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Timothy J. Foster - One of the best experts on this subject based on the ideXlab platform.
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Fibronectin Binding Protein b fnbpb from staphylococcus aureus protects against the antimicrobial activity of histones
Journal of Biological Chemistry, 2019Co-Authors: Giampiero Pietrocola, Timothy J. Foster, Joan A. Geoghegan, Giulia Nobile, Mariangela J Alfeo, Vincenzo De Filippis, Pietro SpezialeAbstract:: Staphylococcus aureus is a Gram-positive bacterium that can cause both superficial and deep-seated infections. Histones released by neutrophils kill bacteria by Binding to the bacterial cell surface and causing membrane damage. We postulated that cell wall-anchored Proteins protect S. aureus from the bactericidal effects of histones by Binding to and sequestering histones away from the cell envelope. Here, we focused on S. aureus strain LAC and by using an array of biochemical assays, including surface plasmon resonance and ELISA, discovered that Fibronectin-Binding Protein B (FnBPB) is the main histone receptor. FnBPB bound all types of histones, but histone H3 displayed the highest affinity and bactericidal activity and was therefore investigated further. H3 bound specifically to the A domain of recombinant FnBPB with a KD of 86 nm, ∼20-fold lower than that for fibrinogen. Binding apparently occurred by the same mechanism by which FnBPB binds to fibrinogen, because FnBPB variants defective in fibrinogen Binding also did not bind H3. An FnBPB-deletion mutant of S. aureus LAC bound less H3 and was more susceptible to its bactericidal activity and to neutrophil extracellular traps, whereas an FnBPB-overexpressing mutant bound more H3 and was more resistant than the WT. FnBPB bound simultaneously to H3 and plasminogen, which after activation by tissue plasminogen activator cleaved the bound histone. We conclude that FnBPB provides a dual immune-evasion function that captures histones and prevents them from reaching the bacterial membrane and simultaneously binds plasminogen, thereby promoting its conversion to plasmin to destroy the bound histone.
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molecular interactions of human plasminogen with Fibronectin Binding Protein b fnbpb a fibrinogen Fibronectin Binding Protein from staphylococcus aureus
Journal of Biological Chemistry, 2016Co-Authors: Giampiero Pietrocola, Timothy J. Foster, Joan A. Geoghegan, Giulia Nobile, Valentina Gianotti, Marta Zapotoczna, Pietro SpezialeAbstract:Abstract Staphylococcus aureus is a commensal bacterium that has the ability to cause superficial and deep-seated infections. Like several other invasive pathogens, S. aureus can capture plasminogen from the human host where it can be converted to plasmin by host plasminogen activators or by endogenously expressed staphylokinase. This study demonstrates that sortase-anchored cell wall-associated Proteins are responsible for capturing the bulk of bound plasminogen. Two cell wall-associated Proteins, the fibrinogen- and Fibronectin-Binding Proteins A and B, were found to bind plasminogen, and one of them, FnBPB, was studied in detail. Plasminogen captured on the surface of S. aureus- or Lactococcus lactis-expressing FnBPB could be activated to the potent serine protease plasmin by staphylokinase and tissue plasminogen activator. Plasminogen bound to recombinant FnBPB with a KD of 0.532 μm as determined by surface plasmon resonance. Plasminogen Binding did not to occur by the same mechanism through which FnBPB binds to fibrinogen. Indeed, FnBPB could bind both ligands simultaneously indicating that their Binding sites do not overlap. The N3 subdomain of FnBPB contains the full plasminogen-Binding site, and this includes, at least in part, two conserved patches of surface-located lysine residues that were recognized by kringle 4 of the host Protein.
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Molecular Interactions of Human Plasminogen with Fibronectin-Binding Protein B (FnBPB), a Fibrinogen/Fibronectin-Binding Protein from Staphylococcus aureus.
Journal of Biological Chemistry, 2016Co-Authors: Giampiero Pietrocola, Timothy J. Foster, Joan A. Geoghegan, Giulia Nobile, Valentina Gianotti, Marta Zapotoczna, Pietro SpezialeAbstract:Abstract Staphylococcus aureus is a commensal bacterium that has the ability to cause superficial and deep-seated infections. Like several other invasive pathogens, S. aureus can capture plasminogen from the human host where it can be converted to plasmin by host plasminogen activators or by endogenously expressed staphylokinase. This study demonstrates that sortase-anchored cell wall-associated Proteins are responsible for capturing the bulk of bound plasminogen. Two cell wall-associated Proteins, the fibrinogen- and Fibronectin-Binding Proteins A and B, were found to bind plasminogen, and one of them, FnBPB, was studied in detail. Plasminogen captured on the surface of S. aureus- or Lactococcus lactis-expressing FnBPB could be activated to the potent serine protease plasmin by staphylokinase and tissue plasminogen activator. Plasminogen bound to recombinant FnBPB with a KD of 0.532 μm as determined by surface plasmon resonance. Plasminogen Binding did not to occur by the same mechanism through which FnBPB binds to fibrinogen. Indeed, FnBPB could bind both ligands simultaneously indicating that their Binding sites do not overlap. The N3 subdomain of FnBPB contains the full plasminogen-Binding site, and this includes, at least in part, two conserved patches of surface-located lysine residues that were recognized by kringle 4 of the host Protein.
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Functional analysis of a murine monoclonal antibody against the repetitive region of the Fibronectin-Binding adhesins Fibronectin-Binding Protein A and Fibronectin-Binding Protein B from Staphylococcus aureus
FEBS Journal, 2010Co-Authors: Giulio Provenza, Maria Provenzano, Livia Visai, Fiona M. Burke, Joan A. Geoghegan, Matteo Stravalaci, Marco Gobbi, Giuliano Mazzini, Carla Renata Arciola, Timothy J. FosterAbstract:Fibronectin-Binding Proteins A and B are multifunctional LPXTG staphylococcal adhesins, comprising an N-terminal region that binds fibrinogen and elastin, and a C-terminal domain that interacts with Fibronectin. The C-terminal domain of Fibronectin-Binding Protein A is organized into 11 tandem repeats, six of which bind the ligand with high affinity; other sites bind more weakly. Fibronectin-Binding Protein B has been postulated to harbor 10 rather than 11 repeats, but it contains the same number of high-affinity Fibronectin-Binding sites as Fibronectin-Binding Protein A. In this study, we confirm this prediction and show that six of 10 sites bind with dissociation constants in the nanomolar range. We also found that the full-length repetitive region of Fibronectin-Binding Protein B stimulated the production of a mAb (15E11) that binds with high affinity to an epitope shared by repeats 9 and 10 from both adhesins. With the use of truncated fragments of repeat 9 of Fibronectin-Binding Protein A, we mapped the antibody epitope to the N-terminal segment and the Fibronectin-Binding site to the C-terminal segment of the repeat. The distinct localization of the 15E11 epitope and the Fibronectin-Binding site suggests that the interfering effect of the antibody might result from steric hindrance or a conformational change in the structure that reduces the accessibility of Fibronectin to its Binding determinant. The epitope is well exposed on the surface of staphylococcal cells, as determined by genetic analyses, fluorescence microscopy, and flow cytometry. When incubated with cells of Staphylococcs aureus strains, 15E11 inhibits attachment of bacteria to surface-coated Fibronectin by almost 70%. Structured digital abstract: • MINT-7991189, MINT-7991227, MINT-7991305, MINT-7991292, MINT-7991279, MINT-7991266, MINT-7991253, MINT-7991622: fnbA (uniprotkb:P14738) binds (MI:0407) to Fibronectin (uniprotkb:P02751) by enzyme linked immunosorbent assay (MI:0411) • MINT-7991435, MINT-7991636, MINT-7991447, MINT-7991462, MINT-7991477, MINT-7991492, MINT-7991507, MINT-7991522: fnbA (uniprotkb:P14738) binds (MI:0407) to Fibronectin (uniprotkb:P02751) by filter Binding (MI:0049) • MINT-7991577, MINT-7991594: fnbB (uniprotkb:Q53682) binds (MI:0407) to Fibronectin (uniprotkb:P02751) by surface plasmon resonance (MI:0107) • MINT-7991321, MINT-7991345, MINT-7991360, MINT-7991375, MINT-7991390, MINT-7991405, MINT-7991420: fnbB (uniprotkb:Q53682) binds (MI:0407) to Fibronectin (uniprotkb:P02751) by filter Binding (MI:0049) • MINT-7991103, MINT-7991114, MINT-7991126, MINT-7991138, MINT-7991153, MINT-7991165, MINT-7991177: fnbB (uniprotkb:Q53682) binds (MI:0407) to Fibronectin (uniprotkb:P02751) by enzyme linked immunosorbent assay (MI:0411) • MINT-7991540, MINT-7991558: fnbA (uniprotkb:P14738) binds (MI:0407) to Fibronectin (uniprotkb:P02751) by surface plasmon resonance (MI:0107)
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Fibronectin Binding Protein b variation in staphylococcus aureus
BMC Microbiology, 2010Co-Authors: Fiona M. Burke, Pietro Speziale, Niamh Mccormack, Simonetta Rindi, Timothy J. FosterAbstract:Background Fibronectin Binding Proteins A and B (FnBPA and FnBPB) mediate adhesion of S. aureus to fibrinogen, elastin and Fibronectin. We previously identified seven different isotypes of FnBPA based on divergence in the fibrinogen- and elastin-Binding A domains. The variation created differences in antigenicity while ligand Binding functions were retained. Here, FnBPB variation was examined in both human and bovine isolates and compared to that of FnBPA.
Susanne R. Talay - One of the best experts on this subject based on the ideXlab platform.
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the fbab type Fibronectin Binding Protein of streptococcus pyogenes promotes specific invasion into endothelial cells
Cellular Microbiology, 2011Co-Authors: Silva Amelung, Gursharan S. Chhatwal, Manfred Rohde, A Nerlich, Barbara Spellerberg, Jason N Cole, Victor Nizet, Susanne R. TalayAbstract:Invasive serotype M3 Streptococcus pyogenes are among the most frequently isolated organisms from patients suffering from invasive streptococcal disease and have the potential to invade primary human endothelial cells (EC) via a rapid and efficient mechanism. FbaB Protein, the Fibronectin-Binding Protein expressed by M3 S. pyogenes, was herein identified as a potent invasin for EC. By combining heterologous gene expression with allelic replacement, we demonstrate that FbaB is essential and sufficient to trigger EC invasion via a Rac1-dependent phagocytosis-like uptake. FbaB-mediated uptake follows the classical endocytic pathway with lysosomal destination. FbaB is demonstrated to be a streptococcal invasin exhibiting EC tropism. FbaB thus initiates a process that may contribute to the deep tissue tropism and spread of invasive S. pyogenes isolates into the vascular EC lining.
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Differences in the aromatic domain of homologous streptococcal Fibronectin‐Binding Proteins trigger different cell invasion mechanisms and survival rates
Cellular Microbiology, 2010Co-Authors: Manfred Rohde, Susanne R. Talay, Marcus Fulde, Rikki M. A. Graham, Katja Branitzki-heinemann, Patricia Borchers, Claudia Preuss, Ina Schleicher, Dorothea Zähner, Katrin DinklaAbstract:Summary Group A streptococci (GAS, Streptococcus pyo- genes) and Group G streptococci (GGS, Strepto- coccus dysgalactiae ssp. equisimilis) adhere to and invade host cells by Binding to Fibronectin. The Fibronectin-Binding Protein SfbI from GAS acts as an invasin by using a caveolae-mediated mechanism. In the present study we have identi- fied a Fibronectin-Binding Protein, GfbA, from GGS, which functions as an adhesin and invasin. Although there is a high degree of similarity in the C-terminal sequence of SfbI and GfbA, the invasion mechanisms are different. Unlike caveolae-mediated invasion by SfbI-expressing GAS, the GfbA-expressing GGS isolate trigger cytoskeleton rearrangements. Heterologous ex- pression of GfbA on the surface of a commensal Streptococcus gordonii and purified recombinant Protein also triggered actin rearrangements. Expression of a truncated GfbA (lacking the aro- matic domain) and chimeric GfbA/SfbI Protein (replacing the aromatic domain of SfbI with the GfbA aromatic domain) on S. gordonii or recombi- nant Proteins alone showed that the aromatic domain of GfbA is responsible for different inva- sion mechanisms. This is the first evidence for a biological function of the aromatic domain of Fibronectin-Binding Proteins. Furthermore, we show that streptococci invading via cytoskeleton rearrangements and intracellular trafficking along the classical endocytic pathway are less persis- tence than streptococci entering via caveolae.
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protective immune response against streptococcus pyogenes in mice after intranasal vaccination with the Fibronectin Binding Protein sfbi
The Journal of Infectious Diseases, 1999Co-Authors: Carlos A. Guzmán, Susanne R. Talay, Gabriella Molinari, Eva Medina, Gursharan S. ChhatwalAbstract:Despite the significant impact on human health of Streptococcus pyogenes, an efficacious vaccine has not yet been developed. Here, the potential as a vaccine candidate of a major streptococcal adhesin, the Fibronectin-Binding Protein SfbI, was evaluated. Intranasal immunization of mice with either SfbI alone or coupled to cholera toxin B subunit (CTB) triggered efficient SfbI-specific humoral (mainly IgG) and lung mucosal (14% of total IgA) responses. CTB-immunized control mice were not protected against challenge with S. pyogenes (90%‐100% lethality), whereas SfbI-vaccinated animals showed 80% and 90% protection against homologous and heterologous challenge, respectively. Multiple areas of consolidation with diffused cellular infiltrates (macrophages and neutrophils) were observed in lungs from control mice; the histologic structure was preserved in SfbI-vaccinated animals, which occasionally presented focal infiltrates confined to the perivascular, peribronchial, and subpleural areas. These results suggest that SfbI is a promising candidate for inclusion in acellular vaccines against S. pyogenes. Streptococcus pyogenes (group A Streptococcus) is a human pathogenic microorganism capable of causing a wide range of diseases [1]. The clinical presentation varies from localized infections, such as pharyngitis and pyoderma, to highly invasive diseases, such as sepsis, necrotizing fasciitis, and toxic shock‐like syndrome. These infections can lead to the development of severe sequelae, such as rheumatic fever with carditis and acute poststreptococcal glomerulonephritis. In recent years, a resurgence in the rates of S. pyogenes infections and their sequelae has been observed worldwide [2, 3]. Streptococcal infections are also endemic in certain communities, such as aboriginal populations in the Australian Northern Territory and schoolchildren in north India [4, 5]. Of interest, despite the high rates of rheumatic fever and acute poststreptococcal glomerulonephritis reported in these communities, the incidence of invasive disease has been relatively low.
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the Fibronectin Binding Protein of streptococcus pyogenes sfbi is involved in the internalization of group a streptococci by epithelial cells
Infection and Immunity, 1997Co-Authors: Gabriella Molinari, Susanne R. Talay, Peter Valentinweigand, Manfred Rohde, G S ChhatwalAbstract:Streptococcus pyogenes organisms (group A streptococci) are considered to be highly adhesive extracellular pathogens. However, it has recently been reported that S. pyogenes has the capacity to efficiently invade eukaryotic cells. In this study, we demonstrate that the interaction of S. pyogenes Fibronectin-Binding Protein (SfbI) with Fibronectin on nonphagocytic HEp-2 cells triggers bacterial internalization. Blocking of the SfbI adhesin by either antibodies against the whole Protein or antibodies against the Fibronectin-Binding domains of SfbI, as well as pretreatment of HEp-2 cells with purified SfbI Protein, prevents both S. pyogenes attachment and internalization. Inert latex beads precoated with the purified SfbI Protein are ingested by eukaryotic cells, demonstrating that SfbI is per se enough to trigger the internalization process. Experiments performed with a recombinant SfbI domain encompassing the two Fibronectin-Binding regions of the SfbI molecule demonstrated that these Binding regions are essential and sufficient to activate uptake by HEp-2 cells. These results demonstrate that the Fibronectin-Binding Protein SfbI is involved in both S. pyogenes' attachment to and ingestion by HEp-2 cells and contribute to elucidation of the underlying molecular events leading to eukaryotic cell invasion by S. pyogenes.
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Identification of a Fibronectin-Binding Protein as adhesin of Streptococcus pyogenes.
Zentralblatt Fur Bakteriologie-international Journal of Medical Microbiology Virology Parasitology and Infectious Diseases, 1993Co-Authors: Peter Valentin-weigand, Susanne R. Talay, Kenneth N. Timmis, Gursharan S. ChhatwalAbstract:Summary The role of streptococcal Fibronectin-Binding Protein (Sfb Protein) in the adherence of Streptococcus pyogenes to epithelial cells was analyzed by using a recombinant Sfb fusion Protein which was constructed by fusion of the Binding domain of Sfb Protein to MS2 polymerase. Sfb fusion Protein was overexpressed in Escherichia coli , purified from E. coli lysates by FPLC and analysed in Binding experiments with 125 I-Iabelled Fibronectin and adherence studies with HEp2 epithelial cells. Lysates from E. coli expressing the fusion Protein as well as purified Sfb Protein competitively inhibited Fibronectin Binding and epithelial cell adherence of S. pyogenes , whereas streptococcal lipoteichoic acid (LTA), previously suggested to be the adhesin of S. pyogenes , had no effects. Southern blot analysis of chromosomal DNA from various streptococci revealed that the gene coding for the Binding domain of Sfb Protein was also present in other S. pyogenes strains. These results indicate that Fibronectin-Binding Protein is the major adhesin of S. pyogenes .
Gursharan S. Chhatwal - One of the best experts on this subject based on the ideXlab platform.
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the fbab type Fibronectin Binding Protein of streptococcus pyogenes promotes specific invasion into endothelial cells
Cellular Microbiology, 2011Co-Authors: Silva Amelung, Gursharan S. Chhatwal, Manfred Rohde, A Nerlich, Barbara Spellerberg, Jason N Cole, Victor Nizet, Susanne R. TalayAbstract:Invasive serotype M3 Streptococcus pyogenes are among the most frequently isolated organisms from patients suffering from invasive streptococcal disease and have the potential to invade primary human endothelial cells (EC) via a rapid and efficient mechanism. FbaB Protein, the Fibronectin-Binding Protein expressed by M3 S. pyogenes, was herein identified as a potent invasin for EC. By combining heterologous gene expression with allelic replacement, we demonstrate that FbaB is essential and sufficient to trigger EC invasion via a Rac1-dependent phagocytosis-like uptake. FbaB-mediated uptake follows the classical endocytic pathway with lysosomal destination. FbaB is demonstrated to be a streptococcal invasin exhibiting EC tropism. FbaB thus initiates a process that may contribute to the deep tissue tropism and spread of invasive S. pyogenes isolates into the vascular EC lining.
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protective immune response against streptococcus pyogenes in mice after intranasal vaccination with the Fibronectin Binding Protein sfbi
The Journal of Infectious Diseases, 1999Co-Authors: Carlos A. Guzmán, Susanne R. Talay, Gabriella Molinari, Eva Medina, Gursharan S. ChhatwalAbstract:Despite the significant impact on human health of Streptococcus pyogenes, an efficacious vaccine has not yet been developed. Here, the potential as a vaccine candidate of a major streptococcal adhesin, the Fibronectin-Binding Protein SfbI, was evaluated. Intranasal immunization of mice with either SfbI alone or coupled to cholera toxin B subunit (CTB) triggered efficient SfbI-specific humoral (mainly IgG) and lung mucosal (14% of total IgA) responses. CTB-immunized control mice were not protected against challenge with S. pyogenes (90%‐100% lethality), whereas SfbI-vaccinated animals showed 80% and 90% protection against homologous and heterologous challenge, respectively. Multiple areas of consolidation with diffused cellular infiltrates (macrophages and neutrophils) were observed in lungs from control mice; the histologic structure was preserved in SfbI-vaccinated animals, which occasionally presented focal infiltrates confined to the perivascular, peribronchial, and subpleural areas. These results suggest that SfbI is a promising candidate for inclusion in acellular vaccines against S. pyogenes. Streptococcus pyogenes (group A Streptococcus) is a human pathogenic microorganism capable of causing a wide range of diseases [1]. The clinical presentation varies from localized infections, such as pharyngitis and pyoderma, to highly invasive diseases, such as sepsis, necrotizing fasciitis, and toxic shock‐like syndrome. These infections can lead to the development of severe sequelae, such as rheumatic fever with carditis and acute poststreptococcal glomerulonephritis. In recent years, a resurgence in the rates of S. pyogenes infections and their sequelae has been observed worldwide [2, 3]. Streptococcal infections are also endemic in certain communities, such as aboriginal populations in the Australian Northern Territory and schoolchildren in north India [4, 5]. Of interest, despite the high rates of rheumatic fever and acute poststreptococcal glomerulonephritis reported in these communities, the incidence of invasive disease has been relatively low.
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Identification of a Fibronectin-Binding Protein as adhesin of Streptococcus pyogenes.
Zentralblatt Fur Bakteriologie-international Journal of Medical Microbiology Virology Parasitology and Infectious Diseases, 1993Co-Authors: Peter Valentin-weigand, Susanne R. Talay, Kenneth N. Timmis, Gursharan S. ChhatwalAbstract:Summary The role of streptococcal Fibronectin-Binding Protein (Sfb Protein) in the adherence of Streptococcus pyogenes to epithelial cells was analyzed by using a recombinant Sfb fusion Protein which was constructed by fusion of the Binding domain of Sfb Protein to MS2 polymerase. Sfb fusion Protein was overexpressed in Escherichia coli , purified from E. coli lysates by FPLC and analysed in Binding experiments with 125 I-Iabelled Fibronectin and adherence studies with HEp2 epithelial cells. Lysates from E. coli expressing the fusion Protein as well as purified Sfb Protein competitively inhibited Fibronectin Binding and epithelial cell adherence of S. pyogenes , whereas streptococcal lipoteichoic acid (LTA), previously suggested to be the adhesin of S. pyogenes , had no effects. Southern blot analysis of chromosomal DNA from various streptococci revealed that the gene coding for the Binding domain of Sfb Protein was also present in other S. pyogenes strains. These results indicate that Fibronectin-Binding Protein is the major adhesin of S. pyogenes .
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Fibronectin Binding Protein of streptococcus pyogenes sequence of the Binding domain involved in adherence of streptococci to epithelial cells
Infection and Immunity, 1992Co-Authors: Susanne R. Talay, Kenneth N. Timmis, Peter Valentinweigand, P G Jerlstrom, Gursharan S. ChhatwalAbstract:The sequence of the Fibronectin-Binding domain of the Fibronectin-Binding Protein of Streptococcus pyogenes (Sfb Protein) was determined, and its role in streptococcal adherence was investigated by use of an Sfb fusion Protein in adherence studies. A 1-kb DNA fragment coding for the Binding domain of Sfb Protein was cloned into the expression vector pEX31 to produce an Sfb fusion Protein consisting of the N-terminal part of MS2 polymerase and a C-terminal fragment of the streptococcal Protein. Induction of the vector promoter resulted in hyperexpression of Fibronectin-Binding fusion Protein in the cytoplasm of the recombinant Escherichia coli cells. Sequence determination of the cloned 1-kb fragment revealed an in-frame reading frame for a 268-amino-acid peptide composed of a 37-amino-acid sequence which is completely repeated three times and incompletely repeated a fourth time. Cloning of one repeat into pEX31 resulted in expression of small fusion peptides that show Fibronectin-Binding activity, indicating that one repeat contains at least one Binding domain. Each repeat exhibits two charged domains and shows high homology with the 38-amino-acid D3 repeat of the Fibronectin-Binding Protein of Staphylococcus aureus. Sequence comparison with other streptococcal ligand-Binding surface Proteins, including M Protein, failed to reveal significant homology, which suggests that Sfb Protein represents a novel type of functional Protein in S. pyogenes. The Sfb fusion Protein isolated from the cytoplasm of recombinant cells was purified by fast Protein liquid chromatography. It showed a strong competitive inhibition of Fibronectin Binding to S. pyogenes and of the adherence of bacteria to cultured epithelial cells. In contrast, purified streptococcal lipoteichoic acid showed only a weak inhibition of Fibronectin Binding and streptococcal adherence. These results demonstrate that Sfb Protein is directly involved in the Fibronectin-mediated adherence of S. pyogenes to epithelial cells. Images
Victor Nizet - One of the best experts on this subject based on the ideXlab platform.
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the fbab type Fibronectin Binding Protein of streptococcus pyogenes promotes specific invasion into endothelial cells
Cellular Microbiology, 2011Co-Authors: Silva Amelung, Gursharan S. Chhatwal, Manfred Rohde, A Nerlich, Barbara Spellerberg, Jason N Cole, Victor Nizet, Susanne R. TalayAbstract:Invasive serotype M3 Streptococcus pyogenes are among the most frequently isolated organisms from patients suffering from invasive streptococcal disease and have the potential to invade primary human endothelial cells (EC) via a rapid and efficient mechanism. FbaB Protein, the Fibronectin-Binding Protein expressed by M3 S. pyogenes, was herein identified as a potent invasin for EC. By combining heterologous gene expression with allelic replacement, we demonstrate that FbaB is essential and sufficient to trigger EC invasion via a Rac1-dependent phagocytosis-like uptake. FbaB-mediated uptake follows the classical endocytic pathway with lysosomal destination. FbaB is demonstrated to be a streptococcal invasin exhibiting EC tropism. FbaB thus initiates a process that may contribute to the deep tissue tropism and spread of invasive S. pyogenes isolates into the vascular EC lining.
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molecular genetic analysis of a group a streptococcus operon encoding serum opacity factor and a novel Fibronectin Binding Protein sfbx
Journal of Bacteriology, 2003Co-Authors: Arthur Jeng, Varja Sakota, Zhongya Li, Vivekananda Datta, Bernard Beall, Victor NizetAbstract:The group A Streptococcus (GAS) sof gene encodes the serum opacity factor Protein, which is capable of opacifying mammalian sera and Binding at least two host Proteins, Fibronectin and fibrinogen. The sof gene exists in approximately 50% of clinical isolates, and there is a classical association of so-called nephritogenic strains with the opacity factor-positive phenotype. In both a type emm49 strain and a type emm12 strain, the sequences upstream of the 5′ end of sof and downstream of the putative terminator were determined to be nearly identical to a region in the M type 1 genome approximately 10 kb upstream of the emm1 gene. This close genetic linkage is likely reflected in the strict correlation of opacity factor phenotype with specific emm genotypes. A new Fibronectin-Binding Protein gene, sfbX, was discovered immediately downstream of sof in emm12 and emm49 strains and in several other sof-positive strains. The sof and sfbX genes were found to be expressed on the same transcription unit, which was correlated with the putative promoter and rho-independant terminator sequences that flank these two genes. The sfbX genes from different emm types are predicted to encode ∼650-residue surface-bound Proteins sharing 89 to 92% sequence identity. SfbX residues approximately 1 to 480 are not highly similar to those of other known Proteins, with the closest match being the Staphylococcus aureus coagulase Protein. The remaining portions of these Proteins (residues 481 to 650) contain four putative Fibronectin-Binding repeats highly similar to those of other streptococcal Fibronectin-Binding Proteins and a potential LP(X)SG cell wall anchor motif. Targeted in-frame allelic-exchange mutagenesis, complementation, and heterologous-expression studies found that serum opacification is encoded by sof alone and that sfbX encodes a Fibronectin-Binding function. A recombinant SfbX Protein was found to bind immobilized Fibronectin and to partially inhibit GAS adherence to Fibronectin. The sfbX gene was found to be present only in sof-positive strains, and together these genes could influence the spectrum of tissues colonized by sof-positive GAS.
Xin Zhao - One of the best experts on this subject based on the ideXlab platform.
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a Fibronectin Binding Protein fbpa of weissella cibaria inhibits colonization and infection of staphylococcus aureus in mammary glands
Cellular Microbiology, 2017Co-Authors: Liangliang Wang, Wei Si, Xin ZhaoAbstract:: Staphylococcus aureus (S. aureus) is a frequent cause of infections in both humans and animals. Probiotics are known to inhibit colonization of pathogens on host tissues. However, mechanisms for the inhibition are still elusive due to complex host-microbe and microbe-microbe interactions. Here, we show that reduced abilities of S. aureus to infect mammary glands in the presence of Weissella cibaria (W. cibaria) were correlated with its poor adherence to mammary epithelial cells. Such inhibition by W. cibaria isolates was at least partially attributed to a Fibronectin-Binding Protein (FbpA) on this lactic acid bacterium. Three W. cibaria isolates containing fbpA had higher inhibitory abilities than other three LAB isolates without the gene. The fbpA-deficient mutant of W. cibaria isolate LW1, LW1ΔfbpA, lost the inhibitory activity to reduce the adhesion of S. aureus to mammary epithelial cells and was less able to reduce the colonization of S. aureus in mammary glands. Expression of FbpA to the surface of LW1ΔfbpA reversed its inhibitory activities. Furthermore, addition of purified FbpA inhibited S. aureus biofilm formation. Our results suggest that W. cibaria FbpA hinders S. aureus colonization and infection through interfering with the S. aureus invasion pathway mediated by Fibronectin-Binding Proteins and inhibiting biofilm formation of S. aureus.
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A Fibronectin‐Binding Protein (FbpA) of Weissella cibaria inhibits colonization and infection of Staphylococcus aureus in mammary glands
Cellular Microbiology, 2017Co-Authors: Liangliang Wang, Wei Si, Xin ZhaoAbstract:: Staphylococcus aureus (S. aureus) is a frequent cause of infections in both humans and animals. Probiotics are known to inhibit colonization of pathogens on host tissues. However, mechanisms for the inhibition are still elusive due to complex host-microbe and microbe-microbe interactions. Here, we show that reduced abilities of S. aureus to infect mammary glands in the presence of Weissella cibaria (W. cibaria) were correlated with its poor adherence to mammary epithelial cells. Such inhibition by W. cibaria isolates was at least partially attributed to a Fibronectin-Binding Protein (FbpA) on this lactic acid bacterium. Three W. cibaria isolates containing fbpA had higher inhibitory abilities than other three LAB isolates without the gene. The fbpA-deficient mutant of W. cibaria isolate LW1, LW1ΔfbpA, lost the inhibitory activity to reduce the adhesion of S. aureus to mammary epithelial cells and was less able to reduce the colonization of S. aureus in mammary glands. Expression of FbpA to the surface of LW1ΔfbpA reversed its inhibitory activities. Furthermore, addition of purified FbpA inhibited S. aureus biofilm formation. Our results suggest that W. cibaria FbpA hinders S. aureus colonization and infection through interfering with the S. aureus invasion pathway mediated by Fibronectin-Binding Proteins and inhibiting biofilm formation of S. aureus.