1
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Prado LG, Camara NOS, Barbosa AS. Cell lipid biology in infections: an overview. Front Cell Infect Microbiol 2023; 13:1148383. [PMID: 37868347 PMCID: PMC10587689 DOI: 10.3389/fcimb.2023.1148383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 09/22/2023] [Indexed: 10/24/2023] Open
Abstract
Lipids are a big family of molecules with a vast number of functions in the cell membranes, within the cytoplasm, and extracellularly. Lipid droplets (LDs) are the most common storage organelles and are present in almost every tissue type in the body. They also have structural functions serving as building blocks of cellular membranes and may be precursors of other molecules such as hormones, and lipoproteins, and as messengers in signal transduction. Fatty acids (FAs), such as sterol esters and triacylglycerols, are stored in LDs and are used in β-oxidation as fuel for tricarboxylic acid cycle (TCA) and adenosine triphosphate (ATP) generation. FA uptake and entrance in the cytoplasm are mediated by membrane receptors. After a cytoplasmic round of α- and β-oxidation, FAs are guided into the mitochondrial matrix by the L-carnitine shuttle system, where they are fully metabolized, and enter the TCA cycle. Pathogen infections may lead to impaired lipid metabolism, usage of membrane phospholipids, and LD accumulation in the cytoplasm of infected cells. Otherwise, bacterial pathogens may use lipid metabolism as a carbon source, thus altering the reactions and leading to cellular and organelles malfunctioning. This review aims to describe cellular lipid metabolism and alterations that occur upon infections.
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Affiliation(s)
- Luan Gavião Prado
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, Brazil
- Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
| | - Niels Olsen Saraiva Camara
- Laboratório de Imunobiologia de Transplantes, Departamento de Imunologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
- Disciplina de Nefrologia, Departamento de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
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2
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Jouault A, Saliba AM, Touqui L. Modulation of the immune response by the Pseudomonas aeruginosa type-III secretion system. Front Cell Infect Microbiol 2022; 12:1064010. [PMID: 36519135 PMCID: PMC9742435 DOI: 10.3389/fcimb.2022.1064010] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 11/15/2022] [Indexed: 11/29/2022] Open
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen that can cause critical cellular damage and subvert the immune response to promote its survival. Among the numerous virulence factors of P. aeruginosa, the type III secretion system (T3SS) is involved in host cell pathogenicity. Using a needle-like structure, T3SS detects eukaryotic cells and injects toxins directly into their cytosol, thus highlighting its ability to interfere with the host immune response. In this mini-review, we discuss how the T3SS and bacterial effectors secreted by this pathway not only activate the immune response but can also manipulate it to promote the establishment of P. aeruginosa infections.
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Affiliation(s)
- Albane Jouault
- Mucoviscidose: Phénotypique et Phénogénomique, Centre de Recherche Saint-Antoine, Sorbonne Universités, UPMC Univ Paris 06, INSERM, Paris, France,Département Santé Globale, Mucoviscidose et Bronchopathie Chroniques, Institut Pasteur, Paris, France,*Correspondence: Albane Jouault,
| | - Alessandra Mattos Saliba
- Department of Microbiology, Immunology and Parasitology, Faculty of Medical Sciences, Rio de Janeiro State University, Rio de Janeiro, Brazil
| | - Lhousseine Touqui
- Mucoviscidose: Phénotypique et Phénogénomique, Centre de Recherche Saint-Antoine, Sorbonne Universités, UPMC Univ Paris 06, INSERM, Paris, France,Département Santé Globale, Mucoviscidose et Bronchopathie Chroniques, Institut Pasteur, Paris, France
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3
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Constantino-Teles P, Jouault A, Touqui L, Saliba AM. Role of Host and Bacterial Lipids in Pseudomonas aeruginosa Respiratory Infections. Front Immunol 2022; 13:931027. [PMID: 35860265 PMCID: PMC9289105 DOI: 10.3389/fimmu.2022.931027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 06/07/2022] [Indexed: 11/13/2022] Open
Abstract
The opportunistic pathogen Pseudomonas aeruginosa is one of the most common agents of respiratory infections and has been associated with high morbidity and mortality rates. The ability of P. aeruginosa to cause severe respiratory infections results from the coordinated action of a variety of virulence factors that promote bacterial persistence in the lungs. Several of these P. aeruginosa virulence mechanisms are mediated by bacterial lipids, mainly lipopolysaccharide, rhamnolipid, and outer membrane vesicles. Other mechanisms arise from the activity of P. aeruginosa enzymes, particularly ExoU, phospholipase C, and lipoxygenase A, which modulate host lipid signaling pathways. Moreover, host phospholipases, such as cPLA2α and sPLA2, are also activated during the infectious process and play important roles in P. aeruginosa pathogenesis. These mechanisms affect key points of the P. aeruginosa-host interaction, such as: i) biofilm formation that contributes to bacterial colonization and survival, ii) invasion of tissue barriers that allows bacterial dissemination, iii) modulation of inflammatory responses, and iv) escape from host defenses. In this mini-review, we present the lipid-based mechanism that interferes with the establishment of P. aeruginosa in the lungs and discuss how bacterial and host lipids can impact the outcome of P. aeruginosa respiratory infections.
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Affiliation(s)
- Pamella Constantino-Teles
- Department of Microbiology, Immunology and Parasitology, Faculty of Medical Sciences, Rio de Janeiro State University, Rio de Janeiro, Brazil
| | - Albane Jouault
- Sorbonne Université, Centre de Recherche Saint-Antoine, Inserm, Institut Pasteur, Mucoviscidose et Bronchopathies Chroniques, Département Santé Globale, Paris, France
| | - Lhousseine Touqui
- Sorbonne Université, Centre de Recherche Saint-Antoine, Inserm, Institut Pasteur, Mucoviscidose et Bronchopathies Chroniques, Département Santé Globale, Paris, France
| | - Alessandra Mattos Saliba
- Department of Microbiology, Immunology and Parasitology, Faculty of Medical Sciences, Rio de Janeiro State University, Rio de Janeiro, Brazil
- *Correspondence: Alessandra Mattos Saliba,
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4
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Peres-Emidio EC, Freitas GJC, Costa MC, Gouveia-Eufrasio L, Silva LMV, Santos APN, Carmo PHF, Brito CB, Arifa RDN, Bastos RW, Ribeiro NQ, Oliveira LVN, Silva MF, Paixão TA, Saliba AM, Fagundes CT, Souza DG, Santos DA. Pseudomonas aeruginosa Infection Modulates the Immune Response and Increases Mice Resistance to Cryptococcus gattii. Front Cell Infect Microbiol 2022; 12:811474. [PMID: 35548467 PMCID: PMC9083911 DOI: 10.3389/fcimb.2022.811474] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 03/22/2022] [Indexed: 11/30/2022] Open
Abstract
Cryptococcosis is an invasive mycosis caused by Cryptococcus spp. that affects the lungs and the central nervous system (CNS). Due to the severity of the disease, it may occur concomitantly with other pathogens, as a coinfection. Pseudomonas aeruginosa (Pa), an opportunistic pathogen, can also cause pneumonia. In this work, we studied the interaction of C. gattii (Cg) and Pa, both in vitro and in vivo. Pa reduced growth of Cg by the secretion of inhibitory molecules in vitro. Macrophages previously stimulated with Pa presented increased fungicidal activity. In vivo, previous Pa infection reduced morbidity and delayed the lethality due to cryptococcosis. This phenotype was correlated with the decreased fungal burden in the lungs and brain, showing a delay of Cg translocation to the CNS. Also, there was increased production of IL-1β, CXCL-1, and IL-10, together with the influx of iNOS-positive macrophages and neutrophils to the lungs. Altogether, Pa turned the lung into a hostile environment to the growth of a secondary pathogen, making it difficult for the fungus to translocate to the CNS. Further, iNOS inhibition reverted the Pa protective phenotype, suggesting its
important role in the coinfection. Altogether, the primary Pa infection leads to balanced pro-inflammatory and anti-inflammatory responses during Cg infection. This response provided better control of cryptococcosis and was decisive for the mild evolution of the disease and prolonged survival of coinfected mice in a mechanism dependent on iNOS.
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Affiliation(s)
- Eluzia C. Peres-Emidio
- Departamento de Microbiologia/Laboratorio de Micologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Gustavo J. C. Freitas
- Departamento de Microbiologia/Laboratorio de Micologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Marliete C. Costa
- Departamento de Microbiologia/Laboratorio de Micologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Ludmila Gouveia-Eufrasio
- Departamento de Microbiologia/Laboratorio de Micologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Lívia M. V. Silva
- Departamento de Microbiologia/Laboratorio de Micologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Anderson P. N. Santos
- Departamento de Microbiologia/Laboratorio de Micologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Paulo H. F. Carmo
- Departamento de Microbiologia/Laboratorio de Micologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Camila B. Brito
- Departamento de Microbiologia/Laboratorio de Interação Microorganismo-Hospedeiro, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Raquel D. N. Arifa
- Departamento de Microbiologia/Laboratorio de Interação Microorganismo-Hospedeiro, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Rafael W. Bastos
- Faculdade de Ciencias Farmaceuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
- Centro de Biociencias, Universidade Federal do Rio Grande do Norte, Natal, Brazil
| | - Noelly Q. Ribeiro
- Departamento de Microbiologia/Laboratorio de Micologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Lorena V. N. Oliveira
- Departamento de Microbiologia/Laboratorio de Micologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Monique F. Silva
- Departamento de Patologia/Laboratorio de Patologia Celular e Molecular, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Tatiane A. Paixão
- Departamento de Patologia/Laboratorio de Patologia Celular e Molecular, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Alessandra M. Saliba
- Departamento de Microbiologia e Imunologia, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Caio T. Fagundes
- Departamento de Microbiologia/Laboratorio de Interação Microorganismo-Hospedeiro, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Daniele G. Souza
- Departamento de Microbiologia/Laboratorio de Interação Microorganismo-Hospedeiro, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Daniel A. Santos
- Departamento de Microbiologia/Laboratorio de Micologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
- *Correspondence: Daniel A. Santos, ;
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5
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Weiler AJ, Spitz O, Gudzuhn M, Schott-Verdugo SN, Kamel M, Thiele B, Streit WR, Kedrov A, Schmitt L, Gohlke H, Kovacic F. A phospholipase B from Pseudomonas aeruginosa with activity towards endogenous phospholipids affects biofilm assembly. Biochim Biophys Acta Mol Cell Biol Lipids 2022; 1867:159101. [DOI: 10.1016/j.bbalip.2021.159101] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Revised: 12/09/2021] [Accepted: 12/15/2021] [Indexed: 11/29/2022]
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6
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CrkII/Abl phosphorylation cascade is critical for NLRC4 inflammasome activity and is blocked by Pseudomonas aeruginosa ExoT. Nat Commun 2022; 13:1295. [PMID: 35277504 PMCID: PMC8917168 DOI: 10.1038/s41467-022-28967-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 02/22/2022] [Indexed: 11/17/2022] Open
Abstract
Type 3 Secretion System (T3SS) is a highly conserved virulence structure that plays an essential role in the pathogenesis of many Gram-negative pathogenic bacteria, including Pseudomonas aeruginosa. Exotoxin T (ExoT) is the only T3SS effector protein that is expressed in all T3SS-expressing P. aeruginosa strains. Here we show that T3SS recognition leads to a rapid phosphorylation cascade involving Abl / PKCδ / NLRC4, which results in NLRC4 inflammasome activation, culminating in inflammatory responses that limit P. aeruginosa infection in wounds. We further show that ExoT functions as the main anti-inflammatory agent for P. aeruginosa in that it blocks the phosphorylation cascade through Abl / PKCδ / NLRC4 by targeting CrkII, which we further demonstrate to be important for Abl transactivation and NLRC4 inflammasome activation in response to T3SS and P. aeruginosa infection. Pseudomonas aeruginosa secretes the toxin ExoT, which is important for pathogenesis. Here, the authors show that ExoT inhibits NLRC4-dependent inflammatory responses during wound infection.
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7
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Dar HH, Epperly MW, Tyurin VA, Amoscato AA, Anthonymuthu TS, Souryavong AB, Kapralov AA, Shurin GV, Samovich SN, St. Croix CM, Watkins SC, Wenzel SE, Mallampalli RK, Greenberger JS, Bayır H, Kagan VE, Tyurina YY. P. aeruginosa augments irradiation injury via 15-lipoxygenase-catalyzed generation of 15-HpETE-PE and induction of theft-ferroptosis. JCI Insight 2022; 7:156013. [PMID: 35041620 PMCID: PMC8876480 DOI: 10.1172/jci.insight.156013] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 01/13/2022] [Indexed: 01/14/2023] Open
Abstract
Total body irradiation (TBI) targets sensitive bone marrow hematopoietic cells and gut epithelial cells, causing their death and inducing a state of immunodeficiency combined with intestinal dysbiosis and nonproductive immune responses. We found enhanced Pseudomonas aeruginosa (PAO1) colonization of the gut leading to host cell death and strikingly decreased survival of irradiated mice. The PAO1-driven pathogenic mechanism includes theft-ferroptosis realized via (a) curbing of the host antiferroptotic system, GSH/GPx4, and (b) employing bacterial 15-lipoxygenase to generate proferroptotic signal - 15-hydroperoxy-arachidonoyl-PE (15-HpETE-PE) - in the intestines of irradiated and PAO1-infected mice. Global redox phospholipidomics of the ileum revealed that lysophospholipids and oxidized phospholipids, particularly oxidized phosphatidylethanolamine (PEox), represented the major factors that contributed to the pathogenic changes induced by total body irradiation and infection by PAO1. A lipoxygenase inhibitor, baicalein, significantly attenuated animal lethality, PAO1 colonization, intestinal epithelial cell death, and generation of ferroptotic PEox signals. Opportunistic PAO1 mechanisms included stimulation of the antiinflammatory lipoxin A4, production and suppression of the proinflammatory hepoxilin A3, and leukotriene B4. Unearthing complex PAO1 pathogenic/virulence mechanisms, including effects on the host anti/proinflammatory responses, lipid metabolism, and ferroptotic cell death, points toward potentially new therapeutic and radiomitigative targets.
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Affiliation(s)
- Haider H. Dar
- Department of Environmental and Occupational Health and Center for Free Radical and Antioxidant Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Michael W. Epperly
- Department of Radiation Oncology, UPMC Hillman Cancer Center, Pittsburgh, Pennsylvania, USA
| | - Vladimir A. Tyurin
- Department of Environmental and Occupational Health and Center for Free Radical and Antioxidant Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Andrew A. Amoscato
- Department of Environmental and Occupational Health and Center for Free Radical and Antioxidant Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Tamil S. Anthonymuthu
- Department of Environmental and Occupational Health and Center for Free Radical and Antioxidant Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.,Department of Critical Care Medicine, Safar Center for Resuscitation Research, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Austin B. Souryavong
- Department of Environmental and Occupational Health and Center for Free Radical and Antioxidant Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Alexander A. Kapralov
- Department of Environmental and Occupational Health and Center for Free Radical and Antioxidant Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Galina V. Shurin
- Department of Environmental and Occupational Health and Center for Free Radical and Antioxidant Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Svetlana N. Samovich
- Department of Environmental and Occupational Health and Center for Free Radical and Antioxidant Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | | | - Simon C. Watkins
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Sally E. Wenzel
- Department of Environmental and Occupational Health and Center for Free Radical and Antioxidant Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Rama K. Mallampalli
- Department of Internal Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Joel S. Greenberger
- Department of Radiation Oncology, UPMC Hillman Cancer Center, Pittsburgh, Pennsylvania, USA
| | - Hülya Bayır
- Department of Environmental and Occupational Health and Center for Free Radical and Antioxidant Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.,Department of Critical Care Medicine, Safar Center for Resuscitation Research, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA.,Children’s Neuroscience Institute, Children’s Hospital of Pittsburgh, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Valerian E. Kagan
- Department of Environmental and Occupational Health and Center for Free Radical and Antioxidant Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.,Institute for Regenerative Medicine, I.M. Sechenov First Moscow State Medical University, Moscow, Russia.,Departments of Pharmacology and Chemical Biology, Chemistry, Radiation Oncology, University of Pittsburgh, Pennsylvania, USA
| | - Yulia Y. Tyurina
- Department of Environmental and Occupational Health and Center for Free Radical and Antioxidant Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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8
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Hardy KS, Tuckey AN, Renema P, Patel M, Al-Mehdi AB, Spadafora D, Schlumpf CA, Barrington RA, Alexeyev MF, Stevens T, Pittet JF, Wagener BM, Simmons JD, Alvarez DF, Audia JP. ExoU Induces Lung Endothelial Cell Damage and Activates Pro-Inflammatory Caspase-1 during Pseudomonas aeruginosa Infection. Toxins (Basel) 2022; 14:toxins14020152. [PMID: 35202178 PMCID: PMC8878379 DOI: 10.3390/toxins14020152] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 02/07/2022] [Accepted: 02/11/2022] [Indexed: 12/24/2022] Open
Abstract
The Gram-negative, opportunistic pathogen Pseudomonas aeruginosa utilizes a type III secretion system to inject exoenzyme effectors into a target host cell. Of the four best-studied exoenzymes, ExoU causes rapid cell damage and death. ExoU is a phospholipase A2 (PLA2) that hydrolyses host cell membranes, and P. aeruginosa strains expressing ExoU are associated with poor outcomes in critically ill patients with pneumonia. While the effects of ExoU on lung epithelial and immune cells are well studied, a role for ExoU in disrupting lung endothelial cell function has only recently emerged. Lung endothelial cells maintain a barrier to fluid and protein flux into tissue and airspaces and regulate inflammation. Herein, we describe a pulmonary microvascular endothelial cell (PMVEC) culture infection model to examine the effects of ExoU. Using characterized P. aeruginosa strains and primary clinical isolates, we show that strains expressing ExoU disrupt PMVEC barrier function by causing substantial PMVEC damage and lysis, in a PLA2-dependent manner. In addition, we show that strains expressing ExoU activate the pro-inflammatory caspase-1, in a PLA2-dependent manner. Considering the important roles for mitochondria and oxidative stress in regulating inflammatory responses, we next examined the effects of ExoU on reactive oxygen species production. Infection of PMVECs with P. aeruginosa strains expressing ExoU triggered a robust oxidative stress compared to strains expressing other exoenzyme effectors. We also provide evidence that, intriguingly, ExoU PLA2 activity was detectable in mitochondria and mitochondria-associated membrane fractions isolated from P. aeruginosa-infected PMVECs. Interestingly, ExoU-mediated activation of caspase-1 was partially inhibited by reactive oxygen species scavengers. Together, these data suggest ExoU exerts pleiotropic effects on PMVEC function during P. aeruginosa infection that may inhibit endothelial barrier and inflammatory functions.
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Affiliation(s)
- Kierra S. Hardy
- Department of Microbiology and Immunology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA; (K.S.H.); (A.N.T.); (C.A.S.); (R.A.B.)
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA; (P.R.); (M.P.); (A.-B.A.-M.); (M.F.A.); (T.S.); (J.D.S.); (D.F.A.)
- Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Amanda N. Tuckey
- Department of Microbiology and Immunology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA; (K.S.H.); (A.N.T.); (C.A.S.); (R.A.B.)
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA; (P.R.); (M.P.); (A.-B.A.-M.); (M.F.A.); (T.S.); (J.D.S.); (D.F.A.)
| | - Phoibe Renema
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA; (P.R.); (M.P.); (A.-B.A.-M.); (M.F.A.); (T.S.); (J.D.S.); (D.F.A.)
- Department of Physiology and Cell Biology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA
- Department of Biomedical Sciences, College of Allied Health, University of South Alabama Mobile, Mobile, AL 36688, USA
| | - Mita Patel
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA; (P.R.); (M.P.); (A.-B.A.-M.); (M.F.A.); (T.S.); (J.D.S.); (D.F.A.)
- Department of Pharmacology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA
| | - Abu-Bakr Al-Mehdi
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA; (P.R.); (M.P.); (A.-B.A.-M.); (M.F.A.); (T.S.); (J.D.S.); (D.F.A.)
- Department of Pharmacology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA
| | - Domenico Spadafora
- Flow Cytometry Core Lab, College of Medicine, University of South Alabama, Mobile, AL 36688, USA;
| | - Cody A. Schlumpf
- Department of Microbiology and Immunology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA; (K.S.H.); (A.N.T.); (C.A.S.); (R.A.B.)
| | - Robert A. Barrington
- Department of Microbiology and Immunology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA; (K.S.H.); (A.N.T.); (C.A.S.); (R.A.B.)
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA; (P.R.); (M.P.); (A.-B.A.-M.); (M.F.A.); (T.S.); (J.D.S.); (D.F.A.)
- Flow Cytometry Core Lab, College of Medicine, University of South Alabama, Mobile, AL 36688, USA;
| | - Mikhail F. Alexeyev
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA; (P.R.); (M.P.); (A.-B.A.-M.); (M.F.A.); (T.S.); (J.D.S.); (D.F.A.)
- Department of Physiology and Cell Biology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA
| | - Troy Stevens
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA; (P.R.); (M.P.); (A.-B.A.-M.); (M.F.A.); (T.S.); (J.D.S.); (D.F.A.)
- Department of Physiology and Cell Biology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA
| | - Jean-Francois Pittet
- Department of Anesthesiology and Perioperative Medicine, Birmingham School of Medicine, University of Alabama, Birmingham, AL 35294, USA; (J.-F.P.); (B.M.W.)
| | - Brant M. Wagener
- Department of Anesthesiology and Perioperative Medicine, Birmingham School of Medicine, University of Alabama, Birmingham, AL 35294, USA; (J.-F.P.); (B.M.W.)
| | - Jon D. Simmons
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA; (P.R.); (M.P.); (A.-B.A.-M.); (M.F.A.); (T.S.); (J.D.S.); (D.F.A.)
- Department of Pharmacology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA
- Department of Surgery, College of Medicine, University of South Alabama, Mobile, AL 36688, USA
| | - Diego F. Alvarez
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA; (P.R.); (M.P.); (A.-B.A.-M.); (M.F.A.); (T.S.); (J.D.S.); (D.F.A.)
- Department of Physiology and Cell Biology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA
- Department of Physiology and Pharmacology, College of Osteopathic Medicine, Sam Houston State University, Conroe, TX 77304, USA
| | - Jonathon P. Audia
- Department of Microbiology and Immunology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA; (K.S.H.); (A.N.T.); (C.A.S.); (R.A.B.)
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA; (P.R.); (M.P.); (A.-B.A.-M.); (M.F.A.); (T.S.); (J.D.S.); (D.F.A.)
- Correspondence:
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9
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Peñaloza HF, van der Geest R, Ybe JA, Standiford TJ, Lee JS. Interleukin-36 Cytokines in Infectious and Non-Infectious Lung Diseases. Front Immunol 2021; 12:754702. [PMID: 34887860 PMCID: PMC8651476 DOI: 10.3389/fimmu.2021.754702] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 10/14/2021] [Indexed: 12/26/2022] Open
Abstract
The IL-36 family of cytokines were identified in the early 2000’s as a new subfamily of the IL-1 cytokine family, and since then, the role of IL-36 cytokines during various inflammatory processes has been characterized. While most of the research has focused on the role of these cytokines in autoimmune skin diseases such as psoriasis and dermatitis, recent studies have also shown the importance of IL-36 cytokines in the lung inflammatory response during infectious and non-infectious diseases. In this review, we discuss the biology of IL-36 cytokines in terms of how they are produced and activated, as well as their effects on myeloid and lymphoid cells during inflammation. We also discuss the role of these cytokines during lung infectious diseases caused by bacteria and influenza virus, as well as other inflammatory conditions in the lungs such as allergic asthma, lung fibrosis, chronic obstructive pulmonary disease, cystic fibrosis and cancer. Finally, we discuss the current therapeutic advances that target the IL-36 pathway and the possibility to extend these tools to treat lung inflammatory diseases.
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Affiliation(s)
- Hernán F Peñaloza
- Acute Lung Injury Center of Excellence, Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Rick van der Geest
- Acute Lung Injury Center of Excellence, Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Joel A Ybe
- Department of Environmental and Occupational Health, School of Public Health, Indiana University, Bloomington, IN, United States
| | - Theodore J Standiford
- Division of Pulmonary and Critical Care Medicine, University of Michigan, Ann Arbor, MI, United States
| | - Janet S Lee
- Acute Lung Injury Center of Excellence, Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, United States.,Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, United States
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10
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Bagayoko S, Leon-Icaza SA, Pinilla M, Hessel A, Santoni K, Péricat D, Bordignon PJ, Moreau F, Eren E, Boyancé A, Naser E, Lefèvre L, Berrone C, Iakobachvili N, Metais A, Rombouts Y, Lugo-Villarino G, Coste A, Attrée I, Frank DW, Clevers H, Peters PJ, Cougoule C, Planès R, Meunier E. Host phospholipid peroxidation fuels ExoU-dependent cell necrosis and supports Pseudomonas aeruginosa-driven pathology. PLoS Pathog 2021; 17:e1009927. [PMID: 34516571 PMCID: PMC8460005 DOI: 10.1371/journal.ppat.1009927] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 09/23/2021] [Accepted: 08/29/2021] [Indexed: 11/20/2022] Open
Abstract
Regulated cell necrosis supports immune and anti-infectious strategies of the body; however, dysregulation of these processes drives pathological organ damage. Pseudomonas aeruginosa expresses a phospholipase, ExoU that triggers pathological host cell necrosis through a poorly characterized pathway. Here, we investigated the molecular and cellular mechanisms of ExoU-mediated necrosis. We show that cellular peroxidised phospholipids enhance ExoU phospholipase activity, which drives necrosis of immune and non-immune cells. Conversely, both the endogenous lipid peroxidation regulator GPX4 and the pharmacological inhibition of lipid peroxidation delay ExoU-dependent cell necrosis and improve bacterial elimination in vitro and in vivo. Our findings also pertain to the ExoU-related phospholipase from the bacterial pathogen Burkholderia thailandensis, suggesting that exploitation of peroxidised phospholipids might be a conserved virulence mechanism among various microbial phospholipases. Overall, our results identify an original lipid peroxidation-based virulence mechanism as a strong contributor of microbial phospholipase-driven pathology.
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Affiliation(s)
- Salimata Bagayoko
- Institute of Pharmacology and Structural Biology (IPBS), University of Toulouse, CNRS, Toulouse, France
| | - Stephen Adonai Leon-Icaza
- Institute of Pharmacology and Structural Biology (IPBS), University of Toulouse, CNRS, Toulouse, France
| | - Miriam Pinilla
- Institute of Pharmacology and Structural Biology (IPBS), University of Toulouse, CNRS, Toulouse, France
| | - Audrey Hessel
- Institute of Pharmacology and Structural Biology (IPBS), University of Toulouse, CNRS, Toulouse, France
| | - Karin Santoni
- Institute of Pharmacology and Structural Biology (IPBS), University of Toulouse, CNRS, Toulouse, France
| | - David Péricat
- Institute of Pharmacology and Structural Biology (IPBS), University of Toulouse, CNRS, Toulouse, France
| | - Pierre-Jean Bordignon
- Institute of Pharmacology and Structural Biology (IPBS), University of Toulouse, CNRS, Toulouse, France
| | - Flavie Moreau
- Institute of Pharmacology and Structural Biology (IPBS), University of Toulouse, CNRS, Toulouse, France
- Level 3 Biosafety Animal Core facility, Anexplo platform, Institute of Pharmacology and Structural Biology (IPBS), University of Toulouse, CNRS, Toulouse, France
| | - Elif Eren
- Institute of Pharmacology and Structural Biology (IPBS), University of Toulouse, CNRS, Toulouse, France
| | - Aurélien Boyancé
- Institute of Pharmacology and Structural Biology (IPBS), University of Toulouse, CNRS, Toulouse, France
| | - Emmanuelle Naser
- Institute of Pharmacology and Structural Biology (IPBS), University of Toulouse, CNRS, Toulouse, France
- Cytometry & Imaging Core facility, Institute of Pharmacology and Structural Biology (IPBS), University of Toulouse, CNRS, Toulouse, France
| | - Lise Lefèvre
- RESTORE institute, University of Toulouse, CNRS, Toulouse, France
| | - Céline Berrone
- Institute of Pharmacology and Structural Biology (IPBS), University of Toulouse, CNRS, Toulouse, France
- Level 3 Biosafety Animal Core facility, Anexplo platform, Institute of Pharmacology and Structural Biology (IPBS), University of Toulouse, CNRS, Toulouse, France
| | - Nino Iakobachvili
- Division of Nanoscopy, Maastricht Multimodal Molecular Imaging Institute, Maastricht University, Maastricht, The Netherlands
| | - Arnaud Metais
- Institute of Pharmacology and Structural Biology (IPBS), University of Toulouse, CNRS, Toulouse, France
| | - Yoann Rombouts
- Institute of Pharmacology and Structural Biology (IPBS), University of Toulouse, CNRS, Toulouse, France
| | - Geanncarlo Lugo-Villarino
- Institute of Pharmacology and Structural Biology (IPBS), University of Toulouse, CNRS, Toulouse, France
| | - Agnès Coste
- RESTORE institute, University of Toulouse, CNRS, Toulouse, France
| | - Ina Attrée
- Univ. Grenoble Alpes, CNRS, CEA, IBS, Bacterial Pathogenesis and Cellular Responses, Grenoble, France
| | - Dara W. Frank
- Department of Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Hans Clevers
- Oncode Institute, Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences and University Medical Center, Utrecht, Netherlands
| | - Peter J. Peters
- Division of Nanoscopy, Maastricht Multimodal Molecular Imaging Institute, Maastricht University, Maastricht, The Netherlands
| | - Céline Cougoule
- Institute of Pharmacology and Structural Biology (IPBS), University of Toulouse, CNRS, Toulouse, France
| | - Rémi Planès
- Institute of Pharmacology and Structural Biology (IPBS), University of Toulouse, CNRS, Toulouse, France
| | - Etienne Meunier
- Institute of Pharmacology and Structural Biology (IPBS), University of Toulouse, CNRS, Toulouse, France
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11
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Roles of Eicosanoids in Regulating Inflammation and Neutrophil Migration as an Innate Host Response to Bacterial Infections. Infect Immun 2021; 89:e0009521. [PMID: 34031130 DOI: 10.1128/iai.00095-21] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Eicosanoids are lipid-based signaling molecules that play a unique role in innate immune responses. The multiple types of eicosanoids, such as prostaglandins (PGs) and leukotrienes (LTs), allow the innate immune cells to respond rapidly to bacterial invaders. Bacterial pathogens alter cyclooxygenase (COX)-derived prostaglandins (PGs) in macrophages, such as PGE2 15d-PGJ2, and lipoxygenase (LOX)-derived leukotriene LTB4, which has chemotactic functions. The PG synthesis and secretion are regulated by substrate availability of arachidonic acid and by the COX-2 enzyme, and the expression of this protein is regulated at multiple levels, both transcriptionally and posttranscriptionally. Bacterial pathogens use virulence strategies such as type three secretion systems (T3SSs) to deliver virulence factors altering the expression of eicosanoid-specific biosynthetic enzymes, thereby modulating the host response to bacterial lipopolysaccharides (LPS). Recent advances have identified a novel role of eicosanoids in inflammasome activation during intracellular infection with bacterial pathogens. Specifically, PGE2 was found to enhance inflammasome activation, driving the formation of pore-induced intracellular traps (PITs), thus trapping bacteria from escaping the dying cell. Finally, eicosanoids and IL-1β released from macrophages are implicated in the efferocytosis of neighboring neutrophils. Neutrophils play an essential role in phagocytosing and degrading PITs and associated bacteria to restore homeostasis. This review focuses on the novel functions of host-derived eicosanoids in the host-pathogen interactions.
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12
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Brink JTR, Fourie R, Sebolai O, Albertyn J, Pohl CH. The role of lipid droplets in microbial pathogenesis. J Med Microbiol 2021; 70. [PMID: 34184983 DOI: 10.1099/jmm.0.001383] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The nonpolar lipids present in cells are mainly triacylglycerols and steryl esters. When cells are provided with an abundance of nutrients, these storage lipids accumulate. As large quantities of nonpolar lipids cannot be integrated into membranes, they are isolated from the cytosolic environment in lipid droplets. As specialized, inducible cytoplasmic organelles, lipid droplets have functions beyond the regulation of lipid metabolism, in cell signalling and activation, membrane trafficking and control of inflammatory mediator synthesis and secretion. Pathogens, including fungi, viruses, parasites, or intracellular bacteria can induce and may benefit from lipid droplets in infected cells. Here we review biogenesis of lipid droplets as well as the role of lipid droplets in the pathogenesis of selected viruses, bacteria, protists and yeasts.
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Affiliation(s)
- Jacobus T R Brink
- Department of Microbiology and Biochemistry, University of the Free State, Bloemfontein, South Africa
| | - Ruan Fourie
- Department of Microbiology and Biochemistry, University of the Free State, Bloemfontein, South Africa
| | - Olihile Sebolai
- Department of Microbiology and Biochemistry, University of the Free State, Bloemfontein, South Africa
| | - Jacobus Albertyn
- Department of Microbiology and Biochemistry, University of the Free State, Bloemfontein, South Africa
| | - Carolina H Pohl
- Department of Microbiology and Biochemistry, University of the Free State, Bloemfontein, South Africa
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13
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Niu M, Keller NP. Co-opting oxylipin signals in microbial disease. Cell Microbiol 2020; 21:e13025. [PMID: 30866138 DOI: 10.1111/cmi.13025] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 02/01/2019] [Accepted: 02/06/2019] [Indexed: 12/14/2022]
Abstract
Oxylipins, or oxygenated lipids, are universal signalling molecules across all kingdoms of life. These molecules, either produced by microbial pathogens or their mammalian host, regulate inflammation during microbial infection. In this review, we summarise current literature on the biosynthesis pathways of microbial oxylipins and their biological activity towards mammalian cells. Collectively, these studies have illustrated how microbial pathogens can modulate immune rsponse and disease outcome via oxylipin-mediated mechanisms.
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Affiliation(s)
- Mengyao Niu
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin
| | - Nancy P Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin.,Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin
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14
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Riquelme SA, Wong Fok Lung T, Prince A. Pulmonary Pathogens Adapt to Immune Signaling Metabolites in the Airway. Front Immunol 2020; 11:385. [PMID: 32231665 PMCID: PMC7082326 DOI: 10.3389/fimmu.2020.00385] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 02/18/2020] [Indexed: 12/17/2022] Open
Abstract
A limited number of pulmonary pathogens are able to evade normal mucosal defenses to establish acute infection and then adapt to cause chronic pneumonias. Pathogens, such as Pseudomonas aeruginosa or Staphylococcus aureus, are typically associated with infection in patients with underlying pulmonary disease or damage, such as cystic fibrosis (CF) or chronic obstructive pulmonary disease (COPD). To establish infection, bacteria express a well-defined set of so-called virulence factors that facilitate colonization and activate an immune response, gene products that have been identified in murine models. Less well-understood are the adaptive changes that occur over time in vivo, enabling the organisms to evade innate and adaptive immune clearance mechanisms. These colonizers proliferate, generating a population sufficient to provide selection for mutants, such as small colony variants and mucoid variants, that are optimized for long term infection. Such host-adapted strains have evolved in response to selective pressure such as antibiotics and the recruitment of phagocytes at sites of infection and their release of signaling metabolites (e.g., succinate). These metabolites can potentially function as substrates for bacterial growth and but also generate oxidant stress. Whole genome sequencing and quantified expression of selected genes have helped to explain how P. aeruginosa and S. aureus adapt to the presence of these metabolites over the course of in vivo infection. The serial isolation of clonally related strains from patients with cystic fibrosis has provided the opportunity to identify bacterial metabolic pathways that are altered under this immune pressure, such as the anti-oxidant glyoxylate and pentose phosphate pathways, routes contributing to the generation of biofilms. These metabolic pathways and biofilm itself enable the organisms to dissipate oxidant stress, while providing protection from phagocytosis. Stimulation of host immune signaling metabolites by these pathogens drives bacterial adaptation and promotes their persistence in the airways. The inherent metabolic flexibility of P. aeruginosa and S. aureus is a major factor in their success as pulmonary pathogens.
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Affiliation(s)
- Sebastián A Riquelme
- Department of Pediatrics, Columbia University Medical Center, New York, NY, United States
| | - Tania Wong Fok Lung
- Department of Pediatrics, Columbia University Medical Center, New York, NY, United States
| | - Alice Prince
- Department of Pediatrics, Columbia University Medical Center, New York, NY, United States
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15
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Pseudomonas aeruginosa Toxin ExoU as a Therapeutic Target in the Treatment of Bacterial Infections. Microorganisms 2019; 7:microorganisms7120707. [PMID: 31888268 PMCID: PMC6955817 DOI: 10.3390/microorganisms7120707] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 12/10/2019] [Accepted: 12/14/2019] [Indexed: 12/20/2022] Open
Abstract
The opportunistic pathogen Pseudomonas aeruginosa employs the type III secretion system (T3SS) and four effector proteins, ExoS, ExoT, ExoU, and ExoY, to disrupt cellular physiology and subvert the host’s innate immune response. Of the effector proteins delivered by the T3SS, ExoU is the most toxic. In P. aeruginosa infections, where the ExoU gene is expressed, disease severity is increased with poorer prognoses. This is considered to be due to the rapid and irreversible damage exerted by the phospholipase activity of ExoU, which cannot be halted before conventional antibiotics can successfully eliminate the pathogen. This review will discuss what is currently known about ExoU and explore its potential as a therapeutic target, highlighting some of the small molecule ExoU inhibitors that have been discovered from screening approaches.
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16
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Ahator SD, Zhang L. Small Is Mighty—Chemical Communication Systems in Pseudomonas aeruginosa. Annu Rev Microbiol 2019; 73:559-578. [DOI: 10.1146/annurev-micro-020518-120044] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen that causes a variety of acute and chronic infections. Usually a commensal on the host body, P. aeruginosa is capable of transforming into a virulent pathogen upon sensing favorable changes in the host immune system or stress cues. P. aeruginosa infections are hard to eradicate, because this pathogen has developed strong resistance to most conventional antibiotics; in addition, in chronic infections it commonly forms a biofilm matrix, which provides bacterial cells a protected environment to withstand various stresses including antibiotics. Given its importance as a human pathogen and its notorious antimicrobial tolerance, P. aeruginosa has been the subject of intensive investigations internationally. Research progress over the last two decades has unveiled a range of chemical communication systems in this pathogen. These diversified chemical communication systems endow P. aeruginosa a superb ability and remarkable flexibility to coordinate and modulate accordingly the transcriptional expression of various sets of genes associated with virulence and other physiologic activities in response to environmental changes. A fair understanding of the chemical signaling mechanisms with which P. aeruginosa governs virulence gene expression may hold the key to developing alternative therapeutic interventions that control and prevent bacterial infections.
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Affiliation(s)
- Stephen Dela Ahator
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Center, South China Agricultural University, Guangzhou 510642, China
| | - LianHui Zhang
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Center, South China Agricultural University, Guangzhou 510642, China
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17
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Pereira-Dutra FS, Teixeira L, de Souza Costa MF, Bozza PT. Fat, fight, and beyond: The multiple roles of lipid droplets in infections and inflammation. J Leukoc Biol 2019; 106:563-580. [PMID: 31121077 DOI: 10.1002/jlb.4mr0119-035r] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2019] [Revised: 04/16/2019] [Accepted: 04/26/2019] [Indexed: 12/12/2022] Open
Abstract
Increased accumulation of cytoplasmic lipid droplets (LDs) in host nonadipose cells is commonly observed in response to numerous infectious diseases, including bacterial, parasite, and fungal infections. LDs are lipid-enriched, dynamic organelles composed of a core of neutral lipids surrounded by a monolayer of phospholipids associated with a diverse array of proteins that are cell and stimulus regulated. Far beyond being simply a deposit of neutral lipids, LDs have come to be seen as an essential platform for various cellular processes, including metabolic regulation, cell signaling, and the immune response. LD participation in the immune response occurs as sites for compartmentalization of several immunometabolic signaling pathways, production of inflammatory lipid mediators, and regulation of antigen presentation. Infection-driven LD biogenesis is a complexly regulated process that involves innate immune receptors, transcriptional and posttranscriptional regulation, increased lipid uptake, and new lipid synthesis. Accumulating evidence demonstrates that intracellular pathogens are able to exploit LDs as an energy source, a replication site, and/or a mechanism of immune response evasion. Nevertheless, LDs can also act in favor of the host as part of the immune and inflammatory response to pathogens. Here, we review recent findings that explored the new roles of LDs in the context of host-pathogen interactions.
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Affiliation(s)
- Filipe S Pereira-Dutra
- Laboratório de Imunofarmacologia, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | - Livia Teixeira
- Laboratório de Imunofarmacologia, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | | | - Patrícia T Bozza
- Laboratório de Imunofarmacologia, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
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18
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Lipid Droplets: A Significant but Understudied Contributor of Host⁻Bacterial Interactions. Cells 2019; 8:cells8040354. [PMID: 30991653 PMCID: PMC6523240 DOI: 10.3390/cells8040354] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Revised: 04/05/2019] [Accepted: 04/12/2019] [Indexed: 12/13/2022] Open
Abstract
Lipid droplets (LDs) are cytosolic lipid storage organelles that are important for cellular lipid metabolism, energy homeostasis, cell signaling, and inflammation. Several bacterial, viral and protozoal pathogens exploit host LDs to promote infection, thus emphasizing the importance of LDs at the host–pathogen interface. In this review, we discuss the thus far reported relation between host LDs and bacterial pathogens including obligate and facultative intracellular bacteria, and extracellular bacteria. Although there is less evidence for a LD–extracellular bacterial interaction compared to interactions with intracellular bacteria, in this review, we attempt to compare the bacterial mechanisms that target LDs, the host signaling pathways involved and the utilization of LDs by these bacteria. Many intracellular bacteria employ unique mechanisms to target host LDs and potentially obtain nutrients and lipids for vacuolar biogenesis and/or immune evasion. However, extracellular bacteria utilize LDs to either promote host tissue damage or induce host death. We also identify several areas that require further investigation. Along with identifying LD interactions with bacteria besides the ones reported, the precise mechanisms of LD targeting and how LDs benefit pathogens should be explored for the bacteria discussed in the review. Elucidating LD–bacterial interactions promises critical insight into a novel host–pathogen interaction.
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19
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Belmadi N, Wu Y, Touqui L. Immuno-modulatory functions of the type-3 secretion system and impacts on the pulmonary host defense: A role for ExoS of Pseudomonas aeruginosa in cystic fibrosis. Toxicon 2018; 143:68-73. [PMID: 29339019 DOI: 10.1016/j.toxicon.2018.01.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2017] [Revised: 01/08/2018] [Accepted: 01/09/2018] [Indexed: 12/27/2022]
Abstract
Number of previous reviews had described the structures and the various functions of the exotoxins produced by the type-3 secretion system of Pseudomonas aeruginosa and their roles in the interactions of this bacterium with host cells. In this review, we summarize some relevant data of literature on ExoS, an exotoxin from the type-3 secretion system of P. aeruginosa, with a particular focus on the role of this toxin in the airways innate response of the host to infection by this bacterium, and its implication in the elimination of Staphylococcus aureus from the airways of patients with cystic fibrosis.
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Affiliation(s)
- Nawal Belmadi
- Mucoviscidose et Bronchopathies Chroniques, Unité Mixte Institut Pasteur/Paris V, Faculté de Médecine Cochin, Paris, France
| | - Yongzheng Wu
- Unité de Biologie cellulaire de l'infection microbienne, CNRS, UMR 3691, Institut Pasteur, Paris, France
| | - Lhousseine Touqui
- Mucoviscidose et Bronchopathies Chroniques, Unité Mixte Institut Pasteur/Paris V, Faculté de Médecine Cochin, Paris, France.
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20
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Aoyagi T, Newstead MW, Zeng X, Nanjo Y, Peters-Golden M, Kaku M, Standiford TJ. Interleukin-36γ and IL-36 receptor signaling mediate impaired host immunity and lung injury in cytotoxic Pseudomonas aeruginosa pulmonary infection: Role of prostaglandin E2. PLoS Pathog 2017; 13:e1006737. [PMID: 29166668 PMCID: PMC5718565 DOI: 10.1371/journal.ppat.1006737] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2017] [Revised: 12/06/2017] [Accepted: 11/07/2017] [Indexed: 12/21/2022] Open
Abstract
Pseudomonas aeruginosa is a Gram-negative pathogen that can lead to severe infection associated with lung injury and high mortality. The interleukin (IL)-36 cytokines (IL-36α, IL-36β and IL-36γ) are newly described IL-1 like family cytokines that promote inflammatory response via binding to the IL-36 receptor (IL-36R). Here we investigated the functional role of IL-36 cytokines in the modulating of innate immune response against P. aeruginosa pulmonary infection. The intratracheal administration of flagellated cytotoxic P. aeruginosa (ATCC 19660) upregulated IL-36α and IL-36γ, but not IL-36β, in the lungs. IL-36α and IL-36γ were expressed in pulmonary macrophages (PMs) and alveolar epithelial cells in response to P. aeruginosa in vitro. Mortality after bacterial challenge in IL-36 receptor deficient (IL-36R-/-) mice and IL-36γ deficient (IL-36γ-/-) mice, but not IL-36α deficient mice, was significantly lower than that of wild type mice. Decreased mortality in IL-36R-/- mice and IL-36γ-/- mice was associated with reduction in bacterial burden in the alveolar space, bacterial dissemination, production of inflammatory cytokines and lung injury, without changes in lung leukocyte influx. Interestingly, IL-36γ enhanced the production of prostaglandin E2 (PGE2) during P. aeruginosa infection in vivo and in vitro. Treatment of PMs with recombinant IL-36γ resulted in impaired bacterial killing via PGE2 and its receptor; EP2. P. aeruginosa infected EP2 deficient mice or WT mice treated with a COX-2-specific inhibitor showed decreased bacterial burden and dissemination, but no change in lung injury. Finally, we observed an increase in IL-36γ, but not IL-36α, in the airspace and plasma of patients with P. aeruginosa-induced acute respiratory distress syndrome. Thus, IL-36γ and its receptor signal not only impaired bacterial clearance in a possible PGE2 dependent fashion but also mediated lung injury during P. aeruginosa infection.
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Affiliation(s)
- Tetsuji Aoyagi
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Infection Control and Laboratory Diagnostics, Internal Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan
- * E-mail:
| | - Michael W. Newstead
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Xianying Zeng
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Yuta Nanjo
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Microbiology and Infectious Diseases, Toho University School of Medicine, Tokyo, Japan
| | - Marc Peters-Golden
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Mitsuo Kaku
- Department of Infection Control and Laboratory Diagnostics, Internal Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Theodore J. Standiford
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, United States of America
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21
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Hiller M, Lang C, Michel W, Flieger A. Secreted phospholipases of the lung pathogen Legionella pneumophila. Int J Med Microbiol 2017; 308:168-175. [PMID: 29108710 DOI: 10.1016/j.ijmm.2017.10.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 10/06/2017] [Accepted: 10/22/2017] [Indexed: 11/28/2022] Open
Abstract
Legionella pneumophila is an intracellular pathogen and the main causative agent of Legionnaires' disease, a potentially fatal pneumonia. The bacteria infect both mammalian cells and environmental hosts, such as amoeba. Inside host cells, the bacteria withstand the multifaceted defenses of the phagocyte and replicate within a unique membrane-bound compartment, the Legionella-containing vacuole (LCV). For establishment and maintenance of the infection, L. pneumophila secretes many proteins including effector proteins by means of different secretion systems and outer membrane vesicles. Among these are a large variety of lipolytic enzymes which possess phospholipase/lysophospholipase and/or glycerophospholipid:cholesterol acyltransferase activities. Secreted lipolytic activities may contribute to bacterial virulence, for example via modification of eukaryotic membranes, such as the LCV. In this review, we describe the secretion systems of L. pneumophila, introduce the classification of phospholipases, and summarize the state of the art on secreted L. pneumophila phospholipases. We especially highlight those enzymes secreted via the type II secretion system Lsp, via the type IVB secretion system Dot/Icm, via outer membrane vesicles, and such where the mode of secretion has not yet been defined. We also give an overview on the complexity of their activities, activation mechanisms, localization, growth-phase dependent abundance, and their role in infection.
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Affiliation(s)
- Miriam Hiller
- Division of Enteropathogenic Bacteria and Legionella, Robert Koch-Institute, Burgstraße 37, 38855 Wernigerode, Germany
| | - Christina Lang
- Division of Enteropathogenic Bacteria and Legionella, Robert Koch-Institute, Burgstraße 37, 38855 Wernigerode, Germany
| | - Wiebke Michel
- Division of Enteropathogenic Bacteria and Legionella, Robert Koch-Institute, Burgstraße 37, 38855 Wernigerode, Germany
| | - Antje Flieger
- Division of Enteropathogenic Bacteria and Legionella, Robert Koch-Institute, Burgstraße 37, 38855 Wernigerode, Germany.
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22
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Pazos MA, Lanter BB, Yonker LM, Eaton AD, Pirzai W, Gronert K, Bonventre JV, Hurley BP. Pseudomonas aeruginosa ExoU augments neutrophil transepithelial migration. PLoS Pathog 2017; 13:e1006548. [PMID: 28771621 PMCID: PMC5557605 DOI: 10.1371/journal.ppat.1006548] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 08/15/2017] [Accepted: 07/22/2017] [Indexed: 12/21/2022] Open
Abstract
Excessive neutrophil infiltration of the lungs is a common contributor to immune-related pathology in many pulmonary disease states. In response to pathogenic infection, airway epithelial cells produce hepoxilin A3 (HXA3), initiating neutrophil transepithelial migration. Migrated neutrophils amplify this recruitment by producing a secondary gradient of leukotriene B4 (LTB4). We sought to determine whether this two-step eicosanoid chemoattractant mechanism could be exploited by the pathogen Pseudomonas aeruginosa. ExoU, a P. aeruginosa cytotoxin, exhibits phospholipase A2 (PLA2) activity in eukaryotic hosts, an enzyme critical for generation of certain eicosanoids. Using in vitro and in vivo models of neutrophil transepithelial migration, we evaluated the impact of ExoU expression on eicosanoid generation and function. We conclude that ExoU, by virtue of its PLA2 activity, augments and compensates for endogenous host neutrophil cPLA2α function, leading to enhanced transepithelial migration. This suggests that ExoU expression in P. aeruginosa can circumvent immune regulation at key signaling checkpoints in the neutrophil, resulting in exacerbated neutrophil recruitment. Pseudomonas aeruginosa is an opportunistic pathogen that causes acute pneumonia in immune compromised patients, and infects 70–80% of patients suffering from cystic fibrosis. Infections can result in excessive airway inflammation, which lead to immune-mediated lung damage, in particular through the action of recruited white blood cells known as neutrophils. Certain strains of P. aeruginosa produce the exotoxin ExoU, which has been associated with increased virulence. ExoU causes host cell lysis by hydrolyzing host membrane lipids through its phospholipase activity. However, host phospholipases play a key role in immune signaling by mediating the production of lipids known as eicosanoids. We investigated whether separate from its cytolytic activity, ExoU could modulate host immune responses through its phospholipase activity by hijacking eicosanoid production. Using in vitro and in vivo models of neutrophil recruitment, we find that ExoU producing strains of P. aeruginosa elicit higher levels of the eicosanoid chemoattractant leukotriene B4 from migrated neutrophils. This results in increased neutrophil transepithelial migration. This work reveals a new mechanism for how bacterial pathogens alter our immune function, and highlights a new potential therapeutic strategy for moderating Pseudomonas pathogenesis in patients with cystic fibrosis and acute pneumonia.
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Affiliation(s)
- Michael A. Pazos
- Mucosal Immunology & Biology Research Center, Massachusetts General Hospital for Children, Boston, Massachusetts, United States of America
- Pediatrics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Bernard B. Lanter
- Mucosal Immunology & Biology Research Center, Massachusetts General Hospital for Children, Boston, Massachusetts, United States of America
- Pediatrics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Lael M. Yonker
- Mucosal Immunology & Biology Research Center, Massachusetts General Hospital for Children, Boston, Massachusetts, United States of America
- Pediatrics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Alex D. Eaton
- Mucosal Immunology & Biology Research Center, Massachusetts General Hospital for Children, Boston, Massachusetts, United States of America
| | - Waheed Pirzai
- Mucosal Immunology & Biology Research Center, Massachusetts General Hospital for Children, Boston, Massachusetts, United States of America
| | - Karsten Gronert
- Vision Science Program, School of Optometry, University of California at Berkeley, Berkeley, California, United States of America
| | - Joseph V. Bonventre
- Renal Division and Biomedical Engineering Division, Brigham and Women's Hospital, Department of Medicine, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Bryan P. Hurley
- Mucosal Immunology & Biology Research Center, Massachusetts General Hospital for Children, Boston, Massachusetts, United States of America
- Pediatrics, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
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23
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Benie CKD, Dadié A, Guessennd N, N'gbesso-Kouadio NA, Kouame ND, N'golo DC, Aka S, Dako E, Dje KM, Dosso M. Characterization of Virulence Potential of Pseudomonas Aeruginosa Isolated from Bovine Meat, Fresh Fish, and Smoked Fish. Eur J Microbiol Immunol (Bp) 2017; 7:55-64. [PMID: 28386471 PMCID: PMC5372481 DOI: 10.1556/1886.2016.00039] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 01/12/2017] [Indexed: 11/19/2022] Open
Abstract
Pseudomonas aeruginosa owns a variability of virulence factors. These factors can increase bacterial pathogenicity and infection severity. Despite the importance of knowledge about them, these factors are not more characterized at level of strains derived from local food products. This study aimed to characterize the virulence potential of P. aeruginosa isolated from various animal products. Several structural and virulence genes of P. aeruginosa including lasB, exoS, algD, plcH, pilB, exoU, and nan1 were detected by polymerase chain reaction (PCR) on 204 strains of P. aeruginosa. They were isolated from bovine meat (122), fresh fish (49), and smoked fish (33). The 16S rRNA gene was detected on 91.1% of the presumptive strains as Pseudomonas. The rpoB gene showed that 99.5% of the strains were P. aeruginosa. The lasB gene (89.2%) was the most frequently detected (p < 0.05). In decreasing importance order, exoS (86.8%), algD (72.1%), plcH (72.1%), pilB (40.2%), and exoU (2.5%) were detected. The lasB gene was detected in all strains of P. aeruginosa serogroups O11 and O16. The prevalence of algD, exoS, and exoU genes in these strains varied from 51.2% to 87.4%. The simultaneous determination of serogroups and virulence factors is of interest for the efficacy of surveillance of infections associated with P. aeruginosa.
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Affiliation(s)
- Comoé Koffi Donatien Benie
- Laboratory of Biotechnology and Food Microbiology (LMBM), University of Nangui-Abrogoua, 02 BP 801, Abidjan 02, Côte d'Ivoire; Department of Bacteriology and Virology, Institut Pasteur of Côte d'Ivoire (IPCI), 01 BP 490, Abidjan 01, Côte d'Ivoire
| | - Adjéhi Dadié
- Laboratory of Biotechnology and Food Microbiology (LMBM), University of Nangui-Abrogoua, 02 BP 801, Abidjan 02, Côte d'Ivoire; Department of Bacteriology and Virology, Institut Pasteur of Côte d'Ivoire (IPCI), 01 BP 490, Abidjan 01, Côte d'Ivoire
| | - Nathalie Guessennd
- Department of Bacteriology and Virology, Institut Pasteur of Côte d'Ivoire (IPCI), 01 BP 490, Abidjan 01, Côte d'Ivoire; Faculty of Medical Sciences, University of Félix Houphouët Boigny, 01 BP V4, Abidjan 01, Côte d'Ivoire
| | - Nadège Ahou N'gbesso-Kouadio
- Laboratory of Biotechnology and Food Microbiology (LMBM), University of Nangui-Abrogoua , 02 BP 801, Abidjan 02, Côte d'Ivoire
| | - N'zebo Désiré Kouame
- Laboratory of Biotechnology and Food Microbiology (LMBM), University of Nangui-Abrogoua , 02 BP 801, Abidjan 02, Côte d'Ivoire
| | - David Coulibaly N'golo
- Department of Bacteriology and Virology, Institut Pasteur of Côte d'Ivoire (IPCI) , 01 BP 490, Abidjan 01, Côte d'Ivoire
| | - Solange Aka
- Laboratory of Biotechnology and Food Microbiology (LMBM), University of Nangui-Abrogoua , 02 BP 801, Abidjan 02, Côte d'Ivoire
| | - Etienne Dako
- School of Food Science, Nutrition and Family Studies Faculty of Health Sciences and Community Services, University of Moncton, Moncton , NB E1A 3E9, Canada
| | - Koffi Marcellin Dje
- Laboratory of Biotechnology and Food Microbiology (LMBM), University of Nangui-Abrogoua , 02 BP 801, Abidjan 02, Côte d'Ivoire
| | - Mireille Dosso
- Department of Bacteriology and Virology, Institut Pasteur of Côte d'Ivoire (IPCI), 01 BP 490, Abidjan 01, Côte d'Ivoire; Faculty of Medical Sciences, University of Félix Houphouët Boigny, 01 BP V4, Abidjan 01, Côte d'Ivoire
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24
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Fourie R, Ells R, Kemp G, Sebolai OM, Albertyn J, Pohl CH. Pseudomonas aeruginosa produces aspirin insensitive eicosanoids and contributes to the eicosanoid profile of polymicrobial biofilms with Candida albicans. Prostaglandins Leukot Essent Fatty Acids 2017; 117:36-46. [PMID: 28237086 DOI: 10.1016/j.plefa.2017.01.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 12/16/2016] [Accepted: 01/24/2017] [Indexed: 11/22/2022]
Abstract
The interaction of clinically relevant microorganisms is the focus of various studies, e.g. the interaction between the pathogenic yeast, Candida albicans, and the bacterium, Pseudomonas aeruginosa. During infection both release arachidonic acid, which they can transform into eicosanoids. This study evaluated the production of prostaglandin E2, prostaglandin F2α and 15-hydroxyeicosatetraenoic acid by biofilms of P. aeruginosa and C. albicans. The influence of co-incubation, acetylsalicylic acid and nordihydroguaiaretic acid on biofilm formation and eicosanoid production was evaluated. Acetylsalicylic acid decreased colony forming units of P. aeruginosa, but increased metabolic activity and eicosanoid production of the cells. In contrast to prostaglandin E2, prostaglandin F2a production by C. albicans was insensitive to acetylsalicylic acid, indicating that different enzymes are responsible for their production in this yeast. Nordihydroguaiaretic acid inhibited biofilm formation by P. aeruginosa, however co-incubation provided protection against this inhibitor. Production of these eicosanoids could affect pathogen-clearance and infection dynamics and this previously uncharacterized facet of interaction could facilitate novel therapeutic intervention against polymicrobial infection.
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Affiliation(s)
- Ruan Fourie
- Department of Microbial, Biochemical and Food Biotechnology, University of the Free State, Bloemfontein, South Africa
| | - Ruan Ells
- Department of Microbial, Biochemical and Food Biotechnology, University of the Free State, Bloemfontein, South Africa; National Control Laboratory for Biological Products, University of the Free State, Bloemfontein, South Africa
| | - Gabré Kemp
- Department of Microbial, Biochemical and Food Biotechnology, University of the Free State, Bloemfontein, South Africa
| | - Olihile M Sebolai
- Department of Microbial, Biochemical and Food Biotechnology, University of the Free State, Bloemfontein, South Africa
| | - Jacobus Albertyn
- Department of Microbial, Biochemical and Food Biotechnology, University of the Free State, Bloemfontein, South Africa
| | - Carolina H Pohl
- Department of Microbial, Biochemical and Food Biotechnology, University of the Free State, Bloemfontein, South Africa.
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25
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Lubkin A, Torres VJ. Bacteria and endothelial cells: a toxic relationship. Curr Opin Microbiol 2016; 35:58-63. [PMID: 28013162 DOI: 10.1016/j.mib.2016.11.008] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 11/26/2016] [Accepted: 11/30/2016] [Indexed: 12/24/2022]
Abstract
Pathogenic bacteria use the bloodstream as a highway for getting around the body, and thus have to find ways to enter and exit through the endothelium. Many bacteria approach this problem by producing toxins that can breach the endothelial barrier through diverse creative mechanisms, including directly killing endothelial cells (ECs), weakening the cytoskeleton within ECs, and breaking the junctions between ECs. Toxins can also modulate the immune response by influencing endothelial biology, and can modulate endothelial function by influencing the response of leukocytes. Understanding these interactions, in both the in vitro and in vivo contexts, is of critical importance for designing new therapies for sepsis and other severe bacterial diseases.
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Affiliation(s)
- Ashira Lubkin
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, United States
| | - Victor J Torres
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, United States.
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26
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Pseudomonas aeruginosa sabotages the generation of host proresolving lipid mediators. Proc Natl Acad Sci U S A 2016; 114:136-141. [PMID: 27980032 PMCID: PMC5224368 DOI: 10.1073/pnas.1610242114] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Recurrent Pseudomonas aeruginosa infections coupled with robust, damaging neutrophilic inflammation characterize the chronic lung disease cystic fibrosis (CF). The proresolving lipid mediator, 15-epi lipoxin A4 (15-epi LXA4), plays a critical role in limiting neutrophil activation and tissue inflammation, thus promoting the return to tissue homeostasis. Here, we show that a secreted P. aeruginosa epoxide hydrolase, cystic fibrosis transmembrane conductance regulator inhibitory factor (Cif), can disrupt 15-epi LXA4 transcellular biosynthesis and function. In the airway, 15-epi LXA4 production is stimulated by the epithelial-derived eicosanoid 14,15-epoxyeicosatrienoic acid (14,15-EET). Cif sabotages the production of 15-epi LXA4 by rapidly hydrolyzing 14,15-EET into its cognate diol, eliminating a proresolving signal that potently suppresses IL-8-driven neutrophil transepithelial migration in vitro. Retrospective analyses of samples from patients with CF supported the translational relevance of these preclinical findings. Elevated levels of Cif in bronchoalveolar lavage fluid were correlated with lower levels of 15-epi LXA4, increased IL-8 concentrations, and impaired lung function. Together, these findings provide structural, biochemical, and immunological evidence that the bacterial epoxide hydrolase Cif disrupts resolution pathways during bacterial lung infections. The data also suggest that Cif contributes to sustained pulmonary inflammation and associated loss of lung function in patients with CF.
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27
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Park MH, Kim SY, Roh EY, Lee HS. Difference of Type 3 secretion system (T3SS) effector gene genotypes (exoU and exoS) and its implication to antibiotics resistances in isolates of Pseudomonas aeruginosa from chronic otitis media. Auris Nasus Larynx 2016; 44:258-265. [PMID: 27461174 DOI: 10.1016/j.anl.2016.07.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Revised: 06/30/2016] [Accepted: 07/05/2016] [Indexed: 01/15/2023]
Abstract
OBJECTIVE Type 3 secretion system (T3SS) is the most important virulence factor in Pseudomonas aeruginosa infection. Of the various T3SS effector genes, exoS and exoU showed mutually exclusive distributions, and these two genes showed varied virulence. In many pseudomonal infections, the distribution of these genes showed different pattern and it influenced severity of infection. This study was aimed to evaluate differences of virulence factors and antibiotics resistance between chronic otitis media and other body infection caused by P. aeruginosa. METHODS To estimate the prevalence of effector genes of T3SS, especially the distributions of exoS and exoU genes and their association with antibiotic resistance in COM, we compared the prevalence of T3SS genes in isolates from COM with those from lower respiratory infection and bacteremia. Other virulence genes, including groEL, pilA, ndvB, lasB, rhlI, and apr, were also studied to evaluate prevalence. These isolates were tested for antibiotic susceptibility, and we examined the association between antibiotic susceptibility and the prevalence of T3SS effector genes. RESULTS The COM group showed a significantly higher exoU-positive rate than the control group (70.6% vs. 6.7%; P<0.01). Furthermore, COM patients with exoU showed significant antibiotic resistance to ciprofloxacin and tobramycin (P=0.035), whereas there was no significant difference in the control group. CONCLUSIONS The high incidence of exoU-positive P. aeruginosa and ciprofloxacin resistance can explain the chronicity and intractability of infection in COM. Elucidation of this pathogenicity will facilitate the development of new treatment options for COM patients.
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Affiliation(s)
- Min-Hyun Park
- Department of Otorhinolaryngology-Head and Neck Surgery, Boramae Medical Center, Seoul Metropolitan Government-Seoul National University, Seoul, Republic of Korea
| | - So Young Kim
- Department of Otorhinolaryngology-Head and Neck Surgery, CHA Bundang Medical Center, CHA University, Seongnam, Republic of Korea.
| | - Eun Yun Roh
- Department of Clinical Laboratory Medicine, Boramae Medical Center, Seoul Metropolitan Government-Seoul National University, Seoul, Republic of Korea
| | - Ho Sun Lee
- Department of Otorhinolaryngology-Head and Neck Surgery, Boramae Medical Center, Seoul Metropolitan Government-Seoul National University, Seoul, Republic of Korea
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28
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Anantharajah A, Mingeot-Leclercq MP, Van Bambeke F. Targeting the Type Three Secretion System in Pseudomonas aeruginosa. Trends Pharmacol Sci 2016; 37:734-749. [PMID: 27344210 DOI: 10.1016/j.tips.2016.05.011] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Revised: 05/15/2016] [Accepted: 05/17/2016] [Indexed: 12/11/2022]
Abstract
The injectisome type three secretion system (T3SS) is a major virulence factor in Pseudomonas aeruginosa. This bacterium is responsible for severe infections in immunosuppressed or cystic fibrosis patients and has become resistant to many antibiotics. Inhibitors of T3SS may therefore constitute an innovative therapeutic target. After a brief description of the T3SS and its regulation, this review presents strategies to inhibit T3SS-mediated toxicity and describes the main families of existing inhibitors. Over the past few years, 12 classes of small-molecule inhibitors and two types of antibody have been discovered and evaluated in vitro for their capacity to inhibit T3SS expression or function, and to protect host cells from T3SS-mediated cytotoxicity. While only one small molecule has been tested in vivo, a bifunctional antibody targeting both the translocation apparatus of the T3SS and a surface polysaccharide is currently in Phase II clinical trials.
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Affiliation(s)
- Ahalieyah Anantharajah
- Pharmacologie Cellulaire et Moléculaire, Louvain Drug Research Institute, Université Catholique de Louvain, Brussels, Belgium
| | - Marie-Paule Mingeot-Leclercq
- Pharmacologie Cellulaire et Moléculaire, Louvain Drug Research Institute, Université Catholique de Louvain, Brussels, Belgium
| | - Françoise Van Bambeke
- Pharmacologie Cellulaire et Moléculaire, Louvain Drug Research Institute, Université Catholique de Louvain, Brussels, Belgium.
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29
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Abstract
Bacterial sphingomyelinases and phospholipases are a heterogeneous group of esterases which are usually surface associated or secreted by a wide variety of Gram-positive and Gram-negative bacteria. These enzymes hydrolyze sphingomyelin and glycerophospholipids, respectively, generating products identical to the ones produced by eukaryotic enzymes which play crucial roles in distinct physiological processes, including membrane dynamics, cellular signaling, migration, growth, and death. Several bacterial sphingomyelinases and phospholipases are essential for virulence of extracellular, facultative, or obligate intracellular pathogens, as these enzymes contribute to phagosomal escape or phagosomal maturation avoidance, favoring tissue colonization, infection establishment and progression, or immune response evasion. This work presents a classification proposal for bacterial sphingomyelinases and phospholipases that considers not only their enzymatic activities but also their structural aspects. An overview of the main physiopathological activities is provided for each enzyme type, as are examples in which inactivation of a sphingomyelinase- or a phospholipase-encoding gene impairs the virulence of a pathogen. The identification of sphingomyelinases and phospholipases important for bacterial pathogenesis and the development of inhibitors for these enzymes could generate candidate vaccines and therapeutic agents, which will diminish the impacts of the associated human and animal diseases.
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30
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Fourie R, Ells R, Swart CW, Sebolai OM, Albertyn J, Pohl CH. Candida albicans and Pseudomonas aeruginosa Interaction, with Focus on the Role of Eicosanoids. Front Physiol 2016; 7:64. [PMID: 26955357 PMCID: PMC4767902 DOI: 10.3389/fphys.2016.00064] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 02/11/2016] [Indexed: 12/20/2022] Open
Abstract
Candida albicans is commonly found in mixed infections with Pseudomonas aeruginosa, especially in the lungs of cystic fibrosis (CF) patients. Both of these opportunistic pathogens are able to form resistant biofilms and frequently infect immunocompromised individuals. The interaction between these two pathogens, which includes physical interaction as well as secreted factors, is mainly antagonistic. In addition, research suggests considerable interaction with their host, especially with immunomodulatory lipid mediators, termed eicosanoids. Candida albicans and Pseudomonas aeruginosa are both able to utilize arachidonic acid (AA), liberated from the host cells during infection, to form eicosanoids. The production of these eicosanoids, such as Prostaglandin E2, by the host and the pathogens may affect the dynamics of polymicrobial infection and the outcome of infections. It is of considerable importance to elucidate the role of host-produced, as well as pathogen-produced eicosanoids in polymicrobial infection. This review will focus on in vitro as well as in vivo interaction between C. albicans and P. aeruginosa, paying special attention to the role of eicosanoids in the cross-talk between host and the pathogens.
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Affiliation(s)
- Ruan Fourie
- Pathogenic Yeast Research Group, Department of Microbial, Biochemical and Food Biotechnology, University of the Free State Bloemfontein, South Africa
| | - Ruan Ells
- Pathogenic Yeast Research Group, Department of Microbial, Biochemical and Food Biotechnology, University of the Free StateBloemfontein, South Africa; National Control Laboratory, University of the Free StateBloemfontein, South Africa
| | - Chantel W Swart
- Pathogenic Yeast Research Group, Department of Microbial, Biochemical and Food Biotechnology, University of the Free State Bloemfontein, South Africa
| | - Olihile M Sebolai
- Pathogenic Yeast Research Group, Department of Microbial, Biochemical and Food Biotechnology, University of the Free State Bloemfontein, South Africa
| | - Jacobus Albertyn
- Pathogenic Yeast Research Group, Department of Microbial, Biochemical and Food Biotechnology, University of the Free State Bloemfontein, South Africa
| | - Carolina H Pohl
- Pathogenic Yeast Research Group, Department of Microbial, Biochemical and Food Biotechnology, University of the Free State Bloemfontein, South Africa
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31
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Plotkowski MC, Estato V, Santos SA, da Silva MCA, Miranda AS, de Miranda PE, Pinho V, Tibiriça E, Morandi V, Teixeira MM, Vianna A, Saliba AM. Contribution of the platelet activating factor signaling pathway to cerebral microcirculatory dysfunction during experimental sepsis by ExoU producing Pseudomonas aeruginosa. Pathog Dis 2015; 73:ftv046. [PMID: 26187894 DOI: 10.1093/femspd/ftv046] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/10/2015] [Indexed: 12/18/2022] Open
Abstract
Intravital microscopy was used to assess the involvement of ExoU, a Pseudomonas aeruginosa cytotoxin with phospholipase A2 activity, in dysfunction of cerebral microcirculation during experimental pneumosepsis. Cortical vessels from mice intratracheally infected with low density of the ExoU-producing PA103 P. aeruginosa strain exhibited increased leukocyte rolling and adhesion to venule endothelium, decreased capillar density and impaired arteriolar response to vasoactive acetylcholine. These phenomena were mediated by the platelet activating factor receptor (PAFR) pathway because they were reversed in mice treated with a PAFR antagonist prior to infection. Brains from PA103-infected animals exhibited a perivascular inflammatory infiltration that was not detected in animals infected with an exoU deficient mutant or in mice treated with the PAFR antagonist and infected with the wild type bacteria. No effect on brain capillary density was detected in mice infected with the PAO1 P. aeruginosa strain, which do not produce ExoU. Finally, after PA103 infection, mice with a targeted deletion of the PAFR gene exhibited higher brain capillary density and lower leukocyte adhesion to venule endothelium, as well as lower increase of systemic inflammatory cytokines, when compared to wild-type mice. Altogether, our results establish a role for PAFR in mediating ExoU-induced cerebral microvascular failure in a murine model of sepsis.
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Affiliation(s)
- Maria Cristina Plotkowski
- Department of Microbiology, Immunology and Parasitology, State University of Rio de Janeiro, 20551-30 Rio de Janeiro, Brazil
| | - Vanessa Estato
- Laboratory of Cardiovascular Investigation, Oswaldo Cruz Institute, Rio de Janeiro, 21045-900, Brazil
| | - Sabrina Alves Santos
- Department of Microbiology, Immunology and Parasitology, State University of Rio de Janeiro, 20551-30 Rio de Janeiro, Brazil
| | | | - Aline Silva Miranda
- Department of Biochemistry and Immunology, Federal University of Minas Gerais, Belo Horizonte, 31270-901, Brazil
| | - Pedro Elias de Miranda
- Department of Biochemistry and Immunology, Federal University of Minas Gerais, Belo Horizonte, 31270-901, Brazil
| | - Vanessa Pinho
- Department of Morphology, Federal University of Minas Gerais, Belo Horizonte, 31270-901, Brazil
| | - Eduardo Tibiriça
- Laboratory of Cardiovascular Investigation, Oswaldo Cruz Institute, Rio de Janeiro, 21045-900, Brazil
| | - Verônica Morandi
- Department of Cell Biology, State University of Rio de Janeiro, Rio de Janeiro, 20550-013, Brazil
| | - Mauro Martins Teixeira
- Department of Biochemistry and Immunology, Federal University of Minas Gerais, Belo Horizonte, 31270-901, Brazil
| | - Albanita Vianna
- Department of Pathology, State University of Rio de Janeiro, Rio de Janeiro, 22551-030, Brazil
| | - Alessandra Mattos Saliba
- Department of Microbiology, Immunology and Parasitology, State University of Rio de Janeiro, 20551-30 Rio de Janeiro, Brazil
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32
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da Cunha LG, Ferreira MF, de Moraes JA, Reis PA, Castro-Faria-Neto HC, Barja-Fidalgo C, Plotkowski MC, Saliba AM. ExoU-induced redox imbalance and oxidative stress in airway epithelial cells during Pseudomonas aeruginosa pneumosepsis. Med Microbiol Immunol 2015; 204:673-80. [PMID: 25904542 PMCID: PMC7100071 DOI: 10.1007/s00430-015-0418-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2014] [Accepted: 04/12/2015] [Indexed: 12/14/2022]
Abstract
ExoU is a potent proinflammatory toxin produced by Pseudomonas aeruginosa, a major agent of severe lung infection and sepsis. Because inflammation is usually associated with oxidative stress, we investigated the effect of ExoU on free radical production and antioxidant defense mechanisms during the course of P. aeruginosa infection. In an experimental model of acute pneumonia, ExoU accounted for increased lipid peroxidation in mice lungs as soon as 3 h after intratracheal instillation of PA103 P. aeruginosa strain. The contribution of airway cells to the generation of a redox imbalance was assessed by in vitro tests carried out with A549 airway epithelial cells. Cultures infected with the ExoU-producing PA103 P. aeruginosa strain produced significantly increased concentrations of lipid hydroperoxides, 8-isoprostane, reactive oxygen intermediates, peroxynitrite and nitric oxide (NO), when compared to cells infected with exoU-deficient mutants. Overproduction of NO by PA103-infected cells likely resulted from overexpression of both inducible and endothelial NO synthase isoforms. PA103 infection was also associated with a significantly increased activity of superoxide dismutase (SOD) and decreased levels of reduced glutathione (GSH), a major antioxidant compound. Our findings unveil another potential mechanism of tissue damage during infection by ExoU-producing P. aeruginosa strains.
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Affiliation(s)
- Luiz Gonzaga da Cunha
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade do Estado do Rio de Janeiro, Av. 28 de Setembro, 87, Fundos, 3° andar, Vila Isabel, Rio de Janeiro, RJ, 20.551-030, Brazil
| | - Miriam Francisca Ferreira
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade do Estado do Rio de Janeiro, Av. 28 de Setembro, 87, Fundos, 3° andar, Vila Isabel, Rio de Janeiro, RJ, 20.551-030, Brazil
| | - João Alfredo de Moraes
- Laboratório de Farmacologia Celular e Molecular, Departamento de Biologia Celular, IBRAG, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Patricia Alves Reis
- Laboratório de Imunofarmacologia, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, RJ, Brazil
| | | | - Christina Barja-Fidalgo
- Laboratório de Farmacologia Celular e Molecular, Departamento de Biologia Celular, IBRAG, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Maria-Cristina Plotkowski
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade do Estado do Rio de Janeiro, Av. 28 de Setembro, 87, Fundos, 3° andar, Vila Isabel, Rio de Janeiro, RJ, 20.551-030, Brazil
| | - Alessandra Mattos Saliba
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade do Estado do Rio de Janeiro, Av. 28 de Setembro, 87, Fundos, 3° andar, Vila Isabel, Rio de Janeiro, RJ, 20.551-030, Brazil.
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Sawa T, Shimizu M, Moriyama K, Wiener-Kronish JP. Association between Pseudomonas aeruginosa type III secretion, antibiotic resistance, and clinical outcome: a review. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2014; 18:668. [PMID: 25672496 PMCID: PMC4331484 DOI: 10.1186/s13054-014-0668-9] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Pseudomonas aeruginosa uses a complex type III secretion system to inject the toxins ExoS, ExoT, ExoU, and ExoY into the cytosol of target eukaryotic cells. This system is regulated by the exoenzyme S regulon and includes the transcriptional activator ExsA. Of the four toxins, ExoU is characterized as the major virulence factor responsible for alveolar epithelial injury in patients with P. aeruginosa pneumonia. Virulent strains of P. aeruginosa possess the exoU gene, whereas non-virulent strains lack this particular gene. The mechanism of virulence for the exoU+ genotype relies on the presence of a pathogenic gene cluster (PAPI-2) encoding exoU and its chaperone, spcU. The ExoU toxin has a patatin-like phospholipase domain in its N-terminal, exhibits phospholipase A2 activity, and requires a eukaryotic cell factor for activation. The C-terminal of ExoU has a ubiquitinylation mechanism of activation. This probably induces a structural change in enzymatic active sites required for phospholipase A2 activity. In P. aeruginosa clinical isolates, the exoU+ genotype correlates with a fluoroquinolone resistance phenotype. Additionally, poor clinical outcomes have been observed in patients with pneumonia caused by exoU+-fluoroquinolone-resistant isolates. Therefore, the potential exists to improve clinical outcomes in patients with P. aeruginosa pneumonia by identifying virulent and antimicrobial drug-resistant strains through exoU genotyping or ExoU protein phenotyping or both.
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Nobakht M Gh BF, Aliannejad R, Rezaei-Tavirani M, Taheri S, Oskouie AA. The metabolomics of airway diseases, including COPD, asthma and cystic fibrosis. Biomarkers 2014; 20:5-16. [PMID: 25403491 DOI: 10.3109/1354750x.2014.983167] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Chronic obstructive pulmonary disease (COPD), asthma and cystic fibrosis (CF) are characterized by airway obstruction and an inflammatory process. Reaching early diagnosis and discrimination of subtypes of these respiratory diseases are quite a challenging task than other chronic illnesses. Metabolomics is the study of metabolic pathways and the measurement of unique biochemical molecules generated in a living system. In the last decade, metabolomics has already proved to be useful for the characterization of several pathological conditions and offers promises as a clinical tool. In this article, we review the current state of the metabolomics of COPD, asthma and CF with a focus on the different methods and instrumentation being used for the discovery of biomarkers in research and translation into clinic as diagnostic aids for the choice of patient-specific therapies.
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Affiliation(s)
- B Fatemeh Nobakht M Gh
- Faculty of Paramedical Sciences, Proteomics Research Center, Shahid Beheshti University of Medical Sciences , Tehran , Iran
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Mallet de Lima CD, da Conceição Costa J, de Oliveira Lima Santos SA, Carvalho S, de Carvalho L, Albano RM, Teixeira MM, Plotkowski MCM, Saliba AM. Central role of PAFR signalling in ExoU-induced NF-κB activation. Cell Microbiol 2014; 16:1244-54. [PMID: 24612488 DOI: 10.1111/cmi.12280] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Revised: 01/30/2014] [Accepted: 02/14/2014] [Indexed: 01/01/2023]
Abstract
ExoU is an important virulence factor in acute Pseudomonas aeruginosa infections. Here, we unveiled the mechanisms of ExoU-driven NF-κB activation by using human airway cells and mice infected with P. aeruginosa strains. Several approaches showed that PAFR was crucially implicated in the activation of the canonical NF-κB pathway. Confocal microscopy of lungs from infected mice revealed that PAFR-dependent NF-κB activation occurred mainly in respiratory epithelial cells, and reduced p65 nuclear translocation was detected in mice PAFR-/- or treated with the PAFR antagonist WEB 2086. Several evidences showed that ExoU-induced NF-κB activation regulated PAFR expression. First, ExoU increased p65 occupation of PAFR promoter, as assessed by ChIP. Second, luciferase assays in cultures transfected with different plasmid constructs revealed that ExoU promoted p65 binding to the three κB sites in PAFR promoter. Third, treatment of cell cultures with the NF-κB inhibitor Bay 11-7082, or transfection with IκBα negative-dominant, significantly decreased PAFR mRNA. Finally, reduction in PAFR expression was observed in mice treated with Bay 11-7082 or WEB 2086 prior to infection. Together, our data demonstrate that ExoU activates NF-κB by PAFR signalling, which in turns enhances PAFR expression, highlighting an important mechanism of amplification of response to this P. aeruginosa toxin.
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Sullivan E, Bensman J, Lou M, Agnello M, Shriner K, Wong-Beringer A. Risk of developing pneumonia is enhanced by the combined traits of fluoroquinolone resistance and type III secretion virulence in respiratory isolates of Pseudomonas aeruginosa. Crit Care Med 2014; 42:48-56. [PMID: 23963124 DOI: 10.1097/ccm.0b013e318298a86f] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES To determine the differential association of host characteristics, antimicrobial resistance, and type III secretion system virulence of Pseudomonas aeruginosa isolates with respiratory syndromes in hospitalized adult patients. DESIGN Retrospective, cohort study. SETTING Community teaching hospital. PATIENTS Two hundred eighteen consecutive adult patients with respiratory culture positive for P. aeruginosa between January 2005 to January 2010. INTERVENTIONS Medical charts were reviewed to obtain demographic, laboratory, radiographic, and clinical information. Isolates were assayed by polymerase chain reaction for genes encoding the type III secretion system effectors (ExoU, ExoS, and PcrV) and for strain relatedness using randomly amplified polymorphic DNA analysis. Levofloxacin susceptibility was determined by broth microdilution. Patients were grouped by colonization, bronchitis, or pneumonia and were compared for differential risk of developing the clinical syndrome with respect to host and microbial characteristics. MEASUREMENTS AND MAIN RESULTS Half of the study cohort (54%, 117 of 218) had pneumonia, 32% (70 of 218) had bronchitis, and 14% (31 of 218) had colonization; in-hospital mortality was 35%, 11%, and 0%, respectively. Host factors strongly associated with pneumonia development were residence in long-term care facility, healthcare-associated acquisition of P. aeruginosa, higher Acute Physiology and Chronic Health Evaluation II score, presence of enteral feeding tube, mechanical ventilation, and recent history of pneumonia. Fluoroquinolone-resistant (57% vs 34%, 16%; p < 0.0001) and multidrug-resistant (36% vs 26%, 7%; p = 0.0045) strains were more likely to cause pneumonia than bronchitis or colonization, respectively. Analysis of host and microbial factors in a multivariate regression model yielded the combined traits of fluoroquinolone resistance and gene encoding the type III secretion system ExoU effector in P. aeruginosa as the single most significant predictor of pneumonia development. CONCLUSIONS These results suggest that fluoroquinolone-resistant phenotype in a type III secretion system exoU strain background contributes toward the pathogenesis of P. aeruginosa in pneumonia.
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Affiliation(s)
- Eva Sullivan
- 1Huntington Hospital, Pasadena, CA. 2University of Southern California, Los Angeles, CA
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Park AJ, Murphy K, Krieger JR, Brewer D, Taylor P, Habash M, Khursigara CM. A temporal examination of the planktonic and biofilm proteome of whole cell Pseudomonas aeruginosa PAO1 using quantitative mass spectrometry. Mol Cell Proteomics 2014; 13:1095-105. [PMID: 24532839 DOI: 10.1074/mcp.m113.033985] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Chronic polymicrobial lung infections are the chief complication in patients with cystic fibrosis. The dominant pathogen in late-stage disease is Pseudomonas aeruginosa, which forms recalcitrant, structured communities known as biofilms. Many aspects of biofilm biology are poorly understood; consequently, effective treatment of these infections is limited, and cystic fibrosis remains fatal. Here we combined in-solution protein digestion of triplicate growth-matched samples with a high-performance mass spectrometry platform to provide the most comprehensive proteomic dataset known to date for whole cell P. aeruginosa PAO1 grown in biofilm cultures. Our analysis included protein-protein interaction networks and PseudoCAP functional information for unique and significantly modulated proteins at three different time points. Secondary analysis of a subgroup of proteins using extracted ion currents validated the spectral counting data of 1884 high-confidence proteins. In this paper we demonstrate a greater representation of proteins related to metabolism, DNA stability, and molecular activity in planktonically grown P. aeruginosa PAO1. In addition, several virulence-related proteins were increased during planktonic growth, including multiple proteins encoded by the pyoverdine locus, uncharacterized proteins with sequence similarity to mammalian cell entry protein, and a member of the hemagglutinin family of adhesins, HecA. Conversely, biofilm samples contained an uncharacterized protein with sequence similarity to an adhesion protein with self-association characteristics (AidA). Increased levels of several phenazine biosynthetic proteins, an uncharacterized protein with sequence similarity to a metallo-beta-lactamase, and lower levels of the drug target gyrA support the putative characteristics of in situ P. aeruginosa infections, including competitive fitness and antibiotic resistance. This quantitative whole cell approach advances the existing P. aeruginosa subproteomes and provides a framework for identifying and studying entire pathways critical to biofilm biology in this model pathogenic organism. The identification of novel protein targets could contribute to the development of much needed antimicrobial therapies to treat the chronic infections found in patients with cystic fibrosis.
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Affiliation(s)
- Amber J Park
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
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Pohl CH, Kock JLF. Oxidized fatty acids as inter-kingdom signaling molecules. Molecules 2014; 19:1273-85. [PMID: 24448067 PMCID: PMC6270766 DOI: 10.3390/molecules19011273] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2013] [Revised: 01/16/2014] [Accepted: 01/16/2014] [Indexed: 12/27/2022] Open
Abstract
Oxylipins or oxidized fatty acids are a group of molecules found to play a role in signaling in many different cell types. These fatty acid derivatives have ancient evolutionary origins as signaling molecules and are ideal candidates for inter-kingdom communication. This review discusses examples of the ability of organisms from different kingdoms to “listen” and respond to oxylipin signals during interactions. The interactions that will be looked at are signaling between animals and plants; between animals and fungi; between animals and bacteria and between plants and fungi. This will aid in understanding these interactions, which often have implications in ecology, agriculture as well as human and animal health.
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Affiliation(s)
- Carolina H Pohl
- Department of Microbial, Biochemical and Food Biotechnology, University of the Free State, PO Box 339, Bloemfontein 9300, South Africa.
| | - Johan L F Kock
- Department of Microbial, Biochemical and Food Biotechnology, University of the Free State, PO Box 339, Bloemfontein 9300, South Africa.
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Agard M, Asakrah S, Morici LA. PGE(2) suppression of innate immunity during mucosal bacterial infection. Front Cell Infect Microbiol 2013; 3:45. [PMID: 23971009 PMCID: PMC3748320 DOI: 10.3389/fcimb.2013.00045] [Citation(s) in RCA: 104] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Accepted: 07/30/2013] [Indexed: 12/28/2022] Open
Abstract
Prostaglandin E2 (PGE2) is an important lipid mediator in inflammatory and immune responses during acute and chronic infections. Upon stimulation by various proinflammatory stimuli such as lipopolysaccharide (LPS), interleukin (IL)-1β, and tumor necrosis factor (TNF)-α, PGE2 synthesis is upregulated by the expression of cyclooxygenases. Biologically active PGE2 is then able to signal through four primary receptors to elicit a response. PGE2 is a critical molecule that regulates the activation, maturation, migration, and cytokine secretion of several immune cells, particularly those involved in innate immunity such as macrophages, neutrophils, natural killer cells, and dendritic cells. Both Gram-negative and Gram-positive bacteria can induce PGE2 synthesis to regulate immune responses during bacterial pathogenesis. This review will focus on PGE2 in innate immunity and how bacterial pathogens influence PGE2 production during enteric and pulmonary infections. The conserved ability of many bacterial pathogens to promote PGE2 responses during infection suggests a common signaling mechanism to deter protective pro-inflammatory immune responses. Inhibition of PGE2 production and signaling during infection may represent a therapeutic alternative to treat bacterial infections. Further study of the immunosuppressive effects of PGE2 on innate immunity will lead to a better understanding of potential therapeutic targets within the PGE2 pathway.
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Affiliation(s)
- Mallory Agard
- Department of Microbiology and Immunology, Tulane University School of Medicine New Orleans, LA 70119, USA
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Freitas C, Assis MC, Saliba AM, Morandi VM, Figueiredo CC, Pereira M, Plotkowski MC. The infection of microvascular endothelial cells with ExoU-producing Pseudomonas aeruginosa triggers the release of von Willebrand factor and platelet adhesion. Mem Inst Oswaldo Cruz 2013; 107:728-34. [PMID: 22990960 DOI: 10.1590/s0074-02762012000600004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Accepted: 04/09/2012] [Indexed: 01/12/2023] Open
Abstract
An increased plasma concentration of von Willebrand factor (vWF) is detected in individuals with many infectious diseases and is accepted as a marker of endothelium activation and prothrombotic condition. To determine whether ExoU, a Pseudomonas aeruginosa cytotoxin with proinflammatory activity, enhances the release of vWF, microvascular endothelial cells were infected with the ExoU-producing PA103 P. aeruginosa strain or an exoU-deficient mutant. Significantly increased vWF concentrations were detected in conditioned medium and subendothelial extracellular matrix from cultures infected with the wild-type bacteria, as determined by enzyme-linked immunoassays. PA103-infected cells also released higher concentrations of procoagulant microparticles containing increased amounts of membrane-associated vWF, as determined by flow cytometric analyses of cell culture supernatants. Both flow cytometry and confocal microscopy showed that increased amounts of vWF were associated with cytoplasmic membranes from cells infected with the ExoU-producing bacteria. PA103-infected cultures exposed to platelet suspensions exhibited increased percentages of cells with platelet adhesion. Because no modulation of the vWF mRNA levels was detected by reverse transcription-polymerase chain reaction assays in PA103-infected cells, ExoU is likely to have induced the release of vWF from cytoplasmic stores rather than vWF gene transcription. Such release is likely to modify the thromboresistance of microvascular endothelial cells.
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Affiliation(s)
- Carla Freitas
- Departamento de Microbiologia e Imunologia, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brasil
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Aurass P, Schlegel M, Metwally O, Harding CR, Schroeder GN, Frankel G, Flieger A. The Legionella pneumophila Dot/Icm-secreted effector PlcC/CegC1 together with PlcA and PlcB promotes virulence and belongs to a novel zinc metallophospholipase C family present in bacteria and fungi. J Biol Chem 2013; 288:11080-92. [PMID: 23457299 PMCID: PMC3630882 DOI: 10.1074/jbc.m112.426049] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Revised: 02/19/2013] [Indexed: 11/06/2022] Open
Abstract
Legionella pneumophila is a water-borne bacterium that causes pneumonia in humans. PlcA and PlcB are two previously defined L. pneumophila proteins with homology to the phosphatidylcholine-specific phospholipase C (PC-PLC) of Pseudomonas fluorescens. Additionally, we found that Lpg0012 shows similarity to PLCs and has been shown to be a Dot/Icm-injected effector, CegC1, which is designated here as PlcC. It remained unclear, however, whether these L. pneumophila proteins exhibit PLC activity. PlcC expressed in Escherichia coli hydrolyzed a broad phospholipid spectrum, including PC, phosphatidylglycerol (PG), and phosphatidylinositol. The addition of Zn(2+) ions activated, whereas EDTA inhibited, PlcC-derived PLC activity. Protein homology search revealed that the three Legionella enzymes and P. fluorescens PC-PLC share conserved domains also present in uncharacterized fungal proteins. Fifteen conserved amino acids were essential for enzyme activity as identified via PlcC mutagenesis. Analysis of defined L. pneumophila knock-out mutants indicated Lsp-dependent export of PG-hydrolyzing PLC activity. PlcA and PlcB exhibited PG-specific activity and contain a predicted Sec signal sequence. In line with the reported requirement of host cell contact for Dot/Icm-dependent effector translocation, PlcC showed cell-associated PC-specific PLC activity after bacterial growth in broth. A PLC triple mutant, but not single or double mutants, exhibited reduced host killing in a Galleria mellonella infection model, highlighting the importance of the three PLCs in pathogenesis. In summary, we describe here a novel Zn(2+)-dependent PLC family present in Legionella, Pseudomonas, and fungi with broad substrate preference and function in virulence.
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Affiliation(s)
- Philipp Aurass
- From the Division of Bacterial Infections, Robert Koch-Institut, Burgstrasse 37, 38855 Wernigerode, Germany and
| | - Maren Schlegel
- From the Division of Bacterial Infections, Robert Koch-Institut, Burgstrasse 37, 38855 Wernigerode, Germany and
| | - Omar Metwally
- From the Division of Bacterial Infections, Robert Koch-Institut, Burgstrasse 37, 38855 Wernigerode, Germany and
| | - Clare R. Harding
- the MRC Centre for Molecular Bacteriology and Infection, Division of Cell and Molecular Biology, Imperial College London, London SW7 2AZ, United Kingdom
| | - Gunnar N. Schroeder
- the MRC Centre for Molecular Bacteriology and Infection, Division of Cell and Molecular Biology, Imperial College London, London SW7 2AZ, United Kingdom
| | - Gad Frankel
- the MRC Centre for Molecular Bacteriology and Infection, Division of Cell and Molecular Biology, Imperial College London, London SW7 2AZ, United Kingdom
| | - Antje Flieger
- From the Division of Bacterial Infections, Robert Koch-Institut, Burgstrasse 37, 38855 Wernigerode, Germany and
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Kuhle K, Flieger A. Legionella phospholipases implicated in virulence. Curr Top Microbiol Immunol 2013; 376:175-209. [PMID: 23925490 DOI: 10.1007/82_2013_348] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Phospholipases are diverse enzymes produced in eukaryotic hosts and their bacterial pathogens. Several pathogen phospholipases have been identified as major virulence factors acting mainly in two different modes: on the one hand, they have the capability to destroy host membranes and on the other hand they are able to manipulate host signaling pathways. Reaction products of bacterial phospholipases may act as secondary messengers within the host and therefore influence inflammatory cascades and cellular processes, such as proliferation, migration, cytoskeletal changes as well as membrane traffic. The lung pathogen and intracellularly replicating bacterium Legionella pneumophila expresses a variety of phospholipases potentially involved in disease-promoting processes. So far, genes encoding 15 phospholipases A, three phospholipases C, and one phospholipase D have been identified. These cell-associated or secreted phospholipases may contribute to intracellular establishment, to egress of the pathogen from the host cell, and to the observed lung pathology. Due to the importance of phospholipase activities for host cell processes, it is conceivable that the pathogen enzymes may mimic or substitute host cell phospholipases to drive processes for the pathogen's benefit. The following chapter summarizes the current knowledge on the L. pneumophila phospholipases, especially their substrate specificity, localization, mode of secretion, and impact on host cells.
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Affiliation(s)
- Katja Kuhle
- FG 11 - Division of Enteropathogenic Bacteria and Legionella, Robert Koch-Institut, Burgstr. 37, 38855, Wernigerode, Germany
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de Lima CDM, Calegari-Silva TC, Pereira RMS, Santos SADOL, Lopes UG, Plotkowski MCM, Saliba AM. ExoU activates NF-κB and increases IL-8/KC secretion during Pseudomonas aeruginosa infection. PLoS One 2012; 7:e41772. [PMID: 22848596 PMCID: PMC3406076 DOI: 10.1371/journal.pone.0041772] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Accepted: 06/26/2012] [Indexed: 02/05/2023] Open
Abstract
ExoU, a Pseudomonas aeruginosa cytotoxin injected into host cytosol by type III secretion system, exhibits a potent proinflammatory activity that leads to a marked recruitment of neutrophils to infected tissues. To evaluate the mechanisms that account for neutrophil infiltration, we investigated the effect of ExoU on IL-8 secretion and NF-κB activation. We demonstrate that ExoU increases IL-8 mRNA and protein levels in P. aeruginosa-infected epithelial and endothelial cell lines. Also, ExoU induces the nuclear translocation of p65/p50 NF-κB transactivator heterodimer as well as NF-κB-dependent transcriptional activity. ChIP assays clearly revealed that ExoU promotes p65 binding to NF-κB site in IL-8 promoter and the treatment of cultures with the NF-κB inhibitor Bay 11-7082 led to a significant reduction in IL-8 mRNA levels and protein secretion induced by ExoU. These results were corroborated in a murine model of pneumonia that revealed a significant reduction in KC secretion and neutrophil infiltration in bronchoalveolar lavage when mice were treated with Bay 11-7082 before infection with an ExoU-producing strain. In conclusion, our data demonstrate that ExoU activates NF-κB, stimulating IL-8 expression and secretion during P. aeruginosa infection, and unveils a new mechanism triggered by this important virulence factor to interfere in host signaling pathways.
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Affiliation(s)
- Carolina Diettrich Mallet de Lima
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Teresa Cristina Calegari-Silva
- Laboratório de Parasitologia Molecular, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Renata Meirelles Santos Pereira
- Laboratório de Parasitologia Molecular, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | | | - Ulisses Gazos Lopes
- Laboratório de Parasitologia Molecular, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Maria-Cristina Maciel Plotkowski
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Alessandra Mattos Saliba
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
- * E-mail:
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Yang J, Eiserich JP, Cross CE, Morrissey BM, Hammock BD. Metabolomic profiling of regulatory lipid mediators in sputum from adult cystic fibrosis patients. Free Radic Biol Med 2012; 53:160-71. [PMID: 22580336 PMCID: PMC3412514 DOI: 10.1016/j.freeradbiomed.2012.05.001] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2011] [Revised: 04/29/2012] [Accepted: 05/01/2012] [Indexed: 01/22/2023]
Abstract
Retained respiratory tract (RT) secretions, infection, and exuberant inflammatory responses are core abnormalities in cystic fibrosis (CF) lung disease. Factors contributing to the destructive CF airway inflammatory processes remain incompletely characterized. The pro-oxidative inflammatory CF RT milieu is known to contain enzymatically and nonenzymatically produced regulatory lipid mediators, a panel of structurally defined oxidized metabolites of polyunsaturated fatty acids known to play a role in pathology related to inflammation. Using an extraction protocol that maximizes recoveries of sputum-spiked deuterated standards, coupled with an LC/MS/MS detection system, this study presents a metabolomic method to assess a broad spectrum of regulatory lipid mediators in freshly obtained sputum from CF patients. A broad range of both proinflammatory and anti-inflammatory lipid mediators was detected, including PGE2, PGD2, TXB2, LTB4, 6-trans-LTB4, 20-OH-LTB4, 20-COOH-LTB4, 20-HETE, 15-HETE, 11-HETE, 12-HETE, 8-HETE, 9-HETE, 5-HETE, EpETrEs, diols, resolvin E1, 15-deoxy-PGJ2, and LXA4. The vast majority of these oxylipins have not been reported previously in CF RT secretions. Whereas direct associations of individual proinflammatory lipid mediators with compromised lung function (FEV-1) were observed, the relationships were not robust. However, multiple statistical analyses revealed that the regulatory lipid mediators profile taken in aggregate proved to have a stronger association with lung function in relatively stable outpatient adult CF patients. Our data reveal a relative paucity of the anti-inflammatory lipid mediator lipoxin A4 in CF sputum. Patients displaying detectable levels of the anti-inflammatory lipid mediator resolvin E1 demonstrated a better lung function compared to those patients with undetectable levels. Our data suggest that comprehensive metabolomic profiling of regulatory lipid mediators in CF sputum should contribute to a better understanding of the molecular mechanisms underlying CF RT inflammatory pathobiology. Further studies are required to determine the extent to which nutritional or pharmacological interventions alter the regulatory lipid mediators profile of the CF RT and the impact of potential modulations of RT regulatory lipid mediators on the clinical progression of CF lung disease.
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Affiliation(s)
- Jun Yang
- Department of Entomology, University of California at Davis, Davis, CA 95616, USA
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Ramirez JC, Fleiszig SMJ, Sullivan AB, Tam C, Borazjani R, Evans DJ. Traversal of multilayered corneal epithelia by cytotoxic Pseudomonas aeruginosa requires the phospholipase domain of exoU. Invest Ophthalmol Vis Sci 2012; 53:448-53. [PMID: 22167094 DOI: 10.1167/iovs.11-8999] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
PURPOSE Pseudomonas aeruginosa isolates from microbial keratitis are invasive or cytotoxic toward mammalian cells, depending on their type III secreted toxins. Cytotoxic strains express ExoU, a phospholipase that contributes to corneal virulence. This study determined whether the ExoU phospholipase domain is required for P. aeruginosa traversal of the human corneal epithelium. METHODS P. aeruginosa traversal of airlifted, multilayered, human corneal epithelial cells was quantified in vitro up to 8 hours after apical inoculation with ∼10⁶ cfu of strain PA14, or an isogenic exoU mutant (PA14ΔexoU). In addition, PA14ΔexoU or its triple effector mutant PA14ΔexoUΔexoTΔexoY, were complemented with exoU (pUCPexoU), phospholipase-inactive exoU (pUCPexoUD344A), or control plasmid (pUCP18). Transepithelial resistance (TER) was measured (by epithelial volt ohmmeter), and cytotoxicity was determined by trypan blue staining. RESULTS PA14 traversed more efficiently than its exoU mutant at 4, 6, and 8 hours after inoculation (100-, 20-, and 8-fold, respectively; P < 0.05), but not at 2 hours. Cells exposed to PA14 lost TER to baseline (P < 0.05). Controls confirmed PA14 cytotoxicity toward these corneal epithelial cells that was absent with exoU mutants. Epithelial traversal, cytotoxicity, and lost TER were restored for PA14ΔexoU, or PA14ΔexoUΔexoTΔexoY, by complementation with pUCPexoU, but not by complementation with pUCPexoUD344A. CONCLUSIONS Traversal of multilayered corneal epithelia in vitro by cytotoxic P. aeruginosa requires ExoU with an active phospholipase domain. Correlative loss of TER with traversal by wild-type, or exoU-complemented, bacteria suggests involvement of epithelial cell death and/or lost tight junction integrity. However, traversal by exoU mutants without reduced TER suggests that additional mechanisms are also operative.
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Affiliation(s)
- Julio C Ramirez
- School of Optometry, University of California, Berkeley, California, USA
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Lang C, Flieger A. Characterisation of Legionella pneumophila phospholipases and their impact on host cells. Eur J Cell Biol 2011; 90:903-12. [DOI: 10.1016/j.ejcb.2010.12.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2010] [Revised: 12/08/2010] [Accepted: 12/13/2010] [Indexed: 01/16/2023] Open
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Pseudomonas aeruginosa toxin ExoU induces a PAF-dependent impairment of alveolar fibrin turnover secondary to enhanced activation of coagulation and increased expression of plasminogen activator inhibitor-1 in the course of mice pneumosepsis. Respir Res 2011; 12:104. [PMID: 21819560 PMCID: PMC3163543 DOI: 10.1186/1465-9921-12-104] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Accepted: 08/05/2011] [Indexed: 01/31/2023] Open
Abstract
Background ExoU, a Pseudomonas aeruginosa cytotoxin with phospholipase A2 activity, was shown to induce vascular hyperpermeability and thrombus formation in a murine model of pneumosepsis. In this study, we investigated the toxin ability to induce alterations in pulmonary fibrinolysis and the contribution of the platelet activating factor (PAF) in the ExoU-induced overexpression of plasminogen activator inhibitor-1 (PAI-1). Methods Mice were intratracheally instilled with the ExoU producing PA103 P. aeruginosa or its mutant with deletion of the exoU gene. After 24 h, animal bronchoalveolar lavage fluids (BALF) were analyzed and lung sections were submitted to fibrin and PAI-1 immunohistochemical localization. Supernatants from A549 airway epithelial cells and THP-1 macrophage cultures infected with both bacterial strains were also analyzed at 24 h post-infection. Results In PA103-infected mice, but not in control animals or in mice infected with the bacterial mutant, extensive fibrin deposition was detected in lung parenchyma and microvasculature whereas mice BALF exhibited elevated tissue factor-dependent procoagulant activity and PAI-1 concentration. ExoU-triggered PAI-1 overexpression was confirmed by immunohistochemistry. In in vitro assays, PA103-infected A549 cells exhibited overexpression of PAI-1 mRNA. Increased concentration of PAI-1 protein was detected in both A549 and THP-1 culture supernatants. Mice treatment with a PAF antagonist prior to PA103 infection reduced significantly PAI-1 concentrations in mice BALF. Similarly, A549 cell treatment with an antibody against PAF receptor significantly reduced PAI-1 mRNA expression and PAI-1 concentrations in cell supernatants, respectively. Conclusion ExoU was shown to induce disturbed fibrin turnover, secondary to enhanced procoagulant and antifibrinolytic activity during P. aeruginosa pneumosepsis, by a PAF-dependent mechanism. Besides its possible pathophysiological relevance, in vitro detection of exoU gene in bacterial clinical isolates warrants investigation as a predictor of outcome of patients with P. aeruginosa pneumonia/sepsis and as a marker to guide treatment strategies.
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Hurley BP, Pirzai W, Mumy KL, Gronert K, McCormick BA. Selective eicosanoid-generating capacity of cytoplasmic phospholipase A2 in Pseudomonas aeruginosa-infected epithelial cells. Am J Physiol Lung Cell Mol Physiol 2010; 300:L286-94. [PMID: 21097525 DOI: 10.1152/ajplung.00147.2010] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Airway neutrophil infiltration is a pathological hallmark observed in multiple lung diseases including pneumonia and cystic fibrosis. Bacterial pathogens such as Pseudomonas aeruginosa instigate neutrophil recruitment to the air space. Excessive accumulation of neutrophils in the lung often contributes to tissue destruction. Previous studies have unveiled hepoxilin A(3) as the key molecular signal driving neutrophils across epithelial barriers. The eicosanoid hepoxilin A(3) is a potent neutrophil chemoattractant produced by epithelial cells in response to infection with P. aeruginosa. The enzyme phospholipase A(2) liberates arachidonic acid from membrane phospholipids, the rate-limiting step in the synthesis of all eicosanoids, including hepoxilin A(3). Once generated, aracidonic acid is acted upon by multiple cyclooxygenases and lipoxygenases producing an array of functionally diverse eicosanoids. Although there are numerous phospholipase A(2) isoforms capable of generating arachidonic acid, the isoform most often associated with eicosanoid generation is cytoplasmic phospholipase A(2)α. In the current study, we observed that the cytoplasmic phospholipase A(2)α isoform is required for mediating P. aeruginosa-induced production of certain eicosanoids such as prostaglandin E(2). However, we found that neutrophil transepithelial migration induced by P. aeruginosa does not require cytoplasmic phospholipase A(2)α. Furthermore, P. aeruginosa-induced hepoxilin A(3) production persists despite cytoplasmic phospholipase A(2)α suppression and generation of the 12-lipoxygenase metabolite 12-HETE is actually enhanced in this context. These results suggest that alterative phospholipase A(2) isoforms are utilized to synthesize 12-lipoxygenase metabolites. The therapeutic implications of these findings are significant when considering anti-inflammatory therapies based on targeting eicosanoid synthesis pathways.
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Affiliation(s)
- Bryan P Hurley
- Mucosal Immunology, Massachusetts General Hospital, Charlestown, 02129, USA.
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Linkous A, Yazlovitskaya E. Cytosolic phospholipase A2 as a mediator of disease pathogenesis. Cell Microbiol 2010; 12:1369-77. [DOI: 10.1111/j.1462-5822.2010.01505.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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EXOU-INDUCED VASCULAR HYPERPERMEABILITY AND PLATELET ACTIVATION IN THE COURSE OF EXPERIMENTAL PSEUDOMONAS AERUGINOSA PNEUMOSEPSIS. Shock 2010; 33:315-21. [DOI: 10.1097/shk.0b013e3181b2b0f4] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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