1
|
Mattos-Graner RO, Klein MI, Alves LA. The complement system as a key modulator of the oral microbiome in health and disease. Crit Rev Microbiol 2024; 50:138-167. [PMID: 36622855 DOI: 10.1080/1040841x.2022.2163614] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 12/22/2022] [Accepted: 12/23/2022] [Indexed: 01/10/2023]
Abstract
In this review, we address the interplay between the complement system and host microbiomes in health and disease, focussing on oral bacteria known to contribute to homeostasis or to promote dysbiosis associated with dental caries and periodontal diseases. Host proteins modulating complement activities in the oral environment and expression profiles of complement proteins in oral tissues were described. In addition, we highlight a sub-set of bacterial proteins involved in complement evasion and/or dysregulation previously characterized in pathogenic species (or strains), but further conserved among prototypical commensal species of the oral microbiome. Potential roles of these proteins in host-microbiome homeostasis and in the emergence of commensal strain lineages with increased virulence were also addressed. Finally, we provide examples of how commensal bacteria might exploit the complement system in competitive or cooperative interactions within the complex microbial communities of oral biofilms. These issues highlight the need for studies investigating the effects of the complement system on bacterial behaviour and competitiveness during their complex interactions within oral and extra-oral host sites.
Collapse
Affiliation(s)
- Renata O Mattos-Graner
- Department of Oral Diagnosis, Piracicaba Dental School, State University of Campinas (UNICAMP), Sao Paulo, Brazil
| | - Marlise I Klein
- Department of Oral Diagnosis, Piracicaba Dental School, State University of Campinas (UNICAMP), Sao Paulo, Brazil
| | - Lívia Araújo Alves
- Department of Oral Diagnosis, Piracicaba Dental School, State University of Campinas (UNICAMP), Sao Paulo, Brazil
- School of Dentistry, Cruzeiro do Sul University (UNICSUL), Sao Paulo, Brazil
| |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
Hayashida A, Saeed HN, Zhang F, Song Y, Liu J, Parks WC, Bispo PJM, Park PW. Sulfated motifs in heparan sulfate inhibit Streptococcus pneumoniae adhesion onto fibronectin and attenuate corneal infection. PROTEOGLYCAN RESEARCH 2023; 1:e9. [PMID: 38957622 PMCID: PMC11218895 DOI: 10.1002/pgr2.9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 07/26/2023] [Indexed: 07/04/2024]
Abstract
A large number of bacterial pathogens bind to host extracellular matrix (ECM) components. For example, many Gram-negative and Gram-positive pathogens express binding proteins for fibronectin (FN) on their cell surface. Mutagenesis studies of bacterial FN-binding proteins have demonstrated their importance in pathogenesis in preclinical animal models. However, means to draw on these findings to design therapeutic approaches that specifically target FN-bacteria interactions have not been successful because bacterial pathogens can elaborate several FN-binding proteins and also because FN is an essential protein and likely a nondruggable target. Here we report that select heparan compounds potently inhibit Streptococcus pneumoniae infection of injured corneas in mice. Using intact heparan sulfate (HS) and heparin (HP), heparinase-digested fragments of HS, HP oligosaccharides, and chemically or chemoenzymatically modified heparan compounds, we found that inhibition of S. pneumoniae corneal infection by heparan compounds is not mediated by simple charge effects but by a selective sulfate group. Removal of 2-O-sulfates significantly inhibited the ability of HP to inhibit S. pneumoniae corneal infection, whereas the addition of 2-O-sulfates to heparosan (H) significantly increased H's ability to inhibit bacterial corneal infection. Proximity ligation assays indicated that S. pneumoniae attaches directly to FN fibrils in the corneal epithelial ECM and that HS and HP specifically inhibit this binding interaction in a 2-O-sulfate-dependent manner. These data suggest that heparan compounds containing 2-O-sulfate groups protect against S. pneumoniae corneal infection by inhibiting bacterial attachment to FN fibrils in the subepithelial ECM of injured corneas. Moreover, 2-O-sulfated heparan compounds significantly inhibited corneal infection in immunocompromised hosts, by a clinical keratitis isolate of S. pneumoniae, and also when topically administered in a therapeutic manner. These findings suggest that the administration of nonanticoagulant 2-O-sulfated heparan compounds may represent a plausible approach to the treatment of S. pneumoniae keratitis.
Collapse
Affiliation(s)
- Atsuko Hayashida
- Department of Medicine, Boston Children’s Hospital, Boston, Massachusetts, USA
| | - Hajirah N. Saeed
- Department of Ophthalmology, Boston Children’s Hospital, Boston, Massachusetts, USA
- Department of Ophthalmology, Massachusetts Eye and Ear, Boston, Massachusetts, USA
| | - Fuming Zhang
- Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, New York, USA
| | - Yuefan Song
- Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, New York, USA
| | - Jian Liu
- Division of Medicinal Chemistry, University of North Carolina, Chapel Hill, North Carolina, USA
| | - William C. Parks
- Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Paulo J. M. Bispo
- Department of Ophthalmology, Massachusetts Eye and Ear, Boston, Massachusetts, USA
| | - Pyong Woo Park
- Department of Medicine, Boston Children’s Hospital, Boston, Massachusetts, USA
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA
| |
Collapse
|
4
|
Protection Efficacy of Monoclonal Antibodies Targeting Different Regions of Specific SzM Protein from Swine-Isolated Streptococcus equi ssp. zooepidemicus Strains. Microbiol Spectr 2022; 10:e0174222. [PMID: 36255327 PMCID: PMC9769693 DOI: 10.1128/spectrum.01742-22] [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] [Indexed: 01/05/2023] Open
Abstract
Streptococcus equi subsp. zooepidemicus (SEZ) has a wide host spectrum, including humans and domestic animals. The SEZ-caused swine streptococcicosis outbreak has occurred in several countries, and the swine-isolated strains usually have specific S. zooepidemicus M-like (szm) gene types. In this study, we found that the production of this specific szm gene (SzM protein) was an effective vaccine candidate. It could provide better protection with a 7-day interval immune procedure than the traditional vaccine strain ST171 and attenuate the strain ΔsezV against swine-isolated hypervirulent SEZ infections. According to this outcome, we developed monoclonal antibodies (McAbs) targeting the variable and conserved regions of this SzM protein, respectively. These McAbs all belong to the IgG1 isotype with a κ type light chain and have opsonophagocytic activity rather than agglutination or complement activation functions. We estimated the protection efficiency of the McAbs with 3 different passive immunotherapy programs. The anti-conserved region McAb can provide effective protection against swine-isolated SEZ infections with only the inconvenient immunotherapy program. It also partially works in preventing infection by other SEZ strains. In contrast, the anti-variable region McAb is only adapted to protect the host against a specific szm type SEZ strain isolated from pigs, but it is flexible for different immunotherapy programs. These data provide further information to guide the development of derived, genetically engineered McAbs that have potential applications in protecting hosts against swine-isolated, hypervirulent SEZ infections in the future. IMPORTANCE The swine-isolated SEZ, with its specific szm gene sequence, has impacted the pig feeding industry in China and North America and has led to serious economic loss. Though the SzM protein of SEZ has been proven to be an effective vaccine in preventing infection, most previous studies focused on horse-isolated strains, which have different szm gene types compared to swine-isolated strains. In this study, we developed the McAbs targeting the conserved and variable regions of this SzM protein from the swine-isolated hypervirulent strains and evaluated their protection efficiency. Our research provided information for the development of chimeric McAbs or other genetically engineered McAbs that have potential applications in protecting pigs against hypervirulent SEZ infections in the future.
Collapse
|
5
|
Tang X, Arora G, Matias J, Hart T, Cui Y, Fikrig E. A tick C1q protein alters infectivity of the Lyme disease agent by modulating interferon γ. Cell Rep 2022; 41:111673. [PMID: 36417869 PMCID: PMC9909562 DOI: 10.1016/j.celrep.2022.111673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 08/04/2022] [Accepted: 10/25/2022] [Indexed: 11/23/2022] Open
Abstract
In North America, the Lyme disease agent, Borrelia burgdorferi, is commonly transmitted by the black-legged tick, Ixodes scapularis. Tick saliva facilitates blood feeding and enhances pathogen survival and transmission. Here, we demonstrate that I. scapularis complement C1q-like protein 3 (IsC1ql3), a tick salivary protein, directly interacts with B. burgdorferi and is important during the initial stage of spirochetal infection of mice. Mice fed upon by B. burgdorferi-infected IsC1ql3-silenced ticks, or IsC1ql3-immunized mice fed upon by B. burgdorferi-infected ticks, have a lower spirochete burden during the early phase of infection compared with control animals. Mechanically, IsC1ql3 interacts with the globular C1q receptor present on the surface of CD4+ and CD8+ T cells, resulting in decreased production of interferon γ. IsC1ql3 is a C1q-domain-containing protein identified in arthropod vectors and has an important role in B. burgdorferi infectivity as the spirochete transitions from the tick to vertebrate host.
Collapse
Affiliation(s)
- Xiaotian Tang
- Section of Infectious Diseases, Department of Internal Medicine, School of Medicine, Yale University, New Haven, CT, USA.
| | - Gunjan Arora
- Section of Infectious Diseases, Department of Internal Medicine, School of Medicine, Yale University, New Haven, CT, USA
| | - Jaqueline Matias
- Section of Infectious Diseases, Department of Internal Medicine, School of Medicine, Yale University, New Haven, CT, USA
| | - Thomas Hart
- Section of Infectious Diseases, Department of Internal Medicine, School of Medicine, Yale University, New Haven, CT, USA
| | - Yingjun Cui
- Section of Infectious Diseases, Department of Internal Medicine, School of Medicine, Yale University, New Haven, CT, USA
| | - Erol Fikrig
- Section of Infectious Diseases, Department of Internal Medicine, School of Medicine, Yale University, New Haven, CT, USA
| |
Collapse
|
6
|
De Gaetano GV, Coppolino F, Lentini G, Famà A, Cullotta C, Raffaele I, Motta C, Teti G, Speziale P, Pietrocola G, Beninati C. Streptococcus pneumoniae
binds collagens and C1q
via
the SSURE repeats of the PfbB adhesin. Mol Microbiol 2022; 117:1479-1492. [PMID: 35570359 PMCID: PMC9328315 DOI: 10.1111/mmi.14920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 04/17/2022] [Accepted: 05/12/2022] [Indexed: 11/29/2022]
Abstract
The binding of Streptococcus pneumoniae to collagen is likely an important step in the pathogenesis of pneumococcal infections, but little is known of the underlying molecular mechanisms. Streptococcal surface repeats (SSURE) are highly conserved protein domains present in cell wall adhesins from different Streptococcus species. We find here that SSURE repeats of the pneumococcal adhesin plasminogen and fibronectin binding protein B (PfbB) bind to various types of collagen. Moreover, deletion of the pfbB gene resulted in a significant impairment of the ability of encapsulated or unencapsulated pneumococci to bind collagen. Notably, a PfbB SSURE domain is also bound to the complement component C1q that bears a collagen‐like domain and promotes adherence of pneumococci to host cells by acting as a bridge between bacteria and epithelial cells. Accordingly, deletion of PfbB or pre‐treatment with anti‐SSURE antibodies markedly decreased pneumococcal binding to C1q as well as C1q‐dependent adherence to epithelial and endothelial cells. Further data indicated that C1q promotes pneumococcal adherence by binding to integrin α2β1. In conclusion, our results indicate that the SSURE domains of the PfbB protein promote interactions of pneumococci with various types of collagen and with C1q. These repeats may be useful targets in strategies to control S. pneumoniae infections.
Collapse
Affiliation(s)
| | - Francesco Coppolino
- Department of BiomedicalDental and Imaging SciencesUniversity of MessinaMessinaItaly
| | - Germana Lentini
- Department of Human PathologyUniversity of MessinaMessinaItaly
| | - Agata Famà
- Department of Human PathologyUniversity of MessinaMessinaItaly
| | - Chiara Cullotta
- Department of Human PathologyUniversity of MessinaMessinaItaly
| | - Ivana Raffaele
- Department of Human PathologyUniversity of MessinaMessinaItaly
| | - Chiara Motta
- Department of Molecular MedicineUniversity of PaviaPaviaItaly
| | | | - Pietro Speziale
- Department of Molecular MedicineUniversity of PaviaPaviaItaly
| | | | - Concetta Beninati
- Department of Human PathologyUniversity of MessinaMessinaItaly
- Scylla Biotech SrlMessinaItaly
| |
Collapse
|
7
|
Syed S, Viazmina L, Mager R, Meri S, Haapasalo K. Streptococci and the complement system: interplay during infection, inflammation and autoimmunity. FEBS Lett 2020; 594:2570-2585. [PMID: 32594520 DOI: 10.1002/1873-3468.13872] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 06/12/2020] [Accepted: 06/15/2020] [Indexed: 11/09/2022]
Abstract
Streptococci are a broad group of Gram-positive bacteria. This genus includes various human pathogens causing significant morbidity and mortality. Two of the most important human pathogens are Streptococcus pneumoniae (pneumococcus) and Streptococcus pyogenes (group A streptococcus or GAS). Streptococcal pathogens have evolved to express virulence factors that enable them to evade complement-mediated attack. These include factor H-binding M (S. pyogenes) and pneumococcal surface protein C (PspC) (S. pneumoniae) proteins. In addition, S. pyogenes and S. pneumoniae express cytolysins (streptolysin and pneumolysin), which are able to destroy host cells. Sometimes, the interplay between streptococci, the complement, and antistreptococcal immunity may lead to an excessive inflammatory response or autoimmune disease. Understanding the fundamental role of the complement system in microbial clearance and the bacterial escape mechanisms is of paramount importance for understanding microbial virulence, in general, and, the conversion of commensals to pathogens, more specifically. Such insights may help to identify novel antibiotic and vaccine targets in bacterial pathogens to counter their growing resistance to commonly used antibiotics.
Collapse
Affiliation(s)
- Shahan Syed
- Department of Bacteriology and Immunology, University of Helsinki, Finland
| | - Larisa Viazmina
- Department of Bacteriology and Immunology, University of Helsinki, Finland
| | | | - Seppo Meri
- Department of Bacteriology and Immunology, University of Helsinki, Finland.,Humanitas University, Milano, Italy
| | - Karita Haapasalo
- Department of Bacteriology and Immunology, University of Helsinki, Finland
| |
Collapse
|
8
|
Lindholm M, Metsäniitty M, Granström E, Oscarsson J. Outer membrane vesicle-mediated serum protection in Aggregatibacter actinomycetemcomitans. J Oral Microbiol 2020; 12:1747857. [PMID: 32363008 PMCID: PMC7178816 DOI: 10.1080/20002297.2020.1747857] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 03/16/2020] [Accepted: 03/18/2020] [Indexed: 01/23/2023] Open
Abstract
Aggregatibacter actinomycetemcomitans belongs to the HACEK group of fastidious Gram-negative organisms, a recognized cause of infective endocarditis. A. actinomycetemcomitans is also implicated in periodontitis, with rapid progress in adolescents. We recently demonstrated that the major outer membrane protein, OmpA1 was critical for serum survival of the A. actinomycetemcomitans serotype a model strain, D7SS, and that the paralogue, OmpA2 could operate as a functional homologue to OmpA1 in mediating serum resistance. In the present work, an essentially serum-sensitive ompA1 ompA2 double mutant A. actinomycetemcomitans strain derivative was exploited to elucidate if A. actinomycetemcomitans OMVs can contribute to bacterial serum resistance. Indeed, supplementation of OMVs resulted in a dose-dependent increase of the survival of the serum-sensitive strain in incubations in 50% normal human serum (NHS). Whereas neither OmpA1 nor OmpA2 was required for the OMV-mediated serum protection, OMVs and LPS from an A. actinomycetemcomitans strain lacking the LPS O-antigen polysaccharide part were significantly impaired in protecting D7SS ompA1 ompA2. Our results using a complement system screen assay support a model where A. actinomycetemcomitans OMVs can act as a decoy, which can trigger complement activation in an LPS-dependent manner, and consume complement components to protect serum-susceptible bacterial cells.
Collapse
Affiliation(s)
- Mark Lindholm
- Oral Microbiology, Department of Odontology, Umeå University, Umeå, Sweden
| | - Marjut Metsäniitty
- Oral Microbiology, Department of Odontology, Umeå University, Umeå, Sweden
| | | | - Jan Oscarsson
- Oral Microbiology, Department of Odontology, Umeå University, Umeå, Sweden
| |
Collapse
|
9
|
Lukácsi S, Mácsik-Valent B, Nagy-Baló Z, Kovács KG, Kliment K, Bajtay Z, Erdei A. Utilization of complement receptors in immune cell-microbe interaction. FEBS Lett 2020; 594:2695-2713. [PMID: 31989596 DOI: 10.1002/1873-3468.13743] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 01/15/2020] [Accepted: 01/16/2020] [Indexed: 12/19/2022]
Abstract
The complement system is a major humoral component of immunity and is essential for the fast elimination of pathogens invading the body. In addition to its indispensable role in innate immunity, the complement system is also involved in pathogen clearance during the effector phase of adaptive immunity. The fastest way of killing the invader is lysis by the membrane attack complex, which is formed by the terminal components of the complement cascade. Not all pathogens are lysed however and, if opsonized by a variety of molecules, they undergo phagocytosis and disposal inside immune cells. The most important complement-derived opsonins are C1q, the first component of the classical pathway, MBL, the initiator of the lectin pathway and C3-derived activation fragments, including C3b, iC3b and C3d, which all serve as ligands for their corresponding receptors. In this review, we discuss how complement receptors are utilized by various immune cells to tackle invading microbes, or by pathogens to evade host response.
Collapse
Affiliation(s)
- Szilvia Lukácsi
- MTA-ELTE Immunology Research Group, Eötvös Loránd University, Budapest, Hungary
| | | | - Zsuzsa Nagy-Baló
- Department of Immunology, Eötvös Loránd University, Budapest, Hungary
| | - Kristóf G Kovács
- Department of Immunology, Eötvös Loránd University, Budapest, Hungary
| | | | - Zsuzsa Bajtay
- MTA-ELTE Immunology Research Group, Eötvös Loránd University, Budapest, Hungary.,Department of Immunology, Eötvös Loránd University, Budapest, Hungary
| | - Anna Erdei
- MTA-ELTE Immunology Research Group, Eötvös Loránd University, Budapest, Hungary.,Department of Immunology, Eötvös Loránd University, Budapest, Hungary
| |
Collapse
|
10
|
Bertuzzi M, Hayes GE, Bignell EM. Microbial uptake by the respiratory epithelium: outcomes for host and pathogen. FEMS Microbiol Rev 2019; 43:145-161. [PMID: 30657899 PMCID: PMC6435450 DOI: 10.1093/femsre/fuy045] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Accepted: 01/17/2019] [Indexed: 12/21/2022] Open
Abstract
Intracellular occupancy of the respiratory epithelium is a useful pathogenic strategy facilitating microbial replication and evasion of professional phagocytes or circulating antimicrobial drugs. A less appreciated but growing body of evidence indicates that the airway epithelium also plays a crucial role in host defence against inhaled pathogens, by promoting ingestion and quelling of microorganisms, processes that become subverted to favour pathogen activities and promote respiratory disease. To achieve a deeper understanding of beneficial and deleterious activities of respiratory epithelia during antimicrobial defence, we have comprehensively surveyed all current knowledge on airway epithelial uptake of bacterial and fungal pathogens. We find that microbial uptake by airway epithelial cells (AECs) is a common feature of respiratory host-microbe interactions whose stepwise execution, and impacts upon the host, vary by pathogen. Amidst the diversity of underlying mechanisms and disease outcomes, we identify four key infection scenarios and use best-characterised host-pathogen interactions as prototypical examples of each. The emergent view is one in which effi-ciency of AEC-mediated pathogen clearance correlates directly with severity of disease outcome, therefore highlighting an important unmet need to broaden our understanding of the antimicrobial properties of respiratory epithelia and associated drivers of pathogen entry and intracellular fate.
Collapse
Affiliation(s)
- Margherita Bertuzzi
- Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health. The University of Manchester, Manchester Academic Health Science Centre, Core Technology Facility, Grafton Street, Manchester M13 9NT, UK
- Lydia Becker Institute of Immunology and Inflammation, Biology, Medicine and Health. The University of Manchester, Manchester Academic Health Science Centre
| | - Gemma E Hayes
- Northern Devon Healthcare NHS Trust, North Devon District Hospital, Raleigh Park, Barnstaple EX31 4JB, UK
| | - Elaine M Bignell
- Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health. The University of Manchester, Manchester Academic Health Science Centre, Core Technology Facility, Grafton Street, Manchester M13 9NT, UK
- Lydia Becker Institute of Immunology and Inflammation, Biology, Medicine and Health. The University of Manchester, Manchester Academic Health Science Centre
| |
Collapse
|
11
|
Complement depletion and Coombs positivity in pneumococcal hemolytic uremic syndrome (pnHUS). Case series and plea to revisit an old pathogenetic concept. Int J Med Microbiol 2018; 308:1096-1104. [PMID: 30177469 DOI: 10.1016/j.ijmm.2018.08.007] [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: 05/25/2018] [Revised: 08/21/2018] [Accepted: 08/27/2018] [Indexed: 12/27/2022] Open
Abstract
Hemolytic uremic syndrome is a rare complication of invasive pneumococcal infection (pnHUS). Its pathogenesis is poorly understood, and treatment remains controversial. The emerging role of complement in various forms of HUS warrants a new look at this "old" disease. We performed a retrospective analysis of clinical and laboratory features of three sequential cases of pnHUS since 2008 associated with pneumonia/pleural empyema, two due to Streptococcus pneumoniae serotype 19 A. Profound depletion of complement C3 (and less of C4) was observed in two patients. One patient was Coombs test positive. Her red blood cells (RBCs) strongly agglutinated with blood group compatible donor serum at 0 °C, but not at 37 °C. All three patients were treated with hemodialysis, concentrated RBCs, and platelets. Patient 2 received frozen plasma for hepatic failure with coagulation factor depletion. Intravenous immunoglobulin infusion, intended to neutralize pneumococcal neuraminidase in patient 3, was associated with rapid normalization of platelets and cessation of hemolysis. Two patients recovered without sequelae or disease recurrence. Patient 2 died within 2½ days of admission due to complicating Pseudomonas aeruginosa sepsis and multiorgan failure. Our observations suggest that pnHUS can be associated with dramatic, transient complement consumption early in the course of the disease, probably via the alternative pathway. A critical review of the literature and the reported cases argue against the postulated pathological role of preformed antibodies against the neuraminidase-exposed Thomsen-Friedenreich neoantigen (T antigen) in pnHUS. The improved understanding of complement regulation and bacterial strategies of complement evasion allows to propose a testable, new pathogenetic model of pnHUS. This model shifts emphasis from the action of natural anti-T antibodies toward impaired Complement Factor H (CFH) binding and function on desialylated membranes. Removal of neuraminic acid residues converts (protected) self to non-self surfaces that supports membrane attack complex (MAC) assembly. Complement activation is potentially exacerbated by decreased CFH availability following tight CFH binding to pneumococcal evasion proteins and/or by the presence of genetic variants of complement regulator proteins. Detailed clinical and experimental investigations are warranted to better understand the role of unregulated complement activation in pnHUS. Instead of avoidance of plasma, a new, integrated model is evolving, which may include short-term therapeutic complement blockade, particularly where genetic or functional APC dysregulation is suspected, in addition to bacterial elimination and, potentially, neuraminidase neutralization.
Collapse
|
12
|
Deng S, Xu T, Fang Q, Yu L, Zhu J, Chen L, Liu J, Zhou R. The Surface-Exposed Protein SntA Contributes to Complement Evasion in Zoonotic Streptococcus suis. Front Immunol 2018; 9:1063. [PMID: 29868022 PMCID: PMC5964162 DOI: 10.3389/fimmu.2018.01063] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2018] [Accepted: 04/27/2018] [Indexed: 12/20/2022] Open
Abstract
Streptococcus suis is an emerging zoonotic pathogen causing streptococcal toxic shock like syndrome (STSLS), meningitis, septicemia, and even sudden death in human and pigs. Serious septicemia indicates this bacterium can evade the host complement surveillance. In our previous study, a functionally unknown protein SntA of S. suis has been identified as a heme-binding protein, and contributes to virulence in pigs. SntA can interact with the host antioxidant protein AOP2 and consequently inhibit its antioxidant activity. In the present study, SntA is identified as a cell wall anchored protein that functions as an important player in S. suis complement evasion. The C3 deposition and membrane attack complex (MAC) formation on the surface of sntA-deleted mutant strain ΔsntA are demonstrated to be significantly higher than the parental strain SC-19 and the complementary strain CΔsntA. The abilities of anti-phagocytosis, survival in blood, and in vivo colonization of ΔsntA are obviously reduced. SntA can interact with C1q and inhibit hemolytic activity via the classical pathway. Complement activation assays reveal that SntA can also directly activate classical and lectin pathways, resulting in complement consumption. These two complement evasion strategies may be crucial for the pathogenesis of this zoonotic pathogen. Concerning that SntA is a bifunctional 2′,3′-cyclic nucleotide 2′-phosphodiesterase/3′-nucleotidase in many species of Gram-positive bacteria, these complement evasion strategies may have common biological significance.
Collapse
Affiliation(s)
- Simin Deng
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Tong Xu
- College of Life Science and Technology, Huazhong Agriculture University, Wuhan, China
| | - Qiong Fang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Lei Yu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Jiaqi Zhu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Long Chen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Jiahui Liu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Rui Zhou
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Cooperative Innovation Center of Sustainable Pig Production, Wuhan, China.,International Research Center for Animal Diseases (MOST), Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Wuhan, China
| |
Collapse
|
13
|
Garcia BL, Zwarthoff SA, Rooijakkers SHM, Geisbrecht BV. Novel Evasion Mechanisms of the Classical Complement Pathway. THE JOURNAL OF IMMUNOLOGY 2017; 197:2051-60. [PMID: 27591336 DOI: 10.4049/jimmunol.1600863] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 06/23/2016] [Indexed: 12/20/2022]
Abstract
Complement is a network of soluble and cell surface-associated proteins that gives rise to a self-amplifying, yet tightly regulated system with fundamental roles in immune surveillance and clearance. Complement becomes activated on the surface of nonself cells by one of three initiating mechanisms known as the classical, lectin, and alternative pathways. Evasion of complement function is a hallmark of invasive pathogens and hematophagous organisms. Although many complement-inhibition strategies hinge on hijacking activities of endogenous complement regulatory proteins, an increasing number of uniquely evolved evasion molecules have been discovered over the past decade. In this review, we focus on several recent investigations that revealed mechanistically distinct inhibitors of the classical pathway. Because the classical pathway is an important and specific mediator of various autoimmune and inflammatory disorders, in-depth knowledge of novel evasion mechanisms could direct future development of therapeutic anti-inflammatory molecules.
Collapse
Affiliation(s)
- Brandon L Garcia
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS 66506; and
| | - Seline A Zwarthoff
- Medical Microbiology, University Medical Center Utrecht, 3584 CX Utrecht, the Netherlands
| | - Suzan H M Rooijakkers
- Medical Microbiology, University Medical Center Utrecht, 3584 CX Utrecht, the Netherlands
| | - Brian V Geisbrecht
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS 66506; and
| |
Collapse
|
14
|
Andre GO, Converso TR, Politano WR, Ferraz LFC, Ribeiro ML, Leite LCC, Darrieux M. Role of Streptococcus pneumoniae Proteins in Evasion of Complement-Mediated Immunity. Front Microbiol 2017; 8:224. [PMID: 28265264 PMCID: PMC5316553 DOI: 10.3389/fmicb.2017.00224] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 01/31/2017] [Indexed: 12/14/2022] Open
Abstract
The complement system plays a central role in immune defense against Streptococcus pneumoniae. In order to evade complement attack, pneumococci have evolved a number of mechanisms that limit complement mediated opsonization and subsequent phagocytosis. This review focuses on the strategies employed by pneumococci to circumvent complement mediated immunity, both in vitro and in vivo. At last, since many of the proteins involved in interactions with complement components are vaccine candidates in different stages of validation, we explore the use of these antigens alone or in combination, as potential vaccine approaches that aim at elimination or drastic reduction in the ability of this bacterium to evade complement.
Collapse
Affiliation(s)
- Greiciely O Andre
- Laboratório de Biologia Celular e Molecular de Microrganismos, Universidade São Francisco Bragança Paulista, Brazil
| | - Thiago R Converso
- Centro de Biotecnologia, Instituto ButantanSão Paulo, Brazil; Programa de Pós-graduação Interunidades em Biotecnologia, Universidade de São PauloSão Paulo, Brazil
| | - Walter R Politano
- Laboratório de Biologia Celular e Molecular de Microrganismos, Universidade São Francisco Bragança Paulista, Brazil
| | - Lucio F C Ferraz
- Laboratório de Biologia Celular e Molecular de Microrganismos, Universidade São Francisco Bragança Paulista, Brazil
| | - Marcelo L Ribeiro
- Laboratório de Farmacologia, Universidade São Francisco Bragança Paulista, Brazil
| | | | - Michelle Darrieux
- Laboratório de Biologia Celular e Molecular de Microrganismos, Universidade São Francisco Bragança Paulista, Brazil
| |
Collapse
|
15
|
Wang X, Li J, Chen S, Shen X, Yang X, Teng Y, Deng L, Wang Y, Chen J, Wang X, Huang N. Knockdown of HMGN2 increases the internalization of Klebsiella pneumoniae by respiratory epithelial cells through the regulation of α5β1 integrin expression. Int J Mol Med 2016; 38:737-46. [PMID: 27460641 PMCID: PMC4990306 DOI: 10.3892/ijmm.2016.2690] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2015] [Accepted: 07/11/2016] [Indexed: 01/13/2023] Open
Abstract
Integrin receptors, a large family of adhesion receptors, are involved in the attachment of Klebsiella pneumoniae to respiratory epithelial cells, and subsequently cause the internalization of K. pneumoniae by host cells. Although a number of molecules have been reported to regulate the expression and activity of integrin receptors in respiratory epithelial cells, the specific underlying molecular mechanisms remain largely unknown. High mobility group nucleosomal binding domain 2 (HMGN2), a non-histone nuclear protein, is present in eukaryotic cells as a ubiquitous nuclear protein. Our previous studies have demonstrated that HMGN2 affects chromatin function and modulates the expression of antibacterial peptide in A549 cells exposed to lipopolysaccharide, which indicates the critical role of HMGN2 in innate immune responses. In addition, our cDNA microarray analysis suggested that HMGN2 knockdown induced the enhanced expression of α5β1 integrin in A549 cells. Therefore, we hypothesized that intercellular HMGN2 may mediate the internalization of K. pneumoniae by altering the expression of α5β1 integrin. Using the A549 cell line, we demonstrated that HMGN2 knockdown induced the increased expression of α5β1 integrin on cell membranes, which resulted in a significant increase in K. pneumoniae internalization. Further results revealed that HMGN2 silencing induced the expression of talin and the activation of α5β1 integrin, which led to actin polymerization following the phosphorylation of FAK and Src. This study suggests a possible therapeutic application for bacterial internalization by targeting HMGN2 in order to treat K. pneumoniae infection.
Collapse
Affiliation(s)
- Xinyuan Wang
- Department of Pathophysiology, Research Unit of Infection and Immunity, West China College of Basic and Forensic Medicine, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Jingyu Li
- Department of Pathophysiology, Research Unit of Infection and Immunity, West China College of Basic and Forensic Medicine, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Shanze Chen
- Department of Pathophysiology, Research Unit of Infection and Immunity, West China College of Basic and Forensic Medicine, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Xiaofei Shen
- Department of Pathophysiology, Research Unit of Infection and Immunity, West China College of Basic and Forensic Medicine, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Xiaolong Yang
- Department of Pathophysiology, Research Unit of Infection and Immunity, West China College of Basic and Forensic Medicine, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Yan Teng
- Department of Pathophysiology, Research Unit of Infection and Immunity, West China College of Basic and Forensic Medicine, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Luxia Deng
- Department of Pathophysiology, Research Unit of Infection and Immunity, West China College of Basic and Forensic Medicine, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Yi Wang
- Department of Pathophysiology, Research Unit of Infection and Immunity, West China College of Basic and Forensic Medicine, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Junli Chen
- Department of Pathophysiology, Research Unit of Infection and Immunity, West China College of Basic and Forensic Medicine, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Xiaoying Wang
- Department of Pathophysiology, Research Unit of Infection and Immunity, West China College of Basic and Forensic Medicine, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Ning Huang
- Department of Pathophysiology, Research Unit of Infection and Immunity, West China College of Basic and Forensic Medicine, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| |
Collapse
|
16
|
Roma-Rodrigues C, Alves-Barroco C, Raposo LR, Costa MN, Fortunato E, Baptista PV, Fernandes AR, Santos-Sanches I. Infection of human keratinocytes by Streptococcus dysgalactiae subspecies dysgalactiae isolated from milk of the bovine udder. Microbes Infect 2016; 18:290-3. [DOI: 10.1016/j.micinf.2015.11.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 11/16/2015] [Accepted: 11/21/2015] [Indexed: 10/22/2022]
|
17
|
Aung KM, Sjöström AE, von Pawel-Rammingen U, Riesbeck K, Uhlin BE, Wai SN. Naturally Occurring IgG Antibodies Provide Innate Protection against Vibrio cholerae Bacteremia by Recognition of the Outer Membrane Protein U. J Innate Immun 2016; 8:269-83. [PMID: 26934383 DOI: 10.1159/000443646] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 12/24/2015] [Indexed: 01/18/2023] Open
Abstract
Cholera epidemics are caused by Vibrio cholerae serogroups O1 and O139, whereas strains collectively known as non-O1/non-O139 V. cholerae are found in cases of extraintestinal infections and bacteremia. The mechanisms and factors influencing the occurrence of bacteremia and survival of V. cholerae in normal human serum have remained unclear. We found that naturally occurring IgG recognizing V. cholerae outer membrane protein U (OmpU) mediates a serum-killing effect in a complement C1q-dependent manner. Moreover, outer membrane vesicles (OMVs) containing OmpU caused enhanced survival of highly serum-sensitive classical V. cholerae in a dose-dependent manner. OMVs from wild-type and ompU mutant V. cholerae thereby provided a novel means to verify by extracellular transcomplementation the involvement of OmpU. Our data conclusively indicate that loss, or reduced expression, of OmpU imparts resistance to V. cholerae towards serum killing. We propose that the difference in OmpU protein levels is a plausible reason for differences in serum resistance and the ability to cause bacteremia observed among V. cholerae biotypes. Our findings provide a new perspective on how naturally occurring antibodies, perhaps induced by members of the microbiome, may play a role in the recognition of pathogens and the provocation of innate immune defense against bacteremia.
Collapse
Affiliation(s)
- Kyaw Min Aung
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Department of Molecular Biology, Umex00E5; University, Umex00E5;, Sweden
| | | | | | | | | | | |
Collapse
|
18
|
Kouser L, Madhukaran SP, Shastri A, Saraon A, Ferluga J, Al-Mozaini M, Kishore U. Emerging and Novel Functions of Complement Protein C1q. Front Immunol 2015; 6:317. [PMID: 26175731 PMCID: PMC4484229 DOI: 10.3389/fimmu.2015.00317] [Citation(s) in RCA: 121] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 06/02/2015] [Indexed: 02/02/2023] Open
Abstract
Complement protein C1q, the recognition molecule of the classical pathway, performs a diverse range of complement and non-complement functions. It can bind various ligands derived from self, non-self, and altered self and modulate the functions of immune and non-immune cells including dendritic cells and microglia. C1q involvement in the clearance of apoptotic cells and subsequent B cell tolerance is more established now. Recent evidence appears to suggest that C1q plays an important role in pregnancy where its deficiency and dysregulation can have adverse effects, leading to preeclampsia, missed abortion, miscarriage or spontaneous loss, and various infections. C1q is also produced locally in the central nervous system, and has a protective role against pathogens and possible inflammatory functions while interacting with aggregated proteins leading to neurodegenerative diseases. C1q role in synaptic pruning, and thus CNS development, its anti-cancer effects as an immune surveillance molecule, and possibly in aging are currently areas of extensive research.
Collapse
Affiliation(s)
- Lubna Kouser
- Centre for Infection, Immunity and Disease Mechanisms, College of Health and Life Sciences, Brunel University London , Uxbridge , UK
| | - Shanmuga Priyaa Madhukaran
- Centre for Infection, Immunity and Disease Mechanisms, College of Health and Life Sciences, Brunel University London , Uxbridge , UK ; Centre for Biotechnology and Bioinformatics, Jawaharlal Nehru Institute for Advanced Studies, School of Life Sciences , Secunderabad , India
| | - Abhishek Shastri
- St. Ann's Hospital, Dorset Healthcare University NHS Foundation Trust , Poole , UK
| | - Anuvinder Saraon
- Centre for Infection, Immunity and Disease Mechanisms, College of Health and Life Sciences, Brunel University London , Uxbridge , UK
| | - Janez Ferluga
- Centre for Infection, Immunity and Disease Mechanisms, College of Health and Life Sciences, Brunel University London , Uxbridge , UK
| | - Maha Al-Mozaini
- Department of Infection and Immunity, King Faisal Specialist Hospital and Research Centre , Riyadh , Saudi Arabia
| | - Uday Kishore
- Centre for Infection, Immunity and Disease Mechanisms, College of Health and Life Sciences, Brunel University London , Uxbridge , UK
| |
Collapse
|
19
|
Asmat TM, Agarwal V, Saleh M, Hammerschmidt S. Endocytosis of Streptococcus pneumoniae via the polymeric immunoglobulin receptor of epithelial cells relies on clathrin and caveolin dependent mechanisms. Int J Med Microbiol 2014; 304:1233-46. [PMID: 25455218 DOI: 10.1016/j.ijmm.2014.10.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 09/18/2014] [Accepted: 10/05/2014] [Indexed: 12/17/2022] Open
Abstract
Colonization of Streptococcus pneumoniae (pneumococci) is a prerequisite for bacterial dissemination and their capability to enter the bloodstream. Pneumococci have evolved various successful strategies to colonize the mucosal epithelial barrier of humans. A pivotal mechanism of host cell invasion implicated with invasive diseases is promoted by the interaction of pneumococcal PspC with the polymeric Ig-receptor (pIgR). However, the mechanism(s) of pneumococcal endocytosis and the intracellular route of pneumococci upon uptake by the PspC-pIgR-interaction are not known. Here, we demonstrate by using a combination of pharmacological inhibitors and genetics interference approaches the involvement of active dynamin-dependent caveolae and clathrin-coated vesicles for pneumococcal uptake via the PspC-pIgR mechanism. Depleting cholesterol from host cell membranes and disruption of lipid microdomains impaired pneumococcal internalization. Moreover, chemical inhibition of clathrin or functional inactivation of dynamin, caveolae or clathrin by RNA interference significantly affected pneumococcal internalization suggesting that clathrin-mediated endocytosis (CME) and caveolae are involved in the bacterial uptake process. Confocal fluorescence microscopy of pIgR-expressing epithelial cells infected with pneumococci or heterologous Lactococcus lactis expressing PspC demonstrated bacterial co-localization with fluorescent-tagged clathrin and early as well as recycling or late endosomal markers such as Lamp1, Rab5, Rab4, and Rab7, respectively. In conclusion these data suggest that PspC-promoted uptake is mediated by both CME and caveolae. After endocytosis pneumococci are routed via the endocytic pathway into early endosomes and are then sorted into recycling or late endosomes, which can result in pneumococcal killing in phagolysosomes or transcytosis via recycling endosomes.
Collapse
Affiliation(s)
- Tauseef M Asmat
- Department Genetics of Microorganisms, Interfaculty Institute for Genetics and Functional Genomics, Ernst-Moritz-Arndt Universität Greifswald, Friedrich-Ludwig-Jahn-Strasse 15a, D-17487 Greifswald, Germany; Pediatric Infectious Diseases, Department of Pediatrics, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Vaibhav Agarwal
- Department Genetics of Microorganisms, Interfaculty Institute for Genetics and Functional Genomics, Ernst-Moritz-Arndt Universität Greifswald, Friedrich-Ludwig-Jahn-Strasse 15a, D-17487 Greifswald, Germany; Department of Laboratory Medicine, Medical Protein Chemistry, Malmö University Hospital, Lund University, Malmö, Sweden
| | - Malek Saleh
- Department Genetics of Microorganisms, Interfaculty Institute for Genetics and Functional Genomics, Ernst-Moritz-Arndt Universität Greifswald, Friedrich-Ludwig-Jahn-Strasse 15a, D-17487 Greifswald, Germany
| | - Sven Hammerschmidt
- Department Genetics of Microorganisms, Interfaculty Institute for Genetics and Functional Genomics, Ernst-Moritz-Arndt Universität Greifswald, Friedrich-Ludwig-Jahn-Strasse 15a, D-17487 Greifswald, Germany.
| |
Collapse
|
20
|
Okumura CYM, Nizet V. Subterfuge and sabotage: evasion of host innate defenses by invasive gram-positive bacterial pathogens. Annu Rev Microbiol 2014; 68:439-58. [PMID: 25002085 DOI: 10.1146/annurev-micro-092412-155711] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The development of a severe invasive bacterial infection in an otherwise healthy individual is one of the most striking and fascinating aspects of human medicine. A small cadre of gram-positive pathogens of the genera Streptococcus and Staphylococcus stand out for their unique invasive disease potential and sophisticated ability to counteract the multifaceted components of human innate defense. This review illustrates how these leading human disease agents evade host complement deposition and activation, impede phagocyte recruitment and activation, resist the microbicidal activities of host antimicrobial peptides and reactive oxygen species, escape neutrophil extracellular traps, and promote and accelerate phagocyte cell death through the action of pore-forming cytolysins. Understanding the molecular basis of bacterial innate immune resistance can open new avenues for therapeutic intervention geared to disabling specific virulence factors and resensitizing the pathogen to host innate immune clearance.
Collapse
Affiliation(s)
- Cheryl Y M Okumura
- Department of Biology, Occidental College, Los Angeles, California 90041;
| | | |
Collapse
|
21
|
Sharif O, Gawish R, Warszawska JM, Martins R, Lakovits K, Hladik A, Doninger B, Brunner J, Korosec A, Schwarzenbacher RE, Berg T, Kralovics R, Colinge J, Mesteri I, Gilfillan S, Salmaggi A, Verschoor A, Colonna M, Knapp S. The triggering receptor expressed on myeloid cells 2 inhibits complement component 1q effector mechanisms and exerts detrimental effects during pneumococcal pneumonia. PLoS Pathog 2014; 10:e1004167. [PMID: 24945405 PMCID: PMC4055749 DOI: 10.1371/journal.ppat.1004167] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Accepted: 04/07/2014] [Indexed: 11/18/2022] Open
Abstract
Phagocytosis and inflammation within the lungs is crucial for host defense during bacterial pneumonia. Triggering receptor expressed on myeloid cells (TREM)-2 was proposed to negatively regulate TLR-mediated responses and enhance phagocytosis by macrophages, but the role of TREM-2 in respiratory tract infections is unknown. Here, we established the presence of TREM-2 on alveolar macrophages (AM) and explored the function of TREM-2 in the innate immune response to pneumococcal infection in vivo. Unexpectedly, we found Trem-2(-/-) AM to display augmented bacterial phagocytosis in vitro and in vivo compared to WT AM. Mechanistically, we detected that in the absence of TREM-2, pulmonary macrophages selectively produced elevated complement component 1q (C1q) levels. We found that these increased C1q levels depended on peroxisome proliferator-activated receptor-δ (PPAR-δ) activity and were responsible for the enhanced phagocytosis of bacteria. Upon infection with S. pneumoniae, Trem-2(-/-) mice exhibited an augmented bacterial clearance from lungs, decreased bacteremia and improved survival compared to their WT counterparts. This work is the first to disclose a role for TREM-2 in clinically relevant respiratory tract infections and demonstrates a previously unknown link between TREM-2 and opsonin production within the lungs.
Collapse
MESH Headings
- Animals
- Apoptosis
- Cell Line, Transformed
- Cells, Cultured
- Complement C1q/genetics
- Complement C1q/metabolism
- Cytokines/metabolism
- Disease Models, Animal
- Female
- Lung/cytology
- Lung/immunology
- Lung/metabolism
- Lung/pathology
- Macrophages, Alveolar/immunology
- Macrophages, Alveolar/metabolism
- Macrophages, Alveolar/pathology
- Male
- Membrane Glycoproteins/genetics
- Membrane Glycoproteins/metabolism
- Mice, Inbred C57BL
- Mice, Knockout
- Neutrophil Infiltration
- PPAR gamma/metabolism
- Phagocytosis
- Pneumonia, Pneumococcal/immunology
- Pneumonia, Pneumococcal/metabolism
- Pneumonia, Pneumococcal/pathology
- Receptors, Immunologic/genetics
- Receptors, Immunologic/metabolism
- Respiratory Mucosa/cytology
- Respiratory Mucosa/immunology
- Respiratory Mucosa/metabolism
- Respiratory Mucosa/pathology
- Survival Analysis
Collapse
Affiliation(s)
- Omar Sharif
- CeMM - Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
- Department of Medicine I, Laboratory of Infection Biology, Medical University of Vienna, Vienna, Austria
- * E-mail: (OS); (SK)
| | - Riem Gawish
- CeMM - Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
- Department of Medicine I, Laboratory of Infection Biology, Medical University of Vienna, Vienna, Austria
| | - Joanna M. Warszawska
- CeMM - Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
- Department of Medicine I, Laboratory of Infection Biology, Medical University of Vienna, Vienna, Austria
| | - Rui Martins
- CeMM - Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
- Department of Medicine I, Laboratory of Infection Biology, Medical University of Vienna, Vienna, Austria
| | - Karin Lakovits
- Department of Medicine I, Laboratory of Infection Biology, Medical University of Vienna, Vienna, Austria
| | - Anastasiya Hladik
- CeMM - Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
- Department of Medicine I, Laboratory of Infection Biology, Medical University of Vienna, Vienna, Austria
| | - Bianca Doninger
- CeMM - Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
- Department of Medicine I, Laboratory of Infection Biology, Medical University of Vienna, Vienna, Austria
| | - Julia Brunner
- CeMM - Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
- Department of Medicine I, Laboratory of Infection Biology, Medical University of Vienna, Vienna, Austria
| | - Ana Korosec
- CeMM - Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
- Department of Medicine I, Laboratory of Infection Biology, Medical University of Vienna, Vienna, Austria
| | - Roland E. Schwarzenbacher
- CeMM - Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
- Department of Medicine I, Laboratory of Infection Biology, Medical University of Vienna, Vienna, Austria
| | - Tiina Berg
- CeMM - Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Robert Kralovics
- CeMM - Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Jacques Colinge
- CeMM - Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Ildiko Mesteri
- Department of Pathology, Medical University of Vienna, Vienna, Austria
| | - Susan Gilfillan
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Andrea Salmaggi
- Department of Clinical Neurosciences, Istituto Nazionale Neurologico Carlo Besta, Milano, Italy
| | - Admar Verschoor
- Institute for Medical Microbiology, Immunology and Hygiene, Technical University Munich, Munich, Germany
| | - Marco Colonna
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Sylvia Knapp
- CeMM - Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
- Department of Medicine I, Laboratory of Infection Biology, Medical University of Vienna, Vienna, Austria
- * E-mail: (OS); (SK)
| |
Collapse
|
22
|
Agarwal V, Sroka M, Fulde M, Bergmann S, Riesbeck K, Blom AM. Binding of Streptococcus pneumoniae endopeptidase O (PepO) to complement component C1q modulates the complement attack and promotes host cell adherence. J Biol Chem 2014; 289:15833-44. [PMID: 24739385 DOI: 10.1074/jbc.m113.530212] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Gram-positive species Streptococcus pneumoniae is a human pathogen causing severe local and life-threatening invasive diseases associated with high mortality rates and death. We demonstrated recently that pneumococcal endopeptidase O (PepO) is a ubiquitously expressed, multifunctional plasminogen and fibronectin-binding protein facilitating host cell invasion and evasion of innate immunity. In this study, we found that PepO interacts directly with the complement C1q protein, thereby attenuating the classical complement pathway and facilitating pneumococcal complement escape. PepO binds both free C1q and C1 complex in a dose-dependent manner based on ionic interactions. Our results indicate that recombinant PepO specifically inhibits the classical pathway of complement activation in both hemolytic and complement deposition assays. This inhibition is due to direct interaction of PepO with C1q, leading to a strong activation of the classical complement pathway, and results in consumption of complement components. In addition, PepO binds the classical complement pathway inhibitor C4BP, thereby regulating downstream complement activation. Importantly, pneumococcal surface-exposed PepO-C1q interaction mediates bacterial adherence to host epithelial cells. Taken together, PepO facilitates C1q-mediated bacterial adherence, whereas its localized release consumes complement as a result of its activation following binding of C1q, thus representing an additional mechanism of human complement escape by this versatile pathogen.
Collapse
Affiliation(s)
| | | | - Marcus Fulde
- the Institute of Medical Microbiology and Hospital Epidemiology, Hannover Medical School, 30625 Hannover, Germany, and
| | - Simone Bergmann
- the Institute of Microbiology, Technische Universität Braunschweig, 38106 Braunschweig, Germany
| | - Kristian Riesbeck
- Medical Microbiology, Department of Laboratory Medicine Malmö, Lund University, 20502 Malmö, Sweden
| | - Anna M Blom
- From the Divisions of Medical Protein Chemistry and
| |
Collapse
|