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Peter Garred - One of the best experts on this subject based on the ideXlab platform.
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Circulating Ficolin-2 and Ficolin-3 Form Heterocomplexes.
Journal of immunology (Baltimore Md. : 1950), 2020Co-Authors: Ida Jarlhelt, Mikkel-ole Skjoedt, Katrine Pilely, Jytte Bryde Clausen, Rafael Bayarri-olmos, Peter GarredAbstract:The complement system constitutes an important part of the innate immune system. The collectins and the Ficolins are soluble pattern recognition molecules that contribute to complement activation via the lectin pathway. During previous experiments with Ficolin-2 and Ficolin-3, we have observed that the molecules may interact. We therefore hypothesized the existence of stable Ficolin-2/-3 heterocomplexes. We could demonstrate Ficolin-2/-3 heterocomplexes in normal human serum and plasma by ELISA using Abs specific for Ficolin-2 and Ficolin-3. The formation of heteromeric protein complexes were validated by coimmunoprecipitation and Western blot analysis. When recombinant Ficolin-2 and recombinant Ficolin-3 were mixed, no complexes were formed. However, when coexpressing Ficolin-2 and Ficolin-3 in Chinese hamster ovary cells, we could detect Ficolin-2/-3 heterocomplexes in the supernatant. Furthermore, we measured concentration of the Ficolin-2/-3 heterocomplexes in arbitrary units in 94 healthy individuals. We also established the relationship between the concentrations of Ficolin-2, Ficolin-3, and the Ficolin-2/-3 heterocomplexes. We observed that the concentration of the Ficolin-2/-3 heterocomplex correlated significantly with Ficolin-2 (ρ: 0.24, p < 0.018) and Ficolin-3 concentrations (ρ: 0.46, p < 0.0001). In conclusion, we describe a novel protein complex between Ficolin-2 and Ficolin-3 present in serum and plasma, which might be of additional biological relevance apart from the native Ficolin-2 and Ficolin-3 molecules.
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The Ficolin response to LPS challenge in mice.
Molecular immunology, 2019Co-Authors: Ida Jarlhelt, Ninette Genster, Nikolaj Kirketerp-møller, Mikkel-ole Skjoedt, Peter GarredAbstract: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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Ficolins do not alter host immune responses to lipopolysaccharide-induced inflammation in vivo.
Scientific reports, 2017Co-Authors: Ninette Genster, Jack Cowland, Olga Østrup, Camilla Schjalm, Tom Eirik Mollnes, Peter GarredAbstract: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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The Interaction Pattern of Murine Serum Ficolin-A with
2016Co-Authors: Tina Hummelshøj, Lea Munthe-fog, Yuichi Endo, Teizo Fujita, Ying Jie, Thomas Bjarnsholt, Claus Moser, Ole Skjoedt, Luigina Romani, Peter GarredAbstract:The Ficolins are soluble pattern recognition molecules in the lectin pathway of complement, but the spectrum and mode of interaction with pathogens are largely unknown. In this study, we investigated the binding properties of the murine serum Ficolin-A towards a panel of different clinical relevant microorganisms (N = 45) and compared the binding profile with human serum Ficolin-2 and Ficolin-3. Ficolin-A was able to bind Gram-positive bacteria strains including E. faecalis, L. monocytogenes and some S. aureus strains, but not to the investigated S. agalactiae (Group B streptococcus) strains. Regarding Gram-negative bacteria Ficolin-A was able to bind to some E. coli and P. aeruginosa strains, but not to the investigated Salmonella strains. Of particular interest Ficolin-A bound strongly to the pathogenic E. coli, O157:H7 and O149 strains, but it did not bind to the non-pathogenic E. coli, ATCC 25922 strain. Additionally, Ficolin-A was able to bind purified LPS from these pathogenic strains. Furthermore, Ficolin-A bound to a clinical isolate of the fungus A. fumigatus. In general Ficolin-2 showed similar selective binding spectrum towards pathogenic microorganisms as observed for Ficolin-A indicating specific pathophysiological roles of these molecules in host defence. In contrast, Ficolin-3 did not bind to any of th
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Alveolar recruitment of Ficolin-3 in response to acute pulmonary inflammation in humans
Immunobiology, 2016Co-Authors: Ronni R. Plovsing, Lea Munthe-fog, Ronan M. G. Berg, Lars Konge, Martin Iversen, Kirsten Møller, Peter GarredAbstract:Abstract Background Ficolins serve as soluble recognition molecules in the lectin pathway of complement. They are known to participate in the systemic host-response to infection but their role in local pulmonary defence is still incompletely understood. The purpose of this study was to clarify whether acute lung and systemic inflammation induce recruitment of lectins in humans. Methods Fifteen healthy volunteers received LPS intravenously (IV) or in a lung subsegment on two different occasions. Volunteers were evaluated by consecutive blood samples and by bronchoalveolar lavage 2, 4, 6, 8, or 24 h after LPS ( n = 3 in all groups), and gene expression patterns and protein levels of mannose-binding lectin (MBL) and Ficolins were determined. Results Endobronchial LPS was associated with an increase in alveolar Ficolin-3 and MBL levels ( p p p p p = 0.11) or plasma protein levels of MBL, Ficolin-2, or Ficolin-3. Conclusions LPS induces a tissue-specific recruitment of Ficolin-3 and Ficolin-1 in the lung and systemic compartment, respectively, suggesting an important role of distinct lectin complement pathway initiators in the local pulmonary and systemic host defence.
Teizo Fujita - One of the best experts on this subject based on the ideXlab platform.
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The Interaction Pattern of Murine Serum Ficolin-A with
2016Co-Authors: Tina Hummelshøj, Lea Munthe-fog, Yuichi Endo, Teizo Fujita, Ying Jie, Thomas Bjarnsholt, Claus Moser, Ole Skjoedt, Luigina Romani, Peter GarredAbstract:The Ficolins are soluble pattern recognition molecules in the lectin pathway of complement, but the spectrum and mode of interaction with pathogens are largely unknown. In this study, we investigated the binding properties of the murine serum Ficolin-A towards a panel of different clinical relevant microorganisms (N = 45) and compared the binding profile with human serum Ficolin-2 and Ficolin-3. Ficolin-A was able to bind Gram-positive bacteria strains including E. faecalis, L. monocytogenes and some S. aureus strains, but not to the investigated S. agalactiae (Group B streptococcus) strains. Regarding Gram-negative bacteria Ficolin-A was able to bind to some E. coli and P. aeruginosa strains, but not to the investigated Salmonella strains. Of particular interest Ficolin-A bound strongly to the pathogenic E. coli, O157:H7 and O149 strains, but it did not bind to the non-pathogenic E. coli, ATCC 25922 strain. Additionally, Ficolin-A was able to bind purified LPS from these pathogenic strains. Furthermore, Ficolin-A bound to a clinical isolate of the fungus A. fumigatus. In general Ficolin-2 showed similar selective binding spectrum towards pathogenic microorganisms as observed for Ficolin-A indicating specific pathophysiological roles of these molecules in host defence. In contrast, Ficolin-3 did not bind to any of th
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New insights into the role of Ficolins in the lectin pathway of innate immunity.
International review of cell and molecular biology, 2015Co-Authors: Yuichi Endo, Misao Matsushita, Teizo FujitaAbstract:In the innate immune system, a variety of recognition molecules provide the first-line host defense to prevent infection and maintain endogenous homeostasis. Ficolin is a soluble recognition molecule, which senses pathogen-associated molecular patterns on microbes and aberrant sugar structures on self-cells. It consists of a collagen-like stalk and a globular fibrinogen-like domain, the latter binding to carbohydrates such as N-acetylglucosamine. Ficolins have been widely identified in animals from higher invertebrates to mammals. In mammals, Ficolins form complexes with mannose-binding lectin-associated serine proteases (MASPs), and Ficolin-MASP complexes trigger complement activation via the lectin pathway. Once activated, complement mediates many immune responses including opsonization, phagocytosis, and cytokine production. Although the precise function of each Ficolin is still under investigation, accumulating information suggests that Ficolins have a crucial role in host defense by recognizing a variety of microorganisms and interacting with effector proteins.
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Purification, measurement of concentration, and functional complement assay of human Ficolins.
Methods in molecular biology (Clifton N.J.), 2013Co-Authors: Misao Matsushita, Yuichi Endo, Yu Liu, David C. Kilpatrick, Hiroshi Shiraki, Koichiro Tateishi, Mitsushi Tsujimura, Teizo FujitaAbstract:Ficolins constitute a group of lectins involved in innate immunity. L-Ficolin, H-Ficolin, and M-Ficolin are present in human serum. The human Ficolins differ in carbohydrate-binding specificity, but they have in common the ability to recognize the acetyl group. L-Ficolin and H-Ficolin are associated with serine proteases termed MASPs (MBL-associated serine proteases) and their truncated proteins, and the complexes (L/H-Ficolin-MASP) activate the lectin pathway of complement upon binding to their ligands. Recombinant M-Ficolin is also able to form a complex with MASP, resulting in complement activation. L-Ficolin and H-Ficolin can be purified as a complex with MASP from serum by utilizing their binding specificities. These Ficolin-MASP complexes have an ability to activate C4. Human Ficolins are quantified by ELISA using specific antibodies or ligands.
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Structural and Functional Overview of the Lectin Complement Pathway: Its Molecular Basis and Physiological Implication
Archivum Immunologiae et Therapiae Experimentalis, 2013Co-Authors: Misao Matsushita, Yuichi Endo, Teizo FujitaAbstract:The complement system is an effector mechanism in immunity. It is activated in three ways, the classical, alternative and lectin pathways. The lectin pathway is initiated by the binding of mannose-binding lectin (MBL) or Ficolins to carbohydrates on the surfaces of pathogens. In humans, MBL and three types of Ficolins (L-Ficolin, H-Ficolin, and M-Ficolin) are present in plasma. Of these lectins, at least, MBL, L-Ficolin, and H-Ficolin are complexed with three types of MBL-associated serine proteases (MASPs), MASP-1, MASP-2, and MASP-3 and their truncated proteins (MAp44 and sMAP). In the lectin pathway, the lectin–MASP complex (i.e., a complex of lectin, MASPs and their truncated proteins) binds to pathogens, resulting in the activation of C4 and C2 to generate a C3 convertase capable of activating C3. MASP-2 is involved in the activation of C4 and C2. MASP-1 activates C2 and MASP-2. The functions of MASP-3, sMAP, and MAp44 in the lectin pathway remain unknown. MASP-1 and MASP-3 also have a role in the alternative pathway. MBL and Ficolins are able to bind to a variety of pathogens depending on their carbohydrate binding specificity, resulting in the activation of the lectin pathway. Deficiencies of the components of the lectin pathway are associated to susceptibility to infection, indicating an important role of the lectin pathway in innate immunity. The lectin-MASP complex is also involved in innate immunity by activating the coagulation system. Recent findings suggest a crucial role of MASP-3 in development.
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The interaction pattern of murine serum Ficolin-A with microorganisms.
PloS one, 2012Co-Authors: Tina Hummelshøj, Lea Munthe-fog, Yuichi Endo, Teizo Fujita, Mikkel-ole Skjoedt, Ying Jie, Thomas Bjarnsholt, Claus Moser, Luigina Romani, Peter GarredAbstract:The Ficolins are soluble pattern recognition molecules in the lectin pathway of complement, but the spectrum and mode of interaction with pathogens are largely unknown. In this study, we investigated the binding properties of the murine serum Ficolin-A towards a panel of different clinical relevant microorganisms (N = 45) and compared the binding profile with human serum Ficolin-2 and Ficolin-3. Ficolin-A was able to bind Gram-positive bacteria strains including E. faecalis, L. monocytogenes and some S. aureus strains, but not to the investigated S. agalactiae (Group B streptococcus) strains. Regarding Gram-negative bacteria Ficolin-A was able to bind to some E. coli and P. aeruginosa strains, but not to the investigated Salmonella strains. Of particular interest Ficolin-A bound strongly to the pathogenic E. coli, O157:H7 and O149 strains, but it did not bind to the non-pathogenic E. coli, ATCC 25922 strain. Additionally, Ficolin-A was able to bind purified LPS from these pathogenic strains. Furthermore, Ficolin-A bound to a clinical isolate of the fungus A. fumigatus. In general Ficolin-2 showed similar selective binding spectrum towards pathogenic microorganisms as observed for Ficolin-A indicating specific pathophysiological roles of these molecules in host defence. In contrast, Ficolin-3 did not bind to any of the investigated microorganisms and the anti-microbial role of Ficolin-3 still remains elusive.
Misao Matsushita - One of the best experts on this subject based on the ideXlab platform.
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chapter 5 Ficolins
The Complement FactsBook (Second Edition), 2018Co-Authors: Misao MatsushitaAbstract:The human Ficolins are homooligomers. Each subunit is composed of an N-terminal region including two cysteine residues, a collagen-like domain, a neck region and a fibrinogen-like domain. Electron microscopy of the whole proteins of human Ficolin-2 and Ficolin-3 show bouquet-like images, similar to those first described for C1q. All human Ficolins recognise N-acetylated carbohydrates and compounds such as N-acetylglucosamine (GlcNAc) in common, although the spectrum of ligands for each Ficolin is slightly different. Human Ficolin-1 binds sialic acid, and human Ficolin-3 recognises d-fucose and galactose. Ficolin-2 exhibits broad binding specificities due to it having four distinct binding sites in the fibrinogen-like domain that allow it to bind various carbohydrates, including β-(1,3)-d-glucan and peptideglycan, and sulphated carbohydrates, including heparin, while Ficolin-1 and Ficolin-3 have only one binding site. In addition to carbohydrates, Ficolin-1 binds to tectonin9, and Ficolin-2 binds elastin, corticosteroid11 and DNA. Each Ficolin is able to bind to a spectrum of bacteria. Ficolin-1 and Ficolin-2 interact with C-reactive protein, boosting both the lectin and classical pathway. A low concentration of Ficolin-1 is also present in the serum with the mean level of 1 μg/mL. Ficolin-2 and Ficolin-3 are expressed in the liver and are secreted into the serum. Two cases of Ficolin-3 deficiency due to homozygosity for a FCN3 frameshift mutation (c.349delC, rs28357092) lacking the entire fibrinogen-like in exon 5 leading to the abnormal Ficolin-3 lacking the entire fibrinogen-like domain have been reported.
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Chapter 5 – Ficolins
The Complement FactsBook, 2018Co-Authors: Misao MatsushitaAbstract:The human Ficolins are homooligomers. Each subunit is composed of an N-terminal region including two cysteine residues, a collagen-like domain, a neck region and a fibrinogen-like domain. Electron microscopy of the whole proteins of human Ficolin-2 and Ficolin-3 show bouquet-like images, similar to those first described for C1q. All human Ficolins recognise N-acetylated carbohydrates and compounds such as N-acetylglucosamine (GlcNAc) in common, although the spectrum of ligands for each Ficolin is slightly different. Human Ficolin-1 binds sialic acid, and human Ficolin-3 recognises d-fucose and galactose. Ficolin-2 exhibits broad binding specificities due to it having four distinct binding sites in the fibrinogen-like domain that allow it to bind various carbohydrates, including β-(1,3)-d-glucan and peptideglycan, and sulphated carbohydrates, including heparin, while Ficolin-1 and Ficolin-3 have only one binding site. In addition to carbohydrates, Ficolin-1 binds to tectonin9, and Ficolin-2 binds elastin, corticosteroid11 and DNA. Each Ficolin is able to bind to a spectrum of bacteria. Ficolin-1 and Ficolin-2 interact with C-reactive protein, boosting both the lectin and classical pathway. A low concentration of Ficolin-1 is also present in the serum with the mean level of 1 μg/mL. Ficolin-2 and Ficolin-3 are expressed in the liver and are secreted into the serum. Two cases of Ficolin-3 deficiency due to homozygosity for a FCN3 frameshift mutation (c.349delC, rs28357092) lacking the entire fibrinogen-like in exon 5 leading to the abnormal Ficolin-3 lacking the entire fibrinogen-like domain have been reported.
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New insights into the role of Ficolins in the lectin pathway of innate immunity.
International review of cell and molecular biology, 2015Co-Authors: Yuichi Endo, Misao Matsushita, Teizo FujitaAbstract:In the innate immune system, a variety of recognition molecules provide the first-line host defense to prevent infection and maintain endogenous homeostasis. Ficolin is a soluble recognition molecule, which senses pathogen-associated molecular patterns on microbes and aberrant sugar structures on self-cells. It consists of a collagen-like stalk and a globular fibrinogen-like domain, the latter binding to carbohydrates such as N-acetylglucosamine. Ficolins have been widely identified in animals from higher invertebrates to mammals. In mammals, Ficolins form complexes with mannose-binding lectin-associated serine proteases (MASPs), and Ficolin-MASP complexes trigger complement activation via the lectin pathway. Once activated, complement mediates many immune responses including opsonization, phagocytosis, and cytokine production. Although the precise function of each Ficolin is still under investigation, accumulating information suggests that Ficolins have a crucial role in host defense by recognizing a variety of microorganisms and interacting with effector proteins.
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Serum Ficolin-2 in hospitalised patients with community-acquired pneumonia.
Inflammation, 2014Co-Authors: James D. Chalmers, Misao Matsushita, David C. Kilpatrick, Gilly B. Fleming, Julia Rutherford, Adam T. HillAbstract:Mannose binding lectin (MBL) and Ficolins contribute to host defence through activation of the lectin pathway of complement. In this study, serum levels of Ficolin-2 and MBL were determined in 276 patients with community-acquired pneumonia (CAP). MBL deficiency and Ficolin-2 insufficiency were defined using previously validated cut-offs. No differences were observed in MBL or Ficolin-2 between patients and controls. MBL-deficient patients (
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Purification, measurement of concentration, and functional complement assay of human Ficolins.
Methods in molecular biology (Clifton N.J.), 2013Co-Authors: Misao Matsushita, Yuichi Endo, Yu Liu, David C. Kilpatrick, Hiroshi Shiraki, Koichiro Tateishi, Mitsushi Tsujimura, Teizo FujitaAbstract:Ficolins constitute a group of lectins involved in innate immunity. L-Ficolin, H-Ficolin, and M-Ficolin are present in human serum. The human Ficolins differ in carbohydrate-binding specificity, but they have in common the ability to recognize the acetyl group. L-Ficolin and H-Ficolin are associated with serine proteases termed MASPs (MBL-associated serine proteases) and their truncated proteins, and the complexes (L/H-Ficolin-MASP) activate the lectin pathway of complement upon binding to their ligands. Recombinant M-Ficolin is also able to form a complex with MASP, resulting in complement activation. L-Ficolin and H-Ficolin can be purified as a complex with MASP from serum by utilizing their binding specificities. These Ficolin-MASP complexes have an ability to activate C4. Human Ficolins are quantified by ELISA using specific antibodies or ligands.
Yuichi Endo - One of the best experts on this subject based on the ideXlab platform.
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The Interaction Pattern of Murine Serum Ficolin-A with
2016Co-Authors: Tina Hummelshøj, Lea Munthe-fog, Yuichi Endo, Teizo Fujita, Ying Jie, Thomas Bjarnsholt, Claus Moser, Ole Skjoedt, Luigina Romani, Peter GarredAbstract:The Ficolins are soluble pattern recognition molecules in the lectin pathway of complement, but the spectrum and mode of interaction with pathogens are largely unknown. In this study, we investigated the binding properties of the murine serum Ficolin-A towards a panel of different clinical relevant microorganisms (N = 45) and compared the binding profile with human serum Ficolin-2 and Ficolin-3. Ficolin-A was able to bind Gram-positive bacteria strains including E. faecalis, L. monocytogenes and some S. aureus strains, but not to the investigated S. agalactiae (Group B streptococcus) strains. Regarding Gram-negative bacteria Ficolin-A was able to bind to some E. coli and P. aeruginosa strains, but not to the investigated Salmonella strains. Of particular interest Ficolin-A bound strongly to the pathogenic E. coli, O157:H7 and O149 strains, but it did not bind to the non-pathogenic E. coli, ATCC 25922 strain. Additionally, Ficolin-A was able to bind purified LPS from these pathogenic strains. Furthermore, Ficolin-A bound to a clinical isolate of the fungus A. fumigatus. In general Ficolin-2 showed similar selective binding spectrum towards pathogenic microorganisms as observed for Ficolin-A indicating specific pathophysiological roles of these molecules in host defence. In contrast, Ficolin-3 did not bind to any of th
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New insights into the role of Ficolins in the lectin pathway of innate immunity.
International review of cell and molecular biology, 2015Co-Authors: Yuichi Endo, Misao Matsushita, Teizo FujitaAbstract:In the innate immune system, a variety of recognition molecules provide the first-line host defense to prevent infection and maintain endogenous homeostasis. Ficolin is a soluble recognition molecule, which senses pathogen-associated molecular patterns on microbes and aberrant sugar structures on self-cells. It consists of a collagen-like stalk and a globular fibrinogen-like domain, the latter binding to carbohydrates such as N-acetylglucosamine. Ficolins have been widely identified in animals from higher invertebrates to mammals. In mammals, Ficolins form complexes with mannose-binding lectin-associated serine proteases (MASPs), and Ficolin-MASP complexes trigger complement activation via the lectin pathway. Once activated, complement mediates many immune responses including opsonization, phagocytosis, and cytokine production. Although the precise function of each Ficolin is still under investigation, accumulating information suggests that Ficolins have a crucial role in host defense by recognizing a variety of microorganisms and interacting with effector proteins.
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Purification, measurement of concentration, and functional complement assay of human Ficolins.
Methods in molecular biology (Clifton N.J.), 2013Co-Authors: Misao Matsushita, Yuichi Endo, Yu Liu, David C. Kilpatrick, Hiroshi Shiraki, Koichiro Tateishi, Mitsushi Tsujimura, Teizo FujitaAbstract:Ficolins constitute a group of lectins involved in innate immunity. L-Ficolin, H-Ficolin, and M-Ficolin are present in human serum. The human Ficolins differ in carbohydrate-binding specificity, but they have in common the ability to recognize the acetyl group. L-Ficolin and H-Ficolin are associated with serine proteases termed MASPs (MBL-associated serine proteases) and their truncated proteins, and the complexes (L/H-Ficolin-MASP) activate the lectin pathway of complement upon binding to their ligands. Recombinant M-Ficolin is also able to form a complex with MASP, resulting in complement activation. L-Ficolin and H-Ficolin can be purified as a complex with MASP from serum by utilizing their binding specificities. These Ficolin-MASP complexes have an ability to activate C4. Human Ficolins are quantified by ELISA using specific antibodies or ligands.
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Structural and Functional Overview of the Lectin Complement Pathway: Its Molecular Basis and Physiological Implication
Archivum Immunologiae et Therapiae Experimentalis, 2013Co-Authors: Misao Matsushita, Yuichi Endo, Teizo FujitaAbstract:The complement system is an effector mechanism in immunity. It is activated in three ways, the classical, alternative and lectin pathways. The lectin pathway is initiated by the binding of mannose-binding lectin (MBL) or Ficolins to carbohydrates on the surfaces of pathogens. In humans, MBL and three types of Ficolins (L-Ficolin, H-Ficolin, and M-Ficolin) are present in plasma. Of these lectins, at least, MBL, L-Ficolin, and H-Ficolin are complexed with three types of MBL-associated serine proteases (MASPs), MASP-1, MASP-2, and MASP-3 and their truncated proteins (MAp44 and sMAP). In the lectin pathway, the lectin–MASP complex (i.e., a complex of lectin, MASPs and their truncated proteins) binds to pathogens, resulting in the activation of C4 and C2 to generate a C3 convertase capable of activating C3. MASP-2 is involved in the activation of C4 and C2. MASP-1 activates C2 and MASP-2. The functions of MASP-3, sMAP, and MAp44 in the lectin pathway remain unknown. MASP-1 and MASP-3 also have a role in the alternative pathway. MBL and Ficolins are able to bind to a variety of pathogens depending on their carbohydrate binding specificity, resulting in the activation of the lectin pathway. Deficiencies of the components of the lectin pathway are associated to susceptibility to infection, indicating an important role of the lectin pathway in innate immunity. The lectin-MASP complex is also involved in innate immunity by activating the coagulation system. Recent findings suggest a crucial role of MASP-3 in development.
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mice deficient in Ficolin a lectin complement pathway recognition molecule are susceptible to streptococcus pneumoniae infection
Journal of Immunology, 2012Co-Authors: Yuichi Endo, Kazuko Kanno, Minoru Takahashi, Yu Liu, Naomi Nakazawa, Daisuke Iwaki, Yumi Ishida, Toshihisa Kodama, Tomohiro Matsuzaka, Kohsuke TsuchiyaAbstract:Mannose-binding lectin (MBL) and Ficolin are complexed with MBL-associated serine proteases, key enzymes of complement activation via the lectin pathway, and act as soluble pattern recognition molecules in the innate immune system. Although numerous reports have revealed the importance of MBL in infectious diseases and autoimmune disorders, the role of Ficolin is still unclear. To define the specific role of Ficolin in vivo, we generated model mice deficient in Ficolins. The Ficolin A (FcnA)–deficient ( Fcna −/− ) and FcnA/Ficolin B double-deficient ( Fcna −/− b −/− ) mice lacked FcnA-mediated complement activation in the sera, because of the absence of complexes comprising FcnA and MBL-associated serine proteases. When the host defense was evaluated by transnasal infection with a Streptococcus pneumoniae strain, which was recognized by Ficolins, but not by MBLs, the survival rate was significantly reduced in all three Ficolin-deficient ( Fcna −/− , Fcnb −/− , and Fcna −/− b −/− ) mice compared with wild-type mice. Reconstitution of the FcnA-mediated lectin pathway in vivo improved survival rate in Fcna −/− but not in Fcna −/− b −/− mice, suggesting that both FcnA and Ficolin B are essential in defense against S. pneumoniae . These results suggest that Ficolins play a crucial role in innate immunity against pneumococcal infection through the lectin complement pathway.
Tina Hummelshøj - One of the best experts on this subject based on the ideXlab platform.
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The Interaction Pattern of Murine Serum Ficolin-A with
2016Co-Authors: Tina Hummelshøj, Lea Munthe-fog, Yuichi Endo, Teizo Fujita, Ying Jie, Thomas Bjarnsholt, Claus Moser, Ole Skjoedt, Luigina Romani, Peter GarredAbstract:The Ficolins are soluble pattern recognition molecules in the lectin pathway of complement, but the spectrum and mode of interaction with pathogens are largely unknown. In this study, we investigated the binding properties of the murine serum Ficolin-A towards a panel of different clinical relevant microorganisms (N = 45) and compared the binding profile with human serum Ficolin-2 and Ficolin-3. Ficolin-A was able to bind Gram-positive bacteria strains including E. faecalis, L. monocytogenes and some S. aureus strains, but not to the investigated S. agalactiae (Group B streptococcus) strains. Regarding Gram-negative bacteria Ficolin-A was able to bind to some E. coli and P. aeruginosa strains, but not to the investigated Salmonella strains. Of particular interest Ficolin-A bound strongly to the pathogenic E. coli, O157:H7 and O149 strains, but it did not bind to the non-pathogenic E. coli, ATCC 25922 strain. Additionally, Ficolin-A was able to bind purified LPS from these pathogenic strains. Furthermore, Ficolin-A bound to a clinical isolate of the fungus A. fumigatus. In general Ficolin-2 showed similar selective binding spectrum towards pathogenic microorganisms as observed for Ficolin-A indicating specific pathophysiological roles of these molecules in host defence. In contrast, Ficolin-3 did not bind to any of th
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The interaction pattern of murine serum Ficolin-A with microorganisms.
PloS one, 2012Co-Authors: Tina Hummelshøj, Lea Munthe-fog, Yuichi Endo, Teizo Fujita, Mikkel-ole Skjoedt, Ying Jie, Thomas Bjarnsholt, Claus Moser, Luigina Romani, Peter GarredAbstract:The Ficolins are soluble pattern recognition molecules in the lectin pathway of complement, but the spectrum and mode of interaction with pathogens are largely unknown. In this study, we investigated the binding properties of the murine serum Ficolin-A towards a panel of different clinical relevant microorganisms (N = 45) and compared the binding profile with human serum Ficolin-2 and Ficolin-3. Ficolin-A was able to bind Gram-positive bacteria strains including E. faecalis, L. monocytogenes and some S. aureus strains, but not to the investigated S. agalactiae (Group B streptococcus) strains. Regarding Gram-negative bacteria Ficolin-A was able to bind to some E. coli and P. aeruginosa strains, but not to the investigated Salmonella strains. Of particular interest Ficolin-A bound strongly to the pathogenic E. coli, O157:H7 and O149 strains, but it did not bind to the non-pathogenic E. coli, ATCC 25922 strain. Additionally, Ficolin-A was able to bind purified LPS from these pathogenic strains. Furthermore, Ficolin-A bound to a clinical isolate of the fungus A. fumigatus. In general Ficolin-2 showed similar selective binding spectrum towards pathogenic microorganisms as observed for Ficolin-A indicating specific pathophysiological roles of these molecules in host defence. In contrast, Ficolin-3 did not bind to any of the investigated microorganisms and the anti-microbial role of Ficolin-3 still remains elusive.
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Allelic lineages of the Ficolin genes (FCNs) are passed from ancestral to descendant primates.
PloS one, 2011Co-Authors: Tina Hummelshøj, Lea Munthe-fog, Janna Nissen, Claus Koch, Mads F. Bertelsen, Peter GarredAbstract:The Ficolins recognize carbohydrates and acetylated compounds on microorganisms and dying host cells and are able to activate the lectin pathway of the complement system. In humans, three Ficolin genes have been identified: FCN1, FCN2 and FCN3, which encode Ficolin-1, Ficolin-2 and Ficolin-3, respectively. Rodents have only two Ficolins designated Ficolin-A and Ficolin-B that are closely related to human Ficolin-1, while the rodent FCN3 orthologue is a pseudogene. Ficolin-2 and Ficolin-3 have so far only been observed in humans. Thus, we performed a systematic investigation of the FCN genes in non-human primates. The exons and intron-exon boundaries of the FCN1-3 genes were sequenced in the following primate species: chimpanzee, gorilla, orangutan, rhesus macaque, cynomolgus macaque, baboon and common marmoset. We found that the exon organisation of the FCN genes was very similar between all the non-human primates and the human FCN genes. Several variations in the FCN genes were found in more than one primate specie suggesting that they were carried from one species to another including humans. The amino acid diversity of the Ficolins among human and non-human primate species was estimated by calculating the Shannon entropy revealing that all three proteins are generally highly conserved. Ficolin-1 and Ficolin-2 showed the highest diversity, whereas Ficolin-3 was more conserved. Ficolin-2 and Ficolin-3 were present in non-human primate sera with the same characteristic oligomeric structures as seen in human serum. Taken together all the FCN genes show the same characteristics in lower and higher primates. The existence of trans-species polymorphisms suggests that different FCN allelic lineages may be passed from ancestral to descendant species.
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Functional analysis of Ficolin-3 mediated complement activation.
PloS one, 2010Co-Authors: Estrid Hein, Tina Hummelshøj, Christian Honoré, Lea Munthe-fog, Mikkel-ole Skjoedt, Peter GarredAbstract:The recognition molecules of the lectin complement pathway are mannose-binding lectin and Ficolin -1, -2 and -3. Recently deficiency of Ficolin-3 was found to be associated with life threatening infections. Thus, we aimed to develop a functional method based on the ELISA platform for evaluating Ficolin-3 mediated complement activation that could be applicable for research and clinical use. Bovine serum albumin (BSA) was acetylated (acBSA) and chosen as a solid phase ligand for Ficolins in microtiter wells. Binding of Ficolins on acBSA was evaluated, as was functional complement activation assessed by C4, C3 and terminal complement complex (TCC) deposition. Serum Ficolin-3 bound to acBSA in a calcium dependent manner, while only minimal binding of Ficolin-2 and no binding of Ficolin-1 were observed. No binding to normal BSA was seen for any of the Ficolins. Serum C4, C3 and TCC deposition on acBSA were dependent only on Ficolin-3 in appropriate serum dilutions. Deposition of down stream complement components correlated highly significantly with the serum concentration of Ficolin-3 but not with Ficolin-2 in healthy donors. To make the assay robust for clinical use a chemical compound was applied to the samples that inhibited interference from the classical pathway due to the presence of anti-BSA antibodies in some sera. We describe a novel functional method for measuring complement activation mediated by Ficolin-3 in human serum up to the formation of TCC. The assay provides the possibility to diagnose functional and genetic defects of Ficolin-3 and down stream components in the lectin complement pathway.
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Tethering of Ficolin-1 to cell surfaces through recognition of sialic acid by the fibrinogen-like domain.
Journal of leukocyte biology, 2010Co-Authors: Christian Honoré, Tina Hummelshøj, Sara Rørvig, Niels Borregaard, Mikkel-ole Skjoedt, Peter GarredAbstract:Three Ficolins have been identified in humans: Ficolin-1 (M-Ficolin), Ficolin-2 (L-Ficolin), and Ficolin-3 (H-Ficolin). Ficolin-1 is the least-described of the Ficolins and is expressed by monocytes, granulocytes, and in the lungs. Ficolin-1 is found circulating at low concentrations in serum but is regarded primarily as a secretory molecule that exerts its function locally in inflamed tissues. Ficolin-1 has been reported on the surface of monocytes and granulocytes and was suggested originally to function as a phagocytic receptor. However, the molecule does not contain any obvious transmembrane domain, and no binding partners have been identified. To gain further insight in the physiological role of Ficolin-1, we sought to identify the molecular mechanism responsible for the membrane association of Ficolin-1 to monocytes and granulocytes. We demonstrate that expression of Ficolin-1 on the cell surface is restricted to monocytes and granulocytes. Ficolin-1 is tethered to the cell surface of these cells through its fibrinogen-like domain, and the ligand involved in the binding of Ficolin-1 is shown to be sialic acid. Moreover, rFicolin-1 bound activated but not resting T lymphocytes. Together, these results demonstrate a novel self-recognition mechanism of leukocytes mediated by the fibrinogen-like domain of Ficolin-1.