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Kizaki H, Omae Y, Tabuchi F, Saito Y, Sekimizu K, Kaito C. Cell-Surface Phenol Soluble Modulins Regulate Staphylococcus aureus Colony Spreading. PLoS One 2016; 11:e0164523. [PMID: 27723838 PMCID: PMC5056675 DOI: 10.1371/journal.pone.0164523] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 09/27/2016] [Indexed: 11/18/2022] Open
Abstract
Staphylococcus aureus produces phenol-soluble modulins (PSMs), which are amphipathic small peptides with lytic activity against mammalian cells. We previously reported that PSMα1-4 stimulate S. aureus colony spreading, the phenomenon of S. aureus colony expansion on the surface of soft agar plates, whereas δ-toxin (Hld, PSMγ) inhibits colony-spreading activity. In this study, we revealed the underlying mechanism of the opposing effects of PSMα1-4 and δ-toxin in S. aureus colony spreading. PSMα1-4 and δ-toxin are abundant on the S. aureus cell surface, and account for 18% and 8.5% of the total amount of PSMα1-4 and δ-toxin, respectively, in S. aureus overnight cultures. Knockout of PSMα1-4 did not affect the amount of cell surface δ-toxin. In contrast, knockout of δ-toxin increased the amount of cell surface PSMα1-4, and decreased the amount of culture supernatant PSMα1-4. The δ-toxin inhibited PSMα3 and PSMα2 binding to the S. aureus cell surface in vitro. A double knockout strain of PSMα1-4 and δ-toxin exhibited decreased colony spreading compared with the parent strain. Expression of cell surface PSMα1-4, but not culture supernatant PSMα1-4, restored the colony-spreading activity of the PSMα1-4/δ-toxin double knockout strain. Expression of δ-toxin on the cell surface or in the culture supernatant did not restore the colony-spreading activity of the PSMα1-4/δ-toxin double knockout strain. These findings suggest that cell surface PSMα1-4 promote S. aureus colony spreading, whereas δ-toxin suppresses colony-spreading activity by inhibiting PSMα1-4 binding to the S. aureus cell surface.
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Affiliation(s)
- Hayato Kizaki
- Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Yosuke Omae
- Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Fumiaki Tabuchi
- Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Yuki Saito
- Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Kazuhisa Sekimizu
- Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Chikara Kaito
- Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- * E-mail:
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Blättner S, Das S, Paprotka K, Eilers U, Krischke M, Kretschmer D, Remmele CW, Dittrich M, Müller T, Schuelein-Voelk C, Hertlein T, Mueller MJ, Huettel B, Reinhardt R, Ohlsen K, Rudel T, Fraunholz MJ. Staphylococcus aureus Exploits a Non-ribosomal Cyclic Dipeptide to Modulate Survival within Epithelial Cells and Phagocytes. PLoS Pathog 2016; 12:e1005857. [PMID: 27632173 PMCID: PMC5025175 DOI: 10.1371/journal.ppat.1005857] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 08/10/2016] [Indexed: 12/21/2022] Open
Abstract
Community-acquired (CA) Staphylococcus aureus cause various diseases even in healthy individuals. Enhanced virulence of CA-strains is partly attributed to increased production of toxins such as phenol-soluble modulins (PSM). The pathogen is internalized efficiently by mammalian host cells and intracellular S. aureus has recently been shown to contribute to disease. Upon internalization, cytotoxic S. aureus strains can disrupt phagosomal membranes and kill host cells in a PSM-dependent manner. However, PSM are not sufficient for these processes. Here we screened for factors required for intracellular S. aureus virulence. We infected escape reporter host cells with strains from an established transposon mutant library and detected phagosomal escape rates using automated microscopy. We thereby, among other factors, identified a non-ribosomal peptide synthetase (NRPS) to be required for efficient phagosomal escape and intracellular survival of S. aureus as well as induction of host cell death. By genetic complementation as well as supplementation with the synthetic NRPS product, the cyclic dipeptide phevalin, wild-type phenotypes were restored. We further demonstrate that the NRPS is contributing to virulence in a mouse pneumonia model. Together, our data illustrate a hitherto unrecognized function of the S. aureus NRPS and its dipeptide product during S. aureus infection.
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Affiliation(s)
- Sebastian Blättner
- Biocenter, Chair of Microbiology, University of Würzburg, Würzburg, Germany
| | - Sudip Das
- Biocenter, Chair of Microbiology, University of Würzburg, Würzburg, Germany
| | - Kerstin Paprotka
- Biocenter, Chair of Microbiology, University of Würzburg, Würzburg, Germany
| | - Ursula Eilers
- Core Unit Functional Genomics, University of Würzburg, Würzburg, Germany
| | - Markus Krischke
- Biocenter, Chair of Pharmaceutical Biology, University of Würzburg, Würzburg, Germany
| | - Dorothee Kretschmer
- Department of Infection Biology, Interfaculty Institute for Microbiology and Infection Medicine Tübingen (IMIT), University Tübingen, Tübingen, Germany
| | | | - Marcus Dittrich
- Biocenter, Chair of Bioinformatics, University of Würzburg, Würzburg, Germany
- Institute of Human Genetics, University of Würzburg, Würzburg, Germany
| | - Tobias Müller
- Biocenter, Chair of Bioinformatics, University of Würzburg, Würzburg, Germany
| | | | - Tobias Hertlein
- Institute for Molecular Infection Biology, University of Würzburg, Würzburg, Germany
| | - Martin J. Mueller
- Biocenter, Chair of Pharmaceutical Biology, University of Würzburg, Würzburg, Germany
| | | | | | - Knut Ohlsen
- Institute for Molecular Infection Biology, University of Würzburg, Würzburg, Germany
| | - Thomas Rudel
- Biocenter, Chair of Microbiology, University of Würzburg, Würzburg, Germany
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Impact of sarA and Phenol-Soluble Modulins on the Pathogenesis of Osteomyelitis in Diverse Clinical Isolates of Staphylococcus aureus. Infect Immun 2016; 84:2586-94. [PMID: 27354444 DOI: 10.1128/iai.00152-16] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 06/18/2016] [Indexed: 12/21/2022] Open
Abstract
We used a murine model of acute, posttraumatic osteomyelitis to evaluate the virulence of two divergent Staphylococcus aureus clinical isolates (the USA300 strain LAC and the USA200 strain UAMS-1) and their isogenic sarA mutants. The results confirmed that both strains caused comparable degrees of osteolysis and reactive new bone formation in the acute phase of osteomyelitis. Conditioned medium (CM) from stationary-phase cultures of both strains was cytotoxic to cells of established cell lines (MC3TC-E1 and RAW 264.7 cells), primary murine calvarial osteoblasts, and bone marrow-derived osteoclasts. Both the cytotoxicity of CM and the reactive changes in bone were significantly reduced in the isogenic sarA mutants. These results confirm that sarA is required for the production and/or accumulation of extracellular virulence factors that limit osteoblast and osteoclast viability and that thereby promote bone destruction and reactive bone formation during the acute phase of S. aureus osteomyelitis. Proteomic analysis confirmed the reduced accumulation of multiple extracellular proteins in the LAC and UAMS-1 sarA mutants. Included among these were the alpha class of phenol-soluble modulins (PSMs), which were previously implicated as important determinants of osteoblast cytotoxicity and bone destruction and repair processes in osteomyelitis. Mutation of the corresponding operon reduced the cytotoxicity of CM from both UAMS-1 and LAC cultures for osteoblasts and osteoclasts. It also significantly reduced both reactive bone formation and cortical bone destruction by CM from LAC cultures. However, this was not true for CM from cultures of a UAMS-1 psmα mutant, thereby suggesting the involvement of additional virulence factors in such strains that remain to be identified.
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Li L, Pian Y, Chen S, Hao H, Zheng Y, Zhu L, Xu B, Liu K, Li M, Jiang H, Jiang Y. Phenol-soluble modulin α4 mediates Staphylococcus aureus-associated vascular leakage by stimulating heparin-binding protein release from neutrophils. Sci Rep 2016; 6:29373. [PMID: 27383625 PMCID: PMC4935938 DOI: 10.1038/srep29373] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 06/16/2016] [Indexed: 11/09/2022] Open
Abstract
Vascular leakage frequently occurs in patients with severe Staphylococcus aureus infection. However, the mechanism underlying S. aureus infection-induced vascular leakage remains unclear. Here, we identified the S. aureus virulence factor phenol-soluble modulin (PSM)α4 from the culture supernatant of strain USA300 as a stimulator of heparin-binding protein (HBP) release from polymorphonuclear neutrophils (PMNs) and demonstrated that PSMα4-induced HBP release from PMNs leads to vascular leakage. PSMα4 appeared less cytolytic than PSMα1-3 and was insensitive to lipoproteins; it significantly increased myeloperoxidase and elastase release from PMNs and cell surface CD63 expression in PMNs. PSMα4-induced HBP release required formyl peptide receptor 2 (FPR2) and phosphoinositide 3-kinase (PI3K) and depended on Ca(2+) influx and cytoskeleton rearrangement. Thus, PSMα4 may stimulate HBP release by activating FPR2 and PI3K to initiate PMN degranulation. PSMα4-induced HBP release from PMNs increased endothelial cell monolayer permeability in vitro and induced vascular leakage in mice. This novel function of PSMα4 may contribute to the pathogenesis of S. aureus and may be a potential therapeutic target.
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Affiliation(s)
- Lin Li
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing, China
| | - Yaya Pian
- Key Laboratory of infection and immunity, Institute of Biophysics, Chinese Academy of Science, Beijing 100101, China
| | - Shaolong Chen
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing, China
| | - Huaijie Hao
- Institution of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Yuling Zheng
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing, China
| | - Li Zhu
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Biotechnology, Beijing 100071, China
| | - Bin Xu
- National Center of Biomedical Analysis, Beijing, China
| | - Keke Liu
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing, China
| | - Min Li
- Department of laboratory medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Hua Jiang
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing, China
| | - Yongqiang Jiang
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing, China
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55
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Surewaard BGJ, Deniset JF, Zemp FJ, Amrein M, Otto M, Conly J, Omri A, Yates RM, Kubes P. Identification and treatment of the Staphylococcus aureus reservoir in vivo. J Exp Med 2016; 213:1141-51. [PMID: 27325887 PMCID: PMC4925027 DOI: 10.1084/jem.20160334] [Citation(s) in RCA: 148] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 04/29/2016] [Indexed: 02/05/2023] Open
Abstract
Kubes et al. show that methicillin-resistant Staphylococcus aureus (MRSA) survive and proliferate inside Kupffer cells. Intracellular MRSA is resistant to neutrophil-killing and antibiotics treatment and, when released into the circulation, can infect other organs. Methicillin-resistant Staphylococcus aureus (MRSA) bacteremia is reaching epidemic proportions causing morbidity, mortality, and chronic disease due to relapses, suggesting an intracellular reservoir. Using spinning-disk confocal intravital microscopy to track MRSA-GFP in vivo, we identified that within minutes after intravenous infection MRSA is primarily sequestered and killed by intravascular Kupffer cells (KCs) in the liver. However, a minority of the Staphylococci overcome the KC’s antimicrobial defenses. These bacteria survive and proliferate for many days within this intracellular niche, where they remain undetected by recruited neutrophils. Over time, the KCs lyse, releasing bacteria into the circulation, enabling dissemination to other organs such as the kidneys. Vancomycin, the antibiotic of choice to treat MRSA bacteremia, could not penetrate the KCs to eradicate intracellular MRSA. However, based on the intravascular location of these specific macrophages, we designed a liposomal formulation of vancomycin that is efficiently taken up by KCs and diminished the intracellular MRSA. Targeting the source of the reservoir dramatically protected the liver but also dissemination to other organs, and prevented mortality. This vancomycin formulation strategy could help treat patients with Staphylococcal bacteremia without a need for novel antibiotics by targeting the previously inaccessible intracellular reservoir in KCs.
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Affiliation(s)
- Bas G J Surewaard
- Snyder Institute for Chronic Diseases, University of Calgary, Calgary AB T2N 1N4, Alberta, Canada Department of Medical Microbiology, University Medical Centre, 3584 CX Utrecht, the Netherlands
| | - Justin F Deniset
- Snyder Institute for Chronic Diseases, University of Calgary, Calgary AB T2N 1N4, Alberta, Canada
| | - Franz J Zemp
- Snyder Institute for Chronic Diseases, University of Calgary, Calgary AB T2N 1N4, Alberta, Canada
| | - Matthias Amrein
- Department of Cell Biology and Anatomy, University of Calgary, Calgary AB T2N 1N4, Alberta, Canada
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - John Conly
- Snyder Institute for Chronic Diseases, University of Calgary, Calgary AB T2N 1N4, Alberta, Canada Department of Medicine, Cumming School of Medicine, University of Calgary, Calgary AB T2N 1N4, Alberta, Canada Department of Pathology and Laboratory Medicine, University of Calgary, Calgary AB T2N 1N4, Alberta, Canada Department of Microbiology, Infectious Diseases and Immunology, University of Calgary, Calgary AB T2N 1N4, Alberta, Canada
| | - Abdelwahab Omri
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury ON P3E 2C6, Ontario, Canada
| | - Robin M Yates
- Snyder Institute for Chronic Diseases, University of Calgary, Calgary AB T2N 1N4, Alberta, Canada Department of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, Calgary AB T2N 1N4, Alberta, Canada
| | - Paul Kubes
- Snyder Institute for Chronic Diseases, University of Calgary, Calgary AB T2N 1N4, Alberta, Canada Department of Physiology and Pharmacology, University of Calgary, Calgary AB T2N 1N4, Alberta, Canada
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56
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Kavanaugh JS, Horswill AR. Impact of Environmental Cues on Staphylococcal Quorum Sensing and Biofilm Development. J Biol Chem 2016; 291:12556-12564. [PMID: 27129223 DOI: 10.1074/jbc.r116.722710] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Staphylococci are commensal bacteria that colonize the epithelial surfaces of humans and many other mammals. These bacteria can also attach to implanted medical devices and develop surface-associated biofilm communities that resist clearance by host defenses and available chemotherapies. These communities are often associated with persistent staphylococcal infections that place a tremendous burden on the healthcare system. Understanding the regulatory program that controls staphylococcal biofilm development, as well as the environmental conditions that modulate this program, has been a focal point of research in recent years. A central regulator controlling biofilm development is a peptide quorum-sensing system, also called the accessory gene regulator or agr system. In the opportunistic pathogen Staphylococcus aureus, the agr system controls production of exo-toxins and exo-enzymes essential for causing infections, and simultaneously, it modulates the ability of this pathogen to attach to surfaces and develop a biofilm, or to disperse from the biofilm state. In this review, we explore advances on the interconnections between the agr quorum-sensing system and biofilm mechanisms, and topics covered include recent findings on how different environmental conditions influence quorum sensing, the impact on biofilm development, and ongoing questions and challenges in the field. As our understanding of the quorum sensing and biofilm interconnection advances, there are growing opportunities to take advantage of this knowledge and develop therapeutic approaches to control staphylococcal infections.
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Affiliation(s)
- Jeffrey S Kavanaugh
- Department of Microbiology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - Alexander R Horswill
- Department of Microbiology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242.
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de Breij A, Riool M, Kwakman PHS, de Boer L, Cordfunke RA, Drijfhout JW, Cohen O, Emanuel N, Zaat SAJ, Nibbering PH, Moriarty TF. Prevention of Staphylococcus aureus biomaterial-associated infections using a polymer-lipid coating containing the antimicrobial peptide OP-145. J Control Release 2015; 222:1-8. [PMID: 26658071 DOI: 10.1016/j.jconrel.2015.12.003] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 11/27/2015] [Accepted: 12/01/2015] [Indexed: 10/22/2022]
Abstract
The scarcity of current antibiotic-based strategies to prevent biomaterial-associated infections (BAI) and their risk of resistance development prompted us to develop a novel antimicrobial implant-coating to prevent Staphylococcus aureus-induced BAI. We incorporated the antimicrobial peptide OP-145 into a Polymer-Lipid Encapsulation MatriX (PLEX)-coating to obtain high peptide levels for prolonged periods at the implant-tissue interphase. We first confirmed that OP-145 was highly effective in killing S. aureus and inhibiting biofilm formation in vitro. OP-145 injected along S. aureus-inoculated implants in mice significantly reduced the number of culture-positive implants. OP-145 was released from the PLEX coating in a controlled zero-order kinetic rate after an initial 55%-burst release and displayed bactericidal activity in vitro. In a rabbit intramedullary nail-related infection model, 67% of rabbits with PLEX-OP-145-coated nails had culture-negative nails after 28days compared to 29% of rabbits with uncoated nails. In rabbits with PLEX-OP-145-coated nails, bone and soft tissue samples were culture-negative in 67% and 80%, respectively, whereas all bone samples and 71% of the soft tissue samples of rabbits with uncoated nails were infected. Together, PLEX-OP-145 coatings, of which both compounds have already been found safe in man, can prevent implant colonization and S. aureus-induced BAIs.
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Affiliation(s)
- A de Breij
- Dept. of Infectious Diseases, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, P.O. Box 9600, RC Leiden, The Netherlands.
| | - M Riool
- Dept. of Medical Microbiology, Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
| | - P H S Kwakman
- Dept. of Medical Microbiology, Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
| | - L de Boer
- Dept. of Medical Microbiology, Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
| | - R A Cordfunke
- Dept. of Immunohematology and Blood Transfusion, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, P.O. Box 9600 RC Leiden, the Netherlands
| | - J W Drijfhout
- Dept. of Immunohematology and Blood Transfusion, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, P.O. Box 9600 RC Leiden, the Netherlands
| | - O Cohen
- PolyPid Ltd., 18 Hasivim, St. Petach-Tikva 4959376, Israel
| | - N Emanuel
- PolyPid Ltd., 18 Hasivim, St. Petach-Tikva 4959376, Israel
| | - S A J Zaat
- Dept. of Medical Microbiology, Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
| | - P H Nibbering
- Dept. of Infectious Diseases, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, P.O. Box 9600, RC Leiden, The Netherlands
| | - T F Moriarty
- AO Research Institute Davos, AO Foundation, Clavadelerstrasse 8 Davos Platz, CH7270 Davos, Switzerland
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58
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Flannagan RS, Heit B, Heinrichs DE. Antimicrobial Mechanisms of Macrophages and the Immune Evasion Strategies of Staphylococcus aureus. Pathogens 2015; 4:826-68. [PMID: 26633519 PMCID: PMC4693167 DOI: 10.3390/pathogens4040826] [Citation(s) in RCA: 128] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 11/17/2015] [Accepted: 11/24/2015] [Indexed: 12/21/2022] Open
Abstract
Habitually professional phagocytes, including macrophages, eradicate microbial invaders from the human body without overt signs of infection. Despite this, there exist select bacteria that are professional pathogens, causing significant morbidity and mortality across the globe and Staphylococcus aureus is no exception. S. aureus is a highly successful pathogen that can infect virtually every tissue that comprises the human body causing a broad spectrum of diseases. The profound pathogenic capacity of S. aureus can be attributed, in part, to its ability to elaborate a profusion of bacterial effectors that circumvent host immunity. Macrophages are important professional phagocytes that contribute to both the innate and adaptive immune response, however from in vitro and in vivo studies, it is evident that they fail to eradicate S. aureus. This review provides an overview of the antimicrobial mechanisms employed by macrophages to combat bacteria and describes the immune evasion strategies and some representative effectors that enable S. aureus to evade macrophage-mediated killing.
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Affiliation(s)
- Ronald S Flannagan
- Department of Microbiology and Immunology, the University of Western Ontario, London, ON N6A 5C1, Canada.
| | - Bryan Heit
- Department of Microbiology and Immunology, the University of Western Ontario, London, ON N6A 5C1, Canada.
- Centre for Human Immunology, the University of Western Ontario, London, ON N6A 5C1, Canada.
| | - David E Heinrichs
- Department of Microbiology and Immunology, the University of Western Ontario, London, ON N6A 5C1, Canada.
- Centre for Human Immunology, the University of Western Ontario, London, ON N6A 5C1, Canada.
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59
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Manifold-Wheeler BC, Elmore BO, Triplett KD, Castleman MJ, Otto M, Hall PR. Serum Lipoproteins Are Critical for Pulmonary Innate Defense against Staphylococcus aureus Quorum Sensing. THE JOURNAL OF IMMUNOLOGY 2015; 196:328-35. [PMID: 26608923 DOI: 10.4049/jimmunol.1501835] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Accepted: 10/30/2015] [Indexed: 01/12/2023]
Abstract
Hyperlipidemia has been extensively studied in the context of atherosclerosis, whereas the potential health consequences of the opposite extreme, hypolipidemia, remain largely uninvestigated. Circulating lipoproteins are essential carriers of insoluble lipid molecules and are increasingly recognized as innate immune effectors. Importantly, severe hypolipidemia, which may occur with trauma or critical illness, is clinically associated with bacterial pneumonia. To test the hypothesis that circulating lipoproteins are essential for optimal host innate defense in the lung, we used lipoprotein-deficient mice and a mouse model of Staphylococcus aureus pneumonia in which invasive infection requires virulence factor expression controlled by the accessory gene regulator (agr) operon. Activation of agr and subsequent virulence factor expression is inhibited by apolipoprotein B, the structural protein of low-density lipoprotein, which binds and sequesters the secreted agr-signaling peptide (AIP). In this article, we report that lipoprotein deficiency impairs early pulmonary innate defense against S. aureus quorum-sensing-dependent pathogenesis. Specifically, apolipoprotein B levels in the lung early postinfection are significantly reduced with lipoprotein deficiency, coinciding with impaired host control of S. aureus agr-signaling and increased agr-dependent morbidity (weight loss) and inflammation. Given that lipoproteins also inhibit LTA- and LPS-mediated inflammation, these results suggest that hypolipidemia may broadly impact posttrauma pneumonia susceptibility to both Gram-positive and -negative pathogens. Together with previous reports demonstrating that hyperlipidemia also impairs lung innate defense, these results suggest that maintenance of normal serum lipoprotein levels is necessary for optimal host innate defense in the lung.
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Affiliation(s)
- Brett C Manifold-Wheeler
- Department of Pharmaceutical Sciences, University of New Mexico College of Pharmacy, Albuquerque, NM 87131; and
| | - Bradley O Elmore
- Department of Pharmaceutical Sciences, University of New Mexico College of Pharmacy, Albuquerque, NM 87131; and
| | - Kathleen D Triplett
- Department of Pharmaceutical Sciences, University of New Mexico College of Pharmacy, Albuquerque, NM 87131; and
| | - Moriah J Castleman
- Department of Pharmaceutical Sciences, University of New Mexico College of Pharmacy, Albuquerque, NM 87131; and
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Pamela R Hall
- Department of Pharmaceutical Sciences, University of New Mexico College of Pharmacy, Albuquerque, NM 87131; and
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60
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Haapasalo K, van Kessel K, Nissilä E, Metso J, Johansson T, Miettinen S, Varjosalo M, Kirveskari J, Kuusela P, Chroni A, Jauhiainen M, van Strijp J, Jokiranta TS. Complement Factor H Binds to Human Serum Apolipoprotein E and Mediates Complement Regulation on High Density Lipoprotein Particles. J Biol Chem 2015; 290:28977-87. [PMID: 26468283 DOI: 10.1074/jbc.m115.669226] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Indexed: 11/06/2022] Open
Abstract
The alternative pathway of complement is an important part of the innate immunity response against foreign particles invading the human body. To avoid damage to host cells, it needs to be efficiently down-regulated by plasma factor H (FH) as exemplified by various diseases caused by mutations in its domains 19-20 (FH19-20) and 5-7 (FH5-7). These regions are also the main interaction sites for microbial pathogens that bind host FH to evade complement attack. We previously showed that inhibition of FH binding by a recombinant FH5-7 construct impairs survival of FH binding pathogens in human blood. In this study we found that upon exposure to full blood, the addition of FH5-7 reduces survival of, surprisingly, also those microbes that are not able to bind FH. This effect was mediated by inhibition of complement regulation and subsequently enhanced neutrophil phagocytosis by FH5-7. We found that although FH5-7 does not reduce complement regulation in the actual fluid phase of plasma, it reduces regulation on HDL particles in plasma. Using affinity chromatography and mass spectrometry we revealed that FH interacts with serum apolipoprotein E (apoE) via FH5-7 domains. Furthermore, binding of FH5-7 to HDL was dependent on the concentration of apoE on the HDL particles. These findings explain why the addition of FH5-7 to plasma leads to excessive complement activation and phagocytosis of microbes in full anticoagulated blood. In conclusion, our data show how FH interacts with apoE molecules via domains 5-7 and regulates alternative pathway activation on plasma HDL particles.
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Affiliation(s)
- Karita Haapasalo
- From the Department of Bacteriology and Immunology, Haartman Institute, and Research Programs Unit, Immunobiology, University of Helsinki, FIN-00014 Helsinki, Finland, Medical Microbiology, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands,
| | - Kok van Kessel
- Medical Microbiology, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands
| | - Eija Nissilä
- From the Department of Bacteriology and Immunology, Haartman Institute, and Research Programs Unit, Immunobiology, University of Helsinki, FIN-00014 Helsinki, Finland
| | - Jari Metso
- Department of Molecular Medicine, National Institute for Health and Welfare, Biomedicum, FI-00290 Helsinki, Finland
| | - Tiira Johansson
- From the Department of Bacteriology and Immunology, Haartman Institute, and Research Programs Unit, Immunobiology, University of Helsinki, FIN-00014 Helsinki, Finland
| | - Sini Miettinen
- University of Helsinki, Institute of Biotechnology, 00014 Helsinki, Finland
| | - Markku Varjosalo
- University of Helsinki, Institute of Biotechnology, 00014 Helsinki, Finland
| | - Juha Kirveskari
- HUSLAB, Helsinki University Central Hospital Laboratory, 00290 Helsinki, Finland, and
| | - Pentti Kuusela
- HUSLAB, Helsinki University Central Hospital Laboratory, 00290 Helsinki, Finland, and
| | - Angelika Chroni
- Institute of Biosciences and Applications, National Center for Scientific Research "Demokritos," 15310 Athens, Greece
| | - Matti Jauhiainen
- Department of Molecular Medicine, National Institute for Health and Welfare, Biomedicum, FI-00290 Helsinki, Finland
| | - Jos van Strijp
- Medical Microbiology, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands
| | - T Sakari Jokiranta
- From the Department of Bacteriology and Immunology, Haartman Institute, and Research Programs Unit, Immunobiology, University of Helsinki, FIN-00014 Helsinki, Finland
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61
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Berlon NR, Qi R, Sharma-Kuinkel BK, Joo HS, Park LP, George D, Thaden JT, Messina JA, Maskarinec SA, Mueller-Premru M, Athan E, Tattevin P, Pericas JM, Woods CW, Otto M, Fowler VG. Clinical MRSA isolates from skin and soft tissue infections show increased in vitro production of phenol soluble modulins. J Infect 2015; 71:447-57. [PMID: 26079275 PMCID: PMC4816458 DOI: 10.1016/j.jinf.2015.06.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Revised: 06/05/2015] [Accepted: 06/08/2015] [Indexed: 10/23/2022]
Abstract
BACKGROUND Phenol-soluble modulins (PSMs) are amphipathic, pro-inflammatory proteins secreted by most Staphylococcus aureus isolates. This study tested the hypothesis that in vitro PSM production levels are associated with specific clinical phenotypes. METHODS 177 methicillin-resistant S. aureus (MRSA) isolates from infective endocarditis (IE), skin and soft tissue infection (SSTI), and hospital-acquired/ventilator-associated pneumonia (HAP) were matched by geographic origin, then genotyped using spa-typing. In vitro PSM production was measured by high performance liquid chromatography/mass spectrometry. Statistical analysis was performed using Chi-squared or Kruskal-Wallis tests as appropriate. RESULTS Spa type 1 was significantly more common in SSTI isolates (62.7% SSTI; 1.7% IE; 16.9% HAP; p < 0.0001) while HAP and IE isolates were more commonly spa type 2 (0% SSTI; 37.3% IE; 40.7% HAP; p < 0.0001). USA300 isolates produced the highest levels of PSMs in vitro. SSTI isolates produced significantly higher quantities of PSMα1-4, PSMβ1, and δ-toxin than other isolates (p < 0.001). These findings persisted when USA300 isolates were excluded from analysis. CONCLUSIONS Increased in vitro production of PSMs is associated with an SSTI clinical source. This significant association persisted after exclusion of USA300 genotype isolates from analysis, suggesting that PSMs play a particularly important role in the pathogenesis of SSTI as compared to other infection types.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Eugene Athan
- Barwon Health, Deakin University, VIC, Australia
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62
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Mairpady Shambat S, Chen P, Nguyen Hoang AT, Bergsten H, Vandenesch F, Siemens N, Lina G, Monk IR, Foster TJ, Arakere G, Svensson M, Norrby-Teglund A. Modelling staphylococcal pneumonia in a human 3D lung tissue model system delineates toxin-mediated pathology. Dis Model Mech 2015; 8:1413-25. [PMID: 26398950 PMCID: PMC4631791 DOI: 10.1242/dmm.021923] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 08/27/2015] [Indexed: 12/17/2022] Open
Abstract
Staphylococcus aureus necrotizing pneumonia is recognized as a toxin-mediated disease, yet the tissue-destructive events remain elusive, partly as a result of lack of mechanistic studies in human lung tissue. In this study, a three-dimensional (3D) tissue model composed of human lung epithelial cells and fibroblasts was used to delineate the role of specific staphylococcal exotoxins in tissue pathology associated with severe pneumonia. To this end, the models were exposed to the mixture of exotoxins produced by S. aureus strains isolated from patients with varying severity of lung infection, namely necrotizing pneumonia or lung empyema, or to purified toxins. The necrotizing pneumonia strains secreted high levels of α-toxin and Panton-Valentine leukocidin (PVL), and triggered high cytotoxicity, inflammation, necrosis and loss of E-cadherin from the lung epithelium. In contrast, the lung empyema strain produced moderate levels of PVL, but negligible amounts of α-toxin, and triggered limited tissue damage. α-toxin had a direct damaging effect on the epithelium, as verified using toxin-deficient mutants and pure α-toxin. Moreover, PVL contributed to pathology through the lysis of neutrophils. A combination of α-toxin and PVL resulted in the most severe epithelial injury. In addition, toxin-induced release of pro-inflammatory mediators from lung tissue models resulted in enhanced neutrophil migration. Using a collection of 31 strains from patients with staphylococcal pneumonia revealed that strains producing high levels of α-toxin and PVL were cytotoxic and associated with fatal outcome. Also, the strains that produced the highest toxin levels induced significantly greater epithelial disruption. Of importance, toxin-mediated lung epithelium destruction could be inhibited by polyspecific intravenous immunoglobulin containing antibodies against α-toxin and PVL. This study introduces a novel model system for study of staphylococcal pneumonia in a human setting. The results reveal that the combination and levels of α-toxin and PVL correlate with tissue pathology and clinical outcome associated with pneumonia.
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Affiliation(s)
- Srikanth Mairpady Shambat
- Department of Medicine Huddinge, Karolinska Institutet, Centre for Infectious Medicine, S-141 86 Stockholm, Sweden
| | - Puran Chen
- Department of Medicine Huddinge, Karolinska Institutet, Centre for Infectious Medicine, S-141 86 Stockholm, Sweden
| | - Anh Thu Nguyen Hoang
- Department of Medicine Huddinge, Karolinska Institutet, Centre for Infectious Medicine, S-141 86 Stockholm, Sweden
| | - Helena Bergsten
- Department of Medicine Huddinge, Karolinska Institutet, Centre for Infectious Medicine, S-141 86 Stockholm, Sweden
| | - Francois Vandenesch
- CIRI, International Center for Infectiology Research, Inserm, U1111, CNRS UMR5308, Université Lyon 1, École Normale Supérieure de Lyon, 69008 Lyon, France French National Reference Center for Staphylococci, Hospices Civils de Lyon, 69677 Bron Cedex, France
| | - Nikolai Siemens
- Department of Medicine Huddinge, Karolinska Institutet, Centre for Infectious Medicine, S-141 86 Stockholm, Sweden
| | - Gerard Lina
- CIRI, International Center for Infectiology Research, Inserm, U1111, CNRS UMR5308, Université Lyon 1, École Normale Supérieure de Lyon, 69008 Lyon, France French National Reference Center for Staphylococci, Hospices Civils de Lyon, 69677 Bron Cedex, France
| | - Ian R Monk
- Department of Microbiology, Moyne Institute of Preventive Medicine, Trinity College, Dublin 2, Ireland
| | - Timothy J Foster
- Department of Microbiology, Moyne Institute of Preventive Medicine, Trinity College, Dublin 2, Ireland
| | - Gayathri Arakere
- Society for Innovation and Development, Indian Institute of Science Campus, Bangalore 560012, India
| | - Mattias Svensson
- Department of Medicine Huddinge, Karolinska Institutet, Centre for Infectious Medicine, S-141 86 Stockholm, Sweden
| | - Anna Norrby-Teglund
- Department of Medicine Huddinge, Karolinska Institutet, Centre for Infectious Medicine, S-141 86 Stockholm, Sweden
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63
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Laabei M, Uhlemann AC, Lowy FD, Austin ED, Yokoyama M, Ouadi K, Feil E, Thorpe HA, Williams B, Perkins M, Peacock SJ, Clarke SR, Dordel J, Holden M, Votintseva AA, Bowden R, Crook DW, Young BC, Wilson DJ, Recker M, Massey RC. Evolutionary Trade-Offs Underlie the Multi-faceted Virulence of Staphylococcus aureus. PLoS Biol 2015; 13:e1002229. [PMID: 26331877 PMCID: PMC4558032 DOI: 10.1371/journal.pbio.1002229] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 07/20/2015] [Indexed: 12/15/2022] Open
Abstract
Bacterial virulence is a multifaceted trait where the interactions between pathogen and host factors affect the severity and outcome of the infection. Toxin secretion is central to the biology of many bacterial pathogens and is widely accepted as playing a crucial role in disease pathology. To understand the relationship between toxicity and bacterial virulence in greater depth, we studied two sequenced collections of the major human pathogen Staphylococcus aureus and found an unexpected inverse correlation between bacterial toxicity and disease severity. By applying a functional genomics approach, we identified several novel toxicity-affecting loci responsible for the wide range in toxic phenotypes observed within these collections. To understand the apparent higher propensity of low toxicity isolates to cause bacteraemia, we performed several functional assays, and our findings suggest that within-host fitness differences between high- and low-toxicity isolates in human serum is a contributing factor. As invasive infections, such as bacteraemia, limit the opportunities for onward transmission, highly toxic strains could gain an additional between-host fitness advantage, potentially contributing to the maintenance of toxicity at the population level. Our results clearly demonstrate how evolutionary trade-offs between toxicity, relative fitness, and transmissibility are critical for understanding the multifaceted nature of bacterial virulence. This study shows that, contrary to expectation, toxin secretion inversely correlates with disease severity for the major human pathogen Staphylococcus aureus. Global efforts to counter the growing problem of antibiotic resistance and develop alternative treatment strategies rely on a fuller understanding of when and why opportunistic pathogens cause disease. Recent advances in DNA sequencing technologies have opened up new opportunities to study infectious organisms, yet identifying the genetic variants that explain differences in disease remains challenging. Here we aimed to understand the complex relationship between toxicity—a known risk factor for disease in many bacteria—and infection severity for the major human pathogen S. aureus. Against expectations, we found that the bacteria that caused the most severe disease were the least toxic strains. We were able to determine the mutations responsible for the differences in toxicity and identified a number of novel toxicity-affecting genes. We further discovered that bacterial fitness in human serum could explain the unexpected association of low-toxicity isolates with severe, invasive disease. Invasive S. aureus infections are usually considered a dead end for these bacteria, as these infections are rarely transmitted to another person. Here we show using a simple mathematical model that this might in fact favour transmission of highly toxic bacteria on a population level and thus contribute to their global success. Our work therefore highlights the complexity of bacterial infection and should aid in devising new treatment and control strategies against this important pathogen.
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Affiliation(s)
- Maisem Laabei
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Anne-Catrin Uhlemann
- Department of Medicine, Columbia University, New York, New York, United States of America
| | - Franklin D. Lowy
- Department of Medicine, Columbia University, New York, New York, United States of America
| | - Eloise D. Austin
- Department of Medicine, Columbia University, New York, New York, United States of America
| | - Maho Yokoyama
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Khadija Ouadi
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Edward Feil
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Harry A. Thorpe
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Barnabas Williams
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Mark Perkins
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Sharon J. Peacock
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Stephen R. Clarke
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, United Kingdom
| | - Janina Dordel
- Pathogen Genomics, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Matthew Holden
- Pathogen Genomics, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom
- School of Medicine, Medical & Biological Sciences, North Haugh, St Andrews, Fife, United Kingdom
| | - Antonina A. Votintseva
- Nuffield Dept. of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom
| | - Rory Bowden
- Wellcome Trust Centre for Human Genetics, Oxford, United Kingdom
| | - Derrick W. Crook
- Nuffield Dept. of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom
| | - Bernadette C. Young
- Nuffield Dept. of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom
| | - Daniel J. Wilson
- Nuffield Dept. of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom
- Wellcome Trust Centre for Human Genetics, Oxford, United Kingdom
| | - Mario Recker
- Centre for Mathematics and the Environment, University of Exeter, Penryn Campus, Penryn, United Kingdom
| | - Ruth C. Massey
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
- * E-mail:
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64
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Spaan AN, Reyes-Robles T, Badiou C, Cochet S, Boguslawski KM, Yoong P, Day CJ, de Haas CJC, van Kessel KPM, Vandenesch F, Jennings MP, Le Van Kim C, Colin Y, van Strijp JAG, Henry T, Torres VJ. Staphylococcus aureus Targets the Duffy Antigen Receptor for Chemokines (DARC) to Lyse Erythrocytes. Cell Host Microbe 2015; 18:363-70. [PMID: 26320997 DOI: 10.1016/j.chom.2015.08.001] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Revised: 07/02/2015] [Accepted: 08/03/2015] [Indexed: 12/30/2022]
Abstract
In order for Staphylococcus aureus to thrive inside the mammalian host, the bacterium has to overcome iron scarcity. S. aureus is thought to produce toxins that lyse erythrocytes, releasing hemoglobin, the most abundant iron source in mammals. Here we identify the Duffy antigen receptor for chemokines (DARC) as the receptor for the S. aureus hemolytic leukocidins LukED and HlgAB. By assessing human erythrocytes with DARC polymorphisms, we determined that HlgAB- and LukED-mediated lysis directly relates to DARC expression. DARC is required for S. aureus-mediated lysis of human erythrocytes, and DARC overexpression is sufficient to render cells susceptible to toxin-mediated lysis. HlgA and LukE bind directly to DARC through different regions, and by targeting DARC, HlgAB and LukED support S. aureus growth in a hemoglobin-acquisition-dependent manner. These findings elucidate how S. aureus targets and lyses erythrocytes to release one of the scarcest nutrients within the mammalian host.
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Affiliation(s)
- András N Spaan
- CIRI, Inserm U1111, CNRS UMR 5308, Lyon, France; Université Claude Bernard Lyon-1, Ecole Normale Supérieure, 69007 Lyon, France; Department of Medical Microbiology, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
| | - Tamara Reyes-Robles
- Department of Microbiology, New York University School of Medicine, NY 10016, USA
| | - Cédric Badiou
- CIRI, Inserm U1111, CNRS UMR 5308, Lyon, France; Université Claude Bernard Lyon-1, Ecole Normale Supérieure, 69007 Lyon, France
| | - Sylvie Cochet
- Inserm U1134, Paris, France; Université Paris Diderot, Sorbonne Paris Cité, UMR_S1134, Paris, France; Institut National de la Transfusion Sanguine, F-75739 Paris, France; Laboratoire d'Excellence GR-Ex, 75238 Paris, France
| | | | - Pauline Yoong
- Department of Microbiology, New York University School of Medicine, NY 10016, USA
| | - Christopher J Day
- Institute for Glycomics, Griffith University, Gold Coast, Queensland 4222, Australia
| | - Carla J C de Haas
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
| | - Kok P M van Kessel
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
| | - François Vandenesch
- CIRI, Inserm U1111, CNRS UMR 5308, Lyon, France; Université Claude Bernard Lyon-1, Ecole Normale Supérieure, 69007 Lyon, France; Hospices Civils de Lyon, 69007 Lyon, France
| | - Michael P Jennings
- Institute for Glycomics, Griffith University, Gold Coast, Queensland 4222, Australia
| | - Caroline Le Van Kim
- Inserm U1134, Paris, France; Université Paris Diderot, Sorbonne Paris Cité, UMR_S1134, Paris, France; Institut National de la Transfusion Sanguine, F-75739 Paris, France; Laboratoire d'Excellence GR-Ex, 75238 Paris, France
| | - Yves Colin
- Inserm U1134, Paris, France; Université Paris Diderot, Sorbonne Paris Cité, UMR_S1134, Paris, France; Institut National de la Transfusion Sanguine, F-75739 Paris, France; Laboratoire d'Excellence GR-Ex, 75238 Paris, France
| | - Jos A G van Strijp
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
| | - Thomas Henry
- CIRI, Inserm U1111, CNRS UMR 5308, Lyon, France; Université Claude Bernard Lyon-1, Ecole Normale Supérieure, 69007 Lyon, France.
| | - Victor J Torres
- Department of Microbiology, New York University School of Medicine, NY 10016, USA.
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65
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Staphlyococcus aureus phenol-soluble modulins stimulate the release of proinflammatory cytokines from keratinocytes and are required for induction of skin inflammation. Infect Immun 2015; 83:3428-37. [PMID: 26077761 DOI: 10.1128/iai.00401-15] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 06/10/2015] [Indexed: 12/22/2022] Open
Abstract
Staphylococcus aureus is a human commensal that colonizes the skin. While it is normally innocuous, it has strong associations with atopic dermatitis pathogenesis and has become the leading cause of skin and soft tissue infections in the United States. The factors that dictate the role of S. aureus in disease are still being determined. In this work, we utilized primary keratinocyte culture and an epidermal murine colonization model to investigate the role of S. aureus phenol-soluble modulins (PSMs) in proinflammatory cytokine release and inflammation induction. We demonstrated that many species of Staphylococcus are capable of causing release of interleukin 18 (IL-18) from keratinocytes and that S. aureus PSMs are necessary and sufficient to stimulate IL-18 release from keratinocytes independently of caspase 1. Further, after 7 days of epicutaneous exposure to wild-type S. aureus, but not S. aureus Δpsm, we saw dramatic changes in gross pathology, as well as systemic release of proinflammatory cytokines. This work demonstrates the importance of PSM peptides in S. aureus-mediated inflammatory cytokine release from keratinocytes in vitro and in vivo and further implicates PSMs as important contributors to pathogenesis.
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66
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Bovine Staphylococcus aureus Secretes the Leukocidin LukMF' To Kill Migrating Neutrophils through CCR1. mBio 2015; 6:e00335. [PMID: 26045537 PMCID: PMC4462618 DOI: 10.1128/mbio.00335-15] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Although Staphylococcus aureus is best known for infecting humans, bovine-specific strains are a major cause of mastitis in dairy cattle. The bicomponent leukocidin LukMF′, exclusively harbored by S. aureus of ruminant origin, is a virulence factor associated with bovine infections. In this study, the molecular basis of the host specificity of LukMF′ is elucidated by identification of chemokine receptor CCR1 as its target. Bovine neutrophils, the major effector cells in the defense against staphylococci, express significant cell surface levels of CCR1, whereas human neutrophils do not. This causes the particular susceptibility of bovine neutrophils to pore formation induced by LukMF′. Bovine S. aureus strains produce high levels of LukMF′ in vitro. In culture supernatant of the mastitis field isolate S1444, LukMF′ was the most important cytotoxic agent for bovine neutrophils. In a fibrin gel matrix, the effects of the in situ secreted toxins on neutrophils migrating toward S. aureus were visualized. Under these physiological ex vivo conditions, bovine S. aureus S1444 efficiently killed approaching neutrophils at a distance through secretion of LukMF′. Altogether, our findings illustrate the coevolution of pathogen and host, provide new targets for therapeutic and vaccine approaches to treat staphylococcal diseases in the cow, and emphasize the importance of staphylococcal toxins in general. This study explains the mechanism of action of LukMF′, a bicomponent toxin found in bovine lineages of S. aureus that is associated with mastitis in cattle. At a molecular level, we describe how LukMF′ can specifically kill bovine neutrophils. Here, we demonstrate the contribution of toxins in the determination of host specificity and contribute to the understanding of mechanisms of coevolution of pathogen and host. Our study provides new targets that can be used in therapeutic and vaccine approaches to treat staphylococcal diseases in the cow. We also demonstrate the importance of toxins in specific elimination of immune cells, which has broader implications, especially in human infections.
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67
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Elmore BO, Triplett KD, Hall PR. Apolipoprotein B48, the Structural Component of Chylomicrons, Is Sufficient to Antagonize Staphylococcus aureus Quorum-Sensing. PLoS One 2015; 10:e0125027. [PMID: 25942561 PMCID: PMC4420250 DOI: 10.1371/journal.pone.0125027] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 03/19/2015] [Indexed: 01/09/2023] Open
Abstract
Serum lipoproteins (LP) are increasingly being recognized as dual purpose molecules that contribute to both cholesterol homeostasis and host innate defense. In fact, very low LP levels are associated with increased risk of bacterial infection in critically ill patients. In this respect, we reported that apolipoprotein B100 (apoB100), the 4536 amino acid structural protein of very low density lipoprotein (VLDL) produced by the liver, limits Staphylococcus aureus pathogenesis. S. aureus uses quorum-sensing (QS) via the accessory gene regulator (agr) operon and an autoinducing peptide (AIP) to coordinate expression of over 200 virulence genes. ApoB100 prevents agr activation by binding and sequestering secreted AIP. Importantly, human serum LP are produced not only by the liver, but are also produced by enterocytes, in the form of chylomicrons, during uptake of dietary lipids. In contrast to apoB100 in VLDL, human enterocytes use apoB48, the N-terminal 2152 amino acids (48%) of apoB100, as the structural component of chylomicrons. Interestingly, enteral feeding of critically ill patients has been associated with decreased risk of infectious complications, suggesting chylomicrons could contribute to host innate defense in critically ill patients when serum LP production by the liver is limited during the acute phase response. Therefore, we hypothesized that apoB48 would be sufficient to antagonize S. aureus QS. As expected, isolated apoB48-LP bound immobilized AIP and antagonized agr-signaling. ApoB48- and apoB100-LP inhibited agr activation with IC50s of 3.5 and 2.3 nM, respectively, demonstrating a conserved AIP binding site. Importantly, apoB48-LP antagonized QS, limited morbidity and promoted bacterial clearance in a mouse model of S. aureus infection. This work demonstrates that both naturally occurring forms of apolipoprotein B can antagonize S. aureus QS, and may suggest a previously unrecognized role for chylomicrons and enterocytes in host innate defense against S. aureus QS-mediated pathogenesis.
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Affiliation(s)
- Bradley O. Elmore
- Department of Pharmaceutical Sciences, University of New Mexico College of Pharmacy, Albuquerque, New Mexico, United States of America
| | - Kathleen D. Triplett
- Department of Pharmaceutical Sciences, University of New Mexico College of Pharmacy, Albuquerque, New Mexico, United States of America
| | - Pamela R. Hall
- Department of Pharmaceutical Sciences, University of New Mexico College of Pharmacy, Albuquerque, New Mexico, United States of America
- * E-mail:
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68
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Deplanche M, Filho RAEA, Alekseeva L, Ladier E, Jardin J, Henry G, Azevedo V, Miyoshi A, Beraud L, Laurent F, Lina G, Vandenesch F, Steghens JP, Le Loir Y, Otto M, Götz F, Berkova N. Phenol-soluble modulin α induces G2/M phase transition delay in eukaryotic HeLa cells. FASEB J 2015; 29:1950-9. [PMID: 25648996 DOI: 10.1096/fj.14-260513] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 01/02/2015] [Indexed: 12/20/2022]
Abstract
Staphylococcus aureus is a gram-positive bacterium responsible for a wide range of infections. Host cell cycle alteration is a sophisticated mechanism used by pathogens to hijack the defense functions of host cells. We previously demonstrated that S. aureus MW2 (USA400) bacteria induced a G2/M phase transition delay in HeLa cells. We demonstrate here that this activity is triggered by culture supernatant compounds. Using size exclusion chromatography of the MW2 supernatant, followed by mass spectroscopy analysis of corresponding peaks, we identified phenol-soluble modulin α (PSMα) peptides as the likely candidates for this effect. Indeed, synthetic PSMα1 and PSMα3 caused a G2/M phase transition delay. The implication of PSMα in cell cycle alteration was confirmed by comparison of S. aureus Los Angeles County clone (LAC) wild-type with the isogenic mutant LAC∆psmα, which lacks the psmα operon encoding PSMα1-4. PSMα-induced G2/M transition delay correlated with a decrease in the defensin genes expression suggesting a diminution of antibacterial functions of epithelial cells. By testing the supernatant of S. aureus human clinical isolates, we found that the degree of G2/M phase transition delay correlated with PSMα1 production. We show that PSMs secreted by S. aureus alter the host cell cycle, revealing a newly identified mechanism for fostering an infection.
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Affiliation(s)
- Martine Deplanche
- *Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1253 STLO, Rennes, France; Agrocampus Ouest, Unité Mixtes de Recherche1253 STLO, Rennes, France; Instituto de Ciências Biológicas- Universidade Federal de Minas Gerais , Belo Horizonte- Minas Gerais, Brazil; Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russia; Centre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale U1111, Centre National de la Recherche Scientifique Unité Mixtes de Recherche5308, Université Lyon 1, Lyon, France; Hospices Civil de Lyon, Lyon, France; Laboratory of Human Bacterial Pathogenesis, National Institutes of Health, Bethesda, Maryland, USA; and **Microbial Genetics, University of Tübingen, Tübingen, Germany
| | - Rachid Aref El-Aouar Filho
- *Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1253 STLO, Rennes, France; Agrocampus Ouest, Unité Mixtes de Recherche1253 STLO, Rennes, France; Instituto de Ciências Biológicas- Universidade Federal de Minas Gerais , Belo Horizonte- Minas Gerais, Brazil; Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russia; Centre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale U1111, Centre National de la Recherche Scientifique Unité Mixtes de Recherche5308, Université Lyon 1, Lyon, France; Hospices Civil de Lyon, Lyon, France; Laboratory of Human Bacterial Pathogenesis, National Institutes of Health, Bethesda, Maryland, USA; and **Microbial Genetics, University of Tübingen, Tübingen, Germany
| | - Ludmila Alekseeva
- *Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1253 STLO, Rennes, France; Agrocampus Ouest, Unité Mixtes de Recherche1253 STLO, Rennes, France; Instituto de Ciências Biológicas- Universidade Federal de Minas Gerais , Belo Horizonte- Minas Gerais, Brazil; Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russia; Centre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale U1111, Centre National de la Recherche Scientifique Unité Mixtes de Recherche5308, Université Lyon 1, Lyon, France; Hospices Civil de Lyon, Lyon, France; Laboratory of Human Bacterial Pathogenesis, National Institutes of Health, Bethesda, Maryland, USA; and **Microbial Genetics, University of Tübingen, Tübingen, Germany
| | - Emilie Ladier
- *Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1253 STLO, Rennes, France; Agrocampus Ouest, Unité Mixtes de Recherche1253 STLO, Rennes, France; Instituto de Ciências Biológicas- Universidade Federal de Minas Gerais , Belo Horizonte- Minas Gerais, Brazil; Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russia; Centre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale U1111, Centre National de la Recherche Scientifique Unité Mixtes de Recherche5308, Université Lyon 1, Lyon, France; Hospices Civil de Lyon, Lyon, France; Laboratory of Human Bacterial Pathogenesis, National Institutes of Health, Bethesda, Maryland, USA; and **Microbial Genetics, University of Tübingen, Tübingen, Germany
| | - Julien Jardin
- *Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1253 STLO, Rennes, France; Agrocampus Ouest, Unité Mixtes de Recherche1253 STLO, Rennes, France; Instituto de Ciências Biológicas- Universidade Federal de Minas Gerais , Belo Horizonte- Minas Gerais, Brazil; Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russia; Centre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale U1111, Centre National de la Recherche Scientifique Unité Mixtes de Recherche5308, Université Lyon 1, Lyon, France; Hospices Civil de Lyon, Lyon, France; Laboratory of Human Bacterial Pathogenesis, National Institutes of Health, Bethesda, Maryland, USA; and **Microbial Genetics, University of Tübingen, Tübingen, Germany
| | - Gwénaële Henry
- *Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1253 STLO, Rennes, France; Agrocampus Ouest, Unité Mixtes de Recherche1253 STLO, Rennes, France; Instituto de Ciências Biológicas- Universidade Federal de Minas Gerais , Belo Horizonte- Minas Gerais, Brazil; Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russia; Centre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale U1111, Centre National de la Recherche Scientifique Unité Mixtes de Recherche5308, Université Lyon 1, Lyon, France; Hospices Civil de Lyon, Lyon, France; Laboratory of Human Bacterial Pathogenesis, National Institutes of Health, Bethesda, Maryland, USA; and **Microbial Genetics, University of Tübingen, Tübingen, Germany
| | - Vasco Azevedo
- *Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1253 STLO, Rennes, France; Agrocampus Ouest, Unité Mixtes de Recherche1253 STLO, Rennes, France; Instituto de Ciências Biológicas- Universidade Federal de Minas Gerais , Belo Horizonte- Minas Gerais, Brazil; Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russia; Centre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale U1111, Centre National de la Recherche Scientifique Unité Mixtes de Recherche5308, Université Lyon 1, Lyon, France; Hospices Civil de Lyon, Lyon, France; Laboratory of Human Bacterial Pathogenesis, National Institutes of Health, Bethesda, Maryland, USA; and **Microbial Genetics, University of Tübingen, Tübingen, Germany
| | - Anderson Miyoshi
- *Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1253 STLO, Rennes, France; Agrocampus Ouest, Unité Mixtes de Recherche1253 STLO, Rennes, France; Instituto de Ciências Biológicas- Universidade Federal de Minas Gerais , Belo Horizonte- Minas Gerais, Brazil; Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russia; Centre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale U1111, Centre National de la Recherche Scientifique Unité Mixtes de Recherche5308, Université Lyon 1, Lyon, France; Hospices Civil de Lyon, Lyon, France; Laboratory of Human Bacterial Pathogenesis, National Institutes of Health, Bethesda, Maryland, USA; and **Microbial Genetics, University of Tübingen, Tübingen, Germany
| | - Laetitia Beraud
- *Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1253 STLO, Rennes, France; Agrocampus Ouest, Unité Mixtes de Recherche1253 STLO, Rennes, France; Instituto de Ciências Biológicas- Universidade Federal de Minas Gerais , Belo Horizonte- Minas Gerais, Brazil; Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russia; Centre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale U1111, Centre National de la Recherche Scientifique Unité Mixtes de Recherche5308, Université Lyon 1, Lyon, France; Hospices Civil de Lyon, Lyon, France; Laboratory of Human Bacterial Pathogenesis, National Institutes of Health, Bethesda, Maryland, USA; and **Microbial Genetics, University of Tübingen, Tübingen, Germany
| | - Frederic Laurent
- *Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1253 STLO, Rennes, France; Agrocampus Ouest, Unité Mixtes de Recherche1253 STLO, Rennes, France; Instituto de Ciências Biológicas- Universidade Federal de Minas Gerais , Belo Horizonte- Minas Gerais, Brazil; Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russia; Centre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale U1111, Centre National de la Recherche Scientifique Unité Mixtes de Recherche5308, Université Lyon 1, Lyon, France; Hospices Civil de Lyon, Lyon, France; Laboratory of Human Bacterial Pathogenesis, National Institutes of Health, Bethesda, Maryland, USA; and **Microbial Genetics, University of Tübingen, Tübingen, Germany
| | - Gerard Lina
- *Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1253 STLO, Rennes, France; Agrocampus Ouest, Unité Mixtes de Recherche1253 STLO, Rennes, France; Instituto de Ciências Biológicas- Universidade Federal de Minas Gerais , Belo Horizonte- Minas Gerais, Brazil; Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russia; Centre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale U1111, Centre National de la Recherche Scientifique Unité Mixtes de Recherche5308, Université Lyon 1, Lyon, France; Hospices Civil de Lyon, Lyon, France; Laboratory of Human Bacterial Pathogenesis, National Institutes of Health, Bethesda, Maryland, USA; and **Microbial Genetics, University of Tübingen, Tübingen, Germany
| | - François Vandenesch
- *Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1253 STLO, Rennes, France; Agrocampus Ouest, Unité Mixtes de Recherche1253 STLO, Rennes, France; Instituto de Ciências Biológicas- Universidade Federal de Minas Gerais , Belo Horizonte- Minas Gerais, Brazil; Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russia; Centre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale U1111, Centre National de la Recherche Scientifique Unité Mixtes de Recherche5308, Université Lyon 1, Lyon, France; Hospices Civil de Lyon, Lyon, France; Laboratory of Human Bacterial Pathogenesis, National Institutes of Health, Bethesda, Maryland, USA; and **Microbial Genetics, University of Tübingen, Tübingen, Germany
| | - Jean-Paul Steghens
- *Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1253 STLO, Rennes, France; Agrocampus Ouest, Unité Mixtes de Recherche1253 STLO, Rennes, France; Instituto de Ciências Biológicas- Universidade Federal de Minas Gerais , Belo Horizonte- Minas Gerais, Brazil; Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russia; Centre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale U1111, Centre National de la Recherche Scientifique Unité Mixtes de Recherche5308, Université Lyon 1, Lyon, France; Hospices Civil de Lyon, Lyon, France; Laboratory of Human Bacterial Pathogenesis, National Institutes of Health, Bethesda, Maryland, USA; and **Microbial Genetics, University of Tübingen, Tübingen, Germany
| | - Yves Le Loir
- *Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1253 STLO, Rennes, France; Agrocampus Ouest, Unité Mixtes de Recherche1253 STLO, Rennes, France; Instituto de Ciências Biológicas- Universidade Federal de Minas Gerais , Belo Horizonte- Minas Gerais, Brazil; Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russia; Centre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale U1111, Centre National de la Recherche Scientifique Unité Mixtes de Recherche5308, Université Lyon 1, Lyon, France; Hospices Civil de Lyon, Lyon, France; Laboratory of Human Bacterial Pathogenesis, National Institutes of Health, Bethesda, Maryland, USA; and **Microbial Genetics, University of Tübingen, Tübingen, Germany
| | - Michael Otto
- *Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1253 STLO, Rennes, France; Agrocampus Ouest, Unité Mixtes de Recherche1253 STLO, Rennes, France; Instituto de Ciências Biológicas- Universidade Federal de Minas Gerais , Belo Horizonte- Minas Gerais, Brazil; Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russia; Centre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale U1111, Centre National de la Recherche Scientifique Unité Mixtes de Recherche5308, Université Lyon 1, Lyon, France; Hospices Civil de Lyon, Lyon, France; Laboratory of Human Bacterial Pathogenesis, National Institutes of Health, Bethesda, Maryland, USA; and **Microbial Genetics, University of Tübingen, Tübingen, Germany
| | - Friedrich Götz
- *Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1253 STLO, Rennes, France; Agrocampus Ouest, Unité Mixtes de Recherche1253 STLO, Rennes, France; Instituto de Ciências Biológicas- Universidade Federal de Minas Gerais , Belo Horizonte- Minas Gerais, Brazil; Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russia; Centre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale U1111, Centre National de la Recherche Scientifique Unité Mixtes de Recherche5308, Université Lyon 1, Lyon, France; Hospices Civil de Lyon, Lyon, France; Laboratory of Human Bacterial Pathogenesis, National Institutes of Health, Bethesda, Maryland, USA; and **Microbial Genetics, University of Tübingen, Tübingen, Germany
| | - Nadia Berkova
- *Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1253 STLO, Rennes, France; Agrocampus Ouest, Unité Mixtes de Recherche1253 STLO, Rennes, France; Instituto de Ciências Biológicas- Universidade Federal de Minas Gerais , Belo Horizonte- Minas Gerais, Brazil; Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russia; Centre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale U1111, Centre National de la Recherche Scientifique Unité Mixtes de Recherche5308, Université Lyon 1, Lyon, France; Hospices Civil de Lyon, Lyon, France; Laboratory of Human Bacterial Pathogenesis, National Institutes of Health, Bethesda, Maryland, USA; and **Microbial Genetics, University of Tübingen, Tübingen, Germany
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Koymans KJ, Vrieling M, Gorham RD, van Strijp JAG. Staphylococcal Immune Evasion Proteins: Structure, Function, and Host Adaptation. Curr Top Microbiol Immunol 2015; 409:441-489. [PMID: 26919864 DOI: 10.1007/82_2015_5017] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Staphylococcus aureus is a successful human and animal pathogen. Its pathogenicity is linked to its ability to secrete a large amount of virulence factors. These secreted proteins interfere with many critical components of the immune system, both innate and adaptive, and hamper proper immune functioning. In recent years, numerous studies have been conducted in order to understand the molecular mechanism underlying the interaction of evasion molecules with the host immune system. Structural studies have fundamentally contributed to our understanding of the mechanisms of action of the individual factors. Furthermore, such studies revealed one of the most striking characteristics of the secreted immune evasion molecules: their conserved structure. Despite high-sequence variability, most immune evasion molecules belong to a small number of structural categories. Another remarkable characteristic is that S. aureus carries most of these virulence factors on mobile genetic elements (MGE) or ex-MGE in its accessory genome. Coevolution of pathogen and host has resulted in immune evasion molecules with a highly host-specific function and prevalence. In this review, we explore how these shared structures and genomic locations relate to function and host specificity. This is discussed in the context of therapeutic options for these immune evasion molecules in infectious as well as in inflammatory diseases.
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Affiliation(s)
- Kirsten J Koymans
- Department of Medical Microbiology, University Medical Center Utrecht, G04-614, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands.
| | - Manouk Vrieling
- Department of Medical Microbiology, University Medical Center Utrecht, G04-614, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
| | - Ronald D Gorham
- Department of Medical Microbiology, University Medical Center Utrecht, G04-614, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
| | - Jos A G van Strijp
- Department of Medical Microbiology, University Medical Center Utrecht, G04-614, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
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70
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Bloes DA, Kretschmer D, Peschel A. Enemy attraction: bacterial agonists for leukocyte chemotaxis receptors. Nat Rev Microbiol 2014; 13:95-104. [PMID: 25534805 DOI: 10.1038/nrmicro3390] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The innate immune system recognizes conserved microorganism-associated molecular patterns (MAMPs), some of which are sensed by G protein-coupled receptors (GPCRs), and this leads to chemotactic leukocyte influx. Recent studies have indicated that these processes are crucial for host defence and rely on a larger set of chemotactic MAMPs and corresponding GPCRs than was previously thought. Agonists, such as bacterial formyl peptides, enterococcal pheromone peptides, staphylococcal peptide toxins, bacterial fermentation products and the Helicobacter pylori peptide HP(2-20), stimulate specific GPCRs. The importance of leukocyte chemotaxis in host defence is highlighted by the fact that some bacterial pathogens produce chemotaxis inhibitors. How the various chemoattractants, receptors and antagonists shape antibacterial host defence represents an important topic for future research.
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Affiliation(s)
- Dominik Alexander Bloes
- Cellular and Molecular Microbiology Division, Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Tübingen 72076, Germany
| | - Dorothee Kretschmer
- Cellular and Molecular Microbiology Division, Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Tübingen 72076, Germany
| | - Andreas Peschel
- Cellular and Molecular Microbiology Division, Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Tübingen 72076, Germany
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71
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Spaan AN, Vrieling M, Wallet P, Badiou C, Reyes-Robles T, Ohneck EA, Benito Y, de Haas CJ, Day CJ, Jennings MP, Lina G, Vandenesch F, van Kessel KP, Torres VJ, van Strijp JA, Henry T. The staphylococcal toxins γ-haemolysin AB and CB differentially target phagocytes by employing specific chemokine receptors. Nat Commun 2014; 5:5438. [PMID: 25384670 PMCID: PMC4228697 DOI: 10.1038/ncomms6438] [Citation(s) in RCA: 111] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Accepted: 10/01/2014] [Indexed: 12/20/2022] Open
Abstract
Evasion of the host phagocyte response by Staphylococcus aureus is crucial to successful infection with the pathogen. γ-haemolysin AB and CB (HlgAB, HlgCB) are bicomponent pore-forming toxins present in almost all human S. aureus isolates. Cellular tropism and contribution of the toxins to S. aureus pathophysiology are poorly understood. Here we identify the chemokine receptors CXCR1, CXCR2 and CCR2 as targets for HlgAB, and the complement receptors C5aR and C5L2 as targets for HlgCB. The receptor expression patterns allow the toxins to efficiently and differentially target phagocytic cells. Murine neutrophils are resistant to HlgAB and HlgCB. CCR2 is the sole murine receptor orthologue compatible with γ-haemolysin. In a murine peritonitis model, HlgAB contributes to S. aureus bacteremia in a CCR2-dependent manner. HlgAB-mediated targeting of CCR2(+) cells highlights the involvement of inflammatory macrophages during S. aureus infection. Functional quantification identifies HlgAB and HlgCB as major secreted staphylococcal leukocidins.
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MESH Headings
- Animals
- Bacterial Proteins/physiology
- Bacterial Toxins
- Cells, Cultured
- Disease Models, Animal
- Female
- Hemolysin Proteins/physiology
- Humans
- Macrophages/microbiology
- Macrophages/pathology
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Peritonitis/microbiology
- Peritonitis/pathology
- Peritonitis/physiopathology
- Phagocytes/microbiology
- Phagocytes/pathology
- Receptors, CCR2/deficiency
- Receptors, CCR2/genetics
- Receptors, CCR2/physiology
- Receptors, Chemokine/physiology
- Receptors, Complement/physiology
- Receptors, Interleukin-8A/physiology
- Receptors, Interleukin-8B/physiology
- Staphylococcal Infections/pathology
- Staphylococcal Infections/physiopathology
- Staphylococcus aureus
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Affiliation(s)
- András N. Spaan
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
- CIRI, International Center for Infectiology Research, Université Lyon 1 and Ecole Normale Supérieure de Lyon, 69007 Lyon, France
- Inserm, U1111, 69007 Lyon, France
| | - Manouk Vrieling
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
| | - Pierre Wallet
- CIRI, International Center for Infectiology Research, Université Lyon 1 and Ecole Normale Supérieure de Lyon, 69007 Lyon, France
- Inserm, U1111, 69007 Lyon, France
- CNRS, UMR5308, 69007 Lyon, France
| | - Cédric Badiou
- CIRI, International Center for Infectiology Research, Université Lyon 1 and Ecole Normale Supérieure de Lyon, 69007 Lyon, France
- Inserm, U1111, 69007 Lyon, France
- CNRS, UMR5308, 69007 Lyon, France
| | - Tamara Reyes-Robles
- Department of Microbiology, New York University School of Medicine, 10016 New York, USA
| | - Elizabeth A. Ohneck
- Department of Microbiology, New York University School of Medicine, 10016 New York, USA
| | - Yvonne Benito
- CIRI, International Center for Infectiology Research, Université Lyon 1 and Ecole Normale Supérieure de Lyon, 69007 Lyon, France
- Inserm, U1111, 69007 Lyon, France
- CNRS, UMR5308, 69007 Lyon, France
- Centre National de Référence des Staphylocoques, Hospices Civils de Lyon, 69007 Lyon, France
| | - Carla J.C. de Haas
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
| | - Christopher J. Day
- Institute for Glycomics, Griffith University, Gold Coast, Queensland 4222, Australia
| | - Michael P. Jennings
- Institute for Glycomics, Griffith University, Gold Coast, Queensland 4222, Australia
| | - Gérard Lina
- CIRI, International Center for Infectiology Research, Université Lyon 1 and Ecole Normale Supérieure de Lyon, 69007 Lyon, France
- Inserm, U1111, 69007 Lyon, France
- CNRS, UMR5308, 69007 Lyon, France
- Centre National de Référence des Staphylocoques, Hospices Civils de Lyon, 69007 Lyon, France
| | - François Vandenesch
- CIRI, International Center for Infectiology Research, Université Lyon 1 and Ecole Normale Supérieure de Lyon, 69007 Lyon, France
- Inserm, U1111, 69007 Lyon, France
- CNRS, UMR5308, 69007 Lyon, France
- Centre National de Référence des Staphylocoques, Hospices Civils de Lyon, 69007 Lyon, France
| | - Kok P.M. van Kessel
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
| | - Victor J. Torres
- Department of Microbiology, New York University School of Medicine, 10016 New York, USA
| | - Jos A.G. van Strijp
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
| | - Thomas Henry
- CIRI, International Center for Infectiology Research, Université Lyon 1 and Ecole Normale Supérieure de Lyon, 69007 Lyon, France
- Inserm, U1111, 69007 Lyon, France
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Hepburn L, Prajsnar TK, Klapholz C, Moreno P, Loynes CA, Ogryzko NV, Brown K, Schiebler M, Hegyi K, Antrobus R, Hammond KL, Connolly J, Ochoa B, Bryant C, Otto M, Surewaard B, Seneviratne SL, Grogono DM, Cachat J, Ny T, Kaser A, Török ME, Peacock SJ, Holden M, Blundell T, Wang L, Ligoxygakis P, Minichiello L, Woods CG, Foster SJ, Renshaw SA, Floto RA. Innate immunity. A Spaetzle-like role for nerve growth factor β in vertebrate immunity to Staphylococcus aureus. Science 2014; 346:641-646. [PMID: 25359976 PMCID: PMC4255479 DOI: 10.1126/science.1258705] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Many key components of innate immunity to infection are shared between Drosophila and humans. However, the fly Toll ligand Spaetzle is not thought to have a vertebrate equivalent. We have found that the structurally related cystine-knot protein, nerve growth factor β (NGFβ), plays an unexpected Spaetzle-like role in immunity to Staphylococcus aureus infection in chordates. Deleterious mutations of either human NGFβ or its high-affinity receptor tropomyosin-related kinase receptor A (TRKA) were associated with severe S. aureus infections. NGFβ was released by macrophages in response to S. aureus exoproteins through activation of the NOD-like receptors NLRP3 and NLRP4 and enhanced phagocytosis and superoxide-dependent killing, stimulated proinflammatory cytokine production, and promoted calcium-dependent neutrophil recruitment. TrkA knockdown in zebrafish increased susceptibility to S. aureus infection, confirming an evolutionarily conserved role for NGFβ-TRKA signaling in pathogen-specific host immunity.
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Affiliation(s)
- Lucy Hepburn
- Cambridge Institute for Medical Research, University of Cambridge, UK
- Department of Medicine, University of Cambridge, UK
| | - Tomasz K. Prajsnar
- Krebs Institute, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
- Department of Molecular Biology and Biotechnology, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
- Bateson Centre, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
| | - Catherine Klapholz
- Cambridge Institute for Medical Research, University of Cambridge, UK
- Department of Medicine, University of Cambridge, UK
| | - Pablo Moreno
- Cambridge Institute for Medical Research, University of Cambridge, UK
| | - Catherine A. Loynes
- Bateson Centre, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
- Department of Infection and Immunity, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
| | - Nikolay V. Ogryzko
- Bateson Centre, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
| | - Karen Brown
- Cambridge Institute for Medical Research, University of Cambridge, UK
- Department of Medicine, University of Cambridge, UK
- Cambridge Centre for Lung Infection, Papworth Hospital, Cambridge, UK
| | - Mark Schiebler
- Cambridge Institute for Medical Research, University of Cambridge, UK
- Department of Medicine, University of Cambridge, UK
| | - Krisztina Hegyi
- Cambridge Institute for Medical Research, University of Cambridge, UK
- Department of Medicine, University of Cambridge, UK
| | - Robin Antrobus
- Cambridge Institute for Medical Research, University of Cambridge, UK
| | - Katherine L. Hammond
- Bateson Centre, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
- Department of Infection and Immunity, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
| | - John Connolly
- Krebs Institute, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
- Department of Molecular Biology and Biotechnology, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
| | | | - Clare Bryant
- Department of Veterinary Medicine, University of Cambridge, UK
| | - Michael Otto
- Laboratory of Human Bacterial Pathogenesis NIAID, NIH, Bethesda USA
| | - Bas Surewaard
- Dept of Medical Microbiology, University Medical Centre, Utrecht, Netherlands
| | | | - Dorothy M. Grogono
- Department of Medicine, University of Cambridge, UK
- Cambridge Centre for Lung Infection, Papworth Hospital, Cambridge, UK
| | - Julien Cachat
- Dept. of Pathology and Immunology, Geneva University, Switzerland
| | - Tor Ny
- Dept. of Medical Biochemistry and Biophysics, Umea University, Sweden
| | - Arthur Kaser
- Department of Medicine, University of Cambridge, UK
| | | | - Sharon J. Peacock
- Department of Medicine, University of Cambridge, UK
- Wellcome Trust Sanger Institute, Hinxton, UK
| | | | - Tom Blundell
- Department of Biochemistry, University of Cambridge, UK
| | - Lihui Wang
- Biochemistry Department, Oxford University. UK
| | | | | | - C. Geoff Woods
- Cambridge Institute for Medical Research, University of Cambridge, UK
- Department of Medical Genetics, University of Cambridge, UK
| | - Simon J. Foster
- Krebs Institute, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
- Department of Molecular Biology and Biotechnology, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
| | - Stephen A. Renshaw
- Krebs Institute, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
- Bateson Centre, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
- Department of Infection and Immunity, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
| | - R. Andres Floto
- Cambridge Institute for Medical Research, University of Cambridge, UK
- Department of Medicine, University of Cambridge, UK
- Cambridge Centre for Lung Infection, Papworth Hospital, Cambridge, UK
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Painter KL, Krishna A, Wigneshweraraj S, Edwards AM. What role does the quorum-sensing accessory gene regulator system play during Staphylococcus aureus bacteremia? Trends Microbiol 2014; 22:676-85. [PMID: 25300477 DOI: 10.1016/j.tim.2014.09.002] [Citation(s) in RCA: 112] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Revised: 09/10/2014] [Accepted: 09/12/2014] [Indexed: 11/18/2022]
Abstract
Staphylococcus aureus is a major cause of bacteremia, which frequently results in serious secondary infections such as infective endocarditis, osteomyelitis, and septic arthritis. The ability of S. aureus to cause such a wide range of infections has been ascribed to its huge armoury of different virulence factors, many of which are under the control of the quorum-sensing accessory gene regulator (Agr) system. However, a significant fraction of S. aureus bacteremia cases are caused by agr-defective isolates, calling into question the role of Agr in invasive staphylococcal infections. This review draws on recent work to define the role of Agr during bacteremia and explain why the loss of this major virulence regulator is sometimes a price worth paying for S. aureus.
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Affiliation(s)
- Kimberley L Painter
- Section of Microbiology, MRC Centre for Molecular Bacteriology and Infection, Imperial College, Armstrong Road, London SW7 2AZ, UK
| | - Aishwarya Krishna
- Section of Microbiology, MRC Centre for Molecular Bacteriology and Infection, Imperial College, Armstrong Road, London SW7 2AZ, UK
| | - Sivaramesh Wigneshweraraj
- Section of Microbiology, MRC Centre for Molecular Bacteriology and Infection, Imperial College, Armstrong Road, London SW7 2AZ, UK
| | - Andrew M Edwards
- Section of Microbiology, MRC Centre for Molecular Bacteriology and Infection, Imperial College, Armstrong Road, London SW7 2AZ, UK.
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74
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Laabei M, Jamieson WD, Yang Y, van den Elsen J, Jenkins ATA. Investigating the lytic activity and structural properties of Staphylococcus aureus phenol soluble modulin (PSM) peptide toxins. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1838:3153-61. [PMID: 25194683 DOI: 10.1016/j.bbamem.2014.08.026] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Revised: 08/18/2014] [Accepted: 08/25/2014] [Indexed: 11/25/2022]
Abstract
The ubiquitous bacterial pathogen, Staphylococcus aureus, expresses a large arsenal of virulence factors essential for pathogenesis. The phenol-soluble modulins (PSMs) are a family of cytolytic peptide toxins which have multiple roles in staphylococcal virulence. To gain an insight into which specific factors are important in PSM-mediated cell membrane disruption, the lytic activity of individual PSM peptides against phospholipid vesicles and T cells was investigated. Vesicles were most susceptible to lysis by the PSMα subclass of peptides (α1-3 in particular), when containing between 10 and 30mol% cholesterol, which for these vesicles is the mixed solid ordered (so)-liquid ordered (lo) phase. Our results show that the PSMβ class of peptides has little effect on vesicles at concentrations comparable to that of the PSMα class and exhibited no cytotoxicity. Furthermore, within the PSMα class, differences emerged with PSMα4 showing decreased vesicle and cytotoxic activity in comparison to its counterparts, in contrast to previous studies. In order to understand this, peptides were studied using helical wheel projections and circular dichroism measurements. The degree of amphipathicity, alpha-helicity and properties such as charge and hydrophobicity were calculated, allowing a structure-function relationship to be inferred. The degree of alpha-helicity of the peptides was the single most important property of the seven peptides studied in predicting their lytic activity. These results help to redefine this class of peptide toxins and also highlight certain membrane parameters required for efficient lysis.
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Affiliation(s)
- Maisem Laabei
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK; Department of Biology and Biochemistry, Claverton Down, Bath BA2 7AY, UK
| | - W David Jamieson
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK
| | - Yi Yang
- Department of Biology and Biochemistry, Claverton Down, Bath BA2 7AY, UK
| | - Jean van den Elsen
- Department of Biology and Biochemistry, Claverton Down, Bath BA2 7AY, UK
| | - A Toby A Jenkins
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK.
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75
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Syed AK, Boles BR. Fold modulating function: bacterial toxins to functional amyloids. Front Microbiol 2014; 5:401. [PMID: 25136340 PMCID: PMC4118032 DOI: 10.3389/fmicb.2014.00401] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Accepted: 07/16/2014] [Indexed: 12/11/2022] Open
Abstract
Many bacteria produce cytolytic toxins that target host cells or other competing microbes. It is well known that environmental factors control toxin expression, however, recent work suggests that some bacteria manipulate the fold of these protein toxins to control their function. The β-sheet rich amyloid fold is a highly stable ordered aggregate that many toxins form in response to specific environmental conditions. When in the amyloid state, toxins become inert, losing the cytolytic activity they display in the soluble form. Emerging evidence suggest that some amyloids function as toxin storage systems until they are again needed, while other bacteria utilize amyloids as a structural matrix component of biofilms. This amyloid matrix component facilitates resistance to biofilm disruptive challenges. The bacterial amyloids discussed in this review reveal an elegant system where changes in protein fold and solubility dictate the function of proteins in response to the environment.
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Affiliation(s)
- Adnan K Syed
- Department of Molecular Cellular and Developmental Biology, University of Michigan Ann Arbor, MI, USA
| | - Blaise R Boles
- Department of Microbiology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa Iowa City, IA, USA
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76
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Kim HK, Missiakas D, Schneewind O. Mouse models for infectious diseases caused by Staphylococcus aureus. J Immunol Methods 2014; 410:88-99. [PMID: 24769066 PMCID: PMC6211302 DOI: 10.1016/j.jim.2014.04.007] [Citation(s) in RCA: 114] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Revised: 04/16/2014] [Accepted: 04/16/2014] [Indexed: 12/13/2022]
Abstract
Staphylococcus aureus - a commensal of the human skin, nares and gastrointestinal tract - is also a leading cause of bacterial skin and soft tissue infection (SSTIs), bacteremia, sepsis, peritonitis, pneumonia and endocarditis. Antibiotic-resistant strains, designated MRSA (methicillin-resistant S. aureus), are common and represent a therapeutic challenge. Current research and development efforts seek to address the challenge of MRSA infections through vaccines and immune therapeutics. Mice have been used as experimental models for S. aureus SSTI, bacteremia, sepsis, peritonitis and endocarditis. This work led to the identification of key virulence factors, candidate vaccine antigens or immune-therapeutics that still require human clinical testing to establish efficacy. Past failures of human clinical trials raised skepticism whether the mouse is an appropriate model for S. aureus disease in humans. S. aureus causes chronic-persistent infections that, even with antibiotic or surgical intervention, reoccur in humans and in mice. Determinants of S. aureus evasion from human innate and adaptive immune responses have been identified, however only some of these are relevant in mice. Future research must integrate these insights and refine the experimental mouse models for specific S. aureus diseases to accurately predict the failure or success for candidate vaccines and immune-therapeutics.
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Affiliation(s)
- Hwan Keun Kim
- Department of Microbiology, University of Chicago, 920 East 58th Street, Chicago, IL 60637, United States
| | - Dominique Missiakas
- Department of Microbiology, University of Chicago, 920 East 58th Street, Chicago, IL 60637, United States
| | - Olaf Schneewind
- Department of Microbiology, University of Chicago, 920 East 58th Street, Chicago, IL 60637, United States
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77
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The psmα locus regulates production of Staphylococcus aureus alpha-toxin during infection. Infect Immun 2014; 82:3350-8. [PMID: 24866799 DOI: 10.1128/iai.00089-14] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Staphylococcus aureus is a leading cause of human bacterial infection, causing a wide spectrum of disease ranging from skin and soft tissue infections to life-threatening pneumonia and sepsis. S. aureus toxins play an essential role in disease pathogenesis, contributing to both immunomodulation and host tissue injury. Prominent among these toxins are the membrane-active pore-forming cytolysin alpha-toxin (Hla) and the amphipathic α-helical phenol-soluble modulin (PSM) peptides. As deletion of either the hla or psm locus leads to a phenotypically similar virulence defect in skin and soft tissue infection, we sought to determine the relative contribution of each locus to disease pathogenesis. Here we show that production of Hla can be modulated by PSM expression. An S. aureus mutant lacking PSM expression exhibits a transcriptional delay in hla mRNA production and therefore fails to secrete normal levels of Hla at early phases of growth. This leads to attenuation of virulence in vitro and in murine skin and lung models of infection, correlating with reduced recovery of Hla from host tissues. Production of Hla and restoration of staphylococcal virulence can be achieved in the psm mutant by plasmid-driven overexpression of hla. Our study suggests the coordinated action of Hla and PSMs in host tissue during early pathogenesis, confirming a major role for Hla in epithelial injury during S. aureus infection. These findings highlight the possibility that therapeutics targeting PSM production may simultaneously prevent Hla-mediated tissue injury.
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78
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Omae Y, Sekimizu K, Kaito C. Identification of Staphylococcus aureus colony-spreading stimulatory factors from mammalian serum. PLoS One 2014; 9:e97670. [PMID: 24831518 PMCID: PMC4022729 DOI: 10.1371/journal.pone.0097670] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Accepted: 04/09/2014] [Indexed: 11/19/2022] Open
Abstract
Staphylococcus aureus forms giant colonies on soft-agar surfaces, which is called colony-spreading. In the present study, we searched for host factors that influence S. aureus colony-spreading activity. The addition of calf serum, porcine serum, or silkworm hemolymph to soft-agar medium stimulated S. aureus colony-spreading activity. Gel filtration column chromatography of calf serum produced a high molecular weight fraction and a low molecular weight fraction, both of which exhibited colony-spreading stimulatory activity. In the low molecular weight fraction, we identified the stimulatory factor as bovine serum albumin. The stimulatory fraction in the high molecular weight fraction was identified as high-density lipoprotein (HDL) particles. Delipidation of HDL abolished the stimulatory activity of HDL. Phosphatidylcholine, which is the major lipid component in HDL particles, stimulated the colony-spreading activity. Other phosphatidylcholine-containing lipoprotein particles, low-density lipoprotein and very low-density lipoprotein, also showed colony-spreading stimulatory activity. These findings suggest that S. aureus colony-spreading activity is stimulated by albumin and lipoprotein particles in mammalian serum.
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Affiliation(s)
- Yosuke Omae
- Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo, Japan
| | - Kazuhisa Sekimizu
- Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo, Japan
| | - Chikara Kaito
- Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo, Japan
- * E-mail:
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79
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Gonzalez DJ, Vuong L, Gonzalez IS, Keller N, McGrosso D, Hwang JH, Hung J, Zinkernagel A, Dixon JE, Dorrestein PC, Nizet V. Phenol soluble modulin (PSM) variants of community-associated methicillin-resistant Staphylococcus aureus (MRSA) captured using mass spectrometry-based molecular networking. Mol Cell Proteomics 2014; 13:1262-72. [PMID: 24567418 DOI: 10.1074/mcp.m113.031336] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Molecular genetic analysis indicates that the problematic human bacterial pathogen methicillin-resistant Staphylococcus aureus possesses more than 2000 open reading frames in its genome. This number of potential gene products, coupled with intrinsic mechanisms of posttranslational modification, endows methicillin-resistant Staphylococcus aureus with a highly complex biochemical repertoire. Recent proteomic and metabolomic advances have provided methodologies to better understand and characterize the biosynthetic factors released by microbial organisms. Here, the emerging tool of mass spectrometry-based molecular networking was used to visualize and map the repertoire of biosynthetic factors produced by a community-associated methicillin-resistant Staphylococcus aureus strain representative of the epidemic USA300 clone. In particular, the study focused on elucidating the complexity of the recently discovered phenol soluble modulin family of peptides when placed under various antibiotic treatment stresses. Novel PSM truncated variant peptides were captured, and the type of variants that were clustered by the molecular networks platform changed in response to the different antibiotic treatment conditions. After discovery, a group of the peptides were selected for functional analysis in vitro. The peptides displayed bioactive properties including the ability to induce proinflammatory responses in human THP-1 monocytes. Additionally, the tested peptides did not display antimicrobial activity as previously reported for other phenol soluble modulin truncated variants. Our findings reveal that the PSM family of peptides are quite structurally diverse, and suggest a single phenol soluble modulin parent peptide can functionally spawn differential bioactivities in response to various external stimuli.
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80
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Cheung GYC, Joo HS, Chatterjee SS, Otto M. Phenol-soluble modulins--critical determinants of staphylococcal virulence. FEMS Microbiol Rev 2014; 38:698-719. [PMID: 24372362 DOI: 10.1111/1574-6976.12057] [Citation(s) in RCA: 237] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2013] [Revised: 12/05/2013] [Accepted: 12/19/2013] [Indexed: 10/25/2022] Open
Abstract
Phenol-soluble modulins (PSMs) are a recently discovered family of amphipathic, alpha-helical peptides that have multiple roles in staphylococcal pathogenesis and contribute to a large extent to the pathogenic success of virulent staphylococci, such as Staphylococcus aureus. PSMs may cause lysis of many human cell types including leukocytes and erythrocytes, stimulate inflammatory responses, and contribute to biofilm development. PSMs appear to have an original role in the commensal lifestyle of staphylococci, where they facilitate growth and spreading on epithelial surfaces. Aggressive, cytolytic PSMs seem to have evolved from that original role and are mainly expressed in highly virulent S. aureus. Here, we will review the biochemistry, genetics, and role of PSMs in the commensal and pathogenic lifestyles of staphylococci, discuss how diversification of PSMs defines the aggressiveness of staphylococcal species, and evaluate potential avenues to target PSMs for drug development against staphylococcal infections.
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Affiliation(s)
- Gordon Y C Cheung
- Pathogen Molecular Genetics Section, Laboratory of Human Bacterial Pathogenesis, National Institute of Allergy and Infectious Diseases, The National Institutes of Health, Bethesda, MD, USA
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81
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Li S, Huang H, Rao X, Chen W, Wang Z, Hu X. Phenol-soluble modulins: novel virulence-associated peptides of staphylococci. Future Microbiol 2013; 9:203-16. [PMID: 24295365 DOI: 10.2217/fmb.13.153] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Phenol-soluble modulins (PSMs), a novel class of small peptides with an amphipathic α-helical structure and strong surfactant-like properties, are produced by most staphylococci, especially pathogenic Staphylococcus aureus and Staphylococcus epidermidis. PSMs can: induce the production of proinflammatory cytokines; recruit, activate and lyse neutrophils to help staphylococci evade immune damage; lyse erythrocytes and are associated with the hemolysis of staphylococcal disease; facilitate the structuring and detachment of staphylococcal biofilms and disseminate biofilm-associated infection; and kill competing microbes and act as weapons in interbacterial warfare. Therefore, PSMs are considered to be critical virulence-associated factors and to play important roles in the pathogenesis of staphylococci. This review summarizes the classification, structure, expression regulation and biological functions of PSMs. The possible means to prevent PSM-associated diseases are also outlined in order to emphasize the need to investigate PSMs as potential targets for drug and vaccine design against staphylococcal infections.
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Affiliation(s)
- Shu Li
- Department of Microbiology, Third Military Medical University, Chongqing 400038, China
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82
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Abstract
S. aureus is a frequent cause of chronic and therapy-refractory infections. The ability of S. aureus to invade different types of non-professional phagocytes, to escape from the host lysosomal degradation machinery and to persist within the intracellular location for long time periods are most likely essential steps in pathogenesis. During the course from acute to chronic infection the bacteria need to dynamically react to the environmental changes and to adapt to the intracellular environment. In this context the bacteria change to SCV-like phenotypes that exhibit some characteristics of stable SCV-mutants, like upregulation of adhesins and downregulation of toxins. The exact formation mechanism and further typical features of these dynamically forming SCVs are largely unknown. In this review, recent data on the essential steps to establish chronic infections will be summarized and the clinical consequences of the dynamic bacterial adaptation mechanisms will be discussed.
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83
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Abstract
PSMs are a recently discovered family of short, amphipathic, α-helical peptides in staphylococci. Several PSMs are key virulence determinants, particularly in highly virulent Staphylococcus aureus strains. PSMα peptides of S. aureus facilitate neutrophil lysis after phagocytosis, and are key contributors to several infection types, including skin infection and bacteremia. Furthermore, all PSMs contribute to biofilm structuring and the dissemination of biofilm-associated infection. Cytolytic PSMs as produced by S. aureus appear to have evolved from original functions in the non-infectious lifestyle of staphylococci. The surfactant properties of PSMs, which they all share, are believed to facilitate growth on epithelial surfaces. The basic role of PSMs in staphylococcal physiology is underscored, for example, by their exceptionally strict and direct control by quorum-sensing and the presence of a dedicated secretion system. Targeting PSMs for anti-staphylococcal drug development may be a promising approach to overcome the problems associated with widespread antibiotic resistance in staphylococci.
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Affiliation(s)
- Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Human Bacterial Pathogenesis, National Institute of Allergy and Infectious Diseases, The National Institutes of Health, Bethesda, MA, USA.
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84
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Grosz M, Kolter J, Paprotka K, Winkler AC, Schäfer D, Chatterjee SS, Geiger T, Wolz C, Ohlsen K, Otto M, Rudel T, Sinha B, Fraunholz M. Cytoplasmic replication of Staphylococcus aureus upon phagosomal escape triggered by phenol-soluble modulin α. Cell Microbiol 2013; 16:451-65. [PMID: 24164701 DOI: 10.1111/cmi.12233] [Citation(s) in RCA: 122] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Revised: 09/13/2013] [Accepted: 09/19/2013] [Indexed: 12/26/2022]
Abstract
Staphylococcus aureus is a Gram-positive human pathogen that is readily internalized by professional phagocytes such as macrophages and neutrophils but also by non-professional phagocytes such as epithelial or endothelial cells. Intracellular bacteria have been proposed to play a role in evasion of the innate immune system and may also lead to dissemination within migrating phagocytes. Further, S. aureus efficiently lyses host cells with a battery of cytolytic toxins. Recently, phenol-soluble modulins (PSM) have been identified to comprise a genus-specific family of cytolytic peptides. Of these the PSMα peptides have been implicated in killing polymorphonuclear leucocytes after phagocytosis. We questioned if the peptides were active in destroying endosomal membranes to avoid lysosomal killing of the pathogen and monitored integrity of infected host cell endosomes by measuring the acidity of the intracellular bacterial microenvironment via flow cytometry and by a reporter recruitment technique. Isogenic mutants of the methicillin-resistant S. aureus (MRSA) strains USA300 LAC, USA400 MW2 as well as the strongly cytolytic methicillin-sensitive strain 6850 were compared with their respective wild type strains. In all three genetic backgrounds, PSMα mutants were unable to escape from phagosomes in non-professional (293, HeLa, EAhy.926) and professional phagocytes (THP-1), whereas mutants in PSMβ and δ-toxin as well as β-toxin, phosphatidyl inositol-dependent phospholipase C and Panton Valentine leucotoxin escaped with efficiencies of the parental strains. S. aureus replicated intracellularly only in presence of a functional PSMα operon thereby illustrating that bacteria grow in the host cell cytoplasm upon phagosomal escape.
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Affiliation(s)
- Magdalena Grosz
- Department of Microbiology, University of Würzburg, Biocenter, Am Hubland, D-97074, Würzburg, Germany; Institute for Hygiene and Medical Microbiology, Josef-Schneider-Str. 2, Bldg. E1, D-97080, Würzburg, Germany
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85
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Genetic variation in the Staphylococcus aureus 8325 strain lineage revealed by whole-genome sequencing. PLoS One 2013; 8:e77122. [PMID: 24098817 PMCID: PMC3786944 DOI: 10.1371/journal.pone.0077122] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Accepted: 09/05/2013] [Indexed: 01/05/2023] Open
Abstract
Staphylococcus aureus strains of the 8325 lineage, especially 8325-4 and derivatives lacking prophage, have been used extensively for decades of research. We report herein the results of our deep sequence analysis of strain 8325-4. Assignment of sequence variants compared with the reference strain 8325 (NRS77/PS47) required correction of errors in the 8325 reference genome, and reassessment of variation previously attributed to chemical mutagenesis of the restriction-defective RN4220. Using an extensive strain pedigree analysis, we discovered that 8325-4 contains 16 single nucleotide polymorphisms (SNP) arising prior to the construction of RN4220. We identified 5 indels in 8325-4 compared with 8325. Three indels correspond to expected Φ11, 12, 13 excisions, one indel is explained by a sequence assembly artifact, and the final indel (Δ63bp) in the spa-sarS intergenic region is common to only a sub-lineage of 8325-4 strains including SH1000. This deletion was found to significantly decrease (75%) steady state sarS but not spa transcript levels in post-exponential phase. The sub-lineage 8325-4 was also found to harbor 4 additional SNPs. We also found large sequence variation between 8325, 8325-4 and RN4220 in a cluster of repetitive hypothetical proteins (SA0282 homologs) near the Ess secretion cluster. The overall 8325-4 SNP set results in 17 alterations within coding sequences. Remarkably, we discovered that all tested strains of the 8325-4 lineage lack phenol soluble modulin α3 (PSMα3), a virulence determinant implicated in neutrophil chemotaxis, biofilm architecture and surface spreading. Collectively, our results clarify and define the 8325-4 pedigree and reveal clear evidence that mutations existing throughout all branches of this lineage, including the widely used RN6390 and SH1000 strains, could conceivably impact virulence regulation.
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86
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Abstract
Staphylococcus aureus is an important human pathogen and a leading cause of death worldwide. Phenol-soluble modulins (PSMs) have recently emerged as a novel toxin family defining the virulence potential of highly aggressive S. aureus isolates. PSMs have multiple roles in staphylococcal pathogenesis, causing lysis of red and white blood cells, stimulating inflammatory responses and contributing to biofilm development and the dissemination of biofilm-associated infections. Moreover, the pronounced capacity of PSMs to kill human neutrophils after phagocytosis might explain failures in the development of anti-staphylococcal vaccines. Here, we discuss recent progress made in our understanding of the biochemical and genetic properties of PSMs and their role in S. aureus pathogenesis, and suggest potential avenues to target PSMs for the development of anti-staphylococcal drugs.
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87
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Cheung GYC, Kretschmer D, Queck SY, Joo HS, Wang R, Duong AC, Nguyen TH, Bach THL, Porter AR, DeLeo FR, Peschel A, Otto M. Insight into structure-function relationship in phenol-soluble modulins using an alanine screen of the phenol-soluble modulin (PSM) α3 peptide. FASEB J 2013; 28:153-61. [PMID: 24008753 DOI: 10.1096/fj.13-232041] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Phenol-soluble modulins (PSMs) are a family of peptides with multiple functions in staphylococcal pathogenesis. To gain insight into the structural features affecting PSM functions, we analyzed an alanine substitution library of PSMα3, a strongly cytolytic and proinflammatory PSM of Staphylococcus aureus with a significant contribution to S. aureus virulence. Lysine residues were essential for both receptor-dependent proinflammatory and receptor-independent cytolytic activities. Both phenotypes also required additional structural features, with the C terminus being crucial for receptor activation. Biofilm formation was affected mostly by hydrophobic amino acid positions, suggesting that the capacity to disrupt hydrophobic interactions is responsible for the effect of PSMs on biofilm structure. Antimicrobial activity, absent from natural PSMα3, could be created by the exchange of large hydrophobic side chains, indicating that PSMα3 has evolved to exhibit cytolytic rather than antimicrobial activity. In addition to gaining insight into the structure-function relationship in PSMs, our study identifies nontoxic PSMα3 derivatives for active vaccination strategies and lays the foundation for future efforts aimed to understand the biological role of PSM recognition by innate host defense.
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Affiliation(s)
- Gordon Y C Cheung
- 3National Institute of Allergy and Infectious Diseases, 9000 Rockville Pike, Bldg. 33 1W10, Bethesda, MD 20892, USA.
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88
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Surewaard BGJ, de Haas CJC, Vervoort F, Rigby KM, DeLeo FR, Otto M, van Strijp JAG, Nijland R. Staphylococcal alpha-phenol soluble modulins contribute to neutrophil lysis after phagocytosis. Cell Microbiol 2013; 15:1427-37. [PMID: 23470014 PMCID: PMC4784422 DOI: 10.1111/cmi.12130] [Citation(s) in RCA: 131] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Revised: 02/07/2013] [Accepted: 02/20/2013] [Indexed: 01/01/2023]
Abstract
Staphylococcus aureus community-acquired (CA) MRSA strains are highly virulent and can cause infections in otherwise healthy individuals. The most important mechanism of the host for clearing S. aureus is phagocytosis by neutrophils and subsequent killing of the pathogen. Especially CA-MRSA strains are very efficient in circumventing this neutrophil killing. Interestingly, only a relative small number of virulence factors have been associated with CA-MRSA, one of which are the phenol soluble modulins (PSMs). We have recently shown that the PSMs are functionally inhibited by serum lipoproteins, indicating that PSMs may exert their cytolytic function primarily in the intracellular environment. To further investigate the intracellular role of the PSMs we measured the effect of the α-type and β-type PSMs on neutrophil killing after phagocytosis. Using fluorescently labelled S. aureus, we measured bacterial survival after phagocytosis in a plate reader, which was employed next to flow cytometry and time-lapse microscopy. Phagocytosis of the CA-MRSA strain MW2 by human neutrophils resulted in rapid host cell death. Using mutant strains of MW2, we demonstrated that in the presence of serum, the intracellular expression of only the psmα operon is both necessary and sufficient for both increased neutrophil cell death and increased survival of S. aureus. Our results identify PSMα peptides as prominent contributors to killing of neutrophils after phagocytosis, a finding with major implications for our understanding of S. aureus pathogenesis and strategies for S. aureus vaccine development.
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Affiliation(s)
- BGJ Surewaard
- Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - CJC de Haas
- Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - F Vervoort
- Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - KM Rigby
- Laboratory of Human Bacterial Pathogenesis, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Hamilton, Montana, USA
| | - FR DeLeo
- Laboratory of Human Bacterial Pathogenesis, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Hamilton, Montana, USA
| | - M Otto
- Laboratory of Human Bacterial Pathogenesis, National Institute of Allergy and Infectious Diseases (NIAID), The National Institutes of Health (NIH), Bethesda, MD, USA
| | - JAG van Strijp
- Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - R Nijland
- Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
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89
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Surewaard BGJ, van Strijp JAG, Nijland R. Studying interactions of Staphylococcus aureus with neutrophils by flow cytometry and time lapse microscopy. J Vis Exp 2013:e50788. [PMID: 23893048 DOI: 10.3791/50788] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
We present methods to study the effect of phenol soluble modulins (PSMs) and other toxins produced and secreted by Staphylococcus aureus on neutrophils. To study the effects of the PSMs on neutrophils we isolate fresh neutrophils using density gradient centrifugation. These neutrophils are loaded with a dye that fluoresces upon calcium mobilization. The activation of neutrophils by PSMs initiates a rapid and transient increase in the free intracellular calcium concentration. In a flow cytometry experiment this rapid mobilization can be measured by monitoring the fluorescence of a pre-loaded dye that reacts to the increased concentration of free Ca(2+). Using this method we can determine the PSM concentration necessary to activate the neutrophil, and measure the effects of specific and general inhibitors of the neutrophil activation. To investigate the expression of the PSMs in the intracellular space, we have constructed reporter fusions of the promoter of the PSMα operon to GFP. When these reporter strains of S. aureus are phagocytosed by neutrophils, the induction of expression can be observed using fluorescence microscopy.
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Affiliation(s)
- Bas G J Surewaard
- Medical Microbiology, University Medical Center Utrecht, The Netherlands
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90
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Spaan AN, Surewaard BGJ, Nijland R, van Strijp JAG. Neutrophils versus Staphylococcus aureus: a biological tug of war. Annu Rev Microbiol 2013; 67:629-50. [PMID: 23834243 DOI: 10.1146/annurev-micro-092412-155746] [Citation(s) in RCA: 236] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The pathogen Staphylococcus aureus is well adapted to its human host. Neutrophil-mediated killing is a crucial defense system against S. aureus; however, the pathogen has evolved many strategies to resist killing. We first describe the discrete steps of neutrophil activation and migration to the site of infection and the killing of microbes by neutrophils in general. We then highlight the different approaches utilized by S. aureus to resist the different steps of neutrophil attack. Various molecules are discussed in their evolutionary context. Most of the molecules secreted by S. aureus to combat neutrophil attacks at the site of infection show clear human specificity. Many elements of human neutrophil defenses appear redundant, and so the evasion strategies of staphylococci display redundant functions as well. All efforts by S. aureus to resist neutrophil-mediated killing stress the importance of these mechanisms in the pathophysiology of staphylococcal diseases. However, the highly human-specific nature of most host-pathogen interactions hinders the in vivo establishment of their contribution to staphylococcal pathophysiology.
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Affiliation(s)
- András N Spaan
- Department of Medical Microbiology, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands; , , ,
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91
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Rasigade JP, Trouillet-Assant S, Ferry T, Diep BA, Sapin A, Lhoste Y, Ranfaing J, Badiou C, Benito Y, Bes M, Couzon F, Tigaud S, Lina G, Etienne J, Vandenesch F, Laurent F. PSMs of hypervirulent Staphylococcus aureus act as intracellular toxins that kill infected osteoblasts. PLoS One 2013; 8:e63176. [PMID: 23690994 PMCID: PMC3653922 DOI: 10.1371/journal.pone.0063176] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Accepted: 03/29/2013] [Indexed: 12/21/2022] Open
Abstract
Epidemic community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) is associated with more severe and acute forms of osteomyelitis than healthcare-associated (HA-) MRSA. Although S. aureus is now recognized as a facultative intracellular pathogen, the contribution of osteoblast invasion by CA-MRSA to the pathogenesis of osteomyelitis is unknown. Using an ex vivo model of intracellular infection of human osteoblasts, we demonstrated that CA-MRSA strains of diverse lineages share an enhanced ability to kill infected osteoblasts compared to HA-MRSA. Cytotoxicity comparisons of CA-MRSA isogenic deletion mutants revealed that phenol-soluble modulins (PSMs), a class of membrane-damaging exoproteins that are expressed at higher levels in CA-MRSA than in HA-MRSA, are involved in this osteoblast killing, whereas other major CA-MRSA virulence determinants, the Panton-Valentine leukocidin and alpha-toxin, are not involved. Similarly, functional agr and sarA regulators, which control the expression of PSMs and alpha-toxin, were required for the expression of the intracellular cytotoxic phenotype by CA-MRSA, whereas the saeRS regulator, which controls the expression of alpha-toxin but not PSMs, had no impact on cytotoxicity. Finally, PSM transcript levels determined by quantitative reverse-transcriptase PCR were significantly higher in CA-MRSA than in HA-MRSA strains and associated with cell damage in MRSA-infected osteoblasts. These findings provide new insights into the pathogenesis of severe CA-MRSA osteomyelitis and unravel a novel virulence strategy of CA-MRSA, based on the invasion and subsequent killing of osteoblasts by PSMs acting as intracellular toxins.
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Affiliation(s)
- Jean-Philippe Rasigade
- Institut National de la Santé et de la Recherche Médicale (INSERM) U1111, University of Lyon, Lyon, France
- National Reference Center for Staphylococci, Hospices Civils de Lyon, Bron, France
- Department of Clinical Microbiology, Northern Hospital Group, Hospices Civils de Lyon, Lyon, France
- * E-mail:
| | - Sophie Trouillet-Assant
- Institut National de la Santé et de la Recherche Médicale (INSERM) U1111, University of Lyon, Lyon, France
| | - Tristan Ferry
- Institut National de la Santé et de la Recherche Médicale (INSERM) U1111, University of Lyon, Lyon, France
| | - Binh An Diep
- Division of Infectious Diseases, Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Anaïs Sapin
- Department of Clinical Microbiology, Northern Hospital Group, Hospices Civils de Lyon, Lyon, France
| | - Yannick Lhoste
- Department of Clinical Microbiology, Northern Hospital Group, Hospices Civils de Lyon, Lyon, France
| | - Jérémy Ranfaing
- Institut National de la Santé et de la Recherche Médicale (INSERM) U1111, University of Lyon, Lyon, France
| | - Cédric Badiou
- Institut National de la Santé et de la Recherche Médicale (INSERM) U1111, University of Lyon, Lyon, France
| | - Yvonne Benito
- National Reference Center for Staphylococci, Hospices Civils de Lyon, Bron, France
| | - Michèle Bes
- National Reference Center for Staphylococci, Hospices Civils de Lyon, Bron, France
| | - Florence Couzon
- Institut National de la Santé et de la Recherche Médicale (INSERM) U1111, University of Lyon, Lyon, France
| | - Sylvestre Tigaud
- Department of Clinical Microbiology, Northern Hospital Group, Hospices Civils de Lyon, Lyon, France
| | - Gérard Lina
- Institut National de la Santé et de la Recherche Médicale (INSERM) U1111, University of Lyon, Lyon, France
- National Reference Center for Staphylococci, Hospices Civils de Lyon, Bron, France
| | - Jérôme Etienne
- Institut National de la Santé et de la Recherche Médicale (INSERM) U1111, University of Lyon, Lyon, France
- National Reference Center for Staphylococci, Hospices Civils de Lyon, Bron, France
| | - François Vandenesch
- Institut National de la Santé et de la Recherche Médicale (INSERM) U1111, University of Lyon, Lyon, France
- National Reference Center for Staphylococci, Hospices Civils de Lyon, Bron, France
| | - Frédéric Laurent
- Institut National de la Santé et de la Recherche Médicale (INSERM) U1111, University of Lyon, Lyon, France
- National Reference Center for Staphylococci, Hospices Civils de Lyon, Bron, France
- Department of Clinical Microbiology, Northern Hospital Group, Hospices Civils de Lyon, Lyon, France
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92
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Nosocomial infections after severe trauma are associated with lower apolipoproteins B and AII. J Trauma Acute Care Surg 2013; 74:1067-73. [PMID: 23511146 DOI: 10.1097/ta.0b013e3182826be0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Infection after severe trauma is a significant cause of morbidity and mortality days to weeks after the initial injury. Apolipoproteins play important roles in host defense and circulating concentrations are altered by the acute inflammatory response. The purpose of this study was to determine if patients who acquire infection after severe trauma have significantly lower apolipoprotein levels than trauma patients who do not become infected. METHODS We conducted a case-control study on a prospectively identified cohort of adult patients admitted to our intensive care unit after severe trauma (Injury Severity Score ≥ 16). We compared plasma apolipoprotein levels between patients who acquired an infection within 30 days after trauma (cases) and those that remained infection free (controls). RESULTS Of 40 patients experiencing severe trauma, we identified 22 cases that developed an infection within 30 days after injury. Cases had significantly lower posttrauma plasma levels of apolipoprotein B (p = 0.02) and apolipoprotein AII (p = 0.02) compared with controls. Consistent with previous studies, cases also received greater volumes of crystalloid infusions (p < 0.01) and blood transfusions (p < 0.01). Cases also had a more profound inflammatory response as measured by interleukin 6 levels (p = 0.02). CONCLUSION Infection after severe trauma is associated with decreased circulating apolipoproteins as compared with uninfected controls. Profoundly decreased plasma apolipoproteins B and AII could potentially contribute to the impaired immunity after severe trauma. Apolipoproteins are potential targets for identifying those patients at risk of infection after trauma and for interventions aimed at preventing nosocomial infections. LEVEL OF EVIDENCE Prognostic study, level III.
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93
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Abstract
While infections with methicillin-resistant Staphylococcus aureus (MRSA) were traditionally restricted to the hospital setting, novel MRSA strains emerged over the last two decades that have the capacity to infect otherwise healthy people outside of the hospital setting. These community-associated (CA-)MRSA strains combine methicillin resistance with enhanced virulence and fitness. Interestingly, CA-MRSA strains emerged globally and from different backgrounds, indicating that the "trade-off" between maintaining sufficient levels of methicillin resistance and obtaining enhanced virulence at a low fitness cost was achieved on several occasions in convergent evolution. However, frequently this process comprised similar changes. First and foremost, all CA-MRSA strains typically carry a novel type of methicillin resistance locus that appears to cause less of a fitness burden. Additionally, acquisition of specific toxin genes, most notably that encoding Panton-Valentine leukocidin (PVL), and adaptation of gene expression of genome-encoded toxins, such as alpha-toxin and phenol-soluble modulins (PSMs), further contributed to the evolution of CA-MRSA. Finally, the exceptional epidemiological success of the USA300 CA-MRSA clone in particular may have been due to yet another gene acquisition, namely that of the speG gene, which is located on the arginine catabolic mobile element (ACME) and involved in detoxifying harmful host-derived polyamines.
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Affiliation(s)
- Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Human Bacterial Pathogenesis, National Institute of Allergy and Infectious Diseases, The National Institutes of Health, Bethesda, MD, USA.
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94
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Staphylococcus aureus elaborates leukocidin AB to mediate escape from within human neutrophils. Infect Immun 2013; 81:1830-41. [PMID: 23509138 DOI: 10.1128/iai.00095-13] [Citation(s) in RCA: 110] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) strains of the pulsed-field type USA300 are primarily responsible for the current community-associated epidemic of MRSA infections in the United States. The success of USA300 is partly attributed to the ability of the pathogen to avoid destruction by human neutrophils (polymorphonuclear leukocytes [PMNs]), which are crucial to the host immune response to S. aureus infection. In this work, we investigated the contribution of bicomponent pore-forming toxins to the ability of USA300 to withstand attack from primary human PMNs. We demonstrate that in vitro growth conditions influence the expression, production, and availability of leukotoxins by USA300, which in turn impact the cytotoxic potential of this clone toward PMNs. Interestingly, we also found that upon exposure to PMNs, USA300 preferentially activates the promoter of the lukAB operon, which encodes the recently identified leukocidin AB (LukAB). LukAB elaborated by extracellular S. aureus forms pores in the plasma membrane of PMNs, leading to PMN lysis, highlighting a contribution of LukAB to USA300 virulence. We now show that LukAB also facilitates the escape of bacteria engulfed within PMNs, in turn enabling the replication and outgrowth of S. aureus. Together, these results suggest that upon encountering PMNs S. aureus induces the production of LukAB, which serves as an extra- and intracellular weapon to protect the bacterium from destruction by human PMNs.
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95
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Abstract
Widespread antibiotic resistance among important bacterial pathogens such as Staphylococcus aureus1 calls for alternative routes of drug development. Interfering with critical virulence determinants is considered a promising novel approach to control bacterial infection2. Phenol-soluble modulins (PSMs) are peptide toxins with multiple key roles in pathogenesis3–5 and a major impact on the ability of highly virulent S. aureus to cause disease3,6. However, targeting PSMs for therapeutic intervention is hampered by their multitude and diversity. Here, we report that an ABC transporter with previously unknown function is responsible for the export of all PSM classes, thus representing a single target to interfere simultaneously with the production of all PSMs. The transporter had a strong effect on virulence phenotypes, such as neutrophil lysis, and the development of S. aureus infection, similar in extent to the sum of all PSMs. Furthermore, it proved essential for bacterial growth. Moreover, it protected the producer from the antimicrobial activity of secreted PSMs and contributed to defense against PSM-mediated bacterial interference. Our study reveals a non-canonical, dedicated secretion mechanism for an important toxin class and identifies this mechanism as a comprehensive potential target for the development of drugs efficiently inhibiting growth and virulence of pathogenic staphylococci.
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96
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Hall PR, Elmore BO, Spang CH, Alexander SM, Manifold-Wheeler BC, Castleman MJ, Daly SM, Peterson MM, Sully EK, Femling JK, Otto M, Horswill AR, Timmins GS, Gresham HD. Nox2 modification of LDL is essential for optimal apolipoprotein B-mediated control of agr type III Staphylococcus aureus quorum-sensing. PLoS Pathog 2013; 9:e1003166. [PMID: 23459693 PMCID: PMC3573103 DOI: 10.1371/journal.ppat.1003166] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Accepted: 12/17/2012] [Indexed: 12/29/2022] Open
Abstract
Staphylococcus aureus contains an autoinducing quorum-sensing system encoded within the agr operon that coordinates expression of virulence genes required for invasive infection. Allelic variation within agr has generated four agr specific groups, agr I-IV, each of which secretes a distinct autoinducing peptide pheromone (AIP1-4) that drives agr signaling. Because agr signaling mediates a phenotypic change in this pathogen from an adherent colonizing phenotype to one associated with considerable tissue injury and invasiveness, we postulated that a significant contribution to host defense against tissue damaging and invasive infections could be provided by innate immune mechanisms that antagonize agr signaling. We determined whether two host defense factors that inhibit AIP1-induced agrI signaling, Nox2 and apolipoprotein B (apoB), also contribute to innate control of AIP3-induced agrIII signaling. We hypothesized that apoB and Nox2 would function differently against AIP3, which differs from AIP1 in amino acid sequence and length. Here we show that unlike AIP1, AIP3 is resistant to direct oxidant inactivation by Nox2 characteristic ROS. Rather, the contribution of Nox2 to defense against agrIII signaling is through oxidation of LDL. ApoB in the context of oxLDL, and not LDL, provides optimal host defense against S. aureus agrIII infection by binding the secreted signaling peptide, AIP3, and preventing expression of the agr-driven virulence factors which mediate invasive infection. ApoB within the context of oxLDL also binds AIP 1-4 and oxLDL antagonizes agr signaling by all four agr alleles. Our results suggest that Nox2-mediated oxidation of LDL facilitates a conformational change in apoB to one sufficient for binding and sequestration of all four AIPs, demonstrating the interdependence of apoB and Nox2 in host defense against agr signaling. These data reveal a novel role for oxLDL in host defense against S. aureus quorum-sensing signaling.
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Affiliation(s)
- Pamela R Hall
- Department of Pharmaceutical Sciences, University of New Mexico College of Pharmacy, Albuquerque, New Mexico, USA.
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97
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Gao W, Cameron DR, Davies JK, Kostoulias X, Stepnell J, Tuck KL, Yeaman MR, Peleg AY, Stinear TP, Howden BP. The RpoB H₄₈₁Y rifampicin resistance mutation and an active stringent response reduce virulence and increase resistance to innate immune responses in Staphylococcus aureus. J Infect Dis 2012; 207:929-39. [PMID: 23255563 DOI: 10.1093/infdis/jis772] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The occurrence of mutations in methicillin-resistant Staphylococcus aureus (MRSA) during persistent infection leads to antimicrobial resistance but may also impact host-pathogen interactions. Here, we investigate the host-pathogen consequences of 2 mutations arising in clinical MRSA during persistent infection: RpoB H₄₈₁Y, which is linked to rifampicin resistance, and RelA F₁₂₈Y, which is associated with an active stringent response. Allelic exchange experiments showed that both mutations cause global transcriptional changes, leading to upregulation of capsule production, with attenuated virulence in a murine bacteremia model and reduced susceptibility to both antimicrobial peptides and whole-blood killing. Disruption of capsule biosynthesis reversed these impacts on innate immune function. These data clearly link MRSA persistence and reduced virulence to the same mechanisms that alter antimicrobial susceptibility. Our study highlights the wider consequences of suboptimal antimicrobial use, where drug resistance and immune escape mechanisms coevolve, thus increasing the likelihood of treatment failure.
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Affiliation(s)
- Wei Gao
- Infectious Diseases Department, Austin Centre for Infection Research, University of Melbourne, Australia
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98
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Geiger T, Francois P, Liebeke M, Fraunholz M, Goerke C, Krismer B, Schrenzel J, Lalk M, Wolz C. The stringent response of Staphylococcus aureus and its impact on survival after phagocytosis through the induction of intracellular PSMs expression. PLoS Pathog 2012; 8:e1003016. [PMID: 23209405 PMCID: PMC3510239 DOI: 10.1371/journal.ppat.1003016] [Citation(s) in RCA: 168] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Accepted: 09/22/2012] [Indexed: 02/07/2023] Open
Abstract
The stringent response is initiated by rapid (p)ppGpp synthesis, which leads to a profound reprogramming of gene expression in most bacteria. The stringent phenotype seems to be species specific and may be mediated by fundamentally different molecular mechanisms. In Staphylococcus aureus, (p)ppGpp synthesis upon amino acid deprivation is achieved through the synthase domain of the bifunctional enzyme RSH (RelA/SpoT homolog). In several firmicutes, a direct link between stringent response and the CodY regulon was proposed. Wild-type strain HG001, rsh(Syn), codY and rsh(Syn), codY double mutants were analyzed by transcriptome analysis to delineate different consequences of RSH-dependent (p)ppGpp synthesis after induction of the stringent response by amino-acid deprivation. Under these conditions genes coding for major components of the protein synthesis machinery and nucleotide metabolism were down-regulated only in rsh positive strains. Genes which became activated upon (p)ppGpp induction are mostly regulated indirectly via de-repression of the GTP-responsive repressor CodY. Only seven genes, including those coding for the cytotoxic phenol-soluble modulins (PSMs), were found to be up-regulated via RSH independently of CodY. qtRT-PCR analyses of hallmark genes of the stringent response indicate that an RSH activating stringent condition is induced after uptake of S. aureus in human polymorphonuclear neutrophils (PMNs). The RSH activity in turn is crucial for intracellular expression of psms. Accordingly, rsh(Syn) and rsh(Syn), codY mutants were less able to survive after phagocytosis similar to psm mutants. Intraphagosomal induction of psmα1-4 and/or psmβ1,2 could complement the survival of the rsh(Syn) mutant. Thus, an active RSH synthase is required for intracellular psm expression which contributes to survival after phagocytosis.
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Affiliation(s)
- Tobias Geiger
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Tübingen, Germany
| | - Patrice Francois
- Genomic Research Laboratory, Infectious Diseases Service, Geneva University Hospitals and the University of Geneva, Geneva, Switzerland
| | - Manuel Liebeke
- Institute of Pharmaceutical Biology, Ernst-Moritz-Arndt University of Greifswald, Greifswald, Germany
| | - Martin Fraunholz
- Department of Microbiology, Biocenter, University of Würzburg, Würzburg, Germany
| | - Christiane Goerke
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Tübingen, Germany
| | - Bernhard Krismer
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Tübingen, Germany
| | - Jacques Schrenzel
- Genomic Research Laboratory, Infectious Diseases Service, Geneva University Hospitals and the University of Geneva, Geneva, Switzerland
| | - Michael Lalk
- Institute of Pharmaceutical Biology, Ernst-Moritz-Arndt University of Greifswald, Greifswald, Germany
| | - Christiane Wolz
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Tübingen, Germany
- * E-mail:
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