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Haji S, Ito T, Guenther C, Nakano M, Shimizu T, Mori D, Chiba Y, Tanaka M, Mishra SK, Willment JA, Brown GD, Nagae M, Yamasaki S. Human Dectin-1 is O-glycosylated and serves as a ligand for C-type lectin receptor CLEC-2. eLife 2022; 11:83037. [PMID: 36479973 PMCID: PMC9788829 DOI: 10.7554/elife.83037] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Accepted: 12/07/2022] [Indexed: 12/13/2022] Open
Abstract
C-type lectin receptors (CLRs) elicit immune responses upon recognition of glycoconjugates present on pathogens and self-components. While Dectin-1 is the best-characterized CLR recognizing β-glucan on pathogens, the endogenous targets of Dectin-1 are not fully understood. Herein, we report that human Dectin-1 is a ligand for CLEC-2, another CLR expressed on platelets. Biochemical analyses revealed that Dectin-1 is a mucin-like protein as its stalk region is highly O-glycosylated. A sialylated core 1 glycan attached to the EDxxT motif of human Dectin-1, which is absent in mouse Dectin-1, provides a ligand moiety for CLEC-2. Strikingly, the expression of human Dectin-1 in mice rescued the lethality and lymphatic defect resulting from a deficiency of Podoplanin, a known CLEC-2 ligand. This finding is the first example of an innate immune receptor also functioning as a physiological ligand to regulate ontogeny upon glycosylation.
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Affiliation(s)
- Shojiro Haji
- Department of Molecular Immunology, Research Institute for Microbial Diseases, Osaka UniversityOsakaJapan,Laboratory of Molecular Immunology, Immunology Frontier Research Center (IFReC), Osaka UniversityOsakaJapan
| | - Taiki Ito
- Department of Molecular Immunology, Research Institute for Microbial Diseases, Osaka UniversityOsakaJapan,Laboratory of Molecular Immunology, Immunology Frontier Research Center (IFReC), Osaka UniversityOsakaJapan
| | - Carla Guenther
- Department of Molecular Immunology, Research Institute for Microbial Diseases, Osaka UniversityOsakaJapan,Laboratory of Molecular Immunology, Immunology Frontier Research Center (IFReC), Osaka UniversityOsakaJapan
| | - Miyako Nakano
- Graduate School of Integrated Sciences for Life, Hiroshima UniversityHiroshimaJapan
| | - Takashi Shimizu
- Department of Molecular Immunology, Research Institute for Microbial Diseases, Osaka UniversityOsakaJapan,Laboratory of Molecular Immunology, Immunology Frontier Research Center (IFReC), Osaka UniversityOsakaJapan
| | - Daiki Mori
- Department of Molecular Immunology, Research Institute for Microbial Diseases, Osaka UniversityOsakaJapan,Laboratory of Molecular Immunology, Immunology Frontier Research Center (IFReC), Osaka UniversityOsakaJapan
| | - Yasunori Chiba
- Cellular and Molecular Biotechnology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST)TsukubaJapan
| | - Masato Tanaka
- Laboratory of Immune Regulation School of Life Sciences, Tokyo University of Pharmacy and Life SciencesHachiojiJapan
| | - Sushil K Mishra
- The Glycoscience Group, National University of Ireland, GalwayGalwayIreland
| | - Janet A Willment
- Medical Research Council Centre for Medical Mycology, University of ExeterExeterUnited Kingdom
| | - Gordon D Brown
- Medical Research Council Centre for Medical Mycology, University of ExeterExeterUnited Kingdom
| | - Masamichi Nagae
- Department of Molecular Immunology, Research Institute for Microbial Diseases, Osaka UniversityOsakaJapan,Laboratory of Molecular Immunology, Immunology Frontier Research Center (IFReC), Osaka UniversityOsakaJapan
| | - Sho Yamasaki
- Department of Molecular Immunology, Research Institute for Microbial Diseases, Osaka UniversityOsakaJapan,Laboratory of Molecular Immunology, Immunology Frontier Research Center (IFReC), Osaka UniversityOsakaJapan,Center for Infectious Disease Education and Research (CiDER), Osaka UniversityOsakaJapan,Division of Molecular Design, Research Center for Systems Immunology, Medical Institute of Bioregulation, Kyushu UniversityFukuokaJapan
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2
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Watson A, Sørensen GL, Holmskov U, Whitwell HJ, Madsen J, Clark H. Generation of novel trimeric fragments of human SP-A and SP-D after recombinant soluble expression in E. coli. Immunobiology 2020; 225:151953. [PMID: 32747028 PMCID: PMC7422833 DOI: 10.1016/j.imbio.2020.151953] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Accepted: 04/28/2020] [Indexed: 01/19/2023]
Abstract
Surfactant treatment for neonatal respiratory distress syndrome has dramatically improved survival of preterm infants. However, this has resulted in a markedly increased incidence of sequelae such as neonatal chronic inflammatory lung disease. The current surfactant preparations in clinical use lack the natural lung defence proteins surfactant proteins (SP)-A and D. These are known to have anti-inflammatory and anti-infective properties essential for maintaining healthy non-inflamed lungs. Supplementation of currently available animal derived surfactant therapeutics with these anti-inflammatory proteins in the first few days of life could prevent the development of inflammatory lung disease in premature babies. However, current systems for production of recombinant versions of SP-A and SP-D require a complex solubilisation and refolding protocol limiting expression at scale for drug development. Using a novel solubility tag, we describe the expression and purification of recombinant fragments of human (rfh) SP-A and SP-D using Escherichia coli without the need for refolding. We obtained a mean (± SD) of 23.3 (± 5.4) mg and 86 mg (± 3.5) per litre yield of rfhSP-A and rfhSP-D, respectively. rfhSP-D was trimeric and 68% bound to a ManNAc-affinity column, giving a final yield of 57.5 mg/litre of highly pure protein, substantially higher than the 3.3 mg/litre obtained through the standard refolding protocol. Further optimisation of this novel lab based method could potentially make rfhSP-A and rfhSP-D production more commercially feasible to enable development of novel therapeutics for the treatment of lung infection and inflammation.
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MESH Headings
- Cloning, Molecular
- Escherichia coli/genetics
- Escherichia coli/metabolism
- Gene Expression
- Humans
- Models, Molecular
- Protein Conformation
- Protein Multimerization
- Receptors, Cell Surface/chemistry
- Receptors, Cell Surface/genetics
- Receptors, Cell Surface/isolation & purification
- Receptors, Cell Surface/metabolism
- Receptors, Immunologic/chemistry
- Receptors, Immunologic/genetics
- Receptors, Immunologic/isolation & purification
- Receptors, Immunologic/metabolism
- Recombinant Proteins
- Structure-Activity Relationship
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Affiliation(s)
- Alastair Watson
- Department of Child Health, Division of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, United Kingdom.
| | - Grith L Sørensen
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark
| | - Uffe Holmskov
- Department of Cancer and Inflammation, University of Southern Denmark, Odense, Denmark
| | - Harry J Whitwell
- Department of Chemical Engineering, Faculty of Engineering, Imperial College London, London, UK; Department of Metabolomics, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, UK
| | - Jens Madsen
- Department of Child Health, Division of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, United Kingdom
| | - Howard Clark
- Department of Child Health, Division of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, United Kingdom
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Paterson JM, Shaw AJ, Burns I, Dodds AW, Prasad A, Reid KB, Greenhough TJ, Shrive AK. Atomic-resolution crystal structures of the immune protein conglutinin from cow reveal specific interactions of its binding site with N-acetylglucosamine. J Biol Chem 2019; 294:17155-17165. [PMID: 31562242 PMCID: PMC6851296 DOI: 10.1074/jbc.ra119.010271] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 09/25/2019] [Indexed: 12/02/2022] Open
Abstract
Bovine conglutinin is an immune protein that is involved in host resistance to microbes and parasites and interacts with complement component iC3b, agglutinates erythrocytes, and neutralizes influenza A virus. Here, we determined the high-resolution (0.97–1.46 Å) crystal structures with and without bound ligand of a recombinant fragment of conglutinin's C-terminal carbohydrate-recognition domain (CRD). The structures disclosed that the high-affinity ligand N-acetyl-d-glucosamine (GlcNAc) binds in the collectin CRD calcium site by interacting with the O3′ and O4′ hydroxyls alongside additional specific interactions of the N-acetyl group oxygen and nitrogen with Lys-343 and Asp-320, respectively. These residues, unique to conglutinin and differing both in sequence and in location from those in other collectins, result in specific, high-affinity binding for GlcNAc. The binding pocket flanking residue Val-339, unlike the equivalent Arg-343 in the homologous human surfactant protein D, is sufficiently small to allow conglutinin Lys-343 access to the bound ligand, whereas Asp-320 lies in an extended loop proximal to the ligand-binding site and bounded at both ends by conserved residues that coordinate to both calcium and ligand. This loop becomes ordered on ligand binding. The electron density revealed both α and β anomers of GlcNAc, consistent with the added α/βGlcNAc mixture. Crystals soaked with α1–2 mannobiose, a putative component of iC3b, reported to bind to conglutinin, failed to reveal bound ligand, suggesting a requirement for presentation of mannobiose as part of an extended physiological ligand. These results reveal a highly specific GlcNAc-binding pocket in conglutinin and a novel collectin mode of carbohydrate recognition.
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Affiliation(s)
- Janet M Paterson
- School of Life Sciences, Keele University, Staffordshire ST5 5BG, United Kingdom
| | - Amy J Shaw
- School of Life Sciences, Keele University, Staffordshire ST5 5BG, United Kingdom
| | - Ian Burns
- School of Life Sciences, Keele University, Staffordshire ST5 5BG, United Kingdom
| | - Alister W Dodds
- MRC Immunochemistry Unit, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom
| | - Alpana Prasad
- MRC Immunochemistry Unit, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom
| | - Ken B Reid
- MRC Immunochemistry Unit, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom
| | - Trevor J Greenhough
- School of Life Sciences, Keele University, Staffordshire ST5 5BG, United Kingdom
| | - Annette K Shrive
- School of Life Sciences, Keele University, Staffordshire ST5 5BG, United Kingdom
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4
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Mackay RA, Townsend JP, Calvert J, Anthony M, Wilkinson AR, Postle AD, Clark HW, Todd DA. Increased surfactant protein-D levels in the airways of preterm neonates with sepsis indicated responses to infectious challenges. Acta Paediatr 2019; 108:870-876. [PMID: 30375054 PMCID: PMC6492096 DOI: 10.1111/apa.14630] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 10/11/2018] [Accepted: 10/25/2018] [Indexed: 11/30/2022]
Abstract
AIM Sepsis is multifactorial and potentially devastating for preterm neonates. Changes in surfactant protein-D (SP-D), phosphatidylcholine (PC) and PC molecular species during infection may indicate innate immunity or inflammation during sepsis. We aimed to compare these important pulmonary molecules in ventilated neonates without or with sepsis. METHODS Endotracheal aspirates were collected from preterm neonates born at 23-35 weeks and admitted to the neonatal intensive care unit at the John Radcliffe Hospital, Oxford, UK, from October 2000 to March 2002. Samples were collected at one day to 30 days and analysed for SP-D, total PC and PC molecular species concentrations using enzyme-linked immunosorbent assay and mass spectrometry. RESULTS We found that 8/54 (14.8%) neonates developed sepsis. SP-D (p < 0.0001), mono- and di-unsaturated PC were significantly increased (p = 0.05), and polyunsaturated PC was significantly decreased (p < 0.01) during sepsis compared to controls. SP-D:PC ratios were significantly increased during sepsis (p < 0.001), and SP-D concentrations were directly related to gestational age in neonates with sepsis (r2 = 0.389, p < 0.01). CONCLUSION Increased SP-D levels and changes in PC molecular species during sepsis were consistent with direct or indirect pulmonary inflammatory processes. Very preterm neonates we able to mount an acute inflammatory innate immune response to infectious challenges, despite low levels of surfactant proteins at birth.
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Affiliation(s)
- Rose‐Marie A. Mackay
- Faculty of Medicine Child Health, Academic Unit of Clinical and Experimental Sciences University of Southampton Southampton UK
| | - J. Paul Townsend
- Respiratory Biomedical Research Unit Southampton NIHR Southampton UK
- Neonatal Intensive Care Unit Princess Anne Hospital University Hospital Southampton NHS Foundation Trust Southampton UK
| | - Jennifer Calvert
- Neonatal Intensive Care Unit Cardiff and Vale University Health Board University Hospital of Wales Cardiff Wales UK
- Neonatal Intensive Care Unit Department of Paediatrics John Radcliffe Hospital University of Oxford Oxford UK
| | - Mark Anthony
- Neonatal Intensive Care Unit Department of Paediatrics John Radcliffe Hospital University of Oxford Oxford UK
| | - Andrew R. Wilkinson
- Neonatal Intensive Care Unit Department of Paediatrics John Radcliffe Hospital University of Oxford Oxford UK
| | - Anthony D. Postle
- Faculty of Medicine Child Health, Academic Unit of Clinical and Experimental Sciences University of Southampton Southampton UK
- Respiratory Biomedical Research Unit Southampton NIHR Southampton UK
- Neonatal Intensive Care Unit Princess Anne Hospital University Hospital Southampton NHS Foundation Trust Southampton UK
| | - Howard W. Clark
- Faculty of Medicine Child Health, Academic Unit of Clinical and Experimental Sciences University of Southampton Southampton UK
- Respiratory Biomedical Research Unit Southampton NIHR Southampton UK
- Neonatal Intensive Care Unit Princess Anne Hospital University Hospital Southampton NHS Foundation Trust Southampton UK
- Neonatal Intensive Care Unit Department of Paediatrics John Radcliffe Hospital University of Oxford Oxford UK
| | - David A. Todd
- Faculty of Medicine Child Health, Academic Unit of Clinical and Experimental Sciences University of Southampton Southampton UK
- Department of Neonatology Centenary Hospital Canberra ACT Australia
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5
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Fraser RS, Arroyo LG, Meyer A, Lillie BN. Identification of genetic variation in equine collagenous lectins using targeted resequencing. Vet Immunol Immunopathol 2018; 202:153-163. [PMID: 30078590 DOI: 10.1016/j.vetimm.2018.07.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 06/28/2018] [Accepted: 07/02/2018] [Indexed: 12/30/2022]
Abstract
Collagenous lectins are a family of soluble pattern recognition receptors that play an important role in innate immune resistance to infectious disease. Through recognition of carbohydrate motifs on the surface of pathogens, some collagenous lectins can activate the lectin pathway of complement, providing an effective means of host defense. Genetic polymorphisms in collagenous lectins have been shown in several species to predispose animals to a variety of infectious diseases. Infectious diseases are an important cause of morbidity in horses, however little is known regarding the role of equine collagenous lectins. Using a high-throughput, targeted re-sequencing approach, the relationship between genetic variation in equine collagenous lectin genes and susceptibility to disease was investigated. DNA was isolated from tissues obtained from horses submitted for post-mortem examination. Animals were divided into two populations, those with infectious or autoinflammatory diseases (n = 37) and those without (n = 52), and then subdivided by dominant pathological process for a total of 21 pools, each containing 4-5 horses. DNA was extracted from each horse and pooled in equimolar amounts, and the exons, introns, upstream (approximately 50 kb) and downstream (approximately 3 kb) regulatory regions for the 11 equine collagenous lectin genes and related MASP genes were targeted for re-sequencing. A custom target capture kit was used to prepare a sequencing library, which was sequenced on an Illumina MiSeq. After implementing quality control filters, 4559 variants were identified. Of these, 92 were present in the coding regions (43 missense, 1 nonsense, and 48 synonymous), 1414 in introns, 3029 in the upstream region, and 240 in the downstream region. In silico analysis of the missense short nucleotide variants identified 12 mutations with potential to disrupt collagenous lectin protein structure or function, 280 mutations located within predicted transcription factor binding sites, and 95 mutations located within predicted microRNA binding elements. Analysis of allelic association identified 113 mutations that segregated between the infectious/autoinflammatory and non-infectious populations. The variants discovered in this experiment represent potential genetic contributors to disease susceptibility of horses, and will serve as candidates for further population-level genotyping. This study contributes to the growing body of evidence that pooled, high-throughput sequencing is a viable strategy for cost-effective variant discovery.
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Affiliation(s)
- Russell S Fraser
- Department of Pathobiology, University of Guelph, Guelph, Ontario, N1E 2W1, Canada.
| | - Luis G Arroyo
- Department of Clinical Studies, University of Guelph, Guelph, Ontario, N1E 2W1, Canada.
| | - Ann Meyer
- Department of Pathobiology, University of Guelph, Guelph, Ontario, N1E 2W1, Canada.
| | - Brandon N Lillie
- Department of Pathobiology, University of Guelph, Guelph, Ontario, N1E 2W1, Canada.
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6
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Arroyo R, Martín-González A, Echaide M, Jain A, Brondyk W, Rosenbaum J, Moreno-Herrero F, Pérez-Gil J. Supramolecular Assembly of Human Pulmonary Surfactant Protein SP-D. J Mol Biol 2018; 430:1495-1509. [DOI: 10.1016/j.jmb.2018.03.027] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 03/26/2018] [Accepted: 03/26/2018] [Indexed: 11/15/2022]
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7
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Ujma S, Horsnell WGC, Katz AA, Clark HW, Schäfer G. Non-Pulmonary Immune Functions of Surfactant Proteins A and D. J Innate Immun 2016; 9:3-11. [PMID: 27794581 DOI: 10.1159/000451026] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 09/26/2016] [Indexed: 11/19/2022] Open
Abstract
Surfactant proteins A (SP-A) and D (SP-D) are established as essential components of our innate immune system for protecting the lung from pathogens and allergens. They essentially exert their protective functions by regulating pulmonary homeostasis. Both proteins are however widely expressed throughout the body, including the female reproductive tract, urinary tract, gastrointestinal tract, the eye, ear, nasal compartment, central nervous system, the coronary artery and the skin. The functions of SP-A and SP-D at these sites are a relatively underinvestigated area, but it is emerging that both SP-A and SP-D contribute significantly to the regulation of inflammation and protection from infection at these sites. This review presents our current understanding of the roles of SP-A and SP-D in non-pulmonary sites.
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Affiliation(s)
- Sylvia Ujma
- UCT Receptor Biology Research Unit, Division of Medical Biochemistry and Structural Biology, Department of Integrative Biomedical Sciences, University of Cape Town, Cape Town, South Africa
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8
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Nogueira E, Mangialavori IC, Loureiro A, Azoia NG, Sárria MP, Nogueira P, Freitas J, Härmark J, Shimanovich U, Rollett A, Lacroix G, Bernardes GJL, Guebitz G, Hebert H, Moreira A, Carmo AM, Rossi JPFC, Gomes AC, Preto A, Cavaco-Paulo A. Peptide Anchor for Folate-Targeted Liposomal Delivery. Biomacromolecules 2015; 16:2904-10. [PMID: 26241560 DOI: 10.1021/acs.biomac.5b00823] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Specific folate receptors are abundantly overexpressed in chronically activated macrophages and in most cancer cells. Directed folate receptor targeting using liposomes is usually achieved using folate linked to a phospholipid or cholesterol anchor. This link is formed using a large spacer like polyethylene glycol. Here, we report an innovative strategy for targeted liposome delivery that uses a hydrophobic fragment of surfactant protein D linked to folate. Our proposed spacer is a small 4 amino acid residue linker. The peptide conjugate inserts deeply into the lipid bilayer without affecting liposomal integrity, with high stability and specificity. To compare the drug delivery potential of both liposomal targeting systems, we encapsulated the nuclear dye Hoechst 34580. The eventual increase in blue fluorescence would only be detectable upon liposome disruption, leading to specific binding of this dye to DNA. Our delivery system was proven to be more efficient (2-fold) in Caco-2 cells than classic systems where the folate moiety is linked to liposomes by polyethylene glycol.
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Affiliation(s)
- Eugénia Nogueira
- CBMA - Centre of Molecular and Environmental Biology, Department of Biology, University of Minho , Braga 4710-057, Portugal.,CEB - Centre of Biological Engineering, University of Minho , Braga 4710-057, Portugal
| | - Irene C Mangialavori
- IQUIFIB - Instituto de Química y Fisicoquímica Biológicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, CONICET , 1113 Buenos Aires, Argentina
| | - Ana Loureiro
- CBMA - Centre of Molecular and Environmental Biology, Department of Biology, University of Minho , Braga 4710-057, Portugal.,CEB - Centre of Biological Engineering, University of Minho , Braga 4710-057, Portugal
| | - Nuno G Azoia
- CEB - Centre of Biological Engineering, University of Minho , Braga 4710-057, Portugal
| | - Marisa P Sárria
- CEB - Centre of Biological Engineering, University of Minho , Braga 4710-057, Portugal
| | - Patrícia Nogueira
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto , Porto, Portugal.,IBMC - Instituto de Biologia Molecular e Celular , 4150-180 Porto, Portugal
| | - Jaime Freitas
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto , Porto, Portugal.,IBMC - Instituto de Biologia Molecular e Celular , 4150-180 Porto, Portugal
| | - Johan Härmark
- Department of Biosciences and Nutrition, The Royal Institute of Technology, School of Technology and Health, Karolinska Institutet , S-14183 Huddinge, Sweden
| | - Ulyana Shimanovich
- Department of Chemistry, University of Cambridge , Cambridge CB2 1EW, United Kingdom
| | - Alexandra Rollett
- Institute of Environmental Biotechnology, University of Natural Resources and Life Sciences , 3430 Tulln, Austria
| | - Ghislaine Lacroix
- INERIS - Institut National de l'Environnement Industriel et des Risques , 60550 Verneuil en Halatte, France
| | - Gonçalo J L Bernardes
- Department of Chemistry, University of Cambridge , Cambridge CB2 1EW, United Kingdom
| | - Georg Guebitz
- Institute of Environmental Biotechnology, University of Natural Resources and Life Sciences , 3430 Tulln, Austria
| | - Hans Hebert
- Department of Biosciences and Nutrition, The Royal Institute of Technology, School of Technology and Health, Karolinska Institutet , S-14183 Huddinge, Sweden
| | - Alexandra Moreira
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto , Porto, Portugal.,IBMC - Instituto de Biologia Molecular e Celular , 4150-180 Porto, Portugal
| | - Alexandre M Carmo
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto , Porto, Portugal.,IBMC - Instituto de Biologia Molecular e Celular , 4150-180 Porto, Portugal.,ICBAS - Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto , 4099-003 Porto, Portugal
| | - Juan Pablo F C Rossi
- IQUIFIB - Instituto de Química y Fisicoquímica Biológicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, CONICET , 1113 Buenos Aires, Argentina
| | - Andreia C Gomes
- CBMA - Centre of Molecular and Environmental Biology, Department of Biology, University of Minho , Braga 4710-057, Portugal
| | - Ana Preto
- CBMA - Centre of Molecular and Environmental Biology, Department of Biology, University of Minho , Braga 4710-057, Portugal
| | - Artur Cavaco-Paulo
- CEB - Centre of Biological Engineering, University of Minho , Braga 4710-057, Portugal
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Miyake Y, Oh-hora M, Yamasaki S. C-Type Lectin Receptor MCL Facilitates Mincle Expression and Signaling through Complex Formation. THE JOURNAL OF IMMUNOLOGY 2015; 194:5366-74. [DOI: 10.4049/jimmunol.1402429] [Citation(s) in RCA: 91] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Accepted: 03/16/2015] [Indexed: 01/23/2023]
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10
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Henriksen ML, Brandt J, Iyer SSC, Thielens NM, Hansen S. Characterization of the interaction between collectin 11 (CL-11, CL-K1) and nucleic acids. Mol Immunol 2013; 56:757-67. [PMID: 23954398 DOI: 10.1016/j.molimm.2013.07.011] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Revised: 07/15/2013] [Accepted: 07/17/2013] [Indexed: 01/22/2023]
Abstract
Collectins are a group of innate immune proteins that contain collagen-like regions and globular C-type lectin domains. Via the lectin domains, collectins recognize and bind to various microbial carbohydrate patterns. Collectin 11 (CL-11) exists in complex with the complement activating MBL-associated proteases, MASPs. In the present work, we characterize the interaction between CL-11 and DNA, and show that CL-11 binds to DNA from a variety of origins in a calcium-independent manner. CL-11 binds also to apoptotic cells presenting extracellular DNA on their surface. The binding to DNA is sensitive to changes in ionic strength and pH. Competition studies show that CL-11 binds to nucleic acids and carbohydrates via separate binding-sites and oligomericity appears crucial for binding activity. Combined interaction with DNA and mannan strongly increases binding avidity. By surface plasmon resonance we estimate the dissociation constant for the binding between CL-11 and double stranded DNA oligonucleotides to K(D)=9-20 nM. In an in vitro assay we find that CL-11 binds to DNA coated surfaces, which leads to C4b deposition via MASP-2. We propose that CL-11, e.g. via complement, may play a role in response to particles and surfaces presenting extracellular DNA, such as apopototic cells, neutrophil extracellular traps and biofilms.
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Affiliation(s)
- Maiken L Henriksen
- Department of Cancer & Inflammation Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
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11
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Azoia NG, Fernandes MM, Micaêlo NM, Soares CM, Cavaco-Paulo A. Molecular modeling of hair keratin/peptide complex: Using MM-PBSA calculations to describe experimental binding results. Proteins 2012; 80:1409-17. [DOI: 10.1002/prot.24037] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2011] [Revised: 12/23/2011] [Accepted: 12/29/2011] [Indexed: 11/11/2022]
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12
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Song Y, Fang G, Shen H, Li H, Yang W, Pan B, Huang G, Lin G, Ma L, Willard B, Gu J, Zheng L, Wang Y. Human surfactant protein A2 gene mutations impair dimmer/trimer assembly leading to deficiency in protein sialylation and secretion. PLoS One 2012; 7:e46559. [PMID: 23056344 PMCID: PMC3463533 DOI: 10.1371/journal.pone.0046559] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Accepted: 08/31/2012] [Indexed: 02/05/2023] Open
Abstract
Surfactant protein A2 (SP-A2) plays an essential role in surfactant metabolism and lung host defense. SP-A2 mutations in the carbohydrate recognition domain have been related to familial pulmonary fibrosis and can lead to a recombinant protein secretion deficiency in vitro. In this study, we explored the molecular mechanism of protein secretion deficiency and the subsequent biological effects in CHO-K1 cells expressing both wild-type and several different mutant forms of SP-A2. We demonstrate that the SP-A2 G231V and F198S mutants impair the formation of dimmer/trimer SP-A2 which contributes to the protein secretion defect. A deficiency in sialylation, but not N-linked glycosylation, is critical to the observed dimmer/trimer impairment-induced secretion defect. Furthermore, both mutant forms accumulate in the ER and form NP-40-insoluble aggregates. In addition, the soluble mutant SP-A2 could be partially degraded through the proteasome pathway but not the lysosome or autophagy pathway. Intriguingly, 4-phenylbutyrate acid (4-PBA), a chemical chaperone, alleviates aggregate formation and partially rescued the protein secretion of SP-A2 mutants. In conclusion, SP-A2 G231V and F198S mutants impair the dimmer/trimer assembly, which contributes to the protein sialylation and secretion deficiency. The intracellular protein mutants could be partially degraded through the proteasome pathway and also formed aggregates. The treatment of the cells with 4-PBA resulted in reduced aggregation and rescued the secretion of mutant SP-A2.
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Affiliation(s)
- Yi Song
- Department of Pathology, Shantou University Medical College, Shantou, Guangdong, People’s Republic of China
| | - Guodong Fang
- Department of Pathology, Shantou University Medical College, Shantou, Guangdong, People’s Republic of China
| | - Haitao Shen
- Department of Pathology, Shantou University Medical College, Shantou, Guangdong, People’s Republic of China
| | - Hui Li
- Department of Pathology, Shantou University Medical College, Shantou, Guangdong, People’s Republic of China
| | - Wenbing Yang
- Department of Pathology, Shantou University Medical College, Shantou, Guangdong, People’s Republic of China
| | - Bing Pan
- The Institute of Cardiovascular Sciences and Institute of Systems Biomedicine, School of Basic Medical Sciences, Peking University Health Science Center, Key Laboratory of Molecular Cardiovascular Sciences of Education Ministry, and Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides of Health Ministry, Beijing, People’s Republic of China
| | - Guowei Huang
- Department of Pathology, Shantou University Medical College, Shantou, Guangdong, People’s Republic of China
| | - Guangyu Lin
- Department of Pediatrics, Second Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong, People’s Republic of China
- Translational Medicine Center, Second Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong, People’s Republic of China
| | - Lian Ma
- Department of Pediatrics, Second Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong, People’s Republic of China
- Translational Medicine Center, Second Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong, People’s Republic of China
| | - Belinda Willard
- Proteomics Laboratory, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Jiang Gu
- Department of Pathology, Shantou University Medical College, Shantou, Guangdong, People’s Republic of China
| | - Lemin Zheng
- The Institute of Cardiovascular Sciences and Institute of Systems Biomedicine, School of Basic Medical Sciences, Peking University Health Science Center, Key Laboratory of Molecular Cardiovascular Sciences of Education Ministry, and Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides of Health Ministry, Beijing, People’s Republic of China
- * E-mail: (YW); (LZ)
| | - Yongyu Wang
- Department of Pathology, Shantou University Medical College, Shantou, Guangdong, People’s Republic of China
- * E-mail: (YW); (LZ)
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13
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Abstract
PURPOSE OF REVIEW Immune reconstitution inflammatory syndrome (IRIS) is a common occurrence in HIV patients starting antiretroviral therapy (ART), and pulmonary involvement is an important feature of tuberculosis-IRIS and pneumocystis-IRIS. Pulmonologists need an awareness of the timing, presentation and treatment of pulmonary IRIS. RECENT FINDINGS Case definitions for tuberculosis-IRIS and cryptococcal-IRIS have been published by the International Network for the Study of HIV-associated IRIS (INSHI). A number of studies have addressed validation of clinical case definitions and the optimal time to commence ART after diagnosis of an opportunistic infection in HIV patients. The pathogenesis of IRIS is being assessed at a molecular level, increasing our understanding of mechanisms and possible targets for future preventive and therapeutic strategies. SUMMARY Tuberculosis-IRIS, nontuberculosis mycobacterial-IRIS and pneumocystis-IRIS occur within days to weeks of starting ART, causing substantial morbidity, but low mortality. Cryptococcal-IRIS usually occurs later in the course of ART, and may be associated with appreciable mortality. Early recognition of unmasking and paradoxical IRIS affecting the lung allows timely initiation of antimicrobial and/or immunomodulatory therapies.
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14
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Xu C, Yu Z, Inouye M, Brodsky B, Mirochnitchenko O. Expanding the family of collagen proteins: recombinant bacterial collagens of varying composition form triple-helices of similar stability. Biomacromolecules 2010; 11:348-56. [PMID: 20025291 DOI: 10.1021/bm900894b] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The presence of the (Gly-Xaa-Yaa)(n) open reading frames in different bacteria predicts the existence of an expanded family of collagen-like proteins. To further explore the triple-helix motif and stabilization mechanisms in the absence of hydroxyproline (Hyp), predicted novel collagen-like proteins from Gram-positive and -negative bacteria were expressed in Escherichia coli and characterized. Soluble proteins capable of successful folding and in vitro refolding were observed for collagen proteins from Methylobacterium sp 4-46, Rhodopseudomonas palustris and Solibacter usitatus . In contrast, all protein constructs from Clostridium perfringens were found predominantly in inclusion bodies. However, attachment of a heterologous N-terminal or C-terminal noncollagenous folding domain induced the Clostridium perfringens collagen domain to fold and become soluble. The soluble constructs from different bacteria had typical collagen triple-helical features and showed surprisingly similar thermal stabilities despite diverse amino acid compositions. These collagen-like proteins provide a resource for the development of biomaterials with new properties.
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Affiliation(s)
- Chunying Xu
- Department of Biochemistry, University of Medicine and Dentistry of New Jersey, Piscataway, 08854, USA
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15
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Forbes LR, Haczku A. SP-D and regulation of the pulmonary innate immune system in allergic airway changes. Clin Exp Allergy 2010; 40:547-62. [PMID: 20447075 DOI: 10.1111/j.1365-2222.2010.03483.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The airway mucosal surfaces are constantly exposed to inhaled particles that can be potentially toxic, infectious or allergenic and should elicit inflammatory changes. The proximal and distal air spaces, however, are normally infection and inflammation free due to a specialized interplay between cellular and molecular components of the pulmonary innate immune system. Surfactant protein D (SP-D) is an epithelial-cell-derived immune modulator that belongs to the small family of structurally related Ca(2+)-dependent C-type collagen-like lectins. While collectins can be detected in mucosal surfaces of various organs, SP-A and SP-D (the 'lung collectins') are constitutively expressed in the lung at high concentrations. Both proteins are considered important players of the pulmonary immune responses. Under normal conditions however, SP-A-/- mice display no pathological features in the lung. SP-D-/- mice, on the other hand, show chronic inflammatory alterations indicating a special importance of this molecule in regulating immune homeostasis and the function of the innate immune cells. Recent studies in our laboratory and others implied significant associations between changes in SP-D levels and the presence of airway inflammation both in animal models and patients raising a potential usefulness of this molecule as a disease biomarker. Research on wild-type and mutant recombinant molecules in vivo and in vitro showed that SP-D binds carbohydrates, lipids and nucleic acids with a broad spectrum specificity and initiates phagocytosis of inhaled pathogens as well as apoptotic cells. Investigations on gene-deficient and conditional over expressor mice in addition, provided evidence that SP-D directly modulates macrophage and dendritic cell function as well as T cell-dependent inflammatory events. Thus, SP-D has a unique, dual functional capacity to induce pathogen elimination on the one hand and control of pro-inflammatory mechanisms on the other, suggesting a potential suitability for therapeutic prevention and treatment of chronic airway inflammation without compromising the host defence function of the airways. This paper will review recent findings on the mechanisms of immune-protective function of SP-D in the lung.
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Affiliation(s)
- L R Forbes
- Department of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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16
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Seaton BA, Crouch EC, McCormack FX, Head JF, Hartshorn KL, Mendelsohn R. Review: Structural determinants of pattern recognition by lung collectins. Innate Immun 2010; 16:143-50. [PMID: 20423923 DOI: 10.1177/1753425910368716] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Host defense roles for the lung collectins, surfactant protein A (SP-A) and surfactant protein D (SP-D), were first suspected in the 1980s when molecular characterization revealed their sequence homology to the acute phase reactant of serum, mannose-binding lectin. Surfactant protein A and SP-D have since been shown to play diverse and important roles in innate immunity and pulmonary homeostasis. Their location in surfactant ideally positions them to interact with air-space pathogens. Despite extensive structural similarity, the two proteins show many functional differences and considerable divergence in their interactions with microbial surface components, surfactant lipids, and other ligands. Recent crystallographic studies have provided many new insights relating to these observed differences. Although both proteins can participate in calcium-dependent interactions with sugars and other polyols, they display significant differences in the spatial orientation, charge, and hydrophobicity of their binding surfaces. Surfactant protein D appears particularly adapted to interactions with complex carbohydrates and anionic phospholipids, such as phosphatidylinositol. By contrast, SP-A shows features consistent with its preference for lipid ligands, including lipid A and the major surfactant lipid, dipalmitoylphosphatidylcholine. Current research suggests that structural biology approaches will help to elucidate the molecular basis of pulmonary collectin-ligand recognition and facilitate development of new therapeutics based upon SP-A and SP-D.
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Affiliation(s)
- Barbara A Seaton
- Department of Physiology and Biophysics, Boston University School of Medicine, Massachusetts, USA.
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17
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Thomsen T, Moeller JB, Schlosser A, Sorensen GL, Moestrup SK, Palaniyar N, Wallis R, Mollenhauer J, Holmskov U. The recognition unit of FIBCD1 organizes into a noncovalently linked tetrameric structure and uses a hydrophobic funnel (S1) for acetyl group recognition. J Biol Chem 2009; 285:1229-38. [PMID: 19892701 DOI: 10.1074/jbc.m109.061523] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We have recently identified FIBCD1 (Fibrinogen C domain containing 1) as a type II transmembrane endocytic receptor located primarily in the intestinal brush border. The ectodomain of FIBCD1 comprises a coiled coil, a polycationic region, and a C-terminal FReD (fibrinogen-related domain) that assembles into disulfide-linked homotetramers. The FIBCD1-FReD binds Ca(2+) dependently to acetylated structures like chitin, N-acetylated carbohydrates, and amino acids. FReDs are present in diverse innate immune pattern recognition proteins including the ficolins and horseshoe crab TL5A. Here, we use chemical cross-linking, combined with analytical ultracentrifugation and electron microscopy of the negatively stained recombinant FIBCD1-FReD to show that it assembles into noncovalent tetramers in the absence of the coiled coil. We use surface plasmon resonance, carbohydrate binding, and pulldown assays combined with site-directed mutagenesis to define the binding site involved in the interaction of FIBCD1 with acetylated structures. We show that mutations of central residues (A432V and H415G) in the hydrophobic funnel (S1) abolish the binding of FIBCD1 to acetylated bovine serum albumin and chitin. The double mutations (D393N/D395A) at the putative calcium-binding site reduce the ability of FIBCD1 to bind ligands. We conclude that the FReDs of FIBCD1 forms noncovalent tetramers and that the acetyl-binding site of FReDs of FIBCD1 is homologous to that of tachylectin 5A and M-ficolin but not to the FReD of L-ficolin. We suggest that the spatial organization of the FIBCD1-FReDs determine the molecular pattern recognition specificity and subsequent biological functions.
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Affiliation(s)
- Theresa Thomsen
- Medical Biotechnology Center, University of Southern Denmark, 5000 Odense, Denmark
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18
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Atochina-Vasserman EN, Gow AJ, Abramova H, Guo CJ, Tomer Y, Preston AM, Beck JM, Beers MF. Immune reconstitution during Pneumocystis lung infection: disruption of surfactant component expression and function by S-nitrosylation. THE JOURNAL OF IMMUNOLOGY 2009; 182:2277-87. [PMID: 19201882 DOI: 10.4049/jimmunol.0802775] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Pneumocystis pneumonia (PCP), the most common opportunistic pulmonary infection associated with HIV infection, is marked by impaired gas exchange and significant hypoxemia. Immune reconstitution disease (IRD) represents a syndrome of paradoxical respiratory failure in patients with active or recently treated PCP subjected to immune reconstitution. To model IRD, C57BL/6 mice were selectively depleted of CD4(+) T cells using mAb GK1.5. Following inoculation with Pneumocystis murina cysts, infection was allowed to progress for 2 wk, GK1.5 was withdrawn, and mice were followed for another 2 or 4 wk. Flow cytometry of spleen cells demonstrated recovery of CD4(+) cells to >65% of nondepleted controls. Lung tissue and bronchoalveolar lavage fluid harvested from IRD mice were analyzed in tandem with samples from CD4-depleted mice that manifested progressive PCP for 6 wks. Despite significantly decreased pathogen burdens, IRD mice had persistent parenchymal lung inflammation, increased bronchoalveolar lavage fluid cellularity, markedly impaired surfactant biophysical function, and decreased amounts of surfactant phospholipid and surfactant protein (SP)-B. Paradoxically, IRD mice also had substantial increases in the lung collectin SP-D, including significant amounts of an S-nitrosylated form. By native PAGE, formation of S-nitrosylated SP-D in vivo resulted in disruption of SP-D multimers. Bronchoalveolar lavage fluid from IRD mice selectively enhanced macrophage chemotaxis in vitro, an effect that was blocked by ascorbate treatment. We conclude that while PCP impairs pulmonary function and produces abnormalities in surfactant components and biophysics, these responses are exacerbated by IRD. This worsening of pulmonary inflammation, in response to persistent Pneumocystis Ags, is mediated by recruitment of effector cells modulated by S-nitrosylated SP-D.
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Affiliation(s)
- Elena N Atochina-Vasserman
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
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19
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Haczku A. Protective role of the lung collectins surfactant protein A and surfactant protein D in airway inflammation. J Allergy Clin Immunol 2008; 122:861-79; quiz 880-1. [PMID: 19000577 DOI: 10.1016/j.jaci.2008.10.014] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2008] [Revised: 10/13/2008] [Accepted: 10/13/2008] [Indexed: 12/30/2022]
Abstract
The acute inflammatory airway response is characterized by a time-dependent onset followed by active resolution. Emerging evidence suggests that epithelial cells of the proximal and distal air spaces release host defense mediators that can facilitate both the initiation and the resolution part of inflammatory airway changes. These molecules, also known as the hydrophilic surfactant proteins (surfactant protein [SP]-A and SP-D) belong to the class of collagenous lectins (collectins). The collectins are a small family of soluble pattern recognition receptors containing collagenous regions and C-type lectin domains. SP-A and SP-D are most abundant in the lung. Because of their structural uniqueness, specific localization, and functional versatility, lung collectins are important players of the pulmonary immune responses. Recent studies in our laboratory and others indicated significant associations of lung collectin levels with acute and chronic airway inflammation in both animal models and patients, suggesting the usefulness of these molecules as disease biomarkers. Research on wild-type and mutant recombinant molecules in vivo and in vitro showed that SP-A and SP-D bind carbohydrates, lipids, and nucleic acids with a broad-spectrum specificity and initiate phagocytosis of inhaled pathogens as well as apoptotic cells. Investigations on gene-deficient and conditional overexpresser mice indicated that lung collectins also directly modulate innate immune cell function and T-cell-dependent inflammatory events. Thus, these molecules have a unique, dual-function capacity to induce pathogen elimination and control proinflammatory mechanisms, suggesting a potential suitability for therapeutic prevention and treatment of chronic airway inflammation. This article reviews evidence supporting that the lung collectins play an immune-protective role and are essential for maintenance of the immunologic homeostasis in the lung.
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Affiliation(s)
- Angela Haczku
- Department of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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20
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Araújo R, Cavaco‐Paulo A, Casal M. Strategies towards the Functionalization of Subtilisin E from Bacillus subtilis for Wool Finishing Applications. Eng Life Sci 2008. [DOI: 10.1002/elsc.200700056] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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21
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Wang G, Myers C, Mikerov A, Floros J. Effect of cysteine 85 on biochemical properties and biological function of human surfactant protein A variants. Biochemistry 2007; 46:8425-35. [PMID: 17580966 PMCID: PMC2531219 DOI: 10.1021/bi7004569] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Four "core" amino acid differences within the collagen-like domain distinguish the human surfactant protein A1 (SP-A1) variants from the SP-A2 variants. One of these, cysteine 85 that could form intermolecular disulfide bonds, is present in SP-A1 (Cys85) and absent in SP-A2 (Arg85). We hypothesized that residue 85 affects both the structure and function of SP-A1 and SP-A2 variants. To test this, wild-type (WT) variants, 6A2 of SP-A1 and 1A0 of SP-A2, and their mutants (6A2(C85R) and 1A0(R85C)) were generated and studied. We found the following: (1) Residue 85 affected the binding ability to mannose and the oligomerization pattern of SP-As. The 1A0(R85C) and 6A2(C85R) patterns were similar and/or resembled those of WT 6A2 and 1A0, respectively. (2) Both SP-A WT and mutants differentially induced rough LPS and Pseudomonas aeruginosa aggregation in the following order: 1A0 > 6A2 > 6A2(C85R) > 1A0(R85C) for Re-LPS aggregation and 1A0 > 6A2 = 6A2(C85R) = 1A0(R85C) for bacterial aggregation. (3) SP-A WT and mutants enhanced phagocytosis of P. aeruginosa by rat alveolar macrophages. Their phagocytic index order was 6A2(C85R) > 1A0 > 6A2 = 1A0(R85C). The activity of mutant 1A0(C85R) was significantly lower than WT 1A0 but similar to 6A2. Compared to WT 6A2, the 6A2(C85R) mutant exhibited a significantly higher activity. These results indicate that the SP-A variant/mutant with Arg85 exhibits a higher ability to enhance bacterial phagocytosis than that with Cys85. Residue 85 plays an important role in the structure and function of SP-A and is a major factor for the differences between SP-A1 and SP-A2 variants.
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Affiliation(s)
- Guirong Wang
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
| | - Catherine Myers
- Department of Pediatrics, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
| | - Anatoly Mikerov
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
| | - Joanna Floros
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
- Department of Pediatrics, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
- Department of Obstetrics and Gynecology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
- * Corresponding author: Joanna Floros, Ph. D. Department of Cellular and Molecular Physiology, H166, The Pennsylvania State University College of Medicine, 500 University Drive, Hershey, PA 17033, USA, Telephone: (717) 531-6972, FAX: (717) 531-7667, E-mail:
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22
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Xu X, Li W, Fan X, Liang Y, Zhao M, Zhang J, Liang Y, Tong W, Wang J, Yang W, Lu Y. Identification and characterization of a novel p42.3 gene as tumor-specific and mitosis phase-dependent expression in gastric cancer. Oncogene 2007; 26:7371-9. [PMID: 17525738 DOI: 10.1038/sj.onc.1210538] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Multiple genetic alterations are attributed to gastric cancer (GC); however, only a few critical genes have been identified so far. In this study, we isolated and characterized a novel gene p42.3, represented as tumor-specific and mitosis phase-dependent expression protein in GC cell line BGC823. Our data showed that the expression of p42.3 was cell cycle-dependent in GC cell lines. Moreover, p42.3 was specifically expressed in primary GC tissues but not in the matched normal mucosa of stomach, and this gene was expressed in diverse embryonic tissues. Furthermore, significant suppression of cell proliferation and tumorigenicity were detected and G(2)/M phase arrest was observed in cell line BGC823 depleted of p42.3 expression by RNAi technique, and we confirmed the expression changes of cyclin B1 and Chk2 following the silence of p42.3. Taken together, we cloned and characterized p42.3 gene that was specifically expressed in GC tumors but not in normal gastric mucosa, and the gene was associated with M-phase regulation. Moreover, p42.3 might be involved in cell proliferation and tumorigenesis; therefore, this gene might have potential applications in the diagnosis or treatment of GC.
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Affiliation(s)
- X Xu
- Laboratory of Molecular Oncology, Beijing Institute for Cancer Research, School of Oncology, Peking University, Hai-Dian District, Beijing, China
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23
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Abstract
Collectins, present in plasma and on mucosal surfaces, are humoral molecules of the innate immune system. They were discovered a hundred years ago in 1906 as the first association of an animal lectin with the immune system. They are a family of calcium-dependent lectins that recognize pathogen-associated molecular patterns. They share a similar modular domain architecture consisting of four regions; a cysteine-rich N-terminal domain, a collagen-like region, an alpha-helical neck domain and a C-terminal carbohydrate recognition domain. There have been eight collectins members defined so far, of which, MBL, SP-A and SP-D are the most characterized. Collectins represent the first line of host defense. Upon recognition of the infectious agents, collectins put into action effector mechanisms like direct opsonization, neutralization, agglutination, complement activation and phagocytosis to curb the microbial growth. In addition, they also modulate inflammatory and allergic responses and apoptotic cell clearance. These functions limit infection and subsequently modulate the adaptive immune responses. The role of collectins, their structure, function, characteristics and clinical significance are reviewed in this article.
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Affiliation(s)
- Garima Gupta
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India
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24
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Zhou F, You G. Molecular insights into the structure-function relationship of organic anion transporters OATs. Pharm Res 2006; 24:28-36. [PMID: 17103332 DOI: 10.1007/s11095-006-9144-9] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2006] [Accepted: 08/02/2006] [Indexed: 12/27/2022]
Abstract
The organic anion transporter (OAT) family encoded by SLC22A mediates the absorption, distribution, and excretion of a diverse array of environmental toxins, and clinically important drugs, including anti-HIV therapeutics, anti-tumor drugs, antibiotics, anti-hypertensives, and anti-inflammatories, and therefore is critical for the survival of mammalian species. Several OATs have been identified: OAT1 (SLC22A6), OAT2 (SLC22A7), OAT3 (SLC22A8), OAT4 (SLC22A11), OAT5 (SLC22A19) OAT6 (SLC22A20) and URAT1 (SLC22A12). The expressions of these OATs have been detected in key organs such as kidney, liver, brain and placenta. OAT dysfunction in these organs may contribute to the renal, hepatic, neurological and fetal toxicity and diseases. In this review, we summarize, according to the work done by our laboratory as well as by others, the most updated molecular studies on these OAT members, especially on the aspect of their structure-function relationships. The functional roles of N-glycosylation, transmembrane domains and individual amino acids, cell surface assembly, as well as associating proteins will be discussed. In addition, we will show the recent analyses of coding region polymorphisms of OATs, which give us information on the genetic variants of OATs and their potential effects on OAT functions.
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Affiliation(s)
- Fanfan Zhou
- Department of Pharmaceutics, Rutgers, the State University of New Jersey, 160 Frelinghuysen Road, Piscataway, NJ 08854, USA
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25
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Kingma PS, Zhang L, Ikegami M, Hartshorn K, McCormack FX, Whitsett JA. Correction of Pulmonary Abnormalities in Sftpd-/- Mice Requires the Collagenous Domain of Surfactant Protein D. J Biol Chem 2006; 281:24496-505. [PMID: 16787926 DOI: 10.1074/jbc.m600651200] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Surfactant protein D (SP-D) is a member of the collectin family of innate defense proteins. Members of this family share four distinct structural domains: an N-terminal cross-linking domain, a collagenous domain, a neck region, and a carbohydrate recognition domain. In this study, the function of the collagenous domain was evaluated by expressing a SP-D collagen deletion mutant protein (rSftpdCDM) in wild type and SP-D null mice (Sftpd(-/-)). rSftpdCDM formed disulfide-linked trimers that further oligomerized into higher order structures. The mutant protein effectively bound carbohydrate and aggregated bacteria in vitro. Whereas rSftpdCDM did not disrupt pulmonary morphology or surfactant phospholipid levels in wild type mice, the mutant protein failed to rescue the emphysema or enlarged foamy macrophages that are characteristic of Sftpd(-/-) mice. Moreover, rSftpdCDM partitioned with small aggregate surfactant in a manner similar to SP-D, but rSftpdCDM did not correct the abnormal surfactant ultrastructure or phospholipid levels observed in Sftpd(-/-) mice. In contrast, rSftpdCDM completely corrected viral clearance and the abnormal inflammatory response that occurs following pulmonary influenza A challenge in Sftpd(-/-) mice. Our findings indicate that the collagen domain of SP-D is not required for assembly of disulfide-stabilized oligomers or the innate immune response to viral pathogens. The collagen domain of SP-D is required for the regulation of pulmonary macrophage activation, airspace remodeling, and surfactant lipid homeostasis.
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Affiliation(s)
- Paul S Kingma
- Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229-3039, USA
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26
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Lillie BN, Brooks AS, Keirstead ND, Hayes MA. Comparative genetics and innate immune functions of collagenous lectins in animals. Vet Immunol Immunopathol 2005; 108:97-110. [PMID: 16098608 DOI: 10.1016/j.vetimm.2005.07.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Collagenous lectins such as mannan-binding lectins (MBLs), ficolins (FCNs), surfactant proteins A and D (SP-A, SP-D), conglutinin (CG), and related ruminant lectins are multimeric proteins with carbohydrate-binding domains aligned in a manner that facilitates binding to microbial surface polysaccharides. MBLs and FCNs are structurally related to C1q, but activate the lectin complement pathway via interaction with MBL-associated serine proteases (MASPs). MBLs, FCNs, and other collagenous lectins also bind to some host macromolecules and contribute to their removal. While there is evidence that some lectins and the lectin complement pathway are conserved in vertebrates, many differences in collagenous lectins have been observed among humans, rodents, and other vertebrates. For example, humans have only one MBL but three FCNs, whereas most other species express two FCNs and two MBLs. Bovidae express CG and other SP-D-related collectins that are not found in monogastric species. Some dysfunctions of human MBL are due to single nucleotide polymorphisms (SNPs) that affect its expression or structure and thereby increase susceptibility to some infections. Collagenous lectins have well-established roles in innate immunity to various microorganisms, so it is possible that some lectin genotypes or induced phenotypes influence resistance to some infectious or inflammatory diseases in animals.
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Affiliation(s)
- Brandon N Lillie
- Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, Ont., Canada N1G 2W1
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27
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Hogenkamp A, van Eijk M, van Dijk A, van Asten AJAM, Veldhuizen EJA, Haagsman HP. Characterization and expression sites of newly identified chicken collectins. Mol Immunol 2005; 43:1604-16. [PMID: 16289291 DOI: 10.1016/j.molimm.2005.09.015] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2005] [Accepted: 09/24/2005] [Indexed: 11/17/2022]
Abstract
Collectins are members of the family of vertebrate C-type lectins. They have been found almost exclusively in mammals, with the exception of chicken MBL. Because of their important role in innate immunity, we sought to identify other collectins in chicken. Using the amino acid sequences of known collectins, the EST database was searched and related to the chicken genome. Three chicken collectins were found and designated chicken Collectin 1 (cCL-1), chicken Collectin 2 (cCL-2), and chicken Collectin 3 (cCL-3), which resemble the mammalian proteins Collectin Liver 1, Collectin 11 and Collectin Placenta 1, respectively. Additionally, a lectin was found which resembled Surfactant Protein A, but lacked the collagen domain. Therefore, it was named chicken Lung Lectin (cLL). Tissue distribution analysis showed cCL-1, cCL-2 and cCL-3 are expressed in a wide range of tissues throughout the digestive, the reproductive and the lymphatic system. Similar to SP-A, cLL is mainly localized in lung tissue. Phylogenetic analysis indicates that cCL-1, cCL-2 and cCL-3 represent new subgroups within the collectin family. The newly found collectins may have an important function in avian host defence. Elucidation of the role of these pattern-recognition molecules could lead to strategies that thwart infectious diseases in poultry, which could also be beneficial for public health.
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Affiliation(s)
- Astrid Hogenkamp
- Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Graduate School of Animal Health, Utrecht University, P.O. Box 80.165, 3508 TD Utrecht, The Netherlands
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Haczku A. Role and regulation of lung collectins in allergic airway sensitization. Pharmacol Ther 2005; 110:14-34. [PMID: 16226313 DOI: 10.1016/j.pharmthera.2005.08.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2005] [Accepted: 08/23/2005] [Indexed: 12/21/2022]
Abstract
Inhalation of allergens in atopic patients results in a characteristic inflammatory response while in normal, healthy individuals it elicits no symptoms. The mechanisms by which the pulmonary immune system accomplishes elimination of inhaled particles and suppression of the ensuing inflammatory response are poorly understood. Based on their structural uniqueness, specific localization and functional versatility the hydrophilic surfactant proteins [surfactant protein (SP)-A and SP-D] are important candidate regulators of these processes. Recent studies in our laboratory and others indicated significant changes in levels of these molecules during the asthmatic response in animal models as well as in asthmatic patients. Because of their capability to directly inhibit T-cell activation and T-cell-dependent allergic inflammatory events, SP-A and SP-D may be significant contributors to the local control of T-helper (Th)2-type inflammation in the airways. This review will discuss their relevant structural-functional features and recent evidence supporting the hypothesis that SP-A and SP-D have a role in regulation of allergic airway sensitization.
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Affiliation(s)
- Angela Haczku
- Pulmonary, Allergy and Critical Care Division, Department of Medicine, University of Pennsylvania School of Medicine, 421 Curie Boulevard, BRB II/III #840, Philadelphia, 19104-6061, USA.
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Crouch E, Tu Y, Briner D, McDonald B, Smith K, Holmskov U, Hartshorn K. Ligand specificity of human surfactant protein D: expression of a mutant trimeric collectin that shows enhanced interactions with influenza A virus. J Biol Chem 2005; 280:17046-56. [PMID: 15711012 DOI: 10.1074/jbc.m413932200] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Surfactant protein D is a pattern recognition molecule that plays diverse roles in immune regulation and anti-microbial host defense. Its interactions with known ligands are calcium-dependent and involve binding to the trimeric, C-type carbohydrate recognition domain. Surfactant protein D preferentially binds to glucose and related sugars. However, CL-43, a bovine serum lectin, which evolved through duplication of the surfactant protein D gene in ruminants, prefers mannose and mannose-rich polysaccharides. Surfactant protein D is characterized by two relatively conserved motifs at the binding face, along the edges of the shallow carbohydrate-binding groove. For CL-43, sequence alignments demonstrate a basic insertion, Arg-Ala-Lys (RAK), immediately N-terminal to the first motif. We hypothesized that this insertion contributes to the differences in saccharide selectivity and host defense function and compared the activities of recombinant trimeric neck + carbohydrate recognition domains of human surfactant protein D (NCRD) with CL-43 (RCL-43-NCRD) and selected NCRD mutants. Insertion of the CL-43 RAK sequence or a control Ala-Ala-Ala sequence (AAA) into the corresponding position in NCRD increased the efficiency of binding to mannan and changed the inhibitory potencies of competing saccharides to more closely resemble those of CL-43. In addition, RAK resembled CL-43 in its greater capacity to inhibit the infectivity of influenza A virus and to increase uptake of influenza by neutrophils.
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Affiliation(s)
- Erika Crouch
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
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30
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Sánchez-Barbero F, Strassner J, García-Cañero R, Steinhilber W, Casals C. Role of the degree of oligomerization in the structure and function of human surfactant protein A. J Biol Chem 2004; 280:7659-70. [PMID: 15615713 DOI: 10.1074/jbc.m410266200] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The role of the degree of oligomerization in the structure and function of human surfactant protein A (SP-A) was investigated using a human SP-A1 mutant (SP-A1(DeltaAVC,C6S)), expressed in mammalian cells, resulting from site-directed substitution of serine for Cys(6) and substitution of a functional signal peptide for the cysteine-containing SP-A signal sequence. This Cys(6) mutant lacked the NH(2)-terminal Ala(-3)-Val(-2)-Cys(-1) (DeltaAVC) extension present in some SP-A1 isoforms. SP-A1(DeltaAVC,C6S) was assembled exclusively as trimers as detected by electron microscopy and size exclusion chromatography. Trimeric SP-A1(DeltaAVC,C6S) was compared with supratrimeric SP-A1, which is structurally and functionally comparable to the octadecameric protein isolated from human lung lavages. SP-A1(DeltaAVC,C6S) showed reduced thermal stability of the collagen domain, studied by circular dichroism, and increased susceptibility to trypsin degradation. The T(m) was 32.7 degrees C for SP-A1(DeltaAVC,C6S) and 44.5 degrees C for SP-A1. Although SP-A1(DeltaAVC,C6S) was capable of binding to calcium, rough lipopolysaccharide, and phospholipid vesicles, this mutant was unable to induce rough lipopolysaccharide and phospholipid vesicle aggregation, to enhance the interfacial adsorption of SP-B/SP-C-surfactant membranes, and to undergo self-association in the presence of Ca(2+). On the other hand, the lack of supratrimeric assembly hardly affected the ability of SP-A1(DeltaAVC,C6S) to inhibit the production of tumor necrosis factor-alpha by macrophage-like U937 cells stimulated with either smooth or rough lipopolysaccharide. We conclude that supratrimeric assembly of human SP-A is essential for collagen triple helix stability at physiological temperatures, protection against proteases, protein self-association, and SP-A-induced ligand aggregation. The supratrimeric assembly is not essential for the binding of SP-A to ligands and anti-inflammatory effects of SP-A.
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Affiliation(s)
- Fernando Sánchez-Barbero
- Department of Biochemistry and Molecular Biology I, Complutense University of Madrid, 28040 Madrid, Spain
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31
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Abstract
Collectins are a family of collagenous calcium-dependent defense lectins in animals. Their polypeptide chains consist of four regions: a cysteine-rich N-terminal domain, a collagen-like region, an alpha-helical coiled-coil neck domain and a C-terminal lectin or carbohydrate-recognition domain. These polypeptide chains form trimers that may assemble into larger oligomers. The best studied family members are the mannan-binding lectin, which is secreted into the blood by the liver, and the surfactant proteins A and D, which are secreted into the pulmonary alveolar and airway lining fluid. The collectins represent an important group of pattern recognition molecules, which bind to oligosaccharide structures and/or lipid moities on the surface of microorganisms. They bind preferentially to monosaccharide units of the mannose type, which present two vicinal hydroxyl groups in an equatorial position. High-affinity interactions between collectins and microorganisms depend, on the one hand, on the high density of the carbohydrate ligands on the microbial surface, and on the other, on the degree of oligomerization of the collectin. Apart from binding to microorganisms, the collectins can interact with receptors on host cells. Binding of collectins to microorganisms may facilitate microbial clearance through aggregation, complement activation, opsonization and activation of phagocytosis, and inhibition of microbial growth. In addition, the collectins can modulate inflammatory and allergic responses, affect apoptotic cell clearance and modulate the adaptive immune system.
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Affiliation(s)
- J Koenraad van de Wetering
- Department of Biochemistry and Cell Biology, Graduate School of Animal Health, Faculty of Veterinary Medicine, Utrecht University, the Netherlands
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32
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Abstract
Ficolin is a plasma lectin, consisting of a short N-terminal multimerization domain, a middle collagen domain, and a C-terminal fibrinogen-like domain. The collagen domains assemble the subunits into trimers, and the N-terminal domain assembles four trimers into 12-mers. Two cysteine residues in the N-terminal domain are thought to mediate multimerization by disulfide bonding. We have generated three mutants of ficolin alpha in which the N-terminal cysteines were substituted by serines (Cys4, Cys24, and Cys4/Cys24). The N-terminal cysteine mutants were produced in a mammalian cell expression system, purified by affinity chromatography, and analyzed under nondenaturing conditions to resolve the multimer structure of the native protein and under denaturing conditions to resolve the disulfide-linked structure. Glycerol gradient sedimentation and electron microscopy in nondenaturing conditions showed that plasma and recombinant wild-type protein formed 12-mers. The Cys4 mutant also formed 12-mers, but Cys24 and Cys4/Cys24 mutants formed only trimers. This means that protein interfaces containing Cys4 are stable as noncovalent protein-protein interactions and do not require disulfides, whereas those containing Cys24-Cys24 require the disulfides for stability. Proteins were also analyzed by nonreducing SDS-PAGE to show the covalent structure under denaturing conditions. Wild-type ficolin was covalently linked into 12-mers, whereas elimination of either Cys4 or Cys24 gave dimers and monomers. We present a model in which symmetric Cys24-Cys24 disulfide bonds between trimers are the basis for multimerization. The model may also be relevant to collectin multimers.
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Affiliation(s)
- Tomoo Ohashi
- Department of Cell Biology, Duke University Medical Center, Durham, North Carolina 27710, USA
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Head JF, Mealy TR, McCormack FX, Seaton BA. Crystal structure of trimeric carbohydrate recognition and neck domains of surfactant protein A. J Biol Chem 2003; 278:43254-60. [PMID: 12913002 DOI: 10.1074/jbc.m305628200] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Surfactant protein A (SP-A), one of four proteins associated with pulmonary surfactant, binds with high affinity to alveolar phospholipid membranes, positioning the protein at the first line of defense against inhaled pathogens. SP-A exhibits both calcium-dependent carbohydrate binding, a characteristic of the collectin family, and specific interactions with lipid membrane components. The crystal structure of the trimeric carbohydrate recognition domain and neck domain of SP-A was solved to 2.1-A resolution with multiwavelength anomalous dispersion phasing from samarium. Two metal binding sites were identified, one in the highly conserved lectin site and the other 8.5 A away. The interdomain carbohydrate recognition domain-neck angle is significantly less in SP-A than in the homologous collectins, surfactant protein D, and mannose-binding protein. This conformational difference may endow the SP-A trimer with a more extensive hydrophobic surface capable of binding lipophilic membrane components. The appearance of this surface suggests a putative binding region for membrane-derived SP-A ligands such as phosphatidylcholine and lipid A, the endotoxic lipid component of bacterial lipopolysaccharide that mediates the potentially lethal effects of Gram-negative bacterial infection.
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Affiliation(s)
- James F Head
- Department of Physiology and Biophysics, Boston University School of Medicine, Boston, Massachusetts 02118, USA
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McAlinden A, Smith TA, Sandell LJ, Ficheux D, Parry DAD, Hulmes DJS. Alpha-helical coiled-coil oligomerization domains are almost ubiquitous in the collagen superfamily. J Biol Chem 2003; 278:42200-7. [PMID: 12920133 DOI: 10.1074/jbc.m302429200] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Alpha-helical coiled-coils are widely occurring protein oligomerization motifs. Here we show that most members of the collagen superfamily contain short, repeating heptad sequences typical of coiled coils. Such sequences are found at the N-terminal ends of the C-propeptide domains in all fibrillar procollagens. When fused C-terminal to a reporter molecule containing a collagen-like sequence that does not spontaneously trimerize, the C-propeptide heptad repeats induced trimerization. C-terminal heptad repeats were also found in the oligomerization domains of the multiplexins (collagens XV and XVIII). N-terminal heptad repeats are known to drive trimerization in transmembrane collagens, whereas fibril-associated collagens with interrupted triple helices, as well as collagens VII, XIII, XXIII, and XXV, were found to contain heptad repeats between collagen domains. Finally, heptad repeats were found in the von Willebrand factor A domains known to be involved in trimerization of collagen VI, as well as in collagen VII. These observations suggest that coiled-coil oligomerization domains are widely used in the assembly of collagens and collagen-like proteins.
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Affiliation(s)
- Audrey McAlinden
- Department of Orthopedic Surgery, Washington University School of Medicine, Barnes-Jewish Hospital, St. Louis, MO 63110, USA
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35
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McAlinden A, Crouch EC, Bann JG, Zhang P, Sandell LJ. Trimerization of the amino propeptide of type IIA procollagen using a 14-amino acid sequence derived from the coiled-coil neck domain of surfactant protein D. J Biol Chem 2002; 277:41274-81. [PMID: 12194968 DOI: 10.1074/jbc.m202257200] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The folding of a collagen triple helix usually requires the presence of additional sequences that contribute to the association and correct alignment of the collagen chains. We recently reported that the C-terminal neck and lectin domains of a collagenous C-type lectin, rat pulmonary surfactant protein D (SP-D), are sufficient to drive the trimerization of a heterologous type IIA procollagen amino propeptide sequence. However, the conformation of the resulting trimeric IIA propeptide and the specific contributions of the SP-D sequence to trimerization were not elucidated. In the present study, we show that trimerization of the fusion protein is associated with correct folding of the collagen helix within the IIA propeptide domain (as assessed by circular dichroism) and that the constituent chains are hydroxylated. Chemical cross-linking and analytical ultracentrifugation showed that the IIA amino-propeptide retains its trimeric configuration even after proteolytic removal of the SP-D domains. By contrast, IIA amino-propeptides synthesized without fusion to the neck or lectin domains are assembled exclusively as monomers. To localize the trimerization sequence, mutant chimeric cDNA constructs were designed containing premature termination codons within the coiled-coil neck domain. A short, 14-amino acid sequence corresponding to the first two heptad repeats of the neck domain was sufficient to drive the trimeric association of the IIA amino-propeptide alpha-chains. However, deletion of the collagen domain resulted in the secretion of monomers. These studies demonstrate that two heptad repeats are sufficient for trimeric association of the propeptide but indicate that cooperative interactions between the coiled-coil and collagen domains are required for the formation of a stable helix.
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Affiliation(s)
- Audrey McAlinden
- Department of Orthopaedic Surgery, Washington University School of Medicine at Barnes-Jewish Hospital, 660 South Euclid Avenue, St. Louis, MO 63110, USA
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Takahara K, Omatsu Y, Yashima Y, Maeda Y, Tanaka S, Iyoda T, Clausen BE, Matsubara K, Letterio J, Steinman RM, Matsuda Y, Inaba K, Clusen B. Identification and expression of mouse Langerin (CD207) in dendritic cells. Int Immunol 2002; 14:433-44. [PMID: 11978773 DOI: 10.1093/intimm/14.5.433] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We have cloned the mouse homologue of human Langerin (h-Langerin), a type II transmembrane protein with a single external C-type lectin domain. Mouse Langerin (m-Langerin) displays 65 and 74% homologies in total amino acid and lectin domains with those of h-Langerin. The cognate mouse and rat genes were assigned to chromosome 6D1-D2 and chromosome 4q33 distal-q34.1 proximal respectively, syntenic to the h-Langerin gene on chromosome 2p13. With RT-PCR, m-Langerin transcripts were as expected detected in MHC class II+, but not MHC class II-, cells from epidermis and the expression level was reduced by culture. However, m-Langerin transcripts were also expressed in spleen, lymph nodes (LN), thymus, liver, lung and even heart, but not gut-associated lymphoid tissues. In single-cell lymphoid suspensions, m-Langerin transcripts were mainly detected in the CD11c+ dendritic cells (DC), especially the CD11blow/CD8high fraction of spleen and LN. DC generated from bone marrow precursors by granulocyte macrophage colony stimulating factor (GM-CSF) expressed m-Langerin, but this was shut down during maturation with CD40 ligand or lipopolysaccharide. DC derived from blood monocytes by GM-CSF + IL-4 lacked m-Langerin unless the cultures were supplemented with transforming growth factor (TGF)-beta1. Unexpectedly, significant amounts of m-Langerin transcripts were detected in skin and LN of TGF-beta1-deficient mice, although in much lower amounts than littermate controls. Recombinant m-Langerin could form multimers and bind to mannan-agarose. These findings indicate that Langerin expression is regulated at several levels: by TGF-beta1, DC subsets, DC maturation and the tissue environment.
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MESH Headings
- Amino Acid Sequence
- Amino Acid Substitution
- Animals
- Antigens, CD
- Antigens, Surface/biosynthesis
- Antigens, Surface/chemistry
- Antigens, Surface/genetics
- Bone Marrow Cells/metabolism
- Cells, Cultured
- Chromosome Mapping
- Dendritic Cells/metabolism
- Down-Regulation
- Female
- Humans
- Lectins, C-Type
- Male
- Mannans/metabolism
- Mannose-Binding Lectins
- Mice
- Mice, Inbred BALB C
- Mice, Inbred DBA
- Models, Genetic
- Molecular Sequence Data
- Protein Structure, Tertiary
- Sequence Alignment
- Transcription, Genetic
- Transforming Growth Factor beta/metabolism
- Transforming Growth Factor beta1
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Affiliation(s)
- Kazuhiko Takahara
- Laboratory of Immunobiology, Department of Animal Development and Physiology, Division of Systemic Life Science, Graduate School of Biostudies, Kyoto University, 606-8502, Japan
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37
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Fukui N, McAlinden A, Zhu Y, Crouch E, Broekelmann TJ, Mecham RP, Sandell LJ. Processing of type II procollagen amino propeptide by matrix metalloproteinases. J Biol Chem 2002; 277:2193-201. [PMID: 11705992 DOI: 10.1074/jbc.m105485200] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In many embryonic tissues, type IIA procollagen is synthesized and deposited into the extracellular matrix containing the NH(2)-propeptide, the cysteine-rich domain of which binds to bone morphogenic proteins. To investigate whether matrix metalloproteinases (MMPs) synthesized during development and disease can cleave the NH(2) terminus of type II procollagens, we tested eight types of enzymes. Recombinant trimeric type IIA collagen NH(2)-propeptide encoded by exons 1-8 fused to the lectin domain of rat surfactant protein D was used as a substrate. The latter allowed trimerization of the propeptide domain and permitted isolation by saccharide affinity chromatography. Although MMPs 1, 2, and 8 did not show cleavage, MMPs 3, 7, 9, 13, and 14 cleaved the recombinant protein both at the telopeptide region and at the procollagen N-proteinase cleavage site. MMPs 7 and 13 demonstrated other cleavage sites in the type II collagen-specific region of the N-propeptide; MMP-7 had another cleavage site close to the COOH terminus of the cysteine-rich domain. To prove that an MMP can cleave the native type IIA procollagen in situ, we demonstrated that MMP-7 removes the NH(2)-propeptide from collagen fibrils in the extracellular matrix of fetal cartilage and identified the cleavage products. Because the N-proteinase and telopeptidase cleavage sites are present in both type IIA and type IIB procollagens and the telopeptide cleavage site is retained in the mature collagen fibril, this processing could be important to type IIB procollagen and to mature collagen fibrils as well.
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Affiliation(s)
- Naoshi Fukui
- Department of Orthopaedic Surgery, Barnes-Jewish Hospital at Washington University School of Medicine, St. Louis, Missouri 63110, USA
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