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Jarlhelt I, Genster N, Kirketerp-Møller N, Skjoedt MO, Garred P. The ficolin response to LPS challenge in mice. Mol Immunol 2019; 108:121-127. [PMID: 30818229 DOI: 10.1016/j.molimm.2019.02.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 01/07/2019] [Accepted: 02/15/2019] [Indexed: 12/30/2022]
Abstract
The ficolins belong to an important family of pattern recognition molecules, which contributes to complement activation via the lectin pathway. How the ficolins respond to inflammatory stimuli remains only partly understood. In the present study, we investigated the ficolin A and ficolin B expression and protein distribution patterns in a mouse model of LPS-induced inflammation. The time- and tissue-specific expression of ficolin A and B was determined by real time PCR. Furthermore, ficolin protein levels in serum and bone marrow extracts from LPS challenged mice were determined by novel in-house developed sandwich ELISAs. Ficolin A was mainly expressed in liver and spleen. However, our data also suggested that ficolin A is expressed in bone marrow, which is the main site of ficolin B expression. The level of ficolin A and B expression was increased after stimulation with LPS in the investigated tissues. This was followed by a downregulation of expression, causing mRNA levels to return to baseline 24 h post LPS challenge. Protein levels appeared to follow the same pattern as the expression profiles, with an exception of ficolin B levels in serum, which kept increasing for 24 h. Ficolin A was likewise significantly increased in bronchoalveolar lavage fluid from mice infected with the fungi A. fumigatus, pointing towards a similar effect of the ficolins in non-sterile mouse models of inflammation. The results demonstrate that LPS-induced inflammation can induce a significant ficolin response, suggesting that the murine ficolins are acute phase reactants with increase in both mRNA expression and protein levels during systemic inflammation.
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Affiliation(s)
- Ida Jarlhelt
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Ninette Genster
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Nikolaj Kirketerp-Møller
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mikkel-Ole Skjoedt
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Peter Garred
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
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Jarlhelt I, Genster N, Kirketerp-Møller N, Skjødt MO, Garred P. The ficolin response to LPS-challenge in mice. Mol Immunol 2018. [DOI: 10.1016/j.molimm.2018.06.103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Genster N, Østrup O, Schjalm C, Mollnes TE, Cowland JB, Garred P. Ficolins do not alter host immune responses to lipopolysaccharide-induced inflammation in vivo. Mol Immunol 2017. [DOI: 10.1016/j.molimm.2017.06.134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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4
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Pilely K, Fumagalli S, Rosbjerg A, Genster N, Skjoedt MO, Perego C, Ferrante AMR, De Simoni MG, Garred P. C-Reactive Protein Binds to Cholesterol Crystals and Co-Localizes with the Terminal Complement Complex in Human Atherosclerotic Plaques. Front Immunol 2017; 8:1040. [PMID: 28900428 PMCID: PMC5581807 DOI: 10.3389/fimmu.2017.01040] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 08/11/2017] [Indexed: 12/24/2022] Open
Abstract
Inflammation is a part of the initial process leading to atherosclerosis and cholesterol crystals (CC), found in atherosclerotic plaques, which are known to induce complement activation. The pentraxins C-reactive protein (CRP), long pentraxin 3 (PTX3), and serum amyloid P component (SAP) are serum proteins associated with increased risk of cardiovascular events and these proteins have been shown to interact with the complement system. Whether the pentraxins binds to CC and mediate downstream complement-dependent inflammatory processes remains unknown. Binding of CRP, PTX3, and SAP to CC was investigated in vitro by flow cytometry and fluorescence microscopy. CRP, PTX3, and SAP bound to CC in a concentration-dependent manner. CRP and PTX3 interacted with the complement pattern recognition molecule C1q on CC by increasing the binding of both purified C1q and C1q in plasma. However, CRP was the strongest mediator of C1q binding and also the pentraxin that most potently elevated C1q-mediated complement activation. In a phagocytic assay using whole blood, we confirmed that phagocytosis of CC is complement dependent and initiated by C1q-mediated activation. The pathophysiological relevance of the in vitro observations was examined in vivo in human atherosclerotic plaques. CRP, PTX3, and SAP were all found in atherosclerotic plaques and were located mainly in the cholesterol-rich necrotic core, but co-localization with the terminal C5b-9 complement complex was only found for CRP. In conclusion, this study identifies CRP as a strong C1q recruiter and complement facilitator on CC, which may be highly relevant for the development of atherosclerosis.
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Affiliation(s)
- Katrine Pilely
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631, Faculty of Health and Medical Sciences, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Stefano Fumagalli
- Istituto di Ricerche Farmacologiche Mario Negri, Department of Neuroscience, IRCCS, Milan, Italy
| | - Anne Rosbjerg
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631, Faculty of Health and Medical Sciences, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Ninette Genster
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631, Faculty of Health and Medical Sciences, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Mikkel-Ole Skjoedt
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631, Faculty of Health and Medical Sciences, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Carlo Perego
- Istituto di Ricerche Farmacologiche Mario Negri, Department of Neuroscience, IRCCS, Milan, Italy
| | - Angela M R Ferrante
- Università Cattolica del S.Cuore, Istituto di Patologia Chirurgica, Fondazione "Policlinico Universitario A. Gemelli", Polo Scienze cardiovascolari e toraciche, Roma, Italy
| | - Maria-Grazia De Simoni
- Istituto di Ricerche Farmacologiche Mario Negri, Department of Neuroscience, IRCCS, Milan, Italy
| | - Peter Garred
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631, Faculty of Health and Medical Sciences, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
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Genster N, Østrup O, Schjalm C, Eirik Mollnes T, Cowland JB, Garred P. Ficolins do not alter host immune responses to lipopolysaccharide-induced inflammation in vivo. Sci Rep 2017; 7:3852. [PMID: 28634324 PMCID: PMC5478672 DOI: 10.1038/s41598-017-04121-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 05/09/2017] [Indexed: 11/17/2022] Open
Abstract
Ficolins are a family of pattern recognition molecules that are capable of activating the lectin pathway of complement. A limited number of reports have demonstrated a protective role of ficolins in animal models of infection. In addition, an immune modulatory role of ficolins has been suggested. Yet, the contribution of ficolins to inflammatory disease processes remains elusive. To address this, we investigated ficolin deficient mice during a lipopolysaccharide (LPS)-induced model of systemic inflammation. Although murine serum ficolin was shown to bind LPS in vitro, there was no difference between wildtype and ficolin deficient mice in morbidity and mortality by LPS-induced inflammation. Moreover, there was no difference between wildtype and ficolin deficient mice in the inflammatory cytokine profiles after LPS challenge. These findings were substantiated by microarray analysis revealing an unaltered spleen transcriptome profile in ficolin deficient mice compared to wildtype mice. Collectively, results from this study demonstrate that ficolins are not involved in host response to LPS-induced systemic inflammation.
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Affiliation(s)
- Ninette Genster
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Olga Østrup
- Center for Genomic Medicine, Rigshospitalet, Copenhagen University Hospital, Blegdamsvej 9, DK-2100, Copenhagen, Denmark
| | - Camilla Schjalm
- Department of Immunology, Oslo University Hospital, Rikshospitalet, 0424, Oslo, Norway
| | - Tom Eirik Mollnes
- Department of Immunology, Oslo University Hospital, Rikshospitalet, 0424, Oslo, Norway
- Research Laboratory, Nordland Hospital, Bodø, and K.J. Jebsen TREC, University of Tromsø, Tromsø, Norway
- Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, Trondheim, Norway
| | - Jack B Cowland
- The Granulocyte Research Laboratory, Department of Hematology, Copenhagen University Hospital, Copenhagen, Denmark
- Department of Clinical Genetics, Copenhagen University Hospital, Copenhagen, Denmark
| | - Peter Garred
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
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Rosbjerg A, Genster N, Pilely K, Garred P. Evasion Mechanisms Used by Pathogens to Escape the Lectin Complement Pathway. Front Microbiol 2017; 8:868. [PMID: 28553281 PMCID: PMC5427104 DOI: 10.3389/fmicb.2017.00868] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 04/28/2017] [Indexed: 12/21/2022] Open
Abstract
The complement system is a crucial defensive network that protects the host against invading pathogens. It is part of the innate immune system and can be initiated via three pathways: the lectin, classical and alternative activation pathway. Overall the network compiles a group of recognition molecules that bind specific patterns on microbial surfaces, a group of associated proteases that initiates the complement cascade, and a group of proteins that interact in proteolytic complexes or the terminal pore-forming complex. In addition, various regulatory proteins are important for controlling the level of activity. The result is a pro-inflammatory response meant to combat foreign microbes. Microbial elimination is, however, not a straight forward procedure; pathogens have adapted to their environment by evolving a collection of evasion mechanisms that circumvent the human complement system. Complement evasion strategies features different ways of exploiting human complement proteins and moreover features different pathogen-derived proteins that interfere with the normal processes. Accumulated, these mechanisms target all three complement activation pathways as well as the final common part of the cascade. This review will cover the currently known lectin pathway evasion mechanisms and give examples of pathogens that operate these to increase their chance of invasion, survival and dissemination.
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Affiliation(s)
- Anne Rosbjerg
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631, Rigshospitalet, Faculty of Health and Medical Sciences, University of CopenhagenCopenhagen, Denmark
| | - Ninette Genster
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631, Rigshospitalet, Faculty of Health and Medical Sciences, University of CopenhagenCopenhagen, Denmark
| | - Katrine Pilely
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631, Rigshospitalet, Faculty of Health and Medical Sciences, University of CopenhagenCopenhagen, Denmark
| | - Peter Garred
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631, Rigshospitalet, Faculty of Health and Medical Sciences, University of CopenhagenCopenhagen, Denmark
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Rosbjerg A, Genster N, Pilely K, Skjoedt MO, Stahl GL, Garred P. Complementary Roles of the Classical and Lectin Complement Pathways in the Defense against Aspergillus fumigatus. Front Immunol 2016; 7:473. [PMID: 27857715 PMCID: PMC5093123 DOI: 10.3389/fimmu.2016.00473] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2016] [Accepted: 10/19/2016] [Indexed: 11/26/2022] Open
Abstract
Aspergillus fumigatus infections are associated with a high mortality rate for immunocompromised patients. The complement system is considered to be important in protection against this fungus, yet the course of activation is unclear. The aim of this study was to unravel the role of the classical, lectin, and alternative pathways under both immunocompetent and immunocompromised conditions to provide a relevant dual-perspective on the response against A. fumigatus. Conidia (spores) from a clinical isolate of A. fumigatus were combined with various human serum types (including serum deficient of various complement components and serum from umbilical cord blood). We also combined this with inhibitors against C1q, mannose-binding lectin (MBL), and ficolin-2 before complement activation products and phagocytosis were detected by flow cytometry. Our results showed that alternative pathway amplified complement on A. fumigatus, but required classical and/or lectin pathway for initiation. In normal human serum, this initiation came primarily from the classical pathway. However, with a dysfunctional classical pathway (C1q-deficient serum), lectin pathway activated complement and mediated opsonophagocytosis through MBL. To model the antibody-decline in a compromised immune system, we used serum from normal umbilical cords and found MBL to be the key complement initiator. In another set of experiments, serum from patients with different kinds of immunoglobulin insufficiencies showed that the MBL lectin pathway contribution was highest in the samples with the lowest IgG/IgM binding. In conclusion, lectin pathway appears to be the primary route of complement activation in the absence of anti-A. fumigatus antibodies, whereas in a balanced immune state classical pathway is the main activator. This suggests a crucial role for the lectin pathway in innate immune protection against A. fumigatus in immunocompromised patients.
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Affiliation(s)
- Anne Rosbjerg
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Faculty of Health and Medical Sciences, Rigshospitalet, University of Copenhagen , Copenhagen , Denmark
| | - Ninette Genster
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Faculty of Health and Medical Sciences, Rigshospitalet, University of Copenhagen , Copenhagen , Denmark
| | - Katrine Pilely
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Faculty of Health and Medical Sciences, Rigshospitalet, University of Copenhagen , Copenhagen , Denmark
| | - Mikkel-Ole Skjoedt
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Faculty of Health and Medical Sciences, Rigshospitalet, University of Copenhagen , Copenhagen , Denmark
| | - Gregory L Stahl
- Department of Anesthesiology, Perioperative and Pain Medicine, Center for Experimental Therapeutics and Reperfusion Injury, Brigham and Women's Hospital, Harvard Medical School , Boston, MA , USA
| | - Peter Garred
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Faculty of Health and Medical Sciences, Rigshospitalet, University of Copenhagen , Copenhagen , Denmark
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Abstract
Mannose-binding lectin (MBL), collectin-10, collectin-11, and the ficolins (ficolin-1, ficolin-2, and ficolin-3) are soluble pattern recognition molecules in the lectin complement pathway. These proteins act as mediators of host defense and participate in maintenance of tissue homeostasis. They bind to conserved pathogen-specific structures and altered self-antigens and form complexes with the pentraxins to modulate innate immune functions. All molecules exhibit distinct expression in different tissue compartments, but all are found to a varying degree in the circulation. A common feature of these molecules is their ability to interact with a set of serine proteases named MASPs (MASP-1, MASP-2, and MASP-3). MASP-1 and -2 trigger the activation of the lectin pathway and MASP-3 may be involved in the activation of the alternative pathway of complement. Furthermore, MASPs mediate processes related to coagulation, bradykinin release, and endothelial and platelet activation. Variant alleles affecting expression and structure of the proteins have been associated with a variety of infectious and non-infectious diseases, most commonly as disease modifiers. Notably, the severe 3MC (Malpuech, Michels, Mingarelli, and Carnevale) embryonic development syndrome originates from rare mutations affecting either collectin-11 or MASP-3, indicating a broader functionality of the complement system than previously anticipated. This review summarizes the characteristics of the molecules in the lectin pathway.
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Affiliation(s)
- Peter Garred
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
| | - Ninette Genster
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Katrine Pilely
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Rafael Bayarri-Olmos
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Anne Rosbjerg
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Ying Jie Ma
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mikkel-Ole Skjoedt
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Rosbjerg A, Genster N, Pilely K, Skjoedt MO, Stahl GL, Garred P. Complementary roles of the classical and lectin complement pathways in the defense against Aspergillus fumigatus. Immunobiology 2016. [DOI: 10.1016/j.imbio.2016.06.165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Pilely K, Rosbjerg A, Genster N, Gal P, Pál G, Halvorsen B, Holm S, Aukrust P, Bakke SS, Sporsheim B, Nervik I, Niyonzima N, Bartels ED, Stahl GL, Mollnes TE, Espevik T, Garred P. Cholesterol crystals activate the lectin complement pathway via ficolin-2 and MBL – Implications for the progression of atherosclerosis. Immunobiology 2016. [DOI: 10.1016/j.imbio.2016.06.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Genster N, Præstekjær Cramer E, Rosbjerg A, Pilely K, Cowland JB, Garred P. Ficolins Promote Fungal Clearance in vivo and Modulate the Inflammatory Cytokine Response in Host Defense against Aspergillus fumigatus. J Innate Immun 2016; 8:579-588. [PMID: 27467404 PMCID: PMC6738752 DOI: 10.1159/000447714] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Revised: 06/20/2016] [Accepted: 06/20/2016] [Indexed: 01/24/2023] Open
Abstract
Aspergillus fumigatus is an opportunistic fungal pathogen that causes severe invasive infections in immunocompromised patients. Innate immunity plays a major role in protection against A. fumigatus. The ficolins are a family of soluble pattern recognition receptors that are capable of activating the lectin pathway of complement. Previous in vitro studies reported that ficolins bind to A. fumigatus, but their part in host defense against fungal infections in vivo is unknown. In this study, we used ficolin-deficient mice to investigate the role of ficolins during lung infection with A. fumigatus. Ficolin knockout mice showed significantly higher fungal loads in the lungs 24 h postinfection compared to wild-type mice. The delayed clearance of A. fumigatus in ficolin knockout mice could not be attributed to a compromised recruitment of inflammatory cells. However, it was revealed that ficolin knockout mice exhibited a decreased production of proinflammatory cytokines in the lungs compared to wild-type mice following A. fumigatus infection. The impaired clearance and cytokine production in ficolin knockout mice was independent of complement, as shown by equivalent levels of A. fumigatus-mediated complement activation in ficolin knockout mice and wild-type mice. In conclusion, this study demonstrates that ficolins are important in initial innate host defense against A. fumigatus infections in vivo.
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Affiliation(s)
- Ninette Genster
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Elisabeth Præstekjær Cramer
- The Granulocyte Research Laboratory, Department of Hematology, Copenhagen University Hospital, Copenhagen, Denmark
| | - Anne Rosbjerg
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Katrine Pilely
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jack Bernard Cowland
- The Granulocyte Research Laboratory, Department of Hematology, Copenhagen University Hospital, Copenhagen, Denmark
| | - Peter Garred
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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12
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Pilely K, Rosbjerg A, Genster N, Gal P, Pál G, Halvorsen B, Holm S, Aukrust P, Bakke SS, Sporsheim B, Nervik I, Niyonzima N, Bartels ED, Stahl GL, Mollnes TE, Espevik T, Garred P. Cholesterol Crystals Activate the Lectin Complement Pathway via Ficolin-2 and Mannose-Binding Lectin: Implications for the Progression of Atherosclerosis. J Immunol 2016; 196:5064-74. [PMID: 27183610 DOI: 10.4049/jimmunol.1502595] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 04/13/2016] [Indexed: 12/16/2023]
Abstract
Cholesterol crystals (CC) play an essential role in the formation of atherosclerotic plaques. CC activate the classical and the alternative complement pathways, but the role of the lectin pathway is unknown. We hypothesized that the pattern recognition molecules (PRMs) from the lectin pathway bind CC and function as an upstream innate inflammatory signal in the pathophysiology of atherosclerosis. We investigated the binding of the PRMs mannose-binding lectin (MBL), ficolin-1, ficolin-2, and ficolin-3, the associated serine proteases, and complement activation products to CC in vitro using recombinant proteins, specific inhibitors, as well as deficient and normal sera. Additionally, we examined the deposition of ficolin-2 and MBL in human carotid plaques by immunohistochemistry and fluorescence microscopy. The results showed that the lectin pathway was activated on CC by binding of ficolin-2 and MBL in vitro, resulting in activation and deposition of complement activation products. MBL bound to CC in a calcium-dependent manner whereas ficolin-2 binding was calcium-independent. No binding was observed for ficolin-1 or ficolin-3. MBL and ficolin-2 were present in human carotid plaques, and binding of MBL to CC was confirmed in vivo by immunohistochemistry, showing localization of MBL around CC clefts. Moreover, we demonstrated that IgM, but not IgG, bound to CC in vitro and that C1q binding was facilitated by IgM. In conclusion, our study demonstrates that PRMs from the lectin pathway recognize CC and provides evidence for an important role for this pathway in the inflammatory response induced by CC in the pathophysiology of atherosclerosis.
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Affiliation(s)
- Katrine Pilely
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen O, Denmark
| | - Anne Rosbjerg
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen O, Denmark
| | - Ninette Genster
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen O, Denmark
| | - Peter Gal
- Institute of Enzymology, Research Center for Natural Sciences, Hungarian Academy of Sciences, 1113 Budapest, Hungary
| | - Gábor Pál
- Department of Biochemistry, Eötvös Loránd University, 1117 Budapest, Hungary
| | - Bente Halvorsen
- Research Institute of Internal Medicine, Oslo University Hospital Rikshospitalet, 0424 Oslo, Norway; K.G. Jebsen Inflammation Research Center, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, 0318 Oslo, Norway
| | - Sverre Holm
- Research Institute of Internal Medicine, Oslo University Hospital Rikshospitalet, 0424 Oslo, Norway; Hospital for Rheumatic Diseases, 2609 Lillehammer, Norway
| | - Pål Aukrust
- Research Institute of Internal Medicine, Oslo University Hospital Rikshospitalet, 0424 Oslo, Norway; K.G. Jebsen Inflammation Research Center, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, 0318 Oslo, Norway
| | - Siril Skaret Bakke
- Center of Molecular Inflammation Research, Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, 7491 Trondheim, Norway
| | - Bjørnar Sporsheim
- Center of Molecular Inflammation Research, Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, 7491 Trondheim, Norway
| | - Ingunn Nervik
- Section for Children's and Women's Health, Department of Laboratory Medicine, Norwegian University of Science and Technology, 7491 Trondheim, Norway
| | - Nathalie Niyonzima
- Center of Molecular Inflammation Research, Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, 7491 Trondheim, Norway
| | - Emil D Bartels
- Department of Clinical Biochemistry, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen O, Denmark
| | - Gregory L Stahl
- Department of Anesthesiology, Perioperative and Pain Medicine, Center for Experimental Therapeutics and Reperfusion Injury, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115
| | - Tom Eirik Mollnes
- K.G. Jebsen Inflammation Research Center, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, 0318 Oslo, Norway; Department of Immunology, Oslo University Hospital Rikshospitalet, 0424 Oslo, Norway; Research Laboratory, Nordland Hospital, 8038 Bodø, Norway; and K.G. Jebsen Thrombosis Research and Expertise Center, University of Tromsø, 9019 Tromsø, Norway
| | - Terje Espevik
- Center of Molecular Inflammation Research, Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, 7491 Trondheim, Norway
| | - Peter Garred
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen O, Denmark;
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13
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Pilely K, Rosbjerg A, Genster N, Gál P, Pál G, Stahl GL, Mollnes TE, Espevik T, Garred P. Cholesterol crystals activate the lectin complement pathway via ficolin-2 and MBL - implications for the progression of atherosclerosis. The Journal of Immunology 2016. [DOI: 10.4049/jimmunol.196.supp.202.26] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
Cholesterol crystals (CC) play an essential role in the formation of atherosclerotic plaques by inducing inflammation and by functioning as an endogenous danger signal. CC activate the classical and the alternative complement pathways, but the role of the lectin pathway is unknown. In this study we hypothesized that pattern recognition molecules (PRM) from the lectin pathway bind CC and functions as an upstream innate inflammatory signal in the pathophysiology of atherosclerosis. We investigated the binding of the PRMs mannose-binding lectin (MBL), ficolin-1, ficolin-2, and ficolin-3, the associated serine proteases, and complement activation products to CC using recombinant proteins, specific inhibitors as well as deficient and normal sera. Binding was assessed by flow cytometry and microscopy. The results showed that the lectin pathway was activated on CC by binding of ficolin-2 and MBL, resulting in activation and deposition of complement activation products. MBL bound to CC in a calcium dependent manner while ficolin-2 binding was calcium independent. No binding was observed for ficolin-1 or ficolin-3. Moreover, we demonstrated that IgM, but not IgG bound to CC and that C1q binding was facilitated by IgM. In conclusion our study demonstrates that PRMs from the lectin pathway recognize CC and provides evidence for an important role for this pathway in the inflammatory response induced by CC in the pathophysiology of atherosclerosis.
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Affiliation(s)
- Katrine Pilely
- 1Fac. of Hlth. and Med. Sci., Univ. of Copenhagen, Denmark
| | - Anne Rosbjerg
- 1Fac. of Hlth. and Med. Sci., Univ. of Copenhagen, Denmark
| | | | - Péter Gál
- 2Inst. of Enzymology, Hungarian Acad. of Sci., Hungary
| | | | | | - Tom Eirik Mollnes
- 5Univ. of Olso, Norway
- 6Univ. of Tromsø, Norway
- 7Norwegian Univ. of Sci. and Technol., Norway
| | | | - Peter Garred
- 1Fac. of Hlth. and Med. Sci., Univ. of Copenhagen, Denmark
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Genster N, Cowland J, Cramer E, Rosbjerg A, Pilely K, Garred P. Ficolins promote fungal clearance during the early stage of pulmonary infection with Aspergillus fumigatus.. The Journal of Immunology 2016. [DOI: 10.4049/jimmunol.196.supp.124.34] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Abstract
Aspergillus fumigatus is a fungal pathogen causing severe and usually fatal invasive infections in immunocompromised patients. The Ficolins are pattern recognition molecules of the lectin pathway of complement and in vitro studies suggest a role for ficolins in the defence against A.fumigatus. However, little is known about their significance in fungal infections in vivo. Thus, our aim of the current project was to establish a murine model of pulmonary A. fumigatus infection to study the relevance of ficolins in host protection against A.fumigatus. Wildtype and ficolin knockout mice were infected intranasally with a sublethal dose of A.fumigatus conidia and the lungs were removed at various time points post-infection to assess the fungal load and expression of pro-inflammatory cytokines. In addition, the concentration of pro-inflammatory cytokines was measured in the bronchoalveolar lavage. After 24 hours of A.fumigatus infection, the pulmonary fungal load was significantly higher in ficolin knockout mice compared to wildtype mice. In contrast, no significant difference in fungal load between ficolin knockout mice and wildtype mice was observed after 12, 48 or 72 hours of infection. Interestingly, the increased fungal load in knockout mice 24 post-infection was accompanied by a significantly impaired induction of pro-inflammatory cytokines compared to wildtype mice. These results show that ficolins promote fungal clearance and modulate the pro-inflammatory cytokine response, demonstrating the importance of ficolins during the initial phase of A. fumigatus infections in vivo.
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Affiliation(s)
| | | | | | - Anne Rosbjerg
- 1Fac. of Hlth. and Med. Sci., Univ. of Copenhagen, Denmark
| | - Katrine Pilely
- 1Fac. of Hlth. and Med. Sci., Univ. of Copenhagen, Denmark
| | - Peter Garred
- 1Fac. of Hlth. and Med. Sci., Univ. of Copenhagen, Denmark
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Rosbjerg A, Genster N, Hansen KP, Skjoedt MO, Gal P, Stahl GL, Garred P. Mannose-binding lectin (MBL) is the main complement activator on Aspergillus fumigatus conidia under immunocompromised conditions. The Journal of Immunology 2016. [DOI: 10.4049/jimmunol.196.supp.63.6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
Aspergillus fumigatus is normally a non-pathogenic fungus, but in immunocompromised patients this fungus becomes highly pathogenic. Complement activation are thought to be of crucial importance for elimination of A. fumigatus. However, which of the three complement pathways that are important under immunocompromised conditions are only partly understood.
Conidia from a clinical isolate of A. fumigatus were co-incubated with serum before complement activation products C4b, C3b and TCC were measured in flow cytometry. Besides normal (NHS) and complement deficient sera plus complement inhibitors, we used umbilical cord serum (UCS) to mimic a compromised immune defense reflected in the low immunoglobulin (Ig) levels.
In NHS, the classical pathway was the dominant initiator with the alternative pathway providing a strong C3b amplification. Classical pathway is known to be initiated via C1q binding to Ig, whereas MBL and ficolin-2 from the lectin pathway bind the fungus directly. UCS conveyed low IgG and no IgM binding to the conidia, and we observed that complement activation on A. fumigatus in UCS was predominantly MBL dependent. UCS with low MBL had significantly lower C3b deposition than serum from NHS with low MBL. Moreover, a close positive correlation between MBL levels and C3b deposition in UCS (Spearman r = 0.79, p < 0.0001, n = 23) was observed. The significance of MBL was emphasized by decreased neutrophilic phagocytosis of conidia via MBL inhibition in C1q−/− serum.
We conclude that MBL is the main complement activator and phagocytosis initiator of A. fumigatus conidia in individuals with low Ig levels. This suggests a crucial role for the lectin pathway in protection against infection of A. fumigatus in immunocompromised patients.
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Affiliation(s)
- Anne Rosbjerg
- 1Fac. of Hlth. and Med. Sci., Univ. of Copenhagen, Denmark
| | | | | | | | - Peter Gal
- 2Hungarian Acad. of Sci., Budapest, Hungary
| | | | - Peter Garred
- 1Fac. of Hlth. and Med. Sci., Univ. of Copenhagen, Denmark
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Genster N, Takahashi M, Sekine H, Endo Y, Garred P, Fujita T. Lessons learned from mice deficient in lectin complement pathway molecules. Mol Immunol 2014; 61:59-68. [PMID: 25060538 DOI: 10.1016/j.molimm.2014.07.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Revised: 07/03/2014] [Accepted: 07/04/2014] [Indexed: 01/04/2023]
Abstract
The lectin pathway of the complement system is initiated when the pattern-recognition molecules, mannose-binding lectin (MBL), ficolins or collectin-11, bind to invading pathogens or damaged host cells. This leads to activation of MBL/ficolin/collectin-11 associated serine proteases (MASPs), which in turn activate downstream complement components, ultimately leading to elimination of the pathogen. Mice deficient in the key molecules of lectin pathway of complement have been generated in order to build knowledge of the molecular mechanisms of the lectin pathway in health and disease. Despite differences in the genetic arrangements of murine and human orthologues of lectin pathway molecules, the knockout mice have proven to be valuable models to explore the effect of deficiency states in humans. In addition, new insight and unexpected findings on the diverse roles of lectin pathway molecules in complement activation, pathogen infection, coagulation, host tissue injury and developmental biology have been revealed by in vivo investigations. This review provides an overview of the mice deficient in lectin pathway molecules and highlights some of the most important findings that have resulted from studies of these.
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Affiliation(s)
- Ninette Genster
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631 Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Minoru Takahashi
- Department of Immunology, Fukushima Medical University School of Medicine, Fukushima, Japan
| | - Hideharu Sekine
- Department of Immunology, Fukushima Medical University School of Medicine, Fukushima, Japan
| | - Yuichi Endo
- Radioisotope Center, Fukushima Medical University School of Medicine, Fukushima, Japan
| | - Peter Garred
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631 Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
| | - Teizo Fujita
- Fukushima General Hygiene Institute, Fukushima, Japan
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Genster N, Ma YJ, Munthe-Fog L, Garred P. The pattern recognition molecule ficolin-1 exhibits differential binding to lymphocyte subsets, providing a novel link between innate and adaptive immunity. Mol Immunol 2014; 57:181-90. [PMID: 24161415 DOI: 10.1016/j.molimm.2013.09.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Accepted: 09/28/2013] [Indexed: 10/26/2022]
Abstract
Ficolin-1 is a soluble pattern recognition molecule synthesized by myeloid cells and capable of activating the lectin pathway of complement on the surface of pathogens. It is tethered to the membranes of monocytes and granulocytes; however, the biological significance of cell-associated ficolin-1 is unknown. Recognition of healthy host cells by a pattern recognition molecule constitutes a potential hazard to self cells and tissues, emphasizing the importance of further elucidating the reported self-recognition. In the current study we investigated the potential recognition of lymphocytes by ficolin-1 and demonstrated that CD56(dim) NK-cells and both CD4(+) and CD8(+) subsets of activated T-cells were recognized by ficolin-1. In contrast we did not detect binding of ficolin-1 to CD56(bright) NK-cells, NKT-cells, resting T-cells or B-cells. Furthermore, we showed that the protein-lymphocyte interaction occurred via the pathogen-recognition domain of ficolin-1 to sialic acid on the cell surface. Thus, the differential binding of ficolin-1 to lymphocyte subsets suggests ficolin-1 as a novel link between innate and adaptive immunity. Our results provide new insight about the recognition properties of ficolin-1 and point toward additional immune modulating functions of the molecule besides its role in pathogen recognition.
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Affiliation(s)
- Ninette Genster
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631, Rigshospitalet, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
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Genster N, Ma Y, Munthe-Fog L, Garred P. The innate pathogen recognition molecule ficolin-1 exhibit differential binding to leukocyte subsets, providing a novel link between innate and adaptive immunity. Mol Immunol 2013. [DOI: 10.1016/j.molimm.2013.05.058] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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