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Nygaard TK, Borgogna TR, Pallister KB, Predtechenskaya M, Burroughs OS, Gao A, Lubick EG, Voyich JM. The Relative Importance of Cytotoxins Produced by Methicillin-Resistant Staphylococcus aureus Strain USA300 for Causing Human PMN Destruction. Microorganisms 2024; 12:1782. [PMID: 39338457 PMCID: PMC11434515 DOI: 10.3390/microorganisms12091782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2024] [Revised: 08/20/2024] [Accepted: 08/22/2024] [Indexed: 09/30/2024] Open
Abstract
Staphylococcus aureus (S. aureus) is a prominent Gram-positive bacterial pathogen that expresses numerous cytotoxins known to target human polymorphonuclear leukocytes (PMNs or neutrophils). These include leukocidin G/H (LukGH, also known as LukAB), the Panton-Valentine leukocidin (PVL), γ-hemolysin A/B (HlgAB), γ-hemolysin B/C (HlgBC), leukocidin E/D (LukED), α-hemolysin (Hla), and the phenol-soluble modulin-α peptides (PSMα). However, the relative contribution of each of these cytotoxins in causing human PMN lysis is not clear. In this study, we used a library of cytotoxin deletion mutants in the clinically relevant methicillin-resistant S. aureus (MRSA) isolate LAC (strain ST8:USA300) to determine the relative importance of each for causing human PMN lysis upon exposure to extracellular components as well as following phagocytosis. Using flow cytometry to examine plasma membrane permeability and assays quantifying lactose dehydrogenase release, we found that PVL was the dominant extracellular factor causing human PMN lysis produced by USA300. In contrast, LukGH was the most important cytotoxin causing human PMN lysis immediately following phagocytosis with contributions from the other bicomponent leukocidins only observed at later time points. These results not only clarify the relative importance of different USA300 cytotoxins for causing human PMN destruction but also demonstrate how two apparently redundant virulence factors play distinctive roles in promoting S. aureus pathogenesis.
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Affiliation(s)
- Tyler K Nygaard
- Department of Microbiology Cell Biology, Montana State University, Bozeman, MT 59718, USA
| | - Timothy R Borgogna
- Department of Microbiology Cell Biology, Montana State University, Bozeman, MT 59718, USA
| | - Kyler B Pallister
- Department of Microbiology Cell Biology, Montana State University, Bozeman, MT 59718, USA
| | - Maria Predtechenskaya
- Department of Microbiology Cell Biology, Montana State University, Bozeman, MT 59718, USA
| | - Owen S Burroughs
- Department of Microbiology Cell Biology, Montana State University, Bozeman, MT 59718, USA
| | - Annika Gao
- Department of Microbiology Cell Biology, Montana State University, Bozeman, MT 59718, USA
| | - Evan G Lubick
- Department of Microbiology Cell Biology, Montana State University, Bozeman, MT 59718, USA
| | - Jovanka M Voyich
- Department of Microbiology Cell Biology, Montana State University, Bozeman, MT 59718, USA
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2
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Konaklieva MI, Plotkin BJ. Targeting host-specific metabolic pathways-opportunities and challenges for anti-infective therapy. Front Mol Biosci 2024; 11:1338567. [PMID: 38455763 PMCID: PMC10918472 DOI: 10.3389/fmolb.2024.1338567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Accepted: 01/24/2024] [Indexed: 03/09/2024] Open
Abstract
Microorganisms can takeover critical metabolic pathways in host cells to fuel their replication. This interaction provides an opportunity to target host metabolic pathways, in addition to the pathogen-specific ones, in the development of antimicrobials. Host-directed therapy (HDT) is an emerging strategy of anti-infective therapy, which targets host cell metabolism utilized by facultative and obligate intracellular pathogens for entry, replication, egress or persistence of infected host cells. This review provides an overview of the host lipid metabolism and links it to the challenges in the development of HDTs for viral and bacterial infections, where pathogens are using important for the host lipid enzymes, or producing their own analogous of lecithin-cholesterol acyltransferase (LCAT) and lipoprotein lipase (LPL) thus interfering with the human host's lipid metabolism.
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Affiliation(s)
| | - Balbina J. Plotkin
- Department of Microbiology and Immunology, Midwestern University, Downers Grove, IL, United States
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3
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Kristoffersen K, Hansen KH, Andreasen M. Differential Effects of Lipid Bilayers on αPSM Peptide Functional Amyloid Formation. Int J Mol Sci 2023; 25:102. [PMID: 38203273 PMCID: PMC10779341 DOI: 10.3390/ijms25010102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 12/16/2023] [Accepted: 12/17/2023] [Indexed: 01/12/2024] Open
Abstract
Phenol-soluble modulins (PSMs) are key virulence factors of S. aureus, and they comprise the structural scaffold of biofilm as they self-assemble into functional amyloids. They have been shown to interact with cell membranes as they display toxicity towards human cells through cell lysis, with αPSM3 being the most cytotoxic. In addition to causing cell lysis in mammalian cells, PSMs have also been shown to interact with bacterial cell membranes through antimicrobial effects. Here, we present a study on the effects of lipid bilayers on the aggregation mechanism of αPSM using chemical kinetics to study the effects of lipid vesicles on the aggregation kinetics and using circular dichroism (CD) spectroscopy, Fourier-transform infrared (FTIR) spectroscopy and transmission electron microscopy (TEM) to investigate the corresponding secondary structure of the aggregates. We found that the effects of lipid bilayers on αPSM aggregation were not homogeneous between lipid type and αPSM peptides, although none of the lipids caused changes in the dominating aggregation mechanism. In the case of αPSM3, all types of lipids slowed down aggregation to a varying degree, with 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) having the most pronounced effect. For αPSM1, lipids had opposite effects, where DOPC decelerated aggregation and lipopolysaccharide (LPS) accelerated the aggregation, while 1,2-dioleoyl-sn-glycero-3-phospho-rac-(1-glycerol) (DOPG) had no effect. For αPSM4, both DOPG and LPS accelerated the aggregation, but only at high concentration, while DOPC showed no effect. None of the lipids was capable of inducing aggregation of αPSM2. Our data reveal a complex interaction pattern between PSMs peptides and lipid bilayers that causes changes in the aggregation kinetics by affecting different kinetic parameters along with only subtle changes in morphology.
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Affiliation(s)
| | | | - Maria Andreasen
- Department of Biomedicine, Aarhus University, Willhelm Meyer’s Allé 3, 8000 Aarhus, Denmark
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4
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Wang X, Uppu DSSM, Dickey SW, Burgin DJ, Otto M, Lee JC. Staphylococcus aureus delta toxin modulates both extracellular membrane vesicle biogenesis and amyloid formation. mBio 2023; 14:e0174823. [PMID: 37795985 PMCID: PMC10653798 DOI: 10.1128/mbio.01748-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 08/15/2023] [Indexed: 10/06/2023] Open
Abstract
IMPORTANCE Extracellular membrane vesicles (MVs) produced by Staphylococcus aureus in planktonic cultures encapsulate a diverse cargo of bacterial proteins, nucleic acids, and glycopolymers that are protected from destruction by external factors. δ-toxin, a member of the phenol soluble modulin family, was shown to be critical for MV biogenesis. Amyloid fibrils co-purified with MVs generated by virulent, community-acquired S. aureus strains, and fibril formation was dependent on expression of the S. aureus δ-toxin gene (hld). Mass spectrometry data confirmed that the amyloid fibrils were comprised of δ-toxin. Although S. aureus MVs were produced in vivo in a localized murine infection model, amyloid fibrils were not observed in the in vivo setting. Our findings provide critical insights into staphylococcal factors involved in MV biogenesis and amyloid formation.
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Affiliation(s)
- Xiaogang Wang
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Divakara SSM Uppu
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Seth W. Dickey
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, USA
- Department of Veterinary Medicine, Virginia-Maryland Regional College of Veterinary Medicine,University of Maryland, Bethesda, Maryland, USA
| | - Dylan J. Burgin
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, USA
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, USA
| | - Jean C. Lee
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
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5
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Peiseler M, Araujo David B, Zindel J, Surewaard BGJ, Lee WY, Heymann F, Nusse Y, Castanheira FVS, Shim R, Guillot A, Bruneau A, Atif J, Perciani C, Ohland C, Ganguli Mukherjee P, Niehrs A, Thuenauer R, Altfeld M, Amrein M, Liu Z, Gordon PMK, McCoy K, Deniset J, MacParland S, Ginhoux F, Tacke F, Kubes P. Kupffer cell-like syncytia replenish resident macrophage function in the fibrotic liver. Science 2023; 381:eabq5202. [PMID: 37676943 DOI: 10.1126/science.abq5202] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 07/13/2023] [Indexed: 09/09/2023]
Abstract
Kupffer cells (KCs) are localized in liver sinusoids but extend pseudopods to parenchymal cells to maintain their identity and serve as the body's central bacterial filter. Liver cirrhosis drastically alters vascular architecture, but how KCs adapt is unclear. We used a mouse model of liver fibrosis and human tissue to examine immune adaptation. Fibrosis forced KCs to lose contact with parenchymal cells, down-regulating "KC identity," which rendered them incapable of clearing bacteria. Commensals stimulated the recruitment of monocytes through CD44 to a spatially distinct vascular compartment. There, recruited monocytes formed large aggregates of multinucleated cells (syncytia) that expressed phenotypical KC markers and displayed enhanced bacterial capture ability. Syncytia formed via CD36 and were observed in human cirrhosis as a possible antimicrobial defense that evolved with fibrosis.
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Affiliation(s)
- Moritz Peiseler
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
- Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Department of Hepatology and Gastroenterology, Charité Universitätsmedizin Berlin, Campus Virchow Klinikum and Campus Charité Mitte, Berlin, Germany
- Berlin Institute of Health (BIH), Berlin, Germany
| | - Bruna Araujo David
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
- Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Joel Zindel
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
- Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Department of Visceral Surgery and Medicine, Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Bas G J Surewaard
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
- Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Woo-Yong Lee
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
- Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Felix Heymann
- Department of Hepatology and Gastroenterology, Charité Universitätsmedizin Berlin, Campus Virchow Klinikum and Campus Charité Mitte, Berlin, Germany
| | - Ysbrand Nusse
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
- Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Fernanda V S Castanheira
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
- Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Raymond Shim
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
- Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Adrien Guillot
- Department of Hepatology and Gastroenterology, Charité Universitätsmedizin Berlin, Campus Virchow Klinikum and Campus Charité Mitte, Berlin, Germany
| | - Alix Bruneau
- Department of Hepatology and Gastroenterology, Charité Universitätsmedizin Berlin, Campus Virchow Klinikum and Campus Charité Mitte, Berlin, Germany
| | - Jawairia Atif
- Ajmera Transplant Centre, Toronto General Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Catia Perciani
- Ajmera Transplant Centre, Toronto General Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Christina Ohland
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
- Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | | | - Annika Niehrs
- Leibniz Institute of Virology (LIV), Hamburg, Germany
| | | | | | - Mathias Amrein
- Department of Cell Biology and Anatomy, University of Calgary, Calgary, Alberta, Canada
| | - Zhaoyuan Liu
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Paul M K Gordon
- Centre for Health Genomics and Informatics, University of Calgary, Calgary, Alberta, Canada
| | - Kathy McCoy
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
- Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Department of Microbiology, Immunology and Infectious Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Justin Deniset
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
- Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Department of Cardiac Sciences, University of Calgary, Calgary, Alberta, Canada
- Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Sonya MacParland
- Ajmera Transplant Centre, Toronto General Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Florent Ginhoux
- Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
- Gustave Roussy Cancer Campus, INSERM U1015, Villejuif, France
| | - Frank Tacke
- Department of Hepatology and Gastroenterology, Charité Universitätsmedizin Berlin, Campus Virchow Klinikum and Campus Charité Mitte, Berlin, Germany
| | - Paul Kubes
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
- Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
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6
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Tvilum A, Johansen MI, Glud LN, Ivarsen DM, Khamas AB, Carmali S, Mhatre SS, Søgaard AB, Faddy E, de Vor L, Rooijakkers SHM, Østergaard L, Jørgensen NP, Meyer RL, Zelikin AN. Antibody-Drug Conjugates to Treat Bacterial Biofilms via Targeting and Extracellular Drug Release. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2301340. [PMID: 37290045 PMCID: PMC10427384 DOI: 10.1002/advs.202301340] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 05/22/2023] [Indexed: 06/10/2023]
Abstract
The treatment of implant-associated bacterial infections and biofilms is an urgent medical need and a grand challenge because biofilms protect bacteria from the immune system and harbor antibiotic-tolerant persister cells. This need is addressed herein through an engineering of antibody-drug conjugates (ADCs) that contain an anti-neoplastic drug mitomycin C, which is also a potent antimicrobial against biofilms. The ADCs designed herein release the conjugated drug without cell entry, via a novel mechanism of drug release which likely involves an interaction of ADC with the thiols on the bacterial cell surface. ADCs targeted toward bacteria are superior by the afforded antimicrobial effects compared to the non-specific counterpart, in suspension and within biofilms, in vitro, and in an implant-associated murine osteomyelitis model in vivo. The results are important in developing ADC for a new area of application with a significant translational potential, and in addressing an urgent medical need of designing a treatment of bacterial biofilms.
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Affiliation(s)
- Anne Tvilum
- Department of Chemistry, Aarhus University, Aarhus C, 8000, Denmark
| | - Mikkel I Johansen
- Department of Clinical Medicine, Aarhus University, Aarhus N, 8200, Denmark
- Department of Infectious Diseases, Aarhus University Hospital, Aarhus N, 8200, Denmark
| | - Laerke N Glud
- Interdisciplinary Nanoscience Centre (iNANO), Aarhus University, Aarhus C, 8000, Denmark
| | - Diana M Ivarsen
- Interdisciplinary Nanoscience Centre (iNANO), Aarhus University, Aarhus C, 8000, Denmark
| | - Amanda B Khamas
- Interdisciplinary Nanoscience Centre (iNANO), Aarhus University, Aarhus C, 8000, Denmark
| | - Sheiliza Carmali
- Department of Chemistry, Aarhus University, Aarhus C, 8000, Denmark
| | - Snehit Satish Mhatre
- Interdisciplinary Nanoscience Centre (iNANO), Aarhus University, Aarhus C, 8000, Denmark
| | - Ane B Søgaard
- Department of Chemistry, Aarhus University, Aarhus C, 8000, Denmark
- Interdisciplinary Nanoscience Centre (iNANO), Aarhus University, Aarhus C, 8000, Denmark
| | - Emma Faddy
- Department of Clinical Medicine, Aarhus University, Aarhus N, 8200, Denmark
| | - Lisanne de Vor
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Suzan H M Rooijakkers
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Lars Østergaard
- Department of Clinical Medicine, Aarhus University, Aarhus N, 8200, Denmark
- Department of Infectious Diseases, Aarhus University Hospital, Aarhus N, 8200, Denmark
| | - Nis P Jørgensen
- Department of Infectious Diseases, Aarhus University Hospital, Aarhus N, 8200, Denmark
| | - Rikke L Meyer
- Interdisciplinary Nanoscience Centre (iNANO), Aarhus University, Aarhus C, 8000, Denmark
- Department of Biology, Aarhus University, Aarhus C, 8000, Denmark
| | - Alexander N Zelikin
- Department of Chemistry, Aarhus University, Aarhus C, 8000, Denmark
- Interdisciplinary Nanoscience Centre (iNANO), Aarhus University, Aarhus C, 8000, Denmark
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7
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Wu Y, Chen T, Wang Y, Huang M, Wang Y, Luo Z. New insight into the virulence and inflammatory response of Staphylococcus aureus strains isolated from diabetic foot ulcers. Front Cell Infect Microbiol 2023; 13:1234994. [PMID: 37577369 PMCID: PMC10416727 DOI: 10.3389/fcimb.2023.1234994] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 07/14/2023] [Indexed: 08/15/2023] Open
Abstract
Staphylococcus aureus strains isolated from diabetic foot ulcers (DFUs) have less virulence, but still cause severe infections. Furthermore, hypovirulent S. aureus strains appear to be localized in the deep tissues of diabetic foot osteomyelitis, indicating that the unique environment within DFUs affects the pathogenicity of S. aureus. In this study, the cell-free culture medium (CFCM) of S. aureus strains isolated from DFUs exhibited higher cytotoxicity to human erythrocytes than those isolated from non-diabetic patients with sepsis or wounds. Among these S. aureus strains isolated from DFUs, β-toxin negative strains have less virulence than β-toxin positive strains, but induced a higher expression of inflammatory cytokines. Our study and previous studies have shown that the synergistic effect of phenol-soluble modulin α and β-toxin contributes to the higher hemolytic activity of β-toxin positive strains. However, lysis of human erythrocytes by the CFCM of β-toxin negative strains was greatly inhibited by an autolysin inhibitor, sodium polyanethole sulfonate (SPS). A high level of glucose greatly reduced the hemolytic activity of S. aureus, but promoted the expression of interleukin-6 (IL-6) in human neutrophils. However, 5 mM glucose or glucose-6-phosphate (G6P) increased the hemolytic activity of SA118 (a β-toxin negative strain) isolated from DFUs. Additionally, patients with DFUs with growth of S. aureus had lower level of serum IL-6 than those with other bacteria, and the CFCM of S. aureus strains significantly reduced lipopolysaccharide-induced IL-6 expression in human neutrophils. Therefore, the virulence and inflammatory response of S. aureus strains isolated from DFUs are determined by the levels of glucose and its metabolites, which may explain why it is the predominant bacteria isolated from DFUs.
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Affiliation(s)
- Yuan Wu
- Department of Laboratory Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Ti Chen
- Department of Laboratory Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Yanle Wang
- Department of Laboratory Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Mao Huang
- Department of Laboratory Medicine, Xiangya School of Medicine, Central South University, Changsha, China
| | - Yurong Wang
- Department of Laboratory Medicine, Xiangya School of Medicine, Central South University, Changsha, China
| | - Zhen Luo
- Department of Laboratory Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
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8
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Wang X, Uppu DS, Dickey SW, Burgin DJ, Otto M, Lee JC. Staphylococcus aureus Delta Toxin Modulates both Extracellular Membrane Vesicle Biogenesis and Amyloid Formation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.23.533957. [PMID: 36993475 PMCID: PMC10055364 DOI: 10.1101/2023.03.23.533957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Staphylococcus aureus secretes phenol-soluble modulins (PSMs), a family of small, amphipathic, secreted peptides with multiple biologic activities. Community-acquired S. aureus strains produce high levels of PSMs in planktonic cultures, and PSM alpha peptides have been shown to augment the release of extracellular membrane vesicles (MVs). We observed that amyloids, aggregates of proteins characterized by a fibrillar morphology and stained with specific dyes, co-purified with MVs harvested from cell-free culture supernatants of community-acquired S. aureus strains. δ-toxin was a major component of amyloid fibrils that co-purified with strain LAC MVs, and δ-toxin promoted the production of MVs and amyloid fibrils in a dose-dependent manner. To determine whether MVs and amyloid fibrils were generated under in vivo conditions, we inoculated mice with S. aureus harvested from planktonic cultures. Bacterial MVs could be isolated and purified from lavage fluids recovered from infected animals. Although δ-toxin was the most abundant PSM in lavage fluids, amyloid fibrils could not be detected in these samples. Our findings expand our understanding of amyloid fibril formation in S. aureus cultures, reveal important roles of δ-toxin in amyloid fibril formation and MV biogenesis, and demonstrate that MVs are generated in vivo in a staphylococcal infection model. Importance Extracellular membrane vesicles (MVs) produced by Staphylococcus aureus in planktonic cultures encapsulate a diverse cargo of bacterial proteins, nucleic acids, and glycopolymers that are protected from destruction by external factors. δ-toxin, a member of the phenol soluble modulin family, was shown to be critical for MV biogenesis. Amyloid fibrils co-purified with MVs generated by virulent, community-acquired S. aureus strains, and fibril formation was dependent on expression of the S. aureus δ-toxin gene ( hld ). Mass spectrometry data confirmed that the amyloid fibrils were comprised of δ-toxin. Although S. aureus MVs were produced in vivo in a localized murine infection model, amyloid fibrils were not observed in the in vivo setting. Our findings provide critical insights into staphylococcal factors involved in MV biogenesis and amyloid formation.
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9
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The Small RNA Teg41 Is a Pleiotropic Regulator of Virulence in Staphylococcus aureus. Infect Immun 2022; 90:e0023622. [PMID: 36214557 PMCID: PMC9670889 DOI: 10.1128/iai.00236-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Previously, our group demonstrated a role for the small RNA (sRNA) Teg41 in regulating production of the alpha phenol-soluble modulin toxins (αPSMs) in Staphylococcus aureus. Overexpressing Teg41 increased αPSM production while deleting the 3' end of Teg41 (Teg41Δ3' strain) resulted in a decrease in αPSM production, reduced hemolytic activity of S. aureus culture supernatants, and attenuated virulence in a murine abscess model of infection. In this study, we further explore the attenuation of virulence in the Teg41Δ3' strain. Using both localized and systemic models of infection, we demonstrate that the Teg41Δ3' strain is more severely attenuated than an ΔαPSM mutant, strongly suggesting that Teg41 influences more than the αPSMs. Proteomic and transcriptomic analysis of the wild-type and Teg41Δ3' strains reveals widespread alterations in transcript abundance and protein production in the absence of Teg41, confirming that Teg41 has pleiotropic effects in the cell. We go on to investigate the molecular mechanism underlying Teg41-mediated gene regulation. Surprisingly, results demonstrate that certain Teg41 target genes, including the αPSMs and βPSMs, are transcriptionally altered in the Teg41Δ3' strain, while other targets, specifically spa (encoding surface protein A), are regulated at the level of transcript stability. Collectively, these data demonstrate that Teg41 is a pleiotropic RNA regulator in S. aureus that influences expression of a variety of genes using multiple different mechanisms.
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10
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Role of RNAIII in Resistance to Antibiotics and Antimicrobial Agents in Staphylococcus epidermidis Biofilms. Int J Mol Sci 2022; 23:ijms231911094. [PMID: 36232391 PMCID: PMC9569910 DOI: 10.3390/ijms231911094] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 08/29/2022] [Accepted: 09/16/2022] [Indexed: 11/17/2022] Open
Abstract
Staphylococcus epidermidis is a known opportunistic pathogen and is one of the leading causes of chronic biofilm-associated infections. Biofilm formation is considered as a main strategy to resist antibiotic treatment and help bacteria escape from the human immune system. Understanding the complex mechanisms in biofilm formation can help find new ways to treat resistant strains and lower the prevalence of nosocomial infections. In order to examine the role of RNAIII regulated by the agr quorum sensing system and to what extent it influences biofilm resistance to antimicrobial agents, deletion mutant S. epidermidis RP62a-ΔRNAIII deficient in repressor domains with a re-maining functional hld gene was created. A deletion strain was used to examine the influence of oxacillin in combination with vanillin on biofilm resistance and cell survival was determined. Utilizing real-time qPCR, confocal laser scanning microscopy (CLSM), and crystal violet staining analyses, we found that the RNAIII-independent controlled phenol soluble modulins (PSMs) and RNAIII effector molecule have a significant role in biofilm resistance to antibiotics and phenolic compounds, and it protects the integrity of biofilms. Moreover, a combination of antibiotic and antimicrobial agents can induce methicillin-resistant S. epidermidis biofilm formation and can lead to exceedingly difficult medical treatment.
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11
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Hommes JW, Surewaard BGJ. Intracellular Habitation of Staphylococcus aureus: Molecular Mechanisms and Prospects for Antimicrobial Therapy. Biomedicines 2022; 10:1804. [PMID: 36009351 PMCID: PMC9405036 DOI: 10.3390/biomedicines10081804] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Revised: 07/20/2022] [Accepted: 07/22/2022] [Indexed: 12/23/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) infections pose a global health threat, especially with the continuous development of antibiotic resistance. As an opportunistic pathogen, MRSA infections have a high mortality rate worldwide. Although classically described as an extracellular pathogen, many studies have shown over the past decades that MRSA also has an intracellular aspect to its infectious cycle, which has been observed in vitro in both non-professional as well as professional phagocytes. In vivo, MRSA has been shown to establish an intracellular niche in liver Kupffer cells upon bloodstream infection. The staphylococci have evolved various evasion strategies to survive the antimicrobial environment of phagolysosomes and use these compartments to hide from immune cells and antibiotics. Ultimately, the host cells get overwhelmed by replicating bacteria, leading to cell lysis and bacterial dissemination. In this review, we describe the different intracellular aspects of MRSA infection and briefly mention S. aureus evasion strategies. We discuss how this intracellular niche of bacteria may assist in antibiotic tolerance development, and lastly, we describe various new antibacterial strategies that target the intracellular bacterial niche.
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Affiliation(s)
| | - Bas G. J. Surewaard
- Department of Microbiology, Immunology and Infectious Diseases, Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada;
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12
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Li QQ, Chae HS, Kang OH, Kwon DY. Synergistic Antibacterial Activity with Conventional Antibiotics and Mechanism of Action of Shikonin against Methicillin-Resistant Staphylococcus aureus. Int J Mol Sci 2022; 23:ijms23147551. [PMID: 35886892 PMCID: PMC9322759 DOI: 10.3390/ijms23147551] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Revised: 07/01/2022] [Accepted: 07/06/2022] [Indexed: 12/11/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is a troublesome pathogen that poses a global threat to public health. Shikonin (SKN) isolated from Lithospermum erythrorhizon (L. erythrorhizon) possesses a variety of biological activities. This study aims to explore the effect of the combined application of SKN and traditional antibiotics on the vitality of MRSA and the inherent antibacterial mechanism of SKN. The synergies between SKN and antibiotics against MRSA and its clinical strain have been demonstrated by the checkerboard assay and the time-kill assay. The effect of SKN on disrupting the integrity and permeability of bacterial cell membranes was verified by a nucleotide and protein leakage assay and a bacteriolysis assay. As determined by crystal violet staining, SKN inhibited the biofilm formation of clinical MRSA strains. The results of Western blot and qRT-PCR showed that SKN could inhibit the expression of proteins and genes related to drug resistance and S. aureus exotoxins. SKN inhibited the ability of RAW264.7 cells to release the pro-inflammatory cytokines TNF-α and IL-6, as measured by ELISA. Our findings suggest that SKN has the potential to be developed as a promising alternative for the treatment of MRSA infections.
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Affiliation(s)
- Qian-Qian Li
- Department of Oriental Pharmacy, College of Pharmacy and Wonkwang Oriental Medicines Research Institute, Wonkwang University, Iksan 54538, Jeonbuk, Korea;
| | - Hee-Sung Chae
- National Center for Natural Products Research, School of Pharmacy, The University of Mississippi, Oxford, MS 38677, USA;
| | - Ok-Hwa Kang
- Department of Oriental Pharmacy, College of Pharmacy and Wonkwang Oriental Medicines Research Institute, Wonkwang University, Iksan 54538, Jeonbuk, Korea;
- Correspondence: (O.-H.K.); (D.-Y.K.); Tel.: +82-63-850-6802 (O.-H.K.)
| | - Dong-Yeul Kwon
- Department of Oriental Pharmacy, College of Pharmacy and Wonkwang Oriental Medicines Research Institute, Wonkwang University, Iksan 54538, Jeonbuk, Korea;
- Correspondence: (O.-H.K.); (D.-Y.K.); Tel.: +82-63-850-6802 (O.-H.K.)
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13
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Akbey Ü, Andreasen M. Functional amyloids from bacterial biofilms - structural properties and interaction partners. Chem Sci 2022; 13:6457-6477. [PMID: 35756505 PMCID: PMC9172111 DOI: 10.1039/d2sc00645f] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 05/05/2022] [Indexed: 12/26/2022] Open
Abstract
Protein aggregation and amyloid formation have historically been linked with various diseases such as Alzheimer's and Parkinson's disease, but recently functional amyloids have gained a great deal of interest in not causing a disease and having a distinct function in vivo. Functional bacterial amyloids form the structural scaffold in bacterial biofilms and provide a survival strategy for the bacteria along with antibiotic resistance. The formation of functional amyloids happens extracellularly which differs from most disease related amyloids. Studies of functional amyloids have revealed several distinctions compared to disease related amyloids including primary structures designed to optimize amyloid formation while still retaining a controlled assembly of the individual subunits into classical cross-β-sheet structures, along with a unique cross-α-sheet amyloid fold. Studies have revealed that functional amyloids interact with components found in the extracellular matrix space such as lipids from membranes and polymers from the biofilm. Intriguingly, a level of complexity is added as functional amyloids also interact with several disease related amyloids and a causative link has even been established between functional amyloids and neurodegenerative diseases. It is hence becoming increasingly clear that functional amyloids are not inert protein structures found in bacterial biofilms but interact with many different components including human proteins related to pathology. Gaining a clear understanding of the factors governing the interactions will lead to improved strategies to combat biofilm associated infections and the correlated antibiotic resistance. In the current review we summarize the current state of the art knowledge on this exciting and fast growing research field of biofilm forming bacterial functional amyloids, their structural features and interaction partners.
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Affiliation(s)
- Ümit Akbey
- Department of Structural Biology, School of Medicine, University of Pittsburgh Pittsburgh PA 15261 USA
| | - Maria Andreasen
- Department of Biomedicine, Aarhus University Wilhelm Meyers Allé 3 8000 Aarhus Denmark
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14
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Kretschmer D, Breitmeyer R, Gekeler C, Lebtig M, Schlatterer K, Nega M, Stahl M, Stapels D, Rooijakkers S, Peschel A. Staphylococcus aureus Depends on Eap Proteins for Preventing Degradation of Its Phenol-Soluble Modulin Toxins by Neutrophil Serine Proteases. Front Immunol 2021; 12:701093. [PMID: 34552584 PMCID: PMC8451722 DOI: 10.3389/fimmu.2021.701093] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 08/18/2021] [Indexed: 11/13/2022] Open
Abstract
Neutrophil granulocytes act as a first line of defense against pathogenic staphylococci. However, Staphylococcus aureus has a remarkable capacity to survive neutrophil killing, which distinguishes it from the less-pathogenic Staphylococcus epidermidis. Both species release phenol-soluble modulin (PSM) toxins, which activate the neutrophil formyl-peptide receptor 2 (FPR2) to promote neutrophil influx and phagocytosis, and which disrupt neutrophils or their phagosomal membranes at high concentrations. We show here that the neutrophil serine proteases (NSPs) neutrophil elastase, cathepsin G and proteinase 3, which are released into the extracellular space or the phagosome upon neutrophil FPR2 stimulation, effectively degrade PSMs thereby preventing their capacity to activate and destroy neutrophils. Notably, S. aureus, but not S. epidermidis, secretes potent NSP-inhibitory proteins, Eap, EapH1, EapH2, which prevented the degradation of PSMs by NSPs. Accordingly, a S. aureus mutant lacking all three NSP inhibitory proteins was less effective in activating and destroying neutrophils and it survived less well in the presence of neutrophils than the parental strain. We show that Eap proteins promote pathology via PSM-mediated FPR2 activation since murine intraperitoneal infection with the S. aureus parental but not with the NSP inhibitors mutant strain, led to a significantly higher bacterial load in the peritoneum and kidneys of mFpr2-/- compared to wild-type mice. These data demonstrate that NSPs can very effectively detoxify some of the most potent staphylococcal toxins and that the prominent human pathogen S. aureus has developed efficient inhibitors to preserve PSM functions. Preventing PSM degradation during infection represents an important survival strategy to ensure FPR2 activation.
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Affiliation(s)
- Dorothee Kretschmer
- Interfaculty Institute for Microbiology and Infection Medicine Tübingen (IMIT), Infection Biology, University of Tübingen, Tübingen, Germany.,German Center for Infection Research, Partner Site Tübingen, Tübingen, Germany.,Cluster of Excellence EXC2124 "Controlling Microbes to Fight Infections", Tübingen, Germany
| | - Ricarda Breitmeyer
- Interfaculty Institute for Microbiology and Infection Medicine Tübingen (IMIT), Infection Biology, University of Tübingen, Tübingen, Germany.,German Center for Infection Research, Partner Site Tübingen, Tübingen, Germany.,Cluster of Excellence EXC2124 "Controlling Microbes to Fight Infections", Tübingen, Germany
| | - Cordula Gekeler
- Interfaculty Institute for Microbiology and Infection Medicine Tübingen (IMIT), Infection Biology, University of Tübingen, Tübingen, Germany.,German Center for Infection Research, Partner Site Tübingen, Tübingen, Germany.,Cluster of Excellence EXC2124 "Controlling Microbes to Fight Infections", Tübingen, Germany
| | - Marco Lebtig
- Interfaculty Institute for Microbiology and Infection Medicine Tübingen (IMIT), Infection Biology, University of Tübingen, Tübingen, Germany.,German Center for Infection Research, Partner Site Tübingen, Tübingen, Germany.,Cluster of Excellence EXC2124 "Controlling Microbes to Fight Infections", Tübingen, Germany
| | - Katja Schlatterer
- Interfaculty Institute for Microbiology and Infection Medicine Tübingen (IMIT), Infection Biology, University of Tübingen, Tübingen, Germany.,German Center for Infection Research, Partner Site Tübingen, Tübingen, Germany.,Cluster of Excellence EXC2124 "Controlling Microbes to Fight Infections", Tübingen, Germany
| | - Mulugeta Nega
- Cluster of Excellence EXC2124 "Controlling Microbes to Fight Infections", Tübingen, Germany.,Interfaculty Institute for Microbiology and Infection Medicine Tübingen (IMIT), Microbial Genetics, University of Tübingen, Tübingen, Germany
| | - Mark Stahl
- Center for Plant Molecular Biology (ZMBP), University of Tübingen, Tübingen, Germany
| | - Daphne Stapels
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
| | - Suzan Rooijakkers
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
| | - Andreas Peschel
- Interfaculty Institute for Microbiology and Infection Medicine Tübingen (IMIT), Infection Biology, University of Tübingen, Tübingen, Germany.,German Center for Infection Research, Partner Site Tübingen, Tübingen, Germany.,Cluster of Excellence EXC2124 "Controlling Microbes to Fight Infections", Tübingen, Germany
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15
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Krones D, Rühling M, Becker KA, Kunz TC, Sehl C, Paprotka K, Gulbins E, Fraunholz M. Staphylococcus aureus α-Toxin Induces Acid Sphingomyelinase Release From a Human Endothelial Cell Line. Front Microbiol 2021; 12:694489. [PMID: 34394034 PMCID: PMC8358437 DOI: 10.3389/fmicb.2021.694489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 07/05/2021] [Indexed: 11/14/2022] Open
Abstract
Staphylococcus aureus (S. aureus) is well known to express a plethora of toxins of which the pore-forming hemolysin A (α-toxin) is the best-studied cytolysin. Pore-forming toxins (PFT) permeabilize host membranes during infection thereby causing concentration-dependent effects in host cell membranes ranging from disordered ion fluxes to cytolysis. Host cells possess defense mechanisms against PFT attack, resulting in endocytosis of the breached membrane area and delivery of repair vesicles to the insulted plasma membrane as well as a concurrent release of membrane repair enzymes. Since PFTs from several pathogens have been shown to recruit membrane repair components, we here investigated whether staphylococcal α-toxin is able to induce these mechanisms in endothelial cells. We show that S. aureus α-toxin induced increase in cytosolic Ca2+ in endothelial cells, which was accompanied by p38 MAPK phosphorylation. Toxin challenge led to increased endocytosis of an extracellular fluid phase marker as well as increased externalization of LAMP1-positive membranes suggesting that peripheral lysosomes are recruited to the insulted plasma membrane. We further observed that thereby the lysosomal protein acid sphingomyelinase (ASM) was released into the cell culture medium. Thus, our results show that staphylococcal α-toxin triggers mechanisms in endothelial cells, which have been implicated in membrane repair after damage of other cell types by different toxins.
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Affiliation(s)
- David Krones
- Chair of Microbiology, Biocenter, University of Würzburg, Würzburg, Germany
| | - Marcel Rühling
- Chair of Microbiology, Biocenter, University of Würzburg, Würzburg, Germany
| | - Katrin Anne Becker
- Institute of Molecular Biology, University of Duisburg-Essen, University Hospital, Essen, Germany
| | - Tobias C Kunz
- Chair of Microbiology, Biocenter, University of Würzburg, Würzburg, Germany
| | - Carolin Sehl
- Institute of Molecular Biology, University of Duisburg-Essen, University Hospital, Essen, Germany
| | - Kerstin Paprotka
- Chair of Microbiology, Biocenter, University of Würzburg, Würzburg, Germany
| | - Erich Gulbins
- Institute of Molecular Biology, University of Duisburg-Essen, University Hospital, Essen, Germany.,Department of Surgery, College of Medicine, University of Cincinnati, Cincinnati, OH, United States
| | - Martin Fraunholz
- Chair of Microbiology, Biocenter, University of Würzburg, Würzburg, Germany
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16
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Hommes JW, Kratofil RM, Wahlen S, de Haas CJC, Hildebrand RB, Hovingh GK, Otto M, van Eck M, Hoekstra M, Korporaal SJA, Surewaard BGJ. High density lipoproteins mediate in vivo protection against staphylococcal phenol-soluble modulins. Sci Rep 2021; 11:15357. [PMID: 34321507 PMCID: PMC8319287 DOI: 10.1038/s41598-021-94651-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 06/28/2021] [Indexed: 12/30/2022] Open
Abstract
Staphylococcus aureus virulence has been associated with the production of phenol-soluble modulins (PSMs). These PSMs have distinct virulence functions and are known to activate, attract and lyse neutrophils. These PSM-associated biological functions are inhibited by lipoproteins in vitro. We set out to address whether lipoproteins neutralize staphylococcal PSM-associated virulence in experimental animal models. Serum from both LCAT an ABCA1 knockout mice strains which are characterised by near absence of high-density lipoprotein (HDL) levels, was shown to fail to protect against PSM-induced neutrophil activation and lysis in vitro. Importantly, PSM-induced peritonitis in LCAT-/- mice resulted in increased lysis of resident peritoneal macrophages and enhanced neutrophil recruitment into the peritoneal cavity. Notably, LCAT-/- mice were more likely to succumb to staphylococcal bloodstream infections in a PSM-dependent manner. Plasma from homozygous carriers of ABCA1 variants characterized by very low HDL-cholesterol levels, was found to be less protective against PSM-mediated biological functions compared to healthy humans. Therefore, we conclude that lipoproteins present in blood can protect against staphylococcal PSMs, the key virulence factor of community-associated methicillin resistant S. aureus.
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Affiliation(s)
- Josefien W Hommes
- Department of Microbiology, Immunology, and Infectious Disease. Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada
| | - Rachel M Kratofil
- Department of Microbiology, Immunology, and Infectious Disease. Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada
| | - Sigrid Wahlen
- Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands.,Department of Diagnostic Sciences, Laboratory of Experimental Immunology, Ghent University, Ghent, Belgium
| | - Carla J C de Haas
- Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Reeni B Hildebrand
- Division of BioTherapeutics, Leiden Academic Centre for Drug Research, Gorlaeus Laboratories, Leiden, The Netherlands
| | - G Kees Hovingh
- Department of Vascular Medicine, Academic Medical Center, Amsterdam, The Netherlands
| | - Micheal Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Miranda van Eck
- Division of BioTherapeutics, Leiden Academic Centre for Drug Research, Gorlaeus Laboratories, Leiden, The Netherlands
| | - Menno Hoekstra
- Division of BioTherapeutics, Leiden Academic Centre for Drug Research, Gorlaeus Laboratories, Leiden, The Netherlands
| | - Suzanne J A Korporaal
- Division of BioTherapeutics, Leiden Academic Centre for Drug Research, Gorlaeus Laboratories, Leiden, The Netherlands.,Department of Clinical Chemistry and Haematology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Bas G J Surewaard
- Department of Microbiology, Immunology, and Infectious Disease. Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada. .,Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands.
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17
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Vozza EG, Mulcahy ME, McLoughlin RM. Making the Most of the Host; Targeting the Autophagy Pathway Facilitates Staphylococcus aureus Intracellular Survival in Neutrophils. Front Immunol 2021; 12:667387. [PMID: 34220813 PMCID: PMC8242348 DOI: 10.3389/fimmu.2021.667387] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 05/28/2021] [Indexed: 12/21/2022] Open
Abstract
The success of Staphylococcus aureus as a human commensal and an opportunistic pathogen relies on its ability to adapt to several niches within the host. The innate immune response plays a key role in protecting the host against S. aureus infection; however, S. aureus adeptness at evading the innate immune system is indisputably evident. The “Trojan horse” theory has been postulated to describe a mechanism by which S. aureus takes advantage of phagocytes as a survival niche within the host to facilitate dissemination of S. aureus to secondary sites during systemic infection. Several studies have determined that S. aureus can parasitize both professional and non-professional phagocytes by manipulating the host autophagy pathway in order to create an intracellular survival niche. Neutrophils represent a critical cell type in S. aureus infection as demonstrated by the increased risk of infection among patients with congenital neutrophil disorders. However, S. aureus has been repeatedly shown to survive intracellularly within neutrophils with evidence now supporting a pathogenic role of host autophagy. By manipulating this pathway, S. aureus can also alter the apoptotic fate of the neutrophil and potentially skew other important signalling pathways for its own gain. Understanding these critical host-pathogen interactions could lead to the development of new host directed therapeutics for the treatment of S. aureus infection by removing its intracellular niche and restoring host bactericidal functions. This review discusses the current findings surrounding intracellular survival of S. aureus within neutrophils, the pathogenic role autophagy plays in this process and considers the therapeutic potential for targeting this immune evasion mechanism.
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Affiliation(s)
- Emilio G Vozza
- Host-Pathogen Interactions Group, School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland
| | - Michelle E Mulcahy
- Host-Pathogen Interactions Group, School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland
| | - Rachel M McLoughlin
- Host-Pathogen Interactions Group, School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland
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18
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Kang CY, Kang EYC, Lai CC, Lo WC, Chen KJ, Wu WC, Liu L, Hwang YS, Lo FS, Huang YC. Nasal Methicillin-Resistant Staphylococcus aureus Colonization in Patients with Type 1 Diabetes in Taiwan. Microorganisms 2021; 9:microorganisms9061296. [PMID: 34203580 PMCID: PMC8232090 DOI: 10.3390/microorganisms9061296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 06/09/2021] [Accepted: 06/11/2021] [Indexed: 11/24/2022] Open
Abstract
Nasal methicillin-resistant Staphylococcus aureus (MRSA) colonies are an essential reservoir of infection, especially for patients with diabetes. However, data on MRSA colonization in patients with type 1 diabetes are limited. We investigated the epidemiology of MRSA colonization in patients with type 1 diabetes. This prospective cross-sectional study was conducted in a medical center (Chang Gung Memorial Hospital) in Taiwan from 1 July to 31 December 2020. Nasal sampling and MRSA detection were performed. The molecular characteristics of MRSA isolates were tested, and factors associated with MRSA colonization were analyzed. We included 245 patients with type 1 diabetes; nasal MRSA colonization was identified in 13 (5.3%) patients. All isolates belonged to community-associated MRSA genetic strains; the most frequent strain was clonal complex 45 (53.8%), followed by ST59 (30.8%) (a local community strain). MRSA colonization was positively associated with age ≤ 10 years, body mass index < 18 kg/m2, and diabetes duration < 10 years; moreover, it was negatively associated with serum low-density lipoprotein cholesterol ≥ 100 mg/dL. No independent factor was reported. The nasal MRSA colonization rate in type 1 diabetes is approximately 5% in Taiwan. Most of these colonizing strains are community strains, namely clonal complex 45 and ST59.
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Affiliation(s)
- Chun-Ya Kang
- School of Medicine, Medical University of Lublin, 20529 Lublin, Poland;
| | - Eugene Yu-Chuan Kang
- College of Medicine, Chang Gung University, Taoyuan 333, Taiwan; (E.Y.-C.K.); (C.-C.L.); (K.-J.C.); (W.-C.W.); (L.L.); (Y.-S.H.)
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan 333, Taiwan
| | - Chi-Chun Lai
- College of Medicine, Chang Gung University, Taoyuan 333, Taiwan; (E.Y.-C.K.); (C.-C.L.); (K.-J.C.); (W.-C.W.); (L.L.); (Y.-S.H.)
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan 333, Taiwan
- Department of Family Medicine, National Taiwan University Hospital, Taipei 100, Taiwan
| | - Wei-Che Lo
- Department of Ophthalmology, Keelung Chang Gung Memorial Hospital, Keelung 204, Taiwan;
| | - Kun-Jen Chen
- College of Medicine, Chang Gung University, Taoyuan 333, Taiwan; (E.Y.-C.K.); (C.-C.L.); (K.-J.C.); (W.-C.W.); (L.L.); (Y.-S.H.)
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan 333, Taiwan
| | - Wei-Chi Wu
- College of Medicine, Chang Gung University, Taoyuan 333, Taiwan; (E.Y.-C.K.); (C.-C.L.); (K.-J.C.); (W.-C.W.); (L.L.); (Y.-S.H.)
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan 333, Taiwan
| | - Laura Liu
- College of Medicine, Chang Gung University, Taoyuan 333, Taiwan; (E.Y.-C.K.); (C.-C.L.); (K.-J.C.); (W.-C.W.); (L.L.); (Y.-S.H.)
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan 333, Taiwan
| | - Yih-Shiou Hwang
- College of Medicine, Chang Gung University, Taoyuan 333, Taiwan; (E.Y.-C.K.); (C.-C.L.); (K.-J.C.); (W.-C.W.); (L.L.); (Y.-S.H.)
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan 333, Taiwan
| | - Fu-Sung Lo
- College of Medicine, Chang Gung University, Taoyuan 333, Taiwan; (E.Y.-C.K.); (C.-C.L.); (K.-J.C.); (W.-C.W.); (L.L.); (Y.-S.H.)
- Division of Pediatric Endocrinology and Genetics, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan 333, Taiwan
- Correspondence: (F.-S.L.); (Y.-C.H.); Tel.: +886-3-3281200 (F.-S.L. & Y.-C.H.)
| | - Yhu-Chering Huang
- College of Medicine, Chang Gung University, Taoyuan 333, Taiwan; (E.Y.-C.K.); (C.-C.L.); (K.-J.C.); (W.-C.W.); (L.L.); (Y.-S.H.)
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan 333, Taiwan
- Correspondence: (F.-S.L.); (Y.-C.H.); Tel.: +886-3-3281200 (F.-S.L. & Y.-C.H.)
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19
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Matsumoto M, Nakagawa S, Zhang L, Nakamura Y, Villaruz AE, Otto M, Wolz C, Inohara N, Núñez G. Interaction between Staphylococcus Agr virulence and neutrophils regulates pathogen expansion in the skin. Cell Host Microbe 2021; 29:930-940.e4. [PMID: 33852876 PMCID: PMC11024063 DOI: 10.1016/j.chom.2021.03.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 03/01/2021] [Accepted: 03/16/2021] [Indexed: 01/27/2023]
Abstract
Staphylococcus aureus commonly infects the skin, but the host-pathogen interactions controlling bacterial growth remain unclear. S. aureus virulence is regulated by the Agr quorum-sensing system that controls factors including phenol-soluble modulins (PSMs), a group of cytotoxic peptides. We found a differential requirement for Agr and PSMα for pathogen growth in the skin. In neutrophil-deficient mice, S. aureus growth on the epidermis was unaffected, but the pathogen penetrated the dermis through mechanisms that require PSMα. In the dermis, pathogen expansion required Agr in wild-type mice, but not in neutrophil-deficient mice. Agr limited oxidative and non-oxidative killing in neutrophils by inhibiting pathogen late endosome localization and promoting phagosome escape. Unlike Agr, the SaeR/S virulence program was dispensable for growth in the epidermis and promoted dermal pathogen expansion independently of neutrophils. Thus, S. aureus growth and invasion are differentially regulated with Agr limiting intracellular killing within neutrophils to promote pathogen expansion in the dermis and subcutaneous tissue.
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Affiliation(s)
- Masanori Matsumoto
- Department of Pathology and Rogel Cancer Center, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
| | - Seitaro Nakagawa
- Department of Pathology and Rogel Cancer Center, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Lingzhi Zhang
- Department of Pathology and Rogel Cancer Center, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Yuumi Nakamura
- Cutaneous Immunology, Immunology Frontier Research Center, Osaka University, Osaka 565-0871, Japan
| | - Amer E Villaruz
- Pathogen Molecular Genetics Section, Laboratory of Human Bacterial Pathogenesis, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Human Bacterial Pathogenesis, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Christiane Wolz
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Tübingen, 72076, Germany
| | - Naohiro Inohara
- Department of Pathology and Rogel Cancer Center, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Gabriel Núñez
- Department of Pathology and Rogel Cancer Center, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
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20
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Syed S, Nissilä E, Ruhanen H, Fudo S, Gaytán MO, Sihvo SP, Lorey MB, Metso J, Öörni K, King SJ, Oommen OP, Jauhiainen M, Meri S, Käkelä R, Haapasalo K. Streptococcus pneumoniae pneumolysin and neuraminidase A convert high-density lipoproteins into pro-atherogenic particles. iScience 2021; 24:102535. [PMID: 34124613 PMCID: PMC8175417 DOI: 10.1016/j.isci.2021.102535] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 04/19/2021] [Accepted: 05/10/2021] [Indexed: 11/19/2022] Open
Abstract
High-density lipoproteins (HDLs) are a group of different subpopulations of sialylated particles that have an essential role in the reverse cholesterol transport (RCT) pathway. Importantly, changes in the protein and lipid composition of HDLs may lead to the formation of particles with reduced atheroprotective properties. Here, we show that Streptococcus pneumoniae pneumolysin (PLY) and neuraminidase A (NanA) impair HDL function by causing chemical and structural modifications of HDLs. The proteomic, lipidomic, cellular, and biochemical analysis revealed that PLY and NanA induce significant changes in sialic acid, protein, and lipid compositions of HDL. The modified HDL particles have reduced cholesterol acceptor potential from activated macrophages, elevated levels of malondialdehyde adducts, and show significantly increased complement activating capacity. These results suggest that accumulation of these modified HDL particles in the arterial intima may present a trigger for complement activation, inflammatory response, and thereby promote atherogenic disease progression. S. pneumoniae molecules PLY and NanA target human high-density lipoprotein (HDL). These interactions result in major modifications in the HDL proteome and lipidome. Microbially modified HDL activates humoral and cell-mediated innate immune responses. The activated immune response mediates formation of pro-atherogenic epitopes on HDL.
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Affiliation(s)
- Shahan Syed
- Department of Bacteriology and Immunology, University of Helsinki, 00014 Helsinki, Finland
| | - Eija Nissilä
- Department of Bacteriology and Immunology, University of Helsinki, 00014 Helsinki, Finland
| | - Hanna Ruhanen
- Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, 00014 Helsinki, Finland
- Helsinki University Lipidomics Unit (HiLIPID), Helsinki Institute for Life Science (HiLIFE) and Biocenter Finland, Helsinki 00014, Finland
| | - Satoshi Fudo
- Department of Bacteriology and Immunology, University of Helsinki, 00014 Helsinki, Finland
| | - Meztlli O. Gaytán
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH 43205, USA
| | - Sanna P. Sihvo
- Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, 00014 Helsinki, Finland
- Helsinki University Lipidomics Unit (HiLIPID), Helsinki Institute for Life Science (HiLIFE) and Biocenter Finland, Helsinki 00014, Finland
| | | | - Jari Metso
- Minerva Foundation Institute for Medical Research, Biomedicum, 00290 Helsinki, Finland
- Genomics and Biomarkers Unit, National Institute for Health and Welfare, Helsinki, Finland
| | | | - Samantha J. King
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH 43205, USA
- Department of Pediatrics, The Ohio State University, Columbus, OH 43210, USA
| | - Oommen P. Oommen
- Bioengineering and Nanomedicine Lab, Faculty of Medicine and Health Technology and BioMediTech Institute, Tampere University, 33720 Tampere, Finland
| | - Matti Jauhiainen
- Minerva Foundation Institute for Medical Research, Biomedicum, 00290 Helsinki, Finland
- Genomics and Biomarkers Unit, National Institute for Health and Welfare, Helsinki, Finland
| | - Seppo Meri
- Department of Bacteriology and Immunology, University of Helsinki, 00014 Helsinki, Finland
| | - Reijo Käkelä
- Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, 00014 Helsinki, Finland
- Helsinki University Lipidomics Unit (HiLIPID), Helsinki Institute for Life Science (HiLIFE) and Biocenter Finland, Helsinki 00014, Finland
| | - Karita Haapasalo
- Department of Bacteriology and Immunology, University of Helsinki, 00014 Helsinki, Finland
- Corresponding author
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21
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Deppermann C, Peiseler M, Zindel J, Zbytnuik L, Lee WY, Pasini E, Baciu C, Matelski J, Lee Y, Kumar D, Humar A, Surewaard B, Kubes P, Bhat M. Tacrolimus Impairs Kupffer Cell Capacity to Control Bacteremia: Why Transplant Recipients Are Susceptible to Infection. Hepatology 2021; 73:1967-1984. [PMID: 32761929 DOI: 10.1002/hep.31499] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 05/29/2020] [Accepted: 06/28/2020] [Indexed: 12/21/2022]
Abstract
BACKGROUND AND AIMS Kupffer cells (KCs) are the resident intravascular phagocyte population of the liver and critical to the capture and killing of bacteria. Calcineurin/nuclear factor of activated T cells (NFAT) inhibitors (CNIs) such as tacrolimus are used to prevent rejection in solid organ transplant recipients. Although their effect on lymphocytes has been studied extensively, there are limited experimental data about if and how CNIs shape innate immunity, and whether this contributes to the higher rates of infection observed in patients taking CNIs. APPROACH AND RESULTS Here, we investigated the impact of tacrolimus treatment on innate immunity and, more specifically, on the capability of Kupffer cells (KCs) to fight infections. Retrospective analysis of data of >2,700 liver transplant recipients showed that taking calcineurin inhibitors such as tacrolimus significantly increased the likelihood of Staphylococcus aureus infection. Using a mouse model of acute methicillin-resistant S. aureus (MRSA) bacteremia, most bacteria were sequestered in the liver and we found that bacteria were more likely to disseminate and kill the host in tacrolimus-treated mice. Using imaging, we unveiled the mechanism underlying this observation: the reduced capability of KCs to capture, phagocytose, and destroy bacteria in tacrolimus-treated animals. Furthermore, in a gene expression analysis of infected KCs, the triggering receptor expressed on myeloid cells 1 (TREM1) pathway was the one with the most significant down-regulation after tacrolimus treatment. TREM1 inhibition likewise inhibited KC bacteria capture. TREM1 levels on neutrophils as well as the overall neutrophil response after infection were unaffected by tacrolimus treatment. CONCLUSIONS Our results indicate that tacrolimus treatment has a significant impact directly on KCs and on TREM1, thereby compromising their capacity to fend off infections.
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Affiliation(s)
- Carsten Deppermann
- Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AL, Canada.,Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Moritz Peiseler
- Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AL, Canada
| | - Joel Zindel
- Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AL, Canada
| | - Lori Zbytnuik
- Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AL, Canada
| | - Woo-Yong Lee
- Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AL, Canada
| | - Elisa Pasini
- Department of Medicine, Multi-Organ Transplant Program, Toronto General Hospital, Toronto, ON, Canada
| | - Cristina Baciu
- Department of Medicine, Multi-Organ Transplant Program, Toronto General Hospital, Toronto, ON, Canada
| | - John Matelski
- Biostatistics Research Unit, University Health Network, Toronto, ON, Canada
| | - Yun Lee
- Department of Medicine, Multi-Organ Transplant Program, Toronto General Hospital, Toronto, ON, Canada
| | - Deepali Kumar
- Department of Medicine, Multi-Organ Transplant Program, Toronto General Hospital, Toronto, ON, Canada
| | - Atul Humar
- Department of Medicine, Multi-Organ Transplant Program, Toronto General Hospital, Toronto, ON, Canada
| | - Bas Surewaard
- Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AL, Canada
| | - Paul Kubes
- Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AL, Canada
| | - Mamatha Bhat
- Department of Medicine, Multi-Organ Transplant Program, Toronto General Hospital, Toronto, ON, Canada
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22
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Cheung GYC, Bae JS, Liu R, Hunt RL, Zheng Y, Otto M. Bacterial virulence plays a crucial role in MRSA sepsis. PLoS Pathog 2021; 17:e1009369. [PMID: 33630954 PMCID: PMC7942999 DOI: 10.1371/journal.ppat.1009369] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Revised: 03/09/2021] [Accepted: 02/10/2021] [Indexed: 12/29/2022] Open
Abstract
Bacterial sepsis is a major global cause of death. However, the pathophysiology of sepsis has remained poorly understood. In industrialized nations, Staphylococcus aureus represents the pathogen most commonly associated with mortality due to sepsis. Because of the alarming spread of antibiotic resistance, anti-virulence strategies are often proposed to treat staphylococcal sepsis. However, we do not yet completely understand if and how bacterial virulence contributes to sepsis, which is vital for a thorough assessment of such strategies. We here examined the role of virulence and quorum-sensing regulation in mouse and rabbit models of sepsis caused by methicillin-resistant S. aureus (MRSA). We determined that leukopenia was a predictor of disease outcome during an early critical stage of sepsis. Furthermore, in device-associated infection as the most frequent type of staphylococcal blood infection, quorum-sensing deficiency resulted in significantly higher mortality. Our findings give important guidance regarding anti-virulence drug development strategies for the treatment of staphylococcal sepsis. Moreover, they considerably add to our understanding of how bacterial sepsis develops by revealing a critical early stage of infection during which the battle between bacteria and leukocytes determines sepsis outcome. While sepsis has traditionally been attributed mainly to host factors, our study highlights a key role of the invading pathogen and its virulence mechanisms.
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Affiliation(s)
- Gordon Y. C. Cheung
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Justin S. Bae
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Ryan Liu
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Rachelle L. Hunt
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Yue Zheng
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
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23
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Deppermann C, Kratofil RM, Peiseler M, David BA, Zindel J, Castanheira FVES, van der Wal F, Carestia A, Jenne CN, Marth JD, Kubes P. Macrophage galactose lectin is critical for Kupffer cells to clear aged platelets. J Exp Med 2020; 217:133651. [PMID: 31978220 PMCID: PMC7144524 DOI: 10.1084/jem.20190723] [Citation(s) in RCA: 83] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 10/01/2019] [Accepted: 12/17/2019] [Indexed: 12/21/2022] Open
Abstract
Every day, megakaryocytes produce billions of platelets that circulate for several days and eventually are cleared by the liver. The exact removal mechanism, however, remains unclear. Loss of sialic acid residues is thought to feature in the aging and clearance of platelets. Using state-of-the-art spinning disk intravital microscopy to delineate the different compartments and cells of the mouse liver, we observed rapid accumulation of desialylated platelets predominantly on Kupffer cells, with only a few on endothelial cells and none on hepatocytes. Kupffer cell depletion prevented the removal of aged platelets from circulation. Ashwell-Morell receptor (AMR) deficiency alone had little effect on platelet uptake. Macrophage galactose lectin (MGL) together with AMR mediated clearance of desialylated or cold-stored platelets by Kupffer cells. Effective clearance is critical, as mice with an aged platelet population displayed a bleeding phenotype. Our data provide evidence that the MGL of Kupffer cells plays a significant role in the removal of desialylated platelets through a collaboration with the AMR, thereby maintaining a healthy and functional platelet compartment.
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Affiliation(s)
- Carsten Deppermann
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada.,Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, Canada.,Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Rachel M Kratofil
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada.,Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, Canada
| | - Moritz Peiseler
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada.,Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, Canada
| | - Bruna A David
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada.,Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, Canada
| | - Joel Zindel
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada.,Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, Canada
| | - Fernanda Vargas E Silva Castanheira
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada.,Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, Canada
| | - Fardau van der Wal
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada.,Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, Canada
| | - Agostina Carestia
- Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, Canada.,Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
| | - Craig N Jenne
- Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, Canada.,Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
| | - Jamey D Marth
- Center for Nanomedicine, SBP Medical Discovery Institute, and Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA
| | - Paul Kubes
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada.,Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, Canada
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24
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Amin Yavari S, Castenmiller SM, van Strijp JAG, Croes M. Combating Implant Infections: Shifting Focus from Bacteria to Host. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e2002962. [PMID: 32914481 DOI: 10.1002/adma.202002962] [Citation(s) in RCA: 91] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 06/28/2020] [Indexed: 05/06/2023]
Abstract
The widespread use of biomaterials to support or replace body parts is increasingly threatened by the risk of implant-associated infections. In the quest for finding novel anti-infective biomaterials, there generally has been a one-sided focus on biomaterials with direct antibacterial properties, which leads to excessive use of antibacterial agents, compromised host responses, and unpredictable effectiveness in vivo. This review sheds light on how host immunomodulation, rather than only targeting bacteria, can endow biomaterials with improved anti-infective properties. How antibacterial surface treatments are at risk to be undermined by biomaterial features that dysregulate the protection normally provided by critical immune cell subsets, namely, neutrophils and macrophages, is discussed. Accordingly, how the precise modification of biomaterial surface biophysical cues, or the incorporation of immunomodulatory drug delivery systems, can render biomaterials with the necessary immune-compatible and immune-protective properties to potentiate the host defense mechanisms is reviewed. Within this context, the protective role of host defense peptides, metallic particles, quorum sensing inhibitors, and therapeutic adjuvants is discussed. The highlighted immunomodulatory strategies may lay a foundation to develop anti-infective biomaterials, while mitigating the increasing threat of antibacterial drug resistance.
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Affiliation(s)
- Saber Amin Yavari
- Department of Orthopedics, University Medical Center Utrecht, Utrecht, 3508GA, The Netherlands
| | - Suzanne M Castenmiller
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, 3508GA, The Netherlands
| | - Jos A G van Strijp
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, 3508GA, The Netherlands
| | - Michiel Croes
- Department of Orthopedics, University Medical Center Utrecht, Utrecht, 3508GA, The Netherlands
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25
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Bogoslowski A, Wijeyesinghe S, Lee WY, Chen CS, Alanani S, Jenne C, Steeber DA, Scheiermann C, Butcher EC, Masopust D, Kubes P. Neutrophils Recirculate through Lymph Nodes to Survey Tissues for Pathogens. THE JOURNAL OF IMMUNOLOGY 2020; 204:2552-2561. [PMID: 32205425 DOI: 10.4049/jimmunol.2000022] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Accepted: 03/03/2020] [Indexed: 12/22/2022]
Abstract
The adaptive immune function of lymph nodes is dependent on constant recirculation of lymphocytes. In this article, we identify neutrophils present in the lymph node at steady state, exhibiting the same capacity for recirculation. In germ-free mice, neutrophils still recirculate through lymph nodes, and in mice cohoused with wild microbiome mice, the level of neutrophils in lymph nodes increases significantly. We found that at steady state, neutrophils enter the lymph node entirely via L-selectin and actively exit via efferent lymphatics via an S1P dependent mechanism. The small population of neutrophils in the lymph node can act as reconnaissance cells to recruit additional neutrophils in the event of bacterial dissemination to the lymph node. Without these reconnaissance cells, there is a delay in neutrophil recruitment to the lymph node and a reduction in swarm formation following Staphylococcus aureus infection. This ability to recruit additional neutrophils by lymph node neutrophils is initiated by LTB4. This study establishes the capacity of neutrophils to recirculate, much like lymphocytes via L-selectin and high endothelial venules in lymph nodes and demonstrates how the presence of neutrophils at steady state fortifies the lymph node in case of an infection disseminating through lymphatics.
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Affiliation(s)
- Ania Bogoslowski
- Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, University of Calgary, Alberta T2N 4N1, Canada
| | - Sathi Wijeyesinghe
- Department of Microbiology and Immunology, Center for Immunology, University of Minnesota, Minneapolis, MN 55455
| | - Woo-Young Lee
- Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, University of Calgary, Alberta T2N 4N1, Canada
| | - Chien-Sin Chen
- Walter Brendel Centre of Experimental Medicine, University Hospital, Ludwig Maximilians University of Munich, BioMedical Centre, 82152 Planegg-Martinsried, Germany
| | - Samer Alanani
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI 53201
| | - Craig Jenne
- Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, University of Calgary, Alberta T2N 4N1, Canada
| | - Douglas A Steeber
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI 53201
| | - Christoph Scheiermann
- Walter Brendel Centre of Experimental Medicine, University Hospital, Ludwig Maximilians University of Munich, BioMedical Centre, 82152 Planegg-Martinsried, Germany.,University of Geneva, Department of Pathology and Immunology, 1211 Geneva, Switzerland; and
| | - Eugene C Butcher
- Laboratory of Immunology and Vascular Biology, Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305.,The Center for Molecular Biology and Medicine, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304
| | - David Masopust
- Department of Microbiology and Immunology, Center for Immunology, University of Minnesota, Minneapolis, MN 55455
| | - Paul Kubes
- Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, University of Calgary, Alberta T2N 4N1, Canada;
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26
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de Vor L, Rooijakkers SHM, van Strijp JAG. Staphylococci evade the innate immune response by disarming neutrophils and forming biofilms. FEBS Lett 2020; 594:2556-2569. [PMID: 32144756 DOI: 10.1002/1873-3468.13767] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 01/30/2020] [Accepted: 02/22/2020] [Indexed: 12/24/2022]
Abstract
Staphylococcus aureus and Staphylococcus epidermidis can cause many types of infections, ranging from skin infections to implant-associated infections. The primary innate immune response against bacterial infections involves complement activation, recruitment of phagocytes (most importantly neutrophils), and subsequent killing of the pathogen. However, staphylococci are not innocent bystanders; they actively obstruct this immune attack. To do that, S. aureus secretes several immune-evasion proteins to resist attack by the innate immune system. Furthermore, S. aureus and S. epidermidis are known for their ability to form biofilms on implanted medical devices and host tissues, which provides another important immune-evasion mechanism. Understanding these different strategies to resist immune attack will help to develop novel therapies against staphylococcal infections.
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Affiliation(s)
- Lisanne de Vor
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, The Netherlands
| | - Suzan H M Rooijakkers
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, The Netherlands
| | - Jos A G van Strijp
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, The Netherlands
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27
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Abstract
Staphylococcus aureus has become a serious threat to human health. In addition to having increased antibiotic resistance, the bacterium is a master at adapting to its host by evading almost every facet of the immune system, the so-called immune evasion proteins. Many of these immune evasion proteins target neutrophils, the most important immune cells in clearing S. aureus infections. The neutrophil attacks pathogens via a plethora of strategies. Therefore, it is no surprise that S. aureus has evolved numerous immune evasion strategies at almost every level imaginable. In this review we discuss step by step the aspects of neutrophil-mediated killing of S. aureus, such as neutrophil activation, migration to the site of infection, bacterial opsonization, phagocytosis, and subsequent neutrophil-mediated killing. After each section we discuss how S. aureus evasion molecules are able to resist the neutrophil attack of these different steps. To date, around 40 immune evasion molecules of S. aureus are known, but its repertoire is still expanding due to the discovery of new evasion proteins and the addition of new functions to already identified evasion proteins. Interestingly, because the different parts of neutrophil attack are redundant, the evasion molecules display redundant functions as well. Knowing how and with which proteins S. aureus is evading the immune system is important in understanding the pathophysiology of this pathogen. This knowledge is crucial for the development of therapeutic approaches that aim to clear staphylococcal infections.
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28
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A FASII Inhibitor Prevents Staphylococcal Evasion of Daptomycin by Inhibiting Phospholipid Decoy Production. Antimicrob Agents Chemother 2019; 63:AAC.02105-18. [PMID: 30718253 PMCID: PMC6496159 DOI: 10.1128/aac.02105-18] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 01/29/2019] [Indexed: 12/14/2022] Open
Abstract
Daptomycin is a treatment of last resort for serious infections caused by drug-resistant Gram-positive pathogens, such as methicillin-resistant Staphylococcus aureus. We have shown recently that S. aureus can evade daptomycin by releasing phospholipid decoys that sequester and inactivate the antibiotic, leading to treatment failure. Daptomycin is a treatment of last resort for serious infections caused by drug-resistant Gram-positive pathogens, such as methicillin-resistant Staphylococcus aureus. We have shown recently that S. aureus can evade daptomycin by releasing phospholipid decoys that sequester and inactivate the antibiotic, leading to treatment failure. Since phospholipid release occurs via an active process, we hypothesized that it could be inhibited, thereby increasing daptomycin efficacy. To identify opportunities for therapeutic interventions that block phospholipid release, we first determined how the host environment influences the release of phospholipids and the inactivation of daptomycin by S. aureus. The addition of certain host-associated fatty acids to the growth medium enhanced phospholipid release. However, in serum, the sequestration of fatty acids by albumin restricted their availability to S. aureus sufficiently to prevent their use in the generation of released phospholipids. This finding implies that in host tissues S. aureus may be completely dependent upon endogenous phospholipid biosynthesis to generate lipids for release, providing a target for therapeutic intervention. To test this, we exposed S. aureus to AFN-1252, an inhibitor of the staphylococcal FASII fatty acid biosynthetic pathway, together with daptomycin. AFN-1252 efficiently blocked daptomycin-induced phospholipid decoy production, even in the case of isolates resistant to AFN-1252, which prevented the inactivation of daptomycin and resulted in sustained bacterial killing. In turn, daptomycin prevented the fatty acid-dependent emergence of AFN-1252-resistant isolates in vitro. In summary, AFN-1252 significantly enhances daptomycin activity against S. aureusin vitro by blocking the production of phospholipid decoys, while daptomycin blocks the emergence of resistance to AFN-1252.
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29
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Pang M, Zhu M, Lei X, Xu P, Cheng B. Microbiome Imbalances: An Overlooked Potential Mechanism in Chronic Nonhealing Wounds. INT J LOW EXTR WOUND 2019; 18:31-41. [PMID: 30836811 DOI: 10.1177/1534734619832754] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Chronic nonhealing wounds are a severe burden to health care systems worldwide, causing millions of patients to have lengthy hospital stays, high health care costs, periods of unemployment, and reduced quality of life. Moreover, treating chronic nonhealing wounds effectively and reasonably in countries with limited medical resources can be extremely challenging. With many outstanding questions surrounding chronic nonhealing wounds, in this review, we offer changes to the microbiome as a potentially ignored mechanism important in the formation and treatment of chronic wounds. Our analysis helps bring a whole new understanding to wound formation and healing and provides a potential breakthrough in the treatment of chronic nonhealing wounds in the future.
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Affiliation(s)
- Mengru Pang
- The Graduate School of Southern Medical University, Guangzhou, China
- General Hospital of Southern Theater Command, PLA, Guangzhou, China
| | - Meishu Zhu
- The Graduate School of Southern Medical University, Guangzhou, China
- The First Affiliated Hospital of Shenzhen University, Shenzhen, China
| | - Xiaoxuan Lei
- The Graduate School of Southern Medical University, Guangzhou, China
- General Hospital of Southern Theater Command, PLA, Guangzhou, China
| | - Pengcheng Xu
- General Hospital of Southern Theater Command, PLA, Guangzhou, China
| | - Biao Cheng
- The Graduate School of Southern Medical University, Guangzhou, China
- General Hospital of Southern Theater Command, PLA, Guangzhou, China
- The Key Laboratory of Trauma Treatment and Tissue Repair of Tropical Area, PLA, Guangzhou, China
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30
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Tam K, Torres VJ. Staphylococcus aureus Secreted Toxins and Extracellular Enzymes. Microbiol Spectr 2019; 7:10.1128/microbiolspec.GPP3-0039-2018. [PMID: 30873936 PMCID: PMC6422052 DOI: 10.1128/microbiolspec.gpp3-0039-2018] [Citation(s) in RCA: 197] [Impact Index Per Article: 39.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Indexed: 02/06/2023] Open
Abstract
Staphylococcus aureus is a formidable pathogen capable of causing infections in different sites of the body in a variety of vertebrate animals, including humans and livestock. A major contribution to the success of S. aureus as a pathogen is the plethora of virulence factors that manipulate the host's innate and adaptive immune responses. Many of these immune modulating virulence factors are secreted toxins, cofactors for activating host zymogens, and exoenzymes. Secreted toxins such as pore-forming toxins and superantigens are highly inflammatory and can cause leukocyte cell death by cytolysis and clonal deletion, respectively. Coagulases and staphylokinases are cofactors that hijack the host's coagulation system. Exoenzymes, including nucleases and proteases, cleave and inactivate various immune defense and surveillance molecules, such as complement factors, antimicrobial peptides, and surface receptors that are important for leukocyte chemotaxis. Additionally, some of these secreted toxins and exoenzymes can cause disruption of endothelial and epithelial barriers through cell lysis and cleavage of junction proteins. A unique feature when examining the repertoire of S. aureus secreted virulence factors is the apparent functional redundancy exhibited by the majority of the toxins and exoenzymes. However, closer examination of each virulence factor revealed that each has unique properties that have important functional consequences. This chapter provides a brief overview of our current understanding of the major secreted virulence factors critical for S. aureus pathogenesis.
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Affiliation(s)
- Kayan Tam
- Department of Microbiology, New York University School of Medicine, Alexandria Center for Life Science, New York, NY 10016
| | - Victor J Torres
- Department of Microbiology, New York University School of Medicine, Alexandria Center for Life Science, New York, NY 10016
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Wu X, Yang M, Fang X, Zhen S, Zhang J, Yang X, Qiao L, Yang Y, Zhang C. Expression and regulation of phenol-soluble modulins and enterotoxins in foodborne Staphylococcus aureus. AMB Express 2018; 8:187. [PMID: 30467730 PMCID: PMC6250609 DOI: 10.1186/s13568-018-0717-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 11/17/2018] [Indexed: 12/15/2022] Open
Abstract
Although high levels of staphylococcal phenol-soluble modulins (PSMs) in clinical methicillin-resistant Staphylococcus aureus (MRSA) has been shown to correlate with bacterial virulence, the PSMs expression in foodborne Staphylococcus aureus (S. aureus), as well as its association with staphylococcal food poisoning (SFP) was not yet clear. We collected a panel of 350 foodborne and 127 clinic-derived S. aureus strains and compared their PSMs expression. Overall, foodborne strains exhibited higher PSMs than clinical isolates, indicating a potential pathological significance of PSMs in staphylococcal food contamination. Furthermore, PSMs expression and staphylococcal enterotoxins (SEs) levels in relation to antibiotic sensitive and resistant strains were analysed. While the co-expression of PSMs and SEs was confirmed, one typical foodborne strain simultaneously yielding PSMs, SEB and SED was selected. By comparing this wildtype strain to a series of gene-deficient mutants, we concluded that PSMs and SEs expressions both relied on staphylococcal accessory regulator A initiation in the early stage of accessory gene regulator control, yet their succedent regulations differentiated to RNAIII-dependent and independent, respectively. These data provided preliminary insight into PSMs and SEs expression in foodborne S. aureus, and may guide the further studies on PSMs effects in SFP.
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Zhao Y, van Kessel KPM, de Haas CJC, Rogers MRC, van Strijp JAG, Haas PA. Staphylococcal superantigen-like protein 13 activates neutrophils via formyl peptide receptor 2. Cell Microbiol 2018; 20:e12941. [PMID: 30098280 PMCID: PMC6220968 DOI: 10.1111/cmi.12941] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 07/06/2018] [Accepted: 07/18/2018] [Indexed: 12/19/2022]
Abstract
Staphylococcal superantigen-like (SSL) proteins, one of the major virulence factor families produced by Staphylococcus aureus, were previously demonstrated to be immune evasion molecules that interfere with a variety of innate immune defences. However, in contrast to characterised SSLs, which inhibit immune functions, we show that SSL13 is a strong activator of neutrophils via the formyl peptide receptor 2 (FPR2). Moreover, our data show that SSL13 acts as a chemoattractant and induces degranulation and oxidative burst in neutrophils. As with many other staphylococcal immune evasion proteins, SSL13 shows a high degree of human specificity. SSL13 is not able to efficiently activate mouse neutrophils, hampering in vivo experiments. In conclusion, SSL13 is a neutrophil chemoattractant and activator that acts via FPR2. Therefore, SSL13 is a unique SSL member that does not belong to the immune evasion class but is a pathogen alarming molecule. Our study provides a new concept of SSLs; SSLs not only inhibit host immune processes but also recruit human neutrophils to the site of infection. This new insight allows us to better understand complex interactions between host and S. aureus pathological processes.
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Affiliation(s)
- Yuxi Zhao
- Department of Medical MicrobiologyUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Kok P. M. van Kessel
- Department of Medical MicrobiologyUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Carla J. C. de Haas
- Department of Medical MicrobiologyUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Malbert R. C. Rogers
- Department of Medical MicrobiologyUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Jos A. G. van Strijp
- Department of Medical MicrobiologyUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Pieter‐Jan A. Haas
- Department of Medical MicrobiologyUniversity Medical Center UtrechtUtrechtThe Netherlands
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Human skin commensals augment Staphylococcus aureus pathogenesis. Nat Microbiol 2018; 3:881-890. [PMID: 30013237 PMCID: PMC6207346 DOI: 10.1038/s41564-018-0198-3] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Accepted: 06/15/2018] [Indexed: 02/07/2023]
Abstract
All bacterial infections occur within a polymicrobial environment, from which a pathogen population emerges to establish disease within a host. Emphasis has been placed on prevention of pathogen dominance by competing microflora acting as probiotics1. Here we show that virulence of the human pathogen, Staphylococcus aureus is augmented by native, polymicrobial, commensal skin flora and individual species acting as “proinfectious agents”. The outcome is pathogen proliferation but not commensal. Pathogenesis augmentation can be mediated by particulate cell wall peptidoglycan (PGN), reducing the S. aureus infectious dose by over 1000-fold. This phenomenon occurs using a range of S. aureus strains, infection models and is not mediated by established receptor-mediated pathways including Nod1, Nod2, Myd88 and the NLPR3 inflammasome. During mouse sepsis, augmentation depends on liver resident macrophages (Kupffer cells, KC), that capture and internalise both pathogen and ‘proinfectious agent’, leading to reduced production of reactive oxygen species, pathogen survival and subsequent multiple liver abscess formation. The augmented infection model more closely resembles the natural situation and establishes the role of resident environmental microflora in initiation of disease by an invading pathogen. As human microflora is ubiquitous2 its role in increasing susceptibility to infection S. aureus highlights potential strategies for disease prevention.
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Zhang X, Marichannegowda MH, Rakesh KP, Qin HL. Master mechanisms of Staphylococcus aureus: consider its excellent protective mechanisms hindering vaccine development! Microbiol Res 2018; 212-213:59-66. [DOI: 10.1016/j.micres.2018.05.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 04/26/2018] [Accepted: 05/02/2018] [Indexed: 12/30/2022]
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Maali Y, Badiou C, Martins-Simões P, Hodille E, Bes M, Vandenesch F, Lina G, Diot A, Laurent F, Trouillet-Assant S. Understanding the Virulence of Staphylococcus pseudintermedius: A Major Role of Pore-Forming Toxins. Front Cell Infect Microbiol 2018; 8:221. [PMID: 30003063 PMCID: PMC6032551 DOI: 10.3389/fcimb.2018.00221] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 06/11/2018] [Indexed: 11/22/2022] Open
Abstract
Staphylococcus pseudintermedius is responsible for severe and necrotizing infections in humans and dogs. Contrary to S. aureus, the pathophysiological mechanisms involved in this virulence are incompletely understood. We previously showed the intracellular cytotoxicity induced after internalization of S. pseudintermedius. Herein, we aimed to identify the virulence factors responsible for this cytotoxic activity. After addition of filtered S. pseudintermedius supernatants in culture cell media, MG63 cells, used as representative of non-professional phagocytic cells (NPPc), released a high level of LDH, indicating that the cytotoxicity was mainly mediated by secreted factors. Accordingly, we focused our attention on S. pseudintermedius toxins. In silico analysis found the presence of two PSMs (δ-toxin and PSMε) as well as Luk-I leukotoxin, the presence of which was confirmed by PCR in all clinical strains tested (n = 17). Recombinant Luk-I leukotoxin had no cytotoxic activity on NPPc but the ectopic expression of the CXCR2 receptor in U937 cells conferred cytotoxity to Luk-I. This is in agreement with the lack of Luk-I effect on NPPc and the previous report of Luk-I cytoxic activity on immune cells. Contrary to Luk-I, synthetic δ-toxin and PSMε had a strong cytotoxic activity on NPPc. The secretion of δ-toxin and PSMε at cytotoxic concentrations by S. pseudintermedius in culture supernatant was confirmed by HPLC-MS. In addition, the supplementation of such supernatants with human serum, known to inhibit PSM, induced a complete abolition of cytotoxicity which indicates that PSMs are the key players in the cytotoxic phenotype of NPPc. The results suggest that the severity of S. pseudintermedius infections is, at least in part, explained by a combined action of Luk-I that specifically targets immune cells expressing the CXCR2 receptor, and PSMs that disrupt cell membranes whatever the cell types. The present study strengthens the key role of PSMs in virulence of the different species belonging to Staphylococcus genus.
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Affiliation(s)
- Yousef Maali
- Centre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale, U1111, Centre National de la Recherche Scientifique, UMR5308, Université de Lyon 1, École Normale Supérieure de Lyon, Team "Pathogenesis of Staphylococcal Infections", Lyon, France
| | - Cédric Badiou
- Centre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale, U1111, Centre National de la Recherche Scientifique, UMR5308, Université de Lyon 1, École Normale Supérieure de Lyon, Team "Pathogenesis of Staphylococcal Infections", Lyon, France
| | - Patrícia Martins-Simões
- Centre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale, U1111, Centre National de la Recherche Scientifique, UMR5308, Université de Lyon 1, École Normale Supérieure de Lyon, Team "Pathogenesis of Staphylococcal Infections", Lyon, France.,Institut des Agents Infectieux, Hospices Civils de Lyon, Lyon, France.,Centre National de Référence des Staphylocoques, Hospices Civils de Lyon, Lyon, France
| | - Elisabeth Hodille
- Centre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale, U1111, Centre National de la Recherche Scientifique, UMR5308, Université de Lyon 1, École Normale Supérieure de Lyon, Team "Pathogenesis of Staphylococcal Infections", Lyon, France.,Institut des Agents Infectieux, Hospices Civils de Lyon, Lyon, France
| | - Michele Bes
- Institut des Agents Infectieux, Hospices Civils de Lyon, Lyon, France.,Centre National de Référence des Staphylocoques, Hospices Civils de Lyon, Lyon, France
| | - François Vandenesch
- Centre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale, U1111, Centre National de la Recherche Scientifique, UMR5308, Université de Lyon 1, École Normale Supérieure de Lyon, Team "Pathogenesis of Staphylococcal Infections", Lyon, France.,Institut des Agents Infectieux, Hospices Civils de Lyon, Lyon, France.,Centre National de Référence des Staphylocoques, Hospices Civils de Lyon, Lyon, France
| | - Gérard Lina
- Centre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale, U1111, Centre National de la Recherche Scientifique, UMR5308, Université de Lyon 1, École Normale Supérieure de Lyon, Team "Pathogenesis of Staphylococcal Infections", Lyon, France.,Institut des Agents Infectieux, Hospices Civils de Lyon, Lyon, France.,Centre National de Référence des Staphylocoques, Hospices Civils de Lyon, Lyon, France
| | - Alan Diot
- Centre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale, U1111, Centre National de la Recherche Scientifique, UMR5308, Université de Lyon 1, École Normale Supérieure de Lyon, Team "Pathogenesis of Staphylococcal Infections", Lyon, France
| | - Frederic Laurent
- Centre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale, U1111, Centre National de la Recherche Scientifique, UMR5308, Université de Lyon 1, École Normale Supérieure de Lyon, Team "Pathogenesis of Staphylococcal Infections", Lyon, France.,Institut des Agents Infectieux, Hospices Civils de Lyon, Lyon, France.,Centre National de Référence des Staphylocoques, Hospices Civils de Lyon, Lyon, France
| | - Sophie Trouillet-Assant
- Centre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale, U1111, Centre National de la Recherche Scientifique, UMR5308, Université de Lyon 1, École Normale Supérieure de Lyon, Team "Pathogenesis of Staphylococcal Infections", Lyon, France.,Institut des Agents Infectieux, Hospices Civils de Lyon, Lyon, France.,Laboratoire Commun de Recherche Lyon Sud, Hospices Civils de Lyon-bioMérieux, Pierre Bénite, France
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Wolfmeier H, Mansour SC, Liu LT, Pletzer D, Draeger A, Babiychuk EB, Hancock REW. Liposomal Therapy Attenuates Dermonecrosis Induced by Community-Associated Methicillin-Resistant Staphylococcus aureus by Targeting α-Type Phenol-Soluble Modulins and α-Hemolysin. EBioMedicine 2018; 33:211-217. [PMID: 29936135 PMCID: PMC6085503 DOI: 10.1016/j.ebiom.2018.06.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 06/05/2018] [Accepted: 06/12/2018] [Indexed: 12/31/2022] Open
Abstract
Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA), typified by the pulse-field type USA300, is an emerging endemic pathogen that is spreading rapidly among healthy people. CA-MRSA causes skin and soft tissue infections, life-threatening necrotizing pneumonia and sepsis, and is remarkably resistant to many antibiotics. Here we show that engineered liposomes composed of naturally occurring sphingomyelin were able to sequester cytolytic toxins secreted by USA300 and prevent necrosis of human erythrocytes, peripheral blood mononuclear cells and bronchial epithelial cells. Mass spectrometric analysis revealed the capture by liposomes of phenol-soluble modulins, α-hemolysin and other toxins. Sphingomyelin liposomes prevented hemolysis induced by pure phenol-soluble modulin-α3, one of the main cytolytic components in the USA300 secretome. In contrast, sphingomyelin liposomes harboring a high cholesterol content (66 mol/%) were unable to protect human cells from phenol-soluble modulin-α3-induced lysis, however these liposomes efficiently sequestered the potent staphylococcal toxin α-hemolysin. In a murine cutaneous abscess model, a single dose of either type of liposomes was sufficient to significantly decrease tissue dermonecrosis. Our results provide further insights into the promising potential of tailored liposomal therapy in the battle against infectious diseases.
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Affiliation(s)
- Heidi Wolfmeier
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, 2259 Lower Mall Research Station, V6T1Z4 Vancouver, British Columbia, Canada
| | - Sarah C Mansour
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, 2259 Lower Mall Research Station, V6T1Z4 Vancouver, British Columbia, Canada
| | - Leo T Liu
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, 2259 Lower Mall Research Station, V6T1Z4 Vancouver, British Columbia, Canada
| | - Daniel Pletzer
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, 2259 Lower Mall Research Station, V6T1Z4 Vancouver, British Columbia, Canada
| | - Annette Draeger
- Institute of Anatomy, University of Bern, Baltzerstrasse 2, 3000 Bern, Switzerland
| | - Eduard B Babiychuk
- Institute of Anatomy, University of Bern, Baltzerstrasse 2, 3000 Bern, Switzerland
| | - Robert E W Hancock
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, 2259 Lower Mall Research Station, V6T1Z4 Vancouver, British Columbia, Canada.
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37
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Staphylococcus aureus Utilizes Host-Derived Lipoprotein Particles as Sources of Fatty Acids. J Bacteriol 2018; 200:JB.00728-17. [PMID: 29581406 DOI: 10.1128/jb.00728-17] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 03/13/2018] [Indexed: 11/20/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is a threat to global health. Consequently, much effort has focused on the development of new antimicrobials that target novel aspects of S. aureus physiology. Fatty acids are required to maintain cell viability, and bacteria synthesize fatty acids using the type II fatty acid synthesis (FASII) pathway. FASII is significantly different from human fatty acid synthesis, underscoring the therapeutic potential of inhibiting this pathway. However, many Gram-positive pathogens incorporate exogenous fatty acids, bypassing FASII inhibition and leaving the clinical potential of FASII inhibitors uncertain. Importantly, the source(s) of fatty acids available to pathogens within the host environment remains unclear. Fatty acids are transported throughout the body by lipoprotein particles in the form of triglycerides and esterified cholesterol. Thus, lipoproteins, such as low-density lipoprotein (LDL), represent a potentially rich source of exogenous fatty acids for S. aureus during infection. We sought to test the ability of LDLs to serve as a fatty acid source for S. aureus and show that cells cultured in the presence of human LDLs demonstrate increased tolerance to the FASII inhibitor triclosan. Using mass spectrometry, we observed that host-derived fatty acids present in the LDLs are incorporated into the staphylococcal membrane and that tolerance to triclosan is facilitated by the fatty acid kinase A, FakA, and Geh, a triacylglycerol lipase. Finally, we demonstrate that human LDLs support the growth of S. aureus fatty acid auxotrophs. Together, these results suggest that human lipoprotein particles are a viable source of exogenous fatty acids for S. aureus during infection.IMPORTANCE Inhibition of bacterial fatty acid synthesis is a promising approach to combating infections caused by S. aureus and other human pathogens. However, S. aureus incorporates exogenous fatty acids into its phospholipid bilayer. Therefore, the clinical utility of targeting bacterial fatty acid synthesis is debated. Moreover, the fatty acid reservoir(s) exploited by S. aureus is not well understood. Human low-density lipoprotein particles represent a particularly abundant in vivo source of fatty acids and are present in tissues that S. aureus colonizes. Herein, we establish that S. aureus is capable of utilizing the fatty acids present in low-density lipoproteins to bypass both chemical and genetic inhibition of fatty acid synthesis. These findings imply that S. aureus targets LDLs as a source of fatty acids during pathogenesis.
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Non-classical Protein Excretion Is Boosted by PSMα-Induced Cell Leakage. Cell Rep 2018; 20:1278-1286. [PMID: 28793253 DOI: 10.1016/j.celrep.2017.07.045] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 06/06/2017] [Accepted: 07/18/2017] [Indexed: 02/04/2023] Open
Abstract
Release of cytoplasmic proteins into the supernatant occurs both in bacteria and eukaryotes. Because the underlying mechanism remains unclear, the excretion of cytoplasmic proteins (ECP) has been referred to as "non-classical protein secretion." We show that none of the known specific protein transport systems of Gram-positive bacteria are involved in ECP. However, the expression of the cationic and amphipathic α-type phenol-soluble modulins (PSMs), particularly of PSMα2, significantly increase ECP, while PSMβ peptides or δ-toxin have no effect on ECP. Because psm expression is strictly controlled by the accessory gene regulator (agr), ECP is also reduced in agr-negative mutants. PSMα peptides damage the cytoplasmic membrane, as indicated by the release of not only CPs but also lipids, nucleic acids, and ATP. Thus, our results show that in Staphylococcus aureus, PSMα peptides non-specifically boost the translocation of CPs by their membrane-damaging activity.
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39
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Lin MH, Li CC, Shu JC, Chu HW, Liu CC, Wu CC. Exoproteome Profiling Reveals the Involvement of the Foldase PrsA in the Cell Surface Properties and Pathogenesis ofStaphylococcus aureus. Proteomics 2018; 18:e1700195. [DOI: 10.1002/pmic.201700195] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Revised: 01/08/2018] [Indexed: 12/15/2022]
Affiliation(s)
- Mei-Hui Lin
- Department of Medical Biotechnology and Laboratory Science; College of Medicine; Chang Gung University; Tao-Yuan Taiwan
- Department of Laboratory Medicine; Chang Gung Memorial Hospital; Linkou Tao-Yuan Taiwan
- Graduate Institute of Biomedical Sciences; College of Medicine; Chang Gung University; Tao-Yuan Taiwan
| | - Chi-Chun Li
- Department of Medical Biotechnology and Laboratory Science; College of Medicine; Chang Gung University; Tao-Yuan Taiwan
| | - Jwu-Ching Shu
- Department of Medical Biotechnology and Laboratory Science; College of Medicine; Chang Gung University; Tao-Yuan Taiwan
- Department of Laboratory Medicine; Chang Gung Memorial Hospital; Linkou Tao-Yuan Taiwan
- Graduate Institute of Biomedical Sciences; College of Medicine; Chang Gung University; Tao-Yuan Taiwan
| | - Hao-Wei Chu
- Department of Medical Biotechnology and Laboratory Science; College of Medicine; Chang Gung University; Tao-Yuan Taiwan
- Graduate Institute of Biomedical Sciences; College of Medicine; Chang Gung University; Tao-Yuan Taiwan
| | - Chao-Chin Liu
- Department of Medical Biotechnology and Laboratory Science; College of Medicine; Chang Gung University; Tao-Yuan Taiwan
- Graduate Institute of Biomedical Sciences; College of Medicine; Chang Gung University; Tao-Yuan Taiwan
| | - Chih-Ching Wu
- Department of Medical Biotechnology and Laboratory Science; College of Medicine; Chang Gung University; Tao-Yuan Taiwan
- Graduate Institute of Biomedical Sciences; College of Medicine; Chang Gung University; Tao-Yuan Taiwan
- Molecular Medicine Research Center; Chang Gung University; Tao-Yuan Taiwan
- Department of Otolaryngology-Head & Neck Surgery; Chang Gung Memorial Hospital; Linkou Tao-Yuan Taiwan
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40
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Kane TL, Carothers KE, Lee SW. Virulence Factor Targeting of the Bacterial Pathogen Staphylococcus aureus for Vaccine and Therapeutics. Curr Drug Targets 2018; 19:111-127. [PMID: 27894236 PMCID: PMC5957279 DOI: 10.2174/1389450117666161128123536] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 10/12/2016] [Accepted: 10/27/2016] [Indexed: 12/21/2022]
Abstract
BACKGROUND Staphylococcus aureus is a major bacterial pathogen capable of causing a range of infections in humans from gastrointestinal disease, skin and soft tissue infections, to severe outcomes such as sepsis. Staphylococcal infections in humans can be frequent and recurring, with treatments becoming less effective due to the growing persistence of antibiotic resistant S. aureus strains. Due to the prevalence of antibiotic resistance, and the current limitations on antibiotic development, an active and highly promising avenue of research has been to develop strategies to specifically inhibit the activity of virulence factors produced S. aureus as an alternative means to treat disease. OBJECTIVE In this review we specifically highlight several major virulence factors produced by S. aureus for which recent advances in antivirulence approaches may hold promise as an alternative means to treating diseases caused by this pathogen. Strategies to inhibit virulence factors can range from small molecule inhibitors, to antibodies, to mutant and toxoid forms of the virulence proteins. CONCLUSION The major prevalence of antibiotic resistant strains of S. aureus combined with the lack of new antibiotic discoveries highlight the need for vigorous research into alternative strategies to combat diseases caused by this highly successful pathogen. Current efforts to develop specific antivirulence strategies, vaccine approaches, and alternative therapies for treating severe disease caused by S. aureus have the potential to stem the tide against the limitations that we face in the post-antibiotic era.
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Affiliation(s)
- Trevor L. Kane
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Katelyn E. Carothers
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Shaun W. Lee
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN 46556, USA
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41
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Kaysen GA, Grimes B, Dalrymple LS, Chertow GM, Ishida JH, Delgado C, Segal M, Chiang J, Dwyer T, Johansen KL. Associations of lipoproteins with cardiovascular and infection-related outcomes in patients receiving hemodialysis. J Clin Lipidol 2017; 12:481-487.e14. [PMID: 29361496 DOI: 10.1016/j.jacl.2017.12.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 12/15/2017] [Accepted: 12/15/2017] [Indexed: 01/20/2023]
Abstract
BACKGROUND In hemodialysis (HD) patients, higher lipid levels are associated with lower mortality. Lipid-lowering therapy does not reduce all-cause mortality or cardiovascular (CV) mortality. Lipoproteins play a role in the innate immune system. Our objective was to determine whether protection from infection might counterbalance adverse CV outcomes associated with lipoproteins. METHODS We examined associations between serum apolipoprotein (Apo) A1, B, C2, C3, high-density lipoprotein and low-density lipoprotein (LDL) cholesterol and triglyceride levels and infectious mortality or hospitalization, CV mortality or hospitalization, and all-cause mortality in 433 prevalent HD patients. Cox models with time-varying apolipoprotein concentrations collected every 6 months for up to 2 years were used for analyses. RESULTS Median follow-up time for all-cause mortality was 2.7 years (25th-75th percentile range: 2.2-3.4 years). One hundred seventy-nine (41%) patients had an infection-related event. In multivariable models, higher Apo B and LDL were associated with lower risks of infection-related outcomes (hazard ratio Apo B 0.92 [95% confidence interval 0.86-0.99 per 10 mg/dL, P = .03]; hazard ratio LDL 0.93 [95% confidence interval 0.87-1.00 per 10 mg/dL, P = .05]). Sixty-three (15%) participants had a CV-related event. No significant associations were observed between lipoproteins and CV outcomes. Eighty-seven (20%) participants died. Higher Apo A1, Apo B, and Apo C3 were associated with lower risks of all-cause mortality. There was no interaction between the use of lipid-lowering medication and any of the outcomes. CONCLUSION Associations of lipoproteins with lower risk of serious infection accompanied by no significant association with CV events may help to explain the paradoxical association between lipids and survival and lack of benefit of lipid-lowering therapies in HD.
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Affiliation(s)
- George A Kaysen
- Division of Nephrology, Department of Medicine, University of California Davis School of Medicine, Davis, CA, USA; Department of Biochemistry and Molecular Medicine, University of California Davis School of Medicine, Davis, CA, USA.
| | - Barbara Grimes
- Department of Epidemiology and Biostatistics, University of California, San Francisco, CA, USA
| | | | - Glenn M Chertow
- Division of Nephrology, Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Julie H Ishida
- Division of Nephrology, Department of Medicine, University of California, San Francisco, CA, USA; Nephrology Section, San Francisco Veterans Affairs Medical Center, San Francisco, CA, USA
| | - Cynthia Delgado
- Division of Nephrology, Department of Medicine, University of California, San Francisco, CA, USA; Nephrology Section, San Francisco Veterans Affairs Medical Center, San Francisco, CA, USA
| | - Mark Segal
- Department of Epidemiology and Biostatistics, University of California, San Francisco, CA, USA
| | - Janet Chiang
- Endocrinology Section, San Francisco Veterans Affairs Medical Center, San Francisco, CA, USA; Division of Endocrinology, Department of Medicine, University of California, San Francisco, CA, USA
| | - Tjien Dwyer
- Division of Nephrology, Department of Medicine, University of California Davis School of Medicine, Davis, CA, USA
| | - Kirsten L Johansen
- Department of Epidemiology and Biostatistics, University of California, San Francisco, CA, USA; Division of Nephrology, Department of Medicine, University of California, San Francisco, CA, USA; Nephrology Section, San Francisco Veterans Affairs Medical Center, San Francisco, CA, USA
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42
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Lewis ML, Surewaard BGJ. Neutrophil evasion strategies by Streptococcus pneumoniae and Staphylococcus aureus. Cell Tissue Res 2017; 371:489-503. [PMID: 29204747 DOI: 10.1007/s00441-017-2737-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 11/06/2017] [Indexed: 02/05/2023]
Abstract
Humans are well equipped to defend themselves against bacteria. The innate immune system employs diverse mechanisms to recognize, control and initiate a response that can destroy millions of different microbes. Microbes that evade the sophisticated innate immune system are able to escape detection and could become pathogens. The pathogens Streptococcus pneumoniae and Staphylococcus aureus are particularly successful due to the development of a wide variety of virulence strategies for bacterial pathogenesis and they invest significant efforts towards mechanisms that allow for neutrophil evasion. Neutrophils are a primary cellular defense and can rapidly kill invading microbes, which is an indispensable function for maintaining host health. This review compares the key features of Streptococcus pneumoniae and Staphylococcus aureus in epidemiology, with a specific focus on virulence mechanisms utilized to evade neutrophils in bacterial pathogenesis. It is important to understand the complex interactions between pathogenic bacteria and neutrophils so that we can disrupt the ability of pathogens to cause disease.
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Affiliation(s)
- Megan L Lewis
- Department of Physiology & Pharmacology, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Bas G J Surewaard
- Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada. .,Department of Medical Microbiology, University Medical Centre, Utrecht, Netherlands.
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Wen D, Luo H, Li T, Wu C, Zhang J, Wang X, Zhang R. Cloning and characterization of an insect apolipoprotein (apolipophorin-II/I) involved in the host immune response of Antheraea pernyi. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2017; 77:221-228. [PMID: 28830681 DOI: 10.1016/j.dci.2017.08.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 08/18/2017] [Accepted: 08/19/2017] [Indexed: 06/07/2023]
Abstract
Apolipoproteins are protein components of lipoprotein particles, and are increasingly recognized to be functioning in the innate immune systems of both insects and mammals. Mammalian apolipoprotein B (apoB) is associated with a diverse range of innate immune defenses including suppression of bacterial pathogenesis, virus toxicity neutralization, and inhibition of cytokine releases from immune cells. However, little is known about apoB homologous insect apolipophorin-II/I (apoLp-II/I) in controlling of specific pathogen-host encounters such as microbial infections. In the present study, we describe cDNA cloning and characterization of an apoLp-II/I from Chinese oak silk worm, Antheraea pernyi. The apoLp-II/I cDNA is 10237bp in length, which possesses an open reading frame encoding 3305 amino acids. A consensus cleavage site RGRR presenting from Arg710 to Arg713 implies posttranslational cleavage of this protein. Ap-apoLp-II/I shares high sequence identities with apoLp-II/I in lepidoptera and other insects. In addition, considerable similarities also exist between Ap-apoLp-II/I and human apoB, which basically positioned in first 1000 residues of the amino termini. Tissue distribution and time-course expression results demonstrate that Ap-apoLp-II/I transcripts were detected predominantly in the fat body, less in epidermis and rarely in midgut, while the synthetic apoLp-II/I protein was abundant in hemocytes and plasma instead of the fatbody. Expression of Ap-apoLp-II/I was stimulated in response to bacterial challenge. In addition, our preliminary studies established a novel role for Ap-apoLp-II/I in regulating prophenoloxidase activation system. Taken together, apoLp-II/I may play an essential role in innate responses of Antheraea pernyi.
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Affiliation(s)
- Daihua Wen
- School of Life Science and Bio-pharmaceutics, Shenyang Pharmaceutical University, China; School of Medical Devices, Shenyang Pharmaceutical University, China
| | - Hao Luo
- School of Life Science and Bio-pharmaceutics, Shenyang Pharmaceutical University, China
| | - Tienan Li
- School of Life Science and Bio-pharmaceutics, Shenyang Pharmaceutical University, China
| | - Chunfu Wu
- School of Life Science and Bio-pharmaceutics, Shenyang Pharmaceutical University, China
| | - Jinghai Zhang
- School of Medical Devices, Shenyang Pharmaceutical University, China
| | - Xialu Wang
- School of Medical Devices, Shenyang Pharmaceutical University, China.
| | - Rong Zhang
- School of Life Science and Bio-pharmaceutics, Shenyang Pharmaceutical University, China.
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Horn J, Stelzner K, Rudel T, Fraunholz M. Inside job: Staphylococcus aureus host-pathogen interactions. Int J Med Microbiol 2017; 308:607-624. [PMID: 29217333 DOI: 10.1016/j.ijmm.2017.11.009] [Citation(s) in RCA: 136] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 11/17/2017] [Accepted: 11/21/2017] [Indexed: 12/21/2022] Open
Abstract
Staphylococcus aureus is a notorious opportunistic pathogen causing a plethora of diseases. Recent research established that once phagocytosed by neutrophils and macrophages, a certain percentage of S. aureus is able to survive within these phagocytes which thereby even may contribute to dissemination of the pathogen. S. aureus further induces its uptake by otherwise non-phagocytic cells and the ensuing intracellular cytotoxicity is suggested to lead to tissue destruction, whereas bacterial persistence within cells is thought to lead to immune evasion and chronicity of infections. We here review recent work on the S. aureus host pathogen interactions with a focus on the intracellular survival of the pathogen.
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Affiliation(s)
- Jessica Horn
- Chair of Microbiology, Biocenter, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Kathrin Stelzner
- Chair of Microbiology, Biocenter, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Thomas Rudel
- Chair of Microbiology, Biocenter, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Martin Fraunholz
- Chair of Microbiology, Biocenter, University of Würzburg, Am Hubland, 97074 Würzburg, Germany.
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Rom JS, Atwood DN, Beenken KE, Meeker DG, Loughran AJ, Spencer HJ, Lantz TL, Smeltzer MS. Impact of Staphylococcus aureus regulatory mutations that modulate biofilm formation in the USA300 strain LAC on virulence in a murine bacteremia model. Virulence 2017; 8:1776-1790. [PMID: 28910576 PMCID: PMC5810510 DOI: 10.1080/21505594.2017.1373926] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Staphylococcus aureus causes acute and chronic forms of infection, the latter often associated with formation of a biofilm. It has previously been demonstrated that mutation of atl, codY, rot, sarA, and sigB limits biofilm formation in the USA300 strain LAC while mutation of agr, fur, and mgrA has the opposite effect. Here we used a murine sepsis model to assess the impact of these same loci in acute infection. Mutation of agr, atl, and fur had no impact on virulence, while mutation of mgrA and rot increased virulence. In contrast, mutation of codY, sarA, and sigB significantly attenuated virulence. Mutation of sigB resulted in reduced accumulation of AgrA and SarA, while mutation of sarA resulted in reduced accumulation of AgrA, but this cannot account for the reduced virulence of sarA or sigB mutants because the isogenic agr mutant was not attenuated. Indeed, as assessed by accumulation of alpha toxin and protein A, all of the mutants we examined exhibited unique phenotypes by comparison to an agr mutant and to each other. Attenuation of the sarA, sigB and codY mutants was correlated with increased production of extracellular proteases and global changes in extracellular protein profiles. These results suggest that the inability to repress the production of extracellular proteases plays a key role in attenuating the virulence of S. aureus in acute as well as chronic, biofilm-associated infections, thus opening up the possibility that strategies aimed at the de-repression of protease production could be used to broad therapeutic advantage. They also suggest that the impact of codY, sarA, and sigB on protease production occurs via an agr-independent mechanism.
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Affiliation(s)
- Joseph S Rom
- a Department of Microbiology and Immunology , University of Arkansas for Medical Sciences , Little Rock , AR , USA
| | - Danielle N Atwood
- a Department of Microbiology and Immunology , University of Arkansas for Medical Sciences , Little Rock , AR , USA
| | - Karen E Beenken
- a Department of Microbiology and Immunology , University of Arkansas for Medical Sciences , Little Rock , AR , USA
| | - Daniel G Meeker
- a Department of Microbiology and Immunology , University of Arkansas for Medical Sciences , Little Rock , AR , USA
| | - Allister J Loughran
- a Department of Microbiology and Immunology , University of Arkansas for Medical Sciences , Little Rock , AR , USA
| | - Horace J Spencer
- b Department of Biostatistics , University of Arkansas for Medical Sciences , Little Rock , AR , USA
| | - Tamara L Lantz
- a Department of Microbiology and Immunology , University of Arkansas for Medical Sciences , Little Rock , AR , USA
| | - Mark S Smeltzer
- a Department of Microbiology and Immunology , University of Arkansas for Medical Sciences , Little Rock , AR , USA.,c Department of Orthopaedic Surgery , University of Arkansas for Medical Sciences , Little Rock , AR , USA.,d Department of Pathology , University of Arkansas for Medical Sciences , Little Rock , AR , USA
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Pollitt EJG, Diggle SP. Defining motility in the Staphylococci. Cell Mol Life Sci 2017; 74:2943-2958. [PMID: 28378043 PMCID: PMC5501909 DOI: 10.1007/s00018-017-2507-z] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 02/16/2017] [Accepted: 03/14/2017] [Indexed: 01/17/2023]
Abstract
The ability of bacteria to move is critical for their survival in diverse environments and multiple ways have evolved to achieve this. Two forms of motility have recently been described for Staphylococcus aureus, an organism previously considered to be non-motile. One form is called spreading, which is a type of sliding motility and the second form involves comet formation, which has many observable characteristics associated with gliding motility. Darting motility has also been observed in Staphylococcus epidermidis. This review describes how motility is defined and how we distinguish between passive and active motility. We discuss the characteristics of the various forms of Staphylococci motility, the molecular mechanisms involved and the potential future research directions.
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Affiliation(s)
- Eric J G Pollitt
- Department of Biomedical Science, Western Bank, University of Sheffield, Sheffield, UK
| | - Stephen P Diggle
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA.
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Surewaard BGJ, Kubes P. Measurement of bacterial capture and phagosome maturation of Kupffer cells by intravital microscopy. Methods 2017; 128:12-19. [PMID: 28522327 DOI: 10.1016/j.ymeth.2017.05.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 05/04/2017] [Accepted: 05/09/2017] [Indexed: 11/29/2022] Open
Abstract
It is central to the field of bacterial pathogenesis to define how bacteria are killed by phagocytic cells. During phagocytosis, the microbe is localized to the phagolysosome where crucial defense mechanisms such as acidification and production of reactive oxygen species (ROS) are initiated. This process has extensively been studied in vitro, however many resident tissue phagocytes will phenotypically change upon isolation from their natural environment. Therefore, interrogation of phagocytosis and phagosomal function of cells in the context of their natural tissue environment enhances our understanding of the biological process in vivo. This article outlines a real-time intravital microscopy protocol that utilizes fluorescent dyes to study the process of phagocytosis, which reveals acidification and oxidation of individual bacteria inside host cells of living animals. The novelty of this technique exists in use of bacteria that are covalently labelled with the fluorescent dyes Oxyburst and pHrodo, which respectively report on oxidation or acidification. Intravital microscopy is applied to visualize the uptake and subsequent oxidation or acidification of reporter bacteria in the organ of interest. Fluorescently labelled antibodies can be used to counter stain for host immune cells such as neutrophils and macrophages, along with reference stains to identify all bacteria. Although these assays were originally developed to assess the uptake and survival ofStaphylococcus aureusin liver resident macrophages (Kupffer cells), this protocol may be adapted to investigate any bacterium-host cell interaction.
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Affiliation(s)
- Bas G J Surewaard
- Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, Canada; Department of Medical Microbiology, University Medical Centre, Utrecht, Netherlands.
| | - Paul Kubes
- Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, Canada
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Mariathasan S, Tan MW. Antibody-Antibiotic Conjugates: A Novel Therapeutic Platform against Bacterial Infections. Trends Mol Med 2017; 23:135-149. [PMID: 28126271 DOI: 10.1016/j.molmed.2016.12.008] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 12/15/2016] [Accepted: 12/16/2016] [Indexed: 11/26/2022]
Abstract
Antibodies are potent components of the immune repertoire and have been successfully exploited to treat bacterial infections. Recently an antibody-antibiotic conjugate (AAC) that combines key attributes of an antibody and antibiotic has been shown to be efficacious against Staphylococcus aureus infection. An AAC has three components: an antibiotic payload to kill bacteria, an antibody to target delivery of the payload to bacteria, and a linker attaching the payload to the antibody. With increasing understanding of the biology and pathophysiology of S. aureus, this article highlights how this knowledge has led to the design principles of an efficacious AAC, and discusses how the AAC platform could be translationally applied to treat other perilous infectious diseases.
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Affiliation(s)
- Sanjeev Mariathasan
- Department of Late-Stage Oncology Biomarkers Development, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA.
| | - Man-Wah Tan
- Department of Infectious Diseases, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA.
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LukMF' is the major secreted leukocidin of bovine Staphylococcus aureus and is produced in vivo during bovine mastitis. Sci Rep 2016; 6:37759. [PMID: 27886237 PMCID: PMC5123576 DOI: 10.1038/srep37759] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 10/31/2016] [Indexed: 01/18/2023] Open
Abstract
Staphylococcus aureus is a major human and animal pathogen and a common cause of mastitis in cattle. S. aureus secretes several leukocidins that target bovine neutrophils, crucial effector cells in the defence against bacterial pathogens. In this study, we investigated the role of staphylococcal leukocidins in the pathogenesis of bovine S. aureus disease. We show that LukAB, in contrast to the γ-hemolysins, LukED, and LukMF′, was unable to kill bovine neutrophils, and identified CXCR2 as a bovine receptor for HlgAB and LukED. Furthermore, we assessed functional leukocidin secretion by bovine mastitis isolates and observed that, although leukocidin production was strain dependent, LukMF′ was most abundantly secreted and the major toxin killing bovine neutrophils. To determine the role of LukMF′ in bovine mastitis, cattle were challenged with high (S1444) or intermediate (S1449, S1463) LukMF′-producing isolates. Only animals infected with S1444 developed severe clinical symptoms. Importantly, LukM was produced in vivo during the course of infection and levels in milk were associated with the severity of mastitis. Altogether, these findings underline the importance of LukMF′ as a virulence factor and support the development of therapeutic approaches targeting LukMF′ to control S. aureus mastitis in cattle.
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