we will also discuss how host cells have developed countermeasures to sense the biogenesis of the aberrant organelles harbouring bacteria. Understanding the dialogue between bacterial and eukaryotic proteins is the key to unravel the molecular mechanisms of infection and in turn, this may lead to the identification of new targets for the development of new antimicrobials.
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Affiliation(s)
- Eric Martinez
- IRIM, University of Montpellier, CNRS, 34293 Montpellier, France
| | | | - Matteo Bonazzi
- IRIM, University of Montpellier, CNRS, 34293 Montpellier, France
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15
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Casasanta MA, Yoo CC, Smith HB, Duncan AJ, Cochrane K, Varano AC, Allen-Vercoe E, Slade DJ. A chemical and biological toolbox for Type Vd secretion: Characterization of the phospholipase A1 autotransporter FplA from Fusobacterium nucleatum. J Biol Chem 2017; 292:20240-20254. [PMID: 29021252 PMCID: PMC5724010 DOI: 10.1074/jbc.m117.819144] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 10/10/2017] [Indexed: 01/28/2023] Open
Abstract
Fusobacterium nucleatum is an oral pathogen that is linked to multiple human infections and colorectal cancer. Strikingly, F. nucleatum achieves virulence in the absence of large, multiprotein secretion systems (Types I, II, III, IV, and VI), which are widely used by Gram-negative bacteria for pathogenesis. By contrast, F. nucleatum strains contain genomic expansions of Type V secreted effectors (autotransporters) that are critical for host cell adherence, invasion, and biofilm formation. Here, we present the first characterization of an F. nucleatum Type Vd phospholipase class A1 autotransporter (strain ATCC 25586, gene FN1704) that we hereby rename Fusobacterium phospholipase autotransporter (FplA). Biochemical analysis of multiple Fusobacterium strains revealed that FplA is expressed as a full-length 85-kDa outer membrane–embedded protein or as a truncated phospholipase domain that remains associated with the outer membrane. Whereas the role of Type Vd secretion in bacteria remains unidentified, we show that FplA binds with high affinity to host phosphoinositide-signaling lipids, revealing a potential role for this enzyme in establishing an F. nucleatum intracellular niche. To further analyze the role of FplA, we developed an fplA gene knock-out strain, which will guide future in vivo studies to determine its potential role in F. nucleatum pathogenesis. In summary, using recombinant FplA constructs, we have identified a biochemical toolbox that includes lipid substrates for enzymatic assays, potent inhibitors, and chemical probes to detect, track, and characterize the role of Type Vd secreted phospholipases in Gram-negative bacteria.
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Affiliation(s)
- Michael A Casasanta
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061
| | - Christopher C Yoo
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061
| | - Hans B Smith
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061
| | - Alison J Duncan
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061
| | - Kyla Cochrane
- Canada's Michael Smith Genome Sciences Centre, British Columbia Cancer Agency, Vancouver, British Columbia V5Z 4S6, Canada; Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada; Department of Biochemistry and Molecular Biology, Simon Fraser University, Vancouver, British Columbia V5A 1S6, Canada
| | - Ann C Varano
- Virginia Tech Carilion Research Institute, Roanoke, Virginia 24016
| | - Emma Allen-Vercoe
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Daniel J Slade
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061.
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16
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Liebl D, Qi X, Zhe Y, Barnett TC, Teasdale RD. SopB-Mediated Recruitment of SNX18 Facilitates Salmonella Typhimurium Internalization by the Host Cell. Front Cell Infect Microbiol 2017; 7:257. [PMID: 28664153 PMCID: PMC5471308 DOI: 10.3389/fcimb.2017.00257] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 05/31/2017] [Indexed: 11/16/2022] Open
Abstract
To invade epithelial cells, Salmonella enterica serovar Typhimurium (S. Typhimurium) induces macropinocytosis through the action of virulence proteins delivered across the host cell membrane via a type III secretion system. We show that after docking at the plasma membrane S. Typhimurium triggers rapid recruitment of cytosolic SNX18, a SH3-PX-BAR domain sorting nexin protein, to the bacteria-induced membrane ruffles and to the nascent Salmonella-containing vacuole. SNX18 recruitment required the inositol-phosphatase activity of the Salmonella effector SopB and an intact phosphoinositide-binding site within the PX domain of SNX18, but occurred independently of Rho-GTPases Rac1 and Cdc42 activation. SNX18 promotes formation of the SCV from the plasma membrane by acting as a scaffold to recruit Dynamin-2 and N-WASP in a process dependent on the SH3 domain of SNX18. Quantification of bacteria uptake revealed that overexpression of SNX18 increased bacteria internalization, whereas a decrease was detected in cells overexpressing the phosphoinositide-binding mutant R303Q, the ΔSH3 mutant, and in cells where endogenous levels of SNX18 were knocked-down. This study identifies SNX18 as a novel target of SopB and suggests a mechanism where S. Typhimurium engages host factors via local manipulation of phosphoinositide composition at the site of invasion to orchestrate the internalization process.
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Affiliation(s)
- David Liebl
- Institute for Molecular Bioscience, The University of QueenslandBrisbane, QLD, Australia
| | - Xiaying Qi
- Institute for Molecular Bioscience, The University of QueenslandBrisbane, QLD, Australia
| | - Yang Zhe
- Institute for Molecular Bioscience, The University of QueenslandBrisbane, QLD, Australia
| | - Timothy C Barnett
- Australian Infectious Diseases Research Centre, The University of QueenslandBrisbane, QLD, Australia.,School of Chemistry and Molecular Biosciences, The University of QueenslandBrisbane, QLD, Australia
| | - Rohan D Teasdale
- Institute for Molecular Bioscience, The University of QueenslandBrisbane, QLD, Australia.,Australian Infectious Diseases Research Centre, The University of QueenslandBrisbane, QLD, Australia.,School of Biomedical Sciences, The University of QueenslandBrisbane, QLD, Australia
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17
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Zozaya-Valdés E, Roth-Schulze AJ, Egan S, Thomas T. Microbial community function in the bleaching disease of the marine macroalgae Delisea pulchra. Environ Microbiol 2017; 19:3012-3024. [PMID: 28419766 DOI: 10.1111/1462-2920.13758] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 04/07/2017] [Indexed: 01/10/2023]
Abstract
Disease is increasingly viewed as a major factor impacting the health of both natural and cultured populations of marine organisms, including macroalgae. The red macroalga Delisea pulchra suffers from a bleaching disease resulting from host stress and infection by opportunistic bacterial pathogens. However, how pathogens cause the disease and how the entire macro algal-associated community is involved in the process is unclear. Here, we perform a metagenomic analysis of microbial communities associated with diseased and healthy D. pulchra across multiple bleaching events. Analysis of reconstructed 16S rRNA gene sequences showed that bacteria belonging to the families Rhodobacteraceae, Saprospiraceae and Flavobacteriaceae, including bacteria previously implicated in algal bleaching, to be enriched in diseased D. pulchra. Genes with predicted functions related to chemotaxis, motility, oxidative stress response, vitamin biosynthesis and nutrient acquisition were also prevalent in microbiomes of bleached algae, which may have a role in pathogenicity. Reconstruction of genomes that were abundant on bleached samples revealed that no single organism contains all bleaching-enriched functional genes. This observation indicates that potential virulence traits are distributed across multiple bacteria and that the disease in D. pulchra may result from a consortium of opportunistic pathogens, analogous to dysbiotic or polymicrobial diseases.
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Affiliation(s)
- Enrique Zozaya-Valdés
- Centre for Marine Bio-Innovation, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Alexandra J Roth-Schulze
- Centre for Marine Bio-Innovation, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Suhelen Egan
- Centre for Marine Bio-Innovation, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Torsten Thomas
- Centre for Marine Bio-Innovation, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW, 2052, Australia
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18
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Liposomes loaded with bioactive lipids enhance antibacterial innate immunity irrespective of drug resistance. Sci Rep 2017; 7:45120. [PMID: 28345623 PMCID: PMC5366871 DOI: 10.1038/srep45120] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 01/27/2017] [Indexed: 12/26/2022] Open
Abstract
Phagocytosis is a key mechanism of innate immunity, and promotion of phagosome maturation may represent a therapeutic target to enhance antibacterial host response. Phagosome maturation is favored by the timely and coordinated intervention of lipids and may be altered in infections. Here we used apoptotic body-like liposomes (ABL) to selectively deliver bioactive lipids to innate cells, and then tested their function in models of pathogen-inhibited and host-impaired phagosome maturation. Stimulation of macrophages with ABLs carrying phosphatidic acid (PA), phosphatidylinositol 3-phosphate (PI3P) or PI5P increased intracellular killing of BCG, by inducing phagosome acidification and ROS generation. Moreover, ABLs carrying PA or PI5P enhanced ROS-mediated intracellular killing of Pseudomonas aeruginosa, in macrophages expressing a pharmacologically-inhibited or a naturally-mutated cystic fibrosis transmembrane conductance regulator. Finally, we show that bronchoalveolar lavage cells from patients with drug-resistant pulmonary infections increased significantly their capacity to kill in vivo acquired bacterial pathogens when ex vivo stimulated with PA- or PI5P-loaded ABLs. Altogether, these results provide the proof of concept of the efficacy of bioactive lipids delivered by ABL to enhance phagosome maturation dependent antimicrobial response, as an additional host-directed strategy aimed at the control of chronic, recurrent or drug-resistant infections.
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19
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Shao Y, Li C, Xu W, Zhang P, Zhang W, Zhao X. miR-31 Links Lipid Metabolism and Cell Apoptosis in Bacteria-Challenged Apostichopus japonicus via Targeting CTRP9. Front Immunol 2017; 8:263. [PMID: 28348559 PMCID: PMC5346533 DOI: 10.3389/fimmu.2017.00263] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 02/23/2017] [Indexed: 12/23/2022] Open
Abstract
The biological functions of microRNAs (miRNAs) have been studied in a number of eukaryotic species. Recent studies on vertebrate animals have demonstrated critical roles of miRNA in immune and metabolic activities. However, studies on the functions of miRNA in invertebrates are very limited. Here, we demonstrated that miR-31 from Apostichopus japonicus disrupts the balance of lipid metabolism, thus resulting in cell apoptosis by targeting complement C1q tumor necrosis factor-related protein 9 (AjCTRP9), a novel adipokine with pleiotropic functions in immunity and metabolism. Lipidomic analysis suggested that the intercellular lipid metabolites were markedly altered, and three ceramide (Cer) species synchronously increased in the AjCTRP9-silenced coelomocytes. Moreover, exogenous Cer exposure significantly induced apoptosis in the coelomocytes in vivo, in agreement with findings from miR-31 mimic- or AjCTRP9 small-interfering RNA-transfected coelomocytes. Furthermore, we found that the imbalance in sphingolipid metabolism triggered by the overproduction of Cers ultimately resulted in the activation of the apoptosis initiator caspase-8 and executioner caspase-3. Our findings provide the first direct evidence that miR-31 negatively modulates the expression of AjCTRP9 and disturbance of Cer channels, thus leading to caspase-3- and caspase-8-dependent apoptosis, during the interactions between pathogens and host.
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Affiliation(s)
- Yina Shao
- School of Marine Sciences, Ningbo University , Ningbo , China
| | - Chenghua Li
- School of Marine Sciences, Ningbo University , Ningbo , China
| | - Wei Xu
- Agricultural Center, Louisiana State University , Baton Rouge, LA , USA
| | - Pengjuan Zhang
- School of Marine Sciences, Ningbo University , Ningbo , China
| | - Weiwei Zhang
- School of Marine Sciences, Ningbo University , Ningbo , China
| | - Xuelin Zhao
- School of Marine Sciences, Ningbo University , Ningbo , China
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20
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Paciullo F, Fallarino F, Bianconi V, Mannarino MR, Sahebkar A, Pirro M. PCSK9 at the crossroad of cholesterol metabolism and immune function during infections. J Cell Physiol 2017; 232:2330-2338. [DOI: 10.1002/jcp.25767] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2017] [Accepted: 01/05/2017] [Indexed: 12/12/2022]
Affiliation(s)
- Francesco Paciullo
- Department of Medicine, Unit of Internal Medicine; University of Perugia; Perugia Italy
| | - Francesca Fallarino
- Department of Experimental Medicine, Unit of Pharmacology; University of Perugia; Perugia Italy
| | - Vanessa Bianconi
- Department of Medicine, Unit of Internal Medicine; University of Perugia; Perugia Italy
| | - Massimo R. Mannarino
- Department of Medicine, Unit of Internal Medicine; University of Perugia; Perugia Italy
| | - Amirhossein Sahebkar
- Biotechnology Research Center; Mashhad University of Medical Sciences; Mashhad Iran
| | - Matteo Pirro
- Department of Medicine, Unit of Internal Medicine; University of Perugia; Perugia Italy
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21
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Divergent Transcriptional Responses to Physiological and Xenobiotic Stress in Giardia duodenalis. Antimicrob Agents Chemother 2016; 60:6034-45. [PMID: 27458219 DOI: 10.1128/aac.00977-16] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 07/19/2016] [Indexed: 12/22/2022] Open
Abstract
Understanding how parasites respond to stress can help to identify essential biological processes. Giardia duodenalis is a parasitic protist that infects the human gastrointestinal tract and causes 200 to 300 million cases of diarrhea annually. Metronidazole, a major antigiardial drug, is thought to cause oxidative damage within the infective trophozoite form. However, treatment efficacy is suboptimal, due partly to metronidazole-resistant infections. To elucidate conserved and stress-specific responses, we calibrated sublethal metronidazole, hydrogen peroxide, and thermal stresses to exert approximately equal pressure on trophozoite growth and compared transcriptional responses after 24 h of exposure. We identified 252 genes that were differentially transcribed in response to all three stressors, including glycolytic and DNA repair enzymes, a mitogen-activated protein (MAP) kinase, high-cysteine membrane proteins, flavin adenine dinucleotide (FAD) synthetase, and histone modification enzymes. Transcriptional responses appeared to diverge according to physiological or xenobiotic stress. Downregulation of the antioxidant system and α-giardins was observed only under metronidazole-induced stress, whereas upregulation of GARP-like transcription factors and their subordinate genes was observed in response to hydrogen peroxide and thermal stressors. Limited evidence was found in support of stress-specific response elements upstream of differentially transcribed genes; however, antisense derepression and differential regulation of RNA interference machinery suggest multiple epigenetic mechanisms of transcriptional control.
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22
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Coxiella burnetii effector CvpB modulates phosphoinositide metabolism for optimal vacuole development. Proc Natl Acad Sci U S A 2016; 113:E3260-9. [PMID: 27226300 DOI: 10.1073/pnas.1522811113] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The Q fever bacterium Coxiella burnetii replicates inside host cells within a large Coxiella-containing vacuole (CCV) whose biogenesis relies on the Dot/Icm-dependent secretion of bacterial effectors. Several membrane trafficking pathways contribute membranes, proteins, and lipids for CCV biogenesis. These include the endocytic and autophagy pathways, which are characterized by phosphatidylinositol 3-phosphate [PI(3)P]-positive membranes. Here we show that the C. burnetii secreted effector Coxiella vacuolar protein B (CvpB) binds PI(3)P and phosphatidylserine (PS) on CCVs and early endosomal compartments and perturbs the activity of the phosphatidylinositol 5-kinase PIKfyve to manipulate PI(3)P metabolism. CvpB association to early endosome triggers vacuolation and clustering, leading to the channeling of large PI(3)P-positive membranes to CCVs for vacuole expansion. At CCVs, CvpB binding to early endosome- and autophagy-derived PI(3)P and the concomitant inhibition of PIKfyve favor the association of the autophagosomal machinery to CCVs for optimal homotypic fusion of the Coxiella-containing compartments. The importance of manipulating PI(3)P metabolism is highlighted by mutations in cvpB resulting in a multivacuolar phenotype, rescuable by gene complementation, indicative of a defect in CCV biogenesis. Using the insect model Galleria mellonella, we demonstrate the in vivo relevance of defective CCV biogenesis by highlighting an attenuated virulence phenotype associated with cvpB mutations.
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23
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Dutta NK, He R, Pinn ML, He Y, Burrows F, Zhang ZY, Karakousis PC. Mycobacterial Protein Tyrosine Phosphatases A and B Inhibitors Augment the Bactericidal Activity of the Standard Anti-tuberculosis Regimen. ACS Infect Dis 2016; 2:231-239. [PMID: 27478867 DOI: 10.1021/acsinfecdis.5b00133] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Novel drugs are required to shorten the duration of treatment for tuberculosis (TB) and to combat the emergence of drug resistance. One approach has been to identify and target Mycobacterium tuberculosis (Mtb) virulence factors, which promote the establishment of TB infection and pathogenesis. Mtb produces a number of virulence factors, including two protein tyrosine phosphatases (PTPs), mPTPA and mPTPB, to evade the antimicrobial functions of host macrophages. To assess the therapeutic potential of targeting the virulent Mtb PTPs, we developed highly potent and selective inhibitors of mPTPA (L335-M34) and mPTPB (L01-Z08) with drug-like properties. We tested the bactericidal activity of L335-M34 and L01-Z08 alone or together in combination with the standard antitubercular regimen of isoniazid-rifampicin-pyrazinamide (HRZ) in the guinea pig model of chronic TB infection, which faithfully recapitulates some of the key histological features of human TB lesions. Following a single dose of L335-M34 50mg/kg and L01-Z08 20 mg/kg, plasma levels were maintained at levels 10-fold greater than the biochemical IC50 for 12-24 hours. Although neither PTP inhibitor alone significantly enhanced the antibacterial activity of HRZ, dual inhibition of mPTPA and mPTPB in combination with HRZ showed modest synergy, even after 2 weeks of treatment. After 6 weeks of treatment, the degree of lung inflammation correlated with the bactericidal activity of each drug regimen. This study highlights the potential utility of targeting Mtb virulence factors, and specifically the Mtb PTPs, as a strategy for enhancing the activity of standard anti-TB treatment.
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Affiliation(s)
- Noton K. Dutta
- Center for Tuberculosis
Research, Department of Medicine, Johns Hopkins University School of Medicine, 1551 East Jefferson Street, Baltimore, Maryland 21287, United States
| | - Rongjun He
- Department of Biochemistry and Molecular
Biology Indiana University School of Medicine, 635 Barnhill Drive, MS 4053, Indianapolis, Indiana 46202, United States
| | - Michael L. Pinn
- Center for Tuberculosis
Research, Department of Medicine, Johns Hopkins University School of Medicine, 1551 East Jefferson Street, Baltimore, Maryland 21287, United States
| | - Yantao He
- Department of Biochemistry and Molecular
Biology Indiana University School of Medicine, 635 Barnhill Drive, MS 4053, Indianapolis, Indiana 46202, United States
| | - Francis Burrows
- Aarden Pharmaceuticals, Inc., 351 West 10th Street, Suite 248, Indianapolis, Indiana 46202, United States
| | - Zhong-Yin Zhang
- Department of Biochemistry and Molecular
Biology Indiana University School of Medicine, 635 Barnhill Drive, MS 4053, Indianapolis, Indiana 46202, United States
| | - Petros C. Karakousis
- Center for Tuberculosis
Research, Department of Medicine, Johns Hopkins University School of Medicine, 1551 East Jefferson Street, Baltimore, Maryland 21287, United States
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, Maryland 21205, United States
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24
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Helms JB, Kaloyanova DV, Strating JRP, van Hellemond JJ, van der Schaar HM, Tielens AGM, van Kuppeveld FJM, Brouwers JF. Targeting of the hydrophobic metabolome by pathogens. Traffic 2016; 16:439-60. [PMID: 25754025 PMCID: PMC7169838 DOI: 10.1111/tra.12280] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Revised: 01/09/2015] [Accepted: 01/09/2015] [Indexed: 12/12/2022]
Abstract
The hydrophobic molecules of the metabolome – also named the lipidome – constitute a major part of the entire metabolome. Novel technologies show the existence of a staggering number of individual lipid species, the biological functions of which are, with the exception of only a few lipid species, unknown. Much can be learned from pathogens that have evolved to take advantage of the complexity of the lipidome to escape the immune system of the host organism and to allow their survival and replication. Different types of pathogens target different lipids as shown in interaction maps, allowing visualization of differences between different types of pathogens. Bacterial and viral pathogens target predominantly structural and signaling lipids to alter the cellular phenotype of the host cell. Fungal and parasitic pathogens have complex lipidomes themselves and target predominantly the release of polyunsaturated fatty acids from the host cell lipidome, resulting in the generation of eicosanoids by either the host cell or the pathogen. Thus, whereas viruses and bacteria induce predominantly alterations in lipid metabolites at the host cell level, eukaryotic pathogens focus on interference with lipid metabolites affecting systemic inflammatory reactions that are part of the immune system. A better understanding of the interplay between host–pathogen interactions will not only help elucidate the fundamental role of lipid species in cellular physiology, but will also aid in the generation of novel therapeutic drugs.
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Affiliation(s)
- J Bernd Helms
- Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine & Institute of Biomembranes, Utrecht University, Yalelaan 2, 3584 CM, Utrecht, The Netherlands
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25
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Wasilko DJ, Mao Y. Exploiting the ubiquitin and phosphoinositide pathways by the Legionella pneumophila effector, SidC. Curr Genet 2015; 62:105-8. [PMID: 26433729 DOI: 10.1007/s00294-015-0521-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 09/13/2015] [Accepted: 09/14/2015] [Indexed: 01/29/2023]
Abstract
Intracellular bacterial pathogens use secreted effector proteins to alter host cellular processes, with the goal of subverting host defenses and allowing the infection to progress. One such pathogen, Legionella pneumophila, secretes ~300 proteins into its host to alter a number of pathways including intracellular trafficking, phosphoinositide metabolism, and cell signaling. The Legionella effector SidC was previously found to bind to PI(4)P and was responsible for the enrichment of ER proteins and ubiquitinated species on the Legionella-containing vacuoles. Through our recent work, we have discovered that SidC contains a unique N-terminal E3 ubiquitin ligase domain and a C-terminal novel PI(4)P-binding domain. Our results demonstrate that SidC serves to link two distinct cellular pathways, ubiquitin and phosphoinositide. However, how the ubiquitin ligase activity regulates host membrane trafficking events remains to be investigated.
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Affiliation(s)
- David J Wasilko
- Weill Institute for Cell and Molecular Biology and Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, 14853, USA
| | - Yuxin Mao
- Weill Institute for Cell and Molecular Biology and Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, 14853, USA.
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26
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The impact of phosphorus on the immune system and the intestinal microbiota with special focus on the pig. Nutr Res Rev 2015; 28:67-82. [PMID: 26004147 DOI: 10.1017/s0954422415000049] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
There is increasing interest in dietary ingredients that are appropriate to support digestive and immune functions, but also maintain a stable microbial ecosystem in the gastrointestinal tract (GIT), particularly in weaned pigs. P is an essential nutrient for both microbes and their host, as it is involved, for example, in bone formation, energy metabolism, cellular signalling and stabilisation of cell membranes. Non-ruminant animals have limited access to phytate, the main storage form of P in plant seeds. The release of P bound to phytate requires phytase activity of plant or microbial origin, resulting in the formation of variable phosphorylated inositol phosphates (InsPs). The present review focuses on interactions between variations in dietary P supply, the immune system of the host, and the intestinal microbial ecosystem. Although results on the interaction between P and the immune system are inconsistent, several studies in different species have shown a positive impact of dietary P and phytase addition on the adaptive immune response. Recent studies with pigs suggest that P supply may influence intestinal microbial composition and activity. Individual InsPs or phosphate may also affect properties of pathogenic micro-organisms, such as metabolism or virulence. In conclusion, P may be considered as part of an integrated approach to support immune functions and maintain a stable microbial ecosystem in the GIT, thereby providing a barrier against potential pathogens. Within this regard, differences in phytate-P content and intrinsic phytase activity of plant feedstuffs, as well as the formation of individual InsPs, have to be taken into account.
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27
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de Azevedo-Martins AC, Alves JMP, de Mello FG, Vasconcelos ATR, de Souza W, Einicker-Lamas M, Motta MCM. Biochemical and phylogenetic analyses of phosphatidylinositol production in Angomonas deanei, an endosymbiont-harboring trypanosomatid. Parasit Vectors 2015; 8:247. [PMID: 25903782 PMCID: PMC4424895 DOI: 10.1186/s13071-015-0854-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Accepted: 04/13/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The endosymbiosis in trypanosomatids is characterized by co-evolution between one bacterium and its host protozoan in a mutualistic relationship, thus constituting an excellent model to study organelle origin in the eukaryotic cell. In this association, an intense metabolic exchange is observed between both partners: the host provides energetic molecules and a stable environment to a reduced wall symbiont, while the bacterium is able to interfere in host metabolism by enhancing phospholipid production and completing essential biosynthesis pathways, such as amino acids and hemin production. The bacterium envelope presents a reduced cell wall which is mainly composed of cardiolipin and phosphatidylcholine, being the latter only common in intracellular prokaryotes. Phosphatidylinositol (PI) is also present in the symbiont and host cell membranes. This phospholipid is usually related to cellular signaling and to anchor surface molecules, which represents important events for cellular interactions. METHODS In order to investigate the production of PI and its derivatives in symbiont bearing trypanosomatids, aposymbiotic and wild type strains of Angomonas deanei, as well as isolated symbionts, were incubated with [(3)H]myo-inositol and the incorporation of this tracer was analyzed into inositol-containing molecules, mainly phosphoinositides and lipoproteins. Gene searches and their phylogenies were also performed in order to investigate the PI synthesis in symbiontbearing trypanosomatids. RESULTS Our results showed that the bacterium did not incorporate the tracer and that both strains produced similar quantities of PI and its derivatives, indicating that the symbiont does not influence the production of these metabolites. Gene searches related to PI synthesis revealed that the trypanosomatid genome contains an inositol transporter, PI synthase and the myo-inositol synthase. Thus, the host is able to produce PI either from exogenous myo-inositol (inositol transporter) or from myo-inositol synthesized de novo. Phylogenetic analysis using other organisms as references indicated that, in trypanosomatids, the genes involved in PI synthesis have a monophyletic origin. In accordance with experimental data, sequences for myo-inositol transport or for myo-inositol and PI biosynthesis were not found in the symbiont. CONCLUSIONS Altogether, our results indicate that the bacterium depends on the host to obtain PI.
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Affiliation(s)
- Allan C de Azevedo-Martins
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, UFRJ, Avenida Carlos Chagas Filho, 343, Bloco G, Subsolo, Cidade Universitária, Ilha do Fundão, Rio de Janeiro, CEP 21941-590, Brazil. .,Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagens, Rio de Janeiro, Brazil. .,Laboratório Nacional de Computação Científica, Av. Getúlio Vargas, 333, Quitandinha, Petrópolis, RJ, CEP: 25651-075, Brazil.
| | - João M P Alves
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
| | - Fernando Garcia de Mello
- Laboratório de Neuroquímica, Instituto de Biofísica Carlos Chagas Filho, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, UFRJ, Avenida Carlos Chagas Filho, 343, Bloco C, Cidade Universitária, Ilha do Fundão, Rio de Janeiro, CEP 21941-590, Brazil.
| | - Ana Tereza R Vasconcelos
- Laboratório Nacional de Computação Científica, Av. Getúlio Vargas, 333, Quitandinha, Petrópolis, RJ, CEP: 25651-075, Brazil.
| | - Wanderley de Souza
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, UFRJ, Avenida Carlos Chagas Filho, 343, Bloco G, Subsolo, Cidade Universitária, Ilha do Fundão, Rio de Janeiro, CEP 21941-590, Brazil. .,Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagens, Rio de Janeiro, Brazil. .,Instituto Nacional de Metrologia, Qualidade e Tecnologia - Inmetro, Rio de Janeiro, RJ, Brasil.
| | - Marcelo Einicker-Lamas
- Laboratório de Biomembranas, Instituto de Biofísica Carlos Chagas Filho, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, UFRJ, Avenida Carlos Chagas Filho, 343, Bloco G, Cidade Universitária, Ilha do Fundão, Rio de Janeiro, CEP 21941-590, Brazil.
| | - Maria Cristina M Motta
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, UFRJ, Avenida Carlos Chagas Filho, 343, Bloco G, Subsolo, Cidade Universitária, Ilha do Fundão, Rio de Janeiro, CEP 21941-590, Brazil. .,Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagens, Rio de Janeiro, Brazil.
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28
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Zheng K, Kitazato K, Wang Y, He Z. Pathogenic microbes manipulate cofilin activity to subvert actin cytoskeleton. Crit Rev Microbiol 2015; 42:677-95. [PMID: 25853495 DOI: 10.3109/1040841x.2015.1010139] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Actin-depolymerizing factor (ADF)/cofilin proteins are key players in controlling the temporal and spatial extent of actin dynamics, which is crucial for mediating host-pathogen interactions. Pathogenic microbes have evolved molecular mechanisms to manipulate cofilin activity to subvert the actin cytoskeletal system in host cells, promoting their internalization into the target cells, modifying the replication niche and facilitating their intracellular and intercellular dissemination. The study of how these pathogens exploit cofilin pathways is crucial for understanding infectious disease and providing potential targets for drug therapies.
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Affiliation(s)
- Kai Zheng
- a Department of Pharmacy, School of Medicine , Shenzhen University , Shenzhen , Guangdong , People's Republic of China .,c Guangzhou Jinan Biomedicine Research and Development Center, National Engineering Research Center of Genetic Medicine, Jinan University , Guangzhou , China
| | - Kaio Kitazato
- b Division of Molecular Pharmacology of Infectious Agents, Department of Molecular Microbiology and Immunology , Nagasaki University , Nagasaki , Japan , and
| | - Yifei Wang
- c Guangzhou Jinan Biomedicine Research and Development Center, National Engineering Research Center of Genetic Medicine, Jinan University , Guangzhou , China
| | - Zhendan He
- a Department of Pharmacy, School of Medicine , Shenzhen University , Shenzhen , Guangdong , People's Republic of China
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29
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Hsu F, Mao Y. The structure of phosphoinositide phosphatases: Insights into substrate specificity and catalysis. Biochim Biophys Acta Mol Cell Biol Lipids 2014; 1851:698-710. [PMID: 25264170 DOI: 10.1016/j.bbalip.2014.09.015] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Revised: 09/10/2014] [Accepted: 09/17/2014] [Indexed: 12/17/2022]
Abstract
Phosphoinositides (PIs) are a group of key signaling and structural lipid molecules involved in a myriad of cellular processes. PI phosphatases, together with PI kinases, are responsible for the conversion of PIs between distinctive phosphorylation states. PI phosphatases are a large collection of enzymes that are evolved from at least two disparate ancestors. One group is distantly related to endonucleases, which apply divalent metal ions for phosphoryl transfer. The other group is related to protein tyrosine phosphatases, which contain a highly conserved active site motif Cys-X5-Arg (CX5R). In this review, we focus on structural insights to illustrate current understandings of the molecular mechanisms of each PI phosphatase family, with emphasis on their structural basis for substrate specificity determinants and catalytic mechanisms. This article is part of a Special Issue entitled Phosphoinositides.
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Affiliation(s)
- FoSheng Hsu
- Weill Institute for Cell and Molecular Biology and Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Yuxin Mao
- Weill Institute for Cell and Molecular Biology and Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA.
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30
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Pizarro-Cerdá J, Kühbacher A, Cossart P. Phosphoinositides and host-pathogen interactions. Biochim Biophys Acta Mol Cell Biol Lipids 2014; 1851:911-8. [PMID: 25241942 DOI: 10.1016/j.bbalip.2014.09.011] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Revised: 09/09/2014] [Accepted: 09/10/2014] [Indexed: 01/08/2023]
Abstract
Phosphoinositides control key cellular processes including vesicular trafficking and actin polymerization. Intracellular bacterial pathogens manipulate phosphoinositide metabolism in order to promote their uptake by target cells and to direct in some cases the biogenesis of their replication compartments. In this chapter, we review the molecular strategies that major pathogens including Listeria, Mycobacterium, Shigella, Salmonella, Legionella and Yersinia use to hijack phosphoinositides during infection. This article is part of a Special Issue entitled Phosphoinositides.
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Affiliation(s)
- Javier Pizarro-Cerdá
- Institut Pasteur, Unité des Interactions Bactéries-Cellules, F-75015 Paris, France; INSERM, U604, F-75015 Paris, France; INRA, USC2020, F-75015 Paris, France
| | - Andreas Kühbacher
- Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB, Department of Molecular Biotechnology, Stuttgart G-70569, Germany
| | - Pascale Cossart
- Institut Pasteur, Unité des Interactions Bactéries-Cellules, F-75015 Paris, France; INSERM, U604, F-75015 Paris, France; INRA, USC2020, F-75015 Paris, France
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31
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Abstract
Of the many pathogens that infect humans and animals, a large number use cells of the host organism as protected sites for replication. To reach the relevant intracellular compartments, they take advantage of the endocytosis machinery and exploit the network of endocytic organelles for penetration into the cytosol or as sites of replication. In this review, we discuss the endocytic entry processes used by viruses and bacteria and compare the strategies used by these dissimilar classes of pathogens.
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Affiliation(s)
- Pascale Cossart
- Institut Pasteur, Unité des Interactions Bactéries-Cellules, Paris F-75015, France; INSERM U604, Paris F-75015, France; and INRA, USC2020, Paris F-75015, France
| | - Ari Helenius
- Institute of Biochemistry, ETH Zurich, 8093 Zurich, Switzerland
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32
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Sato H, Frank DW. Intoxication of host cells by the T3SS phospholipase ExoU: PI(4,5)P2-associated, cytoskeletal collapse and late phase membrane blebbing. PLoS One 2014; 9:e103127. [PMID: 25061861 PMCID: PMC4111512 DOI: 10.1371/journal.pone.0103127] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Accepted: 06/27/2014] [Indexed: 01/09/2023] Open
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen that is associated with hospital-acquired infections, ventilator-associated pneumonia, and morbidity of immunocompromised individuals. A subpopulation of P. aeruginosa encodes a protein, ExoU, which exhibits acute cytotoxicity. Toxicity is directly related to the phospholipase A2 activity of the protein after injection into the host cytoplasm via a type III secretion system. ExoU enzymatic activity requires eukaryotic cofactors, ubiquitin or ubiquitin-modified proteins. When administered extracellularly, ExoU is unable to intoxicate epithelial cells in culture, even in the presence of the cofactor. Injection or transfection of ExoU is necessary to observe the acute cytotoxic response. Biochemical approaches indicate that ExoU possesses high affinity to a multifunctional phosphoinositide, phosphatidylinositol 4,5-bisphosphate or PI(4,5)P2 and that it is capable of utilizing this phospholipid as a substrate. In eukaryotic cells, PI(4,5)P2 is mainly located in the cytoplasmic side of the plasma membrane and anchors adaptor proteins that are involved in cytoskeletal structures, focal adhesions, and plasma membranes. Time-lapse fluorescent microscopy analyses of infected live cells demonstrate that ExoU intoxication correlates with intracellular damage in the early phases of infection, such as disruption of focal adhesions, cytoskeletal collapse, actin depolymerization, and cell rounding. At later time points, a membrane blebbing phenotype was prominent prior to the loss of the plasma membrane integrity and barrier function. Membrane blebbing appears to accelerate membrane rupture and the release of intracellular markers. Our data suggest that in eukaryotic host cells, intracellular ExoU targets and hydrolyzes PI(4,5)P2 on the plasma membrane, causing a subsequent disruption of cellular structures and membrane integrity.
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Affiliation(s)
- Hiromi Sato
- Center for Infectious Disease Research, Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- * E-mail:
| | - Dara W. Frank
- Center for Infectious Disease Research, Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
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33
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The Legionella longbeachae Icm/Dot substrate SidC selectively binds phosphatidylinositol 4-phosphate with nanomolar affinity and promotes pathogen vacuole-endoplasmic reticulum interactions. Infect Immun 2014; 82:4021-33. [PMID: 25024371 DOI: 10.1128/iai.01685-14] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Legionella spp. cause the severe pneumonia Legionnaires' disease. The environmental bacteria replicate intracellularly in free-living amoebae and human alveolar macrophages within a distinct, endoplasmic reticulum (ER)-derived compartment termed the Legionella-containing vacuole (LCV). LCV formation requires the bacterial Icm/Dot type IV secretion system (T4SS) that translocates into host cells a plethora of different "effector" proteins, some of which anchor to the pathogen vacuole by binding to phosphoinositide (PI) lipids. Here, we identified by unbiased pulldown assays in Legionella longbeachae lysates a 111-kDa SidC homologue as the major phosphatidylinositol 4-phosphate [PtdIns(4)P]-binding protein. The PI-binding domain was mapped to a 20-kDa P4C [PtdIns(4)P binding of SidC] fragment. Isothermal titration calorimetry revealed that SidC of L. longbeachae (SidC(Llo)) binds PtdIns(4)P with a K(d) (dissociation constant) of 71 nM, which is 3 to 4 times lower than that of the SidC orthologue of Legionella pneumophila (SidC(Lpn)). Upon infection of RAW 264.7 macrophages with L. longbeachae, endogenous SidC(Llo) or ectopically produced SidC(Lpn) localized in an Icm/Dot-dependent manner to the PtdIns(4)P-positive LCVs. An L. longbeachae ΔsidC deletion mutant was impaired for calnexin recruitment to LCVs in Dictyostelium discoideum amoebae and outcompeted by wild-type bacteria in Acanthamoeba castellanii. Calnexin recruitment was restored by SidC(Llo) or its orthologues SidC(Lpn) and SdcA(Lpn). Conversely, calnexin recruitment was restored by SidC(Llo) in L. pneumophila lacking sidC and sdcA. Together, biochemical, genetic, and cell biological data indicate that SidC(Llo) is an L. longbeachae effector that binds through a P4C domain with high affinity to PtdIns(4)P on LCVs, promotes ER recruitment to the LCV, and thus plays a role in pathogen-host interactions.
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Hubber A, Arasaki K, Nakatsu F, Hardiman C, Lambright D, De Camilli P, Nagai H, Roy CR. The machinery at endoplasmic reticulum-plasma membrane contact sites contributes to spatial regulation of multiple Legionella effector proteins. PLoS Pathog 2014; 10:e1004222. [PMID: 24992562 PMCID: PMC4081824 DOI: 10.1371/journal.ppat.1004222] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2013] [Accepted: 05/16/2014] [Indexed: 11/18/2022] Open
Abstract
The Dot/Icm system of the intracellular pathogen Legionella pneumophila has the capacity to deliver over 270 effector proteins into host cells during infection. Important questions remain as to spatial and temporal mechanisms used to regulate such a large array of virulence determinants after they have been delivered into host cells. Here we investigated several L. pneumophila effector proteins that contain a conserved phosphatidylinositol-4-phosphate (PI4P)-binding domain first described in the effector DrrA (SidM). This PI4P binding domain was essential for the localization of effectors to the early L. pneumophila-containing vacuole (LCV), and DrrA-mediated recruitment of Rab1 to the LCV required PI4P-binding activity. It was found that the host cell machinery that regulates sites of contact between the plasma membrane (PM) and the endoplasmic reticulum (ER) modulates PI4P dynamics on the LCV to control localization of these effectors. Specifically, phosphatidylinositol-4-kinase IIIα (PI4KIIIα) was important for generating a PI4P signature that enabled L. pneumophila effectors to localize to the PM-derived vacuole, and the ER-associated phosphatase Sac1 was involved in metabolizing the PI4P on the vacuole to promote the dissociation of effectors. A defect in L. pneumophila replication in macrophages deficient in PI4KIIIα was observed, highlighting that a PM-derived PI4P signature is critical for biogenesis of a vacuole that supports intracellular multiplication of L. pneumophila. These data indicate that PI4P metabolism by enzymes controlling PM-ER contact sites regulate the association of L. pneumophila effectors to coordinate early stages of vacuole biogenesis. The intracellular pathogen Legionella pneumophila encodes at least 270 effectors that modulate trafficking of the pathogen-occupied vacuole. The mechanisms by which effectors are controlled in host cells are of key interest. Spatial and temporal regulation of effector function has been proposed to involve effector binding to host phosphoinositides. We present results showing that L. pneumophila utilizes the host kinase PI4KIIIα to generate PI4P on the bacterial vacuole and this signature mediates the localization of DrrA and subsequent recruitment of the GTPase Rab1. Additionally, it was found that the host PI4P phosphatase Sac1 was involved in consuming PI4P on the vacuole, which reduced DrrA-mediated recruitment of Rab1 to the LCV. Our data supports the recent concept that PI4KIIIα is important for generation of the plasma-membrane pool of PI4P in host cells, and demonstrates a functional consequence for PI4P-binding by an L. pneumophila effector protein.
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Affiliation(s)
- Andree Hubber
- Section of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, United States of America
- Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka, Japan
- * E-mail: (AH); (CRR)
| | - Kohei Arasaki
- Section of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, United States of America
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Horinouchi, Hachioji, Tokyo, Japan
| | - Fubito Nakatsu
- Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Camille Hardiman
- Section of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - David Lambright
- Program in Molecular Medicine and Department of Biochemistry & Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Pietro De Camilli
- Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka, Japan
| | - Hiroki Nagai
- Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka, Japan
| | - Craig R. Roy
- Section of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, United States of America
- * E-mail: (AH); (CRR)
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35
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Pirruccello M, Nandez R, Idevall-Hagren O, Alcazar-Roman A, Abriola L, Berwick SA, Lucast L, Morel D, De Camilli P. Identification of inhibitors of inositol 5-phosphatases through multiple screening strategies. ACS Chem Biol 2014; 9:1359-68. [PMID: 24742366 PMCID: PMC4076014 DOI: 10.1021/cb500161z] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
![]()
Phosphoinositides are low abundance
membrane phospholipids that
have key roles in signaling, membrane trafficking, and cytoskeletal
dynamics in all cells. Until recently, strategies for robust and quantitative
development of pharmacological tools for manipulating phosphoinositide
levels have focused selectively on PI(3,4,5)P3 due to the
importance of this lipid in growth factor signaling and cell proliferation.
However, drugs that affect levels of other phosphoinositides have
potential therapeutic applications and will be powerful research tools.
Here, we describe methodology for the high-throughput screening of
small molecule modulators of the inositol 5-phosphatases, which dephosphorylate
PI(4,5)P2 (the precursor for PI(3,4,5)P3) and
PI(3,4,5)P3). We developed three complementary in vitro activity assays, tested hit compounds on a panel
of 5-phosphatases, and monitored efficacy toward various substrates.
Two prominent chemical scaffolds were identified with high nanomolar/low
micromolar activity, with one class showing inhibitory activity toward
all 5-phosphatases tested and the other selective activity toward
OCRL and INPP5B, which are closely related to each other. One highly
soluble OCRL/INPP5B-specific inhibitor shows a direct interaction
with the catalytic domain of INPP5B. The efficacy of this compound
in living cells was validated through its property to enhance actin
nucleation at the cell cortex, a PI(4,5)P2 dependent process,
and to inhibit PI(4,5)P2 dephosphorylation by OCRL (both
overexpressed and endogenous enzyme). The assays and screening strategies
described here are applicable to other phosphoinositide-metabolizing
enzymes, at least several of which have major clinical relevance.
Most importantly, this study identifies the first OCRL/INPP5B specific
inhibitor and provides a platform for the design of more potent inhibitors
of this family of enzymes.
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Affiliation(s)
- Michelle Pirruccello
- Department
of Cell Biology, Howard Hughes Medical Institute and Program in Cellular
Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven Connecticut 06510, United States
| | - Ramiro Nandez
- Department
of Cell Biology, Howard Hughes Medical Institute and Program in Cellular
Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven Connecticut 06510, United States
| | - Olof Idevall-Hagren
- Department
of Cell Biology, Howard Hughes Medical Institute and Program in Cellular
Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven Connecticut 06510, United States
| | - Abel Alcazar-Roman
- Department
of Cell Biology, Howard Hughes Medical Institute and Program in Cellular
Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven Connecticut 06510, United States
| | - Laura Abriola
- Yale
Center for Molecular Discovery, Yale University, West Haven, Connecticut 06516, United States
| | - Shana Alexandra Berwick
- Department
of Cell Biology, Howard Hughes Medical Institute and Program in Cellular
Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven Connecticut 06510, United States
| | - Louise Lucast
- Department
of Cell Biology, Howard Hughes Medical Institute and Program in Cellular
Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven Connecticut 06510, United States
| | - Dayna Morel
- Department
of Cell Biology, Howard Hughes Medical Institute and Program in Cellular
Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven Connecticut 06510, United States
| | - Pietro De Camilli
- Department
of Cell Biology, Howard Hughes Medical Institute and Program in Cellular
Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven Connecticut 06510, United States
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36
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Cossart P, Lebreton A. A trip in the "New Microbiology" with the bacterial pathogen Listeria monocytogenes. FEBS Lett 2014; 588:2437-45. [PMID: 24911203 DOI: 10.1016/j.febslet.2014.05.051] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Revised: 05/23/2014] [Accepted: 05/23/2014] [Indexed: 10/25/2022]
Abstract
Listeria monocytogenes is a food-borne pathogen causing an opportunistic disease called listeriosis. This bacterium invades and replicates in most cell types, due to its multiple strategies to exploit host molecular mechanisms. Research aiming at unravelling Listeria invasion and intracellular lifestyle has led to a number of key discoveries in infection biology, cell biology and also microbiology. In this review, we report on our most recent advances in understanding the intimate crosstalk between the bacterium and its host, resulting from in-depth studies performed over the past five years. We specifically highlight new concepts in RNA-based regulation in bacteria and discuss important findings in cell biology, including a new role for clathrin and an atypical mitochondrial fragmentation mechanism. We also illustrate the notion that bacterial infection regulates host gene expression at the chromatin level, contributing to an emerging field called patho-epigenetics. This review corresponds to the lecture given by one of us (P.C.) on the occasion of the 2014 FEBS|EMBO Woman in Science Award.
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Affiliation(s)
- Pascale Cossart
- Institut Pasteur, Unité des Interactions Bactéries-Cellules, Paris, France; Inserm, U604, Paris, France; INRA, USC2020, Paris, France.
| | - Alice Lebreton
- Institut Pasteur, Unité des Interactions Bactéries-Cellules, Paris, France; Inserm, U604, Paris, France; INRA, USC2020, Paris, France.
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37
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Live-cell imaging of phosphoinositide dynamics and membrane architecture during Legionella infection. mBio 2014; 5:e00839-13. [PMID: 24473127 PMCID: PMC3903275 DOI: 10.1128/mbio.00839-13] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The causative agent of Legionnaires’ disease, Legionella pneumophila, replicates in amoebae and macrophages in a distinct membrane-bound compartment, the Legionella-containing vacuole (LCV). LCV formation is governed by the bacterial Icm/Dot type IV secretion system that translocates ~300 different “effector” proteins into host cells. Some of the translocated effectors anchor to the LCV membrane via phosphoinositide (PI) lipids. Here, we use the soil amoeba Dictyostelium discoideum, producing fluorescent PI probes, to analyze the LCV PI dynamics by live-cell imaging. Upon uptake of wild-type or Icm/Dot-deficient L. pneumophila, PtdIns(3,4,5)P3 transiently accumulated for an average of 40 s on early phagosomes, which acquired PtdIns(3)P within 1 min after uptake. Whereas phagosomes containing ΔicmT mutant bacteria remained decorated with PtdIns(3)P, more than 80% of wild-type LCVs gradually lost this PI within 2 h. The process was accompanied by a major rearrangement of PtdIns(3)P-positive membranes condensing to the cell center. PtdIns(4)P transiently localized to early phagosomes harboring wild-type or ΔicmT L. pneumophila and was cleared within minutes after uptake. During the following 2 h, PtdIns(4)P steadily accumulated only on wild-type LCVs, which maintained a discrete PtdIns(4)P identity spatially separated from calnexin-positive endoplasmic reticulum (ER) for at least 8 h. The separation of PtdIns(4)P-positive and ER membranes was even more pronounced for LCVs harboring ΔsidC-sdcA mutant bacteria defective for ER recruitment, without affecting initial bacterial replication in the pathogen vacuole. These findings elucidate the temporal and spatial dynamics of PI lipids implicated in LCV formation and provide insight into host cell membrane and effector protein interactions. The environmental bacterium Legionella pneumophila is the causative agent of Legionnaires’ pneumonia. The bacteria form in free-living amoebae and mammalian immune cells a replication-permissive compartment, the Legionella-containing vacuole (LCV). To subvert host cell processes, the bacteria secrete the amazing number of ~300 different proteins into host cells. Some of these proteins bind phosphoinositide (PI) lipids to decorate the LCV. PI lipids are crucial factors involved in host cell membrane dynamics and LCV formation. Using Dictyostelium amoebae producing one or two distinct fluorescent probes, we elucidated the dynamic LCV PI pattern in high temporal and spatial resolution. Notably, the endocytic PI lipid PtdIns(3)P was slowly cleared from LCVs, thus incapacitating the host cell’s digestive machinery, while PtdIns(4)P gradually accumulated on the LCV, enabling critical interactions with host organelles. The LCV PI pattern underlies the spatiotemporal configuration of bacterial effector proteins and therefore represents a crucial aspect of LCV formation.
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38
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Toulabi L, Wu X, Cheng Y, Mao Y. Identification and structural characterization of a Legionella phosphoinositide phosphatase. J Biol Chem 2013; 288:24518-27. [PMID: 23843460 PMCID: PMC3750150 DOI: 10.1074/jbc.m113.474239] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Revised: 07/09/2013] [Indexed: 01/17/2023] Open
Abstract
Bacterial pathogen Legionella pneumophila is the causative agent of Legionnaires' disease, which is associated with intracellular replication of the bacteria in macrophages of human innate immune system. Recent studies indicate that pathogenic bacteria can subvert host cell phosphoinositide (PI) metabolism by translocated virulence effectors. However, in which manner Legionella actively exploits PI lipids to benefit its infection is not well characterized. Here we report that L. pneumophila encodes an effector protein, named SidP, that functions as a PI-3-phosphatase specifically hydrolyzing PI(3)P and PI(3,5)P2 in vitro. This activity of SidP rescues the growth phenotype of a yeast strain defective in PI(3)P phosphatase activity. Crystal structure of SidP orthologue from Legionella longbeachae reveals that this unique PI-3-phosphatase is composed of three distinct domains: a large catalytic domain, an appendage domain that is inserted into the N-terminal portion of the catalytic domain, and a C-terminal α-helical domain. SidP has a small catalytic pocket that presumably provides substrate specificity by limiting the accessibility of bulky PIs with multiple phosphate groups. Together, our identification of a unique family of Legionella PI phosphatases highlights a common scheme of exploiting host PI lipids in many intracellular bacterial pathogen infections.
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Affiliation(s)
- Leila Toulabi
- From the Weill Institute for Cell and Molecular Biology and Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14853
| | - Xiaochun Wu
- From the Weill Institute for Cell and Molecular Biology and Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14853
| | - Yanshu Cheng
- From the Weill Institute for Cell and Molecular Biology and Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14853
| | - Yuxin Mao
- From the Weill Institute for Cell and Molecular Biology and Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14853
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39
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Eisenreich W, Heesemann J, Rudel T, Goebel W. Metabolic host responses to infection by intracellular bacterial pathogens. Front Cell Infect Microbiol 2013; 3:24. [PMID: 23847769 PMCID: PMC3705551 DOI: 10.3389/fcimb.2013.00024] [Citation(s) in RCA: 135] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 06/11/2013] [Indexed: 12/12/2022] Open
Abstract
The interaction of bacterial pathogens with mammalian hosts leads to a variety of physiological responses of the interacting partners aimed at an adaptation to the new situation. These responses include multiple metabolic changes in the affected host cells which are most obvious when the pathogen replicates within host cells as in case of intracellular bacterial pathogens. While the pathogen tries to deprive nutrients from the host cell, the host cell in return takes various metabolic countermeasures against the nutrient theft. During this conflicting interaction, the pathogen triggers metabolic host cell responses by means of common cell envelope components and specific virulence-associated factors. These host reactions generally promote replication of the pathogen. There is growing evidence that pathogen-specific factors may interfere in different ways with the complex regulatory network that controls the carbon and nitrogen metabolism of mammalian cells. The host cell defense answers include general metabolic reactions, like the generation of oxygen- and/or nitrogen-reactive species, and more specific measures aimed to prevent access to essential nutrients for the respective pathogen. Accurate results on metabolic host cell responses are often hampered by the use of cancer cell lines that already exhibit various de-regulated reactions in the primary carbon metabolism. Hence, there is an urgent need for cellular models that more closely reflect the in vivo infection conditions. The exact knowledge of the metabolic host cell responses may provide new interesting concepts for antibacterial therapies.
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Affiliation(s)
- Wolfgang Eisenreich
- Lehrstuhl für Biochemie, Center of Isotopologue Profiling, Technische Universität München Garching, Germany
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40
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Abstract
Phosphoinositides (PIs) make up only a small fraction of cellular phospholipids, yet they control almost all aspects of a cell's life and death. These lipids gained tremendous research interest as plasma membrane signaling molecules when discovered in the 1970s and 1980s. Research in the last 15 years has added a wide range of biological processes regulated by PIs, turning these lipids into one of the most universal signaling entities in eukaryotic cells. PIs control organelle biology by regulating vesicular trafficking, but they also modulate lipid distribution and metabolism via their close relationship with lipid transfer proteins. PIs regulate ion channels, pumps, and transporters and control both endocytic and exocytic processes. The nuclear phosphoinositides have grown from being an epiphenomenon to a research area of its own. As expected from such pleiotropic regulators, derangements of phosphoinositide metabolism are responsible for a number of human diseases ranging from rare genetic disorders to the most common ones such as cancer, obesity, and diabetes. Moreover, it is increasingly evident that a number of infectious agents hijack the PI regulatory systems of host cells for their intracellular movements, replication, and assembly. As a result, PI converting enzymes began to be noticed by pharmaceutical companies as potential therapeutic targets. This review is an attempt to give an overview of this enormous research field focusing on major developments in diverse areas of basic science linked to cellular physiology and disease.
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Affiliation(s)
- Tamas Balla
- Section on Molecular Signal Transduction, Program for Developmental Neuroscience, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA.
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41
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Exploitation of eukaryotic subcellular targeting mechanisms by bacterial effectors. Nat Rev Microbiol 2013; 11:316-26. [PMID: 23588250 DOI: 10.1038/nrmicro3009] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Several bacterial species have evolved specialized secretion systems to deliver bacterial effector proteins into eukaryotic cells. These effectors have the capacity to modulate host cell pathways in order to promote bacterial survival and replication. The spatial and temporal context in which the effectors exert their biochemical activities is crucial for their function. To fully understand effector function in the context of infection, we need to understand the mechanisms that lead to the precise subcellular localization of effectors following their delivery into host cells. Recent studies have shown that bacterial effectors exploit host cell machinery to accurately target their biochemical activities within the host cell.
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Phosphatidylinositol 4,5-bisphosphate is a novel coactivator of the Pseudomonas aeruginosa cytotoxin ExoU. Infect Immun 2013; 81:2873-81. [PMID: 23716613 DOI: 10.1128/iai.00414-13] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
ExoU is a potent phospholipase A2 effector protein secreted by the type III secretion system of Pseudomonas aeruginosa. By cleaving plasma membrane phospholipids, it causes rapid lysis of eukaryotic cells. However, ExoU does not exhibit activity on its own but instead requires eukaryotic cell cofactors for activation. Ubiquitin and ubiquitinated proteins have been shown to activate ExoU, but previous work suggested that other cofactors are also involved. In this study, we demonstrate that phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] is another important coactivator of ExoU. PI(4,5)P2 works synergistically with ubiquitin to greatly enhance the phospholipase A2 activity of ExoU. Distinct residues of ExoU were critical for activation by PI(4,5)P2 and by ubiquitin, indicating that these factors activate ExoU by discrete mechanisms. In support of the biological relevance of PI(4,5)P2 coactivation, a yeast mutant with reduced PI(4,5)P2 levels was less susceptible to the cytotoxic activity of ExoU. Together, these findings further elaborate the molecular mechanism of ExoU.
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43
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Minnaard J, Rolny IS, Pérez PF. Interaction between Bacillus cereus and cultured human enterocytes: effect of calcium, cell differentiation, and bacterial extracellular factors. J Food Prot 2013; 76:820-6. [PMID: 23643123 DOI: 10.4315/0362-028x.jfp-12-294] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Bacillus cereus interaction with cultured human enterocytes and the signaling pathways responsible for the biological effects of the infection were investigated. Results demonstrate that calcium depletion increases the ability of strains T1 and 2 to invade cells. Bacteria associated in greater extent to undifferentiated enterocytes and extracellular factors from strain 2 increased its own association and invasion. Inhibitors of signaling pathways related to phosphorylated lipids (U73122 and wortmannin) were able to significantly reduce cytoskeleton disruption induced by B. cereus infection. Adhesion of strain T1 decreased in the presence of U73122 and of wortmannin, as well as when those inhibitors were used together. In contrast, invasion values were diminished only by U73122. Results show that different factors are involved in the interaction between B. cereus and cultured human enterocytes. Following infection, disruption of the cytoskeleton could facilitate invasion of the eukaryotic cells.
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Affiliation(s)
- Jessica Minnaard
- Centro de Investigación y Desarrollo en Criotecnología de Alimentos (Consejo Nacional de Investigaciones Científicas y Técnicas [CONICET], La Plata), Calle 47 y 116-B1900AJI, La Plata, Argentina.
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44
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Hsu F, Mao Y. The Sac domain-containing phosphoinositide phosphatases: structure, function, and disease. ACTA ACUST UNITED AC 2013; 8:395-407. [PMID: 24860601 DOI: 10.1007/s11515-013-1258-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Phosphoinositides (PIs) have long been known to have an essential role in cell physiology. Their intracellular localization and concentration must be tightly regulated for their proper function. This spatial and temporal regulation is achieved by a large number of PI kinases and phosphatases that are present throughout eukaryotic species. One family of these enzymes contains a conserved PI phosphatase domain termed Sac. Although the Sac domain is homologous among different Sac domain-containing proteins, all appear to exhibit varied substrate specificity and subcellular localization. Dysfunctions in several members of this family are implicated in a range of human diseases such as cardiac hypertrophy, bipolar disorder, Down's syndrome, Charcot-Marie-Tooth disease (CMT) and Amyotrophic Lateral Sclerosis (ALS). In plant, several Sac domain-containing proteins have been implicated in the stress response, chloroplast function and polarized secretion. In this review, we focus on recent findings in the family of Sac domain-containing PI phosphatases in yeast, mammal and plant, including the structural analysis into the mechanism of enzymatic activity, cellular functions, and their roles in disease pathophysiology.
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Affiliation(s)
- FoSheng Hsu
- Weill Institute for Cell and Molecular Biology and Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Yuxin Mao
- Weill Institute for Cell and Molecular Biology and Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
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45
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Weber S, Dolinsky S, Hilbi H. Interactions of legionella effector proteins with host phosphoinositide lipids. Methods Mol Biol 2013; 954:367-80. [PMID: 23150409 DOI: 10.1007/978-1-62703-161-5_23] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
By means of the Icm/Dot type IV secretion system Legionella pneumophila translocates several effector proteins into host cells, where they anchor to the cytoplasmic face of the LCV membrane by binding to phosphoinositide (PI) lipids. Thus, phosphatidylinositol-4-phosphate anchors the effector proteins SidC and SidM, which promote the interaction of LCVs with the ER and the secretory vesicle trafficking -pathway. In this chapter, we describe protocols to (1) identify PI-binding proteins in Legionella lysates using PI-beads, (2) determine PI-binding specificities and affinities of recombinant Legionella effector proteins by protein-lipid overlays, and (3) use Legionella effectors to identify cellular PI lipids.
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Affiliation(s)
- Stephen Weber
- Max von Pettenkofer Institute, Ludwig-Maximilians University, Munich, Germany
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46
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Haneburger I, Hilbi H. Phosphoinositide lipids and the Legionella pathogen vacuole. Curr Top Microbiol Immunol 2013; 376:155-73. [PMID: 23918172 DOI: 10.1007/82_2013_341] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Subversion of vesicle trafficking is vital for intracellular survival of Legionella pneumophila within host cells. L. pneumophila produces several type IV-translocated effector proteins that modify components of the phagosomal membrane, in particular the phosphoinositide (PI) lipids. Within eukaryotic cells PIs co-define subcellular compartments and membrane dynamics. The generation, half-life, and localization of PI lipids are not only tightly regulated by the host cell, but also targeted and modulated by a number of L. pneumophila effectors. These effectors either anchor to PIs, directly modify the lipids, or recruit PI-metabolizing enzymes to the LCV membrane. Together, PI-subverting L. pneumophila effectors act jointly to promote the formation of a replication-permissive niche inside the host.
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Affiliation(s)
- Ina Haneburger
- Medical Faculty, Max von Pettenkofer Institute, Ludwig-Maximilians University, Munich Pettenkoferstrasse 9a, 80336, Munich, Germany
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47
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Structural basis for substrate recognition by a unique Legionella phosphoinositide phosphatase. Proc Natl Acad Sci U S A 2012; 109:13567-72. [PMID: 22872863 DOI: 10.1073/pnas.1207903109] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Legionella pneumophila is an opportunistic intracellular pathogen that causes sporadic and epidemic cases of Legionnaires' disease. Emerging data suggest that Legionella infection involves the subversion of host phosphoinositide (PI) metabolism. However, how this bacterium actively manipulates PI lipids to benefit its infection is still an enigma. Here, we report that the L. pneumophila virulence factor SidF is a phosphatidylinositol polyphosphate 3-phosphatase that specifically hydrolyzes the D3 phosphate of PI(3,4)P(2) and PI(3,4,5)P(3). This activity is necessary for anchoring of PI(4)P-binding effectors to bacterial phagosomes. Crystal structures of SidF and its complex with its substrate PI(3,4)P(2) reveal striking conformational rearrangement of residues at the catalytic site to form a cationic pocket that specifically accommodates the D4 phosphate group of the substrate. Thus, our findings unveil a unique Legionella PI phosphatase essential for the establishment of lipid identity of bacterial phagosomes.
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48
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WIPI-1 Positive Autophagosome-Like Vesicles Entrap Pathogenic Staphylococcus aureus for Lysosomal Degradation. Int J Cell Biol 2012; 2012:179207. [PMID: 22829830 PMCID: PMC3399381 DOI: 10.1155/2012/179207] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Revised: 01/31/2012] [Accepted: 02/06/2012] [Indexed: 12/27/2022] Open
Abstract
Invading pathogens provoke the autophagic machinery and, in a process termed xenophagy, the host cell survives because autophagy is employed as a safeguard for pathogens that escaped phagosomes. However, some pathogens can manipulate the autophagic pathway and replicate within the niche of generated autophagosome-like vesicles. By automated fluorescence-based high content analyses, we demonstrate that Staphylococcus aureus strains (USA300, HG001, SA113) stimulate autophagy and become entrapped in intracellular PtdIns(3)P-enriched vesicles that are decorated with human WIPI-1, an essential PtdIns(3)P effector of canonical autophagy and membrane protein of both phagophores and autophagosomes. Further, agr-positive S. aureus (USA300, HG001) strains were more efficiently entrapped in WIPI-1 positive autophagosome-like vesicles when compared to agr-negative cells (SA113). By confocal and electron microscopy we provide evidence that single- and multiple-Staphylococci entrapped undergo cell division. Moreover, the number of WIPI-1 positive autophagosome-like vesicles entrapping Staphylococci significantly increased upon (i) lysosomal inhibition by bafilomycin A(1) and (ii) blocking PIKfyve-mediated PtdIns(3,5)P(2) generation by YM201636. In summary, our results provide evidence that the PtdIns(3)P effector function of WIPI-1 is utilized during xenophagy of Staphylococcus aureus. We suggest that invading S. aureus cells become entrapped in autophagosome-like WIPI-1 positive vesicles targeted for lysosomal degradation in nonprofessional host cells.
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López-Gómez A, Cano V, Moranta D, Morey P, García Del Portillo F, Bengoechea JA, Garmendia J. Host cell kinases, α5 and β1 integrins, and Rac1 signalling on the microtubule cytoskeleton are important for non-typable Haemophilus influenzae invasion of respiratory epithelial cells. MICROBIOLOGY-SGM 2012; 158:2384-2398. [PMID: 22723286 DOI: 10.1099/mic.0.059972-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Non-typable Haemophilus influenzae (NTHi) is a common commensal of the human nasopharynx, but causes opportunistic infection when the respiratory tract is compromised by infection or disease. The ability of NTHi to invade epithelial cells has been described, but the underlying molecular mechanisms are poorly characterized. We previously determined that NTHi promotes phosphorylation of the serine-threonine kinase Akt in A549 human lung epithelial cells, and that Akt phosphorylation and NTHi cell invasion are prevented by inhibition of phosphoinositide 3-kinase (PI3K). Because PI3K-Akt signalling is associated with several host cell networks, the purpose of the current study was to identify eukaryotic molecules important for NTHi epithelial invasion. We found that inhibition of Akt activity reduced NTHi internalization; differently, bacterial entry was increased by phospholipase Cγ1 inhibition but was not affected by protein kinase inhibition. We also found that α5 and β1 integrins, and the tyrosine kinases focal adhesion kinase and Src, are important for NTHi A549 cell invasion. NTHi internalization was shown to be favoured by activation of Rac1 guanosine triphosphatase (GTPase), together with the guanine nucleotide exchange factor Vav2 and the effector Pak1. Also, Pak1 might be associated with inactivation of the microtubule destabilizing agent Op18/stathmin, to facilitate microtubule polymerization and NTHi entry. Conversely, inhibition of RhoA GTPase and its effector ROCK increased the number of internalized bacteria. Src and Rac1 were found to be important for NTHi-triggered Akt phosphorylation. An increase in host cyclic AMP reduced bacterial entry, which was linked to protein kinase A. These findings suggest that NTHi finely manipulates host signalling molecules to invade respiratory epithelial cells.
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Affiliation(s)
- Antonio López-Gómez
- Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Bunyola, Spain.,Laboratory Microbial Pathogenesis, Fundación Investigación Sanitaria Illes Balears, Bunyola, Spain
| | - Victoria Cano
- Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Bunyola, Spain.,Laboratory Microbial Pathogenesis, Fundación Investigación Sanitaria Illes Balears, Bunyola, Spain
| | - David Moranta
- Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Bunyola, Spain.,Laboratory Microbial Pathogenesis, Fundación Investigación Sanitaria Illes Balears, Bunyola, Spain
| | - Pau Morey
- Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Bunyola, Spain.,Laboratory Microbial Pathogenesis, Fundación Investigación Sanitaria Illes Balears, Bunyola, Spain
| | | | - José Antonio Bengoechea
- Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Bunyola, Spain.,Laboratory Microbial Pathogenesis, Fundación Investigación Sanitaria Illes Balears, Bunyola, Spain
| | - Junkal Garmendia
- Instituto de Agrobiotecnología, CSIC-Universidad Pública de Navarra-Gobierno de Navarra, Mutilva, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Bunyola, Spain.,Laboratory Microbial Pathogenesis, Fundación Investigación Sanitaria Illes Balears, Bunyola, Spain
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50
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Al-Quadan T, Price CT, Abu Kwaik Y. Exploitation of evolutionarily conserved amoeba and mammalian processes by Legionella. Trends Microbiol 2012; 20:299-306. [PMID: 22494803 DOI: 10.1016/j.tim.2012.03.005] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2011] [Revised: 02/29/2012] [Accepted: 03/13/2012] [Indexed: 01/09/2023]
Abstract
Legionella pneumophila proliferates within various protists and metazoan cells, where a cadre of ∼300 effectors is injected into the host cell by the defect in organelle trafficking/intracellular multiplication (Dot/Icm) type IVB translocation system. Interkingdom horizontal gene transfer of genes of protists and their subsequent convergent evolution to become translocated effectors has probably enabled L. pneumophila to adapt to the intracellular life within various protists and metazoan cells through exploitation of evolutionarily eukaryotic processes, such as endoplasmic reticulum-to-Golgi vesicle traffic, phosphoinositol metabolism, AMPylation, deAMPylation, prenylation, polyubiquitination, proteasomal degradation and cytosolic amino- and oligo-peptidases. This is highlighted by the ankyrin B (AnkB) F-box effector that exploits multiple conserved eukaryotic machineries to generate high levels of free amino acids as sources of carbon and energy essential for intracellular proliferation in protists and metazoan cells and for manifestation of pulmonary disease in mammals.
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Affiliation(s)
- Tasneem Al-Quadan
- Department of Microbiology and Immunology, College of Medicine, University of Louisville, Louisville, KY 40292, USA
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