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Su MSW, Cheng YL, Lin YS, Wu JJ. Interplay between group A Streptococcus and host innate immune responses. Microbiol Mol Biol Rev 2024; 88:e0005222. [PMID: 38451081 PMCID: PMC10966951 DOI: 10.1128/mmbr.00052-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2024] Open
Abstract
SUMMARYGroup A Streptococcus (GAS), also known as Streptococcus pyogenes, is a clinically well-adapted human pathogen that harbors rich virulence determinants contributing to a broad spectrum of diseases. GAS is capable of invading epithelial, endothelial, and professional phagocytic cells while evading host innate immune responses, including phagocytosis, selective autophagy, light chain 3-associated phagocytosis, and inflammation. However, without a more complete understanding of the different ways invasive GAS infections develop, it is difficult to appreciate how GAS survives and multiplies in host cells that have interactive immune networks. This review article attempts to provide an overview of the behaviors and mechanisms that allow pathogenic GAS to invade cells, along with the strategies that host cells practice to constrain GAS infection. We highlight the counteractions taken by GAS to apply virulence factors such as streptolysin O, nicotinamide-adenine dinucleotidase, and streptococcal pyrogenic exotoxin B as a hindrance to host innate immune responses.
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Affiliation(s)
- Marcia Shu-Wei Su
- Department of Medical Laboratory Science and Biotechnology, College of Medical and Health Sciences, Asia University, Taichung, Taiwan
- Department of Biotechnology and Laboratory Science in Medicine, College of Biomedical Science and Engineering, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Yi-Lin Cheng
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Department of Medical Laboratory Science and Biotechnology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Center of Infectious Disease and Signaling Research, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Yee-Shin Lin
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Center of Infectious Disease and Signaling Research, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Jiunn-Jong Wu
- Department of Medical Laboratory Science and Biotechnology, College of Medical and Health Sciences, Asia University, Taichung, Taiwan
- Department of Biotechnology and Laboratory Science in Medicine, College of Biomedical Science and Engineering, National Yang Ming Chiao Tung University, Taipei, Taiwan
- Department of Medical Research, China Medical University Hospital, China Medical University, Taichung, Taiwan
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Meng M, Wang J, Li H, Wang J, Wang X, Li M, Gao X, Li W, Ma C, Wei L. Eliminating the invading extracellular and intracellular FnBp + bacteria from respiratory epithelial cells by autophagy mediated through FnBp-Fn-Integrin α5β1 axis. Front Cell Infect Microbiol 2024; 13:1324727. [PMID: 38264727 PMCID: PMC10803403 DOI: 10.3389/fcimb.2023.1324727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 12/18/2023] [Indexed: 01/25/2024] Open
Abstract
Background We previously found that the respiratory epithelial cells could eliminate the invaded group A streptococcus (GAS) through autophagy induced by binding a fibronectin (Fn) binding protein (FnBp) expressed on the surface of GAS to plasma protein Fn and its receptor integrin α5β1 of epithelial cells. Is autophagy initiated by FnBp+ bacteria via FnBp-Fn-Integrin α5β1 axis a common event in respiratory epithelial cells? Methods We chose Staphylococcus aureus (S. aureus/S. a) and Listeria monocytogenes (L. monocytogenes/L. m) as representatives of extracellular and intracellular FnBp+ bacteria, respectively. The FnBp of them was purified and the protein function was confirmed by western blot, viable bacteria count, confocal and pull-down. The key molecule downstream of the action axis was detected by IP, mass spectrometry and bio-informatics analysis. Results We found that different FnBp from both S. aureus and L. monocytogenes could initiate autophagy through FnBp-Fn-integrin α5β1 axis and this could be considered a universal event, by which host tries to remove invading bacteria from epithelial cells. Importantly, we firstly reported that S100A8, as a key molecule downstream of integrin β1 chain, is highly expressed upon activation of integrin α5β1, which in turn up-regulates autophagy. Conclusions Various FnBp from FnBp+ bacteria have the ability to initiate autophagy via FnBp-Fn-Integrin α5β1 axis to promote the removal of invading bacteria from epithelial cells in the presence of fewer invaders. S100A8 is a key molecule downstream of Integrin α5β1 in this autophagy pathway.
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Affiliation(s)
- Meiqi Meng
- Department of Immunology, Key Laboratory of Immune Mechanism and Intervention on Serious Disease in Hebei, Hebei Medical University, Shijiazhuang, China
| | - Jiachao Wang
- Department of Immunology, Key Laboratory of Immune Mechanism and Intervention on Serious Disease in Hebei, Hebei Medical University, Shijiazhuang, China
| | - Hongru Li
- Department of Immunology, Key Laboratory of Immune Mechanism and Intervention on Serious Disease in Hebei, Hebei Medical University, Shijiazhuang, China
| | - Jiao Wang
- Department of Immunology, Key Laboratory of Immune Mechanism and Intervention on Serious Disease in Hebei, Hebei Medical University, Shijiazhuang, China
| | - Xuan Wang
- Department of Immunology, Key Laboratory of Immune Mechanism and Intervention on Serious Disease in Hebei, Hebei Medical University, Shijiazhuang, China
- Clinical Laboratory, the Second Hospital of Hebei Medical University, Hebei Key Laboratory of Laboratory Medicine, Shijiazhuang, China
| | - Miao Li
- Department of Immunology, Key Laboratory of Immune Mechanism and Intervention on Serious Disease in Hebei, Hebei Medical University, Shijiazhuang, China
| | - Xue Gao
- Department of Immunology, Key Laboratory of Immune Mechanism and Intervention on Serious Disease in Hebei, Hebei Medical University, Shijiazhuang, China
| | - Wenjian Li
- Department of Immunology, Key Laboratory of Immune Mechanism and Intervention on Serious Disease in Hebei, Hebei Medical University, Shijiazhuang, China
| | - Cuiqing Ma
- Department of Immunology, Key Laboratory of Immune Mechanism and Intervention on Serious Disease in Hebei, Hebei Medical University, Shijiazhuang, China
| | - Lin Wei
- Department of Immunology, Key Laboratory of Immune Mechanism and Intervention on Serious Disease in Hebei, Hebei Medical University, Shijiazhuang, China
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Fibronectin and Its Role in Human Infective Diseases. Cells 2019; 8:cells8121516. [PMID: 31779172 PMCID: PMC6952806 DOI: 10.3390/cells8121516] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 11/19/2019] [Accepted: 11/22/2019] [Indexed: 01/25/2023] Open
Abstract
Fibronectin is a multidomain glycoprotein ubiquitously detected in extracellular fluids and matrices of a variety of animal and human tissues where it functions as a key link between matrices and cells. Fibronectin has also emerged as the target for a large number of microorganisms, particularly bacteria. There are clear indications that the binding of microorganism’ receptors to fibronectin promotes attachment to and infection of host cells. Each bacterium may use different receptors which recognize specific fibronectin domains, mostly the N-terminal domain and the central cell-binding domain. In many cases, fibronectin receptors have actions over and above that of simple adhesion: In fact, adhesion is often the prerequisite for invasion and internalization of microorganisms in the cells of colonized tissues. This review updates the current understanding of fibronectin receptors of several microorganisms with emphasis on their biochemical and structural properties and the role they can play in the onset and progression of host infection diseases. Furthermore, we describe the antigenic profile and discuss the possibility of designing adhesion inhibitors based on the structure of the fibronectin-binding site in the receptor or the receptor-binding site in fibronectin.
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Abstract
The main strategies used by pathogenic bacteria to infect eukaryotic tissue include their adherence to cells and the extracellular matrix (ECM), the subsequent colonization and invasion as well as the evasion of immune defences. A variety of structurally and functionally characterized adhesins and binding proteins of gram-positive bacteria facilitate these processes by specifically recognizing and interacting with various components of the host ECM, including different collagens, fibronectin and other macromolecules. The ECM affects the cellular physiology of our body and is critical for adhesion, migration, proliferation, and differentiation of many host cell types, but also provides the support for infiltrating pathogens, particularly under conditions of injury and trauma. Moreover, microbial binding to a variety of adhesive components in host tissue fluids leads to structural and/or functional alterations of host proteins and to the activation of cellular mechanisms that influence tissue and cell invasion of pathogens. Since the diverse interactions of gram-positive bacteria with the ECM represent important pathogenicity mechanisms, their characterization not only allows a better understanding of microbial invasion but also provides clues for the design of novel therapeutic strategies to manage infectious diseases.
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Arato V, Gasperini G, Giusti F, Ferlenghi I, Scarselli M, Leuzzi R. Dual role of the colonization factor CD2831 in Clostridium difficile pathogenesis. Sci Rep 2019; 9:5554. [PMID: 30944377 PMCID: PMC6447587 DOI: 10.1038/s41598-019-42000-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 03/12/2019] [Indexed: 01/01/2023] Open
Abstract
Clostridium difficile is a Gram-positive, anaerobic bacterium and the leading cause of antibiotic-associated diarrhea and pseudomembranous colitis. C. difficile modulates its transition from a motile to a sessile lifestyle through a mechanism of riboswitches regulated by cyclic diguanosine monophosphate (c-di-GMP). Previously described as a sortase substrate positively regulated by c-di-GMP, CD2831 was predicted to be a collagen-binding protein and thus potentially involved in sessility. By overexpressing CD2831 in C. difficile and heterologously expressing it on the surface of Lactococcus lactis, here we further demonstrated that CD2831 is a collagen-binding protein, able to bind to immobilized collagen types I, III and V as well as native collagen produced by human fibroblasts. We also observed that the overexpression of CD2831 raises the ability to form biofilm on abiotic surface in both C. difficile and L. lactis. Notably, we showed that CD2831 binds to the collagen-like domain of the human complement component C1q, suggesting a role in preventing complement cascade activation via the classical pathway. This functional characterization places CD2831 in the Microbial Surface Components Recognizing Adhesive Matrix Molecule (MSCRAMMs) family, a class of virulence factors with a dual role in adhesion to collagen-rich tissues and in host immune evasion by binding to human complement components.
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Affiliation(s)
- Vanessa Arato
- Glaxo Smith Kline Vaccines, Via Fiorentina 1, 53100, Siena, Italy.,University of Padova, Department of Biomedical Sciences, 35131, Padua, Italy
| | - Gianmarco Gasperini
- GSK Vaccines Institute for Global Health (GVGH), Via Fiorentina 1, 53100, Siena, Italy
| | - Fabiola Giusti
- Glaxo Smith Kline Vaccines, Via Fiorentina 1, 53100, Siena, Italy
| | - Ilaria Ferlenghi
- Glaxo Smith Kline Vaccines, Via Fiorentina 1, 53100, Siena, Italy
| | - Maria Scarselli
- Glaxo Smith Kline Vaccines, Via Fiorentina 1, 53100, Siena, Italy
| | - Rosanna Leuzzi
- Glaxo Smith Kline Vaccines, Via Fiorentina 1, 53100, Siena, Italy.
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Streptococcus pyogenes CAMP factor promotes bacterial adhesion and invasion in pharyngeal epithelial cells without serum via PI3K/Akt signaling pathway. Microbes Infect 2017; 20:9-18. [PMID: 28951316 DOI: 10.1016/j.micinf.2017.09.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 09/14/2017] [Accepted: 09/16/2017] [Indexed: 12/18/2022]
Abstract
Streptococcus pyogenes is a bacterium that causes systemic diseases, such as pharyngitis and toxic shock syndrome, via oral- or nasal-cavity infection. S. pyogenes produces various molecules known to function with serum components that lead to bacterial adhesion and invasion in human tissues. In this study, we identified a novel S. pyogenes adhesin/invasin. Our results revealed that CAMP factor promoted streptococcal adhesion and invasion in pharyngeal epithelial Detroit562 cells without serum. Recombinant CAMP factor initially localized on the membranes of cells and then became internalized in the cytosol following S. pyogenes infection. Additionally, CAMP factor phosphorylated phosphoinositide 3-kinase and serine-threonine kinase in the cells. ELISA results demonstrate that CAMP factor affected the amount of phosphorylated phosphoinositide 3-kinase and serine-threonine kinase in Detroit562 cells. Furthermore, CAMP factor did not reverse the effect of phosphoinositide 3-kinase knockdown by small interfering RNA in reducing the level of adhesion and invasion of S. pyogenes isogenic cfa-deficient mutant. These results suggested that S. pyogenes CAMP factor activated the phosphoinositide 3-kinase/serine-threonine kinase signaling pathway, promoting S. pyogenes invasion of Detroit562 cells without serum. Our findings suggested that CAMP factor played an important role on adhesion and invasion in pharyngeal epithelial cells.
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Kanwal S, Jensch I, Palm GJ, Brönstrup M, Rohde M, Kohler TP, Somplatzki D, Tegge W, Jenkinson HF, Hammerschmidt S. Mapping the recognition domains of pneumococcal fibronectin-binding proteins PavA and PavB demonstrates a common pattern of molecular interactions with fibronectin type III repeats. Mol Microbiol 2017; 105:839-859. [PMID: 28657670 DOI: 10.1111/mmi.13740] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/22/2017] [Indexed: 11/29/2022]
Abstract
Colonization of mucosal respiratory surfaces is a prerequisite for the human pathobiont Streptococcus pneumoniae (the pneumococcus) to cause severe invasive infections. The arsenal of pneumococcal adhesins interacts with a multitude of extracellular matrix proteins. A paradigm for pneumococci is their interaction with the adhesive glycoprotein fibronectin, which facilitates bacterial adherence to host cells. Here, we deciphered the molecular interaction between fibronectin and pneumococcal fibronectin-binding proteins (FnBPs) PavA and PavB respectively. We show in adherence and binding studies that the pneumococcal interaction with fibronectin is a non-human specific trait. PavA and PavB target at least 13 out of 15 type III fibronectin domains as demonstrated in ligand overlay assays, surface plasmon resonance studies and SPOT peptide arrays. Strikingly, both pneumococcal FnBPs recognize similar peptides in targeted type III repeats. Structural comparisons revealed that the targeted type III repeat epitopes cluster on the inner strands of both β-sheets forming the fibronectin domains. Importantly, synthetic peptides of FnIII1 , FnIII5 or FnIII15 bind directly to FnBPs PavA and PavB respectively. In conclusion, our study suggests a common pattern of molecular interactions between pneumococcal FnBPs and fibronectin. The specific epitopes recognized in this study can potentially be tested as antimicrobial targets in further scientific endeavours.
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Affiliation(s)
- Sajida Kanwal
- Department Genetics of Microorganisms, Interfaculty Institute for Genetics and Functional Genomics, University of Greifswald, Greifswald, D-17487, Germany
| | - Inga Jensch
- Department Genetics of Microorganisms, Interfaculty Institute for Genetics and Functional Genomics, University of Greifswald, Greifswald, D-17487, Germany
| | - Gottfried J Palm
- Department of Structural Biology, Institute for Biochemistry, University of Greifswald, Greifswald, D-17487, Germany
| | - Mark Brönstrup
- Department of Chemical Biology, Helmholtz Centre for Infection Research and German Centre for Infection Research (DZIF), Braunschweig, D-38124, Germany
| | - Manfred Rohde
- Central Facility for Microscopy, ZEIM, Helmholtz Centre for Infection Research, Braunschweig, D-38124, Germany
| | - Thomas P Kohler
- Department Genetics of Microorganisms, Interfaculty Institute for Genetics and Functional Genomics, University of Greifswald, Greifswald, D-17487, Germany
| | - Daniela Somplatzki
- Research Center for Infectious Diseases, University of Würzburg, Würzburg, D-97070, Germany
| | - Werner Tegge
- Department of Chemical Biology, Helmholtz Centre for Infection Research and German Centre for Infection Research (DZIF), Braunschweig, D-38124, Germany
| | - Howard F Jenkinson
- Department of Oral and Dental Science, University of Bristol, Bristol, UK
| | - Sven Hammerschmidt
- Department Genetics of Microorganisms, Interfaculty Institute for Genetics and Functional Genomics, University of Greifswald, Greifswald, D-17487, Germany.,Research Center for Infectious Diseases, University of Würzburg, Würzburg, D-97070, Germany
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Oppegaard O, Mylvaganam H, Skrede S, Jordal S, Glambek M, Kittang BR. Clinical and molecular characteristics of infective β-hemolytic streptococcal endocarditis. Diagn Microbiol Infect Dis 2017; 89:135-142. [PMID: 28780243 DOI: 10.1016/j.diagmicrobio.2017.06.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 06/15/2017] [Accepted: 06/23/2017] [Indexed: 10/19/2022]
Abstract
Streptococcus pyogenes (S. pyogenes) and Streptococcus dysgalactiae subspecies equisimilis (SDSE) cause considerable morbidity and mortality, and show similarities in disease manifestations and pathogenic mechanisms. Their involvement in infective endocarditis, however, has not been well described. Invasive S. pyogenes and SDSE infections in Health Region Bergen, Norway, in the period 1999-2013 were reviewed, and sixteen cases of endocarditis were identified. The median duration of symptoms was 2.5days, the frequency of embolic events 50%, 38% received valve replacement and the 30-day mortality was 25%. In S. pyogenes, a significant correlation was observed between the repertoire of fibronectin-binding genes, phenotypic binding ability to fibronectin and disease manifestations. Conversely, no associations between phenotypic and genotypic characteristics were detected in SDSE. S. pyogenes and SDSE endocarditis is characterized by rapid and severe clinical manifestations. The pathogenesis is multifactorial, but our results infer a potential role of fibronectin binding in the development of S. pyogenes endocarditis.
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Affiliation(s)
- Oddvar Oppegaard
- Department of Medicine, Haukeland University Hospital, Bergen, Norway; Department of Clinical Science, University of Bergen, Bergen, Norway.
| | - Haima Mylvaganam
- Department of Microbiology, Haukeland University Hospital, Bergen, Norway.
| | - Steinar Skrede
- Department of Medicine, Haukeland University Hospital, Bergen, Norway; Department of Clinical Science, University of Bergen, Bergen, Norway.
| | - Stina Jordal
- Department of Medicine, Haukeland University Hospital, Bergen, Norway.
| | - Marte Glambek
- Department of Medicine, Haraldsplass Deaconess Hospital, Bergen, Norway.
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Nakajima S, Aikawa C, Nozawa T, Minowa-Nozawa A, Toh H, Nakagawa I. Bcl-xL Affects Group A Streptococcus-Induced Autophagy Directly, by Inhibiting Fusion between Autophagosomes and Lysosomes, and Indirectly, by Inhibiting Bacterial Internalization via Interaction with Beclin 1-UVRAG. PLoS One 2017; 12:e0170138. [PMID: 28085926 PMCID: PMC5235370 DOI: 10.1371/journal.pone.0170138] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 12/29/2016] [Indexed: 11/19/2022] Open
Abstract
Anti-apoptotic Bcl-2 and Bcl-xL are proposed to regulate starvation-induced autophagy by directly interacting with Beclin 1. Beclin 1 is also thought to be involved in multiple vesicle trafficking pathways such as endocytosis by binding to Atg14L and UVRAG. However, how the interaction of Bcl-2 family proteins and Beclin 1 regulates anti-bacterial autophagy (xenophagy) is still unclear. In this study, we analyzed these interactions using Group A Streptococcus (GAS; Streptococcus pyogenes) infection as a model. GAS is internalized into epithelial cells through endocytosis, while the intracellular fate of GAS is degradation by autophagy. Here, we found that Bcl-xL but not Bcl-2 regulates GAS-induced autophagy. Autophagosome-lysosome fusion and the internalization process during GAS infection were promoted in Bcl-xL knockout cells. In addition, knockout of Beclin 1 phenocopied the internalization defect of GAS. Furthermore, UVRAG interacts not only with Beclin 1 but also with Bcl-xL, and overexpression of UVRAG partially rescued the internalization defect of Beclin 1 knockout cells during GAS infection. Thus, our results indicate that Bcl-xL inhibits GAS-induced autophagy directly by suppressing autophagosome-lysosome fusion and indirectly by suppressing GAS internalization via interaction with Beclin 1-UVRAG.
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Affiliation(s)
- Shintaro Nakajima
- Department of Microbiology, Graduate School of Medicine, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto, Japan
| | - Chihiro Aikawa
- Department of Microbiology, Graduate School of Medicine, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto, Japan
| | - Takashi Nozawa
- Department of Microbiology, Graduate School of Medicine, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto, Japan
| | - Atsuko Minowa-Nozawa
- Department of Microbiology, Graduate School of Medicine, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto, Japan
| | - Hirotaka Toh
- Department of Microbiology, Graduate School of Medicine, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto, Japan
| | - Ichiro Nakagawa
- Department of Microbiology, Graduate School of Medicine, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto, Japan
- * E-mail:
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Brouwer S, Barnett TC, Rivera-Hernandez T, Rohde M, Walker MJ. Streptococcus pyogenes adhesion and colonization. FEBS Lett 2016; 590:3739-3757. [PMID: 27312939 DOI: 10.1002/1873-3468.12254] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 06/10/2016] [Accepted: 06/13/2016] [Indexed: 12/19/2022]
Abstract
Streptococcus pyogenes (group A Streptococcus, GAS) is a human-adapted pathogen responsible for a wide spectrum of disease. GAS can cause relatively mild illnesses, such as strep throat or impetigo, and less frequent but severe life-threatening diseases such as necrotizing fasciitis and streptococcal toxic shock syndrome. GAS is an important public health problem causing significant morbidity and mortality worldwide. The main route of GAS transmission between humans is through close or direct physical contact, and particularly via respiratory droplets. The upper respiratory tract and skin are major reservoirs for GAS infections. The ability of GAS to establish an infection in the new host at these anatomical sites primarily results from two distinct physiological processes, namely bacterial adhesion and colonization. These fundamental aspects of pathogenesis rely upon a variety of GAS virulence factors, which are usually under strict transcriptional regulation. Considerable progress has been made in better understanding these initial infection steps. This review summarizes our current knowledge of the molecular mechanisms of GAS adhesion and colonization.
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Affiliation(s)
- Stephan Brouwer
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Australia
| | - Timothy C Barnett
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Australia
| | - Tania Rivera-Hernandez
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Australia
| | - Manfred Rohde
- Central Facility for Microscopy, Helmholtz Centre For Infection Research, Braunschweig, Germany
| | - Mark J Walker
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Australia
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The FasX Small Regulatory RNA Negatively Regulates the Expression of Two Fibronectin-Binding Proteins in Group A Streptococcus. J Bacteriol 2015; 197:3720-30. [PMID: 26391206 DOI: 10.1128/jb.00530-15] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 09/12/2015] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED The group A Streptococcus (GAS; Streptococcus pyogenes) causes more than 700 million human infections each year. The success of this pathogen can be traced in part to the extensive arsenal of virulence factors that are available for expression in temporally and spatially specific manners. To modify the expression of these virulence factors, GAS use both protein- and RNA-based regulators, with the best-characterized RNA-based regulator being the small regulatory RNA (sRNA) FasX. FasX is a 205-nucleotide sRNA that contributes to GAS virulence by enhancing the expression of the thrombolytic secreted virulence factor streptokinase and by repressing the expression of the collagen-binding cell surface pili. Here, we have expanded the FasX regulon, showing that this sRNA also negatively regulates the expression of the adhesion- and internalization-promoting, fibronectin-binding proteins PrtF1 and PrtF2. FasX posttranscriptionally regulates the expression of PrtF1/2 through a mechanism that involves base pairing to the prtF1 and prtF2 mRNAs within their 5' untranslated regions, overlapping the mRNA ribosome-binding sites. Thus, duplex formation between FasX and the prtF1 and prtF2 mRNAs blocks ribosome access, leading to an inhibition of mRNA translation. Given that FasX positively regulates the expression of the spreading factor streptokinase and negatively regulates the expression of the collagen-binding pili and of the fibronectin-binding PrtF1/2, our data are consistent with FasX functioning as a molecular switch that governs the transition of GAS between the colonization and dissemination stages of infection. IMPORTANCE More than half a million deaths each year are a consequence of infections caused by GAS. Insights into how this pathogen regulates the production of proteins during infection may facilitate the development of novel therapeutic or preventative regimens aimed at inhibiting this activity. Here, we have expanded insight into the regulatory activity of the GAS small RNA FasX. In addition to identifying that FasX reduces the abundance of the cell surface-located fibronectin-binding proteins PrtF1/2, fibronectin is present in high abundance in human tissues, and we have determined the mechanism behind this regulation. Importantly, as FasX is the only mechanistically characterized regulatory RNA in GAS, it serves as a model RNA in this and related pathogens.
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Ma W, Ma H, Mosher DF. On-Off Kinetics of Engagement of FNI Modules of Soluble Fibronectin by β-Strand Addition. PLoS One 2015; 10:e0124941. [PMID: 25919138 PMCID: PMC4412574 DOI: 10.1371/journal.pone.0124941] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 03/20/2015] [Indexed: 02/07/2023] Open
Abstract
Intrinsically disordered sequences within bacterial adhesins bind to E-strands in the β-sheets of multiple FNI modules of fibronectin (FN) by anti-parallel β-strand addition, also called tandem β-zipper formation. The FUD segment of SfbI of Streptococcus pyogenes and Bbk32 segment of BBK32 of Borrelia burgdorferi, despite being imbedded in different adhesins from different bacteria, target the same 2-5,8-9 FNI modules, 2-5,8-9 FNI, in the N-terminal 70-kDa region (FN70K) of FN. To facilitate further comparisons, FUD, Bbk32, two other polypeptides based on SfbI that target 1-5 FNI (HADD) and 2-5 FNI (FRD), and mutant Bbk32 (ΔBbk32) were produced with fluorochromes placed just outside of the binding sequences. Unlabeled FUD competed ~ 1000-fold better for binding of labeled Bbk32 to FN than unlabeled Bbk32 competed for binding of labeled FUD to FN. Binding kinetics were determined by fluorescence polarization in a stopped-flow apparatus. On-rates for FUD, Bbk32, HADD, and FRD were similar, and all bound more rapidly to FN70K fragment than to full length FN. In stopped-flow displacement and size exclusion chromatographic assays, however, k off for FUD or HADD to FN70K or FN was considerably lower compared to k off of FRD or Bbk32. FUD and Bbk32 differ in the spacing between sequences that interact with 3FNI and 4FNI or with 5FNI and 8FNI. ΔBbk32, in which 2 residues were removed from Bbk32 to make the spacing more like FUD, had a k off intermediate between that of Bbk32 and FUD. These results indicate a "folding-after-binding" process after initial association of certain polypeptide sequences to FN that results in formation of a stable complex and is a function of number of FNI modules engaged by the polypeptide, spacing of engagement sites, and perhaps flexibility within the polypeptide-FN complex. We suggest that contributions of SfbI and BBK32 adhesins to bacterial pathogenicity may be determined in part by stability of adhesin-FN complexes.
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Affiliation(s)
- Wenjiang Ma
- Departments of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Hanqing Ma
- Departments of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Deane F. Mosher
- Departments of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- * E-mail:
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Buscetta M, Papasergi S, Firon A, Pietrocola G, Biondo C, Mancuso G, Midiri A, Romeo L, Teti G, Speziale P, Trieu-Cuot P, Beninati C. FbsC, a novel fibrinogen-binding protein, promotes Streptococcus agalactiae-host cell interactions. J Biol Chem 2015; 289:21003-21015. [PMID: 24904056 DOI: 10.1074/jbc.m114.553073] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Streptococcus agalactiae (group B Streptococcus or GBS) is a common cause of invasive infections in newborn infants and adults. The ability of GBS to bind human fibrinogen is of crucial importance in promoting colonization and invasion of host barriers. We characterized here a novel fibrinogen-binding protein of GBS, designated FbsC (Gbs0791), which is encoded by the prototype GBS strain NEM316. FbsC, which bears two bacterial immunoglobulin-like tandem repeat domains and a C-terminal cell wall-anchoring motif (LPXTG), was found to be covalently linked to the cell wall by the housekeeping sortase A. Studies using recombinant FbsC indicated that it binds fibrinogen in a dose-dependent and saturable manner, and with moderate affinity. Expression of FbsC was detected in all clinical GBS isolates, except those belonging to the hypervirulent lineage ST17. Deletion of fbsC decreases NEM316 abilities to adhere to and invade human epithelial and endothelial cells, and to form biofilm in vitro. Notably, bacterial adhesion to fibrinogen and fibrinogen binding to bacterial cells were abolished following fbsC deletion in NEM316. Moreover, the virulence of the fbsC deletion mutant and its ability to colonize the brain were impaired in murine models of infection. Finally, immunization with recombinant FbsC significantly protected mice from lethal GBS challenge. In conclusion, FbsC is a novel fibrinogen-binding protein expressed by most GBS isolates that functions as a virulence factor by promoting invasion of epithelial and endothelial barriers. In addition, the protein has significant immunoprotective activity and may be a useful component of an anti-GBS vaccine.
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Ma W, Ma H, Fogerty FJ, Mosher DF. Bivalent ligation of the collagen-binding modules of fibronectin by SFS, a non-anchored bacterial protein of Streptococcus equi. J Biol Chem 2014; 290:4866-4876. [PMID: 25525266 DOI: 10.1074/jbc.m114.612259] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
SFS is a non-anchored protein of Streptococcus equi subspecies equi that causes upper respiratory infection in horses. SFS has been shown to bind to fibronectin (FN) and block interaction of FN with type I collagen. We have characterized interactions of a recombinant 60-mer polypeptide, R1R2, with FN. R1R2 contains two copies of collagen-like 19-residue repeats. Experiments utilizing various FN fragments and epitope-mapped anti-FN monoclonal antibodies located the binding site to (8-9)FNI modules of the gelatin-binding domain. Fluorescence polarization and competitive enzyme-linked assays demonstrated that R1R2 binds preferentially to compact dimeric FN rather than monomeric constructs containing (8-9)FNI or a large dimeric FN construct that is constitutively in an extended conformation. In contrast to bacterial peptides that bind (2-5)FNI in addition to (8-9)FNI, R1R2 did not cause conformational extension of FN as assessed by a conformationally sensitive antibody. Equilibrium and stopped-flow binding assays and size exclusion chromatography were compatible with a two-step binding reaction in which each of the repeats of R1R2 interacts with one of the subunits of dimeric FN, resulting in a stable complex with a slow koff. In addition to not binding to type I collagen, the R1R2·FN complex incorporated less efficiently into extracellular matrix than free FN. Thus, R1R2 binds to FN utilizing features of compact soluble FN and in doing so interferes with the organization of the extracellular matrix. A similar bivalent binding strategy may underlie the collagen-FN interaction.
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Affiliation(s)
- Wenjiang Ma
- Departments of Biomolecular Chemistry and Medicine, University of Wisconsin, Madison, Wisconsin 53706
| | - Hanqing Ma
- Departments of Biomolecular Chemistry and Medicine, University of Wisconsin, Madison, Wisconsin 53706
| | - Frances J Fogerty
- Departments of Biomolecular Chemistry and Medicine, University of Wisconsin, Madison, Wisconsin 53706
| | - Deane F Mosher
- Departments of Biomolecular Chemistry and Medicine, University of Wisconsin, Madison, Wisconsin 53706.
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15
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Tiouajni M, Durand D, Blondeau K, Graille M, Urvoas A, Valerio-Lepiniec M, Guellouz A, Aumont-Nicaise M, Minard P, van Tilbeurgh H. Structural and functional analysis of the fibronectin-binding protein FNE from Streptococcus equi spp. equi. FEBS J 2014; 281:5513-31. [PMID: 25290767 DOI: 10.1111/febs.13092] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Revised: 09/24/2014] [Accepted: 09/30/2014] [Indexed: 12/17/2022]
Abstract
Streptococcus equi is a horse pathogen belonging to Lancefield group C. Infection by S. equi ssp. equi causes strangles, a serious and highly contagious disease of the upper respiratory tract. S. equi ssp. equi secretes a fibronectin (Fn)-binding protein, FNE, that does not contain cell wall-anchoring motifs. FNE binds to the gelatin-binding domain (GBD) of Fn, composed of the motifs (6) FI (12) FII (789) FI . FNE lacks the canonical Fn-binding peptide repeats observed in many microbial surface components recognizing adhesive matrix molecules. We found that the interaction between FNE and the human GBD is mediated by the binding of the disordered C-terminal region (residues 208-262) of FNE to the (789) FI GBD subfragment. The crystal structure of FNE showed that it is similar to the minor pilus protein Spy0125 of Streptococcus pyogenes, found at the end of pilus polymers and responsible for adhesion. FNE and Spy0125 both have a superimposable internal thioester bond between highly conserved Cys and Gln residues. Small-angle X-ray scattering of the FNE-(789) FI complex provided a model that aligns the C-terminal peptide of FNE with the E-strands of the FI domains, adopting the β-zipper extension model observed in previous structures of microbial surface components recognizing adhesive matrix molecule adhesion peptides bound to FI domains.
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Affiliation(s)
- Mounira Tiouajni
- Institut de Biochimie et de Biophysique Moléculaire et Cellulaire, UMR 8619 CNRS, Université Paris Sud, Orsay, France
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16
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Harris G, Ma W, Maurer LM, Potts JR, Mosher DF. Borrelia burgdorferi protein BBK32 binds to soluble fibronectin via the N-terminal 70-kDa region, causing fibronectin to undergo conformational extension. J Biol Chem 2014; 289:22490-9. [PMID: 24962582 DOI: 10.1074/jbc.m114.578419] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
BBK32 is a fibronectin (FN)-binding protein expressed on the cell surface of Borrelia burgdorferi, the causative agent of Lyme disease. There is conflicting information about where and how BBK32 interacts with FN. We have characterized interactions of a recombinant 86-mer polypeptide, "Bbk32," comprising the unstructured FN-binding region of BBK32. Competitive enzyme-linked assays utilizing various FN fragments and epitope-mapped anti-FN monoclonal antibodies showed that Bbk32 binding involves both the fibrin-binding and the gelatin-binding domains of the 70-kDa N-terminal region (FN70K). Crystallographic and NMR analyses of smaller Bbk32 peptides complexed, respectively, with (2-3)FNI and (8-9)FNI, demonstrated that binding occurs by β-strand addition. Isothermal titration calorimetry indicated that Bbk32 binds to isolated FN70K more tightly than to intact FN. In a competitive enzyme-linked binding assay, complex formation with Bbk32 enhanced binding of FN with mAbIII-10 to the (10)FNIII module. Thus, Bbk32 binds to multiple FN type 1 modules of the FN70K region by a tandem β-zipper mechanism, and in doing so increases accessibility of FNIII modules that interact with other ligands. The similarity in the FN-binding mechanism of BBK32 and previously studied streptococcal proteins suggests that the binding and associated conformational change of FN play a role in infection.
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Affiliation(s)
- Gemma Harris
- From the Department of Biology, University of York, York YO10 5DD, United Kingdom and
| | - Wenjiang Ma
- the Departments of Biomolecular Chemistry and Medicine, University of Wisconsin, Madison, Wisconsin 53706
| | - Lisa M Maurer
- the Departments of Biomolecular Chemistry and Medicine, University of Wisconsin, Madison, Wisconsin 53706
| | - Jennifer R Potts
- From the Department of Biology, University of York, York YO10 5DD, United Kingdom and
| | - Deane F Mosher
- the Departments of Biomolecular Chemistry and Medicine, University of Wisconsin, Madison, Wisconsin 53706
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17
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Sagar V, Bergmann R, Nerlich A, McMillan DJ, Nitsche-Schmitz DP, Fulde M, Talay S, Geffers R, Hoe N, Kumar R, Rohde M, Chakraborti A, Chhatwal GS. Differences in virulence repertoire and cell invasive potential of group A Streptococcus emm1-2 in comparison to emm1 genotype. Int J Med Microbiol 2014; 304:685-95. [PMID: 24856243 DOI: 10.1016/j.ijmm.2014.04.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Revised: 04/24/2014] [Accepted: 04/27/2014] [Indexed: 11/26/2022] Open
Abstract
Group A streptococcus (GAS, Streptococcus pyogenes) type emm1 is widely associated with streptococcal invasive disease. This type is prevalent worldwide but is rare in India. Instead, emm1-2 type which is closely related to emm1 but is a distinct type is more prevalent. Although emm1 has been well characterized, information available on emm1-2 is rare. In this study we present a comparative study of both types. DNA microarray analysis showed segregation of emm1 and emm1-2 isolates into two distinct clusters. Out of 229 arrayed genes, 83-87% were present, 6-9% absent and 4-8% genes were ambiguous in emm1 isolates. emm1-2 strains harboured only 68-77%, 11-13% were absent and 10-20% ambiguous genes. Fourteen genes, present in all emm1, were completely absent in the emm1-2 isolates. sfb1 is a gene which encodes for Streptococcal fibronectin binding adhesin and invasin which has restricted distribution among different emm types of GAS. A variant of sfb1 (sfb1-2) was the only gene which was present in all emm1-2 isolates, but absent from all emm1 strains. Sfb1 and Sfb1-2 differ in sequences in the aromatic domain and the proline rich repeat region, whereas the fibronectin binding region was conserved and exhibited similar fibronectin binding activity. The presence of Sfb1-2 in emm1-2 strains was concomitant with significantly higher fibronectin-binding and invasion efficiency of HEp-2 cells when compared to emm1 isolates. The role of Sfb1-2 in invasion was confirmed by latex bead assay. emm1-2 isolates follow membrane ruffling mechanism during invasion and intracellularly follow classical endocytic pathway. Further studies are required to understand the correlation between the presence of emm1-2 isolates and the disease pattern in North India.
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Affiliation(s)
- Vivek Sagar
- Helmholtz Centre for Infection Research, Braunschweig, Germany; Postgraduate Institute of Medical Education and Research, Chandigarh, India.
| | - Rene Bergmann
- Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Andreas Nerlich
- Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - David J McMillan
- Bacterial Pathogenesis Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Australia and Inflammation and Healing Research Cluster, School of Health and Sport Sciences, University of the Sunshine Coast, Sippy Downs, Australia
| | | | - Marcus Fulde
- Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Susanne Talay
- Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Robert Geffers
- Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Nancy Hoe
- National Institute of Health, Hamilton, USA
| | - Rajesh Kumar
- Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Manfred Rohde
- Helmholtz Centre for Infection Research, Braunschweig, Germany
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18
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Disease manifestations and pathogenic mechanisms of Group A Streptococcus. Clin Microbiol Rev 2014. [PMID: 24696436 DOI: 10.1128/cmr.00101-13)] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Streptococcus pyogenes, also known as group A Streptococcus (GAS), causes mild human infections such as pharyngitis and impetigo and serious infections such as necrotizing fasciitis and streptococcal toxic shock syndrome. Furthermore, repeated GAS infections may trigger autoimmune diseases, including acute poststreptococcal glomerulonephritis, acute rheumatic fever, and rheumatic heart disease. Combined, these diseases account for over half a million deaths per year globally. Genomic and molecular analyses have now characterized a large number of GAS virulence determinants, many of which exhibit overlap and redundancy in the processes of adhesion and colonization, innate immune resistance, and the capacity to facilitate tissue barrier degradation and spread within the human host. This improved understanding of the contribution of individual virulence determinants to the disease process has led to the formulation of models of GAS disease progression, which may lead to better treatment and intervention strategies. While GAS remains sensitive to all penicillins and cephalosporins, rising resistance to other antibiotics used in disease treatment is an increasing worldwide concern. Several GAS vaccine formulations that elicit protective immunity in animal models have shown promise in nonhuman primate and early-stage human trials. The development of a safe and efficacious commercial human vaccine for the prophylaxis of GAS disease remains a high priority.
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19
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Walker MJ, Barnett TC, McArthur JD, Cole JN, Gillen CM, Henningham A, Sriprakash KS, Sanderson-Smith ML, Nizet V. Disease manifestations and pathogenic mechanisms of Group A Streptococcus. Clin Microbiol Rev 2014; 27:264-301. [PMID: 24696436 PMCID: PMC3993104 DOI: 10.1128/cmr.00101-13] [Citation(s) in RCA: 550] [Impact Index Per Article: 55.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Streptococcus pyogenes, also known as group A Streptococcus (GAS), causes mild human infections such as pharyngitis and impetigo and serious infections such as necrotizing fasciitis and streptococcal toxic shock syndrome. Furthermore, repeated GAS infections may trigger autoimmune diseases, including acute poststreptococcal glomerulonephritis, acute rheumatic fever, and rheumatic heart disease. Combined, these diseases account for over half a million deaths per year globally. Genomic and molecular analyses have now characterized a large number of GAS virulence determinants, many of which exhibit overlap and redundancy in the processes of adhesion and colonization, innate immune resistance, and the capacity to facilitate tissue barrier degradation and spread within the human host. This improved understanding of the contribution of individual virulence determinants to the disease process has led to the formulation of models of GAS disease progression, which may lead to better treatment and intervention strategies. While GAS remains sensitive to all penicillins and cephalosporins, rising resistance to other antibiotics used in disease treatment is an increasing worldwide concern. Several GAS vaccine formulations that elicit protective immunity in animal models have shown promise in nonhuman primate and early-stage human trials. The development of a safe and efficacious commercial human vaccine for the prophylaxis of GAS disease remains a high priority.
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Affiliation(s)
- Mark J. Walker
- School of Chemistry and Molecular Biosciences and the Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, QLD, Australia
| | - Timothy C. Barnett
- School of Chemistry and Molecular Biosciences and the Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, QLD, Australia
| | - Jason D. McArthur
- School of Biological Sciences and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
| | - Jason N. Cole
- School of Chemistry and Molecular Biosciences and the Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, QLD, Australia
- Department of Pediatrics and Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California, USA
| | - Christine M. Gillen
- School of Chemistry and Molecular Biosciences and the Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, QLD, Australia
| | - Anna Henningham
- School of Chemistry and Molecular Biosciences and the Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, QLD, Australia
- Department of Pediatrics and Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California, USA
| | - K. S. Sriprakash
- QIMR Berghofer Medical Research Institute, Herston, Brisbane, QLD, Australia
| | - Martina L. Sanderson-Smith
- School of Biological Sciences and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
| | - Victor Nizet
- Department of Pediatrics and Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California, USA
- Rady Children's Hospital, San Diego, California, USA
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20
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Georgousakis MM, McMillan DJ, Batzloff MR, Sriprakash KS. Moving forward: a mucosal vaccine against group A streptococcus. Expert Rev Vaccines 2014; 8:747-60. [DOI: 10.1586/erv.09.33] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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21
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The fibronectin-binding motif within FlpA facilitates Campylobacter jejuni adherence to host cell and activation of host cell signaling. Emerg Microbes Infect 2013; 2:e65. [PMID: 26038437 PMCID: PMC3826066 DOI: 10.1038/emi.2013.65] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Revised: 08/02/2013] [Accepted: 08/05/2013] [Indexed: 11/12/2022]
Abstract
Campylobacter jejuni is a gram-negative, curved and rod-shaped bacterium that causes human gastroenteritis. Acute disease is associated with C. jejuni invasion of the intestinal epithelium. Epithelial cells infected with C. jejuni strains containing mutations in the FlpA and CadF fibronectin (Fn)-binding proteins exhibit reduced invasion of host cells and a C. jejuni CadF FlpA double mutant is impaired in the activation of epidermal growth factor receptor (EGFR) and Rho GTPase Rac1. Although these observations establish a role for Fn-binding proteins during C. jejuni invasion, their mechanistic contributions to invasion-associated signaling are unclear. We examined FlpA, a C. jejuni Fn-binding protein composed of three FNIII-like repeats D1, D2 and D3, to identify the interactions required for cellular adherence on pathogen-induced host cell signaling. We report that FlpA binds the Fn gelatin-binding domain via a motif within the D2 repeat. Epithelial cells infected with a flpA mutant exhibited decreased Rac1 activation and reduced membrane ruffling that coincided with impaired delivery of the secreted Cia proteins and reduced cell association. Phosphorylation of the Erk1/2 kinase, a downstream effector of EGFR signaling, was specifically associated with FlpA-mediated activation of β1-integrin and EGFR signaling. In vivo experiments revealed that FlpA is necessary for C. jejuni disease based on bacterial dissemination to the spleen of IL-10−/− germ-free mice. Thus, a novel Fn-binding motif within FlpA potentiates activation of Erk1/2 signaling via β1-integrin during C. jejuni infection.
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22
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Matthews JM, Potts JR. The tandem β-zipper: Modular binding of tandem domains and linear motifs. FEBS Lett 2013; 587:1164-71. [DOI: 10.1016/j.febslet.2013.01.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2012] [Revised: 01/07/2013] [Accepted: 01/07/2013] [Indexed: 11/17/2022]
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23
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Variability in the distribution of genes encoding virulence factors and putative extracellular proteins of Streptococcus pyogenes in India, a region with high streptococcal disease burden, and implication for development of a regional multisubunit vaccine. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2012; 19:1818-25. [PMID: 22971782 DOI: 10.1128/cvi.00112-12] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Streptococcus pyogenes causes a wide variety of human diseases and is a significant cause of morbidity and mortality. Attempts to develop a vaccine were hampered by the genetic diversity of S. pyogenes across different regions of the world. This study sought to identify streptococcal antigens suitable for a region-specific vaccine in India. We used a two-step approach, first performing epidemiological analysis to identify the conserved antigens among Indian isolates. The second step consisted of validating the identified antigens by serological analysis. The 201 streptococcal clinical isolates from India used in this study represented 69 different emm types, with emm12 being the most prevalent. Virulence profiling of the North and South Indian S. pyogenes isolates with a custom-designed streptococcal virulence microarray identified seven conserved putative vaccine candidates. Collagen-like surface protein (SCI), putative secreted 5'-nucleotidase (PSNT), and C5a peptidase were found in 100% of the isolates, while R28, a putative surface antigen (PSA), and a hypothetical protein (HYP) were found in 90% of the isolates. A fibronectin binding protein, SfbI, was present in only 78% of the isolates. In order to validate the identified potential vaccine candidates, 185 serum samples obtained from patients with different clinical manifestations were tested for antibodies. Irrespective of clinical manifestations, serum samples showed high antibody titers to all proteins except for SCI and R28. Thus, the data indicate that PSNT, C5a peptidase, PSA, HYP, and SfbI are promising candidates for a region-specific streptococcal vaccine for the different parts of India.
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Abstract
Although the incidence of acute rheumatic fever and rheumatic heart disease has decreased significantly in regions of the world where antibiotics are easily accessible, there remains a high incidence in developing nations as well as in certain regions where there is a high incidence of genetic susceptibility. These diseases are a function of poverty, low socioeconomic status, and barriers to healthcare access, and it is in the developing world that a comprehensive prevention program is most critically needed. Development of group A streptococcal vaccines has been under investigation since the 1960s and 50 years later, we still have no vaccine. Factors that contribute to this lack of success include a potential risk for developing vaccine-induced rheumatic heart disease, as well as difficulties in covering the many serological subtypes of M protein, a virulence factor found on the surface of the bacterium. Yet, development of a successful vaccine program for prevention of group A streptococcal infection still offers the best chance for eradication of rheumatic fever in the twenty-first century. Other useful approaches include continuation of primary and secondary prevention with antibiotics and implementation of health care policies that provide patients with easy access to antibiotics. Improved living conditions and better hygiene are also critical to the prevention of the spread of group A streptococcus, especially in impoverished regions of the world. The purpose of this article is to discuss current and recent developments in the diagnosis, pathogenesis, and management of rheumatic fever and rheumatic heart disease.
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Affiliation(s)
- Christopher Chang
- Division of Allergy, Asthma and Immunology, Thomas Jefferson University, Nemours/A.I. Dupont Children's Hospital, 1600 Rockland Road, Wilmington, DE 19803, USA.
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25
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Rohde M, Chhatwal GS. Adherence and invasion of streptococci to eukaryotic cells and their role in disease pathogenesis. Curr Top Microbiol Immunol 2012. [PMID: 23203001 DOI: 10.1007/82_2012_281] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Streptococcal adhesion, invasion, intracellular trafficking, dissemination, and persistence in eukaryotic cells have a variety of implications in the infection pathogenesis. While cell adhesion establishes the initial host contact, adhering bacteria exploit the host cell for their own benefit. Internalization into the host cell is an essential step for bacterial survival and subsequent dissemination and persistence, thus playing a key role in the course of infection. This chapter summarizes the current knowledge about the diverse mechanisms of streptococcal adhesion to and invasion into different eukaryotic cells and the impact on dissemination and persistence which is reflected by consequences for the pathogenesis of streptococcal infections.
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Affiliation(s)
- Manfred Rohde
- Department of Medical Microbiology, Helmholtz Centre for Infection Research, Braunschweig, Germany.
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26
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Popova TG, Millis B, Bailey C, Popov SG. Platelets, inflammatory cells, von Willebrand factor, syndecan-1, fibrin, fibronectin, and bacteria co-localize in the liver thrombi of Bacillus anthracis-infected mice. Microb Pathog 2011; 52:1-9. [PMID: 22001909 DOI: 10.1016/j.micpath.2011.08.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2010] [Revised: 08/16/2011] [Accepted: 08/23/2011] [Indexed: 11/27/2022]
Abstract
UNLABELLED Vascular dysfunction and thrombosis have been described in association with anthrax infection in humans and animals but the mechanisms of these dysfunctions, as well as the components involved in thrombi formation are poorly understood. Immunofluorescent microscopy was used to define the composition of thrombi in the liver of mice challenged with the Bacillus anthracis Sterne spores. Lethal infection with the toxigenic Sterne strain, in contrast to the non-lethal, non-toxigenic delta-Sterne strain, demonstrated time-dependent increase in the number of vegetative bacteria inside the liver sinusoids and central vein. Massive appearance of thrombi typically occluding the lumen of the vessels coincided with the sudden death of infected animals. Bacterial chains in the thrombi were stained positive for syndecan-1 (SDC-1), fibronectin, and were surrounded by fibrin polymers, GPIIb-positive platelets, von Willebrand Factor (vWF), CD45-positive leukocytes, and massive amount of shed SDC-1. Experiments with human umbilical vein endothelial cells (HUVECs) demonstrated the active role of the host response to the secreted pathogenic factors of bacteria during the onset of the pro-thrombotic condition. The bacterial culture supernatants, as well as the isolated proteins (the pore-forming toxin anthrolysin O and phospholipase C) induced release of vWF, while anthrolysin O, sphingomyelinase and edema toxin induced release of thrombin from HUVECs and polymerization of fibrin in the presence of human plasma. CONCLUSION Our findings suggest that activation of endothelium in response to infection can contribute to the formation of occlusive thrombi consisting of aggregated bacteria, vWF, shed SDC-1, fibrin, activated platelets, fibronectin and leukocytes.
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Affiliation(s)
- Taissia G Popova
- National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, VA 20110, USA.
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27
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Amelung S, Nerlich A, Rohde M, Spellerberg B, Cole JN, Nizet V, Chhatwal GS, Talay SR. The FbaB-type fibronectin-binding protein of Streptococcus pyogenes promotes specific invasion into endothelial cells. Cell Microbiol 2011; 13:1200-11. [PMID: 21615663 DOI: 10.1111/j.1462-5822.2011.01610.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Invasive serotype M3 Streptococcus pyogenes are among the most frequently isolated organisms from patients suffering from invasive streptococcal disease and have the potential to invade primary human endothelial cells (EC) via a rapid and efficient mechanism. FbaB protein, the fibronectin-binding protein expressed by M3 S. pyogenes, was herein identified as a potent invasin for EC. By combining heterologous gene expression with allelic replacement, we demonstrate that FbaB is essential and sufficient to trigger EC invasion via a Rac1-dependent phagocytosis-like uptake. FbaB-mediated uptake follows the classical endocytic pathway with lysosomal destination. FbaB is demonstrated to be a streptococcal invasin exhibiting EC tropism. FbaB thus initiates a process that may contribute to the deep tissue tropism and spread of invasive S. pyogenes isolates into the vascular EC lining.
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Affiliation(s)
- Silva Amelung
- Department of Medical Microbiology, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany
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28
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SCM, a novel M-like protein from Streptococcus canis, binds (mini)-plasminogen with high affinity and facilitates bacterial transmigration. Biochem J 2011; 434:523-35. [PMID: 21210764 DOI: 10.1042/bj20101121] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Streptococcus canis is an important zoonotic pathogen capable of causing serious invasive diseases in domestic animals and humans. In the present paper we report the binding of human plasminogen to S. canis and the recruitment of proteolytically active plasmin on its surface. The binding receptor for plasminogen was identified as a novel M-like protein designated SCM (S. canis M-like protein). SPR (surface plasmon resonance) analyses, radioactive dot-blot analyses and heterologous expression on the surface of Streptococcus gordonii confirmed the plasminogen-binding capability of SCM. The binding domain was located within the N-terminus of SCM, which specifically bound to the C-terminal part of plasminogen (mini-plasminogen) comprising kringle domain 5 and the catalytic domain. In the presence of urokinase, SCM mediated plasminogen activation on the bacterial surface that was inhibited by serine protease inhibitors and lysine amino acid analogues. Surface-bound plasmin effectively degraded purified fibrinogen as well as fibrin clots, resulting in the dissolution of fibrin thrombi. Electron microscopic illustration and time-lapse imaging demonstrated bacterial transmigration through fibrinous thrombi. The present study has led, for the first time, to the identification of SCM as a novel receptor for (mini)-plasminogen mediating the fibrinolytic activity of S. canis.
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Marjenberg ZR, Ellis IR, Hagan RM, Prabhakaran S, Höök M, Talay SR, Potts JR, Staunton D, Schwarz-Linek U. Cooperative binding and activation of fibronectin by a bacterial surface protein. J Biol Chem 2011; 286:1884-94. [PMID: 21059652 PMCID: PMC3023484 DOI: 10.1074/jbc.m110.183053] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2010] [Revised: 11/03/2010] [Indexed: 11/06/2022] Open
Abstract
Integrin-dependent cell invasion of some pathogenic bacteria is mediated by surface proteins targeting the extracellular matrix protein fibronectin (FN). Although the structural basis for bacterial FN recognition is well understood, it has been unclear why proteins such as streptococcal SfbI contain several FN-binding sites. We used microcalorimetry to reveal cooperative binding of FN fragments to arrays of binding sites in SfbI. In combination with thermodynamic analyses, functional cell-based assays show that SfbI induces conformational changes in the N-terminal 100-kDa region of FN (FN100kDa), most likely by competition with intramolecular interactions defining an inactive state of FN100kDa. This study provides insights into how long range conformational changes resulting in FN activation may be triggered by bacterial pathogens.
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Affiliation(s)
- Zoe R. Marjenberg
- From the Biomedical Sciences Research Complex, University of St. Andrews, St. Andrews KY16 9ST, Scotland, United Kingdom
| | - Ian R. Ellis
- the Unit of Cell and Molecular Biology, Dental School, University of Dundee, Dundee DD1 4HR, Scotland, United Kingdom
| | - Robert M. Hagan
- From the Biomedical Sciences Research Complex, University of St. Andrews, St. Andrews KY16 9ST, Scotland, United Kingdom
| | - Sabitha Prabhakaran
- the Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M University Health Science Center, Houston, Texas 77030
| | - Magnus Höök
- the Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M University Health Science Center, Houston, Texas 77030
| | - Susanne R. Talay
- the Department of Microbial Pathogenesis, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany
| | - Jennifer R. Potts
- the Department of Biology and Department of Chemistry, University of York, York YO10 5YW, United Kingdom, and
| | - David Staunton
- the Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
| | - Ulrich Schwarz-Linek
- From the Biomedical Sciences Research Complex, University of St. Andrews, St. Andrews KY16 9ST, Scotland, United Kingdom
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Henderson B, Nair S, Pallas J, Williams MA. Fibronectin: a multidomain host adhesin targeted by bacterial fibronectin-binding proteins. FEMS Microbiol Rev 2011; 35:147-200. [DOI: 10.1111/j.1574-6976.2010.00243.x] [Citation(s) in RCA: 227] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
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Maurer LM, Tomasini-Johansson BR, Ma W, Annis DS, Eickstaedt NL, Ensenberger MG, Satyshur KA, Mosher DF. Extended binding site on fibronectin for the functional upstream domain of protein F1 of Streptococcus pyogenes. J Biol Chem 2010; 285:41087-99. [PMID: 20947497 PMCID: PMC3003407 DOI: 10.1074/jbc.m110.153692] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2010] [Revised: 09/23/2010] [Indexed: 01/14/2023] Open
Abstract
The 49-residue functional upstream domain (FUD) of Streptococcus pyogenes F1 adhesin interacts with fibronectin (FN) in a heretofore unknown manner that prevents assembly of a FN matrix. Biotinylated FUD (b-FUD) bound to adsorbed FN or its recombinant N-terminal 70-kDa fibrin- and gelatin-binding fragment (70K). Binding was blocked by FN or 70K, but not by fibrin- or gelatin-binding subfragments of 70K. Isothermal titration calorimetry showed that FUD binds with K(d) values of 5.2 and 59 nM to soluble 70K and FN, respectively. We tested sets of FUD mutants and epitope-mapped monoclonal antibodies (mAbs) for ability to compete with b-FUD for binding to FN or to block FN assembly by cultured fibroblasts. Deletions or alanine substitutions throughout FUD caused loss of both activities. mAb 4D1 to the (2)FNI module had little effect, whereas mAb 7D5 to the (4)FNI module in the fibrin-binding region, 5C3 to the (9)FNI module in the gelatin-binding region, or L8 to the G-strand of (1)FNIII module adjacent to (9)FNI caused loss of binding of b-FUD to FN and decreased FN assembly. Conversely, FUD blocked binding of 7D5, 5C3, or L8, but not of 4D1, to FN. Circular dichroism indicated that FUD binds to 70K by β-strand addition, a possibility supported by modeling based on crystal structures of peptides bound to (2)FNI-(5)FNI of the fibrin-binding domain and (8)FNI-(9)FNI of the gelatin-binding domain. Thus, the interaction likely involves an extensive anti-parallel β-zipper in which FUD interacts with the E-strands of (2)FNI-(5)FNI and (8)FNI-(9)FNI.
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Affiliation(s)
- Lisa M. Maurer
- From the Departments of Biomolecular Chemistry and Medicine, University of Wisconsin, Madison, Wisconsin 53706
| | | | - Wenjiang Ma
- From the Departments of Biomolecular Chemistry and Medicine, University of Wisconsin, Madison, Wisconsin 53706
| | - Douglas S. Annis
- From the Departments of Biomolecular Chemistry and Medicine, University of Wisconsin, Madison, Wisconsin 53706
| | - Nathan L. Eickstaedt
- From the Departments of Biomolecular Chemistry and Medicine, University of Wisconsin, Madison, Wisconsin 53706
| | - Martin G. Ensenberger
- From the Departments of Biomolecular Chemistry and Medicine, University of Wisconsin, Madison, Wisconsin 53706
| | - Kenneth A. Satyshur
- From the Departments of Biomolecular Chemistry and Medicine, University of Wisconsin, Madison, Wisconsin 53706
| | - Deane F. Mosher
- From the Departments of Biomolecular Chemistry and Medicine, University of Wisconsin, Madison, Wisconsin 53706
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Rohde M, Graham RM, Branitzki-Heinemann K, Borchers P, Preuss C, Schleicher I, Zähner D, Talay SR, Fulde M, Dinkla K, Chhatwal GS. Differences in the aromatic domain of homologous streptococcal fibronectin-binding proteins trigger different cell invasion mechanisms and survival rates. Cell Microbiol 2010; 13:450-68. [PMID: 21054741 DOI: 10.1111/j.1462-5822.2010.01547.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Group A streptococci (GAS, Streptococcus pyogenes) and Group G streptococci (GGS, Streptococcus dysgalactiae ssp. equisimilis) adhere to and invade host cells by binding to fibronectin. The fibronectin-binding protein SfbI from GAS acts as an invasin by using a caveolae-mediated mechanism. In the present study we have identified a fibronectin-binding protein, GfbA, from GGS, which functions as an adhesin and invasin. Although there is a high degree of similarity in the C-terminal sequence of SfbI and GfbA, the invasion mechanisms are different. Unlike caveolae-mediated invasion by SfbI-expressing GAS, the GfbA-expressing GGS isolate trigger cytoskeleton rearrangements. Heterologous expression of GfbA on the surface of a commensal Streptococcus gordonii and purified recombinant protein also triggered actin rearrangements. Expression of a truncated GfbA (lacking the aromatic domain) and chimeric GfbA/SfbI protein (replacing the aromatic domain of SfbI with the GfbA aromatic domain) on S. gordonii or recombinant proteins alone showed that the aromatic domain of GfbA is responsible for different invasion mechanisms. This is the first evidence for a biological function of the aromatic domain of fibronectin-binding proteins. Furthermore, we show that streptococci invading via cytoskeleton rearrangements and intracellular trafficking along the classical endocytic pathway are less persistence than streptococci entering via caveolae.
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Affiliation(s)
- Manfred Rohde
- Helmholtz Centre for Infection Research, Department of Medical Microbiology, Braunschweig, Germany.
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Hoffmann C, Berking A, Agerer F, Buntru A, Neske F, Chhatwal GS, Ohlsen K, Hauck CR. Caveolin limits membrane microdomain mobility and integrin-mediated uptake of fibronectin-binding pathogens. J Cell Sci 2010; 123:4280-91. [PMID: 21098633 DOI: 10.1242/jcs.064006] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Staphylococcus aureus, which is a leading cause of hospital-acquired infections, binds via fibronectin to integrin α5β1, a process that can promote host colonization in vivo. Integrin engagement induces actin cytoskeleton rearrangements that result in the uptake of S. aureus by non-professional phagocytic cells. Interestingly, we found that fibronectin-binding S. aureus trigger the redistribution of membrane microdomain components. In particular, ganglioside GM1 and GPI-linked proteins were recruited upon integrin β1 engagement, and disruption of membrane microdomains blocked bacterial internalization. Several membrane-microdomain-associated proteins, such as flotillin-1 and flotillin-2, as well as caveolin, were recruited to sites of bacterial attachment. Whereas dominant-negative versions of flotillin-2 did not affect bacterial attachment or internalization, cells deficient for caveolin-1 (Cav1(-/-)) showed increased uptake of S. aureus and other Fn-binding pathogens. Recruitment of membrane microdomains to cell-associated bacteria was unaltered in Cav1(-/-) cells. However, fluorescence recovery after photobleaching (FRAP) revealed an enhanced mobility of membrane-microdomain-associated proteins in the absence of caveolin-1. Enhanced membrane microdomain mobility and increased uptake of S. aureus was repressed by expression of wild-type caveolin-1, but not caveolin-1 G83S, which harbors a point mutation in the caveolin scaffolding domain. Similarly, chemical or physical stimulation of membrane fluidity led to increased uptake of S. aureus. These results highlight a crucial role for caveolin-1 in negative regulation of membrane microdomain mobility, thereby affecting endocytosis of bacteria-engaged integrins. This process might not only limit host cell invasion by integrin-binding bacterial pathogens, but might also be physiologically relevant for integrin-mediated cell adhesion.
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Affiliation(s)
- Christine Hoffmann
- Lehrstuhl Zellbiologie X908, Universität Konstanz, Universitätsstr. 10, 78457 Konstanz, Germany
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Provenza G, Provenzano M, Visai L, Burke FM, Geoghegan JA, Stravalaci M, Gobbi M, Mazzini G, Arciola CR, Foster TJ, Speziale P. Functional analysis of a murine monoclonal antibody against the repetitive region of the fibronectin-binding adhesins fibronectin-binding protein A and fibronectin-binding protein B from Staphylococcus aureus. FEBS J 2010; 277:4490-505. [DOI: 10.1111/j.1742-4658.2010.07835.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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35
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Atkin KE, Brentnall AS, Harris G, Bingham RJ, Erat MC, Millard CJ, Schwarz-Linek U, Staunton D, Vakonakis I, Campbell ID, Potts JR. The streptococcal binding site in the gelatin-binding domain of fibronectin is consistent with a non-linear arrangement of modules. J Biol Chem 2010; 285:36977-83. [PMID: 20843804 PMCID: PMC2978626 DOI: 10.1074/jbc.m110.156935] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Fibronectin-binding proteins (FnBPs) of Staphylococcus aureus and Streptococcus pyogenes mediate invasion of human endothelial and epithelial cells in a process likely to aid the persistence and/or dissemination of infection. In addition to binding sites for the N-terminal domain (NTD) of fibronectin (Fn), a number of streptococcal FnBPs also contain an upstream region (UR) that is closely associated with an NTD-binding region; UR binds to the adjacent gelatin-binding domain (GBD) of Fn. Previously, UR was shown to be required for efficient streptococcal invasion of epithelial cells. Here we show, using a Streptococcus zooepidemicus FnBP, that the UR-binding site in GBD resides largely in the (8)F1(9)F1 module pair. We also show that UR inhibits binding of a peptide from the α1 chain of type I collagen to (8)F1(9)F1 and that UR binding to (8)F1 is likely to occur through anti-parallel β-zipper formation. Thus, we propose that streptococcal proteins that contain adjacent NTD- and GBD-binding sites form a highly unusual extended tandem β-zipper that spans the two domains and mediates high affinity binding to Fn through a large intermolecular interface. The proximity of the UR- and NTD-binding sequences in streptococcal FnBPs is consistent with a non-linear arrangement of modules in the tertiary structure of the GBD of Fn.
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Affiliation(s)
- Kate E Atkin
- Department of Biology, University of York, Heslington, York, YO10 5DD, United Kingdom
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36
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Deutscher AT, Jenkins C, Minion FC, Seymour LM, Padula MP, Dixon NE, Walker MJ, Djordjevic SP. Repeat regions R1 and R2 in the P97 paralogue Mhp271 of Mycoplasma hyopneumoniae bind heparin, fibronectin and porcine cilia. Mol Microbiol 2010; 78:444-58. [DOI: 10.1111/j.1365-2958.2010.07345.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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The structure and function of serum opacity factor: a unique streptococcal virulence determinant that targets high-density lipoproteins. J Biomed Biotechnol 2010; 2010:956071. [PMID: 20671930 PMCID: PMC2910554 DOI: 10.1155/2010/956071] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2010] [Accepted: 05/26/2010] [Indexed: 12/04/2022] Open
Abstract
Serum opacity factor (SOF) is a virulence determinant expressed by a variety of streptococcal and staphylococcal species including both human and animal pathogens. SOF derives its name from its ability to opacify serum where it targets and disrupts the structure of high-density lipoproteins resulting in formation of large lipid vesicles that cause the serum to become cloudy. SOF is a multifunctional protein and in addition to its opacification activity, it binds to a number of host proteins that mediate adhesion of streptococci to host cells, and it plays a role in resistance to phagocytosis in human blood. This article will provide an overview of the structure and function of SOF, its role in the pathogenesis of streptococcal infections, its vaccine potential, its prevalence and distribution in bacteria, and the molecular mechanism whereby SOF opacifies serum and how an understanding of this mechanism may lead to therapies for reducing high-cholesterol concentrations in blood, a major risk factor for cardiovascular disease.
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Kaur SJ, Nerlich A, Bergmann S, Rohde M, Fulde M, Zähner D, Hanski E, Zinkernagel A, Nizet V, Chhatwal GS, Talay SR. The CXC chemokine-degrading protease SpyCep of Streptococcus pyogenes promotes its uptake into endothelial cells. J Biol Chem 2010; 285:27798-805. [PMID: 20562101 DOI: 10.1074/jbc.m109.098053] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Streptococcus pyogenes expresses the LPXTG motif-containing cell envelope serine protease SpyCep (also called ScpC, PrtS) that degrades and inactivates the major chemoattractant interleukin 8 (IL-8), thereby impairing host neutrophil recruitment. In this study, we identified a novel function of SpyCep: the ability to mediate uptake into primary human endothelial cells. SpyCep triggered its uptake into endothelial cells but not into human epithelial cells originating from pharynx or lung, indicating an endothelial cell-specific uptake mechanism. SpyCep mediated cellular invasion by an endosomal/lysosomal pathway distinct from the caveolae-mediated invasion pathway of S. pyogenes. Recombinant expression and purification of proteolytically active SpyCep and a series of subfragments allowed functional dissection of the domains responsible for endothelial cell invasion and IL-8 degradation. The N-terminal PR domain was sufficient to mediate endothelial cell invasion, whereas for IL-8-degrading activity, the protease domain and the flanking A domain were required. A polyclonal rabbit serum raised against the recombinant protease efficiently blocked the invasion-mediating activity of SpyCep but not its proteolytic function, further indicating that SpyCep-mediated internalization is independent from its enzymatic activity. SpyCep may thus specifically mediate its own uptake as secreted protein into human endothelial cells.
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Affiliation(s)
- Simran Jeet Kaur
- Department of Microbial Pathogenesis, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, D-38124 Braunschweig, Germany
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Structural optimisation of a conformational epitope improves antigenicity when expressed as a recombinant fusion protein. Vaccine 2009; 27:6799-806. [DOI: 10.1016/j.vaccine.2009.08.049] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2009] [Revised: 08/11/2009] [Accepted: 08/14/2009] [Indexed: 11/21/2022]
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Nobbs AH, Lamont RJ, Jenkinson HF. Streptococcus adherence and colonization. Microbiol Mol Biol Rev 2009; 73:407-50, Table of Contents. [PMID: 19721085 PMCID: PMC2738137 DOI: 10.1128/mmbr.00014-09] [Citation(s) in RCA: 425] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Streptococci readily colonize mucosal tissues in the nasopharynx; the respiratory, gastrointestinal, and genitourinary tracts; and the skin. Each ecological niche presents a series of challenges to successful colonization with which streptococci have to contend. Some species exist in equilibrium with their host, neither stimulating nor submitting to immune defenses mounted against them. Most are either opportunistic or true pathogens responsible for diseases such as pharyngitis, tooth decay, necrotizing fasciitis, infective endocarditis, and meningitis. Part of the success of streptococci as colonizers is attributable to the spectrum of proteins expressed on their surfaces. Adhesins enable interactions with salivary, serum, and extracellular matrix components; host cells; and other microbes. This is the essential first step to colonization, the development of complex communities, and possible invasion of host tissues. The majority of streptococcal adhesins are anchored to the cell wall via a C-terminal LPxTz motif. Other proteins may be surface anchored through N-terminal lipid modifications, while the mechanism of cell wall associations for others remains unclear. Collectively, these surface-bound proteins provide Streptococcus species with a "coat of many colors," enabling multiple intimate contacts and interplays between the bacterial cell and the host. In vitro and in vivo studies have demonstrated direct roles for many streptococcal adhesins as colonization or virulence factors, making them attractive targets for therapeutic and preventive strategies against streptococcal infections. There is, therefore, much focus on applying increasingly advanced molecular techniques to determine the precise structures and functions of these proteins, and their regulatory pathways, so that more targeted approaches can be developed.
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Affiliation(s)
- Angela H Nobbs
- Oral Microbiology Unit, Department of Oral and Dental Science, University of Bristol, Bristol BS1 2LY, United Kingdom
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A novel fibronectin binding motif in MSCRAMMs targets F3 modules. PLoS One 2009; 4:e5412. [PMID: 19404402 PMCID: PMC2671840 DOI: 10.1371/journal.pone.0005412] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2008] [Accepted: 03/26/2009] [Indexed: 11/19/2022] Open
Abstract
Background BBK32 is a surface expressed lipoprotein and fibronectin (Fn)-binding microbial surface component recognizing adhesive matrix molecule (MSCRAMM) of Borrelia burgdorferi, the causative agent of Lyme disease. Previous studies from our group showed that BBK32 is a virulence factor in experimental Lyme disease and located the Fn-binding region to residues 21–205 of the lipoprotein. Methodology/Principal Findings Studies aimed at identifying interacting sites between BBK32 and Fn revealed an interaction between the MSCRAMM and the Fn F3 modules. Further analysis of this interaction showed that BBK32 can cause the aggregation of human plasma Fn in a similar concentration-dependent manner to that of anastellin, the superfibronectin (sFn) inducing agent. The resulting Fn aggregates are conformationally distinct from plasma Fn as indicated by a change in available thermolysin cleavage sites. Recombinant BBK32 and anastellin affect the structure of Fn matrices formed by cultured fibroblasts and inhibit endothelial cell proliferation similarly. Within BBK32, we have located the sFn-forming activity to a region between residues 160 and 175 which contains two sequence motifs that are also found in anastellin. Synthetic peptides mimicking these motifs induce Fn aggregation, whereas a peptide with a scrambled sequence motif was inactive, suggesting that these motifs represent the sFn-inducing sequence. Conclusions/Significance We conclude that BBK32 induces the formation of Fn aggregates that are indistinguishable from those formed by anastellin. The results of this study provide evidence for how bacteria can target host proteins to manipulate host cell activities.
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Vakonakis I, Staunton D, Ellis IR, Sarkies P, Flanagan A, Schor AM, Schor SL, Campbell ID. Motogenic sites in human fibronectin are masked by long range interactions. J Biol Chem 2009; 284:15668-75. [PMID: 19366708 PMCID: PMC2708863 DOI: 10.1074/jbc.m109.003673] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Fibronectin (FN) is a large extracellular matrix glycoprotein important for development and wound healing in vertebrates. Recent work has focused on the ability of FN fragments and embryonic or tumorigenic splicing variants to stimulate fibroblast migration into collagen gels. This activity has been localized to specific sites and is not exhibited by full-length FN. Here we show that an N-terminal FN fragment, spanning the migration stimulation sites and including the first three type III FN domains, also lacks this activity. A screen for interdomain interactions by solution-state NMR spectroscopy revealed specific contacts between the Fn N terminus and two of the type III domains. A single amino acid substitution, R222A, disrupts the strongest interaction, between domains (4-5)FnI and (3)FnIII, and restores motogenic activity to the FN N-terminal fragment. Anastellin, which promotes fibril formation, destabilizes (3)FnIII and disrupts the observed (4-5)FnI-(3)FnIII interaction. We discuss these findings in the context of the control of cellular activity through exposure of masked sites.
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Affiliation(s)
- Ioannis Vakonakis
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU , UK.
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Identification and structural analysis of type I collagen sites in complex with fibronectin fragments. Proc Natl Acad Sci U S A 2009; 106:4195-200. [PMID: 19251642 DOI: 10.1073/pnas.0812516106] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Collagen and fibronectin are major components of vertebrate extracellular matrices. Their association and distribution control the development and properties of diverse tissues, but thus far no structural information has been available for the complex formed. Here, we report binding of a peptide, derived from the alpha(1) chain of type I collagen, to the gelatin-binding domain of human fibronectin and present the crystal structure of this peptide in complex with the (8-9)FnI domain pair. Both gelatin-binding domain subfragments, (6)FnI(1-2)FnII(7)FnI and (8-9)FnI, bind the same specific sequence on D-period 4 of collagen I alpha(1), adjacent to the MMP-1 cleavage site. (8-9)FnI also binds the equivalent sequence of the alpha(2) chain. The collagen peptide adopts an antiparallel beta-strand conformation, similar to structures of proteins from pathogenic bacteria bound to FnI domains. Analysis of the type I collagen sequence suggests multiple putative fibronectin-binding sites compatible with our structural model. We demonstrate, by kinetic unfolding experiments, that the triple-helical collagen state is destabilized by (8-9)FnI. This finding suggests a role for fibronectin in collagen proteolysis and tissue remodeling.
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Esgleas M, Li Y, Hancock MA, Harel J, Dubreuil JD, Gottschalk M. Isolation and characterization of α-enolase, a novel fibronectin-binding protein from Streptococcus suis. Microbiology (Reading) 2008; 154:2668-2679. [DOI: 10.1099/mic.0.2008/017145-0] [Citation(s) in RCA: 128] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Miriam Esgleas
- Groupe de Recherche sur les Maladies Infectieuses du Porc (GREMIP) and Centre de Recherche en Infectiologie Porcine (CRIP), Faculté de Médecine Vétérinaire, Université de Montréal, Québec, Canada
| | - Yuanyi Li
- Groupe de Recherche sur les Maladies Infectieuses du Porc (GREMIP) and Centre de Recherche en Infectiologie Porcine (CRIP), Faculté de Médecine Vétérinaire, Université de Montréal, Québec, Canada
| | - Mark A. Hancock
- Sheldon Biotechnology Centre, McGill University, Montreal, Québec, Canada
| | - Josée Harel
- Groupe de Recherche sur les Maladies Infectieuses du Porc (GREMIP) and Centre de Recherche en Infectiologie Porcine (CRIP), Faculté de Médecine Vétérinaire, Université de Montréal, Québec, Canada
| | - J. Daniel Dubreuil
- Groupe de Recherche sur les Maladies Infectieuses du Porc (GREMIP) and Centre de Recherche en Infectiologie Porcine (CRIP), Faculté de Médecine Vétérinaire, Université de Montréal, Québec, Canada
| | - Marcelo Gottschalk
- Groupe de Recherche sur les Maladies Infectieuses du Porc (GREMIP) and Centre de Recherche en Infectiologie Porcine (CRIP), Faculté de Médecine Vétérinaire, Université de Montréal, Québec, Canada
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Meenan NAG, Visai L, Valtulina V, Schwarz-Linek U, Norris NC, Gurusiddappa S, Höök M, Speziale P, Potts JR. The tandem beta-zipper model defines high affinity fibronectin-binding repeats within Staphylococcus aureus FnBPA. J Biol Chem 2007; 282:25893-902. [PMID: 17606607 DOI: 10.1074/jbc.m703063200] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Binding of the fibronectin-binding protein FnBPA from Staphylococcus aureus to the human protein fibronectin has previously been implicated in the development of infective endocarditis, specifically in the processes of platelet activation and invasion of the endothelium. We recently proposed a model for binding of fibronectin to FnBPA in which the bacterial protein contains 11 potential binding sites (FnBPA-1 to FnBPA-11), each composed of motifs that bind to consecutive fibronectin type 1 modules in the N-terminal domain of fibronectin. Here we show that six of the 11 sites bind with dissociation constants in the nanomolar range; other sites bind more weakly. The high affinity binding sites include FnBPA-1, the sequence of which had previously been thought to be encompassed by the fibrinogen-binding A domain of FnBPA. Both the number and sequence conservation of the type-1 module binding motifs appears to be important for high affinity binding. The in vivo relevance of the in vitro binding studies is confirmed by the presence of antibodies in patients with S. aureus infections that specifically recognize complexes of these six high affinity repeats with fibronectin.
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Affiliation(s)
- Nicola A G Meenan
- Department of Biology, University of York, P.O. Box 373, York YO10 5YW, United Kingdom
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Tart AH, Walker MJ, Musser JM. New understanding of the group A Streptococcus pathogenesis cycle. Trends Microbiol 2007; 15:318-25. [PMID: 17524649 DOI: 10.1016/j.tim.2007.05.001] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2007] [Revised: 03/26/2007] [Accepted: 05/09/2007] [Indexed: 10/23/2022]
Abstract
Group A Streptococcus (GAS) has long been recognized as a human pathogen causing an exceptionally broad range of infections. Despite intense research, however, the molecular mechanisms of GAS disease remain unclear. Recently, many important discoveries have been made that shed light on GAS pathogenesis and open exciting avenues for future research. Advances in genome sequencing, microarray technology and proteomic analysis, in combination with the development of more suitable animal models, have markedly increased our knowledge of the mechanisms underlying GAS pathogenesis. The information gained from these studies will translate into improved diagnostics and new targets for therapeutic drugs and vaccines.
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Affiliation(s)
- Anne H Tart
- Center for Molecular and Translational Human Infectious Diseases Research, The Methodist Hospital Research Institute, and Department of Pathology, The Methodist Hospital, 6565 Fannin Street B490, Houston, TX 77030, USA
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Olive C, Schulze K, Sun HK, Ebensen T, Horváth A, Toth I, Guzman CA. Enhanced protection against Streptococcus pyogenes infection by intranasal vaccination with a dual antigen component M protein/SfbI lipid core peptide vaccine formulation. Vaccine 2006; 25:1789-97. [PMID: 17229503 DOI: 10.1016/j.vaccine.2006.11.031] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2006] [Revised: 10/26/2006] [Accepted: 11/13/2006] [Indexed: 11/23/2022]
Abstract
We investigated the efficacy of a synthetic Streptococcus pyogenes vaccine targeting two virulence factors using the Lipid Core Peptide (LCP) delivery system. BALB/c mice were immunised intranasally with LCPs containing peptides encompassing T-cell and B-cell epitopes of the conserved C-repeat region of the M protein (J8) or the fibronectin-binding repeats region (FNBR) of SfbI, or a combination formulation containing peptides representing both antigens. LCPs were co-administered with the TLR2/6 agonist MALP-2 as mucosal adjuvant. Humoral and cellular immune responses stimulated at systemic and mucosal levels were strongest in mice immunised with the dual antigen formulation. Mice were completely protected following a respiratory challenge with a lethal dose of a heterologous S. pyogenes strain, whereas there was 70% and 90% survival in mice immunised with LCP-J8 and LCP-FNBR, respectively. This is the first report demonstrating the elicitation of better protective immunity by a dual antigen component S. pyogenes vaccine.
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MESH Headings
- Adhesins, Bacterial/genetics
- Adhesins, Bacterial/immunology
- Adjuvants, Immunologic/administration & dosage
- Adjuvants, Immunologic/pharmacology
- Administration, Intranasal
- Animals
- Antibodies, Bacterial/blood
- Antigens, Bacterial/genetics
- Antigens, Bacterial/immunology
- Bacterial Outer Membrane Proteins/genetics
- Bacterial Outer Membrane Proteins/immunology
- Carrier Proteins/genetics
- Carrier Proteins/immunology
- Disease Models, Animal
- Epitopes, B-Lymphocyte/genetics
- Epitopes, B-Lymphocyte/immunology
- Epitopes, T-Lymphocyte/genetics
- Epitopes, T-Lymphocyte/immunology
- Leukocytes, Mononuclear/immunology
- Lipopeptides
- Mice
- Mice, Inbred BALB C
- Oligopeptides/administration & dosage
- Oligopeptides/pharmacology
- Streptococcal Infections/immunology
- Streptococcal Infections/prevention & control
- Streptococcal Vaccines/administration & dosage
- Streptococcal Vaccines/immunology
- Streptococcus pyogenes/genetics
- Streptococcus pyogenes/immunology
- Vaccines, Subunit/administration & dosage
- Vaccines, Subunit/immunology
- Vaccines, Synthetic/administration & dosage
- Vaccines, Synthetic/immunology
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Affiliation(s)
- C Olive
- Cooperative Research Centre for Vaccine Technology, Division of Infectious Diseases and Immunology, The Queensland Institute of Medical Research, PO Royal Brisbane Hospital, Brisbane, Queensland 4029, Australia.
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Samen UM, Eikmanns BJ, Reinscheid DJ. The transcriptional regulator RovS controls the attachment of Streptococcus agalactiae to human epithelial cells and the expression of virulence genes. Infect Immun 2006; 74:5625-35. [PMID: 16988238 PMCID: PMC1594887 DOI: 10.1128/iai.00667-06] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Streptococcus agalactiae is part of the normal flora of the human gastrointestinal tract and also the leading cause of bacterial infections in human newborns and immunocompromised adults. The colonization and infection of different regions within the human host require a regulatory network in S. agalactiae that senses environmental stimuli and controls the formation of specific virulence factors. In the present study, we characterized an Rgg-like transcriptional regulator, designated RovS (regulator of virulence in Streptococcus agalactiae). Deletion of the rovS gene in the genome of S. agalactiae resulted in strain 6313 DeltarovS, which exhibited an increased attachment to immobilized fibrinogen and a significant increase in adherence to the eukaryotic lung epithelial cell line A549. Quantification of expression levels of known and putative S. agalactiae virulence genes by real-time PCR revealed that RovS influences the expression of fbsA, gbs0230, sodA, rogB, and the cyl operon. The altered gene expression in mutant 6313 DeltarovS was restored by plasmid-mediated expression of rovS, confirming the RovS deficiency as the cause for the observed changes in virulence gene expression in S. agalactiae. DNA electrophoretic mobility shift assays showed that RovS specifically binds to the promoter regions of fbsA, gbs0230, sodA, and the cyl operon, indicating that RovS directly regulates their expression. Deletion and mutation studies in the promoter region of fbsA, encoding the main fibrinogen receptor in S. agalactiae, identified a RovS DNA motif. Similar motifs were also found in the promoter regions of gbs0230, sodA, and the cyl operon, and alignments allowed us to propose a consensus sequence for the DNA-binding site of RovS.
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Affiliation(s)
- Ulrike M Samen
- Department of Microbiology and Biotechnology, University of Ulm, Albert-Einstein-Allee 11, D-89069 Ulm, Germany.
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Schulze K, Olive C, Ebensen T, Guzmán CA. Intranasal vaccination with SfbI or M protein-derived peptides conjugated to diphtheria toxoid confers protective immunity against a lethal challenge with Streptococcus pyogenes. Vaccine 2006; 24:6088-95. [PMID: 16828529 DOI: 10.1016/j.vaccine.2006.05.024] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2006] [Revised: 05/16/2006] [Accepted: 05/16/2006] [Indexed: 10/24/2022]
Abstract
We investigated whether intranasal immunisation with diphtheria toxoid (DT) conjugated polypeptides encompassing T and B cell epitopes of the SfbI protein (FNBR) or a conformational-constrained B cell epitope of the M1 protein (J8) was able to confer protection against lethal mucosal challenge with a heterologous Streptococcus pyogenes strain. To this end, BALB/c mice were immunised with the conjugates. Strong antigen-specific antibody responses were observed in both serum and mucosal secretions. Vaccinated mice were challenged 10 days after the last boost by the intranasal route. Animals receiving FNBR-DT co-administered with either the cholera toxin B subunit (CTB) or the TLR 2/6 agonist MALP-2 were efficiently protected against the virulent S. pyogenes strain (90% and 70% survival, respectively), whereas those immunised with J8-DT plus either CTB or MALP-2 showed intermediate levels of protection (60% and 40%, respectively). The obtained results indicate that in our experimental animal model peptide-based conjugate vaccines represent a valid alternative to protect against streptococcal infection.
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Affiliation(s)
- Kai Schulze
- Department of Vaccinology, GBF-German Research Centre for Biotechnology, Mascheroder Weg 1, D-38124 Braunschweig, Germany.
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