1
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Izadi A, Karami Y, Bratanis E, Wrighton S, Khakzad H, Nyblom M, Olofsson B, Happonen L, Tang D, Sundwall M, Godzwon M, Chao Y, Toledo AG, Schmidt T, Ohlin M, Nilges M, Malmström J, Bahnan W, Shannon O, Malmström L, Nordenfelt P. The hinge-engineered IgG1-IgG3 hybrid subclass IgGh 47 potently enhances Fc-mediated function of anti-streptococcal and SARS-CoV-2 antibodies. Nat Commun 2024; 15:3600. [PMID: 38678029 PMCID: PMC11055898 DOI: 10.1038/s41467-024-47928-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 04/15/2024] [Indexed: 04/29/2024] Open
Abstract
Streptococcus pyogenes can cause invasive disease with high mortality despite adequate antibiotic treatments. To address this unmet need, we have previously generated an opsonic IgG1 monoclonal antibody, Ab25, targeting the bacterial M protein. Here, we engineer the IgG2-4 subclasses of Ab25. Despite having reduced binding, the IgG3 version promotes stronger phagocytosis of bacteria. Using atomic simulations, we show that IgG3's Fc tail has extensive movement in 3D space due to its extended hinge region, possibly facilitating interactions with immune cells. We replaced the hinge of IgG1 with four different IgG3-hinge segment subclasses, IgGhxx. Hinge-engineering does not diminish binding as with IgG3 but enhances opsonic function, where a 47 amino acid hinge is comparable to IgG3 in function. IgGh47 shows improved protection against S. pyogenes in a systemic infection mouse model, suggesting that IgGh47 has promise as a preclinical therapeutic candidate. Importantly, the enhanced opsonic function of IgGh47 is generalizable to diverse S. pyogenes strains from clinical isolates. We generated IgGh47 versions of anti-SARS-CoV-2 mAbs to broaden the biological applicability, and these also exhibit strongly enhanced opsonic function compared to the IgG1 subclass. The improved function of the IgGh47 subclass in two distant biological systems provides new insights into antibody function.
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Affiliation(s)
- Arman Izadi
- Department of Clinical Sciences Lund, Infection Medicine, Faculty of Medicine, Lund University, Lund, Sweden
| | - Yasaman Karami
- Université de Lorraine, CNRS, Inria, LORIA, F-54000, Nancy, France
- Institut Pasteur, Université Paris cite, CNRS UMR3528, Structural Bioinformatics Unit, Department of Structural Biology and Chemistry, F-75015, Paris, France
| | - Eleni Bratanis
- Department of Clinical Sciences Lund, Infection Medicine, Faculty of Medicine, Lund University, Lund, Sweden
| | - Sebastian Wrighton
- Department of Clinical Sciences Lund, Infection Medicine, Faculty of Medicine, Lund University, Lund, Sweden
| | - Hamed Khakzad
- Université de Lorraine, CNRS, Inria, LORIA, F-54000, Nancy, France
| | - Maria Nyblom
- Department of Biology & Lund Protein Production Platform (LP3), Lund University, Lund, Sweden
| | - Berit Olofsson
- Department of Clinical Sciences Lund, Infection Medicine, Faculty of Medicine, Lund University, Lund, Sweden
| | - Lotta Happonen
- Department of Clinical Sciences Lund, Infection Medicine, Faculty of Medicine, Lund University, Lund, Sweden
| | - Di Tang
- Department of Clinical Sciences Lund, Infection Medicine, Faculty of Medicine, Lund University, Lund, Sweden
| | - Martin Sundwall
- Department of Clinical Sciences Lund, Infection Medicine, Faculty of Medicine, Lund University, Lund, Sweden
| | - Magdalena Godzwon
- Department of Immunotechnology and SciLifeLab Drug Discovery and Development Platform, Lund University, Lund, Sweden
| | - Yashuan Chao
- Department of Clinical Sciences Lund, Infection Medicine, Faculty of Medicine, Lund University, Lund, Sweden
| | - Alejandro Gomez Toledo
- Department of Clinical Sciences Lund, Infection Medicine, Faculty of Medicine, Lund University, Lund, Sweden
| | - Tobias Schmidt
- Department of Clinical Sciences Lund, Division of Pediatrics, Faculty of Medicine, Lund University, Lund, Sweden
| | - Mats Ohlin
- Department of Immunotechnology and SciLifeLab Drug Discovery and Development Platform, Lund University, Lund, Sweden
| | - Michael Nilges
- Institut Pasteur, Université Paris cite, CNRS UMR3528, Structural Bioinformatics Unit, Department of Structural Biology and Chemistry, F-75015, Paris, France
| | - Johan Malmström
- Department of Clinical Sciences Lund, Infection Medicine, Faculty of Medicine, Lund University, Lund, Sweden
| | - Wael Bahnan
- Department of Clinical Sciences Lund, Infection Medicine, Faculty of Medicine, Lund University, Lund, Sweden
| | - Oonagh Shannon
- Department of Clinical Sciences Lund, Infection Medicine, Faculty of Medicine, Lund University, Lund, Sweden
- Section for Oral Biology and Pathology, Faculty of Odontology, Malmö University, Malmö, Sweden
| | - Lars Malmström
- Department of Clinical Sciences Lund, Infection Medicine, Faculty of Medicine, Lund University, Lund, Sweden
| | - Pontus Nordenfelt
- Department of Clinical Sciences Lund, Infection Medicine, Faculty of Medicine, Lund University, Lund, Sweden.
- Department of Laboratory Medicine, Clinical Microbiology, Skåne University Hospital Lund, Lund University, Lund, Sweden.
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2
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Su MSW, Cheng YL, Lin YS, Wu JJ. Interplay between group A Streptococcus and host innate immune responses. Microbiol Mol Biol Rev 2024; 88:e0005222. [PMID: 38451081 PMCID: PMC10966951 DOI: 10.1128/mmbr.00052-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2024] Open
Abstract
SUMMARYGroup A Streptococcus (GAS), also known as Streptococcus pyogenes, is a clinically well-adapted human pathogen that harbors rich virulence determinants contributing to a broad spectrum of diseases. GAS is capable of invading epithelial, endothelial, and professional phagocytic cells while evading host innate immune responses, including phagocytosis, selective autophagy, light chain 3-associated phagocytosis, and inflammation. However, without a more complete understanding of the different ways invasive GAS infections develop, it is difficult to appreciate how GAS survives and multiplies in host cells that have interactive immune networks. This review article attempts to provide an overview of the behaviors and mechanisms that allow pathogenic GAS to invade cells, along with the strategies that host cells practice to constrain GAS infection. We highlight the counteractions taken by GAS to apply virulence factors such as streptolysin O, nicotinamide-adenine dinucleotidase, and streptococcal pyrogenic exotoxin B as a hindrance to host innate immune responses.
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Affiliation(s)
- Marcia Shu-Wei Su
- Department of Medical Laboratory Science and Biotechnology, College of Medical and Health Sciences, Asia University, Taichung, Taiwan
- Department of Biotechnology and Laboratory Science in Medicine, College of Biomedical Science and Engineering, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Yi-Lin Cheng
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Department of Medical Laboratory Science and Biotechnology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Center of Infectious Disease and Signaling Research, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Yee-Shin Lin
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Center of Infectious Disease and Signaling Research, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Jiunn-Jong Wu
- Department of Medical Laboratory Science and Biotechnology, College of Medical and Health Sciences, Asia University, Taichung, Taiwan
- Department of Biotechnology and Laboratory Science in Medicine, College of Biomedical Science and Engineering, National Yang Ming Chiao Tung University, Taipei, Taiwan
- Department of Medical Research, China Medical University Hospital, China Medical University, Taichung, Taiwan
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3
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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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4
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Bergmann R, Schroedl W, Müller U, Baums CG. A distinct variant of the SzM protein of Streptococcus equi subsp. zooepidemicus recruits C1q independent of IgG binding and inhibits activation of the classical complement pathway. Virulence 2023; 14:2235461. [PMID: 37450582 PMCID: PMC10351459 DOI: 10.1080/21505594.2023.2235461] [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: 04/12/2023] [Revised: 06/29/2023] [Accepted: 07/06/2023] [Indexed: 07/18/2023] Open
Abstract
Streptococcus equi subsp. zooepidemicus (SEZ) is a major equine pathogen that causes pneumonia, abortion, and polyarthritis. It can also cause invasive infections in humans. SEZ expresses the M-like protein SzM, which recruits host proteins such as fibrinogen to the bacterial surface. Equine SEZ strain C2, which binds only comparably low amounts of human fibrinogen in comparison to human SEZ strain C33, was previously shown to proliferate in equine and human blood. As the expression of SzM_C2 was necessary for survival in blood, this study investigated the working hypothesis that SzM_C2 inhibits complement activation through a mechanism other than fibrinogen and non-immune immunoglobulin binding. Loss-of-function experiments showed that SEZ C2, but not C33, binds C1q via SzM in IgG-free human plasma. Furthermore, SzM C2 expression is necessary for recruiting purified human or equine C1q to the bacterial surface. Flow cytometry analysis demonstrated that SzM expression in SEZ C2 is crucial for the significant reduction of C3b labelling in human plasma. Addition of human plasma to immobilized rSzM_C2 and immobilized aggregated IgG led to binding of C1q, but only the latter activated the complement system, as shown by the detection of C4 deposition. Complement activation induced by aggregated IgG was significantly reduced if human plasma was pre-incubated with rSzM_C2. Furthermore, rSzM_C2, but not rSzM_C33, inhibited the activation of the classical complement pathway in human plasma, as determined in an erythrocyte lysis experiment. In conclusion, the immunoglobulin-independent binding of C1q to SzM_C2 is associated with complement inhibition.
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Affiliation(s)
- René Bergmann
- Institute of Bacteriology and Mycology, Centre for Infectious Diseases, Faculty of Veterinary Medicine, Leipzig University, Leipzig, Germany
| | - Wieland Schroedl
- Institute of Bacteriology and Mycology, Centre for Infectious Diseases, Faculty of Veterinary Medicine, Leipzig University, Leipzig, Germany
| | - Uwe Müller
- Institute of Immunology, Centre for Infectious Diseases, Faculty of Veterinary Medicine, Leipzig University, Leipzig, Germany
| | - Christoph Georg Baums
- Institute of Bacteriology and Mycology, Centre for Infectious Diseases, Faculty of Veterinary Medicine, Leipzig University, Leipzig, Germany
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5
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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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6
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Toledo AG, Bratanis E, Velásquez E, Chowdhury S, Olofsson B, Sorrentino JT, Karlsson C, Lewis NE, Esko JD, Collin M, Shannon O, Malmström J. Pathogen-driven degradation of endogenous and therapeutic antibodies during streptococcal infections. Nat Commun 2023; 14:6693. [PMID: 37872209 PMCID: PMC10593946 DOI: 10.1038/s41467-023-42572-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 10/16/2023] [Indexed: 10/25/2023] Open
Abstract
Group A streptococcus (GAS) is a major bacterial pathogen responsible for both local and systemic infections in humans. The molecular mechanisms that contribute to disease heterogeneity remain poorly understood. Here we show that the transition from a local to a systemic GAS infection is paralleled by pathogen-driven alterations in IgG homeostasis. Using animal models and a combination of sensitive proteomics and glycoproteomics readouts, we documented the progressive accumulation of IgG cleavage products in plasma, due to extensive enzymatic degradation triggered by GAS infection in vivo. The level of IgG degradation was modulated by the route of pathogen inoculation, and mechanistically linked to the combined activities of the bacterial protease IdeS and the endoglycosidase EndoS, upregulated during infection. Importantly, we show that these virulence factors can alter the structure and function of exogenous therapeutic IgG in vivo. These results shed light on the role of bacterial virulence factors in shaping GAS pathogenesis, and potentially blunting the efficacy of antimicrobial therapies.
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Affiliation(s)
- Alejandro Gomez Toledo
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Eleni Bratanis
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Erika Velásquez
- IPSC Laboratory for CNS Disease Modeling, Department of Experimental Medical Sciences, Lund University, Lund, Sweden
| | - Sounak Chowdhury
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Berit Olofsson
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - James T Sorrentino
- Bioinformatics and Systems Biology Graduate Program, University of California, San Diego, La Jolla, CA, USA
| | - Christofer Karlsson
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Nathan E Lewis
- Departments of Pediatrics and Bioengineering, University of California, San Diego, La Jolla, CA, USA
| | - Jeffrey D Esko
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Mattias Collin
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Oonagh Shannon
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Johan Malmström
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden.
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7
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Alamiri F, André O, De S, Nordenfelt P, Hakansson AP. Role of serotype and virulence determinants of Streptococcus pyogenes biofilm bacteria in internalization and persistence in epithelial cells in vitro. Front Cell Infect Microbiol 2023; 13:1146431. [PMID: 37234777 PMCID: PMC10206268 DOI: 10.3389/fcimb.2023.1146431] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 04/21/2023] [Indexed: 05/28/2023] Open
Abstract
Streptococcus pyogenes causes a multitude of local and systemic infections, the most common being pharyngitis in children. Recurrent pharyngeal infections are common and are thought to be due to the re-emergence of intracellular GAS upon completion of antibiotic treatment. The role of colonizing biofilm bacteria in this process is not fully clear. Here, live respiratory epithelial cells were inoculated with broth-grown or biofilm bacteria of different M-types, as well as with isogenic mutants lacking common virulence factors. All M-types tested adhered to and were internalized into epithelial cells. Interestingly, internalization and persistence of planktonic bacteria varied significantly between strains, whereas biofilm bacteria were internalized in similar and higher numbers, and all strains persisted beyond 44 hours, showing a more homogenous phenotype. The M3 protein, but not the M1 or M5 proteins, was required for optimal uptake and persistence of both planktonic and biofilm bacteria inside cells. Moreover, the high expression of capsule and SLO inhibited cellular uptake and capsule expression was required for intracellular survival. Streptolysin S was required for optimal uptake and persistence of M3 planktonic bacteria, whereas SpeB improved intracellular survival of biofilm bacteria. Microscopy of internalized bacteria showed that planktonic bacteria were internalized in lower numbers as individual or small clumps of bacteria in the cytoplasm, whereas GAS biofilm bacteria displayed a pattern of perinuclear localization of bacterial aggregates that affected actin structure. Using inhibitors targeting cellular uptake pathways, we confirmed that planktonic GAS mainly uses a clathrin-mediated uptake pathway that also required actin and dynamin. Clathrin was not involved in biofilm internalization, but internalization required actin rearrangement and PI3 kinase activity, possibly suggesting macropinocytosis. Together these results provide a better understanding of the potential mechanisms of uptake and survival of various phenotypes of GAS bacteria relevant for colonization and recurrent infection.
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Affiliation(s)
- Feiruz Alamiri
- Division of Experimental Infection Medicine, Department of Translational Medicine, Lund University, Malmö, Sweden
| | - Oscar André
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Supradipta De
- Division of Experimental Infection Medicine, Department of Translational Medicine, Lund University, Malmö, Sweden
| | - Pontus Nordenfelt
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Anders P. Hakansson
- Division of Experimental Infection Medicine, Department of Translational Medicine, Lund University, Malmö, Sweden
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8
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Wrighton S, Ahnlide VK, André O, Bahnan W, Nordenfelt P. Group A streptococci induce stronger M protein-fibronectin interaction when specific human antibodies are bound. Front Microbiol 2023; 14:1069789. [PMID: 36778879 PMCID: PMC9909010 DOI: 10.3389/fmicb.2023.1069789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 01/06/2023] [Indexed: 01/27/2023] Open
Abstract
Group A streptococcus (GAS) is a highly adapted, human-specific pathogen that is known to manipulate the immune system through various mechanisms. GAS' M protein constitutes a primary target of the immune system due to its spatial configuration and dominance on the bacterial surface. Antibody responses targeting the M protein have been shown to favor the conserved C region. Such antibodies (Abs) circumvent antigenic escape and efficiently bind to various M types. The ability of GAS to bind to fibronectin (Fn), a high molecular weight glycoprotein of the extracellular matrix, has long been known to be essential for the pathogen's evolutionary success and fitness. However, some strains lack the ability to efficiently bind Fn. Instead, they have been found to additionally bind Fn via the A-B domains of their M proteins. Here, we show that human Abs can induce increased Fn-binding affinity in M proteins, likely by enhancing the weak A-B domain binding. We found that this enhanced Fn binding leads to a reduction in Ab-mediated phagocytosis, indicating that this constitutes a GAS immune escape mechanism. We could show that the Fc domain of Abs is necessary to trigger this phenomenon and that Ab flexibility may also play a key role. We, moreover, saw that our Abs could enhance Fn binding in 3 out of 5 emm type strains tested, belonging to different clades, making it likely that this is a more generalizable phenomenon. Together our results suggest a novel synergistic interplay of GAS and host proteins which ultimately benefits the bacterium.
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9
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Ye J, Chen X. Current Promising Strategies against Antibiotic-Resistant Bacterial Infections. Antibiotics (Basel) 2022; 12:antibiotics12010067. [PMID: 36671268 PMCID: PMC9854991 DOI: 10.3390/antibiotics12010067] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 12/27/2022] [Accepted: 12/28/2022] [Indexed: 12/31/2022] Open
Abstract
Infections caused by antibiotic-resistant bacteria (ARB) are one of the major global health challenges of our time. In addition to developing new antibiotics to combat ARB, sensitizing ARB, or pursuing alternatives to existing antibiotics are promising options to counter antibiotic resistance. This review compiles the most promising anti-ARB strategies currently under development. These strategies include the following: (i) discovery of novel antibiotics by modification of existing antibiotics, screening of small-molecule libraries, or exploration of peculiar places; (ii) improvement in the efficacy of existing antibiotics through metabolic stimulation or by loading a novel, more efficient delivery systems; (iii) development of alternatives to conventional antibiotics such as bacteriophages and their encoded endolysins, anti-biofilm drugs, probiotics, nanomaterials, vaccines, and antibody therapies. Clinical or preclinical studies show that these treatments possess great potential against ARB. Some anti-ARB products are expected to become commercially available in the near future.
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10
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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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11
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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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12
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Classical complement pathway factor alterations in narcolepsy. Acta Neuropsychiatr 2022; 34:212-219. [PMID: 35034679 DOI: 10.1017/neu.2021.42] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Narcolepsy is a chronic sleep disorder long hypothesised to be an autoimmune disease. Complement-mediated immune mechanisms have not been investigated in detail in narcolepsy. Our aim was to establish the significance of classical pathway activation in narcolepsy. METHODS Sera of 42 narcolepsy patients and 26 healthy controls were screened with ELISA to determine the levels of C1q, C3a, C4d and complement component 4 binding protein (C4BP). A home-made ELISA method was developed to detect antibodies to C4BP-alpha (anti-C4BPA). The correlation between complement levels and clinical findings was examined. RESULTS C1q levels were significantly higher in narcolepsy patients while C4d and C4BP levels were significantly lower compared to healthy controls. C3a levels were comparable among patients and controls. Eleven narcolepsy patients showed serum anti-C4BPA levels. Total rapid eye movements (REM) time, sleep onset latency, REM sleep latency, sleep activity, percentage of wakefulness after sleep onset and Epworth sleepiness scale scores were correlated with levels of different complement factors. CONCLUSION Complement-mediated immune mechanisms might partake in narcolepsy pathogenesis. The precise role of autoantibodies on complement level alterations needs to be investigated. Levels of complement factors and degradation products may potentially be utilised as biomarkers to predict the clinical severity of narcolepsy.
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13
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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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14
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Akatsuka M, Masuda Y, Tatsumi H, Sonoda T. Efficacy of Intravenous Immunoglobulin Therapy for Patients With Sepsis and Low Immunoglobulin G Levels: A Single-Center Retrospective Study. Clin Ther 2022; 44:295-303. [PMID: 35000795 DOI: 10.1016/j.clinthera.2021.12.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 12/16/2021] [Accepted: 12/16/2021] [Indexed: 11/03/2022]
Abstract
PURPOSE The efficacy of intravenous immunoglobulin (IVIG) administration in patients with sepsis or septic shock remains unclear. A single-center retrospective study was conducted to evaluate the association between IVIG supplementation and favorable outcomes in patients with sepsis and low serum immunoglobulin G (IgG) levels. METHODS A total of 239 patients with sepsis were identified whose serum IgG levels were determined upon admission to the intensive care unit between January 2014 and March 2021. Patients with low IgG levels (<670 mg/dL) were divided into the IVIG and non-IVIG groups. Patient data were collected from electronic medical records to evaluate the patients' characteristics, sepsis severity, and prognosis. The primary outcome was 28-day mortality. The propensity score was calculated by using the following variables: age, Sequential Organ Failure Assessment score, immunocompromised status, and serum IgG levels. Logistic regression analysis using propensity score as the adjusted variable was performed to evaluate the outcome. FINDINGS Of 239 patients, 87 had low IgG levels. Of these patients, 47 received IVIG therapy. The 28-day (odds ratio [OR], 0.15; 95% CI, 0.04-0.54; P = 0.004) and 90-day (OR, 0.31; 95% CI, 0.11-0.83; P = 0.020) mortality rates were significantly lower in the IVIG group than in the non-IVIG group. Moreover, the number of days free from renal replacement therapy was significantly higher in the IVIG group than in the non-IVIG group (OR, 1.06; 95% CI, 1.01-1.11; P = 0.025). Serum IgG levels in the IVIG group showed no significant difference compared with those in the non-IVIG group. No significant differences in the patients' characteristics were observed between the groups. IMPLICATIONS This study found that IVIG administration in patients with sepsis and low serum IgG levels was associated with improved prognosis. Further studies are warranted to evaluate the validity of IVIG therapy for patients with sepsis and low serum IgG levels.
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Affiliation(s)
- Masayuki Akatsuka
- Department of Intensive Care Medicine, Sapporo Medical University School of Medicine, Sapporo, Hokkaido, Japan.
| | - Yoshiki Masuda
- Department of Intensive Care Medicine, Sapporo Medical University School of Medicine, Sapporo, Hokkaido, Japan
| | - Hiroomi Tatsumi
- Department of Intensive Care Medicine, Sapporo Medical University School of Medicine, Sapporo, Hokkaido, Japan
| | - Tomoko Sonoda
- Department of Public Health, Sapporo Medical University School of Medicine, Sapporo, Hokkaido, Japan
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15
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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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16
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Bläckberg A, de Neergaard T, Frick IM, Nordenfelt P, Lood R, Rasmussen M. Lack of Opsonic Antibody Responses to Invasive Infections With Streptococcus dysgalactiae. Front Microbiol 2021; 12:635591. [PMID: 33986732 PMCID: PMC8111088 DOI: 10.3389/fmicb.2021.635591] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 03/31/2021] [Indexed: 11/29/2022] Open
Abstract
Introduction Streptococcus dysgalactiae can cause severe recurrent infections. This study aimed to investigate antibody responses following S. dysgalactiae bacteraemia and possible development of protective immunity. Materials and Methods Patients with S. dysgalactiae bacteraemia in the county of Skåne between 2017 and 2018 were prospectively included. Acute and convalescent sera were obtained. All isolates were emm typed and enzyme-linked immunosorbent assay (ELISA) was utilised to analyse specific antibody responses to bacteria and antigens. Bactericidal- and phagocytosis assays were applied to further establish antibody function. Results Sixteen patients with S. dysgalactiae bacteraemia were included of whom one had recurrent episodes of bacteraemia. Using ELISA with S. dysgalactiae isolates and mutants, development of IgG antibodies was demonstrated in few patients. Type-specific antibodies were demonstrated in one patient when recombinant M proteins as antigens, were applied. The type-specific serum mediated a small increase in phagocytosis but did not facilitate increased killing of the S. dysgalactiae isolate, carrying that M protein, in blood or by phagocytic cells. Conclusion S. dysgalactiae bacteraemia sometimes results in increased levels of antibodies to the infecting pathogen. We did not find evidence that these antibodies are effectively opsonising. Apparent failure to produce opsonising antibodies might partially explain why S. dysgalactiae can cause recurrent invasive infections in the same host.
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Affiliation(s)
- Anna Bläckberg
- Division of Infection Medicine, Department of Clinical Sciences Lund, Lund University, Lund, Sweden.,Skåne University Hospital, Department of Infectious Diseases, Lund, Sweden
| | - Therese de Neergaard
- Division of Infection Medicine, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
| | - Inga-Maria Frick
- Division of Infection Medicine, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
| | - Pontus Nordenfelt
- Division of Infection Medicine, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
| | - Rolf Lood
- Division of Infection Medicine, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
| | - Magnus Rasmussen
- Division of Infection Medicine, Department of Clinical Sciences Lund, Lund University, Lund, Sweden.,Skåne University Hospital, Department of Infectious Diseases, Lund, Sweden
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17
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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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18
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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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19
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Structural determination of Streptococcus pyogenes M1 protein interactions with human immunoglobulin G using integrative structural biology. PLoS Comput Biol 2021; 17:e1008169. [PMID: 33411763 PMCID: PMC7817036 DOI: 10.1371/journal.pcbi.1008169] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 01/20/2021] [Accepted: 11/24/2020] [Indexed: 01/31/2023] Open
Abstract
Streptococcus pyogenes (Group A streptococcus; GAS) is an important human pathogen responsible for mild to severe, life-threatening infections. GAS expresses a wide range of virulence factors, including the M family proteins. The M proteins allow the bacteria to evade parts of the human immune defenses by triggering the formation of a dense coat of plasma proteins surrounding the bacteria, including IgGs. However, the molecular level details of the M1-IgG interaction have remained unclear. Here, we characterized the structure and dynamics of this interaction interface in human plasma on the surface of live bacteria using integrative structural biology, combining cross-linking mass spectrometry and molecular dynamics (MD) simulations. We show that the primary interaction is formed between the S-domain of M1 and the conserved IgG Fc-domain. In addition, we show evidence for a so far uncharacterized interaction between the A-domain and the IgG Fc-domain. Both these interactions mimic the protein G-IgG interface of group C and G streptococcus. These findings underline a conserved scavenging mechanism used by GAS surface proteins that block the IgG-receptor (FcγR) to inhibit phagocytic killing. We additionally show that we can capture Fab-bound IgGs in a complex background and identify XLs between the constant region of the Fab-domain and certain regions of the M1 protein engaged in the Fab-mediated binding. Our results elucidate the M1-IgG interaction network involved in inhibition of phagocytosis and reveal important M1 peptides that can be further investigated as future vaccine targets. Streptococcus pyogenes is a human specific pathogen causing both mild and invasive infections. It employs sophisticated mechanisms to evade and circumvent parts of the host’s immune defenses, in part via its major surface associated virulence factor, the family of M proteins. Of these, the M1 protein is the most prevalent serotype. The M1 protein creates a dense coat-like structure with multiple host proteins on the bacterial surface to disguise itself from opsonizing antibodies. It specifically interacts in a non-immune way with human immunoglobulin G (IgG) Fc-domains to disarm their receptor binding site. The molecular level details of this interaction have not been characterized. Here, we describe these interactions from minimally perturbed samples of human plasma adsorbed onto living bacteria using an integrative structural biology approach including cross-linking mass spectrometry, molecular modeling, and molecular dynamics simulations. We identify two distinct M1-peptides that bind IgGs and reveal the stability of these interactions. We show that both peptides block the Fc-receptor binding sites through capturing IgGs via their Fc-domains. These results highlight the importance of describing novel pathogen-derived peptides mediating host immune evasion as potential vaccine targets in future studies.
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20
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de Neergaard T, Sundwall M, Wrighton S, Nordenfelt P. High-Sensitivity Assessment of Phagocytosis by Persistent Association-Based Normalization. THE JOURNAL OF IMMUNOLOGY 2020; 206:214-224. [PMID: 33268484 DOI: 10.4049/jimmunol.2000032] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 10/29/2020] [Indexed: 01/04/2023]
Abstract
Phagocytosis is measured as a functional outcome in many research fields, but accurate quantification can be challenging, with no robust method available for cross-laboratory reproducibility. In this study, we identified a simple, measurable parameter, persistent prey-phagocyte association, to use for normalization and dose-response analysis. We apply this in a straightforward analytical method, persistent association-based normalization, in which the multiplicity of prey (MOP) ratio needed to elicit half of the phagocytes to associate persistently (MOP50) is determined first. MOP50 is then applied to normalize for experimental factors, separately analyzing association and internalization. We use reference human phagocyte THP-1 cells with different prey and opsonization conditions to compare the persistent association-based normalization method to standard ways of assessing phagocytosis and find it to perform better, exhibiting increased robustness, sensitivity, and reproducibility. The approach is easily incorporated into most existing phagocytosis assays and allows for reproducible results with high sensitivity.
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Affiliation(s)
- Therese de Neergaard
- Division of Infection Medicine, Department of Clinical Sciences, Faculty of Medicine, Lund University, 221 84 Lund, Sweden
| | - Martin Sundwall
- Division of Infection Medicine, Department of Clinical Sciences, Faculty of Medicine, Lund University, 221 84 Lund, Sweden
| | - Sebastian Wrighton
- Division of Infection Medicine, Department of Clinical Sciences, Faculty of Medicine, Lund University, 221 84 Lund, Sweden
| | - Pontus Nordenfelt
- Division of Infection Medicine, Department of Clinical Sciences, Faculty of Medicine, Lund University, 221 84 Lund, Sweden
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21
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Li M, Wang H, Li W, Xu XG, Yu Y. Macrophage activation on "phagocytic synapse" arrays: Spacing of nanoclustered ligands directs TLR1/2 signaling with an intrinsic limit. SCIENCE ADVANCES 2020; 6:6/49/eabc8482. [PMID: 33268354 PMCID: PMC7821875 DOI: 10.1126/sciadv.abc8482] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Accepted: 10/19/2020] [Indexed: 05/02/2023]
Abstract
The activation of Toll-like receptor heterodimer 1/2 (TLR1/2) by microbial components plays a critical role in host immune responses against pathogens. TLR1/2 signaling is sensitive to the chemical structure of ligands, but its dependence on the spatial distribution of ligands on microbial surfaces remains unexplored. Here, we reveal the quantitative relationship between TLR1/2-triggered immune responses and the spacing of ligand clusters by designing an artificial "phagocytic synapse" nanoarray platform to mimic the cell-microbe interface. The ligand spacing dictates the proximity of receptor clusters on the cell surface and consequently the pro-inflammatory responses of macrophages. However, cell responses reach their maximum at small ligand spacings when the receptor nanoclusters become adjacent to one another. Our study demonstrates the feasibility of using spatially patterned ligands to modulate innate immunity. It shows that the receptor clusters of TLR1/2 act as a driver in integrating the spatial cues of ligands into cell-level activation events.
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Affiliation(s)
- Miao Li
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA
| | - Haomin Wang
- Department of Chemistry, Lehigh University, Bethlehem, PA 18015, USA
| | - Wenqian Li
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA
| | - Xiaoji G Xu
- Department of Chemistry, Lehigh University, Bethlehem, PA 18015, USA
| | - Yan Yu
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA.
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22
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Sukumaran A, Woroszchuk E, Ross T, Geddes-McAlister J. Proteomics of host-bacterial interactions: new insights from dual perspectives. Can J Microbiol 2020; 67:213-225. [PMID: 33027598 DOI: 10.1139/cjm-2020-0324] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Mass-spectrometry (MS)-based proteomics is a powerful and robust platform for studying the interactions between biological systems during health and disease. Bacterial infections represent a significant threat to global health and drive the pursuit of novel therapeutic strategies to combat emerging and resistant pathogens. During infection, the interplay between a host and pathogen determines the ability of the microbe to survive in a hostile environment and promotes an immune response by the host as a protective measure. It is the protein-level changes from either biological system that define the outcome of infection, and MS-based proteomics provides a rapid and effective platform to identify such changes. In particular, proteomics detects alterations in protein abundance, quantifies protein secretion and (or) release, measures an array of post-translational modifications that influence signaling cascades, and profiles protein-protein interactions through protein complex and (or) network formation. Such information provides new insight into the role of known and novel bacterial effectors, as well as the outcome of host cell activation. In this Review, we highlight the diverse applications of MS-based proteomics in profiling the relationship between bacterial pathogens and the host. Our work identifies a plethora of strategies for exploring mechanisms of infection from dual perspectives (i.e., host and pathogen), and we suggest opportunities to extrapolate the current knowledgebase to other biological systems for applications in therapeutic discovery.
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Affiliation(s)
- Arjun Sukumaran
- Molecular and Cellular Biology Department, University of Guelph, Guelph, ON N1G 2W1, Canada.,Molecular and Cellular Biology Department, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Elizabeth Woroszchuk
- Molecular and Cellular Biology Department, University of Guelph, Guelph, ON N1G 2W1, Canada.,Molecular and Cellular Biology Department, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Taylor Ross
- Molecular and Cellular Biology Department, University of Guelph, Guelph, ON N1G 2W1, Canada.,Molecular and Cellular Biology Department, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Jennifer Geddes-McAlister
- Molecular and Cellular Biology Department, University of Guelph, Guelph, ON N1G 2W1, Canada.,Molecular and Cellular Biology Department, University of Guelph, Guelph, ON N1G 2W1, Canada
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The first report on immunoglobulins A, E, G and M levels in cystic fibrosis patients in Saudi Arabia. Saudi J Biol Sci 2020; 27:2617-2621. [PMID: 32994719 PMCID: PMC7499114 DOI: 10.1016/j.sjbs.2020.05.041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 05/22/2020] [Accepted: 05/23/2020] [Indexed: 12/22/2022] Open
Abstract
Background Previous reports have shown that pulmonary and systemic hypergamma-globulinemia in CF patients is a reflection of chronic pulmonary infection. Infection with Pseudomonas aeruginosa is known to have major prognostic significance in patients CF. This study aims to identify the incidence of immunoglobulins (especially: IgG, and IgE) in a cohort of CF patients. Methods A total of 297 patients recruited all over the country’s region for this study were a as part of the CF registry data from 1st January 1984 to 1st June 2016. All patients had their immunoglobulin levels measured by enzyme link immunosorbent assay (ELISA) in 3 stages, at presentation and two follow-ups. Results Of the 297 patients recruited, 139 (46.8%) were males while 158 (53.2%) were females. IgA and IgM levels were found not to have risen above the previously reported levels in healthy individuals in all stages. On the contrary, IgE level increased from 209.51 ± 32.30 KU/L to 303.58 ± 37.11 KU/L from baseline to stage 3 while IgG level rose from 12.26 ± 0.43 mg/mL to 17.17 ± 1.68 mg/mL for baseline and stage 3 respectively all above previously reported levels in healthy individuals. Conclusion This study establishes a potential for the use of IgE and IgG in disease diagnosis as well as the prognostic implications. However, further study is needed to identify the role of infection or medications in relation to the rise of both IgE and IgG with advancement of age and progression of disease severity which may inherently confound the observed results.
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Sharma S, Subramani S, Popa I. Does protein unfolding play a functional role in vivo? FEBS J 2020; 288:1742-1758. [PMID: 32761965 DOI: 10.1111/febs.15508] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 07/09/2020] [Accepted: 08/03/2020] [Indexed: 12/21/2022]
Abstract
Unfolding and refolding of multidomain proteins under force have yet to be recognized as a major mechanism of function for proteins in vivo. In this review, we discuss the inherent properties of multidomain proteins under a force vector from a structural and functional perspective. We then characterize three main systems where multidomain proteins could play major roles through mechanical unfolding: muscular contraction, cellular mechanotransduction, and bacterial adhesion. We analyze how key multidomain proteins for each system can produce a gain-of-function from the perspective of a fine-tuned quantized response, a molecular battery, delivery of mechanical work through refolding, elasticity tuning, protection and exposure of cryptic sites, and binding-induced mechanical changes. Understanding how mechanical unfolding and refolding affect function will have important implications in designing mechano-active drugs against conditions such as muscular dystrophy, cancer, or novel antibiotics.
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Affiliation(s)
- Sabita Sharma
- Department of Physics, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - Smrithika Subramani
- Department of Physics, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - Ionel Popa
- Department of Physics, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
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25
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Delamare-Deboutteville J, Kawasaki M, Zoccola E, Heath CM, Bowater RO, Barnes AC. Interactions of head-kidney leucocytes from giant grouper, Epinephelus lanceolatus, with pathogenic Streptococcus agalactiae strains from marine and terrestrial origins. FISH & SHELLFISH IMMUNOLOGY 2019; 90:250-263. [PMID: 31026501 DOI: 10.1016/j.fsi.2019.04.058] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 04/17/2019] [Accepted: 04/22/2019] [Indexed: 06/09/2023]
Abstract
Streptococcus agalactiae (Group B Streptococcus, GBS) is emerging as a genetically diverse species infecting farmed and wild fish, including commercially and culturally important groupers. To better understand how S. agalactiae are pathogenic in fish, we investigated interactions between isolates from fish and terrestrial hosts and the cellular immune system of Queensland grouper Epinephelus lanceolatus using flow cytometry. Adherent head-kidney leucocytes (HKL) from Queensland grouper displayed two main cell populations with distinct forward and side scatter by flow cytometry. The population of smaller and less complex cells (P1) was composed of monocytes, lymphocytes and thrombocytes, while the population of primarily larger and more complex cells (P2) comprised predominantly of macrophages and neutrophils. The cells in P2 had higher phagocytic index and capacity when incubated with fluorescent latex beads. HKL were activated by phorbol myristate acetate (PMA) but were unresponsive to lipopolysaccharide (LPS) and peptidoglycan (PTG), suggesting the absence of specific receptors on the surface of these cells for these ligands or a requirement for intermediates. In in vitro phagocytosis assays, all fish isolates of GBS activated a respiratory burst in P2 indicated by significant production of intracellular reactive oxygen species (ROS). Similarly, dog and cat isolates of different serotype and sequence type also induced ROS production in grouper HKL. However, human, crocodile and bovine isolates of GBS did not elicit significant ROS in HKL although they coincided with the highest phagocytic index. This suggests that these strains are capable of quenching ROS production. Terrestrial isolates significantly increased mortality of Queensland grouper leucocytes in vitro, aligned with a more diverse repertoire of cellular toxins in these strains. Opsonisation of a marine strain and terrestrial strain of GBS with antiserum raised against the marine strain resulted in an increase in ROS production by HKL in both cases although there was low antigenic cross reactivity between the two strains by flow cytometry, reflecting their diverse serotypes (Ib vs III). However, pre-incubation of either strain with normal serum from grouper also increased ROS production of HKL suggesting other opsonins may be involved. Based on these results it appears that piscine and terrestrial GBS isolates have contrasting strategies when interacting with the cellular immune system of Queensland grouper; the former seemingly evading phagocytosis, whilst the latter are readily phagocytosed but counteract ROS production.
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Affiliation(s)
- Jérôme Delamare-Deboutteville
- The University of Queensland, School of Biological Sciences and Centre for Marine Science, Brisbane, Queensland, 4072, Australia
| | - Minami Kawasaki
- The University of Queensland, School of Biological Sciences and Centre for Marine Science, Brisbane, Queensland, 4072, Australia
| | - Emmanuelle Zoccola
- The University of Queensland, School of Biological Sciences and Centre for Marine Science, Brisbane, Queensland, 4072, Australia
| | - Candice M Heath
- The University of Queensland, School of Biological Sciences and Centre for Marine Science, Brisbane, Queensland, 4072, Australia
| | - Rachel O Bowater
- Biosecurity Queensland (North Region), Department of Agriculture and Fisheries, Townsville, Queensland, Australia
| | - Andrew C Barnes
- The University of Queensland, School of Biological Sciences and Centre for Marine Science, Brisbane, Queensland, 4072, Australia.
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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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27
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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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Brignoli T, Manetti AGO, Rosini R, Haag AF, Scarlato V, Bagnoli F, Delany I. Absence of Protein A Expression Is Associated With Higher Capsule Production in Staphylococcal Isolates. Front Microbiol 2019; 10:863. [PMID: 31133995 PMCID: PMC6523524 DOI: 10.3389/fmicb.2019.00863] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 04/04/2019] [Indexed: 12/19/2022] Open
Abstract
Staphylococcus aureus is a major human pathogen, and a leading cause of soft tissue and blood stream infections. One of the causes of its success as a pathogen is the peculiar array of immune evasion factors through which the bacterium avoids host defenses, where the staphylococcal protein A (SpA) plays a major role thanks to its IgG binding activities. Moreover, SpA has recently been proposed as a promising vaccine antigen. In this study, we evaluated the expression of SpA in a collection of staphylococcal strains, about 7% of which did not express SpA (SpA- strains), despite the presence of the gene. By a comparative genomic analysis, we identified that a mutation in the spa 5′ UTR sequence affecting the RBS is responsible for the loss of SpA in a subset of SpA- strains. Using a high-throughput qRT-PCR approach on a selected panel of virulence-related genes, we identified that the SpA- phenotype is associated with lower spa transcript levels and increased expression and production of capsule as well as other changes in the transcription of several key virulence factors. Our data suggest that the SpA- phenotype has occurred in geographically distinct strains through different molecular mechanisms including both mutation, leading likely to translation alterations, and transcriptional deregulation. Furthermore, we provide evidence that SpA- strains are highly susceptible to phagocytic uptake mediated by anti-capsule antibodies. These data suggest that S. aureus may alter its virulence factor expression pattern as an adaptation to the host or environment. Vaccination strategies targeting both SpA and capsule could therefore result in broader coverage against staphylococcal isolates than SpA alone.
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Affiliation(s)
- Tarcisio Brignoli
- GSK Vaccines, Siena, Italy.,Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, Bologna, Italy
| | | | | | - Andreas F Haag
- GSK Vaccines, Siena, Italy.,Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Vincenzo Scarlato
- Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, Bologna, Italy
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Rungelrath V, Weiße C, Schütze N, Müller U, Meurer M, Rohde M, Seele J, Valentin-Weigand P, Kirschfink M, Beineke A, Schrödl W, Bergmann R, Baums CG. IgM cleavage by Streptococcus suis reduces IgM bound to the bacterial surface and is a novel complement evasion mechanism. Virulence 2019; 9:1314-1337. [PMID: 30001174 PMCID: PMC6177247 DOI: 10.1080/21505594.2018.1496778] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Streptococcus suis (S. suis) causes meningitis, arthritis and endocarditis in piglets. The aim of this study was to characterize the IgM degrading enzyme of S. suis (IdeSsuis) and to investigate the role of IgM cleavage in evasion of the classical complement pathway and pathogenesis. Targeted mutagenesis of a cysteine in the putative active center of IdeSsuis abrogated IgM cleavage completely. In contrast to wt rIdeSsuis, point mutated rIdeSsuis_C195S did not reduce complement-mediated hemolysis indicating that complement inhibition by rIdeSsuis depends on the IgM proteolytic activity. A S. suis mutant expressing IdeSsuis_C195S did not reduce IgM labeling, whereas the wt and complemented mutant showed less IgM F(ab’)2 and IgM Fc antigen on the surface. IgM cleavage increased survival of S. suis in porcine blood ex vivo and mediated complement evasion as demonstrated by blood survival and C3 deposition assays including the comparative addition of rIdeSsuis and rIdeSsuis_C195S. However, experimental infection of piglets disclosed no significant differences in virulence between S. suis wt and isogenic mutants without IgM cleavage activity. This work revealed for the first time in vivo labeling of S. suis with IgM in the cerebrospinal fluid of piglets with meningitis. In conclusion, this study classifies IdeSsuis as a cysteine protease and emphasizes the role of IgM cleavage for bacterial survival in porcine blood and complement evasion though IgM cleavage is not crucial for the pathogenesis of serotype 2 meningitis.
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Affiliation(s)
- Viktoria Rungelrath
- a Institute for Bacteriology and Mycology, Centre for Infectious Diseases, Veterinary Faculty , University of Leipzig , Leipzig , Germany
| | - Christine Weiße
- a Institute for Bacteriology and Mycology, Centre for Infectious Diseases, Veterinary Faculty , University of Leipzig , Leipzig , Germany
| | - Nicole Schütze
- b Institute of Immunology, Centre for Infectious Diseases, Veterinary Faculty , University of Leipzig , Leipzig , Germany
| | - Uwe Müller
- b Institute of Immunology, Centre for Infectious Diseases, Veterinary Faculty , University of Leipzig , Leipzig , Germany
| | - Marita Meurer
- c Department of Physiological Chemistry and Research Center for Emerging Infections and Zoonoses (RIZ) , University of Veterinary Medicine Hannover , Hannover , Germany
| | - Manfred Rohde
- d Central Facility for Microscopy , Helmholtz Centre for Infection Research , Braunschweig , Germany
| | - Jana Seele
- e Department of Neuropathology , University Medical Center Göttingen, Georg-August-University Göttingen , Göttingen , Germany.,f Department of Geriatrics , Evangelisches Krankenhaus Göttingen-Weende , Göttingen , Germany
| | - Peter Valentin-Weigand
- g Institute for Microbiology, Centre for Infection Medicine , University of Veterinary Medicine Hannover , Hanover , Germany
| | - Michael Kirschfink
- h Institute of Immunology , University of Heidelberg , Heidelberg , Germany
| | - Andreas Beineke
- i Department of Pathology , University of Veterinary Medicine Hannover , Hannover , Germany
| | - Wieland Schrödl
- a Institute for Bacteriology and Mycology, Centre for Infectious Diseases, Veterinary Faculty , University of Leipzig , Leipzig , Germany
| | - René Bergmann
- a Institute for Bacteriology and Mycology, Centre for Infectious Diseases, Veterinary Faculty , University of Leipzig , Leipzig , Germany
| | - Christoph Georg Baums
- a Institute for Bacteriology and Mycology, Centre for Infectious Diseases, Veterinary Faculty , University of Leipzig , Leipzig , Germany
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30
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Vadamalai K, Sanche-Tejera D, Bress J, Mustafa SS. Screening for Humoral Immunodeficiency in Patients with Community-Acquired Pneumonia. J Hosp Med 2019; 14:33037. [PMID: 30534641 DOI: 10.12788/jhm.3106] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Immunodeficiency is an underrecognized risk factor for infections, such as community-acquired pneumonia (CAP). OBJECTIVE We evaluated patients admitted with CAP for humoral immunodeficiency. DESIGN Prospective Cohort Study. SETTING Inpatients. PATIENTS, INTERVENTION, AND MEASUREMENTS We enrolled 100 consecutive patients admitted with a diagnosis of CAP from February 2017 to April 2017. Serum IgG, IgM, IgA, and IgE levels were obtained within the first 24 hours of admission. CURB-65 score and length of hospital stay were calculated. The Wilcoxon rank-sum test, Kruskal-Wallis test, and simple linear regression analysis were used in data analysis. RESULTS The prevalence of hypogammaglobinemia in patients with CAP was 38% (95% confidence interval: 28.47% to 48.25%). Twenty-seven of 100 patients had IgG hypogammaglobinemia (median: 598 mg/dL, IQ range: 459-654), 23 of 100 had IgM hypogammaglobinemia (median: 38 mg/dL, IQ range: 25-43), and 6 of 100 had IgA hypogammaglobinemia (median: 36 mg/dL, IQ range: 18-50). The median hospital length of stay for patients with IgG hypogammaglobinemia was significantly higher when compared to patients with normal IgG levels (five days, IQ range [3-10] vs three days, IQ range [2-5], P = .0085). Fourteen patients underwent further immune evaluation, resulting in one diagnosis of multiple myeloma, three patients diagnosed with specific antibody deficiency, and one patient diagnosed with selective IgA deficiency. CONCLUSION There is a high prevalence of hypogammaglobinemia in patients hospitalized with CAP, with IgG and IgM being the most commonly affected classes. IgG hypogammaglobinemia was associated with an increased length of hospitalization. Screening immunoglobulin levels in CAP patients may also uncover underlying humoral immunodeficiency or immunoproliferative disorders.
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Affiliation(s)
| | | | - Jonathan Bress
- Rochester Regional Health, Rochester, New York, USA
- Rochester Institute of Technology, Rochester, New York, USA
| | - S Shahzad Mustafa
- Rochester Regional Health, Rochester, New York, USA
- University of Rochester School of Medicine and Dentistry, Rochester, New York, USA.
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31
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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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Lysostaphin Lysibody Leads to Effective Opsonization and Killing of Methicillin-Resistant Staphylococcus aureus in a Murine Model. Antimicrob Agents Chemother 2018; 62:AAC.01056-18. [PMID: 30038041 DOI: 10.1128/aac.01056-18] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 07/16/2018] [Indexed: 12/31/2022] Open
Abstract
The cell wall of Gram-positive bacteria contains abundant surface-exposed carbohydrate structures that are highly conserved. While these properties make surface carbohydrates ideal targets for immunotherapy, carbohydrates elicit a poor immune response that results primarily in low-affinity IgM antibodies. In a previous publication, we introduced the lysibody approach to address this shortcoming. Lysibodies are engineered molecules that combine a high-affinity carbohydrate-binding domain of bacterial or bacteriophage origin and an Fc effector portion of a human IgG antibody, thus directing effective immunity to conserved bacterial surface carbohydrates. Here, we describe the first example of a lysibody containing the binding domain from a bacteriocin, lysostaphin. We also describe the creation of five lysibodies with binding domains derived from phage lysins, directed against Staphylococcus aureus The lysostaphin and LysK lysibodies showed the most promise and were further characterized. Both lysibodies bound a range of clinically important staphylococcal strains, fixed complement on the staphylococcal surface, and induced phagocytosis of S. aureus by macrophages and human neutrophils. The lysostaphin lysibody had superior in vitro activity compared to that of the LysK lysibody, as well as that of the previously characterized ClyS lysibody, and it effectively protected mice in a kidney abscess/bacteremia model. These results further demonstrate that the lysibody approach is a reproducible means of creating antibacterial antibodies that cannot be produced by conventional means. Lysibodies therefore are a promising solution for opsonic antibodies that may be used passively to both treat and prevent infection by drug-resistant pathogens.
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Hurtado R, Carhuaricra D, Soares S, Viana MVC, Azevedo V, Maturrano L, Aburjaile F. Pan-genomic approach shows insight of genetic divergence and pathogenic-adaptation of Pasteurella multocida. Gene 2018; 670:193-206. [PMID: 29802996 DOI: 10.1016/j.gene.2018.05.084] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 05/06/2018] [Accepted: 05/21/2018] [Indexed: 10/16/2022]
Abstract
Pasteurella multocida is a gram-negative, non-motile bacterial pathogen, which is associated with chronic and acute infections as snuffles, pneumonia, atrophic rhinitis, fowl cholera and hemorrhagic septicemia. These diseases affect a wide range of domestic animals, leading to significant morbidity and mortality and causing significant economic losses worldwide. Due to the interest in deciphering the genetic diversity and process adaptive between P. multocida strains, this work aimed was to perform a pan-genome analysis to evidence horizontal gene transfer and positive selection among 23 P. multocida strains isolated from distinct diseases and hosts. The results revealed an open pan-genome containing 3585 genes and an accessory genome presenting 1200 genes. The phylogenomic analysis based on the presence/absence of genes and islands exhibit high levels of plasticity, which reflects a high intraspecific diversity and a possible adaptive mechanism responsible for the specific disease manifestation between the established groups (pneumonia, fowl cholera, hemorrhagic septicemia and snuffles). Additionally, we identified differences in accessory genes among groups, which are involved in sugar metabolism and transport systems, virulence-related genes and a high concentration of hypothetical proteins. However, there was no specific indispensable functional mechanism to decisively correlate the presence of genes and their adaptation to a specific host/disease. Also, positive selection was found only for two genes from sub-group hemorrhagic septicemia, serotype B. This comprehensive comparative genome analysis will provide new insights of horizontal gene transfers that play an essential role in the diversification and adaptation mechanism into P. multocida species to a specific disease.
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Affiliation(s)
- Raquel Hurtado
- Laboratory of Cellular and Molecular Genetics, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Dennis Carhuaricra
- Laboratory of Molecular Biology and Genetics, Veterinary Medicine Faculty, San Marcos University, Lima, Peru
| | - Siomar Soares
- Department of Microbiology, Immunology and Parasitology, Institute of Biological and Natural Sciences, Federal University of Triângulo Mineiro, Uberaba, Minas Gerais, Brazil
| | - Marcus Vinicius Canário Viana
- Laboratory of Cellular and Molecular Genetics, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Vasco Azevedo
- Laboratory of Cellular and Molecular Genetics, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Lenin Maturrano
- Laboratory of Molecular Biology and Genetics, Veterinary Medicine Faculty, San Marcos University, Lima, Peru
| | - Flávia Aburjaile
- Laboratory of Cellular and Molecular Genetics, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil; Laboratory of Plant Genetics and Biotechnology, Federal University of Pernambuco, Recife, Pernambuco, Brazil.
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34
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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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35
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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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36
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Huseyin CE, O'Toole PW, Cotter PD, Scanlan PD. Forgotten fungi-the gut mycobiome in human health and disease. FEMS Microbiol Rev 2017; 41:479-511. [PMID: 28430946 DOI: 10.1093/femsre/fuw047] [Citation(s) in RCA: 154] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 01/04/2017] [Indexed: 12/11/2022] Open
Abstract
The human body is home to a complex and diverse microbial ecosystem that plays a central role in host health. This includes a diversity of fungal species that is collectively referred to as our 'mycobiome'. Although research into the mycobiome is still in its infancy, its potential role in human disease is increasingly recognised. Here we review the existing literature available on the human mycobiota with an emphasis on the gut mycobiome, including how fungi interact with the human host and other microbes. In doing so, we provide a comprehensive critique of the methodologies available to research the human mycobiota as well as highlighting the latest research findings from mycological surveys of different groups of interest including infants, obese and inflammatory bowel disease cohorts. This in turn provides new insights and directions for future studies in this burgeoning research area.
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Affiliation(s)
- Chloe E Huseyin
- Teagasc Food Research Centre, Moorepark, Fermoy, Cork P61 C996, Ireland.,APC Microbiome Institute, Biosciences Institute, University College Cork, Cork T12 YT20 Ireland.,School of Microbiology, University College Cork, Cork T12 YT20, Ireland
| | - Paul W O'Toole
- APC Microbiome Institute, Biosciences Institute, University College Cork, Cork T12 YT20 Ireland.,School of Microbiology, University College Cork, Cork T12 YT20, Ireland
| | - Paul D Cotter
- Teagasc Food Research Centre, Moorepark, Fermoy, Cork P61 C996, Ireland.,APC Microbiome Institute, Biosciences Institute, University College Cork, Cork T12 YT20 Ireland
| | - Pauline D Scanlan
- APC Microbiome Institute, Biosciences Institute, University College Cork, Cork T12 YT20 Ireland
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37
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Öster C, Kosol S, Hartlmüller C, Lamley JM, Iuga D, Oss A, Org ML, Vanatalu K, Samoson A, Madl T, Lewandowski JR. Characterization of Protein-Protein Interfaces in Large Complexes by Solid-State NMR Solvent Paramagnetic Relaxation Enhancements. J Am Chem Soc 2017; 139:12165-12174. [PMID: 28780861 PMCID: PMC5590091 DOI: 10.1021/jacs.7b03875] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
Solid-state NMR is becoming a viable
alternative for obtaining
information about structures and dynamics of large biomolecular complexes,
including ones that are not accessible to other high-resolution biophysical
techniques. In this context, methods for probing protein–protein
interfaces at atomic resolution are highly desirable. Solvent paramagnetic
relaxation enhancements (sPREs) proved to be a powerful method for
probing protein–protein interfaces in large complexes in solution
but have not been employed toward this goal in the solid state. We
demonstrate that 1H and 15N relaxation-based
sPREs provide a powerful tool for characterizing intermolecular interactions
in large assemblies in the solid state. We present approaches for
measuring sPREs in practically the entire range of magic angle spinning
frequencies used for biomolecular studies and discuss their benefits
and limitations. We validate the approach on crystalline GB1, with
our experimental results in good agreement with theoretical predictions.
Finally, we use sPREs to characterize protein–protein interfaces
in the GB1 complex with immunoglobulin G (IgG). Our results suggest
the potential existence of an additional binding site and provide
new insights into GB1:IgG complex structure that amend and revise
the current model available from studies with IgG fragments. We demonstrate
sPREs as a practical, widely applicable, robust, and very sensitive
technique for determining intermolecular interaction interfaces in
large biomolecular complexes in the solid state.
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Affiliation(s)
- Carl Öster
- Department of Chemistry, University of Warwick , Gibbet Hill Road, Coventry CV4 7AL, U.K
| | - Simone Kosol
- Department of Chemistry, University of Warwick , Gibbet Hill Road, Coventry CV4 7AL, U.K
| | - Christoph Hartlmüller
- Center for Integrated Protein Science, Department of Chemistry, Munich Technische Universität München , Lichtenbergstrasse 4, 85748 Garching, Germany.,Institute of Structural Biology, Helmholtz Zentrum München , Ingolstädter Landstrasse 1, 85764 Neuherberg, Germany
| | - Jonathan M Lamley
- Department of Chemistry, University of Warwick , Gibbet Hill Road, Coventry CV4 7AL, U.K
| | - Dinu Iuga
- Department of Physics, University of Warwick , Gibbet Hill Road, Coventry CV4 7AL, U.K
| | - Andres Oss
- Institute of Health Technologies, Tallinn University of Technology , Akadeemia tee 15a, 19086 Tallinn, Estonia
| | - Mai-Liis Org
- Institute of Health Technologies, Tallinn University of Technology , Akadeemia tee 15a, 19086 Tallinn, Estonia
| | - Kalju Vanatalu
- Institute of Health Technologies, Tallinn University of Technology , Akadeemia tee 15a, 19086 Tallinn, Estonia
| | - Ago Samoson
- Institute of Health Technologies, Tallinn University of Technology , Akadeemia tee 15a, 19086 Tallinn, Estonia
| | - Tobias Madl
- Center for Integrated Protein Science, Department of Chemistry, Munich Technische Universität München , Lichtenbergstrasse 4, 85748 Garching, Germany.,Institute of Structural Biology, Helmholtz Zentrum München , Ingolstädter Landstrasse 1, 85764 Neuherberg, Germany.,Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz , Harrachgasse 21, 8010 Graz, Austria
| | - Józef R Lewandowski
- Department of Chemistry, University of Warwick , Gibbet Hill Road, Coventry CV4 7AL, U.K
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38
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Lysibodies are IgG Fc fusions with lysin binding domains targeting Staphylococcus aureus wall carbohydrates for effective phagocytosis. Proc Natl Acad Sci U S A 2017; 114:4781-4786. [PMID: 28428342 DOI: 10.1073/pnas.1619249114] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The cell wall of Gram-positive bacteria contains abundant surface-exposed carbohydrate molecules that are highly conserved within and often across species. The potential therapeutic usefulness of high-affinity antibodies to cell wall carbohydrates is unquestioned, however obtaining such antibodies is challenging due to the poor overall immunogenicity of these bacterial targets. Autolysins and phage lysins are peptidoglycan hydrolases, enzymes that have evolved over a billion years to degrade bacterial cell wall. Such wall hydrolases are modular enzymes, composed of discrete domains for high-affinity binding to cell wall carbohydrates and cleavage activity. In this study, we demonstrate that binding domains from autolysins and lysins can be fused to the Fc region of human IgG, creating a fully functional homodimer (or "lysibody") with high-affinity binding and specificity for carbohydrate determinants on the bacterial surface. Furthermore, we demonstrate that this process is reproducible with three different binding domains specific to methicillin-resistant Staphylococcus aureus (MRSA). Cell-bound lysibodies induced the fixation of complement on the bacterial surface, promoted phagocytosis by macrophages and neutrophils, and protected mice from MRSA infection in two model systems. The lysibody approach could be used to target a range of difficult-to-treat pathogenic bacteria, given that cell wall hydrolases are ubiquitous in nature.
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39
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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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40
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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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41
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Swe PM, Christian LD, Lu HC, Sriprakash KS, Fischer K. Complement inhibition by Sarcoptes scabiei protects Streptococcus pyogenes - An in vitro study to unravel the molecular mechanisms behind the poorly understood predilection of S. pyogenes to infect mite-induced skin lesions. PLoS Negl Trop Dis 2017; 11:e0005437. [PMID: 28278252 PMCID: PMC5360341 DOI: 10.1371/journal.pntd.0005437] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 03/21/2017] [Accepted: 02/25/2017] [Indexed: 02/01/2023] Open
Abstract
Background On a global scale scabies is one of the most common dermatological conditions, imposing a considerable economic burden on individuals, communities and health systems. There is substantial epidemiological evidence that in tropical regions scabies is often causing pyoderma and subsequently serious illness due to invasion by opportunistic bacteria. The health burden due to complicated scabies causing cellulitis, bacteraemia and sepsis, heart and kidney diseases in resource-poor communities is extreme. Co-infections of group A streptococcus (GAS) and scabies mites is a common phenomenon in the tropics. Both pathogens produce multiple complement inhibitors to overcome the host innate defence. We investigated the relative role of classical (CP), lectin (LP) and alternative pathways (AP) towards a pyodermic GAS isolate 88/30 in the presence of a scabies mite complement inhibitor, SMSB4. Methodology/Principal findings Opsonophagocytosis assays in fresh blood showed baseline immunity towards GAS. The role of innate immunity was investigated by deposition of the first complement components of each pathway, specifically C1q, FB and MBL from normal human serum on GAS. C1q deposition was the highest followed by FB deposition while MBL deposition was undetectable, suggesting that CP and AP may be mainly activated by GAS. We confirmed this result using sera depleted of either C1q or FB, and serum deficient in MBL. Recombinant SMSB4 was produced and purified from Pichia pastoris. SMSB4 reduced the baseline immunity against GAS by decreasing the formation of CP- and AP-C3 convertases, subsequently affecting opsonisation and the release of anaphylatoxin. Conclusions/Significance Our results indicate that the complement-inhibitory function of SMSB4 promotes the survival of GAS in vitro and inferably in the microenvironment of the mite-infested skin. Understanding the tripartite interactions between host, parasite and microbial pathogens at a molecular level may serve as a basis to develop improved intervention strategies targeting scabies and associated bacterial infections. The molecular mechanisms that underpin the link between scabies and bacterial pathogens were unknown. We proposed that scabies mites play a role in the establishment, proliferation and transmission of opportunistic pathogens. We investigated here the synergy between mites and one of the most recognised mite associated pathogens, Streptococcus pyogenes. As part of the innate immune response mammals have a pre-programmed ability to recognise and immediately act against substances derived from fungal and bacterial microorganisms. This is mediated through a sequential biochemical cascade involving over 30 different proteins (complement system) which as a result of signal amplification triggers a rapid killing response. The complement cascade produces peptides that attract immune cells, increases vascular permeability, coats (opsonises) the surfaces of a pathogen, marking it for destruction, and directly disrupts foreign plasma membranes. To prevent complement mediated damage of their gut cells, scabies mites secrete several classes of complement inhibiting proteins into the mite gut and excrete them into the epidermal mite burrows. Furthermore, these inhibitors also provide protection for S. pyogenes. We verified here specifically the impact of the mite complement inhibitor SMSB4, to identify the molecular mechanisms behind the long recognised tendency of S. pyogenes to infect mite-induced skin lesions.
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Affiliation(s)
- Pearl M. Swe
- QIMR Berghofer Medical Research Institute, Infectious Diseases Department, Herston, Brisbane, Australia
| | - Lindsay D. Christian
- QIMR Berghofer Medical Research Institute, Infectious Diseases Department, Herston, Brisbane, Australia
| | - Hieng C. Lu
- QIMR Berghofer Medical Research Institute, Infectious Diseases Department, Herston, Brisbane, Australia
| | - Kadaba S. Sriprakash
- QIMR Berghofer Medical Research Institute, Infectious Diseases Department, Herston, Brisbane, Australia
| | - Katja Fischer
- QIMR Berghofer Medical Research Institute, Infectious Diseases Department, Herston, Brisbane, Australia
- * E-mail:
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42
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Karlsson C, Teleman J, Malmström J. Analysis of Bacterial Surface Interactions with Mass Spectrometry-Based Proteomics. Methods Mol Biol 2017; 1535:17-24. [PMID: 27914070 DOI: 10.1007/978-1-4939-6673-8_2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Host-pathogen protein-protein interaction networks are highly complex and dynamic. In this experimental protocol we describe a method to isolate host proteins attached to the bacterial surface followed by quantitative mass spectrometry based proteomics analysis. This technique provides an overview of the host-pathogen interaction network, which can be used to guide directed perturbations of the system, and to select target of specific interest for further studies.
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Affiliation(s)
- Christofer Karlsson
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, Biomedical Center D13, Lund 22184, Sweden
| | - Johan Teleman
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, Biomedical Center D13, Lund 22184, Sweden
- Department of Immunotechnology, Lund University, Medicon Village 406, Lund 22381, Sweden
| | - Johan Malmström
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, Biomedical Center D13, Lund 22184, Sweden.
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43
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Measuring Antibody Orientation at the Bacterial Surface. Methods Mol Biol 2016. [PMID: 27914090 DOI: 10.1007/978-1-4939-6673-8_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Many bacteria have the ability to interact with antibodies as a means to circumvent the immune response. This includes binding to the Fc portion of antibodies, effectively reversing the antibody orientation and thus decreasing the Fc-mediated immune signaling. Since antibody orientation at the bacterial surface has been shown to be important in human disease, it is valuable to be able to assess how antibodies are interacting with bacterial pathogens. Here, we describe a method to measure the proportion of human IgG that are bound via their Fc or Fabs to a bacterial surface. This is achieved by treating antibody-coated bacteria with the bacterial enzyme IdeS - which will cleave IgG into Fc and Fab fragments - and subsequently detect remaining fragments with fluorescent Fabs. The method is easy and fast, and the principle is most likely also applicable to other systems where distinguishing between antibody Fc and Fab binding is important.
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44
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Hatzi K, Catera R, Moreno Atanasio C, Fischetti VA, Allen SL, Kolitz JE, Rai KR, Chu CC, Chiorazzi N. Chronic lymphocytic leukemia immunoglobulins display bacterial reactivity that converges and diverges from auto-/poly-reactivity and IGHV mutation status. Clin Immunol 2016; 172:44-51. [DOI: 10.1016/j.clim.2016.08.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 08/24/2016] [Indexed: 01/22/2023]
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45
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Kanagavelu S, Flores C, Hagiwara S, Ruiz J, Hyun J, Cho EE, Sun F, Romero L, Shih DQ, Fukata M. TIR-Domain-Containing Adapter-Inducing Interferon- β (TRIF) Regulates CXCR5+ T helper Cells in the Intestine. ACTA ACUST UNITED AC 2016; 7. [PMID: 27853628 DOI: 10.4172/2155-9899.1000458] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
OBJECTIVE Establishing an effective humoral immunity is an important host defense mechanism in intestinal mucosa. T follicular helper (Tfh) cells are a spectrum of CXCR5 expressing T helper cells that induce antigen-specific B cell differentiation. Because the differentiation of T helper cells is largely regulated by innate immunity, we addressed whether TRIF signaling regulates Tfh cell differentiation and its ability to trigger humoral immune responses in the intestine. METHOD CD4+CXCR5+ T cells, B cells, and plasma cells in the Peyer's patches (PPs) of WT and TRIF-deficient (TrifLPS2) mice were analyzed by flow cytometry at the baseline, 9 days post primary infection, and 7 days post-secondary infection with Y. enterocolitica. Y. enterocolitica-specific CD4+CXCR5+ T cells were generated in vitro by co-culturing peritoneal macrophages with splenic naïve T cells in the presence of Y. enterocolitica lysate. WT and TrifLPS2 mice received CD4+CXCR5+ T cells isolated either from Y. enterocolitica-primed WT mice or generated in vitro. These mice were infected with Y. enterocolitica and followed up to 4 weeks. Y. enterocolitica-specific IgA and IgG were measured in stool and serum samples, respectively. RESULTS At baseline, CD4+CXCR5+ T cell proportion was higher but the proportion of B cells and plasma cells was lower in the PPs of TrifLPS2 mice compared to WT mice. After infection, the proportion of plasma cells also became higher in the PPs of TrifLPS2 mice compared to WT mice. Corresponding increase of Y. enterocolitica-specific stool IgA but not serum IgG was found in TrifLPS2 mice compared to WT mice. Both in vivo isolated and in vitro generated CD4+CXCR5+ T cells induced protective immunity against Y. enterocolitica infection. CONCLUSION Our results reveal a novel role of TRIF in the regulation of humoral immunity in the intestine that can be utilized as a basis for a unique vaccine strategy.
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Affiliation(s)
- Saravana Kanagavelu
- Division of Gastroenterology, Department of Medicine, F. Widjaja Foundation, Inflammatory Bowel and Immunology Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA; Division of Infectious Diseases and Immunology, Department of Biomedical Science, Medicine and Pediatrics, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Claudia Flores
- Division of Gastroenterology, Department of Medicine, F. Widjaja Foundation, Inflammatory Bowel and Immunology Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Shinichiro Hagiwara
- Division of Gastroenterology, Department of Medicine, F. Widjaja Foundation, Inflammatory Bowel and Immunology Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Jose Ruiz
- Division of Gastroenterology, Department of Medicine, F. Widjaja Foundation, Inflammatory Bowel and Immunology Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Jinhee Hyun
- Department of Cell Biology, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Ei E Cho
- Division of Gastroenterology, Department of Medicine, F. Widjaja Foundation, Inflammatory Bowel and Immunology Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Frank Sun
- Division of Gastroenterology, Department of Medicine, F. Widjaja Foundation, Inflammatory Bowel and Immunology Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Laura Romero
- Department of Microbiology & Immunology, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - David Q Shih
- Division of Gastroenterology, Department of Medicine, F. Widjaja Foundation, Inflammatory Bowel and Immunology Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Masayuki Fukata
- Division of Gastroenterology, Department of Medicine, F. Widjaja Foundation, Inflammatory Bowel and Immunology Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA; Department of Cell Biology, University of Miami Miller School of Medicine, Miami, Florida, USA
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46
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Saliva-Induced Clotting Captures Streptococci: Novel Roles for Coagulation and Fibrinolysis in Host Defense and Immune Evasion. Infect Immun 2016; 84:2813-23. [PMID: 27456827 PMCID: PMC5038080 DOI: 10.1128/iai.00307-16] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 07/18/2016] [Indexed: 11/20/2022] Open
Abstract
Streptococcal pharyngitis is among the most common bacterial infections, but the molecular mechanisms involved remain poorly understood. Here we investigate the interactions among three major players in streptococcal pharyngitis: streptococci, plasma, and saliva. We find that saliva activates the plasma coagulation system through both the extrinsic and the intrinsic pathways, entrapping the bacteria in fibrin clots. The bacteria escape the clots by activating host plasminogen. Our results identify a potential function for the intrinsic pathway of coagulation in host defense and a corresponding role for fibrinolysis in streptococcal immune evasion.
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Abstract
IgG4, the least represented human IgG subclass in serum, is an intriguing antibody with unique biological properties, such as the ability to undergo Fab-arm exchange and limit immune complex formation. The lack of effector functions, such as antibody-dependent cell-mediated cytotoxicity and complement-dependent cytotoxicity, is desirable for therapeutic purposes. IgG4 plays a protective role in allergy by acting as a blocking antibody, and inhibiting mast cell degranulation, but a deleterious role in malignant melanoma, by impeding IgG1-mediated anti-tumor immunity. These findings highlight the importance of understanding the interaction between IgG4 and Fcγ receptors. Despite a wealth of structural information for the IgG1 subclass, including complexes with Fcγ receptors, and structures for intact antibodies, high-resolution crystal structures were not reported for IgG4-Fc until recently. Here, we highlight some of the biological properties of human IgG4, and review the recent crystal structures of IgG4-Fc. We discuss the unexpected conformations adopted by functionally important Cγ2 domain loops, and speculate about potential implications for the interaction between IgG4 and FcγRs.
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Affiliation(s)
- Anna M Davies
- Randall Division of Cell and Molecular Biophysics, King's College London, London, UK.,Medical Research Council & Asthma UK Centre in Allergic Mechanisms of Asthma, London, UK
| | - Brian J Sutton
- Randall Division of Cell and Molecular Biophysics, King's College London, London, UK.,Medical Research Council & Asthma UK Centre in Allergic Mechanisms of Asthma, London, UK
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Waldemarson S, Kurbasic E, Krogh M, Cifani P, Berggård T, Borg Å, James P. Proteomic analysis of breast tumors confirms the mRNA intrinsic molecular subtypes using different classifiers: a large-scale analysis of fresh frozen tissue samples. Breast Cancer Res 2016; 18:69. [PMID: 27357824 PMCID: PMC4928264 DOI: 10.1186/s13058-016-0732-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 06/19/2016] [Indexed: 12/11/2022] Open
Abstract
Background Breast cancer is a complex and heterogeneous disease that is usually characterized by histological parameters such as tumor size, cellular arrangements/rearrangments, necrosis, nuclear grade and the mitotic index, leading to a set of around twenty subtypes. Together with clinical markers such as hormone receptor status, this classification has considerable prognostic value but there is a large variation in patient response to therapy. Gene expression profiling has provided molecular profiles characteristic of distinct subtypes of breast cancer that reflect the divergent cellular origins and degree of progression. Methods Here we present a large-scale proteomic and transcriptomic profiling study of 477 sporadic and hereditary breast cancer tumors with matching mRNA expression analysis. Unsupervised hierarchal clustering was performed and selected proteins from large-scale tandem mass spectrometry (MS/MS) analysis were transferred into a highly multiplexed targeted selected reaction monitoring assay to classify tumors using a hierarchal cluster and support vector machine with leave one out cross-validation. Results The subgroups formed upon unsupervised clustering agree very well with groups found at transcriptional level; however, the classifiers (genes or their respective protein products) differ almost entirely between the two datasets. In-depth analysis shows clear differences in pathways unique to each type, which may lie behind their different clinical outcomes. Targeted mass spectrometry analysis and supervised clustering correlate very well with subgroups determined by RNA classification and show convincing agreement with clinical parameters. Conclusions This work demonstrates the merits of protein expression profiling for breast cancer stratification. These findings have important implications for the use of genomics and expression analysis for the prediction of protein expression, such as receptor status and drug target expression. The highly multiplexed MS assay is easily implemented in standard clinical chemistry practice, allowing rapid and cheap characterization of tumor tissue suitable for directing the choice of treatment. Electronic supplementary material The online version of this article (doi:10.1186/s13058-016-0732-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Sofia Waldemarson
- Department of Immunotechnology, Lund University, Medicon Village, 223 81, Lund, Sweden
| | - Emila Kurbasic
- Department of Immunotechnology, Lund University, Medicon Village, 223 81, Lund, Sweden
| | - Morten Krogh
- Amber Biosciences AB, Skrivarevägen 9, 226 57, Lund, Sweden
| | - Paolo Cifani
- Department of Immunotechnology, Lund University, Medicon Village, 223 81, Lund, Sweden
| | | | - Åke Borg
- Department of Oncology, Lund University, Medicon Village, 223 81, Lund, Sweden
| | - Peter James
- Department of Immunotechnology, Lund University, Medicon Village, 223 81, Lund, Sweden. .,Turku Centre for Biotechnology, Åbo Akademi University, University of Turku Biocity, Tykistokatu 6, 20520, Turku, Finland.
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Whitehouse J, Flaxman A, Rollier C, O'Shea MK, Fallowfield J, Lindsay M, Gunner F, Knox K, Wyllie DH, Yamaguchi Y. Population variation in anti-S. aureus IgG isotypes influences surface protein A mediated immune subversion. Vaccine 2016; 34:1792-9. [PMID: 26921780 DOI: 10.1016/j.vaccine.2016.02.034] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Revised: 02/03/2016] [Accepted: 02/15/2016] [Indexed: 01/10/2023]
Abstract
BACKGROUND Staphylococcus aureus is a pathogen which causes life-threatening infection, the incidence of which rises during adult life. This, together with the emergence of drug-resistant strains and the expansion of more susceptible elderly populations, represents the rationale for the ongoing development of S. aureus vaccines targeting adult populations. Humoral responses to S. aureus naturally develop early in life, influence susceptibility to infection, and potentially influence the effect of vaccination. Despite this, the nature of pre-existing anti-S. aureus antibodies in healthy adult populations is not fully characterised. METHODS Immunoglobulin levels against S. aureus surface antigens were measured by a filter membrane enzyme-linked immunosorbent assay using fixed ΔSpA S. aureus as an antigen in serum samples obtained from three clinical cohorts comprising 133 healthy adult volunteers from 19 to 65 years of age. Functional capacity of antibody was also assessed, using antibody-mediated attachment of FITC-stained S. aureus to differentiated HL-60 cells. RESULTS Wide variation in the concentrations of immunoglobulins recognising S. aureus surface antigens was observed among individuals in all three cohorts. There was a decline of anti-S. aureus IgG1 with age, and a similar trend was observed in IgM, but not in IgA or other IgG sub-classes. Antibody mediated bacterial attachment to cells was associated with IgG1 and IgG3 concentrations in serum. The presence of SpA on the bacterial cell surface reduced antibody-mediated binding of bacteria to phagocytes in serum with low, but not high, levels of naturally occurring anti-S. aureus IgG3 antibodies. CONCLUSIONS Naturally acquired immunoglobulin responses to S. aureus are heterogeneous in populations and their concentrations alter during adulthood. Elevated IgG1 or IgG3 titres against S. aureus enhance S. aureus recognition by phagocytosis and may be correlates of natural protection and/or vaccine efficacy in adult populations.
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Affiliation(s)
- Julia Whitehouse
- Jenner Institute, Centre for Cellular & Molecular Physiology, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, United Kingdom
| | - Amy Flaxman
- Jenner Institute, Centre for Cellular & Molecular Physiology, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, United Kingdom
| | - Christine Rollier
- Oxford Vaccine Group, Department of Paediatrics, Centre for Clinical Vaccinology and Tropical Medicine, University of Oxford, Churchill Drive, Oxford OX3 7LE, United Kingdom
| | - Matthew K O'Shea
- Jenner Institute, Centre for Cellular & Molecular Physiology, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, United Kingdom; Department of Academic Medicine, Royal Centre for Defence Medicine, Birmingham B15 2SQ, United Kingdom
| | - Joanne Fallowfield
- Environmental Medicine and Science Division, Institute of Naval Medicine, Hampshire PO12 2DL, United Kingdom
| | - Michael Lindsay
- Environmental Medicine and Science Division, Institute of Naval Medicine, Hampshire PO12 2DL, United Kingdom
| | - Frances Gunner
- Environmental Medicine and Science Division, Institute of Naval Medicine, Hampshire PO12 2DL, United Kingdom
| | - Kyle Knox
- Nuffield Department of Primary Care Health Sciences, New Radcliffe House, 2nd floor, Walton Street, Jericho OX2 6NW, United Kingdom
| | - David H Wyllie
- Jenner Institute, Centre for Cellular & Molecular Physiology, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, United Kingdom; Nuffield Department of Medicine, Department of Microbiology, John Radcliffe Hospital, Oxford OX3 9DU, United Kingdom.
| | - Yuko Yamaguchi
- Jenner Institute, Centre for Cellular & Molecular Physiology, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, United Kingdom
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Epidemiology Analysis of Streptococcus pyogenes in a Hospital in Southern Taiwan by Use of the Updated emm Cluster Typing System. J Clin Microbiol 2015; 54:157-62. [PMID: 26560544 DOI: 10.1128/jcm.02089-15] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 11/05/2015] [Indexed: 12/14/2022] Open
Abstract
emm typing is the most widely used molecular typing method for the human pathogen Streptococcus pyogenes (group A streptococcus [GAS]). emm typing is based on a small variable region of the emm gene; however, the emm cluster typing system defines GAS types according to the nearly complete sequence of the emm gene. Therefore, emm cluster typing is considered to provide more information regarding the functional and structural properties of M proteins in different emm types of GAS. In the present study, 677 isolates collected between 1994 and 2008 in a hospital in southern Taiwan were analyzed by the emm cluster typing system. emm clusters A-C4, E1, E6, and A-C3 were the most prevalent emm cluster types and accounted for 67.4% of total isolates. emm clusters A-C4 and E1 were associated with noninvasive diseases, whereas E6 was significantly associated with both invasive and noninvasive manifestations. In addition, emm clusters D4, E2, and E3 were significantly associated with invasive manifestations. Furthermore, we found that the functional properties of M protein, including low fibrinogen-binding and high IgG-binding activities, were correlated significantly with invasive manifestations. In summary, the present study provides updated epidemiological information on GAS emm cluster types in southern Taiwan.
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