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Vasta GR, Amzel LM, Bianchet MA, Cammarata M, Feng C, Saito K. F-Type Lectins: A Highly Diversified Family of Fucose-Binding Proteins with a Unique Sequence Motif and Structural Fold, Involved in Self/Non-Self-Recognition. Front Immunol 2017; 8:1648. [PMID: 29238345 PMCID: PMC5712786 DOI: 10.3389/fimmu.2017.01648] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 11/10/2017] [Indexed: 12/25/2022] Open
Abstract
The F-type lectin (FTL) family is one of the most recent to be identified and structurally characterized. Members of the FTL family are characterized by a fucose recognition domain [F-type lectin domain (FTLD)] that displays a novel jellyroll fold ("F-type" fold) and unique carbohydrate- and calcium-binding sequence motifs. This novel lectin family comprises widely distributed proteins exhibiting single, double, or greater multiples of the FTLD, either tandemly arrayed or combined with other structurally and functionally distinct domains, yielding lectin subunits of pleiotropic properties even within a single species. Furthermore, the extraordinary variability of FTL sequences (isoforms) that are expressed in a single individual has revealed genetic mechanisms of diversification in ligand recognition that are unique to FTLs. Functions of FTLs in self/non-self-recognition include innate immunity, fertilization, microbial adhesion, and pathogenesis, among others. In addition, although the F-type fold is distinctive for FTLs, a structure-based search revealed apparently unrelated proteins with minor sequence similarity to FTLs that displayed the FTLD fold. In general, the phylogenetic analysis of FTLD sequences from viruses to mammals reveals clades that are consistent with the currently accepted taxonomy of extant species. However, the surprisingly discontinuous distribution of FTLDs within each taxonomic category suggests not only an extensive structural/functional diversification of the FTLs along evolutionary lineages but also that this intriguing lectin family has been subject to frequent gene duplication, secondary loss, lateral transfer, and functional co-option.
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Affiliation(s)
- Gerardo R. Vasta
- Department of Microbiology and Immunology, Institute of Marine and Environmental Technology, University of Maryland School of Medicine, University of Maryland, Baltimore, Baltimore, MD, United States
| | - L. Mario Amzel
- Department of Biophysics and Biophysical Chemistry, School of Medicine, Johns Hopkins University, Baltimore, MD, United States
| | - Mario A. Bianchet
- Department of Biophysics and Biophysical Chemistry, School of Medicine, Johns Hopkins University, Baltimore, MD, United States
- Department of Neurology, School of Medicine, Johns Hopkins University, Baltimore, MD, United States
| | - Matteo Cammarata
- Department of Earth and Marine Sciences, University of Palermo, Palermo, Italy
| | - Chiguang Feng
- Department of Microbiology and Immunology, Institute of Marine and Environmental Technology, University of Maryland School of Medicine, University of Maryland, Baltimore, Baltimore, MD, United States
| | - Keiko Saito
- Department of Marine Biotechnology, Institute of Marine and Environmental Technology, University of Maryland Baltimore County, Baltimore, MD, United States
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Endo Y, Matsushita M, Fujita T. New insights into the role of ficolins in the lectin pathway of innate immunity. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2015; 316:49-110. [PMID: 25805122 DOI: 10.1016/bs.ircmb.2015.01.003] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
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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Affiliation(s)
- Yuichi Endo
- Department of Immunology, Fukushima Medical University School of Medicine, Fukushima, Japan; Radioisotope Research Center, Fukushima Medical University School of Medicine, Fukushima, Japan
| | - Misao Matsushita
- Department of Applied Biochemistry, Tokai University, Kanagawa, Japan
| | - Teizo Fujita
- Department of Immunology, Fukushima Medical University School of Medicine, Fukushima, Japan; Fukushima General Hygiene Institute, Fukushima, Japan
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Xiang Z, Qu F, Wang F, Li J, Zhang Y, Yu Z. Characteristic and functional analysis of a ficolin-like protein from the oyster Crassostrea hongkongensis. FISH & SHELLFISH IMMUNOLOGY 2014; 40:514-23. [PMID: 25120216 DOI: 10.1016/j.fsi.2014.08.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Revised: 08/02/2014] [Accepted: 08/03/2014] [Indexed: 06/03/2023]
Abstract
Ficolins are a group of soluble animal proteins with multiple roles in innate immunity. These proteins recognize and bind carbohydrates in pathogens and activate the complement system, leading to opsonization, leukocyte activation, and direct pathogen killing, which have been reported in many animal species but might not be present in the shellfish lineage. In the present study, we identified the first fibrinogen-related protein from the oyster, Crassostrea hongkongensis. This novel ficolin-like protein contains a typical signal peptide and a fibrinogen-related domain (designated ChFCN) at the N and C termini, respectively, but does not contain the additional collagen-like domain of ficolins. The full-length cDNA of ChFCN is 1105 bp, encoding a putative protein of 297 amino acids with the molecular weight of 35.5 kD. ChFCN is ubiquitously expressed in selected tissues, with the highest expression level observed in the gills. The temporal expression of ChFCN following microbe infection shows that the expression of ChFCN in hemocytes increases at 3 h post-challenge. The ChFCN protein expression was also examined, and fluorescence microscopy revealed that deChFCN (truncated signal peptide) is located in the cytoplasm of HeLa cells. Full-length ChFCN was detected in the medium supernatant by western blot analysis. Recombinant ChFCN proteins with the molecular weight about 50 kD bind Saccharomyces cerevisiae, Staphylococcus haemolyticus or Escherichia coli K-12, but not those from Vibrio alginolyticus. Furthermore, the rChFCN protein could agglutinate Gram-negative bacteria E. coli K-12 and enhance the phagocytosis of C. hongkongensis hemocytes in vitro. These results indicate that ChFCN might play an important role in the immunity response of oysters.
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Affiliation(s)
- Zhiming Xiang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, China
| | - Fufa Qu
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, China; University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China
| | - Fuxuan Wang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, China; University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China
| | - Jun Li
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, China; University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China
| | - Yuehuan Zhang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, China
| | - Ziniu Yu
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, China.
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4
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Prasopdee S, Sotillo J, Tesana S, Laha T, Kulsantiwong J, Nolan MJ, Loukas A, Cantacessi C. RNA-Seq reveals infection-induced gene expression changes in the snail intermediate host of the carcinogenic liver fluke, Opisthorchis viverrini. PLoS Negl Trop Dis 2014; 8:e2765. [PMID: 24676090 PMCID: PMC3967946 DOI: 10.1371/journal.pntd.0002765] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Accepted: 02/16/2014] [Indexed: 01/29/2023] Open
Abstract
Background Bithynia siamensis goniomphalos is the snail intermediate host of the liver fluke, Opisthorchis viverrini, the leading cause of cholangiocarcinoma (CCA) in the Greater Mekong sub-region of Thailand. Despite the severe public health impact of Opisthorchis-induced CCA, knowledge of the molecular interactions occurring between the parasite and its snail intermediate host is scant. The examination of differences in gene expression profiling between uninfected and O. viverrini-infected B. siamensis goniomphalos could provide clues on fundamental pathways involved in the regulation of snail-parasite interplay. Methodology/Principal Findings Using high-throughput (Illumina) sequencing and extensive bioinformatic analyses, we characterized the transcriptomes of uninfected and O. viverrini-infected B. siamensis goniomphalos. Comparative analyses of gene expression profiling allowed the identification of 7,655 differentially expressed genes (DEGs), associated to 43 distinct biological pathways, including pathways associated with immune defense mechanisms against parasites. Amongst the DEGs with immune functions, transcripts encoding distinct proteases displayed the highest down-regulation in Bithynia specimens infected by O. viverrini; conversely, transcription of genes encoding heat-shock proteins and actins was significantly up-regulated in parasite-infected snails when compared to the uninfected counterparts. Conclusions/Significance The present study lays the foundation for functional studies of genes and gene products potentially involved in immune-molecular mechanisms implicated in the ability of the parasite to successfully colonize its snail intermediate host. The annotated dataset provided herein represents a ready-to-use molecular resource for the discovery of molecular pathways underlying susceptibility and resistance mechanisms of B. siamensis goniomphalos to O. viverrini and for comparative analyses with pulmonate snail intermediate hosts of other platyhelminths including schistosomes. Despite recent significant advances in knowledge of the fundamental biology of the carcinogenic liver fluke Opisthorchis viverrini, little is known of the complement of molecular interactions occurring between this parasite and its prosobranch snail intermediate host, Bithynia siamensis goniomphalos. The determination of such interactions is a key, necessary component of the development of future integrated control strategies for liver fluke infection and associated bile duct cancer. Here, we use cutting-edge high-throughput sequencing technologies and advanced bioinformatic analyses to characterize, for the first time, qualitative and quantitative differences in gene expression between uninfected and O. viverrini-infected B. siamensis goniomphalos collected from an endemic region of Northeast Thailand. The analyses led to the identification of a number of molecules putatively involved in immune defense pathways against invading O. viverrini, and of key biological mechanisms potentially implicated in the ability of the parasite to successfully colonize its snail intermediate host. We believe that this ready-to-use molecular resource will provide the scientific community with new tools for the development of strategies to control the spread of liver fluke infection and the resulting bile duct cancer.
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Affiliation(s)
- Sattrachai Prasopdee
- Food-borne Parasite Research Group, Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
- Centre for Biodiscovery and Molecular Development of Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Queensland, Australia
| | - Javier Sotillo
- Centre for Biodiscovery and Molecular Development of Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Queensland, Australia
| | - Smarn Tesana
- Food-borne Parasite Research Group, Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Thewarach Laha
- Food-borne Parasite Research Group, Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Jutharat Kulsantiwong
- Department of Biology, Faculty of Science, Udon Thani Rajabhat University, Udon Thani, Thailand
| | - Matthew J. Nolan
- Centre for Biodiscovery and Molecular Development of Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Queensland, Australia
| | - Alex Loukas
- Centre for Biodiscovery and Molecular Development of Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Queensland, Australia
| | - Cinzia Cantacessi
- Centre for Biodiscovery and Molecular Development of Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Queensland, Australia
- Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom
- * E-mail:
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Boldt ABW, Goeldner I, de Messias-Reason IJT. Relevance of the lectin pathway of complement in rheumatic diseases. Adv Clin Chem 2012; 56:105-53. [PMID: 22397030 DOI: 10.1016/b978-0-12-394317-0.00012-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Due to its importance both in the clearance of pathogens that contribute as rheumatic etiological agents and in the disposal of apoptotic bodies and potential autoimmune initiators, deficiencies of the components of the lectin pathway of complement have been found to increase susceptibility and modulate the severity of most rheumatic disorders. This chapter introduces the general aspects of the structure, function, and genetics of lectin pathway components and summarizes current knowledge of the field regarding rheumatic diseases predisposition and modulation.
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Affiliation(s)
- Angelica B W Boldt
- Molecular Immunopathology Laboratory, Department of Medical Pathology, Federal University of Paraná, Curitiba, Brazil
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6
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Endo Y, Matsushita M, Fujita T. The role of ficolins in the lectin pathway of innate immunity. Int J Biochem Cell Biol 2011; 43:705-12. [PMID: 21315829 DOI: 10.1016/j.biocel.2011.02.003] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2010] [Revised: 02/03/2011] [Accepted: 02/04/2011] [Indexed: 11/29/2022]
Abstract
Ficolins are a family of oligomeric proteins consisting of an N-terminal collagen-like domain and a C-terminal globular fibrinogen-like domain. They are novel lectins that employ the fibrinogen-like domain as a functional domain. Ficolins specifically recognize N-acetyl compounds such as N-acetylglucosamine, components of bacterial and fungal cell walls, and certain bacteria. Like mannose-binding lectin (MBL), ficolins circulate in complexes with MBL-associated serine proteases (MASPs). MASP complexes form with ficolins and MBL, thereby activating the complement through the lectin pathway. Upon binding of ficolins and MBL to carbohydrates on pathogens, MASPs convert to active forms, and subsequently activate the complement. The activated complements lead to pathogen phagocytosis, aggregation and lysis. In humans, three ficolins (L-, M- and H-ficolins) have been identified, which exhibit differences in tissue expression, protein location site, ligand-binding and bacteria-recognition, suggesting a specific role of each ficolin. In addition, these ficolins form complexes with three MASPs (MASP-1, MASP-2 and MASP-3) and two nonenzymatic proteins (sMAP and MAP-1), suggesting a highly sophisticated organization and regulated activation of the ficolin-dependent lectin pathway. This review provides an overview of our current knowledge of ficolins, especially human ficolins and their mouse homologues. We also discuss their possible physiological roles in innate immunity, especially their defensive role against bacterial infection.
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Affiliation(s)
- Yuichi Endo
- Department of Immunology, Fukushima Medical University School of Medicine, 1-Hikarigaoka, Fukushima 960-1295, Japan.
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7
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Romero A, Dios S, Poisa-Beiro L, Costa MM, Posada D, Figueras A, Novoa B. Individual sequence variability and functional activities of fibrinogen-related proteins (FREPs) in the Mediterranean mussel (Mytilus galloprovincialis) suggest ancient and complex immune recognition models in invertebrates. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2011; 35:334-344. [PMID: 21034769 DOI: 10.1016/j.dci.2010.10.007] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Revised: 10/19/2010] [Accepted: 10/19/2010] [Indexed: 05/30/2023]
Abstract
In this paper, we describe sequences of fibrinogen-related proteins (FREPs) in the Mediterranean mussel Mytilus galloprovincialis (MuFREPs) with the fibrinogen domain probably involved in the antigen recognition, but without the additional collagen-like domain of ficolins, molecules responsible for complement activation by the lectin pathway. Although they do not seem to be true or primive ficolins since the phylogenetic analysis are not conclusive enough, their expression is increased after bacterial infection or PAMPs treatment and they present opsonic activities similar to mammalian ficolins. The most remarkable aspect of these sequences was the existence of a very diverse set of FREP sequences among and within individuals (different mussels do not share any identical sequence) which parallels the extraordinary complexity of the immune system, suggesting the existence of a primitive system with a potential capacity to recognize and eliminate different kind of pathogens.
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Affiliation(s)
- Alejandro Romero
- Instituto de Investigaciones Marinas, Consejo Superior de Investigaciones Científicas (CSIC), Eduardo Cabello 6, 36208, Vigo, Spain
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8
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Rørvig S, Honore C, Larsson LI, Ohlsson S, Pedersen CC, Jacobsen LC, Cowland JB, Garred P, Borregaard N. Ficolin-1 is present in a highly mobilizable subset of human neutrophil granules and associates with the cell surface after stimulation with fMLP. J Leukoc Biol 2009; 86:1439-49. [PMID: 19741154 DOI: 10.1189/jlb.1008606] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Ficolins are soluble molecules that bind carbohydrate present on the surface of microorganisms and function as recognition molecules in the lectin complement pathway. Three ficolins have been identified in humans: ficolin-1, ficolin-2, and ficolin-3. Ficolin-1 is synthesized in monocytes and type II alveolar epithelial cells. Ficolin-1 has been shown to be present in secretory granules of human neutrophils, but it is not known which subset of the neutrophils' secretory granules harbors ficolin-1. To determine the exact subcellular localization of ficolin-1 in neutrophils, recombinant ficolin-1 was expressed in Chinese hamster ovary cells and used for generation of polyclonal antibodies. This allowed detection of ficolin-1 in subcellular fractions of human neutrophils by ELISA, by Western blotting, and by immunohistochemistry. Real-time PCR examination of normal human bone marrow showed FCN1 gene expression largely in myelocytes, metamyelocytes, and band cells with a profile quite similar to that of gelatinase. In accordance with this, biosynthesis studies of neutrophils precursor cells showed that ficolin-1 was primarily synthesized in myelocytes, metamyelocytes, and band cells. Immunohistochemistry and subcellular fractionation demonstrated that ficolin-1 is primarily localized in gelatinase granules but also in highly exocytosable gelatinase-poor granules, not described previously. Ficolin-1 is released from neutrophil granules by stimulation with fMLP or PMA, and the majority becomes associated with the surface membrane of the cells and can be detected by flow cytometry. Our studies show that neutrophils are a major source of ficolin-1, which can be readily exocytosed by stimulation.
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Affiliation(s)
- Sara Rørvig
- The Granulocyte Research Laboratory, Department of Hematology, Faculty of Life Sciences, University of Copenhagen, Copenhagen, Denmark.
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Thiel S, Gadjeva M. Humoral pattern recognition molecules: mannan-binding lectin and ficolins. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2009; 653:58-73. [PMID: 19799112 DOI: 10.1007/978-1-4419-0901-5_5] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Innate immunity comprises a sophisticated network of molecules, which recognize pathogens, and effector molecules, working together to establish a quick and efficient immune response to infectious agents. Complement activation triggered by mannan binding lectin (MBL) or ficolins represents a beautiful example of this network Both MBL and ficolins recognize specific chemical structures on the surface of antigens and pathogens, thus bind to a broad variety of pathogens. Once bound further complement deposition is achieved through a cascade of proteolytic reactions. MBL and ficolin induced complement activation is critical for adequate anti-bacterial, anti-fungal and anti-viral responses. This is well illustrated by numerous and convincing studies that demonstrate associations between MBL deficiency and infections. Recent work has also highlighted that MBL and ficolins recognize self-structures, thus extending the role of these molecules beyond the traditional view of first line defense molecules. It appears that MBL deficiency may modulate the prognosis of inflammatory and autoimmune diseases. What is known about the mechanisms behind this broad scope of activities of MBL and ficolins is discussed in this chapter.
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Affiliation(s)
- Steffen Thiel
- Department of Medical Microbiology and Immunology, University of Aarhus, Aarhus, Denmark
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Teillet F, Gaboriaud C, Lacroix M, Martin L, Arlaud GJ, Thielens NM. Crystal structure of the CUB1-EGF-CUB2 domain of human MASP-1/3 and identification of its interaction sites with mannan-binding lectin and ficolins. J Biol Chem 2008; 283:25715-25724. [PMID: 18596036 DOI: 10.1074/jbc.m803551200] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
MASP-1 and MASP-3 are homologous proteases arising from alternative splicing of the MASP1/3 gene. They include an identical CUB(1)-EGF-CUB(2)-CCP(1)-CCP(2) module array prolonged by different serine protease domains at the C-terminal end. The x-ray structure of the CUB(1)-EGF-CUB(2) domain of human MASP-1/3, responsible for interaction of MASP-1 and -3 with their partner proteins mannan-binding lectin (MBL) and ficolins, was solved to a resolution of 2.3A(.) The structure shows a head-to-tail homodimer mainly stabilized by hydrophobic interactions between the CUB(1) module of one monomer and the epidermal growth factor (EGF) module of its counterpart. A Ca(2+) ion bound primarily to both EGF modules stabilizes the intra- and inter-monomer CUB(1)-EGF interfaces. Additional Ca(2+) ions are bound to each CUB(1) and CUB(2) module through six ligands contributed by Glu(49), Asp(57), Asp(102), and Ser(104) (CUB(1)) and their counterparts Glu(216), Asp(226), Asp(263), and Ser(265) (CUB(2)), plus one and two water molecules, respectively. To identify the residues involved in interaction of MASP-1 and -3 with MBL and L- and H-ficolins, 27 point mutants of human MASP-3 were generated, and their binding properties were analyzed using surface plasmon resonance spectroscopy. These mutations map two homologous binding sites contributed by modules CUB(1) and CUB(2), located in close vicinity of their Ca(2+)-binding sites and stabilized by the Ca(2+) ion. This information allows us to propose a model of the MBL-MASP-1/3 interaction, involving a major electrostatic interaction between two acidic Ca(2+) ligands of MASP-1/3 and a conserved lysine of MBL. Based on these and other data, a schematic model of a MBL.MASP complex is proposed.
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Affiliation(s)
- Florence Teillet
- Laboratoire d'Enzymologie Moléculaire, 38027 Grenoble Cedex 1, France
| | - Christine Gaboriaud
- Laboratoire de Cristallographie et Cristallogenèse des Protéines, Institut de Biologie Structurale Jean-Pierre Ebel, CNRS-CEA-UJF, UMR 5075, 41 Rue Jules Horowitz, 38027 Grenoble Cedex 1, France
| | - Monique Lacroix
- Laboratoire d'Enzymologie Moléculaire, 38027 Grenoble Cedex 1, France
| | - Lydie Martin
- Laboratoire de Cristallographie et Cristallogenèse des Protéines, Institut de Biologie Structurale Jean-Pierre Ebel, CNRS-CEA-UJF, UMR 5075, 41 Rue Jules Horowitz, 38027 Grenoble Cedex 1, France
| | - Gérard J Arlaud
- Laboratoire d'Enzymologie Moléculaire, 38027 Grenoble Cedex 1, France
| | - Nicole M Thielens
- Laboratoire d'Enzymologie Moléculaire, 38027 Grenoble Cedex 1, France.
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Keirstead ND, Lee C, Yoo D, Brooks AS, Hayes MA. Porcine plasma ficolin binds and reduces infectivity of porcine reproductive and respiratory syndrome virus (PRRSV) in vitro. Antiviral Res 2008; 77:28-38. [PMID: 17850894 PMCID: PMC7172368 DOI: 10.1016/j.antiviral.2007.08.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2007] [Revised: 07/28/2007] [Accepted: 08/01/2007] [Indexed: 12/27/2022]
Abstract
Ficolins are collagenous lectins that bind N-acetylated glycans and participate in innate immune responses, including phagocytosis and complement activation. Related collagenous lectins such as mannan binding lectin (MBL) and surfactant proteins A and D possess antiviral activity, but this activity has not been demonstrated for ficolins. In these studies, we used purified porcine plasma ficolin alpha and recombinant ficolin alpha to assess their ability to bind and neutralize porcine reproductive and respiratory virus (PRRSV) in various assays. Recombinant ficolin alpha was designed with a C-terminal 6-histidine tag using a pcDNA3.1 expression vector system in CHO K1 cells. Plasma-purified and recombinant ficolin alpha reduced cytopathic effect of PRRSV-infected Marc-145 cells in neutralization assays and inhibited replication of infectious viral particles in a GlcNAc-dependent manner. In vitro replication determined by plaque assay was inhibited in the presence of plasma-purified ficolin alpha and recombinant ficolin. Immunoreactive plasma ficolin alpha and recombinant ficolin alpha also bound PRRSV-coated wells in a GlcNAc-dependent manner. These studies indicate that porcine ficolin can bind and neutralize a common arterivirus that is a major pathogen of swine.
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Key Words
- anova, analysis of variance
- cho k1 cells, chinese hamster ovary k1 cell line
- cpe, cytopathic effect
- elisa, enzyme-linked immunosorbent assay
- glcnac, n-acetyl-d-glucosamine
- kda, kilodaltons
- mbl, mannan binding lectin
- maldi, matrix-assisted laser desorption/ionization
- marc-145 cells, african monkey kidney cell line
- ms/ms, tandem mass spectrometry
- pfu, plaque-forming units
- pfcn, plasma ficolin α
- pi, isoelectric point
- plsd, protected least significant difference
- prrsv, porcine reproductive and respiratory syndrome virus
- rfcn, recombinant ficolin
- sds-page, sodium dilauryl sulfate-polyacrylamide gel electrophoresis
- ficolins
- mannan binding lectins
- innate immunity
- pigs
- n-acetylglucosamine
- prrsv
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Garlatti V, Martin L, Gout E, Reiser JB, Fujita T, Arlaud GJ, Thielens NM, Gaboriaud C. Structural basis for innate immune sensing by M-ficolin and its control by a pH-dependent conformational switch. J Biol Chem 2007; 282:35814-20. [PMID: 17897951 DOI: 10.1074/jbc.m705741200] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Ficolins are soluble oligomeric proteins with lectin-like activity, assembled from collagen fibers prolonged by fibrinogen-like recognition domains. They act as innate immune sensors by recognizing conserved molecular markers exposed on microbial surfaces and thereby triggering effector mechanisms such as enhanced phagocytosis and inflammation. In humans, L- and H-ficolins have been characterized in plasma, whereas a third species, M-ficolin, is secreted by monocytes and macrophages. To decipher the molecular mechanisms underlying their recognition properties, we previously solved the structures of the recognition domains of L- and H-ficolins, in complex with various model ligands (Garlatti, V., Belloy, N., Martin, L., Lacroix, M., Matsushita, M., Endo, Y., Fujita, T., Fontecilla-Camps, J. C., Arlaud, G. J., Thielens, N. M., and Gaboriaud, C. (2007) EMBO J. 24, 623-633). We now report the ligand-bound crystal structures of the recognition domain of M-ficolin, determined at high resolution (1.75-1.8 A), which provides the first structural insights into its binding properties. Interaction with acetylated carbohydrates differs from the one previously described for L-ficolin. This study also reveals the structural determinants for binding to sialylated compounds, a property restricted to human M-ficolin and its mouse counterpart, ficolin B. Finally, comparison between the ligand-bound structures obtained at neutral pH and nonbinding conformations observed at pH 5.6 reveals how the ligand binding site is dislocated at acidic pH. This means that the binding function of M-ficolin is subject to a pH-sensitive conformational switch. Considering that the homologous ficolin B is found in the lysosomes of activated macrophages (Runza, V. L., Hehlgans, T., Echtenacher, B., Zahringer, U., Schwaeble, W. J., and Mannel, D. N. (2006) J. Endotoxin Res. 12, 120-126), we propose that this switch could play a physiological role in such acidic compartments.
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Affiliation(s)
- Virginie Garlatti
- Laboratoire de Cristallographie et Cristallogénèse des Protéines, Institut de Biologie Structurale Jean-Pierre Ebel, Commissariat à l'Energie Atomique-CNRS-Université Joseph Fourier, 38027 Grenoble, France
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