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Wang C, Chantraine C, Viljoen A, Herr AB, Fey PD, Horswill AR, Mathelié-Guinlet M, Dufrêne YF. The staphylococcal biofilm protein Aap mediates cell-cell adhesion through mechanically distinct homophilic and lectin interactions. PNAS NEXUS 2022; 1:pgac278. [PMID: 36712378 PMCID: PMC9802226 DOI: 10.1093/pnasnexus/pgac278] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/10/2022] [Accepted: 12/01/2022] [Indexed: 12/04/2022]
Abstract
The accumulation phase of staphylococcal biofilms relies on both the production of an extracellular polysaccharide matrix and the expression of bacterial surface proteins. A prototypical example of such adhesive proteins is the long multidomain protein Aap (accumulation-associated protein) from Staphylococcus epidermidis, which mediates zinc-dependent homophilic interactions between Aap B-repeat regions through molecular forces that have not been investigated yet. Here, we unravel the remarkable mechanical strength of single Aap-Aap homophilic bonds between living bacteria and we demonstrate that intercellular adhesion also involves sugar binding through the lectin domain of the Aap A region. We find that the mechanical force needed to unfold individual β-sheet-rich G5-E domains from the Aap B-repeat regions is very high, ranging from 300 up to 1,000 pN at high loading rates, indicating these are extremely stable. This high mechanostability provides a means to the cells to form highly adhesive and cohesive biofilms capable of sustaining high physiological shear stress. Importantly, we identify a previously undescribed role of Aap in bacterial-bacterial adhesion, that is, heterophilic sugar binding by a specific lectin domain located in the N-terminal A region, which might be important to establish initial contacts between cells before strong homophilic bonds come into play. This study emphasizes the remarkable mechanical and binding properties of Aap as well as its wide diversity of adhesive functions.
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Affiliation(s)
| | | | - Albertus Viljoen
- Louvain Institute of Biomolecular Science and Technology, UCLouvain, Croix du Sud, 4-5, bte L7.07.07, B-1348 Louvain-la-Neuve, Belgium
| | - Andrew B Herr
- Divisions of Immunobiology and Infectious Diseases, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Paul D Fey
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Alexander R Horswill
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO 80045, USA
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2
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Han J, Poma A. Molecular Targets for Antibody-Based Anti-Biofilm Therapy in Infective Endocarditis. Polymers (Basel) 2022; 14:3198. [PMID: 35956712 PMCID: PMC9370930 DOI: 10.3390/polym14153198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 07/25/2022] [Accepted: 07/29/2022] [Indexed: 11/16/2022] Open
Abstract
Infective endocarditis (IE) is a heart disease caused by the infection of heart valves, majorly caused by Staphilococcus aureus. IE is initiated by bacteria entering the blood circulation in favouring conditions (e.g., during invasive procedures). So far, the conventional antimicrobial strategies based on the usage of antibiotics remain the major intervention for treating IE. Nevertheless, the therapeutic efficacy of antibiotics in IE is limited not only by the bacterial drug resistance, but also by the formation of biofilms, which resist the penetration of antibiotics into bacterial cells. To overcome these drawbacks, the development of anti-biofilm treatments that can expose bacteria and make them more susceptible to the action of antibiotics, therefore resulting in reduced antimicrobial resistance, is urgently required. A series of anti-biofilm strategies have been developed, and this review will focus in particular on the development of anti-biofilm antibodies. Based on the results previously reported in the literature, several potential anti-biofilm targets are discussed, such as bacterial adhesins, biofilm matrix and bacterial toxins, covering their antigenic properties (with the identification of potential promising epitopes), functional mechanisms, as well as the antibodies already developed against these targets and, where feasible, their clinical translation.
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Affiliation(s)
- Jiahe Han
- UCL Institute of Cardiovascular Science, The Rayne Building, 5 University Street, London WC1E 6JF, UK
| | - Alessandro Poma
- Division of Biomaterials and Tissue Engineering, UCL Eastman Dental Institute, Royal Free Hospital, UCL Medical School, Rowland Hill Street, London NW3 2PF, UK
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3
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Monoclonal Antibodies Targeting Surface-Exposed and Secreted Proteins from Staphylococci. Vaccines (Basel) 2021; 9:vaccines9050459. [PMID: 34064471 PMCID: PMC8147999 DOI: 10.3390/vaccines9050459] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 04/14/2021] [Accepted: 04/30/2021] [Indexed: 02/01/2023] Open
Abstract
Staphylococci (specifically Staphylococcus aureus and Staphylococcus epidermidis) are the causative agents of diseases ranging from superficial skin and soft tissue infections to severe conditions such as fatal pneumonia, bacteremia, sepsis and endocarditis. The widespread and indiscriminate use of antibiotics has led to serious problems of resistance to staphylococcal disease and has generated a renewed interest in alternative therapeutic agents such as vaccines and antibodies. Staphylococci express a large repertoire of surface and secreted virulence factors, which provide mechanisms (adhesion, invasion and biofilm development among others) for both bacterial survival in the host and evasion from innate and adaptive immunity. Consequently, the development of antibodies that target specific antigens would provide an effective protective strategy against staphylococcal infections. In this review, we report an update on efforts to develop anti-staphylococci monoclonal antibodies (and their derivatives: minibodies, antibody–antibiotic conjugates) and the mechanism by which such antibodies can help fight infections. We also provide an overview of mAbs used in clinical trials and highlight their therapeutic potential in various infectious contexts.
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4
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Raafat D, Otto M, Reppschläger K, Iqbal J, Holtfreter S. Fighting Staphylococcus aureus Biofilms with Monoclonal Antibodies. Trends Microbiol 2019; 27:303-322. [PMID: 30665698 DOI: 10.1016/j.tim.2018.12.009] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 12/10/2018] [Accepted: 12/18/2018] [Indexed: 02/07/2023]
Abstract
Staphylococcus aureus (S. aureus) is a notorious pathogen and one of the most frequent causes of biofilm-related infections. The treatment of S. aureus biofilms is hampered by the ability of the biofilm structure to shield bacteria from antibiotics as well as the host's immune system. Therefore, new preventive and/or therapeutic interventions, including the use of antibody-based approaches, are urgently required. In this review, we describe the mechanisms by which anti-S. aureus antibodies can help in combating biofilms, including an up-to-date overview of monoclonal antibodies currently in clinical trials. Moreover, we highlight ongoing efforts in passive vaccination against S. aureus biofilm infections, with special emphasis on promising targets, and finally indicate the direction into which future research could be heading.
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Affiliation(s)
- Dina Raafat
- Department of Microbiology and Immunology, Faculty of Pharmacy, Alexandria University, Egypt; Current affiliation: Department of Immunology, University Medicine Greifswald, Greifswald, Germany
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, US National Institutes of Health, Bethesda, MD, USA
| | - Kevin Reppschläger
- Department of Immunology, University Medicine Greifswald, Greifswald, Germany
| | - Jawad Iqbal
- Department of Immunology, University Medicine Greifswald, Greifswald, Germany
| | - Silva Holtfreter
- Department of Immunology, University Medicine Greifswald, Greifswald, Germany.
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5
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Speziale P, Rindi S, Pietrocola G. Antibody-Based Agents in the Management of Antibiotic-Resistant Staphylococcus aureus Diseases. Microorganisms 2018. [PMID: 29533985 PMCID: PMC5874639 DOI: 10.3390/microorganisms6010025] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Staphylococcus aureus is a human pathogen that can cause a wide spectrum of diseases, including sepsis, pneumonia, arthritis, and endocarditis. Ineffective treatment of a number of staphylococcal infections with antibiotics is due to the development and spread of antibiotic-resistant strains following decades of antibiotic usage. This has generated renewed interest within the scientific community in alternative therapeutic agents, such as anti-S. aureus antibodies. Although the role of antibodies in the management of S. aureus diseases is controversial, the success of this pathogen in neutralizing humoral immunity clearly indicates that antibodies offer the host extensive protection. In this review, we report an update on efforts to develop antibody-based agents, particularly monoclonal antibodies, and their therapeutic potential in the passive immunization approach to the treatment and prevention of S. aureus infections.
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Affiliation(s)
- Pietro Speziale
- Department of Molecular Medicine, University of Pavia, 27100 Pavia, Italy.
- Department of Industrial and Information Engineering, University of Pavia, 27100 Pavia, Italy.
| | - Simonetta Rindi
- Department of Molecular Medicine, University of Pavia, 27100 Pavia, Italy.
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6
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Arciola CR, Balaban N, Baldassarri L, Fromm K, HÄnsch GM, Obst U, Presterl E, Stefani S, Verran J, Visai L, Arciola CR, Balaban N, Baldassarri L, Fromm K, Hänsch GM, Obst U, Presterl E, Stefani S, Verran J, Visai L. Combating Implant Infections. Remarks by a Women's Team. Int J Artif Organs 2018; 31:858-64. [DOI: 10.1177/039139880803100915] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Research on implant infections requires cooperative efforts and integration between basic and clinical expertises. An international group of women scientists is acting together in this field. The main research topics of the participants of this group are described. Formation of bacterial biofilms, antibiotic resistance and production of virulence factors like adhesins and toxins are investigated. New biomaterials, coatings and drugs designed to inhibit microbial adhesion are evaluated, and infection-resistant biomaterials are under study, such as a novel heparinizable polycarbonate-urethane (Bionate) or incorporation of diamino-diamide-diol (PIME) to reduce bacterial attachment. The correlation between biofilm production and the accessory-gene-regulator (agr) is investigated in Staphylococcus aureus. The ability to form biofilm has also been shown to be one of the important virulence factors of Enterococcus faecalis, favouring colonization of inert and biological surfaces. The study of quorum sensing has led to the discovery of a quorum sensing inhibitor termed RIP that suppresses staphylococcal biofilm and infections. The immune response and the local defence mechanisms of the host against implant-associated infections, activation and infiltration of immunocompetent cells into the sites of infection have been studied in patients with implant-associated osteomyelitis. Production of monoclonal antibodies (mAbs) as possible vaccines against the staphylococcal collagen-binding MSCRAMMs is in progress. (Int J Artif Organs 2008; 31: 858–64)
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Affiliation(s)
- C. R. Arciola
- Research Unit on Implant Infections, Rizzoli Orthopedic Institute and Experimental Pathology Department, University of Bologna, Bologna - Italy
| | - N. Balaban
- Department of Biomedical Sciences, Tufts University Cummings School of Veterinary Medicine, North Grafton, Massachusetts - USA
| | - L. Baldassarri
- Department of Infectious, Parasitic and Immunomediated Diseases, National Institute of Health, Rome - Italy
| | - K. Fromm
- Chemistry Department, University of Fribourg, Fribourg - Switzerland
| | - G. M. HÄnsch
- Institute for Immunology of the University of Heidelberg, Heidelberg - Germany
| | - U. Obst
- Department of Environmental Microbiology, Institute for Technical Chemistry-Water Technology and Geotechnology, Eggenstein-Leopoldshafen - Germany
| | - E. Presterl
- Department of Medicine I, Division of Infectious Diseases and Tropical Medicine, University of Vienna, Vienna - Austria
| | - S. Stefani
- Department of Microbiological and Gynecological Sciences, University of Catania, Catania - Italy
| | - J. Verran
- Manchester Metropolitan University, Manchester - United Kingdom
| | - L. Visai
- University of Pavia, Department of Biochemistry, Pavia - Italy
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7
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Madani A, Garakani K, Mofrad MRK. Molecular mechanics of Staphylococcus aureus adhesin, CNA, and the inhibition of bacterial adhesion by stretching collagen. PLoS One 2017; 12:e0179601. [PMID: 28665944 PMCID: PMC5493303 DOI: 10.1371/journal.pone.0179601] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 05/31/2017] [Indexed: 02/05/2023] Open
Abstract
Bacterial adhesion to collagen, the most abundant protein in humans, is a critical step in the initiation and persistence of numerous bacterial infections. In this study, we explore the collagen binding mechanism of the multi-modular cell wall anchored collagen adhesin (CNA) in Staphylococcus aureus and examine how applied mechanical forces can modulate adhesion ability. The common structural-functional elements and domain organization of CNA are present across over 50 genera of bacteria. Through the use of molecular dynamics models and normal mode analysis, we shed light on the CNA's structural and conformational dynamics and its interactions with collagen that lead to collagen binding. Our results suggest that the linker region, CNA165-173, acts as a hinge exhibiting bending, extensional, and torsional modes of structural flexibility and its residues are key in the interaction of the CNA-collagen complex. Steered molecular dynamics simulations were conducted with umbrella sampling. During the course of these simulations, the 'locking' latch from the CNA N2 domain was dissociated from its groove in the CNA N1 domain, implying the importance of the latch for effective ligand binding. Finally, we observed that the binding efficiency of the CNA N1-N2 domains to collagen decreases greatly with increasing tensile force application to the collagen peptides. Thus, CNA and similar adhesins might preferentially bind to sites in which collagen fibers are cleaved, such as in wounded, injured, or inflamed tissues, or in which the collagenous tissue is less mature. As alternative techniques for control of bacterial infection are in-demand due to the rise of bacterial antibiotic resistance, results from our computational studies with respect to the mechanoregulation of the collagen binding site may inspire new therapeutics and engineering solutions by mechanically preventing colonization and/or further pathogenesis.
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Affiliation(s)
- Ali Madani
- Molecular Cell Biomechanics Laboratory, Departments of Bioengineering and Mechanical Engineering, University of California, Berkeley, California, United States of America
| | - Kiavash Garakani
- Molecular Cell Biomechanics Laboratory, Departments of Bioengineering and Mechanical Engineering, University of California, Berkeley, California, United States of America
| | - Mohammad R. K. Mofrad
- Molecular Cell Biomechanics Laboratory, Departments of Bioengineering and Mechanical Engineering, University of California, Berkeley, California, United States of America
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Lab, Berkeley, California, United States of America
- * E-mail:
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8
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Valotteau C, Prystopiuk V, Pietrocola G, Rindi S, Peterle D, De Filippis V, Foster TJ, Speziale P, Dufrêne YF. Single-Cell and Single-Molecule Analysis Unravels the Multifunctionality of the Staphylococcus aureus Collagen-Binding Protein Cna. ACS NANO 2017; 11:2160-2170. [PMID: 28151647 DOI: 10.1021/acsnano.6b08404] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The collagen-binding protein Cna is a prototype cell surface protein from Staphylococcus aureus which fulfils important physiological functions during pathogenesis. While it is established that Cna binds to collagen (Cn) via the high-affinity collagen hug mechanism, whether this protein is engaged in other ligand-binding mechanisms is poorly understood. Here, we use atomic force microscopy to demonstrate that Cna mediates attachment to two structurally and functionally different host proteins, i.e., the complement system protein C1q and the extracellular matrix protein laminin (Lam), through binding mechanisms that differ from the collagen hug. We show that single Cna-C1q and Cna-Lam bonds are much weaker than the high-affinity Cna-Cn bond and that their formation does not require the B-region of Cna. At the whole cell level, we find that bacterial adhesion to C1q-substrates involves only one (or two) molecular bond(s), while adhesion to Lam is mediated by multiple bonds, thus suggesting that multivalent or cooperative interactions may enhance the strength of adhesion. Both C1q and Lam interactions can be efficiently blocked by monoclonal antibodies directed against the minimal Cn-binding domain of Cna. These results show that Cna is a multifunctional protein capable of binding to multiple host ligands through mechanisms that differ from the classical collagen hug.
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Affiliation(s)
- Claire Valotteau
- Institute of Life Sciences, Université Catholique de Louvain , Croix du Sud, 4-5, bte L7.07.06, Louvain-la-Neuve B-1348, Belgium
| | - Valeria Prystopiuk
- Institute of Life Sciences, Université Catholique de Louvain , Croix du Sud, 4-5, bte L7.07.06, Louvain-la-Neuve B-1348, Belgium
| | - Giampiero Pietrocola
- Department of Molecular Medicine, Unit of Biochemistry, University of Pavia , Viale Taramelli 3/b, Pavia 27100, Italy
| | - Simonetta Rindi
- Department of Molecular Medicine, Unit of Biochemistry, University of Pavia , Viale Taramelli 3/b, Pavia 27100, Italy
| | - Daniele Peterle
- Laboratory of Protein Chemistry, Department of Pharmaceutical and Pharmacological Sciences, University of Padua , via F. Marzolo 5, Padova 35131, Italy
| | - Vincenzo De Filippis
- Laboratory of Protein Chemistry, Department of Pharmaceutical and Pharmacological Sciences, University of Padua , via F. Marzolo 5, Padova 35131, Italy
| | - Timothy J Foster
- Department of Microbiology, Trinity College Dublin , Dublin 2, Ireland
| | - Pietro Speziale
- Department of Molecular Medicine, Unit of Biochemistry, University of Pavia , Viale Taramelli 3/b, Pavia 27100, Italy
| | - Yves F Dufrêne
- Institute of Life Sciences, Université Catholique de Louvain , Croix du Sud, 4-5, bte L7.07.06, Louvain-la-Neuve B-1348, Belgium
- Walloon Excellence in Life sciences and Biotechnology (WELBIO) , Liège 4000, Belgium
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9
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Genta I, Colonna C, Conti B, Caliceti P, Salmaso S, Speziale P, Pietrocola G, Chiesa E, Modena T, Dorati R. CNA-loaded PLGA nanoparticles improve humoral response againstS. aureus-mediated infections in a mouse model: subcutaneous vs. nasal administration strategy. J Microencapsul 2016; 33:750-762. [DOI: 10.1080/02652048.2016.1260661] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Ida Genta
- Department of Drug Sciences, University of Pavia, Pavia, Italy
| | - Claudia Colonna
- Department of Drug Sciences, University of Pavia, Pavia, Italy
| | - Bice Conti
- Department of Drug Sciences, University of Pavia, Pavia, Italy
| | - Paolo Caliceti
- Department of Pharmaceutical Sciences, University of Padua, Padova, Italy
| | - Stefano Salmaso
- Department of Pharmaceutical Sciences, University of Padua, Padova, Italy
| | - Pietro Speziale
- Department of Molecular Medicine, Unit of Biochemistry, University of Pavia, Pavia, Italy
| | - Giampiero Pietrocola
- Department of Molecular Medicine, Unit of Biochemistry, University of Pavia, Pavia, Italy
| | - Enrica Chiesa
- Department of Drug Sciences, University of Pavia, Pavia, Italy
| | - Tiziana Modena
- Department of Drug Sciences, University of Pavia, Pavia, Italy
| | - Rossella Dorati
- Department of Drug Sciences, University of Pavia, Pavia, Italy
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10
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Herman-Bausier P, Valotteau C, Pietrocola G, Rindi S, Alsteens D, Foster TJ, Speziale P, Dufrêne YF. Mechanical Strength and Inhibition of the Staphylococcus aureus Collagen-Binding Protein Cna. mBio 2016; 7:e01529-16. [PMID: 27795393 PMCID: PMC5080380 DOI: 10.1128/mbio.01529-16] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 10/06/2016] [Indexed: 11/20/2022] Open
Abstract
The bacterial pathogen Staphylococcus aureus expresses a variety of cell surface adhesion proteins that bind to host extracellular matrix proteins. Among these, the collagen (Cn)-binding protein Cna plays important roles in bacterium-host adherence and in immune evasion. While it is well established that the A region of Cna mediates ligand binding, whether the repetitive B region has a dedicated function is not known. Here, we report the direct measurement of the mechanical strength of Cna-Cn bonds on living bacteria, and we quantify the antiadhesion activity of monoclonal antibodies (MAbs) targeting this interaction. We demonstrate that the strength of Cna-Cn bonds in vivo is very strong (~1.2 nN), consistent with the high-affinity "collagen hug" mechanism. The B region is required for strong ligand binding and has been found to function as a spring capable of sustaining high forces. This previously undescribed mechanical response of the B region is of biological significance as it provides a means to project the A region away from the bacterial surface and to maintain bacterial adhesion under conditions of high forces. We further quantified the antiadhesion activity of MAbs raised against the A region of Cna directly on living bacteria without the need for labeling or purification. Some MAbs are more efficient in blocking single-cell adhesion, suggesting that they act as competitive inhibitors that bind Cna residues directly involved in ligand binding. This report highlights the role of protein mechanics in activating the function of staphylococcal adhesion proteins and emphasizes the potential of antibodies to prevent staphylococcal adhesion and biofilm formation. IMPORTANCE Cna is a collagen (Cn)-binding protein from Staphylococcus aureus that is involved in pathogenesis. Currently, we know little about the functional role of the repetitive B region of the protein. Here, we unravel the mechanical strength of Cna in living bacteria. We show that single Cna-Cn bonds are very strong, reflecting high-affinity binding by the collagen hug mechanism. We discovered that the B region behaves as a nanospring capable of sustaining high forces. This unanticipated mechanical response, not previously described for any staphylococcal adhesin, favors a model in which the B region has a mechanical function that is essential for strong ligand binding. Finally, we assess the antiadhesion activity of monoclonal antibodies against Cna, suggesting that they could be used to inhibit S. aureus adhesion.
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Affiliation(s)
| | - Claire Valotteau
- Institute of Life Sciences, Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Giampiero Pietrocola
- Department of Molecular Medicine, Unit of Biochemistry, University of Pavia, Pavia, Italy
| | - Simonetta Rindi
- Department of Molecular Medicine, Unit of Biochemistry, University of Pavia, Pavia, Italy
| | - David Alsteens
- Institute of Life Sciences, Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Timothy J Foster
- Department of Microbiology, Trinity College Dublin, Dublin, Ireland
| | - Pietro Speziale
- Department of Molecular Medicine, Unit of Biochemistry, University of Pavia, Pavia, Italy
| | - Yves F Dufrêne
- Institute of Life Sciences, Université catholique de Louvain, Louvain-la-Neuve, Belgium
- Walloon Excellence in Life Sciences and Biotechnology (WELBIO), Wallonia, Belgium
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11
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Hao Z, Fan W, Hao J, Wu X, Zeng GQ, Zhang LJ, Nie SF, Wang XD. Efficient delivery of micro RNA to bone-metastatic prostate tumors by using aptamer-conjugated atelocollagen in vitro and in vivo. Drug Deliv 2014; 23:874-81. [PMID: 24892627 DOI: 10.3109/10717544.2014.920059] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Bone is the primary site of skeletal metastasis in prostate cancer (PCa). Atelocollagen (ATE)-mediated siRNA delivery system can be used to silence endogenous genes involved in PCa metastatic tumor cell growth. However, we hope that the delivery system can target PCa cells to reduce damage to the bone tissue and improve the therapeutic effect. RNA aptamer (APT) A10-3.2 has been used as a ligand to target PCa cells that express prostate-specific membrane antigen (PSMA). APT was investigated as a PSMA-targeting ligand in the design of an ATE-based microRNA (miRNA; miR-15a and miR-16-1) vector to PCa bone metastasis. To observe the targeted delivery and transfection efficiency of ATE-APT in PSMA-overexpressing cells, luciferase activity and biodistribution of nanoparticles in Balb/c mice was analyzed. The anticancer effect of nanoparticles in vivo was investigated using the survival times of human PCa bone metastasis mice model. Luciferase assays of pGL-3 expression against PC3 (PSMA(-)) and LNCaP (PSMA(+)) cells showed that the transfection efficiency of the synthesized DNA/ATE-APT complex was higher than that of the DNA/ATE complex. The anticancer efficacy of miRNA/ATE-APT was superior to those of other treatments in vivo. This PSMA-targeted system may prove useful in widening the therapeutic window and allow for selective killing of PCa cells in bone metastatic foci.
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Affiliation(s)
- Zhao Hao
- a Department of Orthopedics , The 425th Hospital of PLA , Sanya , China
| | - Wei Fan
- b Department of Pharmacy , The 425th Hospital of PLA , Sanya , China
| | - Jian Hao
- c Department of Orthopedics , Nankai Hospital , Tianjin , China , and
| | - Xin Wu
- d Department of Pharmacy , Changhai Hospital, Second Military Medical University , Shanghai , China
| | - Guo Qing Zeng
- b Department of Pharmacy , The 425th Hospital of PLA , Sanya , China
| | - Li Juan Zhang
- d Department of Pharmacy , Changhai Hospital, Second Military Medical University , Shanghai , China
| | - Sui Feng Nie
- a Department of Orthopedics , The 425th Hospital of PLA , Sanya , China
| | - Xu Dong Wang
- b Department of Pharmacy , The 425th Hospital of PLA , Sanya , China
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12
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Berisio R, Vitagliano L. Polyproline and triple helix motifs in host-pathogen recognition. Curr Protein Pept Sci 2013; 13:855-65. [PMID: 23305370 PMCID: PMC3707005 DOI: 10.2174/138920312804871157] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Revised: 08/10/2012] [Accepted: 08/30/2012] [Indexed: 01/18/2023]
Abstract
Secondary structure elements often mediate protein-protein interactions. Despite their low abundance in folded proteins, polyproline II (PPII) and its variant, the triple helix, are frequently involved in protein-protein interactions, likely due to their peculiar propensity to be solvent-exposed. We here review the role of PPII and triple helix in mediating host-pathogen interactions, with a particular emphasis to the structural aspects of these processes. After a brief description of the basic structural features of these elements, examples of host-pathogen interactions involving these motifs are illustrated. Literature data suggest that the role played by PPII motif in these processes is twofold. Indeed, PPII regions may directly mediate interactions between proteins of the host and the pathogen. Alternatively, PPII may act as structural spacers needed for the correct positioning of the elements needed for adhesion and infectivity. Recent investigations have highlighted that collagen triple helix is also a common target for bacterial adhesins. Although structural data on complexes between adhesins and collagen models are rather limited, experimental and theoretical studies have unveiled some interesting clues of the recognition process. Interestingly, very recent data show that not only is the triple helix used by pathogens as a target in the host-pathogen interaction but it may also act as a bait in these processes since bacterial proteins containing triple helix regions have been shown to interact with host proteins. As both PPII and triple helix expose several main chain non-satisfied hydrogen bond acceptors and donors, both elements are highly solvated. The preservation of the solvation state of both PPII and triple helix upon protein-protein interaction is an emerging aspect that will be here thoroughly discussed.
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Affiliation(s)
- Rita Berisio
- Istituto di Biostrutture e Bioimmagini, CNR via Mezzocannone 16, I-80134 Napoli, Italy
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13
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Library screen identifies Enterococcus faecalis CcpA, the catabolite control protein A, as an effector of Ace, a collagen adhesion protein linked to virulence. J Bacteriol 2013; 195:4761-8. [PMID: 23974022 DOI: 10.1128/jb.00706-13] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Enterococcus faecalis cell wall-anchored protein Ace is an important virulence factor involved in cell adhesion and infection. Expression of Ace on the cell surface is affected by many factors, including stage of growth, culture temperature, and environmental components, such as serum, urine, and collagen. However, the mechanisms that regulate or modulate Ace display are not well understood. With interest in identifying genes associated with Ace expression, we utilized a whole-cell enzyme-linked immunosorbent assay (ELISA)-based screening method to identify mutants from a transposon insertion mutant library which exhibited distinct Ace surface expression profiles. We identified a ccpA insertion mutant which showed significantly decreased levels of Ace surface expression at early growth phase versus those of wild-type OG1RF. Confirmation of the observation was achieved through flow cytometry and complementation analysis. Compared to the wild type, the E. faecalis ccpA mutant had an impaired ability to adhere to collagen when grown to early exponential phase, consistent with the lack of Ace expression in the early growth phase. As a key component of carbon catabolite regulation, CcpA has been previously reported to play a critical role in regulating expression of proteins involved in E. faecalis carbohydrate uptake and utilization. Our discovery is the first to associate CcpA with the production of a major E. faecalis virulence factor, providing new insights into the regulation of E. faecalis pathogenesis.
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Abstract
The SasG surface protein of Staphylococcus aureus has been shown to promote the formation of biofilm. SasG comprises an N-terminal A domain and repeated B domains. Here we demonstrate that SasG is involved in the accumulation phase of biofilm, a process that requires a physiological concentration of Zn(2+). The B domains, but not the A domain, are required. Purified recombinant B domain protein can form dimers in vitro in a Zn(2+)-dependent fashion. Furthermore, the protein can bind to cells that have B domains anchored to their surface and block biofilm formation. The full-length SasG protein exposed on the cell surface is processed within the B domains to a limited degree, resulting in cleaved proteins of various lengths being released into the supernatant. Some of the released molecules associate with the surface-exposed B domains that remain attached to the cell. Studies using inhibitors and mutants failed to identify any protease that could cause the observed cleavage within the B domains. Extensively purified recombinant B domain protein is very labile, and we propose that cleavage occurs spontaneously at labile peptide bonds and that this is necessary for biofilm formation.
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Speziale P, Pietrocola G, Rindi S, Provenzano M, Provenza G, Di Poto A, Visai L, Arciola CR. Structural and functional role of Staphylococcus aureus surface components recognizing adhesive matrix molecules of the host. Future Microbiol 2009; 4:1337-52. [DOI: 10.2217/fmb.09.102] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Staphylococcus aureus is a versatile and harmful human pathogen in both hospital- and community-acquired infections. S. aureus can initiate host infection by adhering to components of the extracellular matrix. Adherence is mediated by a variety of protein adhesins of the microbial surface component recognizing adhesive matrix molecule (MSCRAMM) family. In this article, we describe these MSCRAMMs in terms of structural organization and ligand-binding capacity and discuss their role as a possible target for immunotherapy.
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Affiliation(s)
- Pietro Speziale
- Department of Biochemistry, Viale Taramelli 3/b 27100 Pavia, Italy
| | | | - Simonetta Rindi
- Department of Biochemistry, Viale Taramelli 3/b 27100 Pavia, Italy
| | - Maria Provenzano
- Department of Biochemistry, Viale Taramelli 3/b 27100 Pavia, Italy
| | - Giulio Provenza
- Department of Biochemistry, Viale Taramelli 3/b 27100 Pavia, Italy
| | | | - Livia Visai
- Department of Biochemistry, Viale Taramelli 3/b 27100 Pavia, Italy and Center for Tissue Engineering (CIT), Via Ferrata 1, 27100 Pavia, Italy
| | - Carla Renata Arciola
- Research Unit on Implant Infections, Rizzoli Orthopaedic Institute, Via di Barbiano 1/10, 40136 Bologna, Italy and Experimental Pathology Department, University of Bologna, Via S. Giacomo 14, 40126 Bologna, Italy
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16
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Brady RA, Calhoun JH, Leid JG, Shirtliff ME. Infections of Orthopaedic Implants and Devices. SPRINGER SERIES ON BIOFILMS 2008. [DOI: 10.1007/978-3-540-68119-9_2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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17
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Fibronectin binding and proteolytic degradation by Leishmania and effects on macrophage activation. Infect Immun 2008; 76:1738-47. [PMID: 18212076 DOI: 10.1128/iai.01274-07] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Infection by vector-borne protozoa of the genus Leishmania occurs by the deposition of parasites within the skin of the mammalian host, where they eventually bind to and are phagocytized by Mphis. Our previous work supported the idea that parasites can interact with extracellular matrix and basement membrane proteins, such as fibronectin (FN), within the skin, leading to enhanced invasion. In this report, we extend these findings and show that both promastigotes and amastigotes of Leishmania species can bind directly to soluble FN and laminin (LM) and that promastigotes express a distinct surface protein of approximately 60 kDa that binds both FN and LM. Promastigotes of multiple Leishmania species can rapidly degrade FN by using surface-localized and secreted metalloprotease (leishmanolysin). FN degradation at the surfaces of amastigotes is leishmanolysin dependent, whereas both secreted leishmanolysin and cysteine protease B contribute to extracellular FN degradation. Leishmania-degraded FN decreased the production of reactive oxygen intermediates by parasite-infected macrophages and affected the accumulation of intracellular parasites. These findings show that both parasite stages of Leishmania species bind to and proteolytically degrade FN at the parasite surface and distantly through secreted proteases and that degraded forms of FN can influence the activation state of parasite-infected macrophages.
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Pietrocola G, Valtulina V, Rindi S, Jost BH, Speziale P. Functional and structural properties of CbpA, a collagen-binding protein from Arcanobacterium pyogenes. MICROBIOLOGY-SGM 2007; 153:3380-3389. [PMID: 17906137 DOI: 10.1099/mic.0.2007/009100-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Arcanobacterium pyogenes, an opportunistic pathogen of economically important food animals, is the causative agent of liver abscesses in feedlot cattle, osteomyelitis in turkeys, and pneumonia and arthritis in pigs. Previous studies identified the first A. pyogenes adhesin, CbpA, a protein located on the bacterial surface which has the ability to bind collagen and promotes adhesion to the host cells. The protein has an N-terminal ligand-binding region (region A) and a C-terminal repetitive domain (region B). In this study we found that CbpA bound to almost all the collagen types tested but not to other proteins, and it displayed a propensity to interact with several collagenous peptides derived by CNBr cleavage of type I and II collagens. The K(D) values of CbpA for type I and II collagens and collagen peptides determined by solid-phase binding assay and intrinsic tryptophan fluorescence were in the range of 1-15 nM. It was also found that CbpA and its A region bound fibronectin, and that collagen and fibronectin interacted with distinct subsites. Anti-CbpA antibodies were effective at inhibiting both binding of isolated CbpA and bacterial adhesion to immobilized collagen, suggesting that CbpA is a functional collagen-binding adhesin. Analysis of the immunological cross-reactivity of CbpA with antibodies against other bacterial collagen-binding proteins indicated that CbpA is immunologically related to ACE from Enterococcus faecalis but not to CNA from Staphylococcus aureus or Acm from Enterococcus faecium. Far-UV and near-UV circular dichroism spectra showed that full-length CbpA and its region A are mainly composed of beta-sheet with only a minor alpha-helical component and that both the proteins have a well-defined tertiary structure.
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Affiliation(s)
- Giampiero Pietrocola
- University of Pavia, Department of Biochemistry, Viale Taramelli 3/B, 27100 Pavia, Italy
| | - Viviana Valtulina
- University of Pavia, Department of Biochemistry, Viale Taramelli 3/B, 27100 Pavia, Italy
| | - Simonetta Rindi
- University of Pavia, Department of Biochemistry, Viale Taramelli 3/B, 27100 Pavia, Italy
| | - B Helen Jost
- Department of Veterinary Science and Microbiology, The University of Arizona, Tucson, AZ 85721, USA
| | - Pietro Speziale
- University of Pavia, Department of Biochemistry, Viale Taramelli 3/B, 27100 Pavia, Italy
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Ponnuraj K, Narayana SVL. Crystal structure of ACE19, the collagen binding subdomain of Enterococus faecalis surface protein ACE. Proteins 2007; 69:199-203. [PMID: 17557326 DOI: 10.1002/prot.21464] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Karthe Ponnuraj
- School of Optometry and Center for Biophysical Sciences and Engineering, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
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20
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Nallapareddy SR, Sillanpää J, Ganesh VK, Höök M, Murray BE. Inhibition of Enterococcus faecium adherence to collagen by antibodies against high-affinity binding subdomains of Acm. Infect Immun 2007; 75:3192-6. [PMID: 17438036 PMCID: PMC1932878 DOI: 10.1128/iai.02016-06] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Strains of Enterococcus faecium express a cell wall-anchored protein, Acm, which mediates adherence to collagen. Here, we (i) identify the minimal and high-affinity binding subsegments of Acm and (ii) show that anti-Acm immunoglobulin Gs (IgGs) purified against these subsegments reduced E. faecium TX2535 strain collagen adherence up to 73 and 50%, respectively, significantly more than the total IgGs against the full-length Acm A domain (28%) (P < 0.0001). Blocking Acm adherence with functional subsegment-specific antibodies raises the possibility of their use as therapeutic or prophylactic agents.
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Affiliation(s)
- Sreedhar R Nallapareddy
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical School at Houston, 6431 Fannin Street, MSB 2.112, Houston, TX 77030, USA
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21
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Liu Q, Ponnuraj K, Xu Y, Ganesh VK, Sillanpää J, Murray BE, Narayana SVL, Höök M. The Enterococcus faecalis MSCRAMM ACE binds its ligand by the Collagen Hug model. J Biol Chem 2007; 282:19629-37. [PMID: 17392280 DOI: 10.1074/jbc.m611137200] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We have determined the crystal structure of the ligand binding segment of the Enterococcus faecalis collagen binding MSCRAMM ACE (microbial surface components recognizing adhesive matrix molecules adhesin of collagen from enterococci). This segment is composed of two subdomains, N(1) and N(2), each adopting an IgG-like fold and forming a putative collagen binding surface at the interface between the two subdomains. This structure is very similar to that recently reported for CNA, the collagen binding MSCRAMM of Staphylococcus aureus, for which a unique ligand binding mechanism called the Collagen Hug was proposed. We suggest that ACE binds collagen by a similar mechanism and present the first biochemical evidence for this binding model. Replacing residues in the putative collagen binding trench of ACE N(2) with Ala residues affected collagen binding. A closed conformation of ACE stabilized by an engineered disulfide bond is unable to bind collagen. Finally, the importance of the residues in the N(2) extension in stabilizing the MSCRAMM-ligand complex is demonstrated by selected point and truncation mutations.
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Affiliation(s)
- Qing Liu
- Center for Extracellular Matrix Biology, Texas A&M University System Health Science Center, Albert B. Alkek Institute of Biosciences and Technology, Houston, Texas 77030, USA
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22
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Ymele-Leki P, Ross JM. Erosion from Staphylococcus aureus biofilms grown under physiologically relevant fluid shear forces yields bacterial cells with reduced avidity to collagen. Appl Environ Microbiol 2007; 73:1834-41. [PMID: 17277217 PMCID: PMC1828840 DOI: 10.1128/aem.01319-06] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
An estimated 65% of infective diseases are associated with the presence of bacterial biofilms. Biofilm-issued planktonic cells promote blood-borne, secondary sites of infection by the inoculation of the infected sites with bacteria from the intravascular space. To investigate the potential role of early detachment events in initiating secondary infections, we studied the phenotypic attributes of Staphylococcus aureus planktonic cells eroding from biofilms with respect to expression of the collagen adhesin, CNA. The collagen-binding abilities of S. aureus have been correlated to the development of osteomyelitis and septic arthritis. In this study, we focused on the impact of CNA expression on S. aureus adhesion to immobilized collagen in vitro under physiologically relevant shear forces. In contrast to the growth phase-dependent adhesion properties characteristic of S. aureus cells grown in suspension, eroding planktonic cells expressed invariant and lower effective adhesion rates regardless of the age of the biofilm from which they originated. These results correlated directly with the surface expression level of CNA. However, subsequent analysis revealed no qualitative differences between biofilms initiated with suspension cells and secondary biofilms initiated with biofilm-shed planktonic cells. Taken together, our findings suggest that, despite their low levels of CNA expression, S. aureus planktonic cells shed from biofilms retain the capacity for metastatic spread and the initiation of secondary infection. These findings demonstrate the need for a better understanding of the phenotypic properties of eroding planktonic cells, which could lead to new therapeutic strategies to target secondary infections.
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Affiliation(s)
- Patrick Ymele-Leki
- Department of Chemical and Biochemical Engineering, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA
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23
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Pourmand MR, Clarke SR, Schuman RF, Mond JJ, Foster SJ. Identification of antigenic components of Staphylococcus epidermidis expressed during human infection. Infect Immun 2006; 74:4644-54. [PMID: 16861652 PMCID: PMC1539593 DOI: 10.1128/iai.00521-06] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A spectrum of in vivo-expressed Staphylococcus epidermidis antigens was identified by probing a bacteriophage lambda library of S. epidermidis genomic DNA with human serum from infected and uninfected individuals. This analysis resulted in identification of 53 antigen-encoding loci. Six antigenic polypeptides were expressed from these loci and purified. These polypeptides were the propeptide, mature amidase, and repeat sequence domains of the major autolysin AtlE, GehD (lipase), and two members of a conserved family of surface proteins (ScaA [AaE] and ScaB). AtlE, ScaA, and ScaB all exhibit human ligand binding capacity. Screening a bank of human serum samples revealed that there were significant increases in the amounts of reactive immunoglobulin G in infected individuals compared to the amounts in healthy individuals for the repeat sequence and mature amidase domains of AtlE, ScaB, and GehD. Vaccination of mice with recombinant antigens stimulated an immune response which in vitro opsonized S. epidermidis. In this study we identified prospective candidate antigens for prophylaxis or immunotherapy to control disease.
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Affiliation(s)
- Mohammad R Pourmand
- Department of Molecular Biology & Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield, S10 2TN, United Kingdom
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24
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Rindi S, Cicalini S, Pietrocola G, Venditti M, Festa A, Foster TJ, Petrosillo N, Speziale P. Antibody response in patients with endocarditis caused by Staphylococcus aureus. Eur J Clin Invest 2006; 36:536-43. [PMID: 16893375 DOI: 10.1111/j.1365-2362.2006.01675.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Staphylococcus aureus expresses a variety of adhesins involved in the colonization of host tissues. This study aimed to evaluate the role of staphylococcal surface proteins in the aetiology of infective endocarditis (IE) and the host immune response to infection. MATERIALS AND METHOD The ELISA assays were used to assess the adherence of S. aureus isolates recovered from the blood cultures of 19 patients with IE (16 were drug abusers) to subendothelial matrix proteins. Anti-adhesin antibody titre was measured incubating surface-coated bacterial antigens with patients' IgG. S. aureus effects on platelet aggregation were evaluated with an aggregometer. RESULTS Staphylococcus aureus isolates, from the patients with IE, exhibited a high expression of several surface components recognizing extracellular matrix proteins: clumping factors A and B (ClfA and ClfB) and fibronectin-binding proteins (FnbpA and FnbpB), whereas only four strains expressed the collagen-binding protein CNA. Bacteria also interacted with platelets both in the absence or presence of fibronectin or fibrinogen and some strongly supported platelet aggregation. Almost all patients presented significantly higher antibody reactivity to ClfA, ClfB, FnbpA, CNA and MAP (MHC class II analogous protein) than in sera from healthy individuals. On the contrary, the reactivity to CNA was remarkable only in three patients. The IgG preparations weakly inhibited the binding of bacteria to fibronectin, whereas they exhibited considerable blocking activity on staphylococcal attachment to fibrinogen or collagen. CONCLUSION Adhesins ClfA, ClfB and FnbpA are produced in vivo and appear important factors both in valve colonization and in promoting host immune responses.
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Affiliation(s)
- S Rindi
- Department of Biochemistry, University of Pavia, Pavia, Italy.
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25
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Kelly-Quintos C, Cavacini LA, Posner MR, Goldmann D, Pier GB. Characterization of the opsonic and protective activity against Staphylococcus aureus of fully human monoclonal antibodies specific for the bacterial surface polysaccharide poly-N-acetylglucosamine. Infect Immun 2006; 74:2742-50. [PMID: 16622211 PMCID: PMC1459728 DOI: 10.1128/iai.74.5.2742-2750.2006] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Carbohydrate antigens are important targets of the immune system in clearing bacterial pathogens. Although the immune system almost exclusively uses antibodies in response to foreign carbohydrates, there is still much to learn about the role of different epitopes on the carbohydrate as targets of protective immunity. We examined the role of acetyl group-dependent and -independent epitopes on the staphylococcal surface of polysaccharide poly-N-acetylated glucosamine (PNAG) by use of human monoclonal antibodies (MAbs) specific for such epitopes. We utilized hybridoma technology to produce fully human immunoglobulin G2 (IgG2) MAbs from B cells of an individual post-Staphylococcus aureus infection and cloned the antibody variable regions to produce an IgG1 form of each original MAb. Specificity and functionality of the purified MAbs were tested in vitro using enzyme-linked immunosorbent assays, complement deposition, and opsonophagocytic assays. We found that a MAb (MAb F598) that bound the best to nonacetylated or backbone epitopes on PNAG had superior complement deposition and opsonophagocytic activity compared to two MAbs that bound optimally to PNAG that was expressed with a native level (>90%) of N-acetyl groups (MAbs F628 and F630). Protection of mice against lethality due to S. aureus strains Mn8 and Reynolds further showed that the backbone-specific MAb had optimal protective efficacy compared with the acetate-specific MAbs. These results provide evidence for the importance of epitope specificity in inducing the optimal protective antibody response to PNAG and indicate that MAbs to the deacetylated form of PNAG could be immunotherapeutic agents for preventing or treating staphylococcal infections.
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Castagliuolo I, Piccinini R, Beggiao E, Palù G, Mengoli C, Ditadi F, Vicenzoni G, Zecconi A. Mucosal genetic immunization against four adhesins protects against Staphylococcus aureus-induced mastitis in mice. Vaccine 2006; 24:4393-402. [PMID: 16580097 DOI: 10.1016/j.vaccine.2006.02.055] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2005] [Revised: 02/01/2006] [Accepted: 02/28/2006] [Indexed: 10/24/2022]
Abstract
Staphylococcus aureus is the most common etiologic agent of mastitis in bovines and a major cause of economic losses in the dairy industry. Since adhesins, that anchor bacteria to the extracellular matrix (ECM), are among the most important S. aureus virulence factors, we used four adhesion factors (fibrinogen binding protein, fibronectin binding protein A, clumping factor A and collagen adhesin) as target in a DNA vaccine. Intranasal immunization with a pDNA mixture coding the four adhesins, triggered significant levels of specific serum and mucosal Ig that inhibited S. aureus adhesion to cow mammary gland epithelial cells in vitro. Splenocytes of immunized mice challenged in vitro with S. aureus extracts showed a strong proliferative response. Finally, immunized mice were significantly protected against intramammary challenge with S. aureus. Our data confirm the feasibility of a genetic mucosal vaccine targeting S. aureus adhesins and prompt further study to test the efficacy in preventing cow mastitis.
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Affiliation(s)
- Ignazio Castagliuolo
- Department of Histology, Microbiology and Medical Biotechnologies, University of Padua, Via Gabelli 63, Padova, Italy
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Abstract
An important facet in the interaction between Staphylococcus aureus and its host is the ability of the bacterium to adhere to human extracellular matrix components and serum proteins. In order to colonise the host and disseminate, it uses a wide range of strategies, the molecular and genetic basis of which are multifactorial, with extensive functional overlap between adhesins. Here, we describe the current knowledge of the molecular features of the adhesive components of S. aureus, mechanisms of adhesion and the impact that these have on host-pathogen interaction.
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Affiliation(s)
- Simon R Clarke
- Department of Molecular Biology & Biotechnology, The University of Sheffield, Firth Court, Western Bank, Sheffield, S10 2TN, UK
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28
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Zong Y, Xu Y, Liang X, Keene DR, Höök A, Gurusiddappa S, Höök M, Narayana SVL. A 'Collagen Hug' model for Staphylococcus aureus CNA binding to collagen. EMBO J 2005; 24:4224-36. [PMID: 16362049 PMCID: PMC1356329 DOI: 10.1038/sj.emboj.7600888] [Citation(s) in RCA: 171] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2005] [Accepted: 11/04/2005] [Indexed: 11/09/2022] Open
Abstract
The structural basis for the association of eukaryotic and prokaryotic protein receptors and their triple-helical collagen ligand remains poorly understood. Here, we present the crystal structures of a high affinity subsegment of the Staphylococcus aureus collagen-binding CNA as an apo-protein and in complex with a synthetic collagen-like triple helical peptide. The apo-protein structure is composed of two subdomains (N1 and N2), each adopting a variant IgG-fold, and a long linker that connects N1 and N2. The structure is stabilized by hydrophobic inter-domain interactions and by the N2 C-terminal extension that complements a beta-sheet on N1. In the ligand complex, the collagen-like peptide penetrates through a spherical hole formed by the two subdomains and the N1-N2 linker. Based on these two structures we propose a dynamic, multistep binding model, called the 'Collagen Hug' that is uniquely designed to allow multidomain collagen binding proteins to bind their extended rope-like ligand.
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Affiliation(s)
- Yinong Zong
- School of Optometry and Center for Biophysical Sciences and Engineering, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Yi Xu
- Center for Extracellular Matrix Biology, Institute of Biosciences and Technology, Texas A&M University Health Science Center, Houston, TX, USA
| | - Xiaowen Liang
- Center for Extracellular Matrix Biology, Institute of Biosciences and Technology, Texas A&M University Health Science Center, Houston, TX, USA
| | | | - Agneta Höök
- Center for Extracellular Matrix Biology, Institute of Biosciences and Technology, Texas A&M University Health Science Center, Houston, TX, USA
| | - Shivasankarappa Gurusiddappa
- Center for Extracellular Matrix Biology, Institute of Biosciences and Technology, Texas A&M University Health Science Center, Houston, TX, USA
| | - Magnus Höök
- Center for Extracellular Matrix Biology, Institute of Biosciences and Technology, Texas A&M University Health Science Center, Houston, TX, USA
- Center for Extracellular Matrix Biology, Institute of Biosciences and Technology, Texas A&M University Health Science Center, 2121 W. Holcombe Blvd, Houston, TX 77030-3303, USA. Tel.: +1 713 677 7552; Fax: +1 713 677 7576; E-mail:
| | - Sthanam V L Narayana
- School of Optometry and Center for Biophysical Sciences and Engineering, University of Alabama at Birmingham, Birmingham, AL, USA
- Center for Biophysical Sciences and Engineering, School of Optometry, University of Alabama at Birmingham, 1025 18th Street South, Birmingham, AL 35294, USA. Tel.: +1 205 934 0119; Fax: +1 205 975 0538; E-mail:
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29
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Maira-Litrán T, Kropec A, Goldmann DA, Pier GB. Comparative opsonic and protective activities of Staphylococcus aureus conjugate vaccines containing native or deacetylated Staphylococcal Poly-N-acetyl-beta-(1-6)-glucosamine. Infect Immun 2005; 73:6752-62. [PMID: 16177353 PMCID: PMC1230901 DOI: 10.1128/iai.73.10.6752-6762.2005] [Citation(s) in RCA: 144] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2005] [Revised: 03/30/2005] [Accepted: 05/18/2005] [Indexed: 11/20/2022] Open
Abstract
Staphylococcus aureus and Staphylococcus epidermidis both synthesize the surface polysaccharide poly-N-acetyl-beta-(1-6)-glucosamine (PNAG), which is produced in vitro with a high level (>90%) of the amino groups substituted by acetate. Here, we examined the role of the acetate substituents of PNAG in generating opsonic and protective antibodies. PNAG and a deacetylated form of the antigen (dPNAG; 15% acetylation) were conjugated to the carrier protein diphtheria toxoid (DT) and used to immunize animals. Mice responded in a dose-dependent fashion to both conjugate vaccines, with maximum antibody titers observed at the highest dose and 4 weeks after the last of three weekly immunizations. PNAG-DT and dPNAG-DT vaccines were also very immunogenic in rabbits. Antibodies raised to the conjugate vaccines in rabbits mediated the opsonic killing of various staphylococcal strains, but the specificity of the opsonic killing was primarily to dPNAG, as this antigen inhibited the killing of S. aureus strains by both PNAG- and dPNAG-specific antibodies. Passive immunization of mice with anti-dPNAG-DT rabbit sera showed significant levels of clearance of S. aureus from the blood (54 to 91%) compared to control mice immunized with normal rabbit sera, whereas PNAG-specific antibodies were ineffective at clearing S. aureus. Passive immunization of mice with a goat antiserum raised to the dPNAG-DT vaccine protected against a lethal dose of three different S. aureus strains. Overall, these data show that immunization of animals with a conjugate vaccine of dPNAG elicit antibodies that mediated opsonic killing and protected against S. aureus infection, including capsular polysaccharide types 5 and 8 and an untypable strain.
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Affiliation(s)
- Tomás Maira-Litrán
- Channing Laboratory, Department of Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA.
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30
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D'Angelo A, Geroldi D, Hancock MA, Valtulina V, Cornaglia AI, Spencer CA, Emanuele E, Calligaro A, Koschinsky ML, Speziale P, Visai L. The apolipoprotein(a) component of lipoprotein(a) mediates binding to laminin: contribution to selective retention of lipoprotein(a) in atherosclerotic lesions. Biochim Biophys Acta Mol Cell Biol Lipids 2005; 1687:1-10. [PMID: 15708348 DOI: 10.1016/j.bbalip.2004.10.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2004] [Revised: 10/08/2004] [Accepted: 10/14/2004] [Indexed: 11/16/2022]
Abstract
Lipoprotein(a) [Lp(a)] entrapment by vascular extracellular matrix may be important in atherogenesis. We sought to determine whether laminin, a major component of the basal membrane, may contribute to Lp(a) retention in the arterial wall. First, immunohistochemistry experiments were performed to examine the relative distribution of Lp(a) and laminin in human carotid artery specimens. There was a high degree of co-localization of Lp(a) and laminin in atherosclerotic specimens, but not in non-atherosclerotic sections. We then studied the binding interaction between Lp(a) and laminin in vitro. ELISA experiments showed that native Lp(a) particles and 17K and 12K recombinant apolipoprotein(a) [r-apo(a)] variants interacted strongly with laminin whereas LDL, apoB-100, and the truncated KIV(6-P), KIV(8-P), and KIV(9-P) r-apo(a) variants did not. Overall, the ELISA data demonstrated that Lp(a) binding to laminin is mediated by apo(a) and a combination of the lysine analogue epsilon-aminocaproic acid and salt effectively decreases apo(a) binding to laminin. Secondary binding analyses with 125I-labeled r-apo(a) revealed equilibrium dissociation constants (K(d)) of 180 and 360 nM for the 17K and 12K variants binding to laminin, respectively. Such similar K(d) values between these two r-apo(a) variants suggest that isoform size does not appear to influence apo(a) binding to laminin. In summary, our data suggest that laminin may bind to apo(a) in the atherosclerotic intima, thus contributing to the selective retention of Lp(a) in this milieu.
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Affiliation(s)
- Angela D'Angelo
- Molecular Medicine Laboratory, University of Pavia, IRCCS Policlinico San Matteo, Piazzale Golgi 2, Pavia, Italy
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31
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Xu Y, Liang X, Chen Y, Koehler TM, Höök M. Identification and biochemical characterization of two novel collagen binding MSCRAMMs of Bacillus anthracis. J Biol Chem 2004; 279:51760-8. [PMID: 15456768 DOI: 10.1074/jbc.m406417200] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cell wall-anchored proteins play critical roles in the pathogenesis of infections caused by Gram-positive bacteria. Through the analysis of the genome of Bacillus anthracis Ames strain, we identified two novel putative cell wall-anchored proteins, BA0871 and BA5258, which have sequence homology to CNA, a cell wall-anchored collagen adhesin of Staphylococcus aureus. The two proteins have similar domain organization to that of CNA, with typical signal peptide sequences, a non-repetitive A region followed by repeats, and a characteristic cell wall-anchoring region. They are expressed on the surface of B. anthracis. The A regions of the two proteins were predicted to adopt similar structural folds as CNA. Circular dichroism analysis of the recombinant A regions of the two proteins (rBA0871A and rBA5258A) indicate that their secondary structure compositions are similar to those of the A regions of CNA and other cell wall-anchored adhesins. We demonstrate through solid phase binding assays and surface plasmon resonance analyses that rBA0871A and rBA5258A specifically bound type I collagen in a dose-dependent and saturable manner. Their dissociation constants (KD) for collagen are 1.6-3.2 microm for rBA0871A and 0.6-0.9 microm for rBA5258A, respectively. We further demonstrate that BA0871 and BA5258 can mediate cell attachment to collagen when expressed on the surface of a heterologous host bacterium. To our knowledge these are the first two adhesins of B. anthracis described, which may have important implications for our understanding of the pathogenic mechanisms explored by this organism.
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Affiliation(s)
- Yi Xu
- The Center for Extracellular Matrix Biology, Texas A&M University System Health Science Center, Albert B. Alkek Institute of Biosciences and Technology, Houston, Texas 77030, USA.
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Pietrocola G, Schubert A, Visai L, Torti M, Fitzgerald JR, Foster TJ, Reinscheid DJ, Speziale P. FbsA, a fibrinogen-binding protein from Streptococcus agalactiae, mediates platelet aggregation. Blood 2004; 105:1052-9. [PMID: 15383464 DOI: 10.1182/blood-2004-06-2149] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The bacterium Streptococcus agalactiae is an etiologic agent in the pathogenesis of endocarditis in humans. FbsA, a fibrinogen-binding protein produced by this pathogen, is considered an important virulence factor. In the present study we provide evidence that S agalactiae clinical isolates bearing FbsA attach to fibrinogen and elicit a fibrinogen-dependent aggregation of platelets. Mutants of S agalactiae lacking the fbsA gene lost the ability to attach to fibrinogen and to aggregate platelets. Plasmid-mediated expression of fbsA restored the capability for fibrinogen binding and platelet aggregation in S agalactiae fbsA mutants, and allowed Lactococcus lactis to interact with fibrinogen and to aggregate human platelets. Moreover, a monoclonal anti-FbsA antibody inhibited bacterial adherence to fibrinogen and S agalactiae-induced platelet aggregation. Platelet aggregation was inhibited by aspirin, prostaglandin E(1,) the peptide RGDS, and the antibody abciximab, demonstrating the specificity of platelet aggregation by S agalactiae and indicating an involvement of integrin glycoprotein IIb/IIIa in the induction of platelet aggregation. Aggregation was also dependent on anti-FbsA IgG and could be inhibited by an antibody against the platelet FcgammaRIIA receptor. These findings indicate that FbsA is a crucial factor in S agalactiae-induced platelet aggregation and may therefore play an important role in S agalactiae-induced endocarditis.
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Affiliation(s)
- Giampiero Pietrocola
- University of Pavia, Department of Biochemistry, Viale Taramelli 3/B 27100 Pavia, Italy
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33
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Fenoglio C, Visai L, Addario C, Gerzeli G, Milanesi G, Vaccarone R, Barni S. Expression of natriuretic peptides, nitric oxide synthase, and guanylate cyclase activity in frog mesonephros during the annual cycle. Gen Comp Endocrinol 2004; 137:166-76. [PMID: 15158128 DOI: 10.1016/j.ygcen.2004.03.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2003] [Revised: 02/17/2004] [Accepted: 03/10/2004] [Indexed: 11/21/2022]
Abstract
Natriuretic peptides (NPs), a family of structurally related hormones and nitric oxide (NO), generated by nitric oxide synthase (NOS), are believed to be involved in the regulation of fluid balance and sodium homeostasis. Differential expression and regulation of these factors depend on both physiological and pathological conditions. Both NPs and NO act in target organs through the activation of guanylate cyclase (GC) and the generation of guanosine 3',5'-cyclic monophosphate (cGMP), which is considered a common messenger for the action of these factors. The present study was designed to investigate--by histochemical methods--the expression of some NPs (proANP and ANP) and isoforms of NOS (neuronal NOS, nNOS, and inducible NOS, iNOS) in the mesonephros of Rana esculenta in different periods of the year including hibernation, to evaluate possible seasonal changes in their expression. We also studied the enzyme activity of NOS-related nicotinamide adenine dinucleotide phosphate diaphorase (NADPHd) and of GC. The experiments were performed on pieces of kidney of R. esculenta collected in their natural environment during active and hibernating life. The study was carried out using immunohistochemical techniques to demonstrate proANP, ANP, and some NOS isoforms. Antigen capture by enzyme linked immunosorbent assay (ELISA) was also performed to determine the presence of NPs in the frog kidney extract. Enzyme histochemistry was used to demonstrate the NOS-related NADPHd activity at light microscopy; GC activity was visualized at the electron microscope, using cerium as capture agent. The application of the immunohistochemical techniques demonstrated that frog mesonephros tubules express different patterns of distribution and/or expression of ANP and NOS during the annual cycle. Comparing the results obtained on active and hibernating frogs has provided interesting data; the NOS/NADPHd and GC activities showed some variations as well. Furthermore, the presence of NPs in the frog kidney extract was evidenced by dose-dependent response in the ELISA. The data suggest that both ANP and NO are intra-renal paracrine and/or autocrine factors which may modulate the adaptations of frog renal functions to seasonal changes through the action of the cGMP generated from GC activity.
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Affiliation(s)
- Carla Fenoglio
- Dipartimento di Biologia Animale, Università di Pavia, Piazza Botta 10, 27100 Pavia, Italy.
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34
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Heddle C, Nobbs AH, Jakubovics NS, Gal M, Mansell JP, Dymock D, Jenkinson HF. Host collagen signal induces antigen I/II adhesin and invasin gene expression in oral Streptococcus gordonii. Mol Microbiol 2003; 50:597-607. [PMID: 14617182 DOI: 10.1046/j.1365-2958.2003.03711.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Microbial interactions with host molecules, and programmed responses to host environmental stimuli, are critical for colonization and initiation of pathogenesis. Bacteria of the genus Streptococcus are primary colonizers of the human mouth. They express multiple cell-surface adhesins that bind salivary components and other oral bacteria and enable the development of polymicrobial biofilms associated with tooth decay and periodontal disease. However, the mechanisms by which streptococci invade dentine to infect the tooth pulp and periapical tissues are poorly understood. Here we show that production of the antigen I/II (AgI/II) family polypeptide adhesin and invasin SspA in Streptococcus gordonii is specifically upregulated in response to a collagen type I signal, minimally the tri-peptide Gly-Pro-Xaa (where Xaa is hydroxyproline or alanine). Increased AgI/II polypeptide expression promotes bacterial adhesion and extended growth of streptococcal cell chains along collagen type I fibrils that are characteristically found within dentinal tubules. These observations define a new model of host matrix signal-induced tissue penetration by bacteria and open the way for novel therapy opportunities for oral invasive diseases.
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Affiliation(s)
- Catherine Heddle
- Department of Oral and Dental Science, University of Bristol Dental School, Lower Maudlin Street, Bristol BS1 2LY, United Kingdom
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35
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Mascari L, Ymele-Leki P, Eggleton CD, Speziale P, Ross JM. Fluid shear contributions to bacteria cell detachment initiated by a monoclonal antibody. Biotechnol Bioeng 2003; 83:65-74. [PMID: 12740934 DOI: 10.1002/bit.10650] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Receptor-mediated adhesion of bacteria to biological surfaces is a significant step leading to infection. Due to an increase in bacterial antibiotic resistance, novel methods to block and disrupt these specific interactions have gained considerable interest as possible therapeutic strategies. Recently, several monoclonal antibodies specific for the Staphylococcus aureus collagen receptor demonstrated specialized ability to displace attached cells from collagen in static assays. In this study, we experimentally examine the monoclonal antibody detachment functionality under physiological shear conditions to evaluate the role of this parameter in the detachment process. The detachment of staphylococci from collagen was quantified in real-time using a parallel plate flow chamber, phase contrast video-microscopy and digital image processing. The results demonstrate a unimodal dependence of detachment on fluid wall shear rate. The observed decrease in effective detachment rate with increasing force at the highest shear levels evaluated is counterintuitive and has not been previously demonstrated. Several possible mechanisms of this result are discussed.
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Affiliation(s)
- Lisa Mascari
- Department of Chemical and Biochemical Engineering, University of Maryland Baltimore County, 1000 Hilltop Circle, ECS 101, Baltimore, Maryland 21250, USA
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36
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Roche FM, Massey R, Peacock SJ, Day NPJ, Visai L, Speziale P, Lam A, Pallen M, Foster TJ. Characterization of novel LPXTG-containing proteins of Staphylococcus aureus identified from genome sequences. MICROBIOLOGY (READING, ENGLAND) 2003; 149:643-654. [PMID: 12634333 DOI: 10.1099/mic.0.25996-0] [Citation(s) in RCA: 144] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Twenty-one genes encoding surface proteins belonging to the LPXTG family have been identified by in silico analysis of six Staphylococcus aureus genome sequences. Eleven genes encode previously described proteins, while 10 have not yet been characterized. Of these, eight contain the cell-wall sorting signal LPXTG responsible for covalently anchoring proteins to the cell-wall peptidoglycan. The remaining two, SasF and SasD, harbour a single residue variation in the fourth position of the LPXTG motif (LPXAG). Western blotting of lysostaphin-solubilized S. aureus cell-wall proteins demonstrated the release of SasF in the cell-wall fraction, indicating that proteins carrying LPXAG are sorted normally. Analysis of primary sequences of the Staphylococcus aureus surface (Sas) proteins indicated that several share a similar structural organization and a common signal sequence with previously characterized LPXTG proteins of S. aureus and other Gram-positive cocci. Protein SasG has 128 residue B repeats that are almost identical at the DNA level. PCR analysis indicated that recombinants with repeat length variations are present in the bacterial population whereas they are not detectable in the B-repeat-encoding region of sdrD. The sasG and sasH genes are significantly associated with invasive disease isolates compared to nasal carriage isolates. Several IgG samples purified from patients recovering from S. aureus infections had higher titres against Sas proteins than control IgG, suggesting that expression occurred during infection in some patients.
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Affiliation(s)
- Fiona M Roche
- Department of Microbiology, Moyne Institute of Preventive Medicine, Trinity College, Dublin 2, Ireland
| | - Ruth Massey
- Nuffield Department of Clinical Laboratory Sciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - Sharon J Peacock
- Nuffield Department of Clinical Laboratory Sciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - Nicholas P J Day
- Nuffield Department of Clinical Laboratory Sciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - Livia Visai
- Department of Biochemistry, University of Pavia, 27100 Pavia, Italy
| | - Pietro Speziale
- Department of Biochemistry, University of Pavia, 27100 Pavia, Italy
| | - Alex Lam
- Department of Microbiology and Immunobiology, The Queen's University of Belfast, Grosvenor Road, Belfast BT12 6BN, UK
| | - Mark Pallen
- Department of Microbiology and Immunobiology, The Queen's University of Belfast, Grosvenor Road, Belfast BT12 6BN, UK
| | - Timothy J Foster
- Department of Microbiology, Moyne Institute of Preventive Medicine, Trinity College, Dublin 2, Ireland
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37
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Clarke SR, Harris LG, Richards RG, Foster SJ. Analysis of Ebh, a 1.1-megadalton cell wall-associated fibronectin-binding protein of Staphylococcus aureus. Infect Immun 2002; 70:6680-7. [PMID: 12438342 PMCID: PMC133066 DOI: 10.1128/iai.70.12.6680-6687.2002] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2002] [Revised: 07/29/2002] [Accepted: 08/27/2002] [Indexed: 01/17/2023] Open
Abstract
In order for Staphylococcus aureus to adhere to host extracellular matrix (ECM) substrates, it elicits a wide range of surface proteins. We have characterized a novel approximately 1.1-MDa protein in S. aureus, termed Ebh (for ECM-binding protein homologue), which has homology to other ECM-binding proteins. Ebh consists of several domains, including a large central region with 44 imperfect repeats of 126 amino acids. Expression analysis revealed ebh to be growth phase regulated and repressed by agr. A fragment of the central repeat region of Ebh was cloned, overexpressed, and used in ligand-binding studies to determine Ebh function. The recombinant protein was found to specifically bind human fibronectin. Ebh is produced during human infection since serum samples taken from patients with confirmed S. aureus infections were found to contain anti-Ebh antibodies. Localization studies revealed Ebh to be cell envelope associated and is proposed to form a specialized surface structure involved in cellular adhesion.
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Affiliation(s)
- Simon R Clarke
- Department of Molecular Biology and Biotechnology, University of Sheffield, Western Bank, United Kingdom
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38
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Lee LY, Miyamoto YJ, McIntyre BW, Höök M, McCrea KW, McDevitt D, Brown EL. The Staphylococcus aureus Map protein is an immunomodulator that interferes with T cell–mediated responses. J Clin Invest 2002. [DOI: 10.1172/jci0216318] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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39
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Lee LY, Miyamoto YJ, McIntyre BW, Höök M, McCrea KW, McDevitt D, Brown EL. The Staphylococcus aureus Map protein is an immunomodulator that interferes with T cell-mediated responses. J Clin Invest 2002; 110:1461-71. [PMID: 12438444 PMCID: PMC151818 DOI: 10.1172/jci16318] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Staphylococcus aureus (SA) is an opportunistic pathogen that affects a variety of organ systems and is responsible for many diseases worldwide. SA express an MHC class II analog protein (Map), which may potentiate SA survival by modulating host immunity. We tested this hypothesis in mice by generating Map-deficient SA (Map(-)SA) and comparing disease outcome to wild-type Map(+)SA-infected mice. Map(-)SA-infected mice presented with significantly reduced levels of arthritis, osteomyelitis, and abscess formation compared with control animals. Furthermore, Map(-)SA-infected nude mice developed arthritis and osteomyelitis to a severity similar to Map(+)SA-infected controls, suggesting that T cells can affect disease outcome following SA infection and Map may attenuate cellular immunity against SA. The capacity of Map to alter T cell function was tested more specifically in vitro and in vivo using native and recombinant forms of Map. T cells or mice treated with recombinant Map had reduced T cell proliferative responses and a significantly reduced delayed-type hypersensitivity response to challenge antigen, respectively. These data suggest a role for Map as an immunomodulatory protein that may play a role in persistent SA infections by affecting protective cellular immunity.
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Affiliation(s)
- Lawrence Y Lee
- The Center for Extracellular Matrix Biology, Texas A&M University System Health Science Center, Albert B. Alkek Institute of Biosciences and Technology, Houston, Texas 77030-7552, USA
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40
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Bowden MG, Visai L, Longshaw CM, Holland KT, Speziale P, Hook M. Is the GehD lipase from Staphylococcus epidermidis a collagen binding adhesin? J Biol Chem 2002; 277:43017-23. [PMID: 12218064 DOI: 10.1074/jbc.m207921200] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The opportunistic human pathogen Staphylococcus epidermidis is the major cause of nosocomial biomaterial infections. S. epidermidis has the ability to attach to indwelling materials coated with extracellular matrix proteins such as fibrinogen, fibronectin, vitronectin, and collagen. To identify the proteins necessary for S. epidermidis attachment to collagen, we screened an expression library using digoxigenin-labeled collagen as well as two monoclonal antibodies generated against the Staphylococcus aureus collagen-adhesin, Cna, as probes. These monoclonal antibodies recognize collagen binding epitopes on the surface of S. aureus and S. epidermidis cells. Using this approach, we identified GehD, the extracellular lipase originally found in S. epidermidis 9, as a collagen-binding protein. Despite the monoclonal antibody cross-reactivity, the GehD amino acid sequence and predicted structure are radically different from those of Cna. The mature GehD circular dichroism spectra differs from that of Cna but strongly resembles that of a mammalian cell-surface collagen binding receptor, known as the alpha(1) integrin I domain, suggesting that they have similar secondary structures. The GehD protein is translated as a preproenzyme, secreted, and post-translationally processed into mature lipase. GehD does not have the conserved LPXTG C-terminal motif present in cell wall-anchored proteins, but it can be detected in lysostaphin cell wall extracts. A recombinant version of mature GehD binds to collagens type I, II, and IV adsorbed onto microtiter plates in a dose-dependent saturable manner. Recombinant, mature GehD protein and anti-GehD antibodies can inhibit the attachment of S. epidermidis to immobilized collagen. These results provide evidence that GehD may be a bi-functional molecule, acting not only as a lipase but also as a cell surface-associated collagen adhesin.
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Affiliation(s)
- M Gabriela Bowden
- Institute of Biosciences and Technology, The Texas A & M University System Health Science Center, Houston, Texas 77030, USA
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41
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Ponnuraj K, Xu Y, Moore D, Deivanayagam CCS, Boque L, Hook M, Narayana SVL. Crystallization and preliminary X-ray crystallographic analysis of Ace: a collagen-binding MSCRAMM from Enterococcus faecalis. BIOCHIMICA ET BIOPHYSICA ACTA 2002; 1596:173-6. [PMID: 12007598 DOI: 10.1016/s0167-4838(01)00328-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ace is a collagen-binding bacterial cell surface adhesin from Enterococcus faecalis. The collagen-binding domain of Ace (termed Ace40) and its truncated form Ace19 have been crystallized by the vapor-diffusion hanging-drop method. Ace19 was crystallized in two different crystal forms. A complete 1.65 A data set has been collected on the orthorhombic crystal form with unit cell parameters a=38.43 b=48.91 and c=83.73 A. Ace40 was crystallized in the trigonal space group P3(1)21 or P3(2)21 with unit cell parameters a=b=80.24, c=105.91 A; alpha=beta=90 and gamma=120 degrees. A full set of X-ray diffraction data was collected to 2.5 A. Three heavy atom derivative data sets have been successfully obtained for Ace19 crystals and structural analysis is in progress.
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Affiliation(s)
- Karthe Ponnuraj
- School of Optometry and Center for Biophysical Sciences and Engineering, University of Alabama at Birmingham, 1025 18th Street South, Birmingham, AL 35294-0005, USA
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42
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Mascari L, Ross JM. Quantifying the temporal expression of the Staphylococcus aureus collagen adhesin. Microb Pathog 2002; 32:99-103. [PMID: 11812215 DOI: 10.1006/mpat.2001.0481] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The initial event in the pathogeneis of most Staphylococcus aureus infections is attachment to biological substrates in vivo using specific protein-protein interactions. We previously quantified the temporal expression of the collagen adhesin (CNA) on S. aureus Phillips and demonstrated that dynamic adhesin capacity to collagen is strongly influenced by the adhesin density. However, most strains of S. aureus express an extensive amount of Protein A on the surface, presenting a complication when using immunofluorescence to quantify specific surface adhesins. In this study, an improved adhesin quantification method is presented that accommodates variable surface Protein A levels. This method was used to examine the temporal expression of CNA on six S. aureus strains. Collagen adhesin levels varied with growth phase and strain, ranging from 1096 to 8950 copies per cell. Five of the six strains exhibited a temporal expression pattern similar to that previously reported for S. aureus Phillips.
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Affiliation(s)
- Lisa Mascari
- Department of Chemical and Biochemical Engineering, University of Maryland, Baltimore County, USA
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43
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Xu Y, Gurusiddappa S, Rich RL, Owens RT, Keene DR, Mayne R, Höök A, Höök M. Multiple binding sites in collagen type I for the integrins alpha1beta1 and alpha2beta1. J Biol Chem 2000; 275:38981-9. [PMID: 10986291 DOI: 10.1074/jbc.m007668200] [Citation(s) in RCA: 192] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Integrins alpha(1)beta(1) and alpha(2)beta(1) are two major collagen receptors on the surface of eukaryotic cells. Binding to collagen is primarily due to an A-domain near the N terminus of the alpha chains. Previously, we reported that recombinant A-domain of alpha(1)beta(1) (alpha(1)A) had at least two affinity classes of binding sites in type I collagen (Rich, R. L., et al. (1999) J. Biol. Chem. 274, 24906-24913). Here, we compared the binding of the recombinant A-domain of alpha(2)beta(1) (alpha(2)A) to type I collagen with that of alpha(1)A using surface plasmon resonance and showed that alpha(2)A exhibited only one detectable class of binding sites in type I collagen, with a K(D) of approximately 10 microm at approximately 3 binding sites per collagen molecule. We further demonstrated that alpha(1)A and alpha(2)A competed with each other for binding to type I collagen in enzyme-linked immunosorbent assay (ELISA), suggesting that the binding sites in collagen for the two A-domains overlap or are adjacent to each other. By using rotary shadowing, the complexes of alpha(1)A- and alpha(2)A-procollagen were visualized. Morphometric analyses indicated three major binding regions (near the N terminus, in the central part, and near the C terminus) along the type I procollagen molecule for both A-domains. The positions of the respective binding regions for alpha(1)A and alpha(2)A were overlapping with or adjacent to each other, consistent with the ELISA results. Analysis of the sequences of type I collagen revealed that GER or GER-like motifs are present at each of the binding regions, and notably, the central region contains the GFOGER sequence, which was previously identified as a high affinity site for both alpha(1)A and alpha(2)A (Knight, C. G., et al. (2000) J. Biol. Chem. 275, 35-40). Peptides containing GLOGERGRO (peptide I, near the N terminus), GFOGERGVQ (peptide II, central), and GASGERGPO (peptide III, near the C terminus) were synthesized. Peptides I and II effectively inhibited the binding of alpha(1)A and alpha(2)A to type I collagen, while peptide III did so moderately. The N-terminal site in type I collagen has the sequence GLOGER in all three chains. Thus, it seems that peptide I represents a newly discovered native high affinity site for alpha(1)A and alpha(2)A.
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Affiliation(s)
- Y Xu
- Center for Extracellular Matrix Biology, Institute of Biosciences and Technology, Texas A & M University, Houston, Texas 77030, USA
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