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Reedy JL, Jensen KN, Crossen AJ, Basham KJ, Ward RA, Reardon CM, Harding HB, Hepworth OW, Simaku P, Kwaku GN, Tone K, Willment JA, Reid DM, Stappers MHT, Brown GD, Rajagopal J, Vyas JM. Fungal melanin suppresses airway epithelial chemokine secretion through blockade of calcium fluxing. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.03.28.534632. [PMID: 37034634 PMCID: PMC10081279 DOI: 10.1101/2023.03.28.534632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/22/2023]
Abstract
Respiratory infections caused by the human fungal pathogen Aspergillus fumigatus are a major cause of mortality for immunocompromised patients. Exposure to these pathogens occurs through inhalation, although the role of the respiratory epithelium in disease pathogenesis has not been fully defined. Employing a primary human airway epithelial model, we demonstrate that fungal melanins potently block the post-translational secretion of the chemokines CXCL1 and CXCL8 independent of transcription or the requirement of melanin to be phagocytosed, leading to a significant reduction in neutrophil recruitment to the apical airway both in vitro and in vivo . Aspergillus -derived melanin, a major constituent of the fungal cell wall, dampened airway epithelial chemokine secretion in response to fungi, bacteria, and exogenous cytokines. Furthermore, melanin muted pathogen-mediated calcium fluxing and hindered actin filamentation. Taken together, our results reveal a critical role for melanin interaction with airway epithelium in shaping the host response to fungal and bacterial pathogens.
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Hardy KS, Tuckey AN, Housley NA, Andrews J, Patel M, Al-Mehdi AB, Barrington RA, Cassel SL, Sutterwala FS, Audia JP. The Pseudomonas aeruginosa Type III Secretion System Exoenzyme Effector ExoU Induces Mitochondrial Damage in a Murine Bone Marrow-Derived Macrophage Infection Model. Infect Immun 2022; 90:e0047021. [PMID: 35130452 PMCID: PMC8929383 DOI: 10.1128/iai.00470-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 01/18/2022] [Indexed: 11/20/2022] Open
Abstract
Pseudomonas aeruginosa is a Gram-negative, opportunistic pathogen that causes nosocomial pneumonia, urinary tract infections, and bacteremia. A hallmark of P. aeruginosa pathogenesis is disruption of host cell function by the type III secretion system (T3SS) and its cognate exoenzyme effectors. The T3SS effector ExoU is phospholipase A2 (PLA2) that targets the host cell plasmalemmal membrane to induce cytolysis and is an important virulence factor that mediates immune avoidance. In addition, ExoU has been shown to subvert the host inflammatory response in a noncytolytic manner. In primary bone marrow-derived macrophages (BMDMs), P. aeruginosa infection is sensed by the nucleotide-binding domain containing leucine-rich repeats-like receptor 4 (NLRC4) inflammasome, which triggers caspase-1 activation and inflammation. ExoU transiently inhibits NLRC4 inflammasome-mediated activation of caspase-1 and its downstream target, interleukin 1β (IL-1β), to suppress activation of inflammation. In the present study, we sought to identify additional noncytolytic virulence functions for ExoU and discovered an unexpected association between ExoU, host mitochondria, and NLRC4. We show that infection of BMDMs with P. aeruginosa strains expressing ExoU elicited mitochondrial oxidative stress. In addition, mitochondria and mitochondrion-associated membrane fractions enriched from infected cells exhibited evidence of autophagy activation, indicative of damage. The observation that ExoU elicited mitochondrial stress and damage suggested that ExoU may also associate with mitochondria during infection. Indeed, ExoU phospholipase A2 enzymatic activity was present in enriched mitochondria and mitochondrion-associated membrane fractions isolated from P. aeruginosa-infected BMDMs. Intriguingly, enriched mitochondria and mitochondrion-associated membrane fractions isolated from infected Nlrc4 homozygous knockout BMDMs displayed significantly lower levels of ExoU enzyme activity, suggesting that NLRC4 plays a role in the ExoU-mitochondrion association. These observations prompted us to assay enriched mitochondria and mitochondrion-associated membrane fractions for NLRC4, caspase-1, and IL-1β. NLRC4 and pro-caspase-1 were detected in enriched mitochondria and mitochondrion-associated membrane fractions isolated from noninfected BMDMs, and active caspase-1 and active IL-1β were detected in response to P. aeruginosa infection. Interestingly, ExoU inhibited mitochondrion-associated caspase-1 and IL-1β activation. The implications of ExoU-mediated effects on mitochondria and the NLRC4 inflammasome during P. aeruginosa infection are discussed.
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Affiliation(s)
- Kierra S. Hardy
- Department of Microbiology and Immunology, University of South Alabama College of Medicine, Mobile, Alabama, USA
- Center for Lung Biology, University of South Alabama College of Medicine, Mobile, Alabama, USA
| | - Amanda N. Tuckey
- Department of Microbiology and Immunology, University of South Alabama College of Medicine, Mobile, Alabama, USA
- Center for Lung Biology, University of South Alabama College of Medicine, Mobile, Alabama, USA
| | - Nicole A. Housley
- Department of Microbiology and Immunology, University of South Alabama College of Medicine, Mobile, Alabama, USA
- Center for Lung Biology, University of South Alabama College of Medicine, Mobile, Alabama, USA
| | - Joel Andrews
- Mitchell Cancer Institute, University of South Alabama College of Medicine, Mobile, Alabama, USA
| | - Mita Patel
- Department of Pharmcology, University of South Alabama College of Medicine, Mobile, Alabama, USA
| | - Abu-Bakr Al-Mehdi
- Department of Pharmcology, University of South Alabama College of Medicine, Mobile, Alabama, USA
| | - Robert A. Barrington
- Department of Microbiology and Immunology, University of South Alabama College of Medicine, Mobile, Alabama, USA
- Center for Lung Biology, University of South Alabama College of Medicine, Mobile, Alabama, USA
| | - Suzanne L. Cassel
- Women’s Guild Lung Institute, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Fayyaz S. Sutterwala
- Women’s Guild Lung Institute, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Jonathon P. Audia
- Department of Microbiology and Immunology, University of South Alabama College of Medicine, Mobile, Alabama, USA
- Center for Lung Biology, University of South Alabama College of Medicine, Mobile, Alabama, USA
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3
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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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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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Pseudomonas aeruginosa Ventilator-Associated Pneumonia Rabbit Model for Preclinical Drug Development. Antimicrob Agents Chemother 2021; 65:e0272420. [PMID: 33972247 DOI: 10.1128/aac.02724-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Development and validation of large animal models of Pseudomonas aeruginosa ventilator-associated pneumonia are needed for testing new drug candidates in a manner that mimics how they will be used clinically. We developed a new model in which rabbits were ventilated with low tidal volume and challenged with P. aeruginosa to recapitulate hallmark clinical features of acute respiratory distress syndrome (ARDS): acute lung injury and inflammation, progressive decrease in arterial oxygen partial pressure to fractional inspired oxygen PaO2:FiO2, leukopenia, neutropenia, thrombocytopenia, hyperlactatemia, severe hypotension, bacterial dissemination from lung to other organs, multiorgan dysfunction, and ultimately death. We evaluated the predictive power of this rabbit model for antibiotic efficacy testing by determining whether a humanized dosing regimen of meropenem, a potent antipseudomonal β-lactam antibiotic, when administered with or without intensive care unit (ICU)-supportive care (fluid challenge and norepinephrine), could halt or reverse natural disease progression. Our humanized meropenem dosing regimen produced a plasma concentration-time profile in the rabbit model similar to those reported in patients with ventilator-associated bacterial pneumonia. In this rabbit model, treatment with humanized meropenem and ICU-supportive care achieved the highest level of survival, halted the worsening of ARDS biomarkers, and reversed lethal hypotension, although treatment with humanized meropenem alone also conferred some protection compared to treatment with placebo (saline) alone or placebo plus ICU-supportive care. In conclusion, this rabbit model could help predict whether an antibiotic will be efficacious for the treatment of human ventilator-associated pneumonia.
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Pseudomonas aeruginosa: An Audacious Pathogen with an Adaptable Arsenal of Virulence Factors. Int J Mol Sci 2021; 22:ijms22063128. [PMID: 33803907 PMCID: PMC8003266 DOI: 10.3390/ijms22063128] [Citation(s) in RCA: 194] [Impact Index Per Article: 64.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 03/16/2021] [Accepted: 03/16/2021] [Indexed: 12/13/2022] Open
Abstract
Pseudomonas aeruginosa is a dominant pathogen in people with cystic fibrosis (CF) contributing to morbidity and mortality. Its tremendous ability to adapt greatly facilitates its capacity to cause chronic infections. The adaptability and flexibility of the pathogen are afforded by the extensive number of virulence factors it has at its disposal, providing P. aeruginosa with the facility to tailor its response against the different stressors in the environment. A deep understanding of these virulence mechanisms is crucial for the design of therapeutic strategies and vaccines against this multi-resistant pathogen. Therefore, this review describes the main virulence factors of P. aeruginosa and the adaptations it undergoes to persist in hostile environments such as the CF respiratory tract. The very large P. aeruginosa genome (5 to 7 MB) contributes considerably to its adaptive capacity; consequently, genomic studies have provided significant insights into elucidating P. aeruginosa evolution and its interactions with the host throughout the course of infection.
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Adams W, Espicha T, Estipona J. Getting Your Neutrophil: Neutrophil Transepithelial Migration in the Lung. Infect Immun 2021; 89:IAI.00659-20. [PMID: 33526562 DOI: 10.1128/iai.00659-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Neutrophil transepithelial migration is a fundamental process that facilitates the rapid trafficking of neutrophils to inflammatory foci and occurs across a diverse range of tissues. For decades there has been widespread interest in understanding the mechanisms that drive this migratory process in response to different pathogens and organ systems. This has led to the successful integration of key findings on neutrophil transepithelial migration from the intestines, lungs, liver, genitourinary tract, and other tissues into a single, cohesive model. However, recent studies have identified organ specific differences in neutrophil transepithelial migration. These findings support a model where the tissue in concert with the pro-inflammatory stimuli dictate a unique collection of signals that drive neutrophil trafficking. This review focuses on the mechanisms that drive neutrophil transepithelial migration in response to microbial infection of a single organ, the lung. Herein we provide a detailed analysis of the adhesion molecules and chemoattractants that contribute to the recruitment of neutrophil into the airways. We also highlight important advances in experimental models for studying neutrophil transepithelial migration in the lung over the last decade.
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Affiliation(s)
- Walter Adams
- Department of Biological Sciences, San Jose State University, San Jose, CA 95192 USA
| | - Taylor Espicha
- Department of Biological Sciences, San Jose State University, San Jose, CA 95192 USA
| | - Janine Estipona
- Department of Biological Sciences, San Jose State University, San Jose, CA 95192 USA
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8
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Wille J, Teirlinck E, Sass A, Van Nieuwerburgh F, Kaever V, Braeckmans K, Coenye T. Does the mode of dispersion determine the properties of dispersed Pseudomonas aeruginosa biofilm cells? Int J Antimicrob Agents 2020; 56:106194. [PMID: 33039591 DOI: 10.1016/j.ijantimicag.2020.106194] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 06/30/2020] [Accepted: 09/26/2020] [Indexed: 10/23/2022]
Abstract
INTRODUCTION Actively dispersed Pseudomonas aeruginosa biofilm cells differ from planktonic cells, as they have a lower intracellular cyclic di-guanosine monophosphate (c-di-GMP) concentration and show increased virulence. In addition, the nature of the dispersion trigger has been shown to influence the antibiotic susceptibility of dispersed cells. However, properties of passively-dispersed cells, in which the dispersion trigger directly releases cells from the biofilm, have not been described. The present study determined c-di-GMP concentration, virulence in Galleria mellonella and antibiotic susceptibility of P. aeruginosa cells dispersed from biofilm using various triggers. MATERIALS AND METHODS P. aeruginosa biofilms grown in flow-cells were dispersed actively [exposure to the nitric oxide (NO)-donor sodium nitroprusside (SNP) or to glutamate] or passively [by stopping and restarting the flow or exposure to laser-induced vapor nanobubbles (VNB)], and properties of these dispersed cells were compared to those of spontaneously-dispersed cells. RESULTS The passively dispersed P. aeruginosa biofilm cells had significantly lower intracellular c-di-GMP levels than actively-dispersed cells. However, this did not result in differences in virulence in Galleria mellonella, nor in tobramycin and ciprofloxacin susceptibility. Passively-dispersed cells were more susceptible to colistin than actively- and spontaneously-dispersed cells. In cells dispersed by interrupting the flow, increased susceptibility to colistin was immediate, whereas this was delayed for VNB-dispersed cells. CONCLUSION Passively-dispersed P. aeruginosa biofilm cells have a decreased intracellular c-di-GMP concentration and an increased colistin susceptibility compared to actively-dispersed cells. No differences in virulence or susceptibility to tobramycin or colistin were observed.
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Affiliation(s)
- Jasper Wille
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
| | - Eline Teirlinck
- Laboratory of General Biochemistry and Physical Pharmacy, Ghent University, Ghent, Belgium; Centre for Nano- and Biophotonics, Ghent University, Ghent, Belgium
| | - Andrea Sass
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
| | | | - Volkhard Kaever
- Research Core Unit Metabolomics, Hannover Medical School, Hannover, Germany
| | - Kevin Braeckmans
- Laboratory of General Biochemistry and Physical Pharmacy, Ghent University, Ghent, Belgium; Centre for Nano- and Biophotonics, Ghent University, Ghent, Belgium
| | - Tom Coenye
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium.
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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: 4] [Impact Index Per Article: 1.0] [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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Aspergillus fumigatus Cell Wall Promotes Apical Airway Epithelial Recruitment of Human Neutrophils. Infect Immun 2020; 88:IAI.00813-19. [PMID: 31767773 DOI: 10.1128/iai.00813-19] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Accepted: 11/19/2019] [Indexed: 02/06/2023] Open
Abstract
Aspergillus fumigatus is a ubiquitous fungal pathogen capable of causing multiple pulmonary diseases, including invasive aspergillosis, chronic necrotizing aspergillosis, fungal colonization, and allergic bronchopulmonary aspergillosis. Intact mucociliary barrier function and early airway neutrophil responses are critical for clearing fungal conidia from the host airways prior to establishing disease. Following inhalation, Aspergillus conidia deposit in the small airways, where they are likely to make their initial host encounter with epithelial cells. Challenges in airway infection models have limited the ability to explore early steps in the interactions between A. fumigatus and the human airway epithelium. Here, we use inverted air-liquid interface cultures to demonstrate that the human airway epithelium responds to apical stimulation by A. fumigatus to promote the transepithelial migration of neutrophils from the basolateral membrane surface to the apical airway surface. Promoting epithelial transmigration with Aspergillus required prolonged exposure with live resting conidia. Swollen conidia did not expedite epithelial transmigration. Using A. fumigatus strains containing deletions of genes for cell wall components, we identified that deletion of the hydrophobic rodlet layer or dihydroxynaphthalene-melanin in the conidial cell wall amplified the epithelial transmigration of neutrophils, using primary human airway epithelium. Ultimately, we show that an as-yet-unidentified nonsecreted cell wall protein is required to promote the early epithelial transmigration of human neutrophils into the airspace in response to A. fumigatus Together, these data provide critical insight into the initial epithelial host response to Aspergillus.
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11
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Intestinal helminth infection enhances bacteria-induced recruitment of neutrophils to the airspace. Sci Rep 2019; 9:15703. [PMID: 31673002 PMCID: PMC6823376 DOI: 10.1038/s41598-019-51991-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 10/08/2019] [Indexed: 12/15/2022] Open
Abstract
Intestinal helminth infections elicit Th2-type immunity, which influences host immune responses to additional threats, such as allergens, metabolic disease, and other pathogens. Th2 immunity involves a shift of the CD4+ T-cell population from type-0 to type-2 (Th2) with increased abundance of interleukin (IL)-4 and IL-13. This study sought to investigate if existing gut-restricted intestinal helminth infections impact bacterial-induced acute airway neutrophil recruitment. C57BL/6 mice were divided into four groups: uninfected; helminth-Heligmosomoides polygyrus infected; Pseudomonas aeruginosa infected; and coinfected. Mice infected with H. polygyrus were incubated for 2 weeks, followed by P. aeruginosa intranasal inoculation. Bronchial alveolar lavage, blood, and lung samples were analyzed. Interestingly, infection with gut-restricted helminths resulted in immunological and structural changes in the lung. These changes include increased lung CD4+ T cells, increased Th2 cytokine expression, and airway goblet cell hyperplasia. Furthermore, coinfected mice exhibited significantly more airspace neutrophil infiltration at 6 hours following P. aeruginosa infection and exhibited an improved rate of survival compared with bacterial infected alone. These results suggest that chronic helminth infection of the intestines can influence and enhance acute airway neutrophil responses to P. aeruginosa infection.
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12
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Stevens JS, Gray MC, Morisseau C, Criss AK. Endocervical and Neutrophil Lipoxygenases Coordinate Neutrophil Transepithelial Migration to Neisseria gonorrhoeae. J Infect Dis 2019; 218:1663-1674. [PMID: 29905822 DOI: 10.1093/infdis/jiy347] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 06/06/2018] [Indexed: 12/13/2022] Open
Abstract
Background Infection with Neisseria gonorrhoeae (GC) is characterized by robust neutrophil influx that is insufficient to clear the bacteria. Sustained neutrophilic inflammation contributes to serious clinical sequelae that particularly affect women, including pelvic inflammatory disease and infertility. Methods We established a 3-component system using GC, End1 polarized human endocervical cells, and primary human neutrophils to investigate neutrophil transepithelial migration following infection. Results Neutrophil migration across endocervical monolayers increased with the infectious dose and required GC-epithelial cell contact. Epithelial protein kinase C, cytosolic phospholipase A2, 12R-lipoxygenase (LOX), and eLOX3 hepoxilin synthase were required for neutrophil transmigration to GC, and migration was abrogated by blocking the MRP2 efflux pump and by adding recombinant soluble epoxide hydrolase. These results are all consistent with epithelial cell production of the neutrophil chemoattractant hepoxilin A3 (HXA3). Neutrophil transmigration was also accompanied by increasing apical concentrations of leukotriene B4 (LTB4). Neutrophil 5-lipoxygenase and active BLT1 receptor were required for apical LTB4 and neutrophil migration. Conclusions Our data support a model in which GC-endocervical cell contact infection stimulates HXA3 production, driving neutrophil migration that is amplified by neutrophil-derived LTB4. Therapeutic targeting of these pathways could limit inflammation and deleterious clinical sequelae in women with gonorrhea.
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Affiliation(s)
- Jacqueline S Stevens
- Department of Microbiology, University of Virginia, Charlottesville.,Department of Immunology, University of Virginia, Charlottesville.,Department of Cancer Biology, University of Virginia, Charlottesville
| | - Mary C Gray
- Department of Microbiology, University of Virginia, Charlottesville.,Department of Immunology, University of Virginia, Charlottesville.,Department of Cancer Biology, University of Virginia, Charlottesville
| | - Christophe Morisseau
- Department of Entomology and Nematology, UC Davis Comprehensive Cancer Research Center, University of California, Davis
| | - Alison K Criss
- Department of Microbiology, University of Virginia, Charlottesville.,Department of Immunology, University of Virginia, Charlottesville.,Department of Cancer Biology, University of Virginia, Charlottesville
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13
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Song Y, Yang C, Chen G, Zhang Y, Seng Z, Cai Z, Zhang C, Yang L, Gan J, Liang H. Molecular insights into the master regulator CysB-mediated bacterial virulence in Pseudomonas aeruginosa. Mol Microbiol 2019; 111:1195-1210. [PMID: 30618115 DOI: 10.1111/mmi.14200] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/04/2019] [Indexed: 12/21/2022]
Abstract
Pseudomonas aeruginosa is a major pathogen that causes serious acute and chronic infections in humans. The type III secretion system (T3SS) is an important virulence factor that plays essential roles in acute infections. However, the regulatory mechanisms of T3SS are not fully understood. In this study, we found that the deletion of cysB reduced the T3SS gene expression and swarming motility but enhanced biofilm formation. In a mouse acute pneumonia model, mutation of cysB decreased the average bacterial load compared to that of the wild-type strain. Further experiments demonstrated that CysB contributed to the reduced T3SS gene expression and bacterial pathogenesis by directly regulating the sensor kinase RetS. We also performed crystallographic studies of PaCysB. The overall fold of PaCysB NTD domain is similar to other LysR superfamily proteins and structural superposition revealed one possible DNA-binding model for PaCysB. Structural comparison also revealed great flexibility of the PaCysB RD domain, which may play an important role in bending and transcriptional regulation of target DNA. Taken together, these results expand our current understanding of the complex regulatory networks of T3SS and RetS pathways. The crystal structure of CysB provides new insights for studying the function of its homologs in other bacterial species.
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Affiliation(s)
- Yaqin Song
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi'an, Shaanxi, 710069, China
| | - Chun Yang
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai, 200433, China
| | - Gukui Chen
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi'an, Shaanxi, 710069, China
| | - Yixi Zhang
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi'an, Shaanxi, 710069, China
| | - Zijing Seng
- School of Biological Sciences, Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, 639798, Singapore
| | - Zhao Cai
- School of Biological Sciences, Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, 639798, Singapore
| | - Chao Zhang
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi'an, Shaanxi, 710069, China
| | - Liang Yang
- School of Biological Sciences, Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, 639798, Singapore.,School of Medicine, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Jianhua Gan
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai, 200433, China
| | - Haihua Liang
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi'an, Shaanxi, 710069, China
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14
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Hasan S, Sebo P, Osicka R. A guide to polarized airway epithelial models for studies of host-pathogen interactions. FEBS J 2018; 285:4343-4358. [PMID: 29896776 DOI: 10.1111/febs.14582] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 05/21/2018] [Accepted: 06/11/2018] [Indexed: 11/28/2022]
Abstract
Mammalian lungs are organs exhibiting the cellular and spatial complexity required for gas exchange to support life. The respiratory epithelium internally lining the airways is susceptible to infections due to constant exposure to inhaled microbes. Biomedical research into respiratory bacterial infections in humans has been mostly carried out using small mammalian animal models or two-dimensional, submerged cultures of undifferentiated epithelial cells. These experimental model systems have considerable limitations due to host specificity of bacterial pathogens and lack of cellular and morphological complexity. This review describes the in vitro differentiated and polarized airway epithelial cells of human origin that are used as a model to study respiratory bacterial infections. Overall, these models recapitulate key aspects of the complexity observed in vivo and can help in elucidating the molecular details of disease processes observed during respiratory bacterial infections.
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Affiliation(s)
- Shakir Hasan
- Institute of Microbiology of the CAS, v. v. i., Prague, Czech Republic
| | - Peter Sebo
- Institute of Microbiology of the CAS, v. v. i., Prague, Czech Republic
| | - Radim Osicka
- Institute of Microbiology of the CAS, v. v. i., Prague, Czech Republic
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15
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Drenkard E, Hibbler RM, Gutu DA, Eaton AD, Silverio AL, Ausubel FM, Hurley BP, Yonker LM. Replication of the Ordered, Nonredundant Library of Pseudomonas aeruginosa strain PA14 Transposon Insertion Mutants. J Vis Exp 2018. [PMID: 29781996 DOI: 10.3791/57298] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Pseudomonas aeruginosa is a phenotypically and genotypically diverse and adaptable Gram-negative bacterium ubiquitous in human environments. P. aeruginosa is able to form biofilms, develop antibiotic resistance, produce virulence factors, and rapidly evolve in the course of a chronic infection. Thus P. aeruginosa can cause both acute and chronic, difficult to treat infections, resulting in significant morbidity in certain patient populations. P. aeruginosa strain PA14 is a human clinical isolate with a conserved genome structure that infects a variety of mammalian and nonvertebrate hosts making PA14 an attractive strain for studying this pathogen. In 2006, a nonredundant transposon insertion mutant library containing 5,459 mutants corresponding to 4,596 predicted PA14 genes was generated. Since then, distribution of the PA14 library has allowed the research community to better understand the function of individual genes and complex pathways of P. aeruginosa. Maintenance of library integrity through the replication process requires proper handling and precise techniques. To that end, this manuscript presents protocols that describe in detail the steps involved in library replication, library quality control and proper storage of individual mutants.
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Affiliation(s)
- Eliana Drenkard
- Department of Pediatrics, Mucosal Immunology and Biology Research Center, Massachusetts General Hospital
| | - Rhianna M Hibbler
- Department of Pediatrics, Mucosal Immunology and Biology Research Center, Massachusetts General Hospital
| | - D Alina Gutu
- Department of Molecular Biology, Massachusetts General Hospital
| | - Alexander D Eaton
- Department of Pediatrics, Mucosal Immunology and Biology Research Center, Massachusetts General Hospital
| | - Amy L Silverio
- Department of Pediatrics, Mucosal Immunology and Biology Research Center, Massachusetts General Hospital
| | - Frederick M Ausubel
- Department of Molecular Biology, Massachusetts General Hospital; Department of Genetics, Harvard Medical School
| | - Bryan P Hurley
- Department of Pediatrics, Mucosal Immunology and Biology Research Center, Massachusetts General Hospital; Department of Pediatrics, Harvard Medical School
| | - Lael M Yonker
- Department of Pediatrics, Mucosal Immunology and Biology Research Center, Massachusetts General Hospital; Department of Pediatrics, Harvard Medical School;
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