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Avcibas R, Vermul A, Gluhovic V, Boback N, Arroyo R, Kingma P, Isasi-Campillo M, Garcia-Ortega L, Griese M, Kuebler WM, Ochs M, Lauster D, Lopez-Rodriguez E. Multivalent, calcium-independent binding of surfactant protein A and D to sulfated glycosaminoglycans of the alveolar epithelial glycocalyx. Am J Physiol Lung Cell Mol Physiol 2024; 326:L524-L538. [PMID: 38375572 DOI: 10.1152/ajplung.00283.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 01/22/2024] [Accepted: 02/13/2024] [Indexed: 02/21/2024] Open
Abstract
Lung surfactant collectins, surfactant protein A (SP-A) and D (SP-D), are oligomeric C-type lectins involved in lung immunity. Through their carbohydrate recognition domain, they recognize carbohydrates at pathogen surfaces and initiate lung innate immune response. Here, we propose that they may also be able to bind to other carbohydrates present in typical cell surfaces, such as the alveolar epithelial glycocalyx. To test this hypothesis, we analyzed and quantified the binding affinity of SP-A and SP-D to different sugars and glycosaminoglycans (GAGs) by microscale thermophoresis (MST). In addition, by changing the calcium concentration, we aimed to characterize any consequences on the binding behavior. Our results show that both oligomeric proteins bind with high affinity (in nanomolar range) to GAGs, such as hyaluronan (HA), heparan sulfate (HS) and chondroitin sulfate (CS). Binding to HS and CS was calcium-independent, as it was not affected by changing calcium concentration in the buffer. Quantification of GAGs in bronchoalveolar lavage (BAL) fluid from animals deficient in either SP-A or SP-D showed changes in GAG composition, and electron micrographs showed differences in alveolar glycocalyx ultrastructure in vivo. Taken together, SP-A and SP-D bind to model sulfated glycosaminoglycans of the alveolar epithelial glycocalyx in a multivalent and calcium-independent way. These findings provide a potential mechanism for SP-A and SP-D as an integral part of the alveolar epithelial glycocalyx binding and interconnecting free GAGs, proteoglycans, and other glycans in glycoproteins, which may influence glycocalyx composition and structure.NEW & NOTEWORTHY SP-A and SP-D function has been related to innate immunity of the lung based on their binding to sugar residues at pathogen surfaces. However, their function in the healthy alveolus was considered as limited to interaction with surfactant lipids. Here, we demonstrated that these proteins bind to glycosaminoglycans present at typical cell surfaces like the alveolar epithelial glycocalyx. We propose a model where these proteins play an important role in interconnecting alveolar epithelial glycocalyx components.
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Affiliation(s)
- Rabia Avcibas
- Institute of Functional Anatomy, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Anna Vermul
- Institute of Functional Anatomy, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Vladimir Gluhovic
- Institute of Functional Anatomy, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Nico Boback
- Core Facility Electron Microscopy, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Raquel Arroyo
- Division of Neonatology and Pulmonary Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States
| | - Paul Kingma
- Division of Neonatology and Pulmonary Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States
| | - Miriam Isasi-Campillo
- Department of Biochemistry and Molecular Biology, Complutense University Madrid, Madrid, Spain
| | - Lucia Garcia-Ortega
- Department of Biochemistry and Molecular Biology, Complutense University Madrid, Madrid, Spain
| | - Matthias Griese
- Dr. von Hauner Children's Hospital, University Hospital, LMU Munich, German Center for Lung Research, Munich, Germany
| | - Wolfgang M Kuebler
- Institute of Physiology, Charité - Universitätsmedizin, Berlin, Germany
- German Center for Cardiovascular Research (DZHK), Berlin, Germany
- Keenan Research Centre, St. Michael's Hospital, University of Toronto, Toronto, Ontario, Canada
- Department of Surgery, University of Toronto, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- German Center for Lung Research (DZL), Berlin, Germany
| | - Matthias Ochs
- Institute of Functional Anatomy, Charité - Universitätsmedizin Berlin, Berlin, Germany
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- German Center for Lung Research (DZL), Berlin, Germany
- Core Facility Electron Microscopy, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Daniel Lauster
- Institute of Pharmacy, Biopharmaceuticals, Freie Universität Berlin, Berlin, Germany
| | - Elena Lopez-Rodriguez
- Institute of Functional Anatomy, Charité - Universitätsmedizin Berlin, Berlin, Germany
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Hallman M, Herting E. Historical perspective on surfactant therapy: Transforming hyaline membrane disease to respiratory distress syndrome. Semin Fetal Neonatal Med 2023; 28:101493. [PMID: 38030434 DOI: 10.1016/j.siny.2023.101493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2023]
Abstract
Lung surfactant is the first drug so far designed for the special needs of the newborn. In 1929, Von Neergard described lung hysteresis and proposed the role of surface forces. In 1955-1956, Pattle and Clements found direct evidence of lung surfactant. In 1959, Avery discovered that the airway's lining material was not surface-active in hyaline membrane disease (HMD). Patrick Bouvier Kennedy's death, among half-million other HMD-victims in 1963, stimulated surfactant research. The first large surfactant treatment trial failed in 1967, but by 1973, prediction of respiratory distress syndrome using surfactant biomarkers and promising data on experimental surfactant treatment were reported. After experimental studies on surfactant treatment provided insight in lung surfactant biology and pharmacodynamics, the first trials of surfactant treatment conducted in the 1980s showed a striking amelioration of severe HMD and its related deaths. In the 1990s, the first synthetic and natural surfactants were accepted for treatment of infants. Meta-analyses and further discoveries confirmed and extended these results. Surfactant development continues as a success-story of neonatal research.
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Affiliation(s)
- Mikko Hallman
- Medical Research Center, University of Oulu, and Oulu University Hospital, Oulu, Finland.
| | - Egbert Herting
- Department of Pediatrics, University of Lübeck, D-23562, Lübeck, Germany
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Liu JY, Pradhan SH, Hussain S, Sayes CM. Platform for Exposing Aerosolized Substances to Lung Surfactant and Alveolar Cells at the Air-Liquid Interface. ACS CHEMICAL HEALTH & SAFETY 2022. [DOI: 10.1021/acs.chas.2c00033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- James Y. Liu
- Department of Environmental Science, Baylor University, Waco, Texas 76706, United States
| | - Sahar H. Pradhan
- Department of Environmental Science, Baylor University, Waco, Texas 76706, United States
| | - Saber Hussain
- 711th Human Performance Wing, Air Force Research Laboratory, Dayton, Ohio 45435, United States
| | - Christie M. Sayes
- Department of Environmental Science, Baylor University, Waco, Texas 76706, United States
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4
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Mabrook M, Abd El-Aziz AM, Youssif M A, Hassan R. Inhibition of CL-11 reduces pulmonary inflammation in a mouse model of Klebsiella pneumoniae lung infection. Microb Pathog 2022; 164:105408. [PMID: 35063609 DOI: 10.1016/j.micpath.2022.105408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 01/08/2022] [Accepted: 01/13/2022] [Indexed: 11/24/2022]
Abstract
Infection caused by K. pneumoniae is associated with severe inflammation due to stimulation of the innate immune components including the complement system, which is the main player of the innate immune response. Excessive complement-mediated inflammation may cause severe lung injury. Here we clearly show that K. pneumoniae binds to different lectin pathway carbohydrate recognition molecules and activates the complement cascade via the LP. Administration of anti-CL-11 antibodies 6 h before the infection impairs LP functional activity but it shows no effect on the survival time of mice infected with K. pneumoniae. Similarly, no significant difference in bacterial load in blood and lung tissues was observed between mice that received anti-CL-11 and control group treated with an isotype antibody. Interestingly, treatment of mice with anti-CL-11 prior to infection significantly improved histopathological changes and lung injury score induced by K. pneumoniae. Moreover, administration of anti-CL-11 reduced leukocytes infiltration into lung tissues and decreased the levels of the inflammatory mediators TNF-α, IL-6, and IL-1β in the infected mice. These findings indicate that inhibition of the LP could secure a significant level of protection against lung injury during the infection caused by K. pneumoniae.
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Affiliation(s)
- Maha Mabrook
- Department of Microbiology and Immunology, Faculty of Pharmacy, Mansoura University, Mansoura, 35516, Egypt
| | - Abeer M Abd El-Aziz
- Department of Microbiology and Immunology, Faculty of Pharmacy, Mansoura University, Mansoura, 35516, Egypt
| | - Ali Youssif M
- Department of Microbiology and Immunology, Faculty of Pharmacy, Mansoura University, Mansoura, 35516, Egypt; Department of Veterinary Medicine, School of Biological Sciences, University of Cambridge, Cambridge, United Kingdom.
| | - Ramadan Hassan
- Department of Microbiology and Immunology, Faculty of Pharmacy, Mansoura University, Mansoura, 35516, Egypt
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5
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Floros J, Tsotakos N. Differential Regulation of Human Surfactant Protein A Genes, SFTPA1 and SFTPA2, and Their Corresponding Variants. Front Immunol 2021; 12:766719. [PMID: 34917085 PMCID: PMC8669794 DOI: 10.3389/fimmu.2021.766719] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2021] [Accepted: 11/02/2021] [Indexed: 11/26/2022] Open
Abstract
The human SFTPA1 and SFTPA2 genes encode the surfactant protein A1 (SP-A1) and SP-A2, respectively, and they have been identified with significant genetic and epigenetic variability including sequence, deletion/insertions, and splice variants. The surfactant proteins, SP-A1 and SP-A2, and their corresponding variants play important roles in several processes of innate immunity as well in surfactant-related functions as reviewed elsewhere [1]. The levels of SP-A have been shown to differ among individuals both under baseline conditions and in response to various agents or disease states. Moreover, a number of agents have been shown to differentially regulate SFTPA1 and SFTPA2 transcripts. The focus in this review is on the differential regulation of SFTPA1 and SFTPA2 with primary focus on the role of 5′ and 3′ untranslated regions (UTRs) and flanking sequences on this differential regulation as well molecules that may mediate the differential regulation.
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Affiliation(s)
- Joanna Floros
- Department of Pediatrics, The Pennsylvania State University College of Medicine, Hershey, PA, United States.,Department of Obstetrics and Gynecology, The Pennsylvania State University College of Medicine, Hershey, PA, United States
| | - Nikolaos Tsotakos
- School of Science, Engineering, and Technology, The Pennsylvania State University - Harrisburg, Middletown, PA, United States
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6
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Purification, Quantification, and Functional Analysis of Collectins. Methods Mol Biol 2020. [PMID: 32306318 DOI: 10.1007/978-1-0716-0430-4_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Native and recombinant collectins are purified by using mannan-agarose and an anti-collectin antibody column. The use of sandwich enzyme-linked immunosorbent assay (ELISA) with two antibodies against human mannan-binding lectin (MBL) enables elucidation of the collectin concentration in the blood, serum, and plasma. The collectin sugar specificity is demonstrated by determining the concentration of saccharide required to inhibit sugar binding by 50% in a saccharide-binding assay. Biological analyses including the complement-dependent hemolysis test and several other methods are used to evaluate collectin.
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7
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Watson A, Phipps MJS, Clark HW, Skylaris CK, Madsen J. Surfactant Proteins A and D: Trimerized Innate Immunity Proteins with an Affinity for Viral Fusion Proteins. J Innate Immun 2018; 11:13-28. [PMID: 30293076 PMCID: PMC6738215 DOI: 10.1159/000492974] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 08/16/2018] [Indexed: 12/20/2022] Open
Abstract
Innate recognition of viruses is an essential part of the immune response to viral pathogens. This is integral to the maintenance of healthy lungs, which are free from infection and efficient at gaseous exchange. An important component of innate immunity for identifying viruses is the family of C-type collagen-containing lectins, also known as collectins. These secreted, soluble proteins are pattern recognition receptors (PRRs) which recognise pathogen-associated molecular patterns (PAMPs), including viral glycoproteins. These innate immune proteins are composed of trimerized units which oligomerise into higher-order structures and facilitate the clearance of viral pathogens through multiple mechanisms. Similarly, many viral surface proteins form trimeric configurations, despite not showing primary protein sequence similarities across the virus classes and families to which they belong. In this review, we discuss the role of the lung collectins, i.e., surfactant proteins A and D (SP-A and SP-D) in viral recognition. We focus particularly on the structural similarity and complementarity of these trimeric collectins with the trimeric viral fusion proteins with which, we hypothesise, they have elegantly co-evolved. Recombinant versions of these innate immune proteins may have therapeutic potential in a range of infectious and inflammatory lung diseases including anti-viral therapeutics.
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Affiliation(s)
- Alastair Watson
- Child Health, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, United Kingdom
| | - Maximillian J S Phipps
- Computational Chemistry, Chemistry, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton, United Kingdom
| | - Howard W Clark
- Child Health, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, United Kingdom.,Institute for Life Sciences, University of Southampton, Southampton, United Kingdom.,National Institute for Health Research, Southampton Respiratory Biomedical Research Unit, Southampton Centre for Biomedical Research, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom
| | - Chris-Kriton Skylaris
- Computational Chemistry, Chemistry, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton, United Kingdom
| | - Jens Madsen
- Child Health, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, United .,Institute for Life Sciences, University of Southampton, Southampton, United .,National Institute for Health Research, Southampton Respiratory Biomedical Research Unit, Southampton Centre for Biomedical Research, University Hospital Southampton NHS Foundation Trust, Southampton, United
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8
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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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10
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Sorensen GL. Surfactant Protein D in Respiratory and Non-Respiratory Diseases. Front Med (Lausanne) 2018; 5:18. [PMID: 29473039 PMCID: PMC5809447 DOI: 10.3389/fmed.2018.00018] [Citation(s) in RCA: 111] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 01/19/2018] [Indexed: 12/16/2022] Open
Abstract
Surfactant protein D (SP-D) is a multimeric collectin that is involved in innate immune defense and expressed in pulmonary, as well as non-pulmonary, epithelia. SP-D exerts antimicrobial effects and dampens inflammation through direct microbial interactions and modulation of host cell responses via a series of cellular receptors. However, low protein concentrations, genetic variation, biochemical modification, and proteolytic breakdown can induce decomposition of multimeric SP-D into low-molecular weight forms, which may induce pro-inflammatory SP-D signaling. Multimeric SP-D can decompose into trimeric SP-D, and this process, and total SP-D levels, are partly determined by variation within the SP-D gene, SFTPD. SP-D has been implicated in the development of respiratory diseases including respiratory distress syndrome, bronchopulmonary dysplasia, allergic asthma, and chronic obstructive pulmonary disease. Disease-induced breakdown or modifications of SP-D facilitate its systemic leakage from the lung, and circulatory SP-D is a promising biomarker for lung injury. Moreover, studies in preclinical animal models have demonstrated that local pulmonary treatment with recombinant SP-D is beneficial in these diseases. In recent years, SP-D has been shown to exert antimicrobial and anti-inflammatory effects in various non-pulmonary organs and to have effects on lipid metabolism and pro-inflammatory effects in vessel walls, which enhance the risk of atherosclerosis. A common SFTPD polymorphism is associated with atherosclerosis and diabetes, and SP-D has been associated with metabolic disorders because of its effects in the endothelium and adipocytes and its obesity-dampening properties. This review summarizes and discusses the reported genetic associations of SP-D with disease and the clinical utility of circulating SP-D for respiratory disease prognosis. Moreover, basic research on the mechanistic links between SP-D and respiratory, cardiovascular, and metabolic diseases is summarized. Perspectives on the development of SP-D therapy are addressed.
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Affiliation(s)
- Grith L Sorensen
- Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
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11
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Madan T. Recombinant Fragment of Human Surfactant Protein D: A Hierarchical Regulator of Pulmonary Hypersensitivity. Am J Respir Crit Care Med 2017; 196:1495-1496. [DOI: 10.1164/rccm.201709-1934ed] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Taruna Madan
- Department of Innate ImmunityNational Institute for Research in Reproductive HealthMumbai, India
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12
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Ordonez SR, Veldhuizen EJA, van Eijk M, Haagsman HP. Role of Soluble Innate Effector Molecules in Pulmonary Defense against Fungal Pathogens. Front Microbiol 2017; 8:2098. [PMID: 29163395 PMCID: PMC5671533 DOI: 10.3389/fmicb.2017.02098] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 10/12/2017] [Indexed: 12/21/2022] Open
Abstract
Fungal infections of the lung are life-threatening but rarely occur in healthy, immunocompetent individuals, indicating efficient clearance by pulmonary defense mechanisms. Upon inhalation, fungi will first encounter the airway surface liquid which contains several soluble effector molecules that form the first barrier of defense against fungal infections. These include host defense peptides, like LL-37 and defensins that can neutralize fungi by direct killing of the pathogen, and collectins, such as surfactant protein A and D, that can aggregate fungi and stimulate phagocytosis. In addition, these molecules have immunomodulatory activities which can aid in fungal clearance from the lung. However, existing observations are based on in vitro studies which do not reflect the complexity of the lung and its airway surface liquid. Ionic strength, pH, and the presence of mucus can have strong detrimental effects on antifungal activity, while the potential synergistic interplay between soluble effector molecules is largely unknown. In this review, we describe the current knowledge on soluble effector molecules that contribute to antifungal activity, the importance of environmental factors and discuss the future directions required to understand the innate antifungal defense in the lung.
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Affiliation(s)
- Soledad R Ordonez
- Division of Molecular Host Defence, Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands
| | - Edwin J A Veldhuizen
- Division of Molecular Host Defence, Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands
| | - Martin van Eijk
- Division of Molecular Host Defence, Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands
| | - Henk P Haagsman
- Division of Molecular Host Defence, Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands
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13
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Aiyelabegan HT, Zaidi SSZ, Fanuel S, Eatemadi A, Ebadi MTK, Sadroddiny E. Albumin-based biomaterial for lung tissue engineering applications. INT J POLYM MATER PO 2016. [DOI: 10.1080/00914037.2016.1180610] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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14
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Sweeney S, Theodorou IG, Zambianchi M, Chen S, Gow A, Schwander S, Zhang JJ, Chung KF, Shaffer MSP, Ryan MP, Porter AE, Tetley TD. Silver nanowire interactions with primary human alveolar type-II epithelial cell secretions: contrasting bioreactivity with human alveolar type-I and type-II epithelial cells. NANOSCALE 2015; 7:10398-409. [PMID: 25996248 PMCID: PMC4765325 DOI: 10.1039/c5nr01496d] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Inhaled nanoparticles have a high deposition rate in the alveolar units of the deep lung. The alveolar epithelium is composed of type-I and type-II epithelial cells (ATI and ATII respectively) and is bathed in pulmonary surfactant. The effect of native human ATII cell secretions on nanoparticle toxicity is not known. We investigated the cellular uptake and toxicity of silver nanowires (AgNWs; 70 nm diameter, 1.5 μm length) with human ATI-like cells (TT1), in the absence or presence of Curosurf® (a natural porcine pulmonary surfactant with a low amount of protein) or harvested primary human ATII cell secretions (HAS; containing both the complete lipid as well as the full protein complement of human pulmonary surfactant i.e. SP-A, SP-B, SP-C and SP-D). We hypothesised that Curosurf® or HAS would confer improved protection for TT1 cells, limiting the toxicity of AgNWs. In agreement with our hypothesis, HAS reduced the inflammatory and reactive oxygen species (ROS)-generating potential of AgNWs with exposed TT1 cells. For example, IL-8 release and ROS generation was reduced by 38% and 29%, respectively, resulting in similar levels to that of the non-treated controls. However in contrast to our hypothesis, Curosurf® had no effect. We found a significant reduction in AgNW uptake by TT1 cells in the presence of HAS but not Curosurf. Furthermore, we show that the SP-A and SP-D are likely to be involved in this process as they were found to be specifically bound to the AgNWs. While ATI cells appear to be protected by HAS, evidence suggested that ATII cells, despite no uptake, were vulnerable to AgNW exposure (indicated by increased IL-8 release and ROS generation and decreased intracellular SP-A levels one day post-exposure). This study provides unique findings that may be important for the study of lung epithelial-endothelial translocation of nanoparticles in general and associated toxicity within the alveolar unit.
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Affiliation(s)
- Sinbad Sweeney
- Lung Cell Biology, Section of Pharmacology and Toxicology, Airways Disease, National Heart & Lung Institute, Imperial College London, London, UK.
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15
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Antunes E, Cruz CF, Azoia NG, Cavaco-Paulo A. The effects of solvent composition on the affinity of a peptide towards hair keratin: experimental and molecular dynamics data. RSC Adv 2015. [DOI: 10.1039/c4ra13901a] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Molecular dynamics simulations with a developed hair protofibril model demonstrated the ability to improve peptide uptake by hair shafts.
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Affiliation(s)
- Egipto Antunes
- CEB – Centre of Biological Engineering
- University of Minho
- 4710-057 Braga
- Portugal
| | - Célia F. Cruz
- CEB – Centre of Biological Engineering
- University of Minho
- 4710-057 Braga
- Portugal
| | - Nuno G. Azoia
- CEB – Centre of Biological Engineering
- University of Minho
- 4710-057 Braga
- Portugal
| | - Artur Cavaco-Paulo
- CEB – Centre of Biological Engineering
- University of Minho
- 4710-057 Braga
- Portugal
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16
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Nishikiori H, Chiba H, Ariki S, Kuronuma K, Otsuka M, Shiratori M, Ikeda K, Watanabe A, Kuroki Y, Takahashi H. Distinct compartmentalization of SP-A and SP-D in the vasculature and lungs of patients with idiopathic pulmonary fibrosis. BMC Pulm Med 2014; 14:196. [PMID: 25488319 PMCID: PMC4293112 DOI: 10.1186/1471-2466-14-196] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Accepted: 11/20/2014] [Indexed: 12/17/2022] Open
Abstract
Background Surfactant proteins SP-A and SP-D are useful biomarkers in diagnosis, monitoring, and prognosis of idiopathic pulmonary fibrosis (IPF). Despite their high structural homology, their serum concentrations often vary in IPF patients. This retrospective study aimed to investigate distinct compartmentalization of SP-A and SP-D in the vasculature and lungs by bronchoalveolar lavage fluid (BALF)/serum analysis, hydrophilicity and immunohistochemistry. Methods We included 36 IPF patients, 18 sarcoidosis (SAR) patients and 20 healthy subjects. Low-speed centrifugal supernatants of BALF (Sup-1) were obtained from each subject. Sera were also collected from each patient. Furthermore, we separated Sup-1 of IPF patients into hydrophilic supernatant (Sup-2) and hydrophobic precipitate (Ppt) by high-speed centrifugation. We measured SP-A and SP-D levels of each sample with the sandwich ELISA technique. We analyzed the change of the BALF/serum level ratios of the two proteins in IPF patients and their hydrophilicity in BALF. The distribution in the IPF lungs was also examined by immunohistochemical staining. Results In BALF, SP-A levels were comparable between the groups; however, SP-D levels were significantly lower in IPF patients than in others. Although IPF reduced the BALF/serum level ratios of the two proteins, the change in concentration of SP-D was more evident than SP-A. This suggests a higher disease impact for SP-D. Regarding hydrophilicity, although more than half of the SP-D remained in hydrophilic fractions (Sup-2), almost all of the SP-A sedimented in the Ppt with phospholipids. Hydrophilicity suggests that SP-D migrates into the blood more easily than SP-A in IPF lungs. Immunohistochemistry revealed that SP-A was confined to thick mucus-filling alveolar space, whereas SP-D was often intravascular. This data also suggests that SP-D easily leaks into the bloodstream, whereas SP-A remains bound to surfactant lipids in the alveolar space. Conclusions The current study investigated distinct compartmentalization of SP-A and SP-D in the vasculature and lungs. Our results suggest that serum levels of SP-D could reflect pathological changes of the IPF lungs more incisively than those of SP-A.
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Affiliation(s)
| | - Hirofumi Chiba
- Department of Respiratory Medicine and Allergology, Sapporo Medical University School of Medicine, South-1 West-17, Chuo-ku, Sapporo 060-8556, Japan.
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17
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Keshi H, Sakamoto T, Kawai T, Ohtani K, Katoh T, Jang SJ, Motomura W, Yoshizaki T, Fukuda M, Koyama S, Fukuzawa J, Fukuoh A, Yoshida I, Suzuki Y, Wakamiya N. Identification and Characterization of a Novel Human Collectin CL-K1. Microbiol Immunol 2013; 50:1001-13. [PMID: 17179669 DOI: 10.1111/j.1348-0421.2006.tb03868.x] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Collectins are a family of C-type lectins with two characteristic structures, collagen like domains and carbohydrate recognition domains. They recognize carbohydrate antigens on microorganisms and act as host-defense. Here we report the cloning and characterization of a novel collectin CL-K1. RT-PCR analyses showed CL-K1 mRNA is present in all organs. The deduced amino acid sequence and the data from immunostaining of CL-K1 cDNA expressing CHO cells revealed that CL-K1 is expressed as a secreted protein. CL-K1 is found in blood by immunoblotting and partial amino acid analyses. CL-K1 showed Ca(2+)-dependent sugar binding activity of fucose and weakly mannose but not N-acetyl-galactosamine, N-acetyl-glucosamine, or maltose, though mannose-binding lectin (MBL) containing similar amino acid motif. CL-K1 can recognize specially several bacterial saccharides due to specific sugar-binding character. Elucidation of the role of two ancestor collectins of CL-K1 and CL-L1 could lead to see the biological function of collectin family.
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Affiliation(s)
- Hiroyuki Keshi
- Research & Development Center, Fuso Pharmaceutical Industries, Osaka, Osaka, Japan
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Hernansanz-Agustín P, Izquierdo-Álvarez A, García-Ortiz A, Ibiza S, Serrador JM, Martínez-Ruiz A. Nitrosothiols in the immune system: signaling and protection. Antioxid Redox Signal 2013; 18:288-308. [PMID: 22746191 PMCID: PMC3518543 DOI: 10.1089/ars.2012.4765] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
SIGNIFICANCE In the immune system, nitric oxide (NO) has been mainly associated with antibacterial defenses exerted through oxidative, nitrosative, and nitrative stress and signal transduction through cyclic GMP-dependent mechanisms. However, S-nitrosylation is emerging as a post-translational modification (PTM) involved in NO-mediated cell signaling. RECENT ADVANCES Precise roles for S-nitrosylation in signaling pathways have been described both for innate and adaptive immunity. Denitrosylation may protect macrophages from their own S-nitrosylation, while maintaining nitrosative stress compartmentalized in the phagosomes. Nitrosothiols have also been shown to be beneficial in experimental models of autoimmune diseases, mainly through their role in modulating T-cell differentiation and function. CRITICAL ISSUES Relationship between S-nitrosylation, other thiol redox PTMs, and other NO-signaling pathways has not been always taken into account, particularly in the context of immune responses. Methods for assaying S-nitrosylation in individual proteins and proteomic approaches to study the S-nitrosoproteome are constantly being improved, which helps to move this field forward. FUTURE DIRECTIONS Integrated studies of signaling pathways in the immune system should consider whether S-nitrosylation/denitrosylation processes are among the PTMs influencing the activity of key signaling and adaptor proteins. Studies in pathophysiological scenarios will also be of interest to put these mechanisms into broader contexts. Interventions modulating nitrosothiol levels in autoimmune disease could be investigated with a view to developing new therapies.
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Affiliation(s)
- Pablo Hernansanz-Agustín
- Servicio de Inmunología, Hospital Universitario de La Princesa, Instituto de Investigación Sanitaria Princesa (IP), Madrid, Spain
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Biological functions of the novel collectins CL-L1, CL-K1, and CL-P1. J Biomed Biotechnol 2012; 2012:493945. [PMID: 22570530 PMCID: PMC3336186 DOI: 10.1155/2012/493945] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2011] [Revised: 02/13/2012] [Accepted: 02/14/2012] [Indexed: 12/17/2022] Open
Abstract
Collectins are characterized by a collagen-like sequence and a carbohydrate recognition domain and are members of the vertebrate C-type lectin superfamily. Recently, “novel collectins”, different from “classical collectins” consisting of mannan-binding lectin (MBL) and surfactant proteins A and D (SP-A and SP-D), have been found by reverse genetics. These “novel collectins” consist of collectin liver 1 (CL-L1), collectin kidney 1 (CL-K1), and collectin placenta 1 (CL-P1) and are encoded by three separate genes. Experimental findings on human and animal collectins have shown that both novel collectins and classical collectins play an important role in innate immunity. Based on our recent results and those of others, in this paper, we summarize the new biological functions of these novel collectins in embryonic morphogenesis and development.
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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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Ngan DA, Wilcox PG, Aldaabil M, Li Y, Leipsic JA, Sin DD, Man SFP. The relationship of systemic inflammation to prior hospitalization in adult patients with cystic fibrosis. BMC Pulm Med 2012; 12:3. [PMID: 22333132 PMCID: PMC3312864 DOI: 10.1186/1471-2466-12-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2011] [Accepted: 02/14/2012] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND In cystic fibrosis (CF) patients, it has been suggested that systemic inflammation may be an important risk factor for poor health outcomes. The relationship of plasma inflammatory biomarkers to lung function and hospitalization history remains largely unexplored. METHODS This cross-sectional study included 58 consecutive, clinically stable adults from the CF Clinic at St. Paul's Hospital (Vancouver, Canada). Blood levels of interleukin (IL)-6, IL-1β, C-reactive protein (CRP), interleukin (IL)-6, IL-1β, granzyme B (GzmB), chemokine C-C motif ligand 18 (CCL18/PARC), surfactant protein D (SP-D), lipopolysaccharide (LPS)-binding protein, and soluble cluster of differentiation 14 (sCD14) were measured using enzyme-linked immunosorbent assays, and LPS levels were measured using a Limulus amebocyte lysate assay. Spirometry was also performed. Multivariable linear regression analysis was used to assess relationships of the blood biomarkers to lung function. RESULTS Lung function impairment was independently associated with elevated plasma levels of CRP (P < 0.01), IL-6 (P = 0.04), IL-1β (P < 0.01), and LBP (P < 0.01). Increasing age (P < 0.01), reduced body mass index (P = 0.02), prior hospitalizations (P = 0.03), and presence of Pseudomonas aeruginosa in sputum cultures (P < 0.01) were also associated with reduced lung function. Elevated concentrations of LPS in plasma were associated with a previous history of hospitalization (P < 0.05). There was a trend towards an increase in plasma IL-6 (P = 0.07) and IL-1β (P = 0.06) levels in patients who were previously hospitalized. CONCLUSIONS IL-6 and IL-1β are promising systemic biomarkers for lung function impairment and history of hospitalization in adult patients with CF.
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Affiliation(s)
- David A Ngan
- UBC James Hogg Research Centre, Institute for Heart + Lung Health at St, Paul's Hospital and Department of Medicine, University of British Columbia, Vancouver, BC, Canada
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22
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Fukuda M, Ohtani K, Jang SJ, Yoshizaki T, Mori KI, Motomura W, Yoshida I, Suzuki Y, Kohgo Y, Wakamiya N. Molecular cloning and functional analysis of scavenger receptor zebrafish CL-P1. Biochim Biophys Acta Gen Subj 2011; 1810:1150-9. [DOI: 10.1016/j.bbagen.2011.09.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2011] [Revised: 08/31/2011] [Accepted: 09/26/2011] [Indexed: 01/13/2023]
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23
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Yoshizaki T, Ohtani K, Motomura W, Jang SJ, Mori KI, Kitamoto N, Yoshida I, Suzuki Y, Wakamiya N. Comparison of human blood concentrations of collectin kidney 1 and mannan-binding lectin. J Biochem 2011; 151:57-64. [DOI: 10.1093/jb/mvr114] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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25
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Kim YU, Ohtani K, Mori K, Jang SJ, Suzuki Y, Wakamiya N. Gene regulation function of the three specificity protein-1 (Sp1) within the human collectin placenta-1 proximal promoter. Genes Genomics 2011. [DOI: 10.1007/s13258-011-0001-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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26
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Natural IgM and innate immune collectin SP-D bind to late apoptotic cells and enhance their clearance by alveolar macrophages in vivo. Mol Immunol 2010; 48:37-47. [DOI: 10.1016/j.molimm.2010.09.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2010] [Revised: 09/16/2010] [Accepted: 09/22/2010] [Indexed: 11/16/2022]
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27
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Schwab U, Rohde KH, Wang Z, Chess PR, Notter RH, Russell DG. Transcriptional responses of Mycobacterium tuberculosis to lung surfactant. Microb Pathog 2009; 46:185-93. [PMID: 19272305 PMCID: PMC2748912 DOI: 10.1016/j.micpath.2008.12.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2008] [Revised: 12/19/2008] [Accepted: 12/30/2008] [Indexed: 11/27/2022]
Abstract
This study uses microarray analyses to examine gene expression profiles for Mycobacterium tuberculosis (Mtb) induced by exposure in vitro to bovine lung surfactant preparations that vary in apoprotein content: (i) whole lung surfactant (WLS) containing the complete mixture of endogenous lipids and surfactant proteins (SP)-A, -B, -C, and -D; (ii) extracted lung surfactant (CLSE) containing lipids plus SP-B and -C; (iii) column-purified surfactant lipids (PPL) containing no apoproteins, and (iv) purified human SP-A. Exposure to WLS evoked a multitude of transcriptional responses in Mtb, with 52 genes up-regulated and 23 genes down-regulated at 30min exposure, plus 146 genes up-regulated and 27 genes down-regulated at 2h. Notably, WLS rapidly induced several membrane-associated lipases that presumptively act on surfactant lipids as substrates, and a large number of genes involved in the synthesis of phthiocerol dimycocerosate (PDIM), a cell wall component known to be important in macrophage interactions and Mtb virulence. Exposure of Mtb to CLSE, PPL, or purified SP-A caused a substantially weaker transcriptional response (=20 genes were induced) suggesting that interactions among multiple lipid-protein components of WLS may contribute to its effects on Mtb transcription.
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Affiliation(s)
- Ute Schwab
- Department of Microbiology and Immunology, Cornell University College of Veterinary Medicine, Ithaca, NY 14853, USA.
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28
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Snyder GD, Oberley-Deegan RE, Goss KL, Romig-Martin SA, Stoll LL, Snyder JM, Weintraub NL. Surfactant protein D is expressed and modulates inflammatory responses in human coronary artery smooth muscle cells. Am J Physiol Heart Circ Physiol 2008; 294:H2053-9. [PMID: 18359891 DOI: 10.1152/ajpheart.91529.2007] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Surfactant protein D (SP-D) is a constituent of the innate immune system that plays a role in the host defense against lung pathogens and in modulating inflammatory responses. While SP-D has been detected in extrapulmonary tissues, little is known about its expression and function in the vasculature. Immunostaining of human coronary artery tissue sections demonstrated immunoreactive SP-D protein in smooth muscle cells (SMCs) and endothelial cells. SP-D was also detected in isolated human coronary artery SMCs (HCASMCs) by PCR and immunoblot analysis. Treatment of HCASMCs with endotoxin (LPS) stimulated the release of IL-8, a proinflammatory cytokine. This release was inhibited >70% by recombinant SP-D. Overexpression of SP-D by adenoviral-mediated gene transfer in HCASMCs inhibited both LPS- and TNF-alpha-induced IL-8 release. Overexpression of SP-D also enhanced uptake of Chlamydia pneumoniae elementary bodies into HCASMCs while attenuating IL-8 production induced by bacterial exposure. Both LPS and TNF-alpha increased SP-D mRNA levels by five- to eightfold in HCASMCs, suggesting that inflammatory mediators upregulate the expression of SP-D. In conclusion, SP-D is expressed in human coronary arteries and functions as an anti-inflammatory protein in HCASMCs. SP-D may also participate in the host defense against pathogens that invade the vascular wall.
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Affiliation(s)
- Gary D Snyder
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, USA
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Hogenkamp A, Herías MV, Tooten PCJ, Veldhuizen EJA, Haagsman HP. Effects of surfactant protein D on growth, adhesion and epithelial invasion of intestinal Gram-negative bacteria. Mol Immunol 2007; 44:3517-27. [PMID: 17477970 DOI: 10.1016/j.molimm.2007.03.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2007] [Revised: 03/09/2007] [Accepted: 03/14/2007] [Indexed: 11/21/2022]
Abstract
Surfactant protein D (SP-D) interacts with various different microorganisms and plays an important role in pulmonary innate immunity. SP-D expression has also been detected in extrapulmonary tissues, including the gastro-intestinal tract. However, its function in the intestine is unknown and may differ considerably from SP-D functions in the lung. Therefore, the effects of porcine SP-D (pSP-D) on several strains of intestinal bacteria were studied by means of bacterial growth assays, colony-count assays, radial diffusion assays and differential fluorescent staining. Furthermore, the effect of pSP-D on the adhesion- and invasion-characteristics was investigated. All bacterial strains tested in this study were aggregated by pSP-D, but only Escherichia coli K12 was susceptible to pSP-D-mediated growth inhibition. Bacterial membrane integrity of E. coli K12 was affected by pSP-D, but this did not lead to a reduced bacterial viability. Therefore, it is unlikely that pSP-D has a direct antimicrobial effect, and the observed effects are most likely due to pSP-D-mediated bacterial aggregation. The effects of pSP-D on bacterial adhesion and invasion were studied with the porcine intestinal epithelial cell line IPI-2I. Preincubation with pSP-D results in a several-fold increase in adhesion (E. coli and Salmonella) and invasion (Salmonella), but did not affect the IL-8 production induced by the bacteria. Results obtained in this study suggest that pSP-D promotes uptake of pathogenic bacteria by epithelial cells. This may reflect a scavenger function for pSP-D in the intestine, which enables the host to generate a more rapid response to infectious bacteria.
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Affiliation(s)
- Astrid Hogenkamp
- Department of Infectious Diseases and Immunology, Division Molecular Host Defence, Graduate School of Animal Health, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
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Jensen PH, Laursen I, Matthiesen F, Højrup P. Posttranslational modifications in human plasma MBL and human recombinant MBL. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2007; 1774:335-44. [PMID: 17289451 DOI: 10.1016/j.bbapap.2006.12.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2006] [Revised: 11/10/2006] [Accepted: 12/21/2006] [Indexed: 10/23/2022]
Abstract
Mannan-binding lectin (MBL) is a complex serum protein that plays an important role in innate immunity. In addition to assuming several different oligomeric forms, the polypeptide itself is highly heterogeneous. This heterogeneity is due to post-translational modifications, which help to stabilize the intact protein in its active conformation. For the first time, positions and occupation frequency of partial hydroxylations and partial glycosylations are reported in MBL. Hydroxylation and glycosylation patterns of both recombinant and plasma derived MBL were determined, using a combination of mass spectrometry on reduced MBL and on enzyme cleaved MBL. Variations in the degree of hydroxylation and glycosylation seem to be an indigenous characteristic of collectins. In addition to these already known modifications, a new post-translational modification was identified. Cys(216) (and occasionally also Cys(202)) was modified in trace amounts to dehydroalanine, as detected by a 34 Da mass loss. This impairs the formation of a disulphide bond in the carbohydrate recognition domain. The dehydroalanine was identified in similar small amounts in both recombinant and plasma-derived MBL.
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Affiliation(s)
- Pia Hønnerup Jensen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
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31
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Sorensen GL, Husby S, Holmskov U. Surfactant protein A and surfactant protein D variation in pulmonary disease. Immunobiology 2007; 212:381-416. [PMID: 17544823 DOI: 10.1016/j.imbio.2007.01.003] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2006] [Accepted: 01/02/2007] [Indexed: 12/17/2022]
Abstract
Surfactant proteins A (SP-A) and D (SP-D) have been implicated in pulmonary innate immunity. The proteins are host defense lectins, belonging to the collectin family which also includes mannan-binding lectin (MBL). SP-A and SP-D are pattern-recognition molecules with the lectin domains binding preferentially to sugars on a broad spectrum of pathogen surfaces and thereby facilitating immune functions including viral neutralization, clearance of bacteria, fungi and apoptotic and necrotic cells, modulation of allergic reactions, and resolution of inflammation. SP-A and SP-D can interact with receptor molecules present on immune cells leading to enhanced microbial clearance and modulation of inflammation. SP-A and SP-D also modulate the functions of cells of the adaptive immune system including dendritic cells and T cells. Studies on SP-A and SP-D polymorphisms and protein levels in bronchoalveolar lavage and blood have indicated associations with a multitude of pulmonary inflammatory diseases. In addition, accumulating evidence in mouse models of infection and inflammation indicates that recombinant forms of the surfactant proteins are biologically active in vivo and may have therapeutic potential in controlling pulmonary inflammatory disease. The presence of the surfactant collectins, especially SP-D, in non-pulmonary tissues, such as the gastrointestinal tract and genital organs, suggest additional actions located to other mucosal surfaces. The aim of this review is to summarize studies on genetic polymorphisms, structural variants, and serum levels of human SP-A and SP-D and their associations with human pulmonary disease.
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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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Abstract
Surfactant proteins A and D (SP-A and SP-D) are members of the collectin family of host defense proteins that are expressed in epithelial cells lining the lung. SP-A and SP-D interact with surfactant lipids in complex ways to determine the structure of tubular myelin, and the ratio of surfactant subfractions that, in turn, influences surfactant uptake and metabolism, respectively. SP-A and SP-D play critical roles in host defense of the lung against diverse viral, fungal, and bacterial pathogens. The collectins bind to the surfaces of microbes via carbohydrate-dependent interaction, aggregating, opsonizing, and enhancing clearance of the organisms by alveolar macrophages in the lung. Pulmonary surfactant proteins A and D play dual roles in pulmonary homeostasis, determining the structure of alveolar lipids and mediating the innate host defense system of the lung.
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Affiliation(s)
- Jeffrey A Whitsett
- Cincinnati Children's Hospital Medical Center and University of Cincinnati College of Medicine, Cincinnati, Ohio 45229-3039, USA.
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Guttentag SH, Akhtar A, Tao JQ, Atochina E, Rusiniak ME, Swank RT, Bates SR. Defective surfactant secretion in a mouse model of Hermansky-Pudlak syndrome. Am J Respir Cell Mol Biol 2005; 33:14-21. [PMID: 15790974 PMCID: PMC2715302 DOI: 10.1165/rcmb.2004-0293oc] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Hermansky-Pudlak syndrome (HPS) in humans represents a family of disorders of lysosome-related organelle biogenesis associated with severe, progressive pulmonary disease. Human case reports and a mouse model of HPS, the pale ear/pearl mouse (ep/pe), exhibit giant lamellar bodies (GLB) in type II alveolar epithelial cells. We examined surfactant proteins and phospholipid from ep/pe mice to elucidate the process of GLB formation. The 2.8-fold enrichment of tissue phospholipids in ep/pe mice resulted from accumulation from birth through adulthood. Tissue surfactant protein (SP)-B and -C were increased in adult ep/pe mice compared with wild-type mice (WT), whereas SP-A and -D were not different. Large aggregate surfactant (LA) from adult ep/pe mice had decreased phospholipid, SP-B, and SP-C, with no differences in SP-A and -D compared with WT. Although LA from ep/pe animals exhibited an increased total protein-to-total phospholipid ratio compared with WT, surface tension was not compromised. Phospholipid secretion from isolated type II cells showed that basal and stimulated secretion from ep/pe cells were approximately 50% of WT cells. Together, our data indicate that GLB formation is not associated with abnormal trafficking or recycling of surfactant material. Instead, impaired secretion is an important component of GLB formation in ep/pe mice.
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Affiliation(s)
- Susan H Guttentag
- Division of Neonatology, Department of Pediatrics, Children's Hospital of Philadelphia, 19104-4318, USA.
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Heidinger K, König IR, Bohnert A, Kleinsteiber A, Hilgendorff A, Gortner L, Ziegler A, Chakraborty T, Bein G. Polymorphisms in the human surfactant protein-D (SFTPD) gene: strong evidence that serum levels of surfactant protein-D (SP-D) are genetically influenced. Immunogenetics 2005; 57:1-7. [PMID: 15700120 PMCID: PMC7100655 DOI: 10.1007/s00251-005-0775-5] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2004] [Revised: 12/23/2004] [Indexed: 11/30/2022]
Abstract
The collectin surfactant protein-D (SP-D) plays a significant role in innate immunity. Epidemiological studies described associations between single nucleotide polymorphisms (SNPs) of the human gene coding surfactant protein-D (SFTPD) and infectious pulmonary diseases. Studies on twins indicated very strong genetic dependence for serum levels of SP-D. The aim of this study was to determine the genetic influence of sequence variations within the SFTPD gene on the constitutional serum SP-D levels. We sequenced the 5′ untranslated region (5′UTR), the coding region and the 3′ region of the SFTPD gene of 32 randomly selected blood donors. Six validated SNPs were genotyped with sequence-specific probes (TaqMan 7000) in 290 German blood donors. Serum SP-D levels were analysed by ELISA, and the association of SFTPD haplotype estimates with the quantitative phenotype serum SP-D level was determined. One single SFTPD haplotype (allele frequency 13.53%) revealed a negative association with serum SP-D levels (P<0.0001). This was confirmed in a second prospectively collected group of blood donors (n=160, P=0.0034). The discovery of a frequent negative variant of the SFTPD gene provides a basis for genetic analysis of the function of SP-D in the resistance against pulmonary infections and inflammatory disorders in humans.
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Affiliation(s)
- Kathrin Heidinger
- Institute of Clinical Immunology and Transfusion Medicine, University of Giessen, Langhansstrasse 7, 35392, Giessen, Germany.
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Soerensen CM, Nielsen OL, Willis A, Heegaard PMH, Holmskov U. Purification, characterization and immunolocalization of porcine surfactant protein D. Immunology 2005; 114:72-82. [PMID: 15606797 PMCID: PMC1782063 DOI: 10.1111/j.1365-2567.2004.01999.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Surfactant protein D (SP-D) is a collectin believed to play an important role in innate immunity. SP-D is characterized by having a collagen-like domain and a carbohydrate recognition domain (CRD), which has a specific Ca(2+)-dependent specificity for saccharides and thus the ability to bind complex glycoconjugates on micro-organisms. This paper describes the tissue immunolocalization of porcine SP-D (pSP-D) in normal slaughter pigs using a monoclonal antibody raised against purified pSP-D. Porcine SP-D was purified from porcine bronchoalveolar lavage (BAL) by maltose-agarose and immunoglobulin M affinity chromatography. The purified protein appeared on sodium dodecyl sulphate-polyacrylamide gel electrophoresis as a band of approximately 53,000 MW in the reduced state and approximately 138,000 MW in the unreduced state. Porcine SP-D was sensitive to collagenase digestion and N-deglycosylation, which reduced the molecular mass to approximately 24,000 MW and approximately 48,000 MW respectively, in the reduced state. N-deglycosylation of the collagen-resistant fragment, reduced the molecular mass to approximately 21,000 MW showing the presence of an N-glycosylation site located in the CRD. Porcine SP-D bound to solid-phase mannan in a dose and Ca(2+)-dependent manner with a saccharide specificity similar to rat and human SP-D. The purified protein was used for the production of a monoclonal anti-pSP-D antibody. The antibody reacted specifically with pSP-D in the reduced and unreduced state when analysed by Western blotting. Immunohistochemical evaluation of normal porcine tissues showed pSP-D immunoreactivity predominantly in Clara cells and serous cells of the bronchial submucosal glands, and to a lesser extent in alveolar type II cells, epithelial cells of the intestinal glands (crypts of Lieberkuhn) in the duodenum, jejunum and ileum and serous cells of the dorsolateral lacrimal gland.
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Affiliation(s)
- C M Soerensen
- Department of Veterinary Pathobiology, Laboratory of Pathology, The Royal Veterinary Agricultural University, Ridebanevej 3, 1870 Frederiksberg, Denmark
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37
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Jensen PH, Weilguny D, Matthiesen F, McGuire KA, Shi L, Højrup P. Characterization of the oligomer structure of recombinant human mannan-binding lectin. J Biol Chem 2005; 280:11043-51. [PMID: 15653690 DOI: 10.1074/jbc.m412472200] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mannan-binding lectin (MBL) belongs to a family of proteins called the collectins, which show large differences in their ultrastructures. These differences are believed to be determined by different N-terminal disulfide-bonding patterns. So far only the bonding pattern of two of the simple forms (recombinant rat MBL-C and bovine CL-43) have been determined. Recombinant MBL expressed in human cells was purified, and the structure of the N-terminal region was determined. Preliminary results on human plasma-derived MBL revealed high similarity to the recombinant protein. Here we report the structure of the N-terminal part of recombinant human MBL and present a model to explain the oligomerization pattern. Using a strategy of consecutive enzymatic digestions and matrix-assisted laser desorption ionization mass spectrometry, we succeeded in identifying a number of disulfide-linked peptides from the N-terminal cysteine-rich region. Based on these building blocks, we propose a model that can explain the various oligomeric forms found in purified MBL preparations. Furthermore, the model was challenged by the production of cysteine to serine mutants of the three N-terminally situated cysteines. The oligomerization patterns of these mutants support the proposed model. The model indicates that the polypeptide dimer is the basic unit in the oligomerization.
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Affiliation(s)
- Pia H Jensen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
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38
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van de Wetering JK, van Remoortere A, Vaandrager AB, Batenburg JJ, van Golde LMG, Hokke CH, van Hellemond JJ. Surfactant protein D binding to terminal alpha1-3-linked fucose residues and to Schistosoma mansoni. Am J Respir Cell Mol Biol 2004; 31:565-72. [PMID: 15284077 DOI: 10.1165/rcmb.2004-0105oc] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Pulmonary surfactant protein (SP)-D is an important component of the innate immune system of the lung, which is thought to function by binding to specific carbohydrates on the surface of viruses and unicellular pathogens. SP-D has been shown to have a relatively high affinity for the monosaccharides mannose, glucose, and fucose. However, there is limited information on SP-D binding to complex carbohydrate structures, and binding of SP-D to fucose in the context of an oligosaccharide has not yet been investigated. In this study, we used surface plasmon resonance spectroscopy to examine the potential of SP-D to bind to various synthetic fucosylated oligosaccharides, and identified Fucalpha1-3GalNAc and Fucalpha1-3GlcNAc elements as strong ligands. These types of fucosylated glycoconjugates are presented at the surface of Schistosoma mansoni, a parasitic worm that, during development, transiently resides in the lung. In line with the findings by surface plasmon resonance, we found that SP-D can bind to larval stages of S. mansoni, demonstrating for the first time that SP-D interacts with multicellular lung pathogens.
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Affiliation(s)
- J Koenraad van de Wetering
- Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
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39
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Hirche TO, Crouch EC, Espinola M, Brokelman TJ, Mecham RP, DeSilva N, Cooley J, Remold-O'Donnell E, Belaaouaj A. Neutrophil Serine Proteinases Inactivate Surfactant Protein D by Cleaving within a Conserved Subregion of the Carbohydrate Recognition Domain. J Biol Chem 2004; 279:27688-98. [PMID: 15078883 DOI: 10.1074/jbc.m402936200] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.8] [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) plays important roles in innate immunity including the defense against bacteria, fungi, and respiratory viruses. Because SP-D specifically interacts with neutrophils that infiltrate the lung in response to acute inflammation and infection, we examined the hypothesis that the neutrophil-derived serine proteinases (NSPs): neutrophil elastase, proteinase-3, and cathepsin G degrade SP-D. All three human NSPs specifically cleaved recombinant rat and natural human SP-D dodecamers in a time- and dose-dependent manner, which was reciprocally dependent on calcium concentration. The NSPs generated similar, relatively stable, disulfide cross-linked immunoreactive fragments of approximately 35 kDa (reduced), and sequencing of a major catheptic fragment definitively localized the major sites of cleavage to a highly conserved subregion of the carbohydrate recognition domain. Cleavage markedly reduced the ability of SP-D to promote bacterial aggregation and to bind to yeast mannan in vitro. Incubation of SP-D with isolated murine neutrophils led to the generation of similar fragments, and cleavage was inhibited with synthetic and natural serine proteinase inhibitors. In addition, neutrophils genetically deficient in neutrophil elastase and/or cathepsin G were impaired in their ability to degrade SP-D. Using a mouse model of acute bacterial pneumonia, we observed the accumulation of SP-D at sites of neutrophil infiltration coinciding with the appearance of approximately 35-kDa SP-D fragments in bronchoalveolar lavage fluids. Together, our data suggest that neutrophil-derived serine proteinases cleave SP-D at sites of inflammation with potential deleterious effects on its biological functions.
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Affiliation(s)
- Tim O Hirche
- Department of Medicine, Washington University School of Medicine, Saint Louis, Missouri 63110, USA
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40
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van de Wetering JK, Coenjaerts FEJ, Vaandrager AB, van Golde LMG, Batenburg JJ. Aggregation of Cryptococcus neoformans by surfactant protein D is inhibited by its capsular component glucuronoxylomannan. Infect Immun 2004; 72:145-53. [PMID: 14688091 PMCID: PMC343972 DOI: 10.1128/iai.72.1.145-153.2004] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cryptococcus neoformans is an opportunistic pathogen invading the immunocompromised host. Infection starts with the inhalation of acapsular or sparsely encapsulated cells, after which capsule synthesis is initiated. The capsule is the main virulence factor of this yeast-like fungus. Pulmonary surfactant protein D (SP-D) is an important component of the local innate defense system. In the present study, interactions of SP-D with intact C. neoformans cells and their isolated capsular components were investigated. Although encapsulated cryptococci were bound, SP-D showed the highest affinity for acapsular C. neoformans. Only acapsular cryptococci were aggregated by SP-D. Furthermore, the cryptococcal capsular components glucuronoxylomannan (GXM) and mannoprotein 1 (MP1) were bound with relatively high affinity, in contrast to GalXM and MP2. Binding as well as aggregation of acapsular C. neoformans by SP-D could be inhibited by GXM in concentrations that are likely to be present in the lung after infection, suggesting that not only the capsule hampers SP-D function within the innate defense system of the lung but also the secreted capsular component GXM.
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Affiliation(s)
- J K van de Wetering
- Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine, Graduate School of Animal Health, Utrecht University, Utrecht, The Netherlands
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41
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Abstract
Pulmonary surfactant is a mixture of lipids, mostly phospholipids, and proteins that allows for breathing with minimal effort. The current chapter discusses the metabolism of the phospholipids of this material. Surfactant phospholipids are synthesized in the type II epithelial cells of the lung. The lipids and surfactant proteins are assembled in intracellular storage organelles, called lamellar bodies, and are subsequently secreted into the alveolar space. Within this extracellular space surfactant undergoes several transformations. First the lamellar bodies unravel to form a highly organized lattice-like lipid:protein structure tubular myelin. Second, the organized structures, in particular tubular myelin, adsorb to form a lipid at the air-liquid interface of the alveoli. It is, in fact, this surface tension reducing film that is responsible for the physiological role of surfactant, to prevent lung collapse and allow ease of inflation. Third, the surface film is converted to a small vesicular form. Finally, these small vesicles are taken-up by the type II cells for recycling and degradation and by alveolar macrophages for degradation.
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Affiliation(s)
- Ruud Veldhuizen
- Departments of Medicine and Physiology and Pharmacology, Lawson Health Research Institute, London, ON, N6A 4V2, Canada
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42
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Griese M, Wiesener A, Lottspeich F, von Bredow C. Limited proteolysis of surfactant protein D causes a loss of its calcium-dependent lectin functions. BIOCHIMICA ET BIOPHYSICA ACTA 2003; 1638:157-63. [PMID: 12853121 DOI: 10.1016/s0925-4439(03)00063-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Surfactant protein D (SP-D) is a multimeric collagenous lectin that mediates the clearance of pathogens and modulates immune cell functions via its C-terminal carbohydrate recognition domain (CRD). We hypothesized that extracellular proteolysis of SP-D may result in a loss of its functional properties. Multimeric SP-D was partially digested by human leukocyte elastase (HLE) dose- and time-dependently. Physiologic concentrations of calcium slowed, but did not protect from degradation. In solution, both native and degraded SP-D had an apparent molecular weight of 650 to >1000 kDa. Under reducing conditions, the degraded SP-D monomers run at 10 kDa less than native SP-D. Amino acid sequencing located all major cleavage sites into the CRD. Functional studies showed that degraded SP-D had lost its calcium-dependent lectin properties, i.e. neither bound to mannose nor agglutinated bacteria. These studies demonstrate that elastase results in the limited proteolysis of SP-D with loss of its CRD-dependent activities and suggest that proteases at concentrations observed in various lung diseases may impair the antimicrobial and immunomodulatory roles of SP-D.
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Affiliation(s)
- M Griese
- The Lung Research Group, Children's Hospital of Ludwig Maximilians University, Lindwurmstrasse 4, D-80337 Munich, Germany.
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43
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Nadesalingam J, Bernal AL, Dodds AW, Willis AC, Mahoney DJ, Day AJ, Reid KBM, Palaniyar N. Identification and characterization of a novel interaction between pulmonary surfactant protein D and decorin. J Biol Chem 2003; 278:25678-87. [PMID: 12730206 DOI: 10.1074/jbc.m210186200] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Surfactant-associated protein D (SP-D) is a collectin that is present in lung surfactant and mucosal surfaces. Although SP-D regulates diverse functions, only a few proteins are known to bind to this collectin. Here we describe the co-purification of decorin, a novel SP-D-binding protein, from amniotic fluid. The human decorin that co-purified with SP-D is a 130-150-kDa proteoglycan, which has a 46-kDa protein core and approximately 90-kDa dermatan sulfate chain. Both native and recombinant decorin can bind to SP-D that is already bound to maltose-agarose matrix, and these SP-D-decorin complexes are dissociated at high salt (0.5-1.0 m NaCl) conditions, releasing the decorin. We further show that SP-D and decorin interact with each other (kd = 4 nm) by two mechanisms. First, the direct binding and competition experiments show that the carbohydrate recognition domain (CRD) of SP-D binds in a calcium dependent-manner to the sulfated N-acetyl galactosamine moiety of the glycosaminoglycan chain. Second, complement component C1q, a complement protein that is known to interact with decorin core protein via its collagen-like region, partially blocks the interaction between decorin and native SP-D. This protein, however, does not block the interaction between decorin and SP-D(n/CRD), a recombinant fragment that lacks the N-terminal and collagen-like regions. Furthermore, the core protein, obtained by chondroitin ABC lyase treatment of decorin, binds SP-D, but not SP-D(n/CRD). These findings suggest that decorin core protein binds the collagen-like region of the SP-D. Concentrations of decorin and SP-D are negatively correlated to each other, in amniotic fluid, implying a functional relevance for SP-D-decorin interaction, in vivo. Collectively, our results show that carbohydrate recognition domains of SP-D interact with the dermatan sulfate moiety of decorin via lectin activity and that the core protein of decorin binds the collagen-like region of SP-D in vitro, and these interactions may be operative in vivo.
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Affiliation(s)
- Jeya Nadesalingam
- Medical Research Council Immunochemistry Unit, Department of Biochemistry, Oxford University, South Parks Road, Oxford OX1 3QU, United Kingdom
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44
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Borron PJ, Mostaghel EA, Doyle C, Walsh ES, McHeyzer-Williams MG, Wright JR. Pulmonary surfactant proteins A and D directly suppress CD3+/CD4+ cell function: evidence for two shared mechanisms. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2002; 169:5844-50. [PMID: 12421966 DOI: 10.4049/jimmunol.169.10.5844] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Pulmonary surfactant is a lipoprotein complex that lowers surface tension at the air-liquid interface of the lung and participates in pulmonary host defense. Surfactant proteins (SP), SP-A and SP-D, modulate a variety of immune cell functions, including the production of cytokines and free radicals. Previous studies showed that SP-A and SP-D inhibit lymphocyte proliferation in the presence of accessory cells. The goal of this study was to determine whether SP-A and SP-D directly suppress Th cell function. Both proteins inhibited CD3(+)/CD4(+) lymphocyte proliferation induced by PMA and ionomycin in an IL-2-independent manner. Both proteins decreased the number of cells entering the S and mitotic phases of the cell cycle. Neither SP-A nor SP-D altered cell viability, apoptosis, or secretion of IL-2, IL-4, or IFN-gamma when Th cells were treated with PMA and ionomycin. However, both proteins attenuated ionomycin-induced cytosolic free calcium ([Ca(2+) ](i)), but not thapsigargin-induced changes in [Ca(2+)](i). In summary, inhibition of T cell proliferation by SP-A and SP-D occurs via two mechanisms, an IL-2-dependent mechanism observed with accessory cell-dependent T cell mitogens and specific Ag, as well as an IL-2-independent mechanism of suppression that potentially involves attenuation of [Ca(2+)](i).
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Affiliation(s)
- Paul J Borron
- Departments of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
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45
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Ehebauer MT, Mans BJ, Gaspar ARM, Neitz AWH. Identification of extrinsic blood coagulation pathway inhibitors from the tick Ornithodoros savignyi (Acari: Argasidae). Exp Parasitol 2002; 101:138-48. [PMID: 12427468 DOI: 10.1016/s0014-4894(02)00102-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The salt BaSO(4) selectively adsorbs two proteins from crude Ornithodoros savignyi salivary gland extract. They co-purify during reversed-phase HPLC, but can be separated by hydrophobic-interaction chromatography. Their molecular masses are 9333 and 9173Da. The 9.3kDa protein was designated BSAP1 and the 9.1kDa protein BSAP2. Their amino acid compositions show significant differences, in particular the presence of seven and eight cysteine residues in BSAP1 and BSAP2, respectively. The proteins do not contain gamma-carboxyglutamic acid, hydroxyproline, or hydroxylysine. The proteins do not inhibit the intrinsic coagulation cascade, but inhibit the extrinsic pathway. The observed inhibition is not due to inhibition of factor VII. Both proteins bind to membranes. BSAP1 binds neutral and negatively charged membranes more strongly than BSAP2. Its affinity for negative membranes is, however, much lower than for neutral membranes. In contrast, BSAP2 binds both membranes equally strongly. The binding of the proteins to the membranes was significantly lowered upon pre-incubation with Ca(2+).
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Affiliation(s)
- M T Ehebauer
- Department of Biochemistry, University of Pretoria, Pretoria, South Africa
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46
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Ohtani K, Suzuki Y, Eda S, Kawai T, Kase T, Keshi H, Sakai Y, Fukuoh A, Sakamoto T, Itabe H, Suzutani T, Ogasawara M, Yoshida I, Wakamiya N. The membrane-type collectin CL-P1 is a scavenger receptor on vascular endothelial cells. J Biol Chem 2001; 276:44222-8. [PMID: 11564734 DOI: 10.1074/jbc.m103942200] [Citation(s) in RCA: 151] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Collectins are a family of C-type lectins that have collagen-like sequences and carbohydrate recognition domains (CRD). They are involved in host defense through their ability to bind to carbohydrate antigens of microorganisms. The scavenger receptors type A and MARCO are classical type scavenger receptors that have internal collagen-like domains. Here we describe a new scavenger receptor that is a membrane-type collectin from placenta (collectin placenta 1 (CL-P1)), which has a typical collectin collagen-like domain and a CRD. The cDNA has an insert of about 2.2 kilobases coding for a protein containing 742 amino acid residues. The deduced amino acid sequence shows that CL-P1 is a type II membrane protein, has a coiled-coil region, a collagen-like domain, and a CRD. It resembles type A scavenger receptors because the scavenger receptor cysteine-rich domain is replaced by a CRD. Northern analyses, reverse transcription-polymerase chain reaction, and immunohistochemistry show that CL-P1 is expressed in vascular endothelial cells but not in macrophages. By immunoblotting and flow cytometry CL-P1 appears to be a membrane glycoprotein of about 140 kDa in human umbilical vein or arterial endothelial cells, placental membrane extracts, and CL-P1 transfected Chinese hamster ovary cells. We found that CL-P1 can bind and phagocytose not only bacteria (Escherichia coli and Staphylococcus aureus) but also yeast (Saccharomyces cerevisiae). Furthermore, it reacts with oxidized low density lipoprotein (OxLDL) but not with acetylated LDL (AcLDL). These binding activities are inhibited by polyanionic ligands (polyinosinic acid, polyguanylic acid, dextran sulfate) and OxLDL but not by polycationic ligands (polyadenylic acid or polycytidylic acid), LDL, or AcLDL. These results indicate that CL-P1 might play important roles in host defenses that are different from those of soluble collectins in innate immunity.
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MESH Headings
- Amino Acid Sequence
- Animals
- Base Sequence
- CHO Cells
- Cell Membrane/metabolism
- Cloning, Molecular
- Collectins
- Cricetinae
- DNA Primers
- Endothelium, Vascular/cytology
- Endothelium, Vascular/metabolism
- Humans
- Lectins/chemistry
- Lectins/genetics
- Lectins/metabolism
- Membrane Proteins
- Molecular Sequence Data
- Receptors, Cell Surface/chemistry
- Receptors, Cell Surface/genetics
- Receptors, Cell Surface/metabolism
- Receptors, Immunologic/metabolism
- Receptors, Lipoprotein
- Receptors, Scavenger
- Scavenger Receptors, Class A
- Scavenger Receptors, Class B
- Sequence Homology, Amino Acid
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Affiliation(s)
- K Ohtani
- Department of Microbiology, Asahikawa Medical College, Midorigaoka-Higashi, Asahikawa 078-8510, Japan
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47
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Günther A, Ruppert C, Schmidt R, Markart P, Grimminger F, Walmrath D, Seeger W. Surfactant alteration and replacement in acute respiratory distress syndrome. Respir Res 2001; 2:353-64. [PMID: 11737935 PMCID: PMC64803 DOI: 10.1186/rr86] [Citation(s) in RCA: 163] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2001] [Accepted: 07/12/2001] [Indexed: 01/11/2023] Open
Abstract
The acute respiratory distress syndrome (ARDS) is a frequent, life-threatening disease in which a marked increase in alveolar surface tension has been repeatedly observed. It is caused by factors including a lack of surface-active compounds, changes in the phospholipid, fatty acid, neutral lipid, and surfactant apoprotein composition, imbalance of the extracellular surfactant subtype distribution, inhibition of surfactant function by plasma protein leakage, incorporation of surfactant phospholipids and apoproteins into polymerizing fibrin, and damage/inhibition of surfactant compounds by inflammatory mediators. There is now good evidence that these surfactant abnormalities promote alveolar instability and collapse and, consequently, loss of compliance and the profound gas exchange abnormalities seen in ARDS. An acute improvement of gas exchange properties together with a far-reaching restoration of surfactant properties was encountered in recently performed pilot studies. Here we summarize what is known about the kind and severity of surfactant changes occurring in ARDS, the contribution of these changes to lung failure, and the role of surfactant administration for therapy of ARDS.
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Affiliation(s)
- A Günther
- Department of Internal Medicine, Justus-Liebig-University Giessen, Germany.
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48
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Savani RC, Godinez RI, Godinez MH, Wentz E, Zaman A, Cui Z, Pooler PM, Guttentag SH, Beers MF, Gonzales LW, Ballard PL. Respiratory distress after intratracheal bleomycin: selective deficiency of surfactant proteins B and C. Am J Physiol Lung Cell Mol Physiol 2001; 281:L685-96. [PMID: 11504697 DOI: 10.1152/ajplung.2001.281.3.l685] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Intratracheal bleomycin in rats is associated with respiratory distress of uncertain etiology. We investigated the expression of surfactant components in this model of lung injury. Maximum respiratory distress, determined by respiratory rate, occurred at 7 days, and surfactant dysfunction was confirmed by increased surface tension of the large-aggregate fraction of bronchoalveolar lavage (BAL). In injured animals, phospholipid content and composition were similar to those of controls, mature surfactant protein (SP) B was decreased 90%, and SP-A and SP-D contents were increased. In lung tissue, SP-B and SP-C mRNAs were decreased by 2 days and maximally at 4--7 days and recovered between 14 and 21 days after injury. Immunostaining of SP-B and proSP-C was decreased in type II epithelial cells but strong in macrophages. By electron microscopy, injured lungs had type II cells lacking lamellar bodies and macrophages with phagocytosed lamellar bodies. Surface activity of BAL phospholipids of injured animals was restored by addition of exogenous SP-B. We conclude that respiratory distress after bleomycin in rats results from surfactant dysfunction in part secondary to selective downregulation of SP-B and SP-C.
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Affiliation(s)
- R C Savani
- Division of Neonatology, Department of Pediatrics, The Children's Hospital of Philadelphia and University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104-4399, USA.
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49
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Haagsman HP, Diemel RV. Surfactant-associated proteins: functions and structural variation. Comp Biochem Physiol A Mol Integr Physiol 2001; 129:91-108. [PMID: 11369536 DOI: 10.1016/s1095-6433(01)00308-7] [Citation(s) in RCA: 136] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Pulmonary surfactant is a barrier material of the lungs and has a dual role: firstly, as a true surfactant, lowering the surface tension; and secondly, participating in innate immune defence of the lung and possibly other mucosal surfaces. Surfactant is composed of approximately 90% lipids and 10% proteins. There are four surfactant-specific proteins, designated surfactant protein A (SP-A), SP-B, SP-C and SP-D. Although the sequences and post-translational modifications of SP-B and SP-C are quite conserved between mammalian species, variations exist. The hydrophilic surfactant proteins SP-A and SP-D are members of a family of collagenous carbohydrate binding proteins, known as collectins, consisting of oligomers of trimeric subunits. In view of the different roles of surfactant proteins, studies determining the structure-function relationships of surfactant proteins across the animal kingdom will be very interesting. Such studies may reveal structural elements of the proteins required for surface film dynamics as well as those required for innate immune defence. Since SP-A and SP-D are also present in extrapulmonary tissues, the hydrophobic surfactant proteins SP-B and SP-C may be the most appropriate indicators for the evolutionary origin of surfactant. SP-B is essential for air-breathing in mammals and is therefore largely conserved. Yet, because of its unique structure and its localization in the lung but not in extrapulmonary tissues, SP-C may be the most important indicator for the evolutionary origin of surfactant.
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Affiliation(s)
- H P Haagsman
- Department of Biochemistry, Cell Biology and Histology and Graduate School of Animal Health, Utrecht University, P.O. Box 80175, 3508 TD, Utrecht, The Netherlands.
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50
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McCormack FX. Functional mapping of surfactant protein A. PEDIATRIC PATHOLOGY & MOLECULAR MEDICINE 2001; 20:293-318. [PMID: 11486735 DOI: 10.1080/15513810109168823] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Surfactant protein A (SP-A) is a highly ordered, oligomeric glycoprotein that is secreted into the airspaces of the lung by alveolar type II cells and Clara cells of the pulmonary epithelium. Although research has shown that SP-A is both a calcium-dependent phospholipid-binding protein that affects surfactant structure and function and a lectin that opsonizes diverse microbial species, our understanding of the physiologically relevant roles of SP-A in the lung remains incomplete. My review focuses on the putative biological functions of SP-A that are supported by experiments in mammals and on the structural basis of SP-A function.
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Affiliation(s)
- F X McCormack
- Division of Pulmonary and Critical Case Medicine, Univ. of Cincinnati College of Medicine, 231 Albert Sabin Way, Cincinnati, OH 45267-0564, USA.
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