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Torres-Sangiao E, Happonen L, Heusel M, Palm F, Gueto-Tettay C, Malmström L, Shannon O, Malmström J. Quantification of Adaptive Immune Responses Against Protein-Binding Interfaces in the Streptococcal M1 Protein. Mol Cell Proteomics 2024; 23:100753. [PMID: 38527648 PMCID: PMC11059317 DOI: 10.1016/j.mcpro.2024.100753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 02/28/2024] [Accepted: 03/22/2024] [Indexed: 03/27/2024] Open
Abstract
Bacterial or viral antigens can contain subdominant protein regions that elicit weak antibody responses upon vaccination or infection although there is accumulating evidence that antibody responses against subdominant regions can enhance the protective immune response. One proposed mechanism for subdominant protein regions is the binding of host proteins that prevent antibody production against epitopes hidden within the protein binding interfaces. Here, we used affinity purification combined with quantitative mass spectrometry (AP-MS) to examine the level of competition between antigen-specific antibodies and host-pathogen protein interaction networks using the M1 protein from Streptococcus pyogenes as a model system. As most humans have circulating antibodies against the M1 protein, we first used AP-MS to show that the M1 protein interspecies protein network formed with human plasma proteins is largely conserved in naïve mice. Immunizing mice with the M1 protein generated a time-dependent increase of anti-M1 antibodies. AP-MS analysis comparing the composition of the M1-plasma protein network from naïve and immunized mice showed significant enrichment of 292 IgG peptides associated with 56 IgG chains in the immune mice. Despite the significant increase of bound IgGs, the levels of interacting plasma proteins were not significantly reduced in the immune mice. The results indicate that the antigen-specific polyclonal IgG against the M1 protein primarily targets epitopes outside the other plasma protein binding interfaces. In conclusion, this study demonstrates that AP-MS is a promising strategy to determine the relationship between antigen-specific antibodies and host-pathogen interaction networks that could be used to define subdominant protein regions of relevance for vaccine development.
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Affiliation(s)
- Eva Torres-Sangiao
- Faculty of Medicine, Division of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden; Escherichia coli Group, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain; Clinical Microbiology Lab, University Hospital Complex of Santiago de Compostela, Santiago de Compostela, Spain.
| | - Lotta Happonen
- Faculty of Medicine, Division of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Morizt Heusel
- Faculty of Medicine, Division of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden; Evosep ApS, Odense, Denmark
| | - Frida Palm
- Faculty of Medicine, Division of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Carlos Gueto-Tettay
- Faculty of Medicine, Division of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Lars Malmström
- Faculty of Medicine, Division of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Onna Shannon
- Faculty of Medicine, Division of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden; Faculty of Odontology, Section for Oral Biology and Pathology, Malmö University, Malmö, Sweden
| | - Johan Malmström
- Faculty of Medicine, Division of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden.
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Proctor EJ, Frost HR, Satapathy S, Botquin G, Urbaniec J, Gorman J, De Oliveira DMP, McArthur J, Davies MR, Botteaux A, Smeesters P, Sanderson-Smith M. Molecular characterization of the interaction between human IgG and the M-related proteins from Streptococcus pyogenes. J Biol Chem 2024; 300:105623. [PMID: 38176650 PMCID: PMC10844976 DOI: 10.1016/j.jbc.2023.105623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 12/04/2023] [Accepted: 12/20/2023] [Indexed: 01/06/2024] Open
Abstract
Group A Streptococcal M-related proteins (Mrps) are dimeric α-helical-coiled-coil cell membrane-bound surface proteins. During infection, Mrp recruit the fragment crystallizable region of human immunoglobulin G via their A-repeat regions to the bacterial surface, conferring upon the bacteria enhanced phagocytosis resistance and augmented growth in human blood. However, Mrps show a high degree of sequence diversity, and it is currently not known whether this diversity affects the Mrp-IgG interaction. Herein, we report that diverse Mrps all bind human IgG subclasses with nanomolar affinity, with differences in affinity which ranged from 3.7 to 11.1 nM for mixed IgG. Using surface plasmon resonance, we confirmed Mrps display preferential IgG-subclass binding. All Mrps were found to have a significantly weaker affinity for IgG3 (p < 0.05) compared to all other IgG subclasses. Furthermore, plasma pulldown assays analyzed via Western blotting revealed that all Mrp were able to bind IgG in the presence of other serum proteins at both 25 °C and 37 °C. Finally, we report that dimeric Mrps bind to IgG with a 1:1 stoichiometry, enhancing our understanding of this important host-pathogen interaction.
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Affiliation(s)
- Emma-Jayne Proctor
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, Australia
| | - Hannah R Frost
- Molecular Bacteriology Laboratory, European Plotkins Institute for Vaccinology (EPIV), Université Libre de Bruxelles, Brussels, Belgium
| | - Sandeep Satapathy
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, Australia; The Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Gwenaëlle Botquin
- Molecular Bacteriology Laboratory, European Plotkins Institute for Vaccinology (EPIV), Université Libre de Bruxelles, Brussels, Belgium
| | - Joanna Urbaniec
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, Australia
| | - Jody Gorman
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, Australia
| | - David M P De Oliveira
- The University of Queensland, School of Chemistry and Molecular Biosciences, Australian Infectious Diseases Research Centre, QLD, Australia
| | - Jason McArthur
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, Australia
| | - Mark R Davies
- Department of Microbiology and Immunology, at the Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Victoria, Australia
| | - Anne Botteaux
- Molecular Bacteriology Laboratory, European Plotkins Institute for Vaccinology (EPIV), Université Libre de Bruxelles, Brussels, Belgium
| | - Pierre Smeesters
- Molecular Bacteriology Laboratory, European Plotkins Institute for Vaccinology (EPIV), Université Libre de Bruxelles, Brussels, Belgium
| | - Martina Sanderson-Smith
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, Australia.
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Frick IM, Happonen L, Wrighton S, Nordenfelt P, Björck L. IdeS, a secreted proteinase of Streptococcus pyogenes, is bound to a nuclease at the bacterial surface where it inactivates opsonizing IgG antibodies. J Biol Chem 2023; 299:105345. [PMID: 37838172 PMCID: PMC10654033 DOI: 10.1016/j.jbc.2023.105345] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 09/25/2023] [Accepted: 10/04/2023] [Indexed: 10/16/2023] Open
Abstract
The important bacterial pathogen Streptococcus pyogenes secretes IdeS (immunoglobulin G-degrading enzyme of S. pyogenes), a proteinase that cleaves human immunoglobulin G (IgG) antibodies in the hinge region resulting in Fc (fragment crystallizable) and F(ab')2 (fragment antigen-binding) fragments and protects the bacteria against phagocytic killing. Experiments with radiolabeled IdeS and flow cytometry demonstrated that IdeS binds to the surface of S. pyogenes, and the interaction was most prominent in conditions resembling those in the pharynx (acidic pH and low salt), the habitat for S. pyogenes. SpnA (S. pyogenes nuclease A) is a cell wall-anchored DNase. A dose-dependent interaction between purified SpnA and IdeS was demonstrated in slot binding and surface plasmon resonance spectroscopy experiments. Gel filtration showed that IdeS forms proteolytically active complexes with SpnA in solution, and super-resolution fluorescence microscopy revealed the presence of SpnA-IdeS complexes at the surface of S. pyogenes. Finally, specific IgG antibodies binding to S. pyogenes surface antigens were efficiently cleaved by surface-associated IdeS. IdeS is secreted by all S. pyogenes isolates and cleaves IgG antibodies with a unique degree of specificity and efficiency. These properties and the finding here that the proteinase is present and fully active at the bacterial surface in complex with SpnA implicate an important role for IdeS in S. pyogenes biology and pathogenesis.
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Affiliation(s)
- Inga-Maria Frick
- Division of Infection Medicine, Department of Clinical Science, Lund University, Lund, Sweden.
| | - Lotta Happonen
- Division of Infection Medicine, Department of Clinical Science, Lund University, Lund, Sweden
| | - Sebastian Wrighton
- Division of Infection Medicine, Department of Clinical Science, Lund University, Lund, Sweden
| | - Pontus Nordenfelt
- Division of Infection Medicine, Department of Clinical Science, Lund University, Lund, Sweden
| | - Lars Björck
- Division of Infection Medicine, Department of Clinical Science, Lund University, Lund, Sweden.
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4
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Emami S, Rojas Converso T, Persson JJ, Johansson-Lindbom B. Insertion of an immunodominant T helper cell epitope within the Group A Streptococcus M protein promotes an IFN-γ-dependent shift from a non-protective to a protective immune response. Front Immunol 2023; 14:1241485. [PMID: 37654501 PMCID: PMC10465795 DOI: 10.3389/fimmu.2023.1241485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 07/28/2023] [Indexed: 09/02/2023] Open
Abstract
The common pathogen Group A Streptococcus (GAS, Streptococcus pyogenes) is an extracellular bacterium that is associated with a multitude of infectious syndromes spanning a wide range of severity. The surface-exposed M protein is a major GAS virulence factor that is also target for protective antibody responses. In this study, we use a murine immunization model to investigate aspects of the cellular and molecular foundation for protective adaptive immune responses generated against GAS. We show that a wild type M1 GAS strain induces a non-protective antibody response, while an isogenic strain carrying the immunodominant 2W T helper cell epitope within the M protein elicits an immune response that is protective against the parental non-recombinant M1 GAS strain. Although the two strains induce total anti-GAS IgG levels of similar magnitude, only the 2W-carrying strain promotes elevated titers of the complement-fixing IgG2c subclass. Protection is dependent on IFN-γ, and IFN-γ-deficient mice show a specific reduction in IgG2c levels. Our findings suggest that inclusion of the 2W T cell epitope in the M protein confers essential qualitative alterations in the adaptive immune response against GAS, and that sparsity in IFN-γ-promoting Th cell epitopes in the M protein may constitute an immune evasion mechanism, evolved to allow the pathogen to avoid attack by complement-fixing antibodies.
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Pan F, Zhu M, Liang Y, Yuan C, Zhang Y, Wang Y, Fan H, Waldor MK, Ma Z. Membrane vesicle delivery of a streptococcal M protein disrupts the blood-brain barrier by inducing autophagic endothelial cell death. Proc Natl Acad Sci U S A 2023; 120:e2219435120. [PMID: 37276410 PMCID: PMC10268326 DOI: 10.1073/pnas.2219435120] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 05/08/2023] [Indexed: 06/07/2023] Open
Abstract
M family proteins are critical virulence determinants of Streptococci. Streptococcus equi subsp. zooepidemicus (SEZ) are Group C streptococci that cause meningitis in animals and humans. SzM, the M protein of SEZ, has been linked to SEZ brain invasion. Here, we demonstrate that SzM is important in SEZ disruption of the blood-brain barrier (BBB). SEZ release SzM-bound membrane vesicles (MVs), and endocytosis of these vesicles by human brain endothelial microvascular cells (hBMECs) results in SzM-dependent cytotoxicity. Furthermore, administration of SzM-bound MVs disrupted the murine BBB. A CRISPR screen revealed that SzM cytotoxicity in hBMECs depends on PTEN-related activation of autophagic cell death. Pharmacologic inhibition of PTEN activity prevented SEZ disruption of the murine BBB and delayed mortality. Our data show that MV delivery of SzM to host cells plays a key role in SEZ pathogenicity and suggests that MV delivery of streptococcal M family proteins is likely a common streptococcal virulence mechanism.
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Affiliation(s)
- Fei Pan
- Ministry of Agriculture Key Laboratory of Animal Bacteriology, the International Joint Laboratory of Animal Health and Food Safety, and College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu210095, China
| | - Mingli Zhu
- Ministry of Agriculture Key Laboratory of Animal Bacteriology, the International Joint Laboratory of Animal Health and Food Safety, and College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu210095, China
| | - Ying Liang
- Ministry of Agriculture Key Laboratory of Animal Bacteriology, the International Joint Laboratory of Animal Health and Food Safety, and College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu210095, China
| | - Chen Yuan
- Ministry of Agriculture Key Laboratory of Animal Bacteriology, the International Joint Laboratory of Animal Health and Food Safety, and College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu210095, China
| | - Yu Zhang
- Ministry of Agriculture Key Laboratory of Animal Bacteriology, the International Joint Laboratory of Animal Health and Food Safety, and College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu210095, China
| | - Yuchang Wang
- Ministry of Agriculture Key Laboratory of Animal Bacteriology, the International Joint Laboratory of Animal Health and Food Safety, and College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu210095, China
| | - Hongjie Fan
- Ministry of Agriculture Key Laboratory of Animal Bacteriology, the International Joint Laboratory of Animal Health and Food Safety, and College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu210095, China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou225009, China
| | - Matthew K. Waldor
- HHMI, Boston, MA02115
- Brigham and Women’s HospitalDivision of Infectious Diseases, Boston, MA02115
- Department of Microbiology, Harvard Medical School, Boston, MA02115
| | - Zhe Ma
- Ministry of Agriculture Key Laboratory of Animal Bacteriology, the International Joint Laboratory of Animal Health and Food Safety, and College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu210095, China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou225009, China
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de Neergaard T, Bläckberg A, Ivarsson H, Thomasson S, Kumra Ahnlide V, Chowdhury S, Khakzad H, Bahnan W, Malmström J, Rasmussen M, Nordenfelt P. Invasive Streptococcal Infection Can Lead to the Generation of Cross-Strain Opsonic Antibodies. Microbiol Spectr 2022; 10:e0248622. [PMID: 36314947 PMCID: PMC9769875 DOI: 10.1128/spectrum.02486-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 10/07/2022] [Indexed: 12/24/2022] Open
Abstract
The human pathogen Streptococcus pyogenes causes substantial morbidity and mortality. It is unclear if antibodies developed after infections with this pathogen are opsonic and if they are strain specific or more broadly protective. Here, we quantified the opsonic-antibody response following invasive S. pyogenes infection. Four patients with S. pyogenes bacteremia between 2018 and 2020 at Skåne University Hospital in Lund, Sweden, were prospectively enrolled. Acute- and convalescent-phase sera were obtained, and the S. pyogenes isolates were genome sequenced (emm118, emm85, and two emm1 isolates). Quantitative antibody binding and phagocytosis assays were used to evaluate isolate-dependent opsonic antibody function in response to infection. Antibody binding increased modestly against the infecting isolate and across emm types in convalescent- compared to acute-phase sera for all patients. For two patients, phagocytosis increased in convalescent-phase serum both for the infecting isolate and across types. The increase was only across types for one patient, and one had no improvement. No correlation to the clinical outcomes was observed. Invasive S. pyogenes infections result in a modestly increased antibody binding with differential opsonic capacity, both nonfunctional binding and broadly opsonic binding across types. These findings question the dogma that an invasive infection should lead to a strong type-specific antibody increase rather than a more modest but broadly reactive response, as seen in these patients. Furthermore, our results indicate that an increase in antibody titers might not be indicative of an opsonic response and highlight the importance of evaluating antibody function in S. pyogenes infections. IMPORTANCE The bacterium Streptococcus pyogenes is a common cause of both mild and severe human diseases resulting in substantial morbidity and mortality each year. No vaccines are available, and our understanding of the antibody response to this human pathogen is still incomplete. Here, we carefully analyzed the opsonic antibody response following invasive infection in four patients. Unexpectedly, the patients did not always generate opsonic antibodies against the specific infecting strain. Instead, we found that some patients could generate cross-opsonic antibodies, leading to phagocytosis of bacteria across strains. The emergence of cross-opsonic antibodies is likely important for long-term immunity against S. pyogenes. Our findings question the dogma that mostly strain-specific immunity is developed after infection and add to our overall understanding of how immunity to S. pyogenes can evolve.
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Affiliation(s)
- Therese de Neergaard
- Division of Infection Medicine, Department of Clinical Sciences Lund, Faculty of Medicine, Lund University, Lund, Sweden
| | - Anna Bläckberg
- Division of Infection Medicine, Department of Clinical Sciences Lund, Faculty of Medicine, Lund University, Lund, Sweden
- Skåne University Hospital, Department of Infectious Diseases, Lund, Sweden
| | - Hanna Ivarsson
- Division of Infection Medicine, Department of Clinical Sciences Lund, Faculty of Medicine, Lund University, Lund, Sweden
| | - Sofia Thomasson
- Division of Infection Medicine, Department of Clinical Sciences Lund, Faculty of Medicine, Lund University, Lund, Sweden
| | - Vibha Kumra Ahnlide
- Division of Infection Medicine, Department of Clinical Sciences Lund, Faculty of Medicine, Lund University, Lund, Sweden
| | - Sounak Chowdhury
- Division of Infection Medicine, Department of Clinical Sciences Lund, Faculty of Medicine, Lund University, Lund, Sweden
| | - Hamed Khakzad
- Laboratory of Protein Design and Immunoengineering, STI, EPFL, Lausanne, Switzerland
| | - Wael Bahnan
- Division of Infection Medicine, Department of Clinical Sciences Lund, Faculty of Medicine, Lund University, Lund, Sweden
| | - Johan Malmström
- Division of Infection Medicine, Department of Clinical Sciences Lund, Faculty of Medicine, Lund University, Lund, Sweden
| | - Magnus Rasmussen
- Division of Infection Medicine, Department of Clinical Sciences Lund, Faculty of Medicine, Lund University, Lund, Sweden
- Skåne University Hospital, Department of Infectious Diseases, Lund, Sweden
| | - Pontus Nordenfelt
- Division of Infection Medicine, Department of Clinical Sciences Lund, Faculty of Medicine, Lund University, Lund, Sweden
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Pernow G, Shannon O, Öberg J, Nilson B, Rasmussen M. Platelet Activation and Aggregation Induced by Streptococcus bovis /Streptococcus equinus Complex. Microbiol Spectr 2022; 10:e0186122. [PMID: 36374116 PMCID: PMC9769897 DOI: 10.1128/spectrum.01861-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 10/10/2022] [Indexed: 11/16/2022] Open
Abstract
Streptococcus bovis/Streptococcus equinus complex (SBSEC) is a common cause of infective endocarditis (IE). For IE-pathogens, the capacity to activate and aggregate platelets is believed to be an important virulence mechanism. While the interactions between bacteria and platelets have been described in detail for many Gram-positive pathogens, little research has been carried out with SBSEC in this respect. Twenty-six isolates of the four most common species and subspecies of SBSEC identified in bacteremia were collected, and interactions with platelets were investigated in platelet rich plasma (PRP) from three donors. Aggregation was studied using light-transmission aggregometry and platelet activation using flow cytometry detecting surface upregulation of CD62P. Platelets and serum were treated with different inhibitors to determine mechanisms involved in platelet aggregation and activation. Twenty-two of 26 isolates induced aggregation in at least one donor, and four isolates induced aggregation in all three donors. In PRP from donor 1, isolate SL1 induced a rapid aggregation with a median time of 70 s to reach 50% aggregation. Blockade of the platelet Fc-receptor or enzymatic cleavage of IgG abolished platelet activation and aggregation. The capacity for bacteria-induced platelet aggregation was also shown to be transferable between donors through serum. SBSEC mediates platelet aggregation in an IgG and IgG-Fc-receptor dependent manner. Bacterial activation of platelets through this pathway is common for many bacteria causing IE and could be a potential therapeutic target for the prevention and treatment of this infection. IMPORTANCE The capacity of bacteria to activate and aggregate platelets is believed to contribute to the pathogenesis of IE. The Streptococcus bovis/Streptococcus equinus complex (SBSEC) contains known IE-pathogens, but there is limited research on the different subspecies ability to interact with platelets and what signaling pathways are involved. This study reports that 22 of 26 tested isolates of different subspecies within SBSEC can induce aggregation, and that aggregation is host dependent. The Fc-IgG-receptor pathway was shown essential for platelet activation and aggregation. To the best of our knowledge, this is the first study that reports on platelet interactions of SBSEC-isolates other than Streptococcus gallolyticus subspecies gallolyticus as well as the first study to report of mechanisms of platelet interaction of SBSEC-isolates. It adds SBSEC to a group of bacteria that activate and aggregate platelets via the platelet Fc-receptor. This could be a potential therapeutic target for prevention of IE.
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Affiliation(s)
- Gustav Pernow
- Division of Infection Medicine, Department of Clinical Sciences Lund, Lund University, Helsingborg Hospital, Lund, Sweden
| | - Oonagh Shannon
- Division of Infection Medicine, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
| | - Jonas Öberg
- Division of Infection Medicine, Department of Clinical Sciences Lund, Lund University, Helsingborg Hospital, Lund, Sweden
| | - Bo Nilson
- Department of Clinical Microbiology, Infection Control and Prevention, Office for Medical Services, Region Skåne, Lund, Sweden
- Division of Medical Microbiology, Department of Laboratory Medicine Lund, Medical Faculty, Lund University, Office for Medical Services, Region Skåne, Lund, Sweden
| | - Magnus Rasmussen
- Division of Infection Medicine, Department of Clinical Sciences Lund, Lund University, Skåne University Hospital, Lund, Sweden
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Bahnan W, Happonen L, Khakzad H, Kumra Ahnlide V, de Neergaard T, Wrighton S, André O, Bratanis E, Tang D, Hellmark T, Björck L, Shannon O, Malmström L, Malmström J, Nordenfelt P. A human monoclonal antibody bivalently binding two different epitopes in streptococcal M protein mediates immune function. EMBO Mol Med 2022; 15:e16208. [PMID: 36507602 PMCID: PMC9906385 DOI: 10.15252/emmm.202216208] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 11/14/2022] [Accepted: 11/16/2022] [Indexed: 12/14/2022] Open
Abstract
Group A streptococci have evolved multiple strategies to evade human antibodies, making it challenging to create effective vaccines or antibody treatments. Here, we have generated antibodies derived from the memory B cells of an individual who had successfully cleared a group A streptococcal infection. The antibodies bind with high affinity in the central region of the surface-bound M protein. Such antibodies are typically non-opsonic. However, one antibody could effectively promote vital immune functions, including phagocytosis and in vivo protection. Remarkably, this antibody primarily interacts through a bivalent dual-Fab cis mode, where the Fabs bind to two distinct epitopes in the M protein. The dual-Fab cis-binding phenomenon is conserved across different groups of M types. In contrast, other antibodies binding with normal single-Fab mode to the same region cannot bypass the M protein's virulent effects. A broadly binding, protective monoclonal antibody could be a candidate for anti-streptococcal therapy. Our findings highlight the concept of dual-Fab cis binding as a means to access conserved, and normally non-opsonic regions, regions for protective antibody targeting.
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Affiliation(s)
- Wael Bahnan
- Division of Infection Medicine, Department of Clinical Sciences Lund, Faculty of MedicineLund UniversityLundSweden
| | - Lotta Happonen
- Division of Infection Medicine, Department of Clinical Sciences Lund, Faculty of MedicineLund UniversityLundSweden
| | - Hamed Khakzad
- Equipe Signalisation Calcique et Infections MicrobiennesÉcole Normale Supérieure Paris‐SaclayGif‐sur‐YvetteFrance,Institut National de la Santé et de la Recherche Médicale (INSERM) U1282Gif‐sur‐YvetteFrance,Present address:
Université de Lorraine, Inria, LORIANancyFrance
| | - Vibha Kumra Ahnlide
- Division of Infection Medicine, Department of Clinical Sciences Lund, Faculty of MedicineLund UniversityLundSweden
| | - Therese de Neergaard
- Division of Infection Medicine, Department of Clinical Sciences Lund, Faculty of MedicineLund UniversityLundSweden
| | - Sebastian Wrighton
- Division of Infection Medicine, Department of Clinical Sciences Lund, Faculty of MedicineLund UniversityLundSweden
| | - Oscar André
- Division of Infection Medicine, Department of Clinical Sciences Lund, Faculty of MedicineLund UniversityLundSweden
| | - Eleni Bratanis
- Division of Infection Medicine, Department of Clinical Sciences Lund, Faculty of MedicineLund UniversityLundSweden
| | - Di Tang
- Division of Infection Medicine, Department of Clinical Sciences Lund, Faculty of MedicineLund UniversityLundSweden
| | - Thomas Hellmark
- Department of Clinical Sciences Lund, Division of NephrologyLund UniversityLundSweden
| | - Lars Björck
- Division of Infection Medicine, Department of Clinical Sciences Lund, Faculty of MedicineLund UniversityLundSweden
| | - Oonagh Shannon
- Division of Infection Medicine, Department of Clinical Sciences Lund, Faculty of MedicineLund UniversityLundSweden
| | - Lars Malmström
- Division of Infection Medicine, Department of Clinical Sciences Lund, Faculty of MedicineLund UniversityLundSweden
| | - Johan Malmström
- Division of Infection Medicine, Department of Clinical Sciences Lund, Faculty of MedicineLund UniversityLundSweden
| | - Pontus Nordenfelt
- Division of Infection Medicine, Department of Clinical Sciences Lund, Faculty of MedicineLund UniversityLundSweden
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9
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Kumra Ahnlide V, Kumra Ahnlide J, Wrighton S, Beech JP, Nordenfelt P. Nanoscale binding site localization by molecular distance estimation on native cell surfaces using topological image averaging. eLife 2022; 11:64709. [PMID: 35200140 PMCID: PMC8871386 DOI: 10.7554/elife.64709] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 01/13/2022] [Indexed: 01/26/2023] Open
Abstract
Antibody binding to cell surface proteins plays a crucial role in immunity, and the location of an epitope can altogether determine the immunological outcome of a host-target interaction. Techniques available today for epitope identification are costly, time-consuming, and unsuited for high-throughput analysis. Fast and efficient screening of epitope location can be useful for the development of therapeutic monoclonal antibodies and vaccines. Cellular morphology typically varies, and antibodies often bind heterogeneously across a cell surface, making traditional particle-averaging strategies challenging for accurate native antibody localization. In the present work, we have developed a method, SiteLoc, for imaging-based molecular localization on cellular surface proteins. Nanometer-scale resolution is achieved through localization in one dimension, namely, the distance from a bound ligand to a reference surface. This is done by using topological image averaging. Our results show that this method is well suited for antibody binding site measurements on native cell surface morphology and that it can be applied to other molecular distance estimations as well. Antibodies play a key role in the immune system. These proteins stick to harmful substances, such as bacteria and other disease-causing pathogens, marking them for destruction or blocking their attack. Antibodies are highly selective, and this ability has been used to target particular molecules in research, diagnostics and therapies. Typically, antibodies need to stick to a particular segment, or ‘epitope’, on the surface of a cell in order to trigger an immune response. Knowing where these regions are can help explain how these immune proteins work and aid the development of more effective drugs and diagnostic tools. One way to identify these sites is to measure the nano-distance between antibodies and other features on the cell surface. To do this, researchers take multiple images of the cell the antibody is attached to using light microscopy. Various statistical methods are then applied to create an ‘average image’ that has a higher resolution and can therefore be used to measure the distance between these two points more accurately. While this approach works on fixed shapes, like a perfect circle, it cannot handle human cells and bacteria which are less uniform and have more complex surfaces. Here, Kumra Ahnlide et al. have developed a new method called SiteLoc which can overcome this barrier. The method involves two fluorescent probes: one attached to a specific site on the cell’s surface, and the other to the antibody or another molecule of interest. These two probes emit different colours when imaged with a fluorescent microscope. To cope with objects that have uneven surfaces, such as cells and bacteria, the two signals are transformed to ‘follow’ the same geometrical shape. The relative distance between them is then measured using statistical methods. Using this approach, Kumra Ahnlide et al. were able to identify epitopes on a bacterium, and measure distances on the surface of human red blood cells. The SiteLoc system could make it easier to develop antibody-based treatments and diagnostic tools. Furthermore, it could also be beneficial to the wider research community who could use it to probe other questions that require measuring nanoscale distances.
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Affiliation(s)
- Vibha Kumra Ahnlide
- Division of Infection Medicine, Department of Clinical Sciences, Faculty of Medicine, Lund University, Lund, Sweden
| | - Johannes Kumra Ahnlide
- Division of Infection Medicine, Department of Clinical Sciences, Faculty of Medicine, Lund University, Lund, Sweden
| | - Sebastian Wrighton
- Division of Infection Medicine, Department of Clinical Sciences, Faculty of Medicine, Lund University, Lund, Sweden
| | - Jason P Beech
- Division of Solid State Physics, Department of Physics, Lund University, Lund, Sweden
| | - Pontus Nordenfelt
- Division of Infection Medicine, Department of Clinical Sciences, Faculty of Medicine, Lund University, Lund, Sweden
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10
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Distinct serotypes of streptococcal M proteins mediate fibrinogen-dependent platelet activation and pro-inflammatory effects. Infect Immun 2021; 90:e0046221. [PMID: 34898252 PMCID: PMC8852700 DOI: 10.1128/iai.00462-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Sepsis is a life-threatening complication of infection that is characterized by a dysregulated inflammatory state and disturbed hemostasis. Platelets are the main regulators of hemostasis, and they also respond to inflammation. The human pathogen Streptococcus pyogenes can cause local infection that may progress to sepsis. There are more than 200 serotypes of S. pyogenes defined according to sequence variations in the M protein. The M1 serotype is among 10 serotypes that are predominant in invasive infection. M1 protein can be released from the surface and has previously been shown to generate platelet, neutrophil, and monocyte activation. The platelet-dependent proinflammatory effects of other serotypes of M protein associated with invasive infection (M3, M5, M28, M49, and M89) are now investigated using a combination of multiparameter flow cytometry, enzyme-linked immunosorbent assay (ELISA), aggregometry, and quantitative mass spectrometry. We demonstrate that only M1, M3, and M5 protein serotypes can bind fibrinogen in plasma and mediate fibrinogen- and IgG-dependent platelet activation and aggregation, release of granule proteins, upregulation of CD62P to the platelet surface, and complex formation with neutrophils and monocytes. Neutrophil and monocyte activation, determined as upregulation of surface CD11b, is also mediated by M1, M3, and M5 protein serotypes, while M28, M49, and M89 proteins failed to mediate activation of platelets or leukocytes. Collectively, our findings reveal novel aspects of the immunomodulatory role of fibrinogen acquisition and platelet activation during streptococcal infections.
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11
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Abstract
Streptococcus pyogenes is known to cause both mucosal and systemic infections in humans. In this study, we used a combination of quantitative and structural mass spectrometry techniques to determine the composition and structure of the interaction network formed between human plasma proteins and the surfaces of different S. pyogenes serotypes. Quantitative network analysis revealed that S. pyogenes forms serotype-specific interaction networks that are highly dependent on the domain arrangement of the surface-attached M protein. Subsequent structural mass spectrometry analysis and computational modeling of one of the M proteins, M28, revealed that the network structure changes across different host microenvironments. We report that M28 binds secretory IgA via two separate binding sites with high affinity in saliva. During vascular leakage mimicked by increasing plasma concentrations in saliva, the binding of secretory IgA was replaced by the binding of monomeric IgA and C4b-binding protein (C4BP). This indicates that an upsurge of C4BP in the local microenvironment due to damage to the mucosal membrane drives the binding of C4BP and monomeric IgA to M28. These results suggest that S. pyogenes has evolved to form microenvironment-dependent host-pathogen protein complexes to combat human immune surveillance during both mucosal and systemic infections. IMPORTANCEStreptococcus pyogenes (group A Streptococcus [GAS]), is a human-specific Gram-positive bacterium. Each year, the bacterium affects 700 million people globally, leading to 160,000 deaths. The clinical manifestations of S. pyogenes are diverse, ranging from mild and common infections like tonsillitis and impetigo to life-threatening systemic conditions such as sepsis and necrotizing fasciitis. S. pyogenes expresses multiple virulence factors on its surface to localize and initiate infections in humans. Among all these expressed virulence factors, the M protein is the most important antigen. In this study, we perform an in-depth characterization of the human protein interactions formed around one of the foremost human pathogens. This strategy allowed us to decipher the protein interaction networks around different S. pyogenes strains on a global scale and to compare and visualize how such interactions are mediated by M proteins.
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12
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Yamawaki T, Nakakido M, Ujiie K, Aikawa C, Nakagawa I, Tsumoto K. Characterization of a putative maltodextrin-binding protein of Streptococcus pyogenes, SPs0871 and the development of a VHH inhibitor. Biochem Biophys Res Commun 2021; 565:1-7. [PMID: 34077827 DOI: 10.1016/j.bbrc.2021.05.056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 05/17/2021] [Indexed: 11/30/2022]
Abstract
Streptococcus pyogenes causes a wide range of human infections. Currently, antibiotics are the main treatment for S. pyogenes infection, but serious anti-microbial resistance requires alternative treatment options. To develop a novel strategy for treatment, we physicochemically characterized SPs0871, a putative maltose/maltodextrin-binding protein that is thought to have important roles in the pathogenesis of invasive streptococci. We obtained a variable domain of heavy chain of heavy-chain antibody, the smallest unit of an antibody, which specifically binds to SPs0871. Although the VHH completely inhibited the binding of maltodextrins to SPs0871, the inhibition did not lead to growth suppression of the bacteria. Our results provide important insights for development of VHH as an anti-streptococcal therapeutic.
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Affiliation(s)
- Tsukushi Yamawaki
- Department of Chemistry & Biotechnology, School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Makoto Nakakido
- Department of Chemistry & Biotechnology, School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo, 113-8656, Japan; Department of Bioengineering, School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo, 113-8656, Japan.
| | - Kan Ujiie
- Department of Bioengineering, School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Chihiro Aikawa
- Department of Microbiology, Graduate School of Medicine, Kyoto University, Kyoto, 606-8501, Japan
| | - Ichiro Nakagawa
- Department of Microbiology, Graduate School of Medicine, Kyoto University, Kyoto, 606-8501, Japan
| | - Kouhei Tsumoto
- Department of Chemistry & Biotechnology, School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo, 113-8656, Japan; Department of Bioengineering, School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo, 113-8656, Japan; Medical Proteomics Laboratory, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, 108-8639, Japan.
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13
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Jagau H, Packirisamy S, Brandon K, Herwald H. Plasma Protein Layer Concealment Protects Streptococcus pyogenes From Innate Immune Attack. Front Cell Infect Microbiol 2021; 11:633394. [PMID: 34094995 PMCID: PMC8173628 DOI: 10.3389/fcimb.2021.633394] [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: 11/25/2020] [Accepted: 05/04/2021] [Indexed: 11/13/2022] Open
Abstract
Early recognition and elimination of invading pathogens by the innate immune system, is one of the most efficient host defense mechanisms preventing the induction of systemic complications from infection. To this end the host can mobilize endogenous antimicrobials capable of killing the intruder by perforating the microbial cell wall. Here, we show that Streptococcus pyogenes can shield its outer surface with a layer of plasma proteins. This mechanism protects the bacteria from an otherwise lytic attack by LL-37 and extracellular histones, allowing the bacteria to adjust their gene regulation to an otherwise hostile environment.
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Affiliation(s)
- Hilger Jagau
- Division of Infection Medicine, Department of Clinical Sciences, Lund, Lund University, Lund, Sweden
| | - Swathi Packirisamy
- Division of Infection Medicine, Department of Clinical Sciences, Lund, Lund University, Lund, Sweden
| | - Kyle Brandon
- Division of Infection Medicine, Department of Clinical Sciences, Lund, Lund University, Lund, Sweden.,UCD School of Medicine, University College Dublin, Dublin, Ireland
| | - Heiko Herwald
- Division of Infection Medicine, Department of Clinical Sciences, Lund, Lund University, Lund, Sweden
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14
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Neumann A, Happonen L, Karlsson C, Bahnan W, Frick IM, Björck L. Streptococcal protein SIC activates monocytes and induces inflammation. iScience 2021; 24:102339. [PMID: 33855284 PMCID: PMC8027542 DOI: 10.1016/j.isci.2021.102339] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 02/21/2021] [Accepted: 03/16/2021] [Indexed: 02/08/2023] Open
Abstract
Streptococcus pyogenes is a major bacterial pathogen in the human population and isolates of the clinically important M1 serotype secrete protein Streptococcal inhibitor of complement (SIC) known to interfere with human innate immunity. Here we find that SIC from M1 bacteria interacts with TLR2 and CD14 on monocytes leading to the activation of the NF-κB and p38 MAPK pathways and the release of several pro-inflammatory cytokines (e.g. TNFα and INFγ). In human plasma, SIC binds clusterin and histidine-rich glycoprotein, and whole plasma, and these two purified plasma proteins enhanced the activation of monocytes by SIC. Isolates of the M55 serotype secrete an SIC homolog, but this protein did not activate monocytes. M1 isolates are common in cases of invasive S. pyogenes infections characterized by massive inflammation, and the results of this study indicate that the pro-inflammatory property of SIC contributes to the pathology of these severe clinical conditions.
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Affiliation(s)
- Ariane Neumann
- Division of Infection Medicine, Department of Clinical Sciences, BMC, Lund University, 22184, Lund, Sweden
| | - Lotta Happonen
- Division of Infection Medicine, Department of Clinical Sciences, BMC, Lund University, 22184, Lund, Sweden
| | - Christofer Karlsson
- Division of Infection Medicine, Department of Clinical Sciences, BMC, Lund University, 22184, Lund, Sweden
| | - Wael Bahnan
- Division of Infection Medicine, Department of Clinical Sciences, BMC, Lund University, 22184, Lund, Sweden
| | - Inga-Maria Frick
- Division of Infection Medicine, Department of Clinical Sciences, BMC, Lund University, 22184, Lund, Sweden
| | - Lars Björck
- Division of Infection Medicine, Department of Clinical Sciences, BMC, Lund University, 22184, Lund, Sweden
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15
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Kumra Ahnlide V, de Neergaard T, Sundwall M, Ambjörnsson T, Nordenfelt P. A Predictive Model of Antibody Binding in the Presence of IgG-Interacting Bacterial Surface Proteins. Front Immunol 2021; 12:629103. [PMID: 33828549 PMCID: PMC8019711 DOI: 10.3389/fimmu.2021.629103] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 02/19/2021] [Indexed: 11/24/2022] Open
Abstract
Many bacteria can interfere with how antibodies bind to their surfaces. This bacterial antibody targeting makes it challenging to predict the immunological function of bacteria-associated antibodies. The M and M-like proteins of group A streptococci (GAS) exhibit IgGFc-binding regions, which they use to reverse IgG binding orientation depending on the host environment. Unraveling the mechanism behind these binding characteristics may identify conditions under which bound IgG can drive an efficient immune response. Here, we have developed a biophysical model for describing these complex protein-antibody interactions. We show how the model can be used as a tool for studying the binding behavior of various IgG samples to M protein by performing in silico simulations and correlating this data with experimental measurements. Besides its use for mechanistic understanding, this model could potentially be used as a tool to aid in the development of antibody treatments. We illustrate this by simulating how IgG binding to GAS in serum is altered as specified amounts of monoclonal or pooled IgG is added. Phagocytosis experiments link this altered antibody binding to a physiological function and demonstrate that it is possible to predict the effect of an IgG treatment with our model. Our study gives a mechanistic understanding of bacterial antibody targeting and provides a tool for predicting the effect of antibody treatments in the presence of bacteria with IgG-modulating surface proteins.
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Affiliation(s)
- Vibha Kumra Ahnlide
- Division of Infection Medicine, Department of Clinical Sciences, Faculty of Medicine, Lund University, Lund, Sweden
| | - Therese de Neergaard
- Division of Infection Medicine, Department of Clinical Sciences, Faculty of Medicine, Lund University, Lund, Sweden
| | - Martin Sundwall
- Division of Infection Medicine, Department of Clinical Sciences, Faculty of Medicine, Lund University, Lund, Sweden
| | - Tobias Ambjörnsson
- Computational Biology and Biological Physics, Department of Astronomy and Theoretical Physics, Lund University, Lund, Sweden
| | - Pontus Nordenfelt
- Division of Infection Medicine, Department of Clinical Sciences, Faculty of Medicine, Lund University, Lund, Sweden
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16
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Abstract
M and M-like proteins are major virulence factors of the widespread and potentially deadly bacterial pathogen Streptococcus pyogenes. These proteins confer resistance against innate and adaptive immune responses by recruiting specific human proteins to the streptococcal surface. Nonimmune recruitment of immunoglobulins G (IgG) and A (IgA) through their fragment crystallizable (Fc) domains by M and M-like proteins was described almost 40 years ago, but its impact on virulence remains unresolved. These interactions have been suggested to be consequential under immune conditions at mucosal surfaces and in secretions but not in plasma, while other evidence suggests importance in evading phagocytic killing in nonimmune blood. Recently, an indirect effect of Fc-binding through ligand-induced stabilization of an M-like protein was shown to increase virulence. Nonimmune recruitment has also been seen to contribute to tissue damage in animal models of autoimmune diseases triggered by S. pyogenes infection. The damage was treatable by targeting Fc-binding. This and other potential therapeutic applications warrant renewed attention to Fc-binding by M and M-like proteins.
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Affiliation(s)
- Jori O. Mills
- Department of Chemistry & Biochemistry, La Jolla, California, United States of America
| | - Partho Ghosh
- Department of Chemistry & Biochemistry, La Jolla, California, United States of America
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17
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Persson ST, Ekström S, Papareddy P, Herwald H. Cold Atmospheric Plasma Disarms M1 Protein, an Important Streptococcal Virulence Factor. J Innate Immun 2019; 12:277-290. [PMID: 31563899 DOI: 10.1159/000502959] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 08/27/2019] [Indexed: 11/19/2022] Open
Abstract
Cold atmospheric plasma (CAP) has been demonstrated to be a successful antiseptic for chronic and infected wounds. Although experimental work has focused on elucidation of the curative power of CAP for wound healing, the molecular mechanisms behind this ability are less understood. To date, the direct effect of CAP on the activity of microbial virulence factors has not been investigated. In the present study, we therefore examined whether CAP can modulate the detrimental activity of M1 protein, one of the most studied Streptococcus pyogenes virulence determinant. Our results show that CAP abolishes the ability of M1 protein to trigger inflammatory host responses. Subsequent mass spectrometric analysis revealed that this effect was caused by oxidation of Met81 and Trp128 located at the sub-N-terminal region of M1 protein provoking a conformational change. Notably, our results also show that CAP has an insignificant effect on the host immune system, supporting the benefits of using CAP to combat infections. Considering the growing number of antibiotic-resistant bacteria, novel antimicrobial therapeutic approaches are urgently needed that do not bear the risk of inducing additional resistance. Our study therefore may open new research avenues for the development of novel approaches for the treatment of skin and wound infections caused by S. pyogenes.
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Affiliation(s)
- Sandra T Persson
- Division of Infection Medicine, Department of Clinical Sciences, Lund University Biomedical Center, Lund, Sweden,
| | - Simon Ekström
- Swedish National Infrastructure for Biological Mass Spectrometry (BioMS), Lund University, Lund, Sweden
| | - Praveen Papareddy
- Division of Infection Medicine, Department of Clinical Sciences, Lund University Biomedical Center, Lund, Sweden
| | - Heiko Herwald
- Division of Infection Medicine, Department of Clinical Sciences, Lund University Biomedical Center, Lund, Sweden
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18
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A quantitative Streptococcus pyogenes-human protein-protein interaction map reveals localization of opsonizing antibodies. Nat Commun 2019; 10:2727. [PMID: 31227708 PMCID: PMC6588558 DOI: 10.1038/s41467-019-10583-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 05/17/2019] [Indexed: 12/01/2022] Open
Abstract
A fundamental challenge in medical microbiology is to characterize the dynamic protein–protein interaction networks formed at the host–pathogen interface. Here, we generate a quantitative interaction map between the significant human pathogen, Streptococcus pyogenes, and proteins from human saliva and plasma obtained via complementary affinity-purification and bacterial-surface centered enrichment strategies and quantitative mass spectrometry. Perturbation of the network using immunoglobulin protease cleavage, mixtures of different concentrations of saliva and plasma, and different S. pyogenes serotypes and their isogenic mutants, reveals how changing microenvironments alter the interconnectivity of the interaction map. The importance of host immunoglobulins for the interaction with human complement proteins is demonstrated and potential protective epitopes of importance for phagocytosis of S. pyogenes cells are localized. The interaction map confirms several previously described protein–protein interactions; however, it also reveals a multitude of additional interactions, with possible implications for host–pathogen interactions involving other bacterial species. Characterizing host-pathogen protein interactions can help elucidate the molecular basis of bacterial infections. Here, the authors use an integrative proteomics approach to generate a quantitative map of protein interactions between Streptococcus pyogenes and human saliva and plasma.
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19
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Ermert D, Laabei M, Weckel A, Mörgelin M, Lundqvist M, Björck L, Ram S, Linse S, Blom AM. The Molecular Basis of Human IgG-Mediated Enhancement of C4b-Binding Protein Recruitment to Group A Streptococcus. Front Immunol 2019; 10:1230. [PMID: 31214187 PMCID: PMC6557989 DOI: 10.3389/fimmu.2019.01230] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 05/14/2019] [Indexed: 11/25/2022] Open
Abstract
Streptococcus pyogenes infects over 700 million people worldwide annually. Immune evasion strategies employed by the bacteria include binding of the complement inhibitors, C4b-binding protein (C4BP) and Factor H in a human-specific manner. We recently showed that human IgG increased C4BP binding to the bacterial surface, which promoted streptococcal immune evasion and increased mortality in mice. We sought to identify how IgG promotes C4BP binding to Protein H, a member of the M protein family. Dimerization of Protein H is pivotal for enhanced binding to human C4BP. First, we illustrated that Protein H, IgG, and C4BP formed a tripartite complex. Second, surface plasmon resonance revealed that Protein H binds IgG solely through Fc, but not Fab domains, and with high affinity (IgG-Protein H: KD = 0.4 nM; IgG-Fc-Protein H: KD ≤ 1.6 nM). Each IgG binds two Protein H molecules, while up to six molecules of Protein H bind one C4BP molecule. Third, interrupting Protein H dimerization either by raising temperature to 41°C or with a synthetic peptide prevented IgG-Protein H interactions. IgG-Fc fragments or monoclonal human IgG permitted maximal C4BP binding when used at concentrations from 0.1 to 10 mg/ml. In contrast, pooled human IgG enhanced C4BP binding at concentrations up to 1 mg/ml; decreased C4BP binding at 10 mg/ml occurred probably because of Fab-streptococcal interactions at these high IgG concentrations. Taken together, our data show how S. pyogenes exploits human IgG to evade complement and enhance its virulence. Elucidation of this mechanism could aid design of new therapeutics against S. pyogenes.
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Affiliation(s)
- David Ermert
- Division of Medical Protein Chemistry, Department of Translational Medicine, Lund University, Malmö, Sweden.,Division of Infectious Diseases and Immunology, Department of Medicine, University of Massachusetts Medical School, Worcester, MA, United States
| | - Maisem Laabei
- Division of Medical Protein Chemistry, Department of Translational Medicine, Lund University, Malmö, Sweden
| | - Antonin Weckel
- Division of Medical Protein Chemistry, Department of Translational Medicine, Lund University, Malmö, Sweden
| | | | - Martin Lundqvist
- Department of Biochemistry and Structural Biology, Center for Molecular Protein Science, Lund University, Lund, Sweden
| | - Lars Björck
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Sanjay Ram
- Division of Infectious Diseases and Immunology, Department of Medicine, University of Massachusetts Medical School, Worcester, MA, United States
| | - Sara Linse
- Department of Biochemistry and Structural Biology, Center for Molecular Protein Science, Lund University, Lund, Sweden
| | - Anna M Blom
- Division of Medical Protein Chemistry, Department of Translational Medicine, Lund University, Malmö, Sweden
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20
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Naegeli A, Bratanis E, Karlsson C, Shannon O, Kalluru R, Linder A, Malmström J, Collin M. Streptococcus pyogenes evades adaptive immunity through specific IgG glycan hydrolysis. J Exp Med 2019; 216:1615-1629. [PMID: 31092533 PMCID: PMC6605743 DOI: 10.1084/jem.20190293] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2019] [Revised: 04/15/2019] [Accepted: 04/16/2019] [Indexed: 12/19/2022] Open
Abstract
EndoS from Streptococcus pyogenes hydrolyzes the functionally important glycan on the Fc portion of IgG during infections in humans. In mice with IgG mediated immunity against the M1 protein on the bacteria, EndoS is a virulence factor. Streptococcus pyogenes (Group A streptococcus; GAS) is a human pathogen causing diseases from uncomplicated tonsillitis to life-threatening invasive infections. GAS secretes EndoS, an endoglycosidase that specifically cleaves the conserved N-glycan on IgG antibodies. In vitro, removal of this glycan impairs IgG effector functions, but its relevance to GAS infection in vivo is unclear. Using targeted mass spectrometry, we characterized the effects of EndoS on host IgG glycosylation during the course of infections in humans. Substantial IgG glycan hydrolysis occurred at the site of infection and systemically in the severe cases. We demonstrated decreased resistance to phagocytic killing of GAS lacking EndoS in vitro and decreased virulence in a mouse model of invasive infection. This is the first described example of specific bacterial IgG glycan hydrolysis during infection and thereby verifies the hypothesis that EndoS modifies antibodies in vivo. This mechanisms of immune evasion could have implications for treatment of severe GAS infections and for future efforts at vaccine development.
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Affiliation(s)
- Andreas Naegeli
- Faculty of Medicine, Department of Clinical Sciences, Division of Infection Medicine, Lund University, Lund, Sweden
| | - Eleni Bratanis
- Faculty of Medicine, Department of Clinical Sciences, Division of Infection Medicine, Lund University, Lund, Sweden
| | - Christofer Karlsson
- Faculty of Medicine, Department of Clinical Sciences, Division of Infection Medicine, Lund University, Lund, Sweden
| | - Oonagh Shannon
- Faculty of Medicine, Department of Clinical Sciences, Division of Infection Medicine, Lund University, Lund, Sweden
| | - Raja Kalluru
- Faculty of Medicine, Department of Clinical Sciences, Division of Infection Medicine, Lund University, Lund, Sweden
| | - Adam Linder
- Faculty of Medicine, Department of Clinical Sciences, Division of Infection Medicine, Lund University, Lund, Sweden
| | - Johan Malmström
- Faculty of Medicine, Department of Clinical Sciences, Division of Infection Medicine, Lund University, Lund, Sweden
| | - Mattias Collin
- Faculty of Medicine, Department of Clinical Sciences, Division of Infection Medicine, Lund University, Lund, Sweden
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21
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Khakzad H, Malmström J, Malmström L. Greedy de novo motif discovery to construct motif repositories for bacterial proteomes. BMC Bioinformatics 2019; 20:141. [PMID: 30999854 PMCID: PMC6471678 DOI: 10.1186/s12859-019-2686-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Bacterial surfaces are complex systems, constructed from membranes, peptidoglycan and, importantly, proteins. The proteins play crucial roles as critical regulators of how the bacterium interacts with and survive in its environment. A full catalog of the motifs in protein families and their relative conservation grade is a prerequisite to target the protein-protein interaction that bacterial surface protein makes to host proteins. RESULTS In this paper, we propose a greedy approach to identify conserved motifs in large sequence families iteratively. Each iteration discovers a motif de novo and masks all occurrences of that motif. Remaining unmasked sequences are subjected to the next round of motif detection until no more significant motifs can be found. We demonstrate the utility of the method through the construction of a proteome-wide motif repository for Group A Streptococcus (GAS), a significant human pathogen. GAS produce numerous surface proteins that interact with over 100 human plasma proteins, helping the bacteria to evade the host immune response. We used the repository to find that proteins part of the bacterial surface has motif architectures that differ from intracellular proteins. CONCLUSIONS We elucidate that the M protein, a coiled-coil homodimer that extends over 500 A from the cell wall, has a motif architecture that differs between various GAS strains. As the M protein is known to bind a variety of different plasma proteins, the results indicate that the different motif architectures are responsible for the quantitative differences of plasma proteins that various strains bind. The speed and applicability of the method enable its application to all major human pathogens.
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Affiliation(s)
- Hamed Khakzad
- Faculty of Science, Institute for Computational Science, University of Zurich, 429 Winterthurerstrasse, 190, Zurich, CH-8057 Switzerland
- Service and Support 430 for Science IT (S3IT), University of Zurich, Winterthurerstrasse, 190, Zurich, CH-8057 431 Switzerland
- Swiss Institute of Bioinformatics (SIB), Lausanne, Switzerland
| | - Johan Malmström
- Division of Infection Medicine, Department of Clinical 432 Sciences, Lund University, Tornavagen, 10, Lund, SE-22184 Sweden
| | - Lars Malmström
- Faculty of Science, Institute for Computational Science, University of Zurich, 429 Winterthurerstrasse, 190, Zurich, CH-8057 Switzerland
- Service and Support 430 for Science IT (S3IT), University of Zurich, Winterthurerstrasse, 190, Zurich, CH-8057 431 Switzerland
- Swiss Institute of Bioinformatics (SIB), Lausanne, Switzerland
- Division of Infection Medicine, Department of Clinical 432 Sciences, Lund University, Tornavagen, 10, Lund, SE-22184 Sweden
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22
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Abstract
In the past decade, the field of the cellular microbiology of group A Streptococcus (S. pyogenes) infection has made tremendous advances and touched upon several important aspects of pathogenesis, including receptor biology, invasive and evasive phenomena, inflammasome activation, strain-specific autophagic bacterial killing, and virulence factor-mediated programmed cell death. The noteworthy aspect of S. pyogenes-mediated cell signaling is the recognition of the role of M protein in a variety of signaling events, starting with the targeting of specific receptors on the cell surface and on through the induction and evasion of NETosis, inflammasome, and autophagy/xenophagy to pyroptosis and apoptosis. Variations in reports on S. pyogenes-mediated signaling events highlight the complex mechanism of pathogenesis and underscore the importance of the host cell and S. pyogenes strain specificity, as well as in vitro/in vivo experimental parameters. The severity of S. pyogenes infection is, therefore, dependent on the virulence gene expression repertoire in the host environment and on host-specific dynamic signaling events in response to infection. Commonly known as an extracellular pathogen, S. pyogenes finds host macrophages as safe havens wherein it survives and even multiplies. The fact that endothelial cells are inherently deficient in autophagic machinery compared to epithelial cells and macrophages underscores the invasive nature of S. pyogenes and its ability to cause severe systemic diseases. S. pyogenes is still one of the top 10 causes of infectious mortality. Understanding the orchestration of dynamic host signaling networks will provide a better understanding of the increasingly complex mechanism of S. pyogenes diseases and novel ways of therapeutically intervening to thwart severe and often fatal infections.
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23
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Hauri S, Khakzad H, Happonen L, Teleman J, Malmström J, Malmström L. Rapid determination of quaternary protein structures in complex biological samples. Nat Commun 2019; 10:192. [PMID: 30643114 PMCID: PMC6331586 DOI: 10.1038/s41467-018-07986-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 12/07/2018] [Indexed: 12/26/2022] Open
Abstract
The understanding of complex biological systems is still hampered by limited knowledge of biologically relevant quaternary protein structures. Here, we demonstrate quaternary structure determination in biological samples using a combination of chemical cross-linking, high-resolution mass spectrometry and high-accuracy protein structure modeling. This approach, termed targeted cross-linking mass spectrometry (TX-MS), relies on computational structural models to score sets of targeted cross-linked peptide signals acquired using a combination of mass spectrometry acquisition techniques. We demonstrate the utility of TX-MS by creating a high-resolution quaternary model of a 1.8 MDa protein complex composed of a pathogen surface protein and ten human plasma proteins. The model is based on a dense network of cross-link distance constraints obtained directly in a mixture of human plasma and live bacteria. These results demonstrate that TX-MS can increase the applicability of flexible backbone docking algorithms to large protein complexes by providing rich cross-link distance information from complex biological samples. Protein structure determination in complex biological samples is still challenging. Here, the authors develop a computational modeling-guided cross-linking mass spectrometry method, obtaining a high-resolution model of a 1.8 MDa protein assembly from cross-links detected in a mixture of human plasma and bacteria.
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Affiliation(s)
- Simon Hauri
- Division of Infection Medicine, Department of Clinical Sciences Lund, Faculty of Medicine, Lund University, Klinikgatan 32, SE-22184, Lund, Sweden
| | - Hamed Khakzad
- S3IT, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland.,Institute for Computational Science, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
| | - Lotta Happonen
- Division of Infection Medicine, Department of Clinical Sciences Lund, Faculty of Medicine, Lund University, Klinikgatan 32, SE-22184, Lund, Sweden
| | - Johan Teleman
- Division of Infection Medicine, Department of Clinical Sciences Lund, Faculty of Medicine, Lund University, Klinikgatan 32, SE-22184, Lund, Sweden
| | - Johan Malmström
- Division of Infection Medicine, Department of Clinical Sciences Lund, Faculty of Medicine, Lund University, Klinikgatan 32, SE-22184, Lund, Sweden.
| | - Lars Malmström
- Division of Infection Medicine, Department of Clinical Sciences Lund, Faculty of Medicine, Lund University, Klinikgatan 32, SE-22184, Lund, Sweden. .,S3IT, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland. .,Institute for Computational Science, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland.
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24
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Palm F, Sjöholm K, Malmström J, Shannon O. Complement Activation Occurs at the Surface of Platelets Activated by Streptococcal M1 Protein and This Results in Phagocytosis of Platelets. THE JOURNAL OF IMMUNOLOGY 2018; 202:503-513. [PMID: 30541884 DOI: 10.4049/jimmunol.1800897] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 11/13/2018] [Indexed: 12/12/2022]
Abstract
Platelets circulate the bloodstream and principally maintain hemostasis. Disturbed hemostasis, a dysregulated inflammatory state, and a decreased platelet count are all hallmarks of severe invasive Streptococcus pyogenes infection, sepsis. We have previously demonstrated that the released M1 protein from S. pyogenes activates platelets, and this activation is dependent on the binding of M1 protein, fibrinogen, and M1-specific IgG to platelets in susceptible donors. In this study, we characterize the M1-associated protein interactions in human plasma and investigate the acquisition of proteins to the surface of activated platelets and the consequences for platelet immune function. Using quantitative mass spectrometry, M1 protein was determined to form a protein complex in plasma with statistically significant enrichment of fibrinogen, IgG3, and complement components, especially C1q. Using flow cytometry, these plasma proteins were also confirmed to be acquired to the platelet surface, resulting in complement activation on M1-activated human platelets. Furthermore, we demonstrated an increased phagocytosis of M1-activated platelets by monocytes, which was not observed with other physiological platelet agonists. This reveals a novel mechanism of complement activation during streptococcal sepsis, which contributes to the platelet consumption that occurs in sepsis.
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Affiliation(s)
- Frida Palm
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, SE-22184 Lund, Sweden
| | - Kristoffer Sjöholm
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, SE-22184 Lund, Sweden
| | - Johan Malmström
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, SE-22184 Lund, Sweden
| | - Oonagh Shannon
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, SE-22184 Lund, Sweden
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25
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Jones S, Moreland NJ, Zancolli M, Raynes J, Loh JMS, Smeesters PR, Sriskandan S, Carapetis JR, Fraser JD, Goldblatt D. Development of an opsonophagocytic killing assay for group a streptococcus. Vaccine 2018; 36:3756-3763. [PMID: 29776751 DOI: 10.1016/j.vaccine.2018.05.056] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 04/17/2018] [Accepted: 05/11/2018] [Indexed: 10/14/2022]
Abstract
Group A Streptococcus (GAS) or Streptococcus pyogenes is responsible for an estimated 500,000 deaths worldwide each year. Protection against GAS infection is thought to be mediated by phagocytosis, enhanced by bacteria-specific antibody. There are no licenced GAS vaccines, despite many promising candidates in preclinical and early stage clinical development, the most advanced of which are based on the GAS M-protein. Vaccine progress has been hindered, in part, by the lack of a standardised functional assay suitable for vaccine evaluation. Current assays, developed over 50 years ago, rely on non-immune human whole blood as a source of neutrophils and complement. Variations in complement and neutrophil activity between donors result in variable data that is difficult to interpret. We have developed an opsonophagocytic killing assay (OPKA) for GAS that utilises dimethylformamide (DMF)-differentiated human promyelocytic leukemia cells (HL-60) as a source of neutrophils and baby rabbit complement, thus removing the major sources of variation in current assays. We have standardised the OPKA for several clinically relevant GAS strain types (emm1, emm6 and emm12) and have shown antibody-specific killing for each emm-type using M-protein specific rabbit antisera. Specificity was demonstrated by pre-incubation of the antisera with homologous M-protein antigens that blocked antibody-specific killing. Additional qualifications of the GAS OPKA, including the assessment of the accuracy, precision, linearity and the lower limit of quantification, were also performed. This GAS OPKA assay has the potential to provide a robust and reproducible platform to accelerate GAS vaccine development.
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Affiliation(s)
- Scott Jones
- Immunobiology, UCL Great Ormond Street Institute of Child Health Biomedical Research Centre, 30 Guilford Street, London WC1N 1EH, United Kingdom.
| | - Nicole J Moreland
- Department of Molecular Medicine & Pathology, School of Medical Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Marta Zancolli
- Immunobiology, UCL Great Ormond Street Institute of Child Health Biomedical Research Centre, 30 Guilford Street, London WC1N 1EH, United Kingdom
| | - Jeremy Raynes
- Department of Molecular Medicine & Pathology, School of Medical Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Jacelyn M S Loh
- Department of Molecular Medicine & Pathology, School of Medical Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Pierre R Smeesters
- Molecular Bacteriology Laboratory, Universite ́ Libre de Bruxelles and Academic Children Hospital, Brussels, Belgium; Murdoch Children's Research Institute and University of Melbourne, Melbourne, Australia
| | - Shiranee Sriskandan
- Faculty of Medicine, Imperial College London, Commonwealth Building, Hammersmith Hospital, Du Cane Road, London W12 0NN, United Kingdom
| | - Jonathan R Carapetis
- Telethon Kids Institute, University of Western Australia and Perth Children's Hospital, Perth, Australia
| | - John D Fraser
- Department of Molecular Medicine & Pathology, School of Medical Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - David Goldblatt
- Immunobiology, UCL Great Ormond Street Institute of Child Health Biomedical Research Centre, 30 Guilford Street, London WC1N 1EH, United Kingdom
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26
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Ermert D, Weckel A, Magda M, Mörgelin M, Shaughnessy J, Rice PA, Björck L, Ram S, Blom AM. Human IgG Increases Virulence of Streptococcus pyogenes through Complement Evasion. THE JOURNAL OF IMMUNOLOGY 2018; 200:3495-3505. [PMID: 29626087 DOI: 10.4049/jimmunol.1800090] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 03/12/2018] [Indexed: 12/21/2022]
Abstract
Streptococcus pyogenes is an exclusively human pathogen that can provoke mild skin and throat infections but can also cause fatal septicemia. This gram-positive bacterium has developed several strategies to evade the human immune system, enabling S. pyogenes to survive in the host. These strategies include recruiting several human plasma proteins, such as the complement inhibitor, C4b-binding protein (C4BP), and human (hu)-IgG through its Fc region to the bacterial surface to evade immune recognition. We identified a novel virulence mechanism whereby IgG-enhanced binding of C4BP to five of 12 tested S. pyogenes strains expressed diverse M proteins that are important surface-expressed virulence factors. Importantly, all strains that bound C4BP in the absence of IgG bound more C4BP when IgG was present. Further studies with an M1 strain that additionally expressed protein H, also a member of the M protein family, revealed that binding of hu-IgG Fc to protein H increased the affinity of protein H for C4BP. Increased C4BP binding accentuated complement downregulation, resulting in diminished bacterial killing. Accordingly, mortality from S. pyogenes infection in hu-C4BP transgenic mice was increased when hu-IgG or its Fc portion alone was administered concomitantly. Electron microscopy analysis of human tissue samples with necrotizing fasciitis confirmed increased C4BP binding to S. pyogenes when IgG was present. Our findings provide evidence of a paradoxical function of hu-IgG bound through Fc to diverse S. pyogenes isolates that increases their virulence and may counteract the beneficial effects of IgG opsonization.
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Affiliation(s)
- David Ermert
- Division of Medical Protein Chemistry, Department of Translational Medicine, Lund University, 214 28 Malmo, Sweden; .,Division of Infectious Diseases and Immunology, Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01605; and
| | - Antonin Weckel
- Division of Medical Protein Chemistry, Department of Translational Medicine, Lund University, 214 28 Malmo, Sweden
| | - Michal Magda
- Division of Medical Protein Chemistry, Department of Translational Medicine, Lund University, 214 28 Malmo, Sweden
| | - Matthias Mörgelin
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, 221 84 Lund, Sweden
| | - Jutamas Shaughnessy
- Division of Infectious Diseases and Immunology, Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01605; and
| | - Peter A Rice
- Division of Infectious Diseases and Immunology, Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01605; and
| | - Lars Björck
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, 221 84 Lund, Sweden
| | - Sanjay Ram
- Division of Infectious Diseases and Immunology, Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01605; and
| | - Anna M Blom
- Division of Medical Protein Chemistry, Department of Translational Medicine, Lund University, 214 28 Malmo, Sweden
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27
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Karlsson CAQ, Järnum S, Winstedt L, Kjellman C, Björck L, Linder A, Malmström JA. Streptococcus pyogenes Infection and the Human Proteome with a Special Focus on the Immunoglobulin G-cleaving Enzyme IdeS. Mol Cell Proteomics 2018; 17:1097-1111. [PMID: 29511047 PMCID: PMC5986240 DOI: 10.1074/mcp.ra117.000525] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 02/16/2018] [Indexed: 11/16/2022] Open
Abstract
Infectious diseases are characterized by a complex interplay between host and pathogen, but how these interactions impact the host proteome is unclear. Here we applied a combined mass spectrometry-based proteomics strategy to investigate how the human proteome is transiently modified by the pathogen Streptococcus pyogenes, with a particular focus on bacterial cleavage of IgG in vivo. In invasive diseases, S. pyogenes evokes a massive host response in blood, whereas superficial diseases are characterized by a local leakage of several blood plasma proteins at the site of infection including IgG. S. pyogenes produces IdeS, a protease cleaving IgG in the lower hinge region and we find highly effective IdeS-cleavage of IgG in samples from local IgG poor microenvironments. The results show that IdeS contributes to the adaptation of S. pyogenes to its normal ecological niches. Additionally, the work identifies novel clinical opportunities for in vivo pathogen detection.
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Affiliation(s)
- Christofer A Q Karlsson
- From the ‡Lund University, Division of Infection Medicine, Department of Clinical Sciences, Solvegatan 19, BMC, Lund, 221 84 Lund, Sweden
| | - Sofia Järnum
- §Hansa Medical AB, Scheelevägen 22, 223 63 Lund, Sweden
| | - Lena Winstedt
- §Hansa Medical AB, Scheelevägen 22, 223 63 Lund, Sweden
| | | | - Lars Björck
- From the ‡Lund University, Division of Infection Medicine, Department of Clinical Sciences, Solvegatan 19, BMC, Lund, 221 84 Lund, Sweden
| | - Adam Linder
- From the ‡Lund University, Division of Infection Medicine, Department of Clinical Sciences, Solvegatan 19, BMC, Lund, 221 84 Lund, Sweden
| | - Johan A Malmström
- From the ‡Lund University, Division of Infection Medicine, Department of Clinical Sciences, Solvegatan 19, BMC, Lund, 221 84 Lund, Sweden;
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28
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Raynes JM, Young PG, Proft T, Williamson DA, Baker EN, Moreland NJ. Protein adhesins as vaccine antigens for Group A Streptococcus. Pathog Dis 2018; 76:4919728. [DOI: 10.1093/femspd/fty016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 03/01/2018] [Indexed: 12/20/2022] Open
Affiliation(s)
- J M Raynes
- School of Medical Sciences, The University of Auckland, 85 Park Road, Auckland 1023, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3A Symonds Street, Auckland 1010, New Zealand
| | - P G Young
- Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3A Symonds Street, Auckland 1010, New Zealand
- School of Biological Sciences, University of Auckland, 5 Symonds Street, Auckland 1010, New Zealand
| | - T Proft
- School of Medical Sciences, The University of Auckland, 85 Park Road, Auckland 1023, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3A Symonds Street, Auckland 1010, New Zealand
| | - D A Williamson
- Microbiological Diagnostic Unit Public Health Laboratory, Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria 3000, Australia
| | - E N Baker
- Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3A Symonds Street, Auckland 1010, New Zealand
- School of Biological Sciences, University of Auckland, 5 Symonds Street, Auckland 1010, New Zealand
| | - N J Moreland
- School of Medical Sciences, The University of Auckland, 85 Park Road, Auckland 1023, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3A Symonds Street, Auckland 1010, New Zealand
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29
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Abstract
Group A Streptococcus (GAS) is a leading human bacterial pathogen with diverse clinical manifestations. Macrophages constitute a critical first line of host defense against GAS infection, using numerous surface and intracellular receptors such as Toll-like receptors and inflammasomes for pathogen recognition and activation of inflammatory signaling pathways. Depending on the intensity of the GAS infection, activation of these signaling cascades may provide a beneficial early alarm for effective immune clearance, or conversely, may cause hyperinflammation and tissue injury during severe invasive infection. Although traditionally considered an extracellular pathogen, GAS can invade and replicate within macrophages using specific molecular mechanisms to resist phagolysosomal and xenophagic killing. Unraveling GAS-macrophage encounters may reveal new treatment options for this leading agent of infection-associated mortality. [Formula: see text].
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Affiliation(s)
- J Andrés Valderrama
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Victor Nizet
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA.,Skaggs School of Pharmacy & Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093, USA
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30
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Blom AM, Magda M, Kohl L, Shaughnessy J, Lambris JD, Ram S, Ermert D. Factor H-IgG Chimeric Proteins as a Therapeutic Approach against the Gram-Positive Bacterial Pathogen Streptococcus pyogenes. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2017; 199:3828-3839. [PMID: 29084837 PMCID: PMC5698128 DOI: 10.4049/jimmunol.1700426] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 09/30/2017] [Indexed: 11/19/2022]
Abstract
Bacteria can cause life-threatening infections, such as pneumonia, meningitis, or sepsis. Antibiotic therapy is a mainstay of treatment, although antimicrobial resistance has drastically increased over the years. Unfortunately, safe and effective vaccines against most pathogens have not yet been approved, and thus developing alternative treatments is important. We analyzed the efficiency of factor H (FH)6-7/Fc, a novel antibacterial immunotherapeutic protein against the Gram-positive bacterium Streptococcus pyogenes This protein is composed of two domains of complement inhibitor human FH (FH complement control protein modules 6 and 7) that bind to S. pyogenes, linked to the Fc region of IgG (FH6-7/Fc). FH6-7/Fc has previously been shown to enhance complement-dependent killing of, and facilitate bacterial clearance in, animal models of the Gram-negative pathogens Haemophilus influenzae and Neisseria meningitidis We hypothesized that activation of complement by FH6-7/Fc on the surface of Gram-positive bacteria such as S. pyogenes will enable professional phagocytes to eliminate the pathogen. We found that FH6-7/Fc alleviated S. pyogenes-induced sepsis in a transgenic mouse model expressing human FH (S. pyogenes binds FH in a human-specific manner). Furthermore, FH6-7/Fc, which binds to protein H and selected M proteins, displaced FH from the bacterial surface, enhanced alternative pathway activation, and reduced bacterial blood burden by opsonophagocytosis in a C3-dependent manner in an ex vivo human whole-blood model. In conclusion, FH-Fc chimeric proteins could serve as adjunctive treatments against multidrug-resistant bacterial infections.
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Affiliation(s)
- Anna M Blom
- Department of Translational Medicine, Medical Protein Chemistry, Lund University, Skåne County Council, Malmö 20502, Sweden
| | - Michal Magda
- Department of Translational Medicine, Medical Protein Chemistry, Lund University, Skåne County Council, Malmö 20502, Sweden
| | - Lisa Kohl
- Department of Translational Medicine, Medical Protein Chemistry, Lund University, Skåne County Council, Malmö 20502, Sweden
| | - Jutamas Shaughnessy
- Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, MA 01605; and
| | - John D Lambris
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Sanjay Ram
- Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, MA 01605; and
| | - David Ermert
- Department of Translational Medicine, Medical Protein Chemistry, Lund University, Skåne County Council, Malmö 20502, Sweden;
- Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, MA 01605; and
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31
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Persson ST, Hauri S, Malmström J, Herwald H. Leucocyte recruitment and molecular fortification of keratinocytes triggered by streptococcal M1 protein. Cell Microbiol 2017; 20. [DOI: 10.1111/cmi.12792] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 09/07/2017] [Accepted: 09/26/2017] [Indexed: 01/02/2023]
Affiliation(s)
- Sandra T. Persson
- Division of Infection Medicine, Department of Clinical Sciences, Biomedical Center; Lund University; Lund Sweden
| | - Simon Hauri
- Division of Infection Medicine, Department of Clinical Sciences, Biomedical Center; Lund University; Lund Sweden
| | - Johan Malmström
- Division of Infection Medicine, Department of Clinical Sciences, Biomedical Center; Lund University; Lund Sweden
| | - Heiko Herwald
- Division of Infection Medicine, Department of Clinical Sciences, Biomedical Center; Lund University; Lund Sweden
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32
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Herrera AL, Suso K, Allison S, Simon A, Schlenker E, Huber VC, Chaussee MS. Binding host proteins to the M protein contributes to the mortality associated with influenza- Streptococcus pyogenes superinfections. MICROBIOLOGY-SGM 2017; 163:1445-1456. [PMID: 28942759 DOI: 10.1099/mic.0.000532] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The mortality associated with influenza A virus (IAV) is often due to the development of secondary bacterial infections known as superinfections. The group A streptococcus (GAS) is a relatively uncommon cause of IAV superinfections, but the mortality of these infections is high. We used a murine model to determine whether the surface-localized GAS M protein contributes to the outcome of IAV-GAS superinfections. A comparison between wild-type GAS and an M protein mutant strain (emm3) showed that the M3 protein was essential to virulence. To determine whether the binding, or recruitment, of host proteins to the bacterial surface contributed to virulence, GAS was suspended with BALF collected from mice that had recovered from a sub-lethal infection with IAV. Following intranasal inoculation of naïve mice, the mortality associated with the wild-type strain, but not the emm3 mutant strain, was greater compared to mice inoculated with GAS suspended with either BALF from uninfected mice or PBS. Further analyses showed that both albumin and fibrinogen (Fg) were more abundant in the respiratory tract 8 days after IAV infection, that M3 bound both proteins to the bacterial surface, and that suspension of GAS with either protein increased GAS virulence in the absence of antecedent IAV infection. Overall, the results showed that M3 is essential to the virulence of GAS in an IAV superinfection and suggested that increased abundance of albumin and Fg in the respiratory tract following IAV infection enhanced host susceptibility to secondary GAS infection.
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Affiliation(s)
- Andrea L Herrera
- Division of Basic Biomedical Sciences, The Sanford School of Medicine of the University of South Dakota, Vermillion, South Dakota, USA
| | - Kuta Suso
- Division of Basic Biomedical Sciences, The Sanford School of Medicine of the University of South Dakota, Vermillion, South Dakota, USA
| | - Stephanie Allison
- Division of Basic Biomedical Sciences, The Sanford School of Medicine of the University of South Dakota, Vermillion, South Dakota, USA
| | - Abby Simon
- Division of Basic Biomedical Sciences, The Sanford School of Medicine of the University of South Dakota, Vermillion, South Dakota, USA
| | - Evelyn Schlenker
- Division of Basic Biomedical Sciences, The Sanford School of Medicine of the University of South Dakota, Vermillion, South Dakota, USA
| | - Victor C Huber
- Division of Basic Biomedical Sciences, The Sanford School of Medicine of the University of South Dakota, Vermillion, South Dakota, USA
| | - Michael S Chaussee
- Division of Basic Biomedical Sciences, The Sanford School of Medicine of the University of South Dakota, Vermillion, South Dakota, USA
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33
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Ghosh P. Variation, Indispensability, and Masking in the M protein. Trends Microbiol 2017; 26:132-144. [PMID: 28867148 DOI: 10.1016/j.tim.2017.08.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 07/26/2017] [Accepted: 08/08/2017] [Indexed: 11/17/2022]
Abstract
The M protein is the major surface-associated virulence factor of group A Streptococcus (GAS) and an antigenically variable target of host immunity. How selection pressures to escape immune recognition, maintain indispensable functions, and mask vulnerabilities have shaped the sequences of the >220M protein types is unclear. Recent experiments have shed light on this question by showing that, hidden within the antigenic variability of many M protein types, are sequence patterns conserved for recruiting human C4b-binding protein (C4BP). Other host factors may be recruited in a similar manner by conserved but hidden sequence patterns in the M protein. The identification of such patterns may be applicable to the development of a GAS vaccine.
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Affiliation(s)
- Partho Ghosh
- Department of Chemistry & Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA.
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34
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Group A streptococcal M protein activates the NLRP3 inflammasome. Nat Microbiol 2017; 2:1425-1434. [PMID: 28784982 DOI: 10.1038/s41564-017-0005-6] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 07/04/2017] [Indexed: 12/17/2022]
Abstract
Group A Streptococcus (GAS) is among the top ten causes of infection-related mortality in humans. M protein is the most abundant GAS surface protein, and M1 serotype GAS strains are associated with invasive infections, including necrotizing fasciitis and toxic shock syndrome. Here, we report that released, soluble M1 protein triggers programmed cell death in macrophages (Mϕ). M1 served as a second signal for caspase-1-dependent NLRP3 inflammasome activation, inducing maturation and release of proinflammatory cytokine interleukin-1β (IL-1β) and macrophage pyroptosis. The structurally dynamic B-repeat domain of M1 was critical for inflammasome activation, which involved K+ efflux and M1 protein internalization by clathrin-mediated endocytosis. Mouse intraperitoneal challenge showed that soluble M1 was sufficient and specific for IL-1β activation, which may represent an early warning to activate host immunity against the pathogen. Conversely, in systemic infection, hyperinflammation associated with M1-mediated pyroptosis and IL-1β release could aggravate tissue injury.
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35
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Sjöholm K, Kilsgård O, Teleman J, Happonen L, Malmström L, Malmström J. Targeted Proteomics and Absolute Protein Quantification for the Construction of a Stoichiometric Host-Pathogen Surface Density Model. Mol Cell Proteomics 2017; 16:S29-S41. [PMID: 28183813 PMCID: PMC5393399 DOI: 10.1074/mcp.m116.063966] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 01/23/2017] [Indexed: 11/06/2022] Open
Abstract
Sepsis is a systemic immune response responsible for considerable morbidity and mortality. Molecular modeling of host-pathogen interactions in the disease state represents a promising strategy to define molecular events of importance for the transition from superficial to invasive infectious diseases. Here we used the Gram-positive bacterium Streptococcus pyogenes as a model system to establish a mass spectrometry based workflow for the construction of a stoichiometric surface density model between the S. pyogenes surface, the surface virulence factor M-protein, and adhered human blood plasma proteins. The workflow relies on stable isotope labeled reference peptides and selected reaction monitoring mass spectrometry analysis of a wild-type strain and an M-protein deficient mutant strain, to generate absolutely quantified protein stoichiometry ratios between S. pyogenes and interacting plasma proteins. The stoichiometry ratios in combination with a novel targeted mass spectrometry method to measure cell numbers enabled the construction of a stoichiometric surface density model using protein structures available from the protein data bank. The model outlines the topology and density of the host-pathogen protein interaction network on the S. pyogenes bacterial surface, revealing a dense and highly organized protein interaction network. Removal of the M-protein from S. pyogenes introduces a drastic change in the network topology, validated by electron microscopy. We propose that the stoichiometric surface density model of S. pyogenes in human blood plasma represents a scalable framework that can continuously be refined with the emergence of new results. Future integration of new results will improve the understanding of protein-protein interactions and their importance for bacterial virulence. Furthermore, we anticipate that the general properties of the developed workflow will facilitate the production of stoichiometric surface density models for other types of host-pathogen interactions.
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Affiliation(s)
- Kristoffer Sjöholm
- From the ‡Department of Immunotechnology, Faculty of Engineering, Lund University, Sweden
- §Division of Infection Medicine, Department of Clinical Sciences, Lund University, Sweden
| | - Ola Kilsgård
- §Division of Infection Medicine, Department of Clinical Sciences, Lund University, Sweden
| | - Johan Teleman
- §Division of Infection Medicine, Department of Clinical Sciences, Lund University, Sweden
| | - Lotta Happonen
- §Division of Infection Medicine, Department of Clinical Sciences, Lund University, Sweden
| | | | - Johan Malmström
- §Division of Infection Medicine, Department of Clinical Sciences, Lund University, Sweden;
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36
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Bergmann S, Eichhorn I, Kohler TP, Hammerschmidt S, Goldmann O, Rohde M, Fulde M. SCM, the M Protein of Streptococcus canis Binds Immunoglobulin G. Front Cell Infect Microbiol 2017; 7:80. [PMID: 28401063 PMCID: PMC5368172 DOI: 10.3389/fcimb.2017.00080] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Accepted: 02/28/2017] [Indexed: 11/13/2022] Open
Abstract
The M protein of Streptococcus canis (SCM) is a virulence factor and serves as a surface-associated receptor with a particular affinity for mini-plasminogen, a cleavage product of the broad-spectrum serine protease plasmin. Here, we report that SCM has an additional high-affinity immunoglobulin G (IgG) binding activity. The ability of a particular S. canis isolate to bind to IgG significantly correlates with a scm-positive phenotype, suggesting a dominant role of SCM as an IgG receptor. Subsequent heterologous expression of SCM in non-IgG binding S. gordonii and Western Blot analysis with purified recombinant SCM proteins confirmed its IgG receptor function. As expected for a zoonotic agent, the SCM-IgG interaction is species-unspecific, with a particular affinity of SCM for IgGs derived from human, cats, dogs, horses, mice, and rabbits, but not from cows and goats. Similar to other streptococcal IgG-binding proteins, the interaction between SCM and IgG occurs via the conserved Fc domain and is, therefore, non-opsonic. Interestingly, the interaction between SCM and IgG-Fc on the bacterial surface specifically prevents opsonization by C1q, which might constitute another anti-phagocytic mechanism of SCM. Extensive binding analyses with a variety of different truncated SCM fragments defined a region of 52 amino acids located in the central part of the mature SCM protein which is important for IgG binding. This binding region is highly conserved among SCM proteins derived from different S. canis isolates but differs significantly from IgG-Fc receptors of S. pyogenes and S. dysgalactiae sub. equisimilis, respectively. In summary, we present an additional role of SCM in the pathogen-host interaction of S. canis. The detailed analysis of the SCM-IgG interaction should contribute to a better understanding of the complex roles of M proteins in streptococcal pathogenesis.
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Affiliation(s)
- Simone Bergmann
- Department of Medical Microbiology, Helmholtz Center for Infection Research Braunschweig, Germany
| | - Inga Eichhorn
- Institute of Microbiology and Epizootics, Centre for Infection Medicine, Freie Universität Berlin Berlin, Germany
| | - Thomas P Kohler
- Department Genetics of Microorganisms, Interfaculty Institute for Genetics and Functional Genomics, Ernst-Moritz-Arndt Universität Greifswald Greifswald, Germany
| | - Sven Hammerschmidt
- Department Genetics of Microorganisms, Interfaculty Institute for Genetics and Functional Genomics, Ernst-Moritz-Arndt Universität Greifswald Greifswald, Germany
| | - Oliver Goldmann
- Department of Infection Immunology, Helmholtz Center for Infection Research Braunschweig, Germany
| | - Manfred Rohde
- Central Facility for Microscopy, Helmholtz Center for Infection Research Braunschweig, Germany
| | - Marcus Fulde
- Department of Medical Microbiology, Helmholtz Center for Infection ResearchBraunschweig, Germany; Institute of Microbiology and Epizootics, Centre for Infection Medicine, Freie Universität BerlinBerlin, Germany
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Säll A, Sjöholm K, Waldemarson S, Happonen L, Karlsson C, Persson H, Malmström J. Development of Phage-Based Antibody Fragment Reagents for Affinity Enrichment of Bacterial Immunoglobulin G Binding Proteins. J Proteome Res 2015; 14:4704-13. [PMID: 26452057 DOI: 10.1021/acs.jproteome.5b00585] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Disease and death caused by bacterial infections are global health problems. Effective bacterial strategies are required to promote survival and proliferation within a human host, and it is important to explore how this adaption occurs. However, the detection and quantification of bacterial virulence factors in complex biological samples are technically demanding challenges. These can be addressed by combining targeted affinity enrichment of antibodies with the sensitivity of liquid chromatography-selected reaction monitoring mass spectrometry (LC-SRM MS). However, many virulence factors have evolved properties that make specific detection by conventional antibodies difficult. We here present an antibody format that is particularly well suited for detection and analysis of immunoglobulin G (IgG)-binding virulence factors. As proof of concept, we have generated single chain fragment variable (scFv) antibodies that specifically target the IgG-binding surface proteins M1 and H of Streptococcus pyogenes. The binding ability of the developed scFv is demonstrated against both recombinant soluble protein M1 and H as well as the intact surface proteins on a wild-type S. pyogenes strain. Additionally, the capacity of the developed scFv antibodies to enrich their target proteins from both simple and complex backgrounds, thereby allowing for detection and quantification with LC-SRM MS, was demonstrated. We have established a workflow that allows for affinity enrichment of bacterial virulence factors.
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Affiliation(s)
- Anna Säll
- Department of Immunotechnology, Lund University , Medicon Village (House 406), SE 223 81, Lund, Sweden
| | - Kristoffer Sjöholm
- Department of Immunotechnology, Lund University , Medicon Village (House 406), SE 223 81, Lund, Sweden
| | - Sofia Waldemarson
- Department of Immunotechnology, Lund University , Medicon Village (House 406), SE 223 81, Lund, Sweden
| | - Lotta Happonen
- Division of Infection Medicine, Department of Clinical Sciences, Lund University , SE 221 00, Lund, Sweden
| | - Christofer Karlsson
- Division of Infection Medicine, Department of Clinical Sciences, Lund University , SE 221 00, Lund, Sweden
| | - Helena Persson
- Department of Immunotechnology, Lund University , Medicon Village (House 406), SE 223 81, Lund, Sweden.,Science for Life Laboratory, Royal Institute of Technology , 17121 Stockholm, Sweden
| | - Johan Malmström
- Division of Infection Medicine, Department of Clinical Sciences, Lund University , SE 221 00, Lund, Sweden
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38
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Lood R, Waldetoft KW, Nordenfelt P. Localization-triggered bacterial pathogenesis. Future Microbiol 2015; 10:1659-68. [PMID: 26437846 DOI: 10.2217/fmb.15.89] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Bacterial infections are becoming an increasing problem worldwide and there is a need for a deeper understanding of how bacteria turn pathogenic. Here, we suggest that one answer may be found by taking into account the localization of the bacteria, both at an anatomical level and at a microenvironment level. Both commensals and traditional pathogens alter their interaction with the human host depending on the local surroundings--turning either more or less virulent. These localization effects could derive from the characteristics of different anatomical sites but also from local differences within a microenvironment. In order to understand the adaptive functions of bacterial virulence factors, we need to study the bacteria in the environments where they have evolved.
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Affiliation(s)
- Rolf Lood
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, SE-221 84 Lund, Sweden
| | | | - Pontus Nordenfelt
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, SE-221 84 Lund, Sweden
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39
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Vigilant keratinocytes trigger pathogen-associated molecular pattern signaling in response to streptococcal M1 protein. Infect Immun 2015; 83:4673-81. [PMID: 26416902 DOI: 10.1128/iai.00887-15] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 09/13/2015] [Indexed: 12/22/2022] Open
Abstract
The human skin exerts many functions in order to maintain its barrier integrity and protect the host from invading microorganisms. One such pathogen is Streptococcus pyogenes, which can cause a variety of superficial skin wounds that may eventually progress into invasive deep soft tissue infections. Here we show that keratinocytes recognize soluble M1 protein, a streptococcal virulence factor, as a pathogen-associated molecular pattern to release alarming inflammatory responses. We found that this interaction initiates an inflammatory intracellular signaling cascade involving the activation of the mitogen-activated protein kinases extracellular signal-regulated kinase (ERK), p38, and Jun N-terminal protein kinase and the subsequent induction and mobilization of the transcription factors NF-κB and AP-1. We also determined the imprint of the inflammatory mediators released, such as interleukin-8 (IL-8), growth-related oncogene alpha, migration inhibitory factor, extracellular matrix metalloproteinase inducer, IL-1α, IL-1 receptor a, and ST2, in response to streptococcal M1 protein. The expression of IL-8 is dependent on Toll-like receptor 2 activity and subsequent activation of the mitogen-activated protein kinases ERK and p38. Notably, this signaling seems to be distinct for IL-8 release, and it is not shared with the other inflammatory mediators. We conclude that keratinocytes participate in a proinflammatory manner in streptococcal pattern recognition and that expression of the chemoattractant IL-8 by keratinocytes constitutes an important protective mechanism against streptococcal M1 protein.
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40
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Lannergård J, Kristensen BM, Gustafsson MCU, Persson JJ, Norrby-Teglund A, Stålhammar-Carlemalm M, Lindahl G. Sequence variability is correlated with weak immunogenicity in Streptococcus pyogenes M protein. Microbiologyopen 2015; 4:774-89. [PMID: 26175306 PMCID: PMC4618610 DOI: 10.1002/mbo3.278] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 06/18/2015] [Indexed: 11/06/2022] Open
Abstract
The M protein of Streptococcus pyogenes, a major bacterial virulence factor, has an amino-terminal hypervariable region (HVR) that is a target for type-specific protective antibodies. Intriguingly, the HVR elicits a weak antibody response, indicating that it escapes host immunity by two mechanisms, sequence variability and weak immunogenicity. However, the properties influencing the immunogenicity of regions in an M protein remain poorly understood. Here, we studied the antibody response to different regions of the classical M1 and M5 proteins, in which not only the HVR but also the adjacent fibrinogen-binding B repeat region exhibits extensive sequence divergence. Analysis of antisera from S. pyogenes-infected patients, infected mice, and immunized mice showed that both the HVR and the B repeat region elicited weak antibody responses, while the conserved carboxy-terminal part was immunodominant. Thus, we identified a correlation between sequence variability and weak immunogenicity for M protein regions. A potential explanation for the weak immunogenicity was provided by the demonstration that protease digestion selectively eliminated the HVR-B part from whole M protein-expressing bacteria. These data support a coherent model, in which the entire variable HVR-B part evades antibody attack, not only by sequence variability but also by weak immunogenicity resulting from protease attack.
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Affiliation(s)
- Jonas Lannergård
- Department of Laboratory Medicine, Lund University, Lund, Sweden.,Department of Veterinary Disease Biology, University of Copenhagen, Frederiksberg C, Denmark
| | | | | | - Jenny J Persson
- Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Anna Norrby-Teglund
- Center for Infectious Medicine, Karolinska Institutet, Huddinge University Hospital, Stockholm, Sweden
| | | | - Gunnar Lindahl
- Department of Laboratory Medicine, Lund University, Lund, Sweden.,Department of Veterinary Disease Biology, University of Copenhagen, Frederiksberg C, Denmark
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41
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Fiebig A, Loof TG, Babbar A, Itzek A, Koehorst JJ, Schaap PJ, Nitsche-Schmitz DP. Comparative genomics of Streptococcus pyogenes M1 isolates differing in virulence and propensity to cause systemic infection in mice. Int J Med Microbiol 2015; 305:532-43. [PMID: 26129624 DOI: 10.1016/j.ijmm.2015.06.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 06/15/2015] [Accepted: 06/19/2015] [Indexed: 12/14/2022] Open
Abstract
Streptococcus pyogenes serotype M1 is a frequent cause of severe infections in humans. Some M1 isolates are pathogenic in mice and used in studies on infection pathogenesis. We observed marked differences in murine infections caused by M1 strain SF370, 5448, 5448AP or AP1 which prompted us to sequence the whole genome of isolates 5448 and AP1 for comparative analysis. Strain 5448 is known to acquire inactivating mutations in the CovRS two-component system during mouse infection, producing hypervirulent progeny such as 5448AP. Isolates AP1 and 5448AP, more than 5448, caused disseminating infections that became systemic and lethal. SF370 was not pathogenic. Phages caused gross genetic differences and increased the gene content of AP1 by 8% as compared to 5448 and SF370. Each of six examined M1 genomes contained two CRISPR-Cas systems. Phage insertion destroyed a type II CRISPR-Cas system in AP1 and other strains of serotypes M1, M3, M6 and M24, but not in M1 strains 5448, SF370, MGAS5005, A20 or M1 476. A resulting impaired defence against invading genetic elements could have led to the wealth of phages in AP1. AP1 lacks genetic features of the MGAS5005-like clonal complex including the streptodornase that drives selection for hypervirulent clones with inactivated CovRS system. Still, inactivating mutations in covS were a common genetic feature of AP1 and the MGAS5005-like isolate 5448AP. Abolished expression of the cysteine proteinase SpeB, due to CovRS inactivation could be a common cause for hypervirulence of the two isolates. Moreover, an additional protein H-coding gene and a mutation in the regulator gene rofA distinguished AP1 form other M1 isolates. In conclusion, hypervirulence of S. pyogenes M1 in mice is not limited to the MGAS5005-like genotype.
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Affiliation(s)
- Anne Fiebig
- Infection Immunology Research Group, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Torsten G Loof
- Infection Immunology Research Group, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Anshu Babbar
- Microbial Interactions and Processes Research Group, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Andreas Itzek
- Microbial Interactions and Processes Research Group, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Jasper J Koehorst
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research Centre, Wageningen, the Netherlands
| | - Peter J Schaap
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research Centre, Wageningen, the Netherlands
| | - D Patric Nitsche-Schmitz
- Microbial Interactions and Processes Research Group, Helmholtz Centre for Infection Research, Braunschweig, Germany.
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42
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Chandrahas V, Glinton K, Liang Z, Donahue DL, Ploplis VA, Castellino FJ. Direct Host Plasminogen Binding to Bacterial Surface M-protein in Pattern D Strains of Streptococcus pyogenes Is Required for Activation by Its Natural Coinherited SK2b Protein. J Biol Chem 2015; 290:18833-42. [PMID: 26070561 DOI: 10.1074/jbc.m115.655365] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Indexed: 11/06/2022] Open
Abstract
Streptokinase (SK), secreted by Group A Streptococcus (GAS), is a single-chain ∼47-kDa protein containing three consecutive primary sequence regions that comprise its α, β, and γ modules. Phylogenetic analyses of the variable β-domain sequences from different GAS strains suggest that SKs can be arranged into two clusters, SK1 and SK2, with a subdivision of SK2 into SK2a and SK2b. SK2b is secreted by skin-tropic Pattern D M-protein strains that also express plasminogen (human Pg (hPg)) binding Group A streptococcal M-protein (PAM) as its major cell surface M-protein. SK2a-expressing strains are associated with nasopharynx tropicity, and many of these strains express human fibrinogen (hFg) binding Pattern A-C M-proteins, e.g. M1. PAM interacts with hPg directly, whereas M1 binds to hPg indirectly via M1-bound hFg. Subsequently, SK is secreted by GAS and activates hPg to plasmin (hPm), thus generating a proteolytic surface on GAS that enhances its dissemination. Due to these different modes of hPg/hPm recognition by GAS, full characterizations of the mechanisms of activation of hPg by SK2a and SK2b and their roles in GAS virulence are important topics. To more fully examine these subjects, isogenic chimeric SK- and M-protein-containing GAS strains were generated, and the virulence of these chimeric strains were analyzed in mice. We show that SK and M-protein alterations influenced the virulence of GAS and were associated with the different natures of hPg activation and hPm binding. These studies demonstrate that GAS virulence can be explained by disparate hPg activation by SK2a and SK2b coupled with the coinherited M-proteins of these strains.
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Affiliation(s)
- Vishwanatha Chandrahas
- From the W. M. Keck Center for Transgene Research and Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556
| | - Kristofor Glinton
- From the W. M. Keck Center for Transgene Research and Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556
| | - Zhong Liang
- From the W. M. Keck Center for Transgene Research and Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556
| | - Deborah L Donahue
- From the W. M. Keck Center for Transgene Research and Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556
| | - Victoria A Ploplis
- From the W. M. Keck Center for Transgene Research and Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556
| | - Francis J Castellino
- From the W. M. Keck Center for Transgene Research and Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556
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43
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McNeilly CL, McMillan DJ. Horizontal gene transfer and recombination in Streptococcus dysgalactiae subsp. equisimilis. Front Microbiol 2014; 5:676. [PMID: 25566202 PMCID: PMC4266089 DOI: 10.3389/fmicb.2014.00676] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 11/19/2014] [Indexed: 11/13/2022] Open
Abstract
Streptococcus dysgalactiae subsp. equisimilis (SDSE) is a human pathogen that colonizes the skin or throat, and causes a range of diseases from relatively benign pharyngitis to potentially fatal invasive diseases. While not as virulent as the close relative Streptococcus pyogenes the two share a number of virulence factors and are known to coexist in a human host. Both pre- and post-genomic studies have revealed that horizontal gene transfer (HGT) and recombination occurs between these two organisms and plays a major role in shaping the population structure of SDSE. This review summarizes our current knowledge of HGT and recombination in the evolution of SDSE.
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Affiliation(s)
- Celia L McNeilly
- Bacterial Pathogenesis Laboratory, QIMR Berghofer Medical Research Institute , Herston, QLD, Australia
| | - David J McMillan
- Inflammation and Healing Research Cluster, School of Health and Sport Sciences, University of the Sunshine Coast , Maroochydore, QLD, Australia
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44
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Sanderson-Smith M, De Oliveira DMP, Guglielmini J, McMillan DJ, Vu T, Holien JK, Henningham A, Steer AC, Bessen DE, Dale JB, Curtis N, Beall BW, Walker MJ, Parker MW, Carapetis JR, Van Melderen L, Sriprakash KS, Smeesters PR. A systematic and functional classification of Streptococcus pyogenes that serves as a new tool for molecular typing and vaccine development. J Infect Dis 2014; 210:1325-38. [PMID: 24799598 PMCID: PMC6083926 DOI: 10.1093/infdis/jiu260] [Citation(s) in RCA: 228] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Accepted: 04/25/2014] [Indexed: 11/12/2022] Open
Abstract
Streptococcus pyogenes ranks among the main causes of mortality from bacterial infections worldwide. Currently there is no vaccine to prevent diseases such as rheumatic heart disease and invasive streptococcal infection. The streptococcal M protein that is used as the substrate for epidemiological typing is both a virulence factor and a vaccine antigen. Over 220 variants of this protein have been described, making comparisons between proteins difficult, and hindering M protein-based vaccine development. A functional classification based on 48 emm-clusters containing closely related M proteins that share binding and structural properties is proposed. The need for a paradigm shift from type-specific immunity against S. pyogenes to emm-cluster based immunity for this bacterium should be further investigated. Implementation of this emm-cluster-based system as a standard typing scheme for S. pyogenes will facilitate the design of future studies of M protein function, streptococcal virulence, epidemiological surveillance, and vaccine development.
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Affiliation(s)
- Martina Sanderson-Smith
- Illawarra Health and Medical Research Institute and School of Biological Sciences, University of Wollongong, Australia
| | - David M. P. De Oliveira
- Illawarra Health and Medical Research Institute and School of Biological Sciences, University of Wollongong, Australia
| | - Julien Guglielmini
- Microbial Evolutionary Genomics, Département Génomes et Génétique, Institut Pasteur
- CNRS, UMR3525, Paris, France
| | - David J. McMillan
- Bacterial Pathogenesis Laboratory, QIMR Berghofer Medical Research Institute, Brisbane
- Inflammation and Healing Research Cluster, School of Health and Sports Sciences, University of the Sunshine Coast, Sippy Downs, Australia
| | - Therese Vu
- Bacterial Pathogenesis Laboratory, QIMR Berghofer Medical Research Institute, Brisbane
- Laboratoire de Génétique et Physiologie Bactérienne, Institut de Biologie et de Médecine Moléculaires, Faculté des Sciences, Université Libre de Bruxelles, Gosselies, Belgium
| | - Jessica K. Holien
- Biota Structural Biology Laboratory, ACRF Rational Drug Discovery Centre, St. Vincent's Institute of Medical Research, Melbourne
| | - Anna Henningham
- School of Chemistry and Molecular Biosciences and Australian Infectious Diseases Research Centre, University of Queensland, Brisbane
| | - Andrew C. Steer
- Murdoch Children Research Institute
- Centre for International Child Health, The University of Melbourne
- Department of General Medicine, Royal Children's Hospital Melbourne, Australia
| | - Debra E. Bessen
- Department of Microbiology and Immunology, New York Medical College, Valhalla
| | - James B. Dale
- Department of Medicine, The University of Tennessee Health Science Center
- Department of Veterans Affairs Medical Center, and
- Department of Microbiology, Immunology and Biochemistry, The University of Tennessee Health Science Center, Memphis
| | - Nigel Curtis
- Murdoch Children Research Institute
- Infectious Diseases Unit, Royal Children's Hospital Melbourne
- Department of Paediatrics, The University of Melbourne, Australia
| | - Bernard W. Beall
- Respiratory Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Mark J. Walker
- School of Chemistry and Molecular Biosciences and Australian Infectious Diseases Research Centre, University of Queensland, Brisbane
| | - Michael W. Parker
- Biota Structural Biology Laboratory, ACRF Rational Drug Discovery Centre, St. Vincent's Institute of Medical Research, Melbourne
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne
| | - Jonathan R. Carapetis
- Telethon Institute for Child Health Research, Centre for Child Health Research, University of Western Australia, Perth
| | - Laurence Van Melderen
- Laboratoire de Génétique et Physiologie Bactérienne, Institut de Biologie et de Médecine Moléculaires, Faculté des Sciences, Université Libre de Bruxelles, Gosselies, Belgium
| | - Kadaba S. Sriprakash
- Bacterial Pathogenesis Laboratory, QIMR Berghofer Medical Research Institute, Brisbane
| | - Pierre R. Smeesters
- Laboratoire de Génétique et Physiologie Bactérienne, Institut de Biologie et de Médecine Moléculaires, Faculté des Sciences, Université Libre de Bruxelles, Gosselies, Belgium
- Murdoch Children Research Institute
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45
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Sjöholm K, Karlsson C, Linder A, Malmström J. A comprehensive analysis of the Streptococcus pyogenes and human plasma protein interaction network. MOLECULAR BIOSYSTEMS 2014; 10:1698-708. [PMID: 24525632 DOI: 10.1039/c3mb70555b] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Streptococcus pyogenes is a major human bacterial pathogen responsible for severe and invasive disease associated with high mortality rates. The bacterium interacts with several human blood plasma proteins and clarifying these interactions and their biological consequences will help to explain the progression from mild to severe infections. In this study, we used a combination of mass spectrometry (MS) based techniques to comprehensively quantify the components of the S. pyogenes-plasma protein interaction network. From an initial list of 181 interacting human plasma proteins defined using liquid chromatography (LC)-MS/MS analysis we further subdivided the interacting protein list using selected reaction monitoring (SRM) depending on the level of enrichment and protein concentration on the bacterial surface. The combination of MS methods revealed several previously characterized interactions between the S. pyogenes surface and human plasma along with many more, so far uncharacterised, possible plasma protein interactions with S. pyogenes. In follow-up experiments, the combination of MS techniques was applied to study differences in protein binding to a S. pyogenes wild type strain and an isogenic mutant lacking several important virulence factors, and a unique pair of invasive and non-invasive S. pyogenes isolates from the same patient. Comparing the plasma protein-binding properties of the wild type and the mutant and the invasive and non-invasive S. pyogenes bacteria revealed considerable differences, underlining the significance of these protein interactions. The results also demonstrate the power of the developed mass spectrometry method to investigate host-microbial relationships with a large proteomics depth and high quantitative accuracy.
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Affiliation(s)
- Kristoffer Sjöholm
- Department of Immunotechnology, Faculty of Engineering, Lund University, Sweden
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46
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Ermert D, Weckel A, Agarwal V, Frick IM, Björck L, Blom AM. Binding of complement inhibitor C4b-binding protein to a highly virulent Streptococcus pyogenes M1 strain is mediated by protein H and enhances adhesion to and invasion of endothelial cells. J Biol Chem 2013; 288:32172-32183. [PMID: 24064215 DOI: 10.1074/jbc.m113.502955] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Streptococcus pyogenes AP1, a strain of the highly virulent M1 serotype, uses exclusively protein H to bind the complement inhibitor C4b-binding protein (C4BP). We found a strong correlation between the ability of AP1 and its isogenic mutants lacking protein H to inhibit opsonization with complement C3b and binding of C4BP. C4BP bound to immobilized protein H or AP1 bacteria retained its cofactor activity for degradation of (125)I-C4b. Furthermore, C4b deposited from serum onto AP1 bacterial surfaces was processed into C4c/C4d fragments, which did not occur on strains unable to bind C4BP. Recombinant C4BP mutants, which (i) lack certain CCP domains or (ii) have mutations in single aa as well as (iii) mutants with additional aa between different CCP domains were used to determine that the binding is mainly mediated by a patch of positively charged amino acid residues at the interface of domains CCP1 and CCP2. Using recombinant protein H fragments, we narrowed down the binding site to the N-terminal domain A. With a peptide microarray, we identified one single 18-amino acid-long peptide comprising residues 92-109, which specifically bound C4BP. Biacore was used to determine KD = 6 × 10(-7) M between protein H and a single subunit of C4BP. C4BP binding also correlated with elevated levels of adhesion and invasion to endothelial cells. Taken together, we identified the molecular basis of C4BP-protein H interaction and found that it is not only important for decreased opsonization but also for invasion of endothelial cells by S. pyogenes.
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Affiliation(s)
- David Ermert
- From the Department of Laboratory Medicine, Medical Protein Chemistry, Lund University, SE-205 02 Malmö, Sweden
| | - Antonin Weckel
- From the Department of Laboratory Medicine, Medical Protein Chemistry, Lund University, SE-205 02 Malmö, Sweden
| | - Vaibhav Agarwal
- From the Department of Laboratory Medicine, Medical Protein Chemistry, Lund University, SE-205 02 Malmö, Sweden
| | - Inga-Maria Frick
- Department of Clinical Sciences, Division of Infection Medicine, Lund University, SE-221 00 Lund, Sweden
| | - Lars Björck
- Department of Clinical Sciences, Division of Infection Medicine, Lund University, SE-221 00 Lund, Sweden
| | - Anna M Blom
- From the Department of Laboratory Medicine, Medical Protein Chemistry, Lund University, SE-205 02 Malmö, Sweden.
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47
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Oehmcke S, Westman J, Malmström J, Mörgelin M, Olin AI, Kreikemeyer B, Herwald H. A novel role for pro-coagulant microvesicles in the early host defense against streptococcus pyogenes. PLoS Pathog 2013; 9:e1003529. [PMID: 23935504 PMCID: PMC3731245 DOI: 10.1371/journal.ppat.1003529] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Accepted: 06/15/2013] [Indexed: 01/30/2023] Open
Abstract
Previous studies have shown that stimulation of whole blood or peripheral blood mononuclear cells with bacterial virulence factors results in the sequestration of pro-coagulant microvesicles (MVs). These particles explore their clotting activity via the extrinsic and intrinsic pathway of coagulation; however, their pathophysiological role in infectious diseases remains enigmatic. Here we describe that the interaction of pro-coagulant MVs with bacteria of the species Streptococcus pyogenes is part of the early immune response to the invading pathogen. As shown by negative staining electron microscopy and clotting assays, pro-coagulant MVs bind in the presence of plasma to the bacterial surface. Fibrinogen was identified as a linker that, through binding to the M1 protein of S. pyogenes, allows the opsonization of the bacteria by MVs. Surface plasmon resonance analysis revealed a strong interaction between pro-coagulant MVs and fibrinogen with a KD value in the nanomolar range. When performing a mass-spectrometry-based strategy to determine the protein quantity, a significant up-regulation of the fibrinogen-binding integrins CD18 and CD11b on pro-coagulant MVs was recorded. Finally we show that plasma clots induced by pro-coagulant MVs are able to prevent bacterial dissemination and possess antimicrobial activity. These findings were confirmed by in vivo experiments, as local treatment with pro-coagulant MVs dampens bacterial spreading to other organs and improved survival in an invasive streptococcal mouse model of infection. Taken together, our data implicate that pro-coagulant MVs play an important role in the early response of the innate immune system in infectious diseases. The coagulation system is much more than a passive bystander in our defense against exogenous microorganisms. Over the last years there has been a growing body of evidence pointing to an integral part of coagulation in innate immunity and a special focus has been on bacterial entrapment in a fibrin network. However, thus far, pro-coagulant MVs have not been discussed in this context, though it is known that their numbers can dramatically increase in many pathological conditions, including severe infectious diseases. In the present study we see a significant increase of pro-coagulant MVs in an invasive streptococcal mouse model, suggesting that their release is an immune response to the infection. We find that pro-coagulant MVs bind to Streptococcus pyogenes and promote clotting, entrapment, and killing of the bacteria in a fibrin network. As a proof of concept pro-coagulant MVs were applied as local treatment in the streptococcal infection model, and it was demonstrated that this led to a significantly improved survival in mice.
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Affiliation(s)
- Sonja Oehmcke
- University Medicine, Institute of Medical Microbiology, Virology and Hygiene, Rostock University, Rostock, Germany.
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48
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Nordenfelt P, Waldemarson S, Linder A, Mörgelin M, Karlsson C, Malmström J, Björck L. Antibody orientation at bacterial surfaces is related to invasive infection. ACTA ACUST UNITED AC 2012; 209:2367-81. [PMID: 23230002 PMCID: PMC3526361 DOI: 10.1084/jem.20120325] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Several of the most significant bacterial pathogens in humans, including Streptococcus pyogenes, express surface proteins that bind IgG antibodies via their fragment crystallizable (Fc) region, and the dogma is that this protects the bacteria against phagocytic killing in blood. However, analysis of samples from a patient with invasive S. pyogenes infection revealed dramatic differences in the presence and orientation of IgG antibodies at the surface of bacteria from different sites. In the throat, IgG was mostly bound to the bacterial surface via Fc, whereas in the blood IgG was mostly bound via fragment antigen-binding (Fab). In infected and necrotic tissue, the Fc-binding proteins were removed from the bacterial surface. Further investigation showed that efficient bacterial IgGFc-binding occurs only in IgG-poor environments, such as saliva. As a consequence, the bacteria are protected against phagocytic killing, whereas in blood plasma where the concentration of IgG is high, the antibodies preferentially bind via Fab, facilitating opsonization and bacterial killing. IgG-poor environments represent the natural habitat for IgGFc-binding bacteria, and IgGFc-binding proteins may have evolved to execute their function in such environments. The lack of protection in plasma also helps to explain why cases of severe invasive infections with IgGFc-binding bacteria are so rare compared with superficial and uncomplicated infections.
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Affiliation(s)
- Pontus Nordenfelt
- Department of Clinical Sciences, Faculty of Medicine, Lund University, Lund, Sweden.
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49
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Nordenfelt P, Grinstein S, Björck L, Tapper H. V-ATPase-mediated phagosomal acidification is impaired by Streptococcus pyogenes through Mga-regulated surface proteins. Microbes Infect 2012; 14:1319-29. [PMID: 22981599 DOI: 10.1016/j.micinf.2012.08.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Revised: 08/10/2012] [Accepted: 08/13/2012] [Indexed: 12/22/2022]
Abstract
Streptococcus pyogenes, a significant bacterial pathogen in humans, interferes with the membrane traffic of human neutrophils and survives following phagocytosis. The mechanism(s) behind this property is not known, but in contrast to wild-type bacteria, mutant bacteria lacking virulence factors regulated by the transcriptional regulator Mga, are phagocytosed and killed. In the present work we investigated whether differences in phagosomal acidification may contribute to this difference. Phagosomal pH in neutrophil-differentiated HL-60 cells was studied by fluorescence ratio imaging, and phagosomes containing wild-type S. pyogenes bacteria of the M1 serotype exhibited little or no acidification, whereas Mga mutant bacteria were found in more acidic phagosomes. With phagosomes containing these bacteria, proton delivery was inhibited by adding folimycin, a vacuolar-type adenosine triphosphatase (V-ATPase) inhibitor. This inhibitor had no effect on phagosomes containing wild-type bacteria, indicating either inactivation or removal of V-ATPases by the bacteria. Analysis of isolated bacteria-containing phagosomes confirmed the latter scenario and showed a more efficient delivery of V-ATPases to phagosomes containing Mga mutant bacteria. The results demonstrate that V-ATPase-mediated phagosomal proton delivery is reduced during phagocytosis of wild-type S. pyogenes, leading to impaired acidification, and that surface proteins of the mga regulon are responsible for this effect.
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Affiliation(s)
- Pontus Nordenfelt
- Division of Infection Medicine, Department of Clinical Sciences, BMC, B14, Lund University, SE-221 84 Lund, Sweden.
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50
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van Os GMA, Meijers JCM, Agar Ç, Seron MV, Marquart JA, Åkesson P, Urbanus RT, Derksen RHWM, Herwald H, Mörgelin M, D E Groot PG. Induction of anti-β2 -glycoprotein I autoantibodies in mice by protein H of Streptococcus pyogenes. J Thromb Haemost 2011; 9:2447-56. [PMID: 21985124 DOI: 10.1111/j.1538-7836.2011.04532.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND The antiphospholipid syndrome (APS) is characterized by the persistent presence of anti-β(2) -glycoprotein I (β(2) -GPI) autoantibodies. β(2) -GPI can exist in two conformations. In plasma it is a circular protein, whereas it adopts a fish-hook conformation after binding to phospholipids. Only the latter conformation is recognized by patient antibodies. β(2) -GPI has been shown to interact with Streptococcus pyogenes. OBJECTIVE To evaluate the potential of S. pyogenes-derived proteins to induce anti-β(2) -GPI autoantibodies. METHODS AND RESULTS Four S. pyogenes surface proteins (M1 protein, protein H, streptococcal collagen-like protein A [SclA], and streptococcal collagen-like protein B [SclB]) were found to interact with β(2) -GPI. Only binding to protein H induces a conformational change in β(2) -GPI, thereby exposing a cryptic epitope for APS-related autoantibodies. Mice were injected with the four proteins. Only mice injected with protein H developed antibodies against the patient antibody-related epitope in domain I of β(2) -GPI. Patients with pharyngotonsillitis caused by S. pyogenes who developed anti-protein H antibodies also generated anti-β(2) -GPI antibodies. CONCLUSIONS Our study has demonstrated that a bacterial protein can induce a conformational change in β(2) -GPI, resulting in the formation of antiβ(2) -GPI autoantibodies. This constitutes a novel mechanism for the formation of anti-β(2) -GPI autoantibodies.
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Affiliation(s)
- G M A van Os
- Department of Clinical Chemistry and Hematology, University Medical Center, CX, Utrecht, the Netherlands
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