101
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Möller N, Ziesemer S, Hildebrandt P, Assenheimer N, Völker U, Hildebrandt JP. S. aureus alpha-toxin monomer binding and heptamer formation in host cell membranes - Do they determine sensitivity of airway epithelial cells toward the toxin? PLoS One 2020; 15:e0233854. [PMID: 32470006 PMCID: PMC7259691 DOI: 10.1371/journal.pone.0233854] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 05/13/2020] [Indexed: 11/18/2022] Open
Abstract
Alpha-toxin (Hla) is a major virulence factor of Staphylococcus aureus (S. aureus) and plays an important role in S. aureus-induced pneumonia. It binds as a monomer to the cell surface of eukaryotic host cells and forms heptameric transmembrane pores. Sensitivities toward the toxin of various types of potential host cells have been shown to vary substantially, and the reasons for these differences are unclear. We used three human model airway epithelial cell lines (16HBE14o-, S9, A549) to correlate cell sensitivity (measured as rate of paracellular gap formation in the cell layers) with Hla monomer binding, presence of the potential Hla receptors ADAM10 or α5β1 integrin, presence of the toxin-stabilizing factor caveolin-1 as well as plasma membrane lipid composition (phosphatidylserine/choline, sphingomyelin). The abundance of ADAM10 correlated best with gap formation or cell sensitivities, respectively, when the three cell types were compared. Caveolin-1 or α5β1 integrin did not correlate with toxin sensitivity. The relative abundance of sphingomyelin in plasma membranes may also be used as a proxi for cellular sensitivity against alpha-toxin as sphingomyelin abundances correlated well with the intensities of alpha-toxin mediated gap formation in the cell layers.
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Affiliation(s)
- Nils Möller
- Animal Physiology and Biochemistry, University of Greifswald, Greifswald, Germany
| | - Sabine Ziesemer
- Animal Physiology and Biochemistry, University of Greifswald, Greifswald, Germany
| | - Petra Hildebrandt
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | - Nadine Assenheimer
- Animal Physiology and Biochemistry, University of Greifswald, Greifswald, Germany
| | - Uwe Völker
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | - Jan-Peter Hildebrandt
- Animal Physiology and Biochemistry, University of Greifswald, Greifswald, Germany
- * E-mail:
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102
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Souza JSM, Lisboa ABP, Santos TM, Andrade MVS, Neves VBS, Teles-Souza J, Jesus HNR, Bezerra TG, Falcão VGO, Oliveira RC, Del-Bem LE. The evolution of ADAM gene family in eukaryotes. Genomics 2020; 112:3108-3116. [PMID: 32437852 DOI: 10.1016/j.ygeno.2020.05.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 03/17/2020] [Accepted: 05/08/2020] [Indexed: 12/12/2022]
Abstract
The ADAM (A Disintegrin And Metalloprotease) gene family encodes proteins with adhesion and proteolytic functions. ADAM proteins are associated with diseases like cancers. Twenty ADAM genes have been identified in humans. However, little is known about the evolution of the family. We analyzed the repertoire of ADAM genes in a vast number of eukaryotic genomes to clarify the main gene copy number expansions. For the first time, we provide compelling evidence that early-branching green algae (Mamiellophyceae) have ADAM genes, suggesting that they originated in the last common ancestor of eukaryotes, before the split of plants, fungi and animals. The ADAM family expanded in early metazoans, with the most significative gene expansion happening during the first steps of vertebrate evolution. We concluded that most of mammal ADAM diversity can be explained by gene duplications in early bone fish. Our data suggest that ADAM genes were lost early in green plant evolution.
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Affiliation(s)
- J S M Souza
- Biochemistry and Molecular Biology program, Institute of Health Sciences (ICS), Federal University of Bahia (UFBA), Salvador 40231-300, Brazil
| | - A B P Lisboa
- Biotechnology program, Institute of Health Sciences (ICS), Federal University of Bahia (UFBA), Salvador 40231-300, Brazil; Bioinformatics program, Institute of Biological Sciences (ICB), Federal University of Minas Gerais (UFMG), Belo Horizonte 31270-901, Brazil
| | - T M Santos
- Biochemistry and Molecular Biology program, Institute of Health Sciences (ICS), Federal University of Bahia (UFBA), Salvador 40231-300, Brazil; Bioinformatics program, Institute of Biological Sciences (ICB), Federal University of Minas Gerais (UFMG), Belo Horizonte 31270-901, Brazil
| | - M V S Andrade
- Biotechnology program, Institute of Health Sciences (ICS), Federal University of Bahia (UFBA), Salvador 40231-300, Brazil
| | - V B S Neves
- Biochemistry and Molecular Biology program, Institute of Health Sciences (ICS), Federal University of Bahia (UFBA), Salvador 40231-300, Brazil
| | - J Teles-Souza
- Biochemistry and Molecular Biology program, Institute of Health Sciences (ICS), Federal University of Bahia (UFBA), Salvador 40231-300, Brazil
| | - H N R Jesus
- Biochemistry and Molecular Biology program, Institute of Health Sciences (ICS), Federal University of Bahia (UFBA), Salvador 40231-300, Brazil
| | - T G Bezerra
- Biochemistry and Molecular Biology program, Institute of Health Sciences (ICS), Federal University of Bahia (UFBA), Salvador 40231-300, Brazil
| | - V G O Falcão
- Biotechnology program, Institute of Health Sciences (ICS), Federal University of Bahia (UFBA), Salvador 40231-300, Brazil
| | - R C Oliveira
- Biochemistry and Molecular Biology program, Institute of Health Sciences (ICS), Federal University of Bahia (UFBA), Salvador 40231-300, Brazil
| | - L E Del-Bem
- Institute of Health Sciences (ICS), Federal University of Bahia (UFBA), Salvador 40231-300, Brazil.
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103
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Liu J, Kozhaya L, Torres VJ, Unutmaz D, Lu M. Structure-based discovery of a small-molecule inhibitor of methicillin-resistant Staphylococcus aureus virulence. J Biol Chem 2020; 295:5944-5959. [PMID: 32179646 PMCID: PMC7196633 DOI: 10.1074/jbc.ra120.012697] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 03/06/2020] [Indexed: 01/07/2023] Open
Abstract
The rapid emergence and dissemination of methicillin-resistant Staphylococcus aureus (MRSA) strains poses a major threat to public health. MRSA possesses an arsenal of secreted host-damaging virulence factors that mediate pathogenicity and blunt immune defenses. Panton-Valentine leukocidin (PVL) and α-toxin are exotoxins that create lytic pores in the host cell membrane. They are recognized as being important for the development of invasive MRSA infections and are thus potential targets for antivirulence therapies. Here, we report the high-resolution X-ray crystal structures of both PVL and α-toxin in their soluble, monomeric, and oligomeric membrane-inserted pore states in complex with n-tetradecylphosphocholine (C14PC). The structures revealed two evolutionarily conserved phosphatidylcholine-binding mechanisms and their roles in modulating host cell attachment, oligomer assembly, and membrane perforation. Moreover, we demonstrate that the soluble C14PC compound protects primary human immune cells in vitro against cytolysis by PVL and α-toxin and hence may serve as the basis for the development of an antivirulence agent for managing MRSA infections.
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Affiliation(s)
- Jie Liu
- Public Health Research Institute, Department of Microbiology, Biochemistry, and Molecular Genetics, New Jersey Medical School, Rutgers University, Newark, New Jersey 07103
| | - Lina Kozhaya
- Jackson Laboratory for Genomic Medicine, Farmington, Connecticut 06032
| | - Victor J. Torres
- Department of Microbiology, New York University School of Medicine, New York, New York 10016
| | - Derya Unutmaz
- Jackson Laboratory for Genomic Medicine, Farmington, Connecticut 06032
| | - Min Lu
- Public Health Research Institute, Department of Microbiology, Biochemistry, and Molecular Genetics, New Jersey Medical School, Rutgers University, Newark, New Jersey 07103, To whom correspondence should be addressed:
Public Health Research Institute, Dept. of Microbiology, Biochemistry, and Molecular Genetics, New Jersey Medical School, Newark, NJ 07103. Tel.:
973-854-3260; E-mail:
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104
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Shittu A, Deinhardt‐Emmer S, Vas Nunes J, Niemann S, Grobusch MP, Schaumburg F. Tropical pyomyositis: an update. Trop Med Int Health 2020; 25:660-665. [DOI: 10.1111/tmi.13395] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Adebayo Shittu
- Department of Microbiology Obafemi Awolowo University Ile‐Ife Nigeria
- Institute of Medical Microbiology University Hospital Münster Münster Germany
| | | | - Jonathan Vas Nunes
- Masanga Hospital Masanga Sierra Leone
- Masanga Medical Research Unit Masanga Sierra Leone
| | - Silke Niemann
- Institute of Medical Microbiology University Hospital Münster Münster Germany
| | - Martin P. Grobusch
- Masanga Medical Research Unit Masanga Sierra Leone
- Center of Tropical Medicine University of Amsterdam Amsterdam The Netherlands
| | - Frieder Schaumburg
- Institute of Medical Microbiology University Hospital Münster Münster Germany
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105
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Tromp AT, van Strijp JAG. Studying Staphylococcal Leukocidins: A Challenging Endeavor. Front Microbiol 2020; 11:611. [PMID: 32351474 PMCID: PMC7174503 DOI: 10.3389/fmicb.2020.00611] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 03/19/2020] [Indexed: 01/01/2023] Open
Abstract
Staphylococcus aureus is a well-known colonizer of the human skin and nose, but also a human pathogen that causes a wide spectrum of diseases. It is well established that S. aureus secretes an arsenal of virulence factors that have evolved to circumvent the human immune system. A major group of S. aureus virulence factors is the bi-component β-barrel pore-forming toxins, also known as leukocidins. These pore-forming toxins target specific cells of the innate and adaptive immune system by interacting with specific receptors expressed on the cell membrane. Even though still heavily debated, clinical and epidemiological studies suggest the involvement of one of the bi-component toxin, Panton-Valentine Leukocidin (PVL), as an important factor contributing to the epidemic spread and increased virulence of CA-MRSA strains. However, the host- and cell-specificity of PVL and other leukocidins, and the lack of adequate in vivo models, fuels the controversy and impairs the appropriate assessment of their role in S. aureus pathophysiology. Currently, the mechanisms of pore-formation and the contribution of PVL and other leukocidins to S. aureus pathophysiology are incompletely understood. This review summarizes our current understanding of leukocidin pore-formation, knowledge gaps, and highlights recent findings identifying novel host-factors involved in the toxin-host interface. As a result, this review furthers emphasizes the complexity behind S. aureus leukocidin cytotoxicity and the challenges associated in the quest to study and understand these major virulence factors.
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Affiliation(s)
- Angelino T Tromp
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Jos A G van Strijp
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, Netherlands
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106
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von Hoven G, Qin Q, Neukirch C, Husmann M, Hellmann N. Staphylococcus aureus α-toxin: small pore, large consequences. Biol Chem 2020; 400:1261-1276. [PMID: 30951494 DOI: 10.1515/hsz-2018-0472] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 03/26/2019] [Indexed: 12/14/2022]
Abstract
The small β-pore-forming α-toxin, also termed α-hemolysin or Hla is considered to be an important virulence factor of Staphylococcus aureus. Perforation of the plasma membrane (PM) by Hla leads to uncontrolled flux of ions and water. Already a small number of toxin pores seems to be sufficient to induce complex cellular responses, many of which depend on the efflux of potassium. In this article, we discuss the implications of secondary membrane lesions, for example, by endogenous channels, for Hla-mediated toxicity, for calcium-influx and membrane repair. Activation of purinergic receptors has been proposed to be a major contributor to the lytic effects of various pore forming proteins, but new findings raise doubts that this holds true for Hla. However, the recently discovered cellular pore forming proteins gasdermin D and Mixed lineage kinase domain-like pseudokinase (MLKL) which perforate the PM from the cytosolic side might contribute to both calcium-influx-dependent damage and membrane repair. Activation of endogenous pore forming proteins by Hla above a threshold concentration could explain the apparent dependence of pore characteristics on toxin concentrations. If secondary membrane damage in the aftermath of Hla-attack contributes significantly to overall PM permeability, it might be an interesting target for new therapeutic approaches.
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Affiliation(s)
- Gisela von Hoven
- Institute of Medical Microbiology and Hygiene, University Medical Center of the Johannes Gutenberg-University Mainz, Obere Zahlbacher Straße 67, 55131 Mainz, Germany
| | - Qianqian Qin
- Institute of Medical Microbiology and Hygiene, University Medical Center of the Johannes Gutenberg-University Mainz, Obere Zahlbacher Straße 67, 55131 Mainz, Germany
| | - Claudia Neukirch
- Institute of Medical Microbiology and Hygiene, University Medical Center of the Johannes Gutenberg-University Mainz, Obere Zahlbacher Straße 67, 55131 Mainz, Germany
| | - Matthias Husmann
- Institute of Medical Microbiology and Hygiene, University Medical Center of the Johannes Gutenberg-University Mainz, Obere Zahlbacher Straße 67, 55131 Mainz, Germany
| | - Nadja Hellmann
- Institute for Pharmacy and Biochemistry, Johannes Gutenberg-University Mainz, Johann-Joachim Becher-Weg 30, 55128 Mainz, Germany
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107
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Hammad SG, El-Gazzar MG, Abutaleb NS, Li D, Ramming I, Shekhar A, Abdel-Halim M, Elrazaz EZ, Seleem MN, Bilitewski U, Abouzid KAM, El-Hossary EM. Synthesis and antimicrobial evaluation of new halogenated 1,3-Thiazolidin-4-ones. Bioorg Chem 2019; 95:103517. [PMID: 31884138 DOI: 10.1016/j.bioorg.2019.103517] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 12/08/2019] [Accepted: 12/16/2019] [Indexed: 12/22/2022]
Abstract
The ongoing prevalence of multidrug-resistant bacterial pathogens requires the development of new effective antibacterial agents. In this study, two series of halogenated 1,3-thiazolidin-4-ones were synthesized and characterized. All the synthesized thiazolidinone derivatives were evaluated for their antimicrobial activity. Biological screening of the tested compounds revealed the antibacterial activity of the chlorinated thiazolidinones 4a, 4b and 4c against Escherichia coli TolC-mutant, with MIC values of 16 µg/mL. A combination of a sub-inhibitory concentration of colistin (0.25 × MIC) with compounds 4a, 4b or 4c showed antibacterial activity against different Gram-negative bacteria (MICs = 4-16 µg/mL). Interestingly, compounds 4a, 4b and 4c were not cytotoxic to murine fibroblasts and Caco-2 cells. The chlorinated thiazolidinone derivative 16d demonstrated a bacteriostatic activity against a panel of pathogenic Gram-positive bacteria, including clinical isolates of methicillin and vancomycin-resistant Staphylococcus aureus, Listeria monocytogenes and multidrug-resistant Staphylococcus epidermidis (MICs = 8 - 64 µg/mL), with no cytotoxicity against both Caco-2 and L929 cells. Compound 16d was superior to vancomycin in disruption of the pre-formed MRSA biofilm. Furthermore, the three fluorinated thiazolidinone derivatives 26c, 30c and 33c showed a hindrance to hemolysin activity, without cytotoxicity against L929 cells.
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Affiliation(s)
- Shaymaa G Hammad
- National Centre for Radiation Research & Technology (NCRRT), Egyptian Atomic Energy Authority (EAEA), Ahmed El-Zomor St. 3, El-Zohoor Dist., Nasr City, Cairo 11765, Egypt
| | - Marwa G El-Gazzar
- National Centre for Radiation Research & Technology (NCRRT), Egyptian Atomic Energy Authority (EAEA), Ahmed El-Zomor St. 3, El-Zohoor Dist., Nasr City, Cairo 11765, Egypt.
| | - Nader S Abutaleb
- Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, West Lafayette, IN 47907, USA
| | - Daoyi Li
- Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, West Lafayette, IN 47907, USA
| | - Isabell Ramming
- Helmholtz Center for Infection Research, WG Compound Profiling and Screening (COPS), Inhoffenstr. 7, 38124 Braunschweig, Germany
| | - Aditya Shekhar
- Helmholtz Center for Infection Research, WG Compound Profiling and Screening (COPS), Inhoffenstr. 7, 38124 Braunschweig, Germany
| | - Mohammad Abdel-Halim
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy and Biotechnology, German University in Cairo, Cairo 11835, Egypt
| | - Eman Z Elrazaz
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Ain-Shams University, Abbassia, Cairo 11566, Egypt
| | - Mohamed N Seleem
- Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, West Lafayette, IN 47907, USA; Purdue Institute of Inflammation, Immunology, and Infectious Diseases, West Lafayette, IN 47907, USA
| | - Ursula Bilitewski
- Helmholtz Center for Infection Research, WG Compound Profiling and Screening (COPS), Inhoffenstr. 7, 38124 Braunschweig, Germany
| | - Khaled A M Abouzid
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Ain-Shams University, Abbassia, Cairo 11566, Egypt; Department of Organic and Medicinal Chemistry, Faculty of Pharmacy, University of Sadat City, Menoufia, Egypt.
| | - Ebaa M El-Hossary
- National Centre for Radiation Research & Technology (NCRRT), Egyptian Atomic Energy Authority (EAEA), Ahmed El-Zomor St. 3, El-Zohoor Dist., Nasr City, Cairo 11765, Egypt
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108
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Shah J, Rouaud F, Guerrera D, Vasileva E, Popov LM, Kelley WL, Rubinstein E, Carette JE, Amieva MR, Citi S. A Dock-and-Lock Mechanism Clusters ADAM10 at Cell-Cell Junctions to Promote α-Toxin Cytotoxicity. Cell Rep 2019; 25:2132-2147.e7. [PMID: 30463011 DOI: 10.1016/j.celrep.2018.10.088] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 10/01/2018] [Accepted: 10/24/2018] [Indexed: 01/08/2023] Open
Abstract
We previously identified PLEKHA7 and other junctional proteins as host factors mediating death by S. aureus α-toxin, but the mechanism through which junctions promote toxicity was unclear. Using cell biological and biochemical methods, we now show that ADAM10 is docked to junctions by its transmembrane partner Tspan33, whose cytoplasmic C terminus binds to the WW domain of PLEKHA7 in the presence of PDZD11. ADAM10 is locked at junctions through binding of its cytoplasmic C terminus to afadin. Junctionally clustered ADAM10 supports the efficient formation of stable toxin pores. Instead, disruption of the PLEKHA7-PDZD11 complex inhibits ADAM10 and toxin junctional clustering. This promotes toxin pore removal from the cell surface through an actin- and macropinocytosis-dependent process, resulting in cell recovery from initial injury and survival. These results uncover a dock-and-lock molecular mechanism to target ADAM10 to junctions and provide a paradigm for how junctions regulate transmembrane receptors through their clustering.
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Affiliation(s)
- Jimit Shah
- Department of Cell Biology, Faculty of Sciences, University of Geneva, 1211-4 Geneva, Switzerland; Institute for Genetics and Genomics of Geneva (iGE3), University of Geneva, 1211-4 Geneva, Switzerland
| | - Florian Rouaud
- Department of Cell Biology, Faculty of Sciences, University of Geneva, 1211-4 Geneva, Switzerland; Institute for Genetics and Genomics of Geneva (iGE3), University of Geneva, 1211-4 Geneva, Switzerland
| | - Diego Guerrera
- Department of Cell Biology, Faculty of Sciences, University of Geneva, 1211-4 Geneva, Switzerland; Institute for Genetics and Genomics of Geneva (iGE3), University of Geneva, 1211-4 Geneva, Switzerland
| | - Ekaterina Vasileva
- Department of Cell Biology, Faculty of Sciences, University of Geneva, 1211-4 Geneva, Switzerland; Institute for Genetics and Genomics of Geneva (iGE3), University of Geneva, 1211-4 Geneva, Switzerland
| | - Lauren M Popov
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - William L Kelley
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, 1211-4 Geneva, Switzerland
| | - Eric Rubinstein
- INSERM, Université Paris-Sud, UMRS_935, 94807 Villejuif Cedex, France
| | - Jan E Carette
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Manuel R Amieva
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Sandra Citi
- Department of Cell Biology, Faculty of Sciences, University of Geneva, 1211-4 Geneva, Switzerland; Institute for Genetics and Genomics of Geneva (iGE3), University of Geneva, 1211-4 Geneva, Switzerland.
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109
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Tsuiji M, Shiohara K, Takei Y, Shinohara Y, Nemoto S, Yamaguchi S, Kanto M, Itoh S, Oku T, Miyashita M, Seyama Y, Kurihara M, Tsuji T. Selective Cytotoxicity of Staphylococcal α-Hemolysin (α-Toxin) against Human Leukocyte Populations. Biol Pharm Bull 2019; 42:982-988. [PMID: 31155595 DOI: 10.1248/bpb.b18-01024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Staphylococcus aureus produces a variety of exoproteins that interfere with host immune systems. We attempted to purify cytotoxins against human leukocytic cells from the culture supernatant of S. aureus by a combination of ammonium sulfate precipitation, ion-exchange chromatography on a CM-cellulose column and HPLC on a Mono S 5/50 column. A major protein possessing cytotoxicity to HL60 human promyelocytic leukemia cells was purified, and the protein was identified as α-hemolysin (Hla, α-toxin) based on its molecular weight (34 kDa) and N-terminal amino acid sequence. Flow cytometric analysis suggested differential cytotoxicity of Hla against different human peripheral blood leukocyte populations. After cell fractionation with density-gradient centrifugation, we found that peripheral blood mononuclear cells (PBMCs) were more susceptible to Hla than polymorphonuclear leukocytes. Moreover, cell surface marker analysis suggested that Hla exhibited slightly higher cytotoxicity against CD14-positive PBMCs (mainly monocytes) than CD3- or CD19-positive cells (T or B lymphocytes). From these results, we conclude that human leukocytes have different susceptibility to Hla depending on their cell lineages, and thereby the toxin may modulate the host immune response.
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Affiliation(s)
- Makoto Tsuiji
- Department of Microbiology, Hoshi University School of Pharmacy and Pharmaceutical Sciences
| | - Kazuyuki Shiohara
- Department of Microbiology, Hoshi University School of Pharmacy and Pharmaceutical Sciences
| | - Yoshinori Takei
- Department of Microbiology, Hoshi University School of Pharmacy and Pharmaceutical Sciences
| | - Yoshinori Shinohara
- Department of Microbiology, Hoshi University School of Pharmacy and Pharmaceutical Sciences
| | - Shigeyoshi Nemoto
- Department of Microbiology, Hoshi University School of Pharmacy and Pharmaceutical Sciences
| | - Satoshi Yamaguchi
- Department of Microbiology, Hoshi University School of Pharmacy and Pharmaceutical Sciences
| | - Masanori Kanto
- Department of Microbiology, Hoshi University School of Pharmacy and Pharmaceutical Sciences
| | - Saotomo Itoh
- Department of Microbiology, Hoshi University School of Pharmacy and Pharmaceutical Sciences
| | - Teruaki Oku
- Department of Microbiology, Hoshi University School of Pharmacy and Pharmaceutical Sciences
| | - Masahiro Miyashita
- Department of Clinical Chemistry, Hoshi University School of Pharmacy and Pharmaceutical Sciences
| | - Yoshiyuki Seyama
- Department of Clinical Chemistry, Hoshi University School of Pharmacy and Pharmaceutical Sciences
| | | | - Tsutomu Tsuji
- Department of Microbiology, Hoshi University School of Pharmacy and Pharmaceutical Sciences
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110
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Campoccia D, Mirzaei R, Montanaro L, Arciola CR. Hijacking of immune defences by biofilms: a multifront strategy. BIOFOULING 2019; 35:1055-1074. [PMID: 31762334 DOI: 10.1080/08927014.2019.1689964] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 10/05/2019] [Accepted: 11/04/2019] [Indexed: 06/10/2023]
Abstract
Biofilm formation by pathogens and opportunistic bacteria is the basis of persistent or recurrent infections. Up to 80% of bacterial infections in humans are associated with biofilms. Despite the efficiency of the evolved and complex human defence system against planktonic bacteria, biofilms are capable of subverting host defences. The immune system is not completely effective in opposing bacteria and preventing infection. Increasing attention is being focussed on the mechanisms enabling bacterial biofilms to skew the coordinate action of humoral and cell mediated responses. Knowledge of the interactions between biofilm bacteria and the immune system is critical to effectively address biofilm infections, which have multiplied over the years with the spread of biomaterials in medicine. In this article, the latest information on the interactions between bacterial biofilms and immune cells is examined and the areas where of information is still lacking are explored.
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Affiliation(s)
- Davide Campoccia
- Laboratorio di Patologia delle Infezioni Associate all'Impianto, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy
| | - Rasoul Mirzaei
- Department of Microbiology, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Lucio Montanaro
- Laboratorio di Patologia delle Infezioni Associate all'Impianto, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy
- Department of Experimental, Diagnostic, and Specialty Medicine, University of Bologna, Bologna, Italy
| | - Carla Renata Arciola
- Laboratorio di Patologia delle Infezioni Associate all'Impianto, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy
- Department of Experimental, Diagnostic, and Specialty Medicine, University of Bologna, Bologna, Italy
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111
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Omersa N, Podobnik M, Anderluh G. Inhibition of Pore-Forming Proteins. Toxins (Basel) 2019; 11:E545. [PMID: 31546810 PMCID: PMC6784129 DOI: 10.3390/toxins11090545] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 08/27/2019] [Accepted: 09/10/2019] [Indexed: 12/16/2022] Open
Abstract
Perforation of cellular membranes by pore-forming proteins can affect cell physiology, tissue integrity, or immune response. Since many pore-forming proteins are toxins or highly potent virulence factors, they represent an attractive target for the development of molecules that neutralize their actions with high efficacy. There has been an assortment of inhibitors developed to specifically obstruct the activity of pore-forming proteins, in addition to vaccination and antibiotics that serve as a plausible treatment for the majority of diseases caused by bacterial infections. Here we review a wide range of potential inhibitors that can specifically and effectively block the activity of pore-forming proteins, from small molecules to more specific macromolecular systems, such as synthetic nanoparticles, antibodies, antibody mimetics, polyvalent inhibitors, and dominant negative mutants. We discuss their mechanism of inhibition, as well as advantages and disadvantages.
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Affiliation(s)
- Neža Omersa
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia.
| | - Marjetka Podobnik
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia.
| | - Gregor Anderluh
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia.
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112
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Guo L, Rondina MT. The Era of Thromboinflammation: Platelets Are Dynamic Sensors and Effector Cells During Infectious Diseases. Front Immunol 2019; 10:2204. [PMID: 31572400 PMCID: PMC6753373 DOI: 10.3389/fimmu.2019.02204] [Citation(s) in RCA: 132] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 08/30/2019] [Indexed: 12/12/2022] Open
Abstract
Platelets are anucleate cells produced by megakaryocytes. In recent years, a robust body of literature supports the evolving role of platelets as key sentinel and effector cells in infectious diseases, especially critical in bridging hemostatic, inflammatory, and immune continuums. Upon intravascular pathogen invasion, platelets can directly sense viral, parasitic, and bacterial infections through pattern recognition receptors and integrin receptors or pathogen: immunoglobulin complexes through Fc and complement receptors—although our understanding of these interactions remains incomplete. Constantly scanning for areas of injury or inflammation as they circulate in the vasculature, platelets also indirectly respond to pathogen invasion through interactions with leukocytes and the endothelium. Following antigen recognition, platelets often become activated. Through a diverse repertoire of mechanisms, activated platelets can directly sequester or kill pathogens, or facilitate pathogen clearance by activating macrophages and neutrophils, promoting neutrophil extracellular traps (NETs) formation, forming platelet aggregates and microthrombi. At times, however, platelet activation may also be injurious to the host, exacerbating inflammation and promoting endothelial damage and thrombosis. There are many gaps in our understandings of the role of platelets in infectious diseases. However, with the emergence of advanced technologies, our knowledge is increasing. In the current review, we mainly discuss these evolving roles of platelets under four different infectious pathogen infections, of which are dengue, malaria, Esterichia coli (E. coli) and staphylococcus aureus S. aureus, highlighting the complex interplay of these processes with hemostatic and thrombotic pathways.
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Affiliation(s)
- Li Guo
- University of Utah Molecular Medicine Program, Salt Lake City, UT, United States
| | - Matthew T Rondina
- University of Utah Molecular Medicine Program, Salt Lake City, UT, United States.,Department of Internal Medicine, University of Utah, Salt Lake City, UT, United States.,Department of Pathology, University of Utah, Salt Lake City, UT, United States.,George E. Wahlen VAMC Department of Internal Medicine and GRECC, Salt Lake City, UT, United States
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113
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Todd OA, Peters BM. Candida albicans and Staphylococcus aureus Pathogenicity and Polymicrobial Interactions: Lessons beyond Koch's Postulates. J Fungi (Basel) 2019; 5:E81. [PMID: 31487793 PMCID: PMC6787713 DOI: 10.3390/jof5030081] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 09/02/2019] [Accepted: 09/03/2019] [Indexed: 01/01/2023] Open
Abstract
While Koch's Postulates have established rules for microbial pathogenesis that have been extremely beneficial for monomicrobial infections, new studies regarding polymicrobial pathogenesis defy these standards. The explosion of phylogenetic sequence data has revolutionized concepts of microbial interactions on and within the host. However, there remains a paucity of functional follow-up studies to delineate mechanisms driven by such interactions and how they shape health or disease. That said, one particular microbial pairing, the fungal opportunist Candida albicans and the bacterial pathogen Staphylococcus aureus, has received much attention over the last decade. Therefore, the objective of this review is to discuss the multi-faceted mechanisms employed by these two ubiquitous human pathogens during polymicrobial growth, including how they: establish and persist in inter-Kingdom biofilms, tolerate antimicrobial therapy, co-invade host tissue, exacerbate quorum sensing and staphylococcal toxin production, and elicit infectious synergism. Commentary regarding new challenges and remaining questions related to future discovery of this fascinating fungal-bacterial interaction is also provided.
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Affiliation(s)
- Olivia A Todd
- Integrated Program in Biomedical Sciences, College of Graduate Health Sciences, University of Tennessee Health Science Center, Memphis, TN 38163, USA.
| | - Brian M Peters
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN 38163, USA.
- Department of Microbiology, Immunology, and Biochemistry, College of Medicine, University of Tennessee Health Science Center, Memphis, TN 38163, USA.
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114
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Alfano DN, Bubeck Wardenburg J. Another Score for the Pore: S. aureus Leukocidins Take a Shot on the Endothelium. Cell Host Microbe 2019; 25:351-353. [PMID: 30870619 DOI: 10.1016/j.chom.2019.02.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Sepsis is a complex disease characterized by severe endothelial injury. In this issue of Cell Host & Microbe, Lubkin et al. (2019) reveal that an interaction between Staphylococcus aureus leukocidins and their cellular receptor DARC on endothelial cells leads to vascular injury, shedding light on pathogen-driven contributions to sepsis.
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Affiliation(s)
- Danielle N Alfano
- Department of Pediatrics, Washington University School of Medicine, 660 S. Euclid Avenue, Box 8208, St. Louis, MO 63110, USA
| | - Juliane Bubeck Wardenburg
- Department of Pediatrics, Washington University School of Medicine, 660 S. Euclid Avenue, Box 8208, St. Louis, MO 63110, USA.
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115
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Wilson JW, Rolland AD, Klausen GM, Prell JS. Ion Mobility-Mass Spectrometry Reveals That α-Hemolysin from Staphylococcus aureus Simultaneously Forms Hexameric and Heptameric Complexes in Detergent Micelle Solutions. Anal Chem 2019; 91:10204-10211. [PMID: 31282652 DOI: 10.1021/acs.analchem.9b02243] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Many soluble and membrane proteins form symmetrical homooligomeric complexes. However, determining the oligomeric state of protein complexes can be difficult. Alpha-hemolysin (αHL) from Staphylococcus aureus is a symmetrical homooligomeric protein toxin that forms transmembrane β-barrel pores in host cell membranes. The stable pore structure of αHL has also been exploited in vitro as a nanopore tool. Early structural experiments suggested αHL forms a hexameric pore, while more recent X-ray crystal structure and solution studies have identified a heptameric pore structure. Here, using native ion mobility-mass spectrometry (IM-MS) we find that αHL simultaneously forms hexameric and heptameric oligomers in both tetraethylene glycol monooctyl ether (C8E4) and tetradecylphosphocholine (FOS-14) detergent solutions. We also analyze intact detergent micelle-embedded αHL porelike complexes by native IM-MS without the need to fully strip the detergent micelle, which can cause significant gas-phase unfolding. The highly congested native mass spectra are deconvolved using Fourier- and Gábor-transform (FT and GT) methods to determine charge states and detergent stoichiometry distributions. The intact αHL micelle complexes are found to contain oligomeric state-proportional numbers of detergent molecules. This evidence, combined with IM data and results from vacuum molecular dynamics simulations, is consistent with both the hexamer and the heptamer forming porelike complexes. The ability of αHL to form both oligomeric states simultaneously has implications for its use as a nanopore tool and its pore formation mechanism in vivo. This study also demonstrates more generally the power of FT and GT to deconvolve the charge state and stoichiometry distributions of polydisperse ions.
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Affiliation(s)
- Jesse W Wilson
- Department of Chemistry and Biochemistry , University of Oregon , 1253 University of Oregon , Eugene , Oregon 97403-1253 , United States
| | - Amber D Rolland
- Department of Chemistry and Biochemistry , University of Oregon , 1253 University of Oregon , Eugene , Oregon 97403-1253 , United States
| | - Grant M Klausen
- Department of Chemistry and Biochemistry , University of Oregon , 1253 University of Oregon , Eugene , Oregon 97403-1253 , United States
| | - James S Prell
- Department of Chemistry and Biochemistry , University of Oregon , 1253 University of Oregon , Eugene , Oregon 97403-1253 , United States.,Materials Science Institute , University of Oregon , 1252 University of Oregon , Eugene , Oregon 97403-1252 , United States
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116
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Blümel E, Willerslev-Olsen A, Gluud M, Lindahl LM, Fredholm S, Nastasi C, Krejsgaard T, Surewaard BGJ, Koralov SB, Hu T, Persson JL, Bonefeld CM, Geisler C, Iversen L, Becker JC, Andersen MH, Woetmann A, Buus TB, Ødum N. Staphylococcal alpha-toxin tilts the balance between malignant and non-malignant CD4 + T cells in cutaneous T-cell lymphoma. Oncoimmunology 2019; 8:e1641387. [PMID: 31646088 PMCID: PMC6791457 DOI: 10.1080/2162402x.2019.1641387] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 06/03/2019] [Accepted: 07/02/2019] [Indexed: 02/08/2023] Open
Abstract
Staphylococcus aureus is implicated in disease progression in cutaneous T-cell lymphoma (CTCL). Here, we demonstrate that malignant T cell lines derived from CTCL patients as well as primary malignant CD4+ T cells from Sézary syndrome patients are considerably more resistant to alpha-toxin-induced cell death than their non-malignant counterparts. Thus, in a subset of Sézary syndrome patients the ratio between malignant and non-malignant CD4+ T cells increases significantly following exposure to alpha-toxin. Whereas toxin-induced cell death is ADAM10 dependent in healthy CD4+ T cells, resistance to alpha-toxin in malignant T cells involves both downregulation of ADAM10 as well as other resistance mechanisms. In conclusion, we provide first evidence that Staphylococcus aureus derived alpha-toxin can tilt the balance between malignant and non-malignant CD4+ T cells in CTCL patients. Consequently, alpha-toxin may promote disease progression through positive selection of malignant CD4+ T cells, identifying alpha-toxin as a putative drug target in CTCL.
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Affiliation(s)
- Edda Blümel
- LEO Foundation Skin Immunology Research Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Andreas Willerslev-Olsen
- LEO Foundation Skin Immunology Research Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Maria Gluud
- LEO Foundation Skin Immunology Research Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Lise M. Lindahl
- Department of Dermatology, Aarhus University Hospital, Aarhus, Denmark
| | - Simon Fredholm
- LEO Foundation Skin Immunology Research Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Claudia Nastasi
- LEO Foundation Skin Immunology Research Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Thorbjørn Krejsgaard
- LEO Foundation Skin Immunology Research Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Bas G. J. Surewaard
- Department of Physiology and Pharmacology, Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Canada
| | - Sergei B. Koralov
- Department of Pathology, New York University School of Medicine, New York, NY, USA
| | - Tengpeng Hu
- LEO Foundation Skin Immunology Research Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Jenny L. Persson
- Clinical Research Center, Lund University, Lund, Sweden
- Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Charlotte Menné Bonefeld
- LEO Foundation Skin Immunology Research Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Carsten Geisler
- LEO Foundation Skin Immunology Research Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Lars Iversen
- Department of Dermatology, Aarhus University Hospital, Aarhus, Denmark
| | - Jürgen C. Becker
- Translational Skin Cancer Research, German Cancer Consortium (DKTK), University Hospital Essen and Deutsches Krebsforschungszentrum (DKFZ), Essen, Germany
| | - Mads Hald Andersen
- LEO Foundation Skin Immunology Research Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
- Center for Cancer Immune Therapy (CCIT), Department of Hematology and Oncology, Copenhagen University Hospital, Herlev Hospital, Herlev, Denmark
| | - Anders Woetmann
- LEO Foundation Skin Immunology Research Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Terkild Brink Buus
- LEO Foundation Skin Immunology Research Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Niels Ødum
- LEO Foundation Skin Immunology Research Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
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117
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Zhang H, Jiang JM, Han L, Lao YZ, Zheng D, Chen YY, Wan SJ, Zheng CW, Tan HS, Li ZG, Xu HX. Uncariitannin, a polyphenolic polymer from Uncaria gambier, attenuates Staphylococcus aureus virulence through an MgrA-mediated regulation of α-hemolysin. Pharmacol Res 2019; 147:104328. [PMID: 31288080 DOI: 10.1016/j.phrs.2019.104328] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2018] [Revised: 06/20/2019] [Accepted: 06/21/2019] [Indexed: 10/26/2022]
Abstract
A global transcriptional regulator, MgrA, was previously identified as a key determinant of virulence in Staphylococcus aureus. An 80% EtOH extract of Uncaria gambier was found to attenuate the virulence of S. aureus via its effects on MgrA. Using bioassay-guided fractionation, a polyphenolic polymer, uncariitannin, was found to be the main bioactive constituent of the extract, and its structure was characterized using spectral and chemical analysis. The molecular weight and polydispersity of uncariitannin were determined by gel permeation chromatography-refractive index-light scattering analysis. An electrophoretic mobility shift assay showed that uncariitannin could effectively inhibit the interaction of MgrA with DNA in a dose-dependent manner. Treatment with uncariitannin could decrease the mRNA and protein levels of Hla in both the S. aureus Newman and USA300 LAC strains. Further analysis of Hla expression levels in the Newman ΔmgrA and Newman ΔmgrA/pYJ335-mgrA strains indicated that uncariitannin altered Hla expression primarily in an MgrA-dependent manner. A mouse model of infection indicated that uncariitannin could attenuate MRSA virulence. In conclusion, uncariitannin may be a potential candidate for further development as an antivirulence agent for the treatment of S. aureus infection.
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Affiliation(s)
- Hong Zhang
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, PR China; Engineering Research Centre of Shanghai Colleges for TCM New Drug Discovery, Shanghai, 201203, PR China
| | - Jia-Ming Jiang
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, PR China; Engineering Research Centre of Shanghai Colleges for TCM New Drug Discovery, Shanghai, 201203, PR China
| | - Li Han
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, PR China; Engineering Research Centre of Shanghai Colleges for TCM New Drug Discovery, Shanghai, 201203, PR China
| | - Yuan-Zhi Lao
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, PR China; Engineering Research Centre of Shanghai Colleges for TCM New Drug Discovery, Shanghai, 201203, PR China
| | - Dan Zheng
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, PR China; Engineering Research Centre of Shanghai Colleges for TCM New Drug Discovery, Shanghai, 201203, PR China
| | - Yu-Yu Chen
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, PR China; Engineering Research Centre of Shanghai Colleges for TCM New Drug Discovery, Shanghai, 201203, PR China
| | - Shi-Jie Wan
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, PR China; Engineering Research Centre of Shanghai Colleges for TCM New Drug Discovery, Shanghai, 201203, PR China
| | - Chang-Wu Zheng
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, PR China; Engineering Research Centre of Shanghai Colleges for TCM New Drug Discovery, Shanghai, 201203, PR China
| | - Hong-Sheng Tan
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, PR China; Engineering Research Centre of Shanghai Colleges for TCM New Drug Discovery, Shanghai, 201203, PR China
| | - Zi-Gang Li
- School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, Guangdong, 518055, PR China.
| | - Hong-Xi Xu
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, PR China; Engineering Research Centre of Shanghai Colleges for TCM New Drug Discovery, Shanghai, 201203, PR China.
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118
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Staphylococcus aureus Toxins: From Their Pathogenic Roles to Anti-virulence Therapy Using Natural Products. BIOTECHNOL BIOPROC E 2019. [DOI: 10.1007/s12257-019-0059-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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119
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Sward EW, Fones EM, Spaan RR, Pallister KB, Haller BL, Guerra FE, Zurek OW, Nygaard TK, Voyich JM. Staphylococcus aureus SaeR/S-Regulated Factors Decrease Monocyte-Derived Tumor Necrosis Factor-α to Reduce Neutrophil Bactericidal Activity. J Infect Dis 2019; 217:943-952. [PMID: 29272502 DOI: 10.1093/infdis/jix652] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 12/17/2017] [Indexed: 12/11/2022] Open
Abstract
Background The ability of Staphylococcus aureus to evade killing by human neutrophils significantly contributes to disease progression. In this study, we characterize an influential role for the S. aureus SaeR/S 2-component gene regulatory system in suppressing monocyte production of tumor necrosis factor alpha (TNF-α) to subsequently influence human neutrophil priming. Methods Using flow cytometry and TNF-α specific enzyme-linked immunosorbent assays we identify the primary cellular source of TNF-α in human blood and in purified peripheral blood mononuclear cells (PBMCs) during interaction with USA300 and an isogenic saeR/S deletion mutant (USA300∆saeR/S). Assays with conditioned media from USA300 and USA300∆saeR/S exposed PBMCs were used to investigate priming on neutrophil bactericidal activity. Results TNF-α production from monocytes was significantly reduced following challenge with USA300 compared to USA300∆saeR/S. We observed that priming of neutrophils using conditioned medium from peripheral blood mononuclear cells stimulated with USA300∆saeR/S significantly increased neutrophil bactericidal activity against USA300 relative to unprimed neutrophils and neutrophils primed with USA300 conditioned medium. The increased neutrophil bactericidal activity was associated with enhanced reactive oxygen species production that was significantly influenced by elevated TNF-α concentrations. Conclusions Our findings identify an immune evasion strategy used by S. aureus to impede neutrophil priming and subsequent bactericidal activity.
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Affiliation(s)
- Eli W Sward
- Department of Microbiology and Immunology, Montana State University, Bozeman
| | - Elizabeth M Fones
- Department of Microbiology and Immunology, Montana State University, Bozeman
| | - Russel R Spaan
- Department of Microbiology and Immunology, Montana State University, Bozeman
| | - Kyler B Pallister
- Department of Microbiology and Immunology, Montana State University, Bozeman
| | - Brandon L Haller
- Department of Microbiology and Immunology, Montana State University, Bozeman
| | - Fermin E Guerra
- Department of Microbiology and Immunology, Montana State University, Bozeman
| | - Oliwia W Zurek
- Infectious Disease Department, Genentech Inc, South San Francisco, California
| | - Tyler K Nygaard
- Department of Microbiology and Immunology, Montana State University, Bozeman
| | - Jovanka M Voyich
- Department of Microbiology and Immunology, Montana State University, Bozeman
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120
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Hilburger CE, Jacobs ML, Lewis KR, Peruzzi JA, Kamat NP. Controlling Secretion in Artificial Cells with a Membrane AND Gate. ACS Synth Biol 2019; 8:1224-1230. [PMID: 31051071 DOI: 10.1021/acssynbio.8b00435] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The assembly of channel proteins into vesicle membranes is a useful strategy to control activities of vesicle-based systems. Here, we developed a membrane AND gate that responds to both a fatty acid and a pore-forming channel protein to induce the release of encapsulated cargo. We explored how membrane composition affects the functional assembly of α-hemolysin into phospholipid vesicles as a function of oleic acid content and α-hemolysin concentration. We then showed that we could induce α-hemolysin assembly when we added oleic acid micelles to a specific composition of phospholipid vesicles. Finally, we demonstrated that our membrane AND gate could be coupled to a gene expression system. Our study provides a new method to control the temporal dynamics of vesicle permeability by controlling when the functional assembly of a channel protein into synthetic vesicles occurs. Furthermore, a membrane AND gate that utilizes membrane-associating biomolecules introduces a new way to implement Boolean logic that should complement genetic logic circuits and ultimately enhance the capabilities of artificial cellular systems.
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121
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Astley R, Miller FC, Mursalin MH, Coburn PS, Callegan MC. An Eye on Staphylococcus aureus Toxins: Roles in Ocular Damage and Inflammation. Toxins (Basel) 2019; 11:E356. [PMID: 31248125 PMCID: PMC6628431 DOI: 10.3390/toxins11060356] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 06/13/2019] [Accepted: 06/15/2019] [Indexed: 12/12/2022] Open
Abstract
Staphylococcus aureus (S. aureus) is a common pathogen of the eye, capable of infecting external tissues such as the tear duct, conjunctiva, and the cornea, as well the inner and more delicate anterior and posterior chambers. S. aureus produces numerous toxins and enzymes capable of causing profound damage to tissues and organs, as well as modulating the immune response to these infections. Unfortunately, in the context of ocular infections, this can mean blindness for the patient. The role of α-toxin in corneal infection (keratitis) and infection of the interior of the eye (endophthalmitis) has been well established by comparing virulence in animal models and α-toxin-deficient isogenic mutants with their wild-type parental strains. The importance of other toxins, such as β-toxin, γ-toxin, and Panton-Valentine leukocidin (PVL), have been analyzed to a lesser degree and their roles in eye infections are less clear. Other toxins such as the phenol-soluble modulins have yet to be examined in any animal models for their contributions to virulence in eye infections. This review discusses the state of current knowledge of the roles of S. aureus toxins in eye infections and the controversies existing as a result of the use of different infection models. The strengths and limitations of these ocular infection models are discussed, as well as the need for physiological relevance in the study of staphylococcal toxins in these models.
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Affiliation(s)
- Roger Astley
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
| | - Frederick C Miller
- Department of Cell Biology and Department of Family and Preventive Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
| | - Md Huzzatul Mursalin
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
| | - Phillip S Coburn
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
| | - Michelle C Callegan
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
- Dean McGee Eye Institute, 608 Stanton L. Young Blvd., DMEI PA-418, Oklahoma City, OK 73104, USA.
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122
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Keogh RA, Zapf RL, Trzeciak E, Null GG, Wiemels RE, Carroll RK. Novel Regulation of Alpha-Toxin and the Phenol-Soluble Modulins by Peptidyl-Prolyl cis/trans Isomerase Enzymes in Staphylococcus aureus. Toxins (Basel) 2019; 11:toxins11060343. [PMID: 31208155 PMCID: PMC6628628 DOI: 10.3390/toxins11060343] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 06/10/2019] [Accepted: 06/12/2019] [Indexed: 02/07/2023] Open
Abstract
Peptidyl-prolyl cis/trans isomerases (PPIases) are enzymes that catalyze the cis-to-trans isomerization around proline bonds, allowing proteins to fold into their correct confirmation. Previously, we identified two PPIase enzymes in Staphylococcus aureus (PpiB and PrsA) that are involved in the regulation of virulence determinants and have shown that PpiB contributes to S. aureus virulence in a murine abscess model of infection. Here, we further examine the role of these PPIases in S. aureus virulence and, in particular, their regulation of hemolytic toxins. Using murine abscess and systemic models of infection, we show that a ppiB mutant in a USA300 background is attenuated for virulence but that a prsA mutant is not. Deletion of the ppiB gene leads to decreased bacterial survival in macrophages and nasal epithelial cells, while there is no significant difference when prsA is deleted. Analysis of culture supernatants reveals that a ppiB mutant strain has reduced levels of the phenol-soluble modulins and that both ppiB and prsA mutants have reduced alpha-toxin activity. Finally, we perform immunoprecipitation to identify cellular targets of PpiB and PrsA. Results suggest a novel role for PpiB in S. aureus protein secretion. Collectively, our results demonstrate that PpiB and PrsA influence S. aureus toxins via distinct mechanisms, and that PpiB but not PrsA contributes to disease.
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Affiliation(s)
- Rebecca A Keogh
- Department of Biological Sciences, Ohio University, Athens, OH 45701, USA.
| | - Rachel L Zapf
- Department of Biological Sciences, Ohio University, Athens, OH 45701, USA.
| | - Emily Trzeciak
- Department of Biological Sciences, Ohio University, Athens, OH 45701, USA.
| | - Gillian G Null
- Department of Biological Sciences, Ohio University, Athens, OH 45701, USA.
| | - Richard E Wiemels
- Department of Biological Sciences, Ohio University, Athens, OH 45701, USA.
| | - Ronan K Carroll
- Department of Biological Sciences, Ohio University, Athens, OH 45701, USA.
- The Infectious and Tropical Disease Institute, Ohio University, Athens, OH 45701, USA.
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123
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The Role of Streptococcal and Staphylococcal Exotoxins and Proteases in Human Necrotizing Soft Tissue Infections. Toxins (Basel) 2019; 11:toxins11060332. [PMID: 31212697 PMCID: PMC6628391 DOI: 10.3390/toxins11060332] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 06/04/2019] [Accepted: 06/10/2019] [Indexed: 12/31/2022] Open
Abstract
Necrotizing soft tissue infections (NSTIs) are critical clinical conditions characterized by extensive necrosis of any layer of the soft tissue and systemic toxicity. Group A streptococci (GAS) and Staphylococcus aureus are two major pathogens associated with monomicrobial NSTIs. In the tissue environment, both Gram-positive bacteria secrete a variety of molecules, including pore-forming exotoxins, superantigens, and proteases with cytolytic and immunomodulatory functions. The present review summarizes the current knowledge about streptococcal and staphylococcal toxins in NSTIs with a special focus on their contribution to disease progression, tissue pathology, and immune evasion strategies.
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124
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Ming T, Geng L, Feng Y, Lu C, Zhou J, Li Y, Zhang D, He S, Li Y, Cheong L, Su X. iTRAQ-Based Quantitative Proteomic Profiling of Staphylococcus aureus Under Different Osmotic Stress Conditions. Front Microbiol 2019; 10:1082. [PMID: 31191466 PMCID: PMC6549500 DOI: 10.3389/fmicb.2019.01082] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 04/29/2019] [Indexed: 02/03/2023] Open
Abstract
Staphylococcus aureus (S. aureus) is an extremely halotolerant pathogenic bacterium with high osmotic stress tolerance, and it is frequently encountered in aquatic production and preservation. However, the mechanism underlying the extremely high osmotic stress tolerance of S. aureus remains unclear. In this study, the isobaric tags for relative and absolute quantification (iTRAQ) method was used to identify the differentially expressed proteins (DEPs) under different sodium chloride (NaCl) concentrations. Compared with the control group (0% NaCl), the 10 and 20% NaCl groups had 484 DEPs and 750 DEPs, respectively. Compared with the 10% NaCl group, the 20% NaCl group had 361 DEPs. Among the DEPs, proteins involved in fatty acid synthesis, proline/glycine betaine biosynthesis and transportation, stress tolerance, cell wall biosynthesis and the TCA cycle were upregulated, whereas proteins associated with biofilm formation and pathogenic infections were downregulated. The results obtained in this study indicate that under extremely high osmotic stress, modification of the cell membrane structure, increased biosynthesis and transportation of osmotic protectants, and redistribution of energy metabolism contribute to the osmotic stress tolerance of S. aureus, and the infectious ability of the bacteria may be limited. The aim of this study was to provide new insight into how S. aureus tolerates the high-salt conditions involved in aquatic production and preservation.
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Affiliation(s)
- Tinghong Ming
- School of Marine Sciences, Ningbo University, Ningbo, China.,College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, China
| | - Lingxin Geng
- School of Marine Sciences, Ningbo University, Ningbo, China.,College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, China
| | - Ying Feng
- School of Marine Sciences, Ningbo University, Ningbo, China
| | - Chenyang Lu
- School of Marine Sciences, Ningbo University, Ningbo, China
| | - Jun Zhou
- School of Marine Sciences, Ningbo University, Ningbo, China
| | - Yanyan Li
- Department of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Dijun Zhang
- Zhejiang Zhengli Antuo Biotechnology Co., Ltd, Ningbo, China
| | - Shan He
- School of Marine Sciences, Ningbo University, Ningbo, China
| | - Ye Li
- School of Marine Sciences, Ningbo University, Ningbo, China
| | - Lingzhi Cheong
- College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, China
| | - Xiurong Su
- School of Marine Sciences, Ningbo University, Ningbo, China
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125
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Abstract
Community-acquired pneumonia (CAP) is a leading cause of morbidity and mortality worldwide. Despite broad literature including basic and translational scientific studies, many gaps in our understanding of host-pathogen interactions remain. In this review, pathogen virulence factors that drive lung infection and injury are discussed in relation to their associated host immune pathways. CAP epidemiology is considered, with a focus on Staphylococcus aureus and Streptococcus pneumoniae as primary pathogens. Bacterial factors involved in nasal colonization and subsequent virulence are illuminated. A particular emphasis is placed on bacterial pore-forming toxins, host cell death, and inflammasome activation. Identified host-pathogen interactions are then examined by linking pathogen factors to aberrant host response pathways in the context of acute lung injury in both primary and secondary infection. While much is known regarding bacterial virulence and host immune responses, CAP management is still limited to mostly supportive care. It is likely that improvements in therapy will be derived from combinatorial targeting of both pathogen virulence factors and host immunomodulation.
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126
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Simonis A, Schubert-Unkmeir A. The role of acid sphingomyelinase and modulation of sphingolipid metabolism in bacterial infection. Biol Chem 2019; 399:1135-1146. [PMID: 29924727 DOI: 10.1515/hsz-2018-0200] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 06/14/2018] [Indexed: 01/01/2023]
Abstract
Acid sphingomyelinase (ASM) is a key enzyme in sphingolipid metabolism that converts sphingomyelin to ceramide, thereby modulating membrane structures and signal transduction. Bacterial pathogens can manipulate ASM activity and function, and use host sphingolipids during multiple steps of their infection process. An increase in ceramides upon infection results in the formation of ceramide-enriched membrane platforms that serve to cluster receptor molecules and organize intracellular signaling molecules, thus facilitating bacterial uptake. In this review, we focus on how extracellular bacterial pathogens target ASM and modulate membrane properties and signaling pathways to gain entry into eukaryotic cells or induce cell death. We describe how intracellular pathogens interfere with the intralysosomal functions of ASM to favor replication and survival. In addition, bacteria utilize their own sphingomyelinases as virulence factors to modulate sphingolipid metabolism. The potential of ASM as a target for treating bacterial infections is also discussed.
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Affiliation(s)
- Alexander Simonis
- Division of Hematology, University Hospital Zurich, Rämistrasse 100, 8091 Zürich, Switzerland
| | - Alexandra Schubert-Unkmeir
- Institute of Hygiene and Microbiology, University of Würzburg, Josef-Schneider-Straße 2, D-97080 Würzburg, Germany
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127
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Keitsch S, Riethmüller J, Soddemann M, Sehl C, Wilker B, Edwards MJ, Caldwell CC, Fraunholz M, Gulbins E, Becker KA. Pulmonary infection of cystic fibrosis mice with Staphylococcus aureus requires expression of α-toxin. Biol Chem 2019; 399:1203-1213. [PMID: 29613852 DOI: 10.1515/hsz-2018-0161] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2018] [Accepted: 03/28/2018] [Indexed: 01/25/2023]
Abstract
Pulmonary infections of cystic fibrosis (CF) patients with Staphylococcus aureus (S. aureus) occur very early in the disease. The molecular details that cause infection-susceptibility of CF patients to and mediate infection with S. aureus are poorly characterized. Therefore, we aimed to identify the role of α-toxin, a major S. aureus toxin, for pulmonary infection of CF mice. Infection with S. aureus JE2 resulted in severe pneumonia in CF mice, while wildtype mice were almost unaffected. Deficiency of α-toxin in JE2-Δhla reduced the pathogenicity of S. aureus in CF mice. However, CF mice were still more susceptible to the mutant S. aureus strain than wildtype mice. The S. aureus JE2 induced a marked increase of ceramide and a downregulation of sphingosine and acid ceramidase expression in bronchi of CF mice. Deletion of α-toxin reduced these changes after infection of CF mice. Similar changes were observed in wildtype mice, but at much lower levels. Our data indicate that expression of α-toxin is a major factor causing S. aureus infections in CF mice. Wildtype S. aureus induces a marked increase of ceramide and a reduction of sphingosine and acid ceramidase expression in bronchial epithelial cells of wildtype and CF mice, changes that determine infection susceptibility.
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Affiliation(s)
- Simone Keitsch
- Department of Molecular Biology, Medical School, University of Duisburg-Essen, Hufelandstrasse 55, D-45122 Essen, Germany
| | - Joachim Riethmüller
- Center for Pediatric Clinical Studies, Children's Clinic, University of Tübingen, Hoppe-Seyler-Str. 1, D-72076 Tübingen, Germany
| | - Matthias Soddemann
- Department of Molecular Biology, Medical School, University of Duisburg-Essen, Hufelandstrasse 55, D-45122 Essen, Germany
| | - Carolin Sehl
- Department of Molecular Biology, Medical School, University of Duisburg-Essen, Hufelandstrasse 55, D-45122 Essen, Germany
| | - Barbara Wilker
- Department of Molecular Biology, Medical School, University of Duisburg-Essen, Hufelandstrasse 55, D-45122 Essen, Germany
| | - Michael J Edwards
- Department of Surgery, University of Cincinnati, College of Medicine, 231 Albert Sabin Way, Cincinnati, OH 45267-0558, USA
| | - Charles C Caldwell
- Department of Surgery, University of Cincinnati, College of Medicine, 231 Albert Sabin Way, Cincinnati, OH 45267-0558, USA
| | - Martin Fraunholz
- Chair of Microbiology, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Erich Gulbins
- Department of Molecular Biology, Medical School, University of Duisburg-Essen, Hufelandstrasse 55, D-45122 Essen, Germany.,Department of Surgery, University of Cincinnati, College of Medicine, 231 Albert Sabin Way, Cincinnati, OH 45267-0558, USA
| | - Katrin Anne Becker
- Department of Molecular Biology, Medical School, University of Duisburg-Essen, Hufelandstrasse 55, D-45122 Essen, Germany
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128
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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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129
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Koo S, Cheley S, Bayley H. Redirecting Pore Assembly of Staphylococcal α-Hemolysin by Protein Engineering. ACS CENTRAL SCIENCE 2019; 5:629-639. [PMID: 31041382 PMCID: PMC6487460 DOI: 10.1021/acscentsci.8b00910] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Indexed: 05/03/2023]
Abstract
α-Hemolysin (αHL), a β-barrel pore-forming toxin (βPFT), is secreted as a water-soluble monomer by Staphylococcus aureus. Upon binding to receptors on target cell membranes, αHL assembles to form heptameric membrane-spanning pores. We have previously engineered αHL to create a protease-activatable toxin that is activated by site-specific proteolysis including by tumor proteases. In this study, we redesigned αHL so that it requires 2-fold activation on target cells through (i) binding to specific receptors, and (ii) extracellular proteolytic cleavage. To assess our strategy, we constructed a fusion protein of αHL with galectin-1 (αHLG1, αHL-Galectin-1 chimera). αHLG1 was cytolytic toward cells that lack a receptor for wild-type αHL. We then constructed protease-activatable mutants of αHLG1 (PAMαHLG1s). PAMαHLG1s were activated by matrix metalloproteinase 2 (MMP-2) and had approximately 50-fold higher cytolytic activity toward MMP-2 overexpressing cells (HT-1080 cells) than toward non-overexpressing cells (HL-60 cells). Our approach provides a novel strategy for tailoring pore-forming toxins for therapeutic applications.
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Affiliation(s)
- Sunwoo Koo
- Department
of Neuroscience and Experimental Therapeutics, Texas A&M University Health Science Center, 8447 Riverside Parkway, Bryan, Texas 77807, United States
- E-mail: . Phone: 1-979-436-0381
| | - Stephen Cheley
- Department
of Pharmacology, Alberta Diabetes Institute, University of Alberta, Edmonton, T6G 2E1 Alberta, Canada
| | - Hagan Bayley
- Department
of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield
Road, Oxford, OX1 3TA England, United Kingdom
- E-mail: . Phone: +44 1865 285101
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130
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He Y, Li R, Li H, Zhang S, Dai W, Wu Q, Jiang L, Zheng Z, Shen S, Chen X, Zhu Y, Wang J, Pang Z. Erythroliposomes: Integrated Hybrid Nanovesicles Composed of Erythrocyte Membranes and Artificial Lipid Membranes for Pore-Forming Toxin Clearance. ACS NANO 2019; 13:4148-4159. [PMID: 30855941 DOI: 10.1021/acsnano.8b08964] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Pore-forming toxins (PFTs) are the most common bacterial virulence proteins and play a significant role in the pathogenesis of bacterial infections; thus, PFTs are an attractive therapeutic target in bacterial infections. Inspired by the pore-forming process and mechanism of PFTs, we designed an integrated hybrid nanovesicle-the erythroliposome (called the RM-PL)-for PFT detoxification by fusing natural red blood cell (RBC) membranes with artificial lipid membranes. The lipid and RBC membranes were mutually beneficial when integrated into a hybrid nanovesicle structure. The RBC membrane endowed RM-PLs with the capacity for detoxification, while the PEGylated lipid membrane stabilized the RM-PLs and greatly improved the detoxification capacity of the RBC membrane. With α-hemolysin (Hlα) as a model PFT, we demonstrated that RM-PLs could not only significantly reduce the toxicity of Hlα to erythrocytes in vitro but also effectively sponge Hlα in vivo and rescue mice from Hlα-induced damage. Moreover, the high detoxification capacity of RM-PLs was shown to be partly related to the expression of the Hlα receptor protein, a disintegrin and metalloproteinase domain-containing protein 10 on the RBC membrane. Consequently, as a component integrating natural and artificial materials, the erythroliposome nanoplatform inspires potential strategies for antivirulence therapy.
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Affiliation(s)
- Yuwei He
- Department of Pharmaceutics, School of Pharmacy , Fudan University and Key Laboratory of Smart Drug Delivery, Ministry of Education , Shanghai 201203 , China
| | - Ruixiang Li
- Innovation Research Institute of Traditional Chinese Medicine , Shanghai University of Traditional Chinese Medicine , Shanghai 201203 , China
| | - Haichun Li
- Department of Pharmaceutics, School of Pharmacy , Fudan University and Key Laboratory of Smart Drug Delivery, Ministry of Education , Shanghai 201203 , China
| | - Shuya Zhang
- Department of Pharmaceutics, School of Pharmacy , Fudan University and Key Laboratory of Smart Drug Delivery, Ministry of Education , Shanghai 201203 , China
| | - Wentao Dai
- Shanghai Center for Bioinformation Technology , Shanghai Industrial Technology Institute , Shanghai 201203 , China
| | - Qian Wu
- Shanghai Center for Bioinformation Technology , Shanghai Industrial Technology Institute , Shanghai 201203 , China
| | - Lixian Jiang
- Innovation Research Institute of Traditional Chinese Medicine , Shanghai University of Traditional Chinese Medicine , Shanghai 201203 , China
| | - Zicong Zheng
- Department of Pharmaceutics, School of Pharmacy , Fudan University and Key Laboratory of Smart Drug Delivery, Ministry of Education , Shanghai 201203 , China
| | - Shun Shen
- Department of Pharmaceutics, School of Pharmacy , Fudan University and Key Laboratory of Smart Drug Delivery, Ministry of Education , Shanghai 201203 , China
| | - Xing Chen
- Department of Pharmaceutics, School of Pharmacy , Fudan University and Key Laboratory of Smart Drug Delivery, Ministry of Education , Shanghai 201203 , China
| | - Yuefei Zhu
- Department of Pharmaceutics, School of Pharmacy , Fudan University and Key Laboratory of Smart Drug Delivery, Ministry of Education , Shanghai 201203 , China
| | - Jianxin Wang
- Department of Pharmaceutics, School of Pharmacy , Fudan University and Key Laboratory of Smart Drug Delivery, Ministry of Education , Shanghai 201203 , China
- Institute of Integrated Chinese and Western Medicine , Fudan University , Shanghai 200040 , China
| | - Zhiqing Pang
- Department of Pharmaceutics, School of Pharmacy , Fudan University and Key Laboratory of Smart Drug Delivery, Ministry of Education , Shanghai 201203 , China
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131
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Seike S, Takehara M, Kobayashi K, Nagahama M. Clostridium perfringens Delta-Toxin Damages the Mouse Small Intestine. Toxins (Basel) 2019; 11:toxins11040232. [PMID: 31013617 PMCID: PMC6520758 DOI: 10.3390/toxins11040232] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 04/08/2019] [Accepted: 04/17/2019] [Indexed: 12/13/2022] Open
Abstract
Clostridium perfringens strains B and C cause fatal intestinal diseases in animals. The secreted pore-forming toxin delta-toxin is one of the virulence factors of the strains, but the mechanism of intestinal pathogenesis is unclear. Here, we investigated the effects of delta-toxin on the mouse ileal loop. Delta-toxin caused fluid accumulation and intestinal permeability to fluorescein isothiocyanate (FITC)-dextran in the mouse ileal loop in a dose- and time-dependent manner. Treatment with delta-toxin induced significant histological damage and shortening of villi. Delta-toxin activates a disintegrin and metalloprotease (ADAM) 10, leading to the cleavage of E-cadherin, the epithelial adherens junction protein, in human intestinal epithelial Caco-2 cells. In this study, E-cadherin immunostaining in mouse intestinal epithelial cells was almost undetectable 1 h after toxin treatment. ADAM10 inhibitor (GI254023X) blocked the toxin-induced fluid accumulation and E-cadherin loss in the mouse ileal loop. Delta-toxin stimulated the shedding of intestinal epithelial cells. The shedding cells showed the accumulation of E-cadherin in intracellular vesicles and the increased expression of active caspase-3. Our findings demonstrate that delta-toxin causes intestinal epithelial cell damage through the loss of E-cadherin cleaved by ADAM10.
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Affiliation(s)
- Soshi Seike
- Laboratory of Molecular Microbiological Science, Faculty of Pharmaceutical Sciences, Hiroshima International University, Kure, Hiroshima 737-0112, Japan.
| | - Masaya Takehara
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan.
| | - Keiko Kobayashi
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan.
| | - Masahiro Nagahama
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan.
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132
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Nasser A, Moradi M, Jazireian P, Safari H, Alizadeh-Sani M, Pourmand MR, Azimi T. Staphylococcus aureus versus neutrophil: Scrutiny of ancient combat. Microb Pathog 2019; 131:259-269. [PMID: 31002964 DOI: 10.1016/j.micpath.2019.04.026] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 04/12/2019] [Accepted: 04/15/2019] [Indexed: 12/11/2022]
Abstract
Staphylococcus aureus (S.aureus) is a Gram-positive bacterium that causes many infections and diseases. This pathogen can cause many types of infections such as impetigo, toxic shock syndrome toxin (TSST1), pneumonia, endocarditis, and autoimmune diseases like lupus erythematosus and can infect other healthy individuals. In the pathogenic process, colonization is a main risk factor for invasive diseases. Various factors including the cell wall-associated factors and receptors of the epithelial cells facilitate adhesion and colonization of this pathogen. S. aureus has many enzymes, toxins, and strategies to evade from the immune system either by an enzyme that lyses cellular component or by hiding from the immune system via surface antigens like protein A and second immunoglobulin-binding protein (Sbi). The strategies of this bacterium can be divided into five groups: A: Inhibit neutrophil recruitment B: Inhibit phagocytosis C: Inhibit killing by ROS, D: Neutrophil killing, and E: Resistance to antimicrobial peptide. On the other hand, innate immune system via neutrophils, the most important polymorphonuclear leukocytes, fights against bacterial cells by neutrophil extracellular trap (NET). In this review, we try to explain the role of each factor in immune evasion.
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Affiliation(s)
- Ahmad Nasser
- Microbiology Research center, Ilam University of Medical Sciences, Ilam, Iran; Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Melika Moradi
- Department of Bacteriology and Virology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Parham Jazireian
- Department of Biology, University Campus 2,University of Guilan, Rasht, Iran
| | - Hossein Safari
- Health Promotion Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Mahmood Alizadeh-Sani
- Food Safety and Hygiene Division, Environmental Health Department, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran; Students Research Committee, Department of Food Sciences and Technology, Faculty of Nutrition and Food Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mohammad Reza Pourmand
- Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Taher Azimi
- Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
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133
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Host-directed kinase inhibitors act as novel therapies against intracellular Staphylococcus aureus. Sci Rep 2019; 9:4876. [PMID: 30890742 PMCID: PMC6425000 DOI: 10.1038/s41598-019-41260-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 03/05/2019] [Indexed: 01/09/2023] Open
Abstract
Host-directed therapeutics are a promising anti-infective strategy against intracellular bacterial pathogens. Repurposing host-targeted drugs approved by the FDA in the US, the MHRA in the UK and/or regulatory equivalents in other countries, is particularly interesting because these drugs are commercially available, safe doses are documented and they have been already approved for other clinical purposes. In this study, we aimed to identify novel therapies against intracellular Staphylococcus aureus, an opportunistic pathogen that is able to exploit host molecular and metabolic pathways to support its own intracellular survival. We screened 133 host-targeting drugs and found three host-directed tyrosine kinase inhibitors (Ibrutinib, Dasatinib and Crizotinib) that substantially impaired intracellular bacterial survival. We found that Ibrutinib significantly increased host cell viability after S. aureus infection via inhibition of cell invasion and intracellular bacterial proliferation. Using phosphoproteomics data, we propose a putative mechanism of action of Ibrutinib involving several host factors, including EPHA2, C-JUN and NWASP. We confirmed the importance of EPHA2 for staphylococcal infection in an EPHA2-knock-out cell line. Our study serves as an important example of feasibility for identifying host-directed therapeutics as candidates for repurposing.
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134
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ADAM10 in Alzheimer's disease: Pharmacological modulation by natural compounds and its role as a peripheral marker. Biomed Pharmacother 2019; 113:108661. [PMID: 30836275 DOI: 10.1016/j.biopha.2019.108661] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Revised: 01/30/2019] [Accepted: 02/01/2019] [Indexed: 12/15/2022] Open
Abstract
Alzheimer's disease (AD) represents a global burden in the economics of healthcare systems. Amyloid-β (Aβ) peptides are formed by amyloid-β precursor protein (AβPP) cleavage, which can be processed by two pathways. The cleavage by the α-secretase A Disintegrin And Metalloprotease 10 (ADAM10) releases the soluble portion (sAβPPα) and prevents senile plaques. This pathway remains largely unknown and ignored, mainly regarding pharmacological approaches that may act via different signaling cascades and thus stimulate non-amyloidogenic cleavage through ADAM10. This review emphasizes the effects of natural compounds on ADAM10 modulation, which eventuates in a neuroprotective mechanism. Moreover, ADAM10 as an AD biomarker is revised. New treatments and preventive interventions targeting ADAM10 regulation for AD are necessary, considering the wide variety of ADAM10 substrates.
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135
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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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136
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Ziesemer S, Möller N, Nitsch A, Müller C, Beule AG, Hildebrandt JP. Sphingomyelin Depletion from Plasma Membranes of Human Airway Epithelial Cells Completely Abrogates the Deleterious Actions of S. aureus Alpha-Toxin. Toxins (Basel) 2019; 11:toxins11020126. [PMID: 30791542 PMCID: PMC6409578 DOI: 10.3390/toxins11020126] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 02/12/2019] [Accepted: 02/15/2019] [Indexed: 12/16/2022] Open
Abstract
Interaction of Staphylococcus aureus alpha-toxin (hemolysin A, Hla) with eukaryotic cell membranes is mediated by proteinaceous receptors and certain lipid domains in host cell plasma membranes. Hla is secreted as a 33 kDa monomer that forms heptameric transmembrane pores whose action compromises maintenance of cell shape and epithelial tightness. It is not exactly known whether certain membrane lipid domains of host cells facilitate adhesion of Ha monomers, oligomerization, or pore formation. We used sphingomyelinase (hemolysin B, Hlb) expressed by some strains of staphylococci to pre-treat airway epithelial model cells in order to specifically decrease the sphingomyelin (SM) abundance in their plasma membranes. Such a pre-incubation exclusively removed SM from the plasma membrane lipid fraction. It abrogated the formation of heptamers and prevented the formation of functional transmembrane pores. Hla exposure of rHlb pre-treated cells did not result in increases in [Ca2+]i, did not induce any microscopically visible changes in cell shape or formation of paracellular gaps, and did not induce hypo-phosphorylation of the actin depolymerizing factor cofilin as usual. Removal of sphingomyelin from the plasma membranes of human airway epithelial cells completely abrogates the deleterious actions of Staphylococcus aureus alpha-toxin.
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Affiliation(s)
- Sabine Ziesemer
- University of Greifswald, Animal Physiology and Biochemistry, Felix Hausdorff-Straße 1, D-17489 Greifswald, Germany.
| | - Nils Möller
- University of Greifswald, Animal Physiology and Biochemistry, Felix Hausdorff-Straße 1, D-17489 Greifswald, Germany.
| | - Andreas Nitsch
- University of Greifswald, Animal Physiology and Biochemistry, Felix Hausdorff-Straße 1, D-17489 Greifswald, Germany.
| | - Christian Müller
- University of Greifswald, Animal Physiology and Biochemistry, Felix Hausdorff-Straße 1, D-17489 Greifswald, Germany.
| | - Achim G Beule
- Department of Otorhinolaryngology, University Hospital, Münster, Germany and Department of Otorhinolaryngology, Head and Neck Surgery, Greifswald University Hospital, D-17489 Greifswald, Germany.
| | - Jan-Peter Hildebrandt
- University of Greifswald, Animal Physiology and Biochemistry, Felix Hausdorff-Straße 1, D-17489 Greifswald, Germany.
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137
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Triplett KD, Pokhrel S, Castleman MJ, Daly SM, Elmore BO, Joyner JA, Sharma G, Herbert G, Campen MJ, Hathaway HJ, Prossnitz ER, Hall PR. GPER activation protects against epithelial barrier disruption by Staphylococcus aureus α-toxin. Sci Rep 2019; 9:1343. [PMID: 30718654 PMCID: PMC6362070 DOI: 10.1038/s41598-018-37951-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2018] [Accepted: 12/07/2018] [Indexed: 02/07/2023] Open
Abstract
Sex bias in innate defense against Staphylococcus aureus skin and soft tissue infection (SSTI) is dependent on both estrogen production by the host and S. aureus secretion of the virulence factor, α-hemolysin (Hla). The impact of estrogen signaling on the immune system is most often studied in terms of the nuclear estrogen receptors ERα and ERβ. However, the potential contribution of the G protein-coupled estrogen receptor (GPER) to innate defense against infectious disease, particularly with respect to skin infection, has not been addressed. Using a murine model of SSTI, we found that GPER activation with the highly selective agonist G-1 limits S. aureus SSTI and Hla-mediated pathogenesis, effects that were absent in GPER knockout mice. Specifically, G-1 reduced Hla-mediated skin lesion formation and pro-inflammatory cytokine production, while increasing bacterial clearance. In vitro, G-1 reduced surface expression of the Hla receptor, ADAM10, in a human keratinocyte cell line and increased resistance to Hla-mediated permeability barrier disruption. This novel role for GPER activation in skin innate defense against infectious disease suggests that G-1 may have clinical utility in patients with epithelial permeability barrier dysfunction or who are otherwise at increased risk of S. aureus infection, including those with atopic dermatitis or cancer.
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Affiliation(s)
- Kathleen D Triplett
- University of New Mexico College of Pharmacy, Department of Pharmaceutical Sciences, Albuquerque, NM, 87131, USA
| | - Srijana Pokhrel
- University of New Mexico College of Pharmacy, Department of Pharmaceutical Sciences, Albuquerque, NM, 87131, USA
| | - Moriah J Castleman
- University of New Mexico College of Pharmacy, Department of Pharmaceutical Sciences, Albuquerque, NM, 87131, USA
| | - Seth M Daly
- University of New Mexico College of Pharmacy, Department of Pharmaceutical Sciences, Albuquerque, NM, 87131, USA
| | - Bradley O Elmore
- University of New Mexico College of Pharmacy, Department of Pharmaceutical Sciences, Albuquerque, NM, 87131, USA
| | - Jason A Joyner
- University of New Mexico College of Pharmacy, Department of Pharmaceutical Sciences, Albuquerque, NM, 87131, USA
| | - Geetanjali Sharma
- University of New Mexico School of Medicine, Department of Internal Medicine, Albuquerque, NM, 87131, USA
| | - Guy Herbert
- University of New Mexico College of Pharmacy, Department of Pharmaceutical Sciences, Albuquerque, NM, 87131, USA
| | - Matthew J Campen
- University of New Mexico College of Pharmacy, Department of Pharmaceutical Sciences, Albuquerque, NM, 87131, USA
| | - Helen J Hathaway
- University of New Mexico School of Medicine, Department of Cell Biology & Physiology, Albuquerque, NM, 87131, USA
| | - Eric R Prossnitz
- University of New Mexico School of Medicine, Department of Internal Medicine, Albuquerque, NM, 87131, USA
| | - Pamela R Hall
- University of New Mexico College of Pharmacy, Department of Pharmaceutical Sciences, Albuquerque, NM, 87131, USA.
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138
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ABL kinase inhibition promotes lung regeneration through expansion of an SCGB1A1+ SPC+ cell population following bacterial pneumonia. Proc Natl Acad Sci U S A 2019; 116:1603-1612. [PMID: 30655340 PMCID: PMC6358689 DOI: 10.1073/pnas.1816030116] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Current therapeutic interventions for the treatment of respiratory infections are hampered by the evolution of multidrug resistance in pathogens as well as the lack of effective cellular targets. Despite the identification of multiple region-specific lung progenitor cells, the identity of molecules that might be therapeutically targeted in response to infections to promote activation of progenitor cell types remains elusive. Here, we report that loss of Abl1 specifically in SCGB1A1-expressing cells leads to a significant increase in the proliferation and differentiation of bronchiolar epithelial cells, resulting in dramatic expansion of an SCGB1A1+ airway cell population that coexpresses SPC, a marker for type II alveolar cells that promotes alveolar regeneration following bacterial pneumonia. Furthermore, treatment with an Abl-specific allosteric inhibitor enhanced regeneration of the alveolar epithelium and promoted accelerated recovery of mice following pneumonia. These data reveal a potential actionable target that may be exploited for efficient recovery after pathogen-induced infections.
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139
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Affiliation(s)
- Lin-Lin Zhou
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica; Chinese Academy of Sciences; Shanghai 201203 China
- University of the Chinese Academy of Sciences; Beijing 100049 China
| | - Cai-Guang Yang
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica; Chinese Academy of Sciences; Shanghai 201203 China
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140
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Buchan KD, Foster SJ, Renshaw SA. Staphylococcus aureus: setting its sights on the human innate immune system. MICROBIOLOGY-SGM 2019; 165:367-385. [PMID: 30625113 DOI: 10.1099/mic.0.000759] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Staphylococcus aureus has colonized humans for at least 10 000 years, and today inhabits roughly a third of the population. In addition, S. aureus is a major pathogen that is responsible for a significant disease burden, ranging in severity from mild skin and soft-tissue infections to life-threatening endocarditis and necrotizing pneumonia, with treatment often hampered by resistance to commonly available antibiotics. Underpinning its versatility as a pathogen is its ability to evade the innate immune system. S. aureus specifically targets innate immunity to establish and sustain infection, utilizing a large repertoire of virulence factors to do so. Using these factors, S. aureus can resist phagosomal killing, impair complement activity, disrupt cytokine signalling and target phagocytes directly using proteolytic enzymes and cytolytic toxins. Although most of these virulence factors are well characterized, their importance during infection is less clear, as many display species-specific activity against humans or against animal hosts, including cows, horses and chickens. Several staphylococcal virulence factors display species specificity for components of the human innate immune system, with as few as two amino acid changes reducing binding affinity by as much as 100-fold. This represents a major issue for studying their roles during infection, which cannot be examined without the use of humanized infection models. This review summarizes the major factors S. aureus uses to impair the innate immune system, and provides an in-depth look into the host specificity of S. aureus and how this problem is being approached.
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Affiliation(s)
- Kyle D Buchan
- 1The Bateson Centre and Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Western Bank, Sheffield S10 2TN, UK
| | - Simon J Foster
- 2Department of Molecular Biology and Biotechnology, University of Sheffield, Western Bank, Sheffield S10 2TN, UK
| | - Stephen A Renshaw
- 1The Bateson Centre and Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Western Bank, Sheffield S10 2TN, UK
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141
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Divyakolu S, Chikkala R, Ratnakar KS, Sritharan V. Hemolysins of <i>Staphylococcus aureus</i>—An Update on Their Biology, Role in Pathogenesis and as Targets for Anti-Virulence Therapy. ACTA ACUST UNITED AC 2019. [DOI: 10.4236/aid.2019.92007] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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142
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Staphylococcus aureus α-Toxin's Close Contacts Ensure the Kill. Trends Microbiol 2018; 27:89-90. [PMID: 30554769 DOI: 10.1016/j.tim.2018.11.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Accepted: 11/29/2018] [Indexed: 11/23/2022]
Abstract
The membrane pore-forming α-toxin is an important virulence factor of Staphylococcus aureus. Target cells can remove pores from their surface, but recent work shows that α-toxin may undermine this self-defense by clinging to epithelial cell junctions. The findings could lead to the development of novel remedies against S. aureus infections.
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143
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Pharmacological Targeting of Pore-Forming Toxins as Adjunctive Therapy for Invasive Bacterial Infection. Toxins (Basel) 2018; 10:toxins10120542. [PMID: 30562923 PMCID: PMC6316385 DOI: 10.3390/toxins10120542] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 12/10/2018] [Accepted: 12/14/2018] [Indexed: 12/23/2022] Open
Abstract
For many of the most important human bacterial infections, invasive disease severity is fueled by the cell damaging and pro-inflammatory effects of secreted pore-forming toxins (PFTs). Isogenic PFT-knockout mutants, e.g., Staphylococcus aureus lacking α-toxin or Streptococcus pneumoniae deficient in pneumolysin, show attenuation in animal infection models. This knowledge has inspired multi-model investigations of strategies to neutralize PFTs or counteract their toxicity as a novel pharmacological approach to ameliorate disease pathogenesis in clinical disease. Promising examples of small molecule, antibody or nanotherapeutic drug candidates that directly bind and neutralize PFTs, block their oligomerization or membrane receptor interactions, plug establishment membrane pores, or boost host cell resiliency to withstand PFT action have emerged. The present review highlights these new concepts, with a special focus on β-PFTs produced by leading invasive human Gram-positive bacterial pathogens. Such anti-virulence therapies could be applied as an adjunctive therapy to antibiotic-sensitive and -resistant strains alike, and further could be free of deleterious effects that deplete the normal microflora.
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144
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Singh V, Phukan UJ. Interaction of host and Staphylococcus aureus protease-system regulates virulence and pathogenicity. Med Microbiol Immunol 2018; 208:585-607. [PMID: 30483863 DOI: 10.1007/s00430-018-0573-y] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 11/22/2018] [Indexed: 02/06/2023]
Abstract
Staphylococcus aureus causes various health care- and community-associated infections as well as certain chronic TH2 driven inflammatory diseases. It is a potent pathogen with serious virulence and associated high morbidity. Severe pathogenicity is accredited to the S. aureus secreted virulence factors such as proteases and host protease modulators. These virulence factors promote adhesion and invasion of bacteria through damage of tight junction barrier and keratinocytes. They inhibit activation and transmigration of various immune cells such as neutrophils (and neutrophil proteases) to evade opsono-phagocytosis and intracellular bacterial killing. Additionally, they protect the bacteria from extracellular killing by disrupting integrity of extracellular matrix. Platelet activation and agglutination is also impaired by these factors. They also block the classical as well as alternative pathways of complement activation and assist in spread of infection through blood and tissue. As these factors are exquisite factors of S. aureus mediated disease development, we have focused on review of diversification of various protease-system associated virulence factors, their structural building, diverse role in disease development and available therapeutic counter measures. This review summarises the role of protease-associated virulence factors during invasion and progression of disease.
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Affiliation(s)
- Vigyasa Singh
- Molecular Bioprospection Department, CSIR-Central Institute of Medicinal and Aromatic Plants, P.O. CIMAP, Lucknow, 226015, India
| | - Ujjal Jyoti Phukan
- School of Life Science, Jawaharlal Nehru University, New Delhi, 110067, India.
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145
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Zhou K, Li C, Chen D, Pan Y, Tao Y, Qu W, Liu Z, Wang X, Xie S. A review on nanosystems as an effective approach against infections of Staphylococcus aureus. Int J Nanomedicine 2018; 13:7333-7347. [PMID: 30519018 PMCID: PMC6233487 DOI: 10.2147/ijn.s169935] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Staphylococcus aureus (S. aureus) is an important zoonotic bacteria and hazardous for the health of human beings and livestock globally. The characteristics like biofilm forming, facultative intracellular survival, and growing resistance of S. aureus pose a great challenge to its use in therapy. Nanoparticles are considered as a promising way to overcome the infections’ therapeutic problems caused by S. aureus. In this paper, the present progress and challenges of nanoparticles in the treatment of S. aureus infection are focused on stepwise. First, the survival and infection mechanism of S. aureus are analyzed. Second, the treatment challenges posed by S. aureus are provided, which is followed by the third step including the advantages of nanoparticles in improving the penetration and accumulation ability of their payload antibiotics into cell, inhibiting S. aureus biofilm formation, and enhancing the antibacterial activity against resistant isolates. Finally, the challenges and future perspective of nanoparticles for S. aureus infection therapy are introduced. This review will help the readers to realize that the nanosystems can effectively fight against the S. aureus infection by inhibiting biofilm formation, enhancing intracellular delivery, and improving activity against methicillin-resistant S. aureus and small colony variant phenotypes as well as aim to help researchers looking for more efficient nano-systems to combat the S. aureus infections.
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Affiliation(s)
- Kaixiang Zhou
- MOA Laboratory for Risk Assessment of Quality and Safety of Livestock and Poultry Products, Huazhong Agricultural University, Wuhan, Hubei, China,
| | - Chao Li
- MOA Laboratory for Risk Assessment of Quality and Safety of Livestock and Poultry Products, Huazhong Agricultural University, Wuhan, Hubei, China,
| | - Dongmei Chen
- National Reference Laboratory of Veterinary Drug Residues (HZAU) and MAO Key Laboratory for Detection of Veterinary Drug Residues, Wuhan, Hubei, China
| | - Yuanhu Pan
- MOA Laboratory for Risk Assessment of Quality and Safety of Livestock and Poultry Products, Huazhong Agricultural University, Wuhan, Hubei, China,
| | - Yanfei Tao
- National Reference Laboratory of Veterinary Drug Residues (HZAU) and MAO Key Laboratory for Detection of Veterinary Drug Residues, Wuhan, Hubei, China
| | - Wei Qu
- National Reference Laboratory of Veterinary Drug Residues (HZAU) and MAO Key Laboratory for Detection of Veterinary Drug Residues, Wuhan, Hubei, China
| | - Zhenli Liu
- National Reference Laboratory of Veterinary Drug Residues (HZAU) and MAO Key Laboratory for Detection of Veterinary Drug Residues, Wuhan, Hubei, China
| | - Xiaofang Wang
- Animal Husbandry and Veterinary Institute of Hebei Province, Baoding, Hebei, China,
| | - Shuyu Xie
- MOA Laboratory for Risk Assessment of Quality and Safety of Livestock and Poultry Products, Huazhong Agricultural University, Wuhan, Hubei, China,
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146
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Mehdizadeh Gohari I, Brefo-Mensah EK, Palmer M, Boerlin P, Prescott JF. Sialic acid facilitates binding and cytotoxic activity of the pore-forming Clostridium perfringens NetF toxin to host cells. PLoS One 2018; 13:e0206815. [PMID: 30403719 PMCID: PMC6221314 DOI: 10.1371/journal.pone.0206815] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 10/20/2018] [Indexed: 11/19/2022] Open
Abstract
NetF-producing type A Clostridium perfringens is an important cause of canine and foal necrotizing enteritis. NetF, related to the β-sheet pore-forming Leukocidin/Hemolysin superfamily, is considered a major virulence factor for this disease. The main purpose of this work is to demonstrate the pore-forming activity of NetF and characterize the chemical nature of its binding site. Electron microscopy using recombinant NetF (rNetF) confirmed that NetF is able to oligomerize and form large pores in equine ovarian (EO) cell membranes and sheep red blood cells. These oligomeric pores appear to be about 4–6 nm in diameter, and the number of oligomer subunits to vary from 6 to 9. Sodium periodate treatment rendered EO cells non-susceptible to NetF, suggesting that NetF binding requires cell surface carbohydrates. NetF cytotoxicity was also inhibited by a lectin that binds sialic acid, by sialidase, and by free sialic acid in excess, all of which clearly implicate sialic acid-containing membrane carbohydrates in NetF binding and/or toxicity for EO cells. Binding of NetF to sheep red blood cells was not inhibited by the gangliosides GM1, GM2 and GM3, nor did the latter promote membrane permeabilization in liposomes, suggesting that they do not constitute the cellular receptors. In contrast, treatment of EO cells with different proteases reduced their susceptibility to NetF, suggesting that the NetF receptor is a sialic acid-containing glycoprotein.
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Affiliation(s)
| | | | - Michael Palmer
- Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada
| | - Patrick Boerlin
- Department of Pathobiology, University of Guelph, Guelph, Ontario, Canada
| | - John F. Prescott
- Department of Pathobiology, University of Guelph, Guelph, Ontario, Canada
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147
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Tan H, Yu Z, Wang C, Zhang Q, Zhao J, Zhang H, Zhai Q, Chen W. Pilot Safety Evaluation of a Novel Strain of Bacteroides ovatus. Front Genet 2018; 9:539. [PMID: 30459813 PMCID: PMC6232662 DOI: 10.3389/fgene.2018.00539] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 10/24/2018] [Indexed: 12/16/2022] Open
Abstract
Bacteroides ovatus ELH-B2 is considered as a potential next-generation probiotic due to its preventive effects on lipopolysaccharides-associated inflammation and intestinal microbiota disorders in mice. To study safety issues associated with B. ovatus ELH-B2, we conducted comprehensive and systematic experiments, including in vitro genetic assessments of potential virulence and antimicrobial resistance genes, and an in vivo acute toxicity study of both immunocompetent and immunosuppressed mice via cyclophosphamide treatment. The results indicated that this novel strain is non-toxigenic, fragilysin is not expressed, and most of potential virulence genes are correlated with cellular structures such as capsular polysaccharide and polysaccharide utilizations. The antibiotic resistance features are unlikely be transferred to other intestinal microorganisms as no plasmids nor related genomic islands were identified. Side effects were not observed in mice. B. ovatus ELH-B2 also alleviated the damages caused by cyclophosphamide injection.
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Affiliation(s)
- Huizi Tan
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China.,School of Food Science and Technology, Jiangnan University, Wuxi, China
| | - Zhiming Yu
- Wuxi People's Hospital Affiliated to Nanjing Medical University, Wuxi, China
| | - Chen Wang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China.,School of Food Science and Technology, Jiangnan University, Wuxi, China
| | - Qingsong Zhang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China.,School of Food Science and Technology, Jiangnan University, Wuxi, China
| | - Jianxin Zhao
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China.,School of Food Science and Technology, Jiangnan University, Wuxi, China
| | - Hao Zhang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China.,School of Food Science and Technology, Jiangnan University, Wuxi, China.,National Engineering Research Center for Functional Food, Jiangnan University, Wuxi, China
| | - Qixiao Zhai
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China.,School of Food Science and Technology, Jiangnan University, Wuxi, China.,International Joint Research Laboratory for Probiotics, Jiangnan University, Wuxi, China
| | - Wei Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China.,School of Food Science and Technology, Jiangnan University, Wuxi, China.,National Engineering Research Center for Functional Food, Jiangnan University, Wuxi, China.,Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Technology and Business University, Beijing, China
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148
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Alanine Scanning Mutagenesis of the MEDI4893 (Suvratoxumab) Epitope Reduces Alpha Toxin Lytic Activity In Vitro and Staphylococcus aureus Fitness in Infection Models. Antimicrob Agents Chemother 2018; 62:AAC.01033-18. [PMID: 30150481 PMCID: PMC6201083 DOI: 10.1128/aac.01033-18] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 08/18/2018] [Indexed: 02/06/2023] Open
Abstract
Alpha toxin (AT) is a cytolytic pore-forming toxin that plays a key role in Staphylococcus aureus pathogenesis; consequently, extensive research was undertaken to understand the AT mechanism of action and its utility as a target for novel prophylaxis and treatment strategies against S. aureus infections. MEDI4893 (suvratoxumab) is a human anti-AT IgG1 monoclonal antibody (MAb) that targets AT and is currently in phase 2 clinical development. Alpha toxin (AT) is a cytolytic pore-forming toxin that plays a key role in Staphylococcus aureus pathogenesis; consequently, extensive research was undertaken to understand the AT mechanism of action and its utility as a target for novel prophylaxis and treatment strategies against S. aureus infections. MEDI4893 (suvratoxumab) is a human anti-AT IgG1 monoclonal antibody (MAb) that targets AT and is currently in phase 2 clinical development. As shown previously, the MEDI4893-binding epitope on AT is comprised of the highly conserved amino acid regions 177 to 200 and 261 to 271, suggesting these amino acids are important for AT function. To test this hypothesis and gain insight into the effect of mutations in the epitope on AT neutralization by MEDI4893, nine MEDI4893 contact residues in AT were individually mutated to alanine. Consistent with our hypothesis, 8 out of 9 mutants exhibited >2-fold loss in lytic activity resulting from a defect in cell binding and pore formation. MEDI4893 binding affinity was reduced >2-fold (2- to 27-fold) for 7 out of 9 mutants, and no binding was detected for the W187A mutant. MEDI4893 effectively neutralized all of the lytic mutants in vitro and in vivo. When the defective mutants were introduced into an S. aureus clinical isolate, the mutant-expressing strains exhibited less severe disease in mouse models and were effectively neutralized by MEDI4893. These results indicate the MEDI4893 epitope is highly conserved due in part to its role in AT pore formation and bacterial fitness, thereby decreasing the likelihood for the emergence of MAb-resistant variants.
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149
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François B, Mercier E, Gonzalez C, Asehnoune K, Nseir S, Fiancette M, Desachy A, Plantefève G, Meziani F, de Lame PA, Laterre PF. Safety and tolerability of a single administration of AR-301, a human monoclonal antibody, in ICU patients with severe pneumonia caused by Staphylococcus aureus: first-in-human trial. Intensive Care Med 2018; 44:1787-1796. [PMID: 30343314 DOI: 10.1007/s00134-018-5229-2] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 05/11/2018] [Indexed: 12/13/2022]
Abstract
PURPOSE Hospital-acquired bacterial pneumonia (HABP) is a critical concern in hospitals with ventilator-associated bacterial pneumonia (VABP) remaining the most common infection in the ICU, often due to Staphylococcus aureus, an increasingly difficult to treat pathogen. Anti-infective monoclonal antibodies (mAb) may provide new, promising treatment options. This randomized, double-blinded, placebo-controlled study aimed at assessing the safety and pharmacokinetics of AR-301, an S. aureus alpha toxin-neutralizing mAb, and exploring its clinical and microbiologic outcomes when used adjunctively with standard-of-care antibiotics. METHODS Eligibility in this trial required microbiologically confirmed severe S. aureus pneumonia, including HABP, VABP or CABP, treated in the ICU and an APACHE II score ≤ 30. Standard-of-care antibiotics selected by the investigators were administered to all patients in the study following clinical and microbiologic confirmation of S. aureus pneumonia. Adjunctive treatment of AR-301 was to start < 36 h after onset of severe pneumonia. AR-301 was administered to four sequentially ascending dose cohorts. The placebo cohort received antibiotics and a placebo buffer. Clinical outcomes were adjudicated by a blinded committee. S. aureus eradication was declared based on a negative follow-up culture and presumed to be negative when no culture was obtained in the presence of clinical improvement. RESULTS Thirteen ICUs enrolled 48 patients, with pneumonia attributable to MRSA in six subjects. The study drug displayed a favorable safety profile: Of 343 AEs reported, 8 (2.3%) were deemed related, none serious. In a post hoc subgroup analysis of VABP patients receiving AR-301, ventilation duration was shorter for AR-301-treated patients compared with the placebo group. Overall, there was a trend toward a better and faster microbiologic eradication at day 28. The PK profile of AR-301 is consistent with that of a human IgG1 mAb, with a plasma half-life of about 25 days. CONCLUSIONS Adjunctive treatment of severe S. aureus HABP with anti-staphylococcal mAbs appears feasible and suggests some clinical benefits, but larger randomized studies are needed to better define its safety and efficacy.
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Affiliation(s)
- Bruno François
- Service de Réanimation Polyvalente, CHU Dupuytren, 2 Avenue Martin Luther King, 87042, Limoges cedex, France. .,Inserm CIC1435, CHU Dupuytren, Limoges, France. .,Inserm, UMR 1092, Faculté de Médecine, Université de Limoges, Limoges, France.
| | | | - Céline Gonzalez
- Service de Réanimation Polyvalente, CHU Dupuytren, 2 Avenue Martin Luther King, 87042, Limoges cedex, France
| | | | - Saad Nseir
- CHU Lille, Centre de Réanimation, Lille University, Medicine School, Lille, France
| | - Maud Fiancette
- Réanimation Polyvalente, CHD Vendée, La Roche-sur-Yon, France
| | - Arnaud Desachy
- Réanimation et Unité de Soins Continus, CH d'Angoulême, Angoulême, France
| | | | - Ferhat Meziani
- Faculté de Médecine, Université de Strasbourg (UNISTRA), Hôpitaux Universitaires de Strasbourg, Service de Réanimation, Nouvel Hôpital Civil, Strasbourg, France.,Inserm, UMR 1260, Regenerative Nanomedicine (RNM), FMTS, Strasbourg, France
| | | | - Pierre-François Laterre
- Service des Soins Intensifs, Cliniques Universitaires Saint-Luc, Université Catholique de Louvain, Brussels, Belgium
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150
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Che R, Ding S, Zhang Q, Yang W, Yan J, Lin X. Haemolysin Sph2 of Leptospira interrogans induces cell apoptosis via intracellular reactive oxygen species elevation and mitochondrial membrane injury. Cell Microbiol 2018; 21:e12959. [PMID: 30278102 DOI: 10.1111/cmi.12959] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Revised: 09/18/2018] [Accepted: 09/19/2018] [Indexed: 12/13/2022]
Abstract
Leptospira interrogans causes widespread leptospirosis in humans and animals, with major symptoms of jaundice and haemorrhage. Sph2, a member of the sphingomyelinase haemolysins, is an important virulence factor for leptospire. In this study, the function and mechanism of Sph2 in the pathogenesis of leptospirosis were investigated to further understand the pathogenesis of leptospire. Real-time PCR analysis of expression levels during cell invasion showed that sph2 gene expression was transiently induced in human umbilical vein endothelial cells (HUVECs), human embryo liver cells (L02), and human epithelial lung cells (L132), with expression levels reaching a peak after 45 min of infection. Further functional analysis of recombinant Sph2 (rSph2) by LDH assays and confocal microscopy showed that rSph2 can be internalised by cells both by causing cell membrane damage and by a damage-independent clathrin-mediated endocytosis pathway. Subsequently, rSph2 is able to translocate to mitochondria, which led to an increase in the levels of reactive oxygen species (ROS) and a decrease of the mitochondrial membrane potential (ΔΨm ). Further flowcytometry analyses after rSph2 exposure showed that 28.7%, 31%, and 27.3% of the HUVEC, L02, and L132 cells, respectively, became apoptotic. Because apoptosis could be decreased with the ROS inhibitor N-acetyl cysteine, these experiments suggested that rSph2 triggers apoptosis through mitochondrial membrane damage and ROS elevation. The ability of leptospiral haemolysin rSph2 to cause apoptosis likely contributes to the pathogenesis of leptospirosis.
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Affiliation(s)
- Rongbo Che
- Department of Medical Microbiology and Parasitology, School of Medicine, Zhejiang University, Hangzhou, China
| | - Shibiao Ding
- Department of Medical Microbiology and Parasitology, School of Medicine, Zhejiang University, Hangzhou, China.,Department of Clinical Laboratory, Hospital of integrated traditional Chinese and Western, Hangzhou, China
| | - Qinchao Zhang
- Department of Medical Microbiology and Parasitology, School of Medicine, Zhejiang University, Hangzhou, China
| | - Weiqun Yang
- Department of Medical Microbiology and Parasitology, School of Medicine, Zhejiang University, Hangzhou, China
| | - Jie Yan
- Department of Medical Microbiology and Parasitology, School of Medicine, Zhejiang University, Hangzhou, China.,Basic Medical Microbiology Division, State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, School of Medicine, Zhejiang University, Hangzhou, China
| | - Xu'ai Lin
- Department of Medical Microbiology and Parasitology, School of Medicine, Zhejiang University, Hangzhou, China.,Basic Medical Microbiology Division, State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, School of Medicine, Zhejiang University, Hangzhou, China
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