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Valand N, Gazioglu O, Yesilkaya H, Shivkumar M, Horley N, Arroo R, Wallis R, Kishore U, Venkatraman Girija U. Interactions of Candida tropicalis pH-related antigen 1 with complement proteins C3, C3b, factor-H, C4BP and complement evasion. Immunobiology 2023; 228:152303. [PMID: 36495597 DOI: 10.1016/j.imbio.2022.152303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 11/14/2022] [Accepted: 11/18/2022] [Indexed: 11/25/2022]
Abstract
Candida, as a part of the human microbiota, can cause opportunistic infections that are either localised or systemic candidiasis. Emerging resistance to the standard antifungal drugs is associated with increased mortality rate due to invasive Candida infections, particularly in immunocompromised patients. While there are several species of Candida, an increasing number of Candida tropicalis isolates have been recently reported from patients with invasive candidiasis or inflammatory bowel diseases. In order to establish infections, C. tropicalis has to adopt several strategies to escape the host immune attack. Understanding the immune evasion strategies is of great importance as these can be exploited as novel therapeutic targets. C. albicans pH-related antigen 1 (CaPra1), a surface bound and secretory protein, has been found to interact strongly with the immune system and help in complement evasion. However, the role of C. tropicalis Pra1 (CtPra1) and its interaction with the complement is not studied yet. Thus, we characterised how pH-related antigen 1 of C. tropicalis (CtPra1) interacts with some of the key complement proteins of the innate immune system. CtPra1 was recombinantly produced using a Kluyveromyces lactis yeast expression system. Recombinant CtPra1, was found to bind human C3 and C3b, central molecules of the complement pathways that are important components of the innate immune system. It was also found to bind human complement regulatory proteins factor-H and C4b-binding protein (C4BP). CtPra1-factor-H and CtPra1-C4BP interactions were found to be ionic in nature as the binding intensity affected by high sodium chloride concentrations. CtPra1 inhibited functional complement activation with different effects on classical (∼20 %), lectin (∼25 %) and alternative (∼30 %) pathways. qPCR experiments using C. tropicalis clinical isolates (oral, blood and peritoneal fluid) revealed relatively higher levels of expression of CtPra1 gene when compared to the reference strain. Native CtPra1 was found to be expressed both as membrane-bound and secretory forms in the clinical isolates. Thus, C. tropicalis appears to be a master of immune evasion by using Pra1 protein. Further investigation using in-vivo models will help ascertain if these proteins can be novel therapeutic targets.
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Affiliation(s)
- Nisha Valand
- Faculty of Health & Life Sciences, De Montfort University, UK
| | - Ozcan Gazioglu
- Department of Respiratory Sciences, University of Leicester, UK
| | - Hasan Yesilkaya
- Department of Respiratory Sciences, University of Leicester, UK
| | | | - Neill Horley
- Faculty of Health & Life Sciences, De Montfort University, UK
| | - Randolph Arroo
- Faculty of Health & Life Sciences, De Montfort University, UK
| | - Russell Wallis
- Department of Respiratory Sciences, University of Leicester, UK
| | - Uday Kishore
- Department of Veterinary Medicine, U.A.E. University, Al Ain, United Arab Emirates
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2
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Valand N, Brunt E, Gazioglu O, Yesilkaya H, Mitchell D, Horley N, Arroo R, Kishore U, Wallis R, Girija UV. Inactivation of the Complement Lectin Pathway by Candida tropicalis Secreted Aspartyl Protease-1. Immunobiology 2022; 227:152263. [DOI: 10.1016/j.imbio.2022.152263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 08/16/2022] [Accepted: 08/21/2022] [Indexed: 11/16/2022]
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3
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Abdullah IT, Ulijasz AT, Girija UV, Tam S, Andrew P, Hiller NL, Wallis R, Yesilkaya H. Structure‐function analysis for development of peptide inhibitors for a Gram positive quorum sensing system. Mol Microbiol 2022; 117:1464-1478. [PMID: 35575437 PMCID: PMC9233744 DOI: 10.1111/mmi.14921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 05/05/2022] [Accepted: 05/11/2022] [Indexed: 11/27/2022]
Abstract
The Streptococcus pneumoniae Rgg144/SHP144 regulator‐peptide quorum sensing (QS) system is critical for nutrient utilization, oxidative stress response, and virulence. Here, we characterized this system by assessing the importance of each residue within the active short hydrophobic peptide (SHP) by alanine‐scanning mutagenesis and testing the resulting peptides for receptor binding and activation of the receptor. Interestingly, several of the mutations had little effect on binding to Rgg144 but reduced transcriptional activation appreciably. In particular, a proline substitution (P21A) reduced transcriptional activation by 29‐fold but bound with a 3‐fold higher affinity than the wild‐type SHP. Consistent with the function of Rgg144, the mutant peptide led to decreased utilization of mannose and increased susceptibility to superoxide generator paraquat. Pangenome comparison showed full conservation of P21 across SHP144 allelic variants. Crystallization of Rgg144 in the absence of peptide revealed a comparable structure to the DNA bound and free forms of its homologs suggesting similar mechanisms of activation. Together, these analyses identify key interactions in a critical pneumococcal QS system. Further manipulation of the SHP has the potential to facilitate the development of inhibitors that are functional across strains. The approach described here is likely to be effective across QS systems in multiple species.
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Affiliation(s)
- Iman Tajer Abdullah
- Department of Respiratory Sciences University of Leicester Leicester United Kingdom
- Department of Biology, College of Science University of Kirkuk Iraq
| | - Andrew T. Ulijasz
- Department of Microbiology and Immunology Loyola University Chicago Maywood IL USA
| | | | - Sien Tam
- Department of Biological Sciences Carnegie Mellon University Pittsburgh, PA 15213
| | - Peter Andrew
- Department of Respiratory Sciences University of Leicester Leicester United Kingdom
| | - N. Luisa Hiller
- Department of Biological Sciences Carnegie Mellon University Pittsburgh, PA 15213
| | - Russell Wallis
- Department of Respiratory Sciences University of Leicester Leicester United Kingdom
| | - Hasan Yesilkaya
- Department of Respiratory Sciences University of Leicester Leicester United Kingdom
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4
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Ghauri K, Pijning T, Munawar N, Ali H, Ghauri MA, Anwar MA, Wallis R. Crystal structure of an inulosucrase from
Halalkalicoccus
jeotgali
B3T, a halophilic archaeal strain. FEBS J 2021. [DOI: https://doi.org/10.1111/febs.15843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Komal Ghauri
- Industrial Biotechnology Division National Institute for Biotechnology and Genetic Engineering Constituent College of Pakistan Institute of Engineering and Applied Sciences Faisalabad Pakistan
| | - Tjaard Pijning
- Department of Biomolecular X‐ray Crystallography Groningen Biomolecular Sciences and Biotechnology Institute University of Groningen The Netherlands
| | - Nayla Munawar
- Department of Chemistry College of Sciences United Arab Emirates University Al‐Ain UAE
| | - Hazrat Ali
- Industrial Biotechnology Division National Institute for Biotechnology and Genetic Engineering Constituent College of Pakistan Institute of Engineering and Applied Sciences Faisalabad Pakistan
| | - Muhammad A. Ghauri
- Industrial Biotechnology Division National Institute for Biotechnology and Genetic Engineering Constituent College of Pakistan Institute of Engineering and Applied Sciences Faisalabad Pakistan
| | - Munir A. Anwar
- Industrial Biotechnology Division National Institute for Biotechnology and Genetic Engineering Constituent College of Pakistan Institute of Engineering and Applied Sciences Faisalabad Pakistan
| | - Russell Wallis
- Department of Respiratory Sciences Maurice Shock Medical Sciences Building University of Leicester UK
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Ghauri K, Pijning T, Munawar N, Ali H, Ghauri MA, Anwar MA, Wallis R. Crystal structure of an inulosucrase from Halalkalicoccus jeotgali B3T, a halophilic archaeal strain. FEBS J 2021; 288:5723-5736. [PMID: 33783128 DOI: 10.1111/febs.15843] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 02/19/2021] [Accepted: 03/25/2021] [Indexed: 12/28/2022]
Abstract
Several archaea harbor genes that code for fructosyltransferase (FTF) enzymes. These enzymes have not been characterized yet at structure-function level, but are of extreme interest in view of their potential role in the synthesis of novel compounds for food, nutrition, and pharmaceutical applications. In this study, 3D structure of an inulin-type fructan producing enzyme, inulosucrase (InuHj), from the archaeon Halalkalicoccus jeotgali was resolved in its apo form and with bound substrate (sucrose) molecule and first transglycosylation product (1-kestose). This is the first crystal structure of an FTF from halophilic archaea. Its overall five-bladed β-propeller fold is conserved with previously reported FTFs, but also shows some unique features. The InuHj structure is closer to those of Gram-negative bacteria, with exceptions such as residue E266, which is conserved in FTFs of Gram-positive bacteria and has possible role in fructan polymer synthesis in these bacteria as compared to fructooligosaccharide (FOS) production by FTFs of Gram-negative bacteria. Highly negative electrostatic surface potential of InuHj, due to a large amount of acidic residues, likely contributes to its halophilicity. The complex of InuHj with 1-kestose indicates that the residues D287 in the 4B-4C loop, Y330 in 4D-5A, and D361 in the unique α2 helix may interact with longer FOSs and facilitate the binding of longer FOS chains during synthesis. The outcome of this work will provide targets for future structure-function studies of FTF enzymes, particularly those from archaea.
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Affiliation(s)
- Komal Ghauri
- Industrial Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, Constituent College of Pakistan Institute of Engineering and Applied Sciences, Faisalabad, Pakistan
| | - Tjaard Pijning
- Department of Biomolecular X-ray Crystallography, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, The Netherlands
| | - Nayla Munawar
- Department of Chemistry, College of Sciences, United Arab Emirates University, Al-Ain, UAE
| | - Hazrat Ali
- Industrial Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, Constituent College of Pakistan Institute of Engineering and Applied Sciences, Faisalabad, Pakistan
| | - Muhammad A Ghauri
- Industrial Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, Constituent College of Pakistan Institute of Engineering and Applied Sciences, Faisalabad, Pakistan
| | - Munir A Anwar
- Industrial Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, Constituent College of Pakistan Institute of Engineering and Applied Sciences, Faisalabad, Pakistan
| | - Russell Wallis
- Department of Respiratory Sciences, Maurice Shock Medical Sciences Building, University of Leicester, UK
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6
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Mercurio D, Oggioni M, Fumagalli S, Lynch NJ, Roscher S, Minuta D, Perego C, Ippati S, Wallis R, Schwaeble WJ, De Simoni MG. Targeted deletions of complement lectin pathway genes improve outcome in traumatic brain injury, with MASP-2 playing a major role. Acta Neuropathol Commun 2020; 8:174. [PMID: 33115535 PMCID: PMC7592565 DOI: 10.1186/s40478-020-01041-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 09/24/2020] [Indexed: 12/13/2022] Open
Abstract
The lectin pathway (LP) of complement activation is believed to contribute to brain inflammation. The study aims to identify the key components of the LP contributing to TBI outcome as possible novel pharmacological targets. We compared the long-term neurological deficits and neuropathology of wild-type mice (WT) to that of mice carrying gene deletions of key LP components after experimental TBI. WT or MASP-2 (Masp2-/-), ficolin-A (Fcna-/-), CL-11 (Colec11-/-), MASP-1/3 (Masp1-/-), MBL-C (Mbl2-/-), MBL-A (Mbl1-/-) or MBL-/- (Mbl1-/-/Mbl2-/-) deficient male C57BL/6J mice were used. Mice underwent sham surgery or TBI by controlled cortical impact. The sensorimotor response was evaluated by neuroscore and beam walk tests weekly for 4 weeks. To obtain a comparative analysis of the functional outcome each transgenic line was rated according to a health score calculated on sensorimotor performance. For selected genotypes, brains were harvested 6 weeks after injury for histopathological analysis. MASP-2-/-, MBL-/- and FCN-A-/- mice had better outcome scores compared to WT. Of these, MASP-2-/- mice had the best recovery after TBI, showing reduced sensorimotor deficits (by 33% at 3 weeks and by 36% at 4 weeks). They also showed higher neuronal density in the lesioned cortex with a 31.5% increase compared to WT. Measurement of LP functional activity in plasma from MASP-2-/- mice revealed the absence of LP functional activity using a C4b deposition assay. The LP critically contributes to the post-traumatic inflammatory pathology following TBI with the highest degree of protection achieved through the absence of the LP key enzyme MASP-2, underlining a therapeutic utility of MASP-2 targeting in TBI.
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Affiliation(s)
- D Mercurio
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, via Mario Negri 2, 20156, Milan, Italy
| | - M Oggioni
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, via Mario Negri 2, 20156, Milan, Italy
| | - S Fumagalli
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, via Mario Negri 2, 20156, Milan, Italy
| | - N J Lynch
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, via Mario Negri 2, 20156, Milan, Italy
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, CB3 0ES, Cambridge, UK
| | - S Roscher
- Department of Respiratory Sciences, University of Leicester, University Road, LE1 9HN, Leicester, UK
| | - D Minuta
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, via Mario Negri 2, 20156, Milan, Italy
- San Raffaele Scientific Institute, San Raffaele Hospital, 20132, Milan, Italy
| | - C Perego
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, via Mario Negri 2, 20156, Milan, Italy
| | - S Ippati
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, via Mario Negri 2, 20156, Milan, Italy
- National Research Council (CNR), Institute of Neuroscience, 20129, Milan, Italy
| | - R Wallis
- Department of Respiratory Sciences, University of Leicester, University Road, LE1 9HN, Leicester, UK
| | - W J Schwaeble
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, CB3 0ES, Cambridge, UK
| | - M-G De Simoni
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, via Mario Negri 2, 20156, Milan, Italy.
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7
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Polycarpou A, Howard M, Farrar CA, Greenlaw R, Fanelli G, Wallis R, Klavinskis LS, Sacks S. Rationale for targeting complement in COVID-19. EMBO Mol Med 2020; 12:e12642. [PMID: 32559343 PMCID: PMC7323084 DOI: 10.15252/emmm.202012642] [Citation(s) in RCA: 84] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 05/28/2020] [Accepted: 06/16/2020] [Indexed: 12/13/2022] Open
Abstract
A novel coronavirus, SARS-CoV-2, has recently emerged in China and spread internationally, posing a health emergency to the global community. COVID-19 caused by SARS-CoV-2 is associated with an acute respiratory illness that varies from mild to the life-threatening acute respiratory distress syndrome (ARDS). The complement system is part of the innate immune arsenal against pathogens, in which many viruses can evade or employ to mediate cell entry. The immunopathology and acute lung injury orchestrated through the influx of pro-inflammatory macrophages and neutrophils can be directly activated by complement components to prime an overzealous cytokine storm. The manifestations of severe COVID-19 such as the ARDS, sepsis and multiorgan failure have an established relationship with activation of the complement cascade. We have collected evidence from all the current studies we are aware of on SARS-CoV-2 immunopathogenesis and the preceding literature on SARS-CoV-1 and MERS-CoV infection linking severe COVID-19 disease directly with dysfunction of the complement pathways. This information lends support for a therapeutic anti-inflammatory strategy against complement, where a number of clinically ready potential therapeutic agents are available.
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MESH Headings
- Adult
- Alveolar Epithelial Cells/immunology
- Alveolar Epithelial Cells/metabolism
- Alveolar Epithelial Cells/virology
- Angiotensin-Converting Enzyme 2
- Animals
- Betacoronavirus/physiology
- COVID-19
- Child
- Complement Activation/drug effects
- Complement C3b/antagonists & inhibitors
- Complement C3b/physiology
- Complement Inactivating Agents/pharmacology
- Complement Inactivating Agents/therapeutic use
- Coronavirus Infections/drug therapy
- Coronavirus Infections/immunology
- Cytokine Release Syndrome/drug therapy
- Cytokine Release Syndrome/etiology
- Cytokine Release Syndrome/immunology
- Glycosylation
- Humans
- Immunity, Innate
- Ligands
- Mice
- Models, Animal
- Models, Molecular
- Pandemics
- Pattern Recognition, Automated
- Peptidyl-Dipeptidase A/metabolism
- Pneumonia, Viral/drug therapy
- Pneumonia, Viral/immunology
- Protein Conformation
- Protein Processing, Post-Translational
- Receptors, Virus/metabolism
- Respiratory Distress Syndrome/etiology
- Respiratory Distress Syndrome/immunology
- SARS-CoV-2
- Spike Glycoprotein, Coronavirus/chemistry
- Spike Glycoprotein, Coronavirus/metabolism
- COVID-19 Drug Treatment
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Affiliation(s)
- Anastasia Polycarpou
- MRC Centre of TransplantationPeter Gorer Department of ImmunobiologySchool of Immunology and Microbial SciencesGuy's HospitalKing's College LondonLondonUK
| | - Mark Howard
- MRC Centre of TransplantationPeter Gorer Department of ImmunobiologySchool of Immunology and Microbial SciencesGuy's HospitalKing's College LondonLondonUK
| | - Conrad A Farrar
- MRC Centre of TransplantationPeter Gorer Department of ImmunobiologySchool of Immunology and Microbial SciencesGuy's HospitalKing's College LondonLondonUK
| | - Roseanna Greenlaw
- MRC Centre of TransplantationPeter Gorer Department of ImmunobiologySchool of Immunology and Microbial SciencesGuy's HospitalKing's College LondonLondonUK
| | - Giorgia Fanelli
- MRC Centre of TransplantationPeter Gorer Department of ImmunobiologySchool of Immunology and Microbial SciencesGuy's HospitalKing's College LondonLondonUK
| | - Russell Wallis
- Department of Respiratory Science and InfectionLeicester Institute of Chemical and Structural BiologyUniversity of LeicesterLeicesterUK
| | - Linda S Klavinskis
- Department of Infectious DiseasesSchool of Immunology and Microbial SciencesGuy's HospitalKing's College LondonLondonUK
| | - Steven Sacks
- MRC Centre of TransplantationPeter Gorer Department of ImmunobiologySchool of Immunology and Microbial SciencesGuy's HospitalKing's College LondonLondonUK
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8
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Howard MC, Nauser CL, Farrar CA, Wallis R, Sacks SH. l-Fucose prevention of renal ischaemia/reperfusion injury in Mice. FASEB J 2019; 34:822-834. [PMID: 31914693 PMCID: PMC6972607 DOI: 10.1096/fj.201901582r] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 10/04/2019] [Accepted: 10/08/2019] [Indexed: 01/16/2023]
Abstract
In a recent study, we identified a fucosylated damage‐associated ligand exposed by ischemia on renal tubule epithelial cells, which after recognition by collectin‐11 (CL‐11 or collectin kidney 1 (CL‐K1)), initiates complement activation and acute kidney injury. We exploited the ability to increase the local tissue concentration of free l‐fucose following systemic administration, in order to block ligand binding by local CL‐11 and prevent complement activation. We achieved a thirty‐five‐fold increase in the intrarenal concentration of l‐fucose following an IP bolus given before the ischemia induction procedure ‐ a concentration found to significantly block in vitro binding of CL‐11 on hypoxia‐stressed renal tubule cells. At this l‐fucose dose, complement activation and acute post‐ischemic kidney injury are prevented, with additional protection achieved by a second bolus after the induction procedure. CL‐11−/− mice gained no additional protection from l‐fucose administration, indicating that the mechanism of l‐fucose therapy was largely CL‐11‐dependent. The hypothesis is that a high dose of l‐fucose delivered to the kidney obstructs the carbohydrate recognition site on CL‐11 thereby reducing complement‐mediated damage following ischemic insult. Further work will examine the utility in preventing post‐ischemic injury during renal transplantation, where acute kidney injury is known to correlate with poor graft survival.
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Affiliation(s)
- Mark C Howard
- MRC Centre for Transplantation, Peter Gorer Department of Immunobiology, School of Immunology & Microbial Sciences, King's College London, London, UK
| | - Christopher L Nauser
- MRC Centre for Transplantation, Peter Gorer Department of Immunobiology, School of Immunology & Microbial Sciences, King's College London, London, UK
| | - Conrad A Farrar
- MRC Centre for Transplantation, Peter Gorer Department of Immunobiology, School of Immunology & Microbial Sciences, King's College London, London, UK
| | - Russell Wallis
- Department of Respiratory Science and Infection, University of Leicester, London, UK
| | - Steven H Sacks
- MRC Centre for Transplantation, Peter Gorer Department of Immunobiology, School of Immunology & Microbial Sciences, King's College London, London, UK
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Jenkins CH, Wallis R, Allcock N, Barnes KB, Richards MI, Auty JM, Galyov EE, Harding SV, Mukamolova GV. The lytic transglycosylase, LtgG, controls cell morphology and virulence in Burkholderia pseudomallei. Sci Rep 2019; 9:11060. [PMID: 31363151 PMCID: PMC6667503 DOI: 10.1038/s41598-019-47483-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 07/15/2019] [Indexed: 02/07/2023] Open
Abstract
Burkholderia pseudomallei is the causative agent of the tropical disease melioidosis. Its genome encodes an arsenal of virulence factors that allow it, when required, to switch from a soil dwelling bacterium to a deadly intracellular pathogen. With a high intrinsic resistance to antibiotics and the ability to overcome challenges from the host immune system, there is an increasing requirement for new antibiotics and a greater understanding into the molecular mechanisms of B. pseudomallei virulence and dormancy. The peptidoglycan remodeling enzymes, lytic transglycosylases (Ltgs) are potential targets for such new antibiotics. Ltgs cleave the glycosidic bonds within bacterial peptidoglycan allowing for the insertion of peptidoglycan precursors during cell growth and division, and cell membrane spanning structures such as flagella and secretion systems. Using bioinformatic analysis we have identified 8 putative Ltgs in B. pseudomallei K96243. We aimed to investigate one of these Ltgs, LtgG (BPSL3046) through the generation of deletion mutants and biochemical analysis. We have shown that LtgG is a key contributor to cellular morphology, division, motility and virulence in BALB/c mice. We have determined the crystal structure of LtgG and have identified various amino acids likely to be important in peptidoglycan binding and catalytic activity. Recombinant protein assays and complementation studies using LtgG containing a site directed mutation in aspartate 343, confirmed the essentiality of this amino acid in the function of LtgG.
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Affiliation(s)
- Christopher H Jenkins
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, UK. .,Defence Science and Technology Laboratory, Chemical, Biological and Radiological Division, Porton Down, Salisbury, Wiltshire, UK.
| | - Russell Wallis
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, UK.,The Leicester Institute of Structural and Chemical Biology, Henry Wellcome Building, University of Leicester, Leicester, UK
| | - Natalie Allcock
- Electron Microscopy Facility, Core Biotechnology Services, University of Leicester, Leicester, UK
| | - Kay B Barnes
- Defence Science and Technology Laboratory, Chemical, Biological and Radiological Division, Porton Down, Salisbury, Wiltshire, UK
| | - Mark I Richards
- Defence Science and Technology Laboratory, Chemical, Biological and Radiological Division, Porton Down, Salisbury, Wiltshire, UK
| | - Joss M Auty
- Department of Respiratory Sciences, University of Leicester, Leicester, UK
| | - Edouard E Galyov
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, UK.,Department of Genetics and Genome Biology, University of Leicester, Leicester, UK
| | - Sarah V Harding
- Defence Science and Technology Laboratory, Chemical, Biological and Radiological Division, Porton Down, Salisbury, Wiltshire, UK.,Department of Respiratory Sciences, University of Leicester, Leicester, UK
| | - Galina V Mukamolova
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, UK. .,Department of Respiratory Sciences, University of Leicester, Leicester, UK.
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10
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Turapov O, Forti F, Kadhim B, Ghisotti D, Sassine J, Straatman-Iwanowska A, Bottrill AR, Moynihan PJ, Wallis R, Barthe P, Cohen-Gonsaud M, Ajuh P, Vollmer W, Mukamolova GV. Two Faces of CwlM, an Essential PknB Substrate, in Mycobacterium tuberculosis. Cell Rep 2018; 25:57-67.e5. [PMID: 30282038 PMCID: PMC6180346 DOI: 10.1016/j.celrep.2018.09.004] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 06/11/2018] [Accepted: 08/31/2018] [Indexed: 11/26/2022] Open
Abstract
Tuberculosis claims >1 million lives annually, and its causative agent Mycobacterium tuberculosis is a highly successful pathogen. Protein kinase B (PknB) is reported to be critical for mycobacterial growth. Here, we demonstrate that PknB-depleted M. tuberculosis can replicate normally and can synthesize peptidoglycan in an osmoprotective medium. Comparative phosphoproteomics of PknB-producing and PknB-depleted mycobacteria identify CwlM, an essential regulator of peptidoglycan synthesis, as a major PknB substrate. Our complementation studies of a cwlM mutant of M. tuberculosis support CwlM phosphorylation as a likely molecular basis for PknB being essential for mycobacterial growth. We demonstrate that growing mycobacteria produce two forms of CwlM: a non-phosphorylated membrane-associated form and a PknB-phosphorylated cytoplasmic form. Furthermore, we show that the partner proteins for the phosphorylated and non-phosphorylated forms of CwlM are FhaA, a fork head-associated domain protein, and MurJ, a proposed lipid II flippase, respectively. From our results, we propose a model in which CwlM potentially regulates both the biosynthesis of peptidoglycan precursors and their transport across the cytoplasmic membrane.
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Affiliation(s)
- Obolbek Turapov
- Leicester Tuberculosis Research Group, Department of Infection, Immunity and Inflammation, University of Leicester, Leicester LE1 9HN, UK
| | - Francesca Forti
- Department of Biosciences, University of Milan, Milan 20133, Italy
| | - Baleegh Kadhim
- Leicester Tuberculosis Research Group, Department of Infection, Immunity and Inflammation, University of Leicester, Leicester LE1 9HN, UK; Biology Department, College of Science, University of Al-Qadisiyah, Al-Diwaniyah 58002, Iraq
| | - Daniela Ghisotti
- Department of Biosciences, University of Milan, Milan 20133, Italy
| | - Jad Sassine
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE2 4AX, UK
| | - Anna Straatman-Iwanowska
- Electron Microscopy Facility, Core Biotechnology Services, University of Leicester, Leicester LE1 7RH, UK
| | - Andrew R Bottrill
- Protein Nucleic Acid Laboratory, University of Leicester, Leicester LE1 7RH, UK
| | - Patrick J Moynihan
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Russell Wallis
- Leicester Tuberculosis Research Group, Department of Infection, Immunity and Inflammation, University of Leicester, Leicester LE1 9HN, UK; The Leicester Institute of Structural and Chemical Biology, Henry Wellcome Building, University of Leicester, Lancaster Road, Leicester LE1 7HB, UK
| | - Philippe Barthe
- Centre de Biochimie Structurale, CNRS, INSERM, University of Montpellier, Montpellier 34090, France
| | - Martin Cohen-Gonsaud
- Centre de Biochimie Structurale, CNRS, INSERM, University of Montpellier, Montpellier 34090, France
| | - Paul Ajuh
- Gemini Biosciences, Liverpool Science Park, Liverpool L3 5TF, UK
| | - Waldemar Vollmer
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE2 4AX, UK
| | - Galina V Mukamolova
- Leicester Tuberculosis Research Group, Department of Infection, Immunity and Inflammation, University of Leicester, Leicester LE1 9HN, UK.
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11
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Mitchell DA, Zhang Q, Voorhaar L, Haddleton DM, Herath S, Gleinich AS, Randeva HS, Crispin M, Lehnert H, Wallis R, Patterson S, Becer CR. Manipulation of cytokine secretion in human dendritic cells using glycopolymers with picomolar affinity for DC-SIGN. Chem Sci 2017; 8:6974-6980. [PMID: 29147524 PMCID: PMC5642150 DOI: 10.1039/c7sc01515a] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 08/11/2017] [Indexed: 12/25/2022] Open
Abstract
The human C-type lectin DC-SIGN (CD209) is a significant receptor on the surface of dendritic cells (DCs) - crucial components of host defense that bridge the innate and adaptive immune systems. A range of linear glycopolymers, constructed via controlled radical polymerization techniques have been shown to interact with DC-SIGN with affinities in the physiologically active range. However, these first generation glycopolymers possess limited structural definition and their effects on DCs were not known. Here we report the development of star-shaped mannose glycopolymers with the aim of targeting the clustered domain arrangement of DC-SIGN and these were shown to bind with picomolar affinity. Increased secretion of IL-10 with simultaneous decrease in secreted IL-12p70 occurred in activated DCs incubated with star-shaped glycopolymers - a cytokine secretion pattern characteristic of wound-healing tissue environments. Incorporating stellar architecture into glycopolymer design could be key to developing selective and very high-affinity therapeutic materials with distinct immunomodulatory and tissue repair potential.
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Affiliation(s)
- Daniel A Mitchell
- Clinical Sciences Research Laboratories , University of Warwick , Coventry CV2 2DX , United Kingdom . .,University Hospital Coventry , Warwickshire NHS Trust , Coventry CV2 2DX , United Kingdom
| | - Qiang Zhang
- Department of Chemistry , University of Warwick , Coventry CV4 7AL , United Kingdom
| | - Lenny Voorhaar
- Department of Chemistry , University of Warwick , Coventry CV4 7AL , United Kingdom
| | - David M Haddleton
- Department of Chemistry , University of Warwick , Coventry CV4 7AL , United Kingdom
| | - Shan Herath
- Chelsea & Westminster Hospital , Imperial College School of Medicine , London SW10 9NH , United Kingdom
| | - Anne S Gleinich
- Clinical Sciences Research Laboratories , University of Warwick , Coventry CV2 2DX , United Kingdom .
| | - Harpal S Randeva
- Clinical Sciences Research Laboratories , University of Warwick , Coventry CV2 2DX , United Kingdom . .,University Hospital Coventry , Warwickshire NHS Trust , Coventry CV2 2DX , United Kingdom
| | - Max Crispin
- Glycobiology Institute , University of Oxford , Oxford OX1 3QU , United Kingdom
| | | | - Russell Wallis
- Department of Biochemistry , University of Leicester , Leicester LE1 9HN , United Kingdom
| | - Steven Patterson
- Chelsea & Westminster Hospital , Imperial College School of Medicine , London SW10 9NH , United Kingdom
| | - C Remzi Becer
- School of Engineering and Materials Science , Queen Mary University , London E1 4NS , United Kingdom .
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12
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Nixon A, Glozier N, Fields K, Wallis R, Biddle D, Chan C, Hickie I, De Konink J, Robillard R. 1098 IMPROVEMENTS IN SUBJECTIVE SLEEP AND DEPRESSION ALONG THE COURSE OF ADJUNCTIVE PHOTOTHERAPY. Sleep 2017. [DOI: 10.1093/sleepj/zsx050.1097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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13
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Yaseen S, Demopulos G, Dudler T, Yabuki M, Wood CL, Cummings WJ, Tjoelker LW, Fujita T, Sacks S, Garred P, Andrew P, Sim RB, Lachmann PJ, Wallis R, Lynch N, Schwaeble WJ. Lectin pathway effector enzyme mannan-binding lectin-associated serine protease-2 can activate native complement C3 in absence of C4 and/or C2. FASEB J 2017; 31:2210-2219. [PMID: 28188176 DOI: 10.1096/fj.201601306r] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 01/23/2017] [Indexed: 02/06/2023]
Abstract
All 3 activation pathways of complement-the classic pathway (CP), the alternative pathway, and the lectin pathway (LP)- converge into a common central event: the cleavage and activation of the abundant third complement component, C3, via formation of C3-activating enzymes (C3 convertases). The fourth complement component, C4, and the second component, C2, are indispensable constituents of the C3 convertase complex, C4bC2a, which is formed by both the CP and the LP. Whereas in the absence of C4, CP can no longer activate C3, LP retains a residual but physiologically critical capacity to convert native C3 into its activation fragments, C3a and C3b. This residual C4 and/or C2 bypass route is dependent on LP-specific mannan-binding lectin-associated serine protease-2. By using various serum sources with defined complement deficiencies, we demonstrate that, under physiologic conditions LP-specific C4 and/or C2 bypass activation of C3 is mediated by direct cleavage of native C3 by mannan-binding lectin-associated serine protease-2 bound to LP-activation complexes captured on ligand-coated surfaces.-Yaseen, S., Demopulos, G., Dudler, T., Yabuki, M., Wood, C. L., Cummings, W. J., Tjoelker, L. W., Fujita, T., Sacks, S., Garred, P., Andrew, P., Sim, R. B., Lachmann, P. J., Wallis, R., Lynch, N., Schwaeble, W. J. Lectin pathway effector enzyme mannan-binding lectin-associated serine protease-2 can activate native complement C3 in absence of C4 and/or C2.
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Affiliation(s)
- Sadam Yaseen
- Department of Infection, Immunity, and Inflammation, University of Leicester, Leicester, United Kingdom.,Omeros Corporation, Seattle, Washington, USA.,Department of Biology, University of Mosul, Mosul, Iraq
| | | | | | | | | | | | | | - Teizo Fujita
- Fukushima Prefectural General Hygiene Institute, Fukushima Medical University, Fukushima City, Japan
| | - Steven Sacks
- Medical Research Council (MRC) Centre for Transplantation, King's College London, Guy's Campus, London, United Kingdom
| | - Peter Garred
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Peter Andrew
- Department of Infection, Immunity, and Inflammation, University of Leicester, Leicester, United Kingdom
| | - Robert B Sim
- Department of Infection, Immunity, and Inflammation, University of Leicester, Leicester, United Kingdom
| | - Peter J Lachmann
- Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Russell Wallis
- Department of Infection, Immunity, and Inflammation, University of Leicester, Leicester, United Kingdom
| | - Nicholas Lynch
- Department of Infection, Immunity, and Inflammation, University of Leicester, Leicester, United Kingdom
| | - Wilhelm J Schwaeble
- Department of Infection, Immunity, and Inflammation, University of Leicester, Leicester, United Kingdom;
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14
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Nan R, Furze CM, Wright DW, Gor J, Wallis R, Perkins SJ. Flexibility in Mannan-Binding Lectin-Associated Serine Proteases-1 and -2 Provides Insight on Lectin Pathway Activation. Structure 2017; 25:364-375. [PMID: 28111019 PMCID: PMC5300068 DOI: 10.1016/j.str.2016.12.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 12/08/2016] [Accepted: 12/21/2016] [Indexed: 01/19/2023]
Abstract
The lectin pathway of complement is activated by complexes comprising a recognition component (mannose-binding lectin, serum ficolins, collectin-LK or collectin-K1) and a serine protease (MASP-1 or MASP-2). MASP-1 activates MASP-2, and MASP-2 cleaves C4 and C4b-bound C2. To clarify activation, new crystal structures of Ca2+-bound MASP dimers were determined, together with their solution structures from X-ray scattering, analytical ultracentrifugation, and atomistic modeling. Solution structures of the CUB1-EGF-CUB2 dimer of each MASP indicate that the two CUB2 domains were tilted by as much as 90° compared with the crystal structures, indicating considerable flexibility at the EGF-CUB2 junction. Solution structures of the full-length MASP dimers in their zymogen and activated forms revealed similar structures that were much more bent than anticipated from crystal structures. We conclude that MASP-1 and MASP-2 are flexible at multiple sites and that this flexibility may permit both intra- and inter-complex activation.
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Affiliation(s)
- Ruodan Nan
- Department of Structural and Molecular Biology, Division of Biosciences, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Christopher M Furze
- Departments of Infection, Immunity and Inflammation and Molecular Cell Biology, University of Leicester, University Road, Leicester, LE1 9HN, UK
| | - David W Wright
- Department of Structural and Molecular Biology, Division of Biosciences, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Jayesh Gor
- Department of Structural and Molecular Biology, Division of Biosciences, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Russell Wallis
- Departments of Infection, Immunity and Inflammation and Molecular Cell Biology, University of Leicester, University Road, Leicester, LE1 9HN, UK
| | - Stephen J Perkins
- Department of Structural and Molecular Biology, Division of Biosciences, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK.
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15
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Wallis R, Innocenti RD, Jessop DS, Mitrofanov O, Bledt CM, Melzer JE, Harrington JA, Beere HE, Ritchie DA. Investigation of hollow cylindrical metal terahertz waveguides suitable for cryogenic environments. Opt Express 2016; 24:30002-30014. [PMID: 28059385 DOI: 10.1364/oe.24.030002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The field of terahertz (THz) waveguides continues to grow rapidly, with many being tailored to suit the specific demands of a particular final application. Here, we explore waveguides capable of enabling efficient and accurate power delivery within cryogenic environments (< 4 K). The performance of extruded hollow cylindrical metal waveguides made of un-annealed and annealed copper, as well as stainless steel, have been investigated for bore diameters between 1.75 - 4.6 mm, and at frequencies of 2.0, 2.85 and 3.4 THz, provided by a suitable selection of THz quantum cascade lasers. The annealed copper resulted in the lowest transmission losses, < 3 dB/m for a 4.6 mm diameter waveguide, along with 90° bending losses as low as ~2 dB for a bend radius of 15.9 mm. The observed trends in losses were subsequently analyzed and related to measured inner surface roughness parameters. These results provide a foundation for the development of a wide array of demanding low-temperature THz applications, and enabling the study of fundamental physics.
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16
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Pilecki B, Holm AT, Schlosser A, Moeller JB, Wohl AP, Zuk AV, Heumüller SE, Wallis R, Moestrup SK, Sengle G, Holmskov U, Sorensen GL. Characterization of Microfibrillar-associated Protein 4 (MFAP4) as a Tropoelastin- and Fibrillin-binding Protein Involved in Elastic Fiber Formation. J Biol Chem 2015; 291:1103-14. [PMID: 26601954 DOI: 10.1074/jbc.m115.681775] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Indexed: 11/06/2022] Open
Abstract
MFAP4 (microfibrillar-associated protein 4) is an extracellular glycoprotein found in elastic fibers without a clearly defined role in elastic fiber assembly. In the present study, we characterized molecular interactions between MFAP4 and elastic fiber components. We established that MFAP4 primarily assembles into trimeric and hexameric structures of homodimers. Binding analysis revealed that MFAP4 specifically binds tropoelastin and fibrillin-1 and -2, as well as the elastin cross-linking amino acid desmosine, and that it co-localizes with fibrillin-1-positive fibers in vivo. Site-directed mutagenesis disclosed residues Phe(241) and Ser(203) in MFAP4 as being crucial for type I collagen, elastin, and tropoelastin binding. Furthermore, we found that MFAP4 actively promotes tropoelastin self-assembly. In conclusion, our data identify MFAP4 as a new ligand of microfibrils and tropoelastin involved in proper elastic fiber organization.
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Affiliation(s)
- Bartosz Pilecki
- From the Department of Cancer and Inflammation Research, Institute of Molecular Medicine, Faculty of Health Sciences, University of Southern Denmark, 5000 Odense C, Denmark
| | - Anne T Holm
- From the Department of Cancer and Inflammation Research, Institute of Molecular Medicine, Faculty of Health Sciences, University of Southern Denmark, 5000 Odense C, Denmark
| | - Anders Schlosser
- From the Department of Cancer and Inflammation Research, Institute of Molecular Medicine, Faculty of Health Sciences, University of Southern Denmark, 5000 Odense C, Denmark
| | - Jesper B Moeller
- From the Department of Cancer and Inflammation Research, Institute of Molecular Medicine, Faculty of Health Sciences, University of Southern Denmark, 5000 Odense C, Denmark
| | | | | | - Stefanie E Heumüller
- the Center for Biochemistry, Faculty of Medicine and the Center for Molecular Medicine Cologne, University of Cologne, 50931 Cologne, Germany
| | - Russell Wallis
- the Department of Infection, Immunity and Inflammation, and Department of Molecular and Cell Biology, University of Leicester, Leicester LE1 9HN, United Kingdom, and
| | - Soren K Moestrup
- From the Department of Cancer and Inflammation Research, Institute of Molecular Medicine, Faculty of Health Sciences, University of Southern Denmark, 5000 Odense C, Denmark, the Department of Clinical Biochemistry and Pharmacology, Odense University Hospital, 5000 Odense C, Denmark
| | - Gerhard Sengle
- the Center for Biochemistry, Faculty of Medicine and the Center for Molecular Medicine Cologne, University of Cologne, 50931 Cologne, Germany
| | - Uffe Holmskov
- From the Department of Cancer and Inflammation Research, Institute of Molecular Medicine, Faculty of Health Sciences, University of Southern Denmark, 5000 Odense C, Denmark
| | - Grith L Sorensen
- From the Department of Cancer and Inflammation Research, Institute of Molecular Medicine, Faculty of Health Sciences, University of Southern Denmark, 5000 Odense C, Denmark,
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17
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Wallis R, Degl'Iinnocenti R, Jessop DS, Ren Y, Klimont A, Shah YD, Mitrofanov O, Bledt CM, Melzer JE, Harrington JA, Beere HE, Ritchie DA. Efficient coupling of double-metal terahertz quantum cascade lasers to flexible dielectric-lined hollow metallic waveguides. Opt Express 2015; 23:26276-26287. [PMID: 26480141 DOI: 10.1364/oe.23.026276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The growth in terahertz frequency applications utilising the quantum cascade laser is hampered by a lack of targeted power delivery solutions over large distances (>100 mm). Here we demonstrate the efficient coupling of double-metal quantum cascade lasers into flexible polystyrene lined hollow metallic waveguides via the use of a hollow copper waveguide integrated into the laser mounting block. Our approach exhibits low divergence, Gaussian-like emission, which is robust to misalignment error, at distances > 550 mm, with a coupling efficiency from the hollow copper waveguide into the flexible waveguide > 90%. We also demonstrate the ability to nitrogen purge the flexible waveguide, increasing the power transmission by up to 20% at 2.85 THz, which paves the way for future fibre based terahertz sensing and spectroscopy applications.
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18
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Marshall JE, Faraj BHA, Gingras AR, Lonnen R, Sheikh MA, El-Mezgueldi M, Moody PCE, Andrew PW, Wallis R. The Crystal Structure of Pneumolysin at 2.0 Å Resolution Reveals the Molecular Packing of the Pre-pore Complex. Sci Rep 2015; 5:13293. [PMID: 26333773 PMCID: PMC4558608 DOI: 10.1038/srep13293] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 07/16/2015] [Indexed: 11/09/2022] Open
Abstract
Pneumolysin is a cholesterol-dependent cytolysin (CDC) and virulence factor of Streptococcus pneumoniae. It kills cells by forming pores assembled from oligomeric rings in cholesterol-containing membranes. Cryo-EM has revealed the structures of the membrane-surface bound pre-pore and inserted-pore oligomers, however the molecular contacts that mediate these oligomers are unknown because high-resolution information is not available. Here we have determined the crystal structure of full-length pneumolysin at 1.98 Å resolution. In the structure, crystal contacts demonstrate the likely interactions that enable polymerisation on the cell membrane and the molecular packing of the pre-pore complex. The hemolytic activity is abrogated in mutants that disrupt these intermolecular contacts, highlighting their importance during pore formation. An additional crystal structure of the membrane-binding domain alone suggests that changes in the conformation of a tryptophan rich-loop at the base of the toxin promote monomer-monomer interactions upon membrane binding by creating new contacts. Notably, residues at the interface are conserved in other members of the CDC family, suggesting a common mechanism for pore and pre-pore assembly.
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Affiliation(s)
- Jamie E Marshall
- Department of Infection, Immunity and Inflammation, University of Leicester, PO Box 138, Leicester, LE1 9HN UK
| | - Bayan H A Faraj
- Department of Infection, Immunity and Inflammation, University of Leicester, PO Box 138, Leicester, LE1 9HN UK
| | - Alexandre R Gingras
- Department of Biochemistry, University of Leicester, PO Box 138, Leicester, LE1 9HN UK
| | - Rana Lonnen
- Department of Infection, Immunity and Inflammation, University of Leicester, PO Box 138, Leicester, LE1 9HN UK
| | - Md Arif Sheikh
- Department of Infection, Immunity and Inflammation, University of Leicester, PO Box 138, Leicester, LE1 9HN UK
| | - Mohammed El-Mezgueldi
- Department of Biochemistry, University of Leicester, PO Box 138, Leicester, LE1 9HN UK
| | - Peter C E Moody
- Department of Biochemistry, University of Leicester, PO Box 138, Leicester, LE1 9HN UK
| | - Peter W Andrew
- Department of Infection, Immunity and Inflammation, University of Leicester, PO Box 138, Leicester, LE1 9HN UK
| | - Russell Wallis
- Department of Infection, Immunity and Inflammation, University of Leicester, PO Box 138, Leicester, LE1 9HN UK.,Department of Biochemistry, University of Leicester, PO Box 138, Leicester, LE1 9HN UK
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19
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Bidula S, Sexton DW, Yates M, Abdolrasouli A, Shah A, Wallis R, Reed A, Armstrong-James D, Schelenz S. H-ficolin binds Aspergillus fumigatus leading to activation of the lectin complement pathway and modulation of lung epithelial immune responses. Immunology 2015; 146:281-91. [PMID: 26133042 DOI: 10.1111/imm.12501] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Revised: 06/25/2015] [Accepted: 06/25/2015] [Indexed: 01/07/2023] Open
Abstract
Aspergillus fumigatus is an opportunistic fungal pathogen that typically infects the lungs of immunocompromised patients leading to a high mortality. H-Ficolin, an innate immune opsonin, is produced by type II alveolar epithelial cells and could participate in lung defences against infections. Here, we used the human type II alveolar epithelial cell line, A549, to determine the involvement of H-ficolin in fungal defence. Additionally, we investigated the presence of H-ficolin in bronchoalveolar lavage fluid from transplant patients during pneumonia. H-Ficolin exhibited demonstrable binding to A. fumigatus conidia via l-fucose, d-mannose and N-acetylglucosamine residues in a calcium- and pH-dependent manner. Moreover, recognition led to lectin complement pathway activation and enhanced fungal association with A549 cells. Following recognition, H-ficolin opsonization manifested an increase in interleukin-8 production from A549 cells, which involved activation of the intracellular signalling pathways mitogen-activated protein kinase MAPK kinase 1/2, p38 MAPK and c-Jun N-terminal kinase. Finally, H-ficolin concentrations were significantly higher in bronchoalveolar lavage fluid of patients with lung infections compared with control subjects (n = 16; P = 0·00726). Receiver operating characteristics curve analysis further highlighted the potential of H-ficolin as a diagnostic marker for lung infection (area under the curve = 0·77; P < 0·0001). Hence, H-ficolin participates in A. fumigatus defence through the activation of the lectin complement pathway, enhanced fungus-host interactions and modulated immune responses.
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Affiliation(s)
- Stefan Bidula
- Biomedical Research Centre, Norwich Medical School, University of East Anglia, Norwich, UK.,Aberdeen Fungal Group, School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK
| | - Darren W Sexton
- Biomedical Research Centre, Norwich Medical School, University of East Anglia, Norwich, UK.,School of Pharmacy and Biomolecular Science, Liverpool John Moores University, Liverpool, UK
| | - Matthew Yates
- Biomedical Research Centre, Norwich Medical School, University of East Anglia, Norwich, UK
| | - Alireza Abdolrasouli
- Section of Infectious Diseases and Immunity, Imperial College London, London, UK
| | - Anand Shah
- Section of Infectious Diseases and Immunity, Imperial College London, London, UK
| | - Russell Wallis
- Departments of Infection, Immunity and Inflammation and Biochemistry, University of Leicester, Leicester, UK
| | - Anna Reed
- Department of Lung Transplantation, Harefield Hospital, Middlesex, UK
| | | | - Silke Schelenz
- Biomedical Research Centre, Norwich Medical School, University of East Anglia, Norwich, UK.,Department of Microbiology, Royal Brompton Hospital, London, UK
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20
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Semblat JP, Ghumra A, Czajkowsky DM, Wallis R, Mitchell DA, Raza A, Rowe JA. Identification of the minimal binding region of a Plasmodium falciparum IgM binding PfEMP1 domain. Mol Biochem Parasitol 2015; 201:76-82. [PMID: 26094597 PMCID: PMC4539346 DOI: 10.1016/j.molbiopara.2015.06.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Revised: 05/22/2015] [Accepted: 06/08/2015] [Indexed: 11/29/2022]
Abstract
Many pathogens bind the Fc region of host immunoglobulin to evade immunity. We examined a Plasmodium falciparum IgM binding PfEMP1 domain TM284var1 DBL4ζ. We identified the minimal IgM binding region comprising subdomain 2 and flanking regions. Specific charged amino acids were mutated but did not markedly affect IgM binding. Existing models of PfEMP1-IgM interaction need to be revised.
Binding of host immunoglobulin is a common immune evasion mechanism demonstrated by microbial pathogens. Previous work showed that the malaria parasite Plasmodium falciparum binds the Fc-region of human IgM molecules, resulting in a coating of IgM on the surface of infected erythrocytes. IgM binding is a property of P. falciparum strains showing virulence-related phenotypes such as erythrocyte rosetting. The parasite ligands for IgM binding are members of the diverse P. falciparum Erythrocyte Membrane Protein One (PfEMP1) family. However, little is known about the amino acid sequence requirements for IgM binding. Here we studied an IgM binding domain from a rosette-mediating PfEMP1 variant, DBL4ζ of TM284var1, and found that the minimal IgM binding region mapped to the central region of the DBL domain, comprising all of subdomain 2 and adjoining parts of subdomains 1 and 3. Site-directed mutagenesis of charged amino acids within subdomain 2, predicted by molecular modelling to form the IgM binding site, showed no marked effect on IgM binding properties. Overall, this study identifies the minimal IgM binding region of a PfEMP1 domain, and indicates that the existing homology model of PfEMP1-IgM interaction is incorrect. Further work is needed to identify the specific interaction site for IgM within the minimal binding region of PfEMP1.
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Affiliation(s)
- Jean-Philippe Semblat
- Institute of Immunology and Infection Research, Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, United Kingdom
| | - Ashfaq Ghumra
- Institute of Immunology and Infection Research, Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, United Kingdom
| | - Daniel M Czajkowsky
- Bio-ID Center, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Russell Wallis
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom
| | - Daniel A Mitchell
- Clinical Sciences Research Laboratories, Warwick Medical School, Coventry CV2 2DX, United Kingdom
| | - Ahmed Raza
- Institute of Immunology and Infection Research, Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, United Kingdom
| | - J Alexandra Rowe
- Institute of Immunology and Infection Research, Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, United Kingdom.
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21
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Venkatraman Girija U, Furze CM, Gingras AR, Yoshizaki T, Ohtani K, Marshall JE, Wallis AK, Schwaeble WJ, El-Mezgueldi M, Mitchell DA, Moody PCE, Wakamiya N, Wallis R. Molecular basis of sugar recognition by collectin-K1 and the effects of mutations associated with 3MC syndrome. BMC Biol 2015; 13:27. [PMID: 25912189 PMCID: PMC4431178 DOI: 10.1186/s12915-015-0136-2] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 04/01/2015] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Collectin-K1 (CL-K1, or CL-11) is a multifunctional Ca(2+)-dependent lectin with roles in innate immunity, apoptosis and embryogenesis. It binds to carbohydrates on pathogens to activate the lectin pathway of complement and together with its associated serine protease MASP-3 serves as a guidance cue for neural crest development. High serum levels are associated with disseminated intravascular coagulation, where spontaneous clotting can lead to multiple organ failure. Autosomal mutations in the CL-K1 or MASP-3 genes cause a developmental disorder called 3MC (Carnevale, Mingarelli, Malpuech and Michels) syndrome, characterised by facial, genital, renal and limb abnormalities. One of these mutations (Gly(204)Ser in the CL-K1 gene) is associated with undetectable levels of protein in the serum of affected individuals. RESULTS In this study, we show that CL-K1 primarily targets a subset of high-mannose oligosaccharides present on both self- and non-self structures, and provide the structural basis for its ligand specificity. We also demonstrate that three disease-associated mutations prevent secretion of CL-K1 from mammalian cells, accounting for the protein deficiency observed in patients. Interestingly, none of the mutations prevent folding or oligomerization of recombinant fragments containing the mutations in vitro. Instead, they prevent Ca(2+) binding by the carbohydrate-recognition domains of CL-K1. We propose that failure to bind Ca(2+) during biosynthesis leads to structural defects that prevent secretion of CL-K1, thus providing a molecular explanation of the genetic disorder. CONCLUSIONS We have established the sugar specificity of CL-K1 and demonstrated that it targets high-mannose oligosaccharides on self- and non-self structures via an extended binding site which recognises the terminal two mannose residues of the carbohydrate ligand. We have also shown that mutations associated with a rare developmental disorder called 3MC syndrome prevent the secretion of CL-K1, probably as a result of structural defects caused by disruption of Ca(2+) binding during biosynthesis.
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Affiliation(s)
- Umakhanth Venkatraman Girija
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, LE1 9HN, UK. .,Department of Biochemistry, University of Leicester, Leicester, LE1 9HN, UK.
| | - Christopher M Furze
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, LE1 9HN, UK.
| | - Alexandre R Gingras
- Department of Biochemistry, University of Leicester, Leicester, LE1 9HN, UK. .,Department of Medicine, University of California San Diego, La Jolla, CA, 92093-0726, USA.
| | - Takayuki Yoshizaki
- Department of Microbiology and Immunochemistry, Asahikawa Medical University, 2-1-1-1 Midorigaoka-Higashi, Asahikawa, 078-8510, Japan.
| | - Katsuki Ohtani
- Department of Microbiology and Immunochemistry, Asahikawa Medical University, 2-1-1-1 Midorigaoka-Higashi, Asahikawa, 078-8510, Japan.
| | - Jamie E Marshall
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, LE1 9HN, UK.
| | - A Katrine Wallis
- Department of Applied Science and Health, Coventry University, Coventry, CV1 5FB, UK.
| | - Wilhelm J Schwaeble
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, LE1 9HN, UK.
| | | | - Daniel A Mitchell
- Clinical Sciences Research Laboratories, Warwick Medical School, University Hospital Coventry & Warwickshire Coventry, Coventry, CV2 2DX, UK.
| | - Peter C E Moody
- Department of Biochemistry, University of Leicester, Leicester, LE1 9HN, UK.
| | - Nobutaka Wakamiya
- Department of Microbiology and Immunochemistry, Asahikawa Medical University, 2-1-1-1 Midorigaoka-Higashi, Asahikawa, 078-8510, Japan.
| | - Russell Wallis
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, LE1 9HN, UK. .,Department of Biochemistry, University of Leicester, Leicester, LE1 9HN, UK.
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22
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Zumla A, Rao M, Parida SK, Keshavjee S, Cassell G, Wallis R, Axelsson-Robertsson R, Doherty M, Andersson J, Maeurer M. Inflammation and tuberculosis: host-directed therapies. J Intern Med 2015; 277:373-87. [PMID: 24717092 DOI: 10.1111/joim.12256] [Citation(s) in RCA: 91] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Tuberculosis (TB) is an airborne infectious disease that kills almost two million individuals every year. Multidrug-resistant (MDR) TB is caused by strains of Mycobacterium tuberculosis (M. tb) resistant to isoniazid and rifampin, the backbone of first-line antitubercular treatment. MDR TB affects an estimated 500,000 new patients annually. Genetic analysis of drug-resistant MDR-TB showed that airborne transmission of undetected and untreated strains played a major role in disease outbreaks. The need for new TB vaccines and faster diagnostics, as well as the development of new drugs, has recently been highlighted. The major problem in terms of current TB research and clinical demands is the increasing number of cases of extensively drug-resistant and 'treatment-refractory' TB. An emerging scenario of adjunct host-directed therapies is intended to target pulmonary TB where inflammatory processes can be deleterious and lead to immune exhaustion. 'Target-organ-saving' strategies may be warranted to prevent damage to infected tissues and achieve focused, clinically relevant and long-lasting anti-M. tb cellular immune responses. Candidates for such interventions may be biological agents or already approved drugs that can be 're-purposed' to interfere with biologically relevant cellular checkpoints. Here, we review current concepts of inflammation in TB disease and discuss candidate pathways for host-directed therapies to achieve better clinical outcomes.
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Affiliation(s)
- A Zumla
- University College London, University College London Hospitals NHS Foundation Trust, London, UK
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23
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Risteli M, Ruotsalainen H, Bergmann U, Venkatraman Girija U, Wallis R, Myllylä R. Lysyl hydroxylase 3 modifies lysine residues to facilitate oligomerization of mannan-binding lectin. PLoS One 2014; 9:e113498. [PMID: 25419660 PMCID: PMC4242627 DOI: 10.1371/journal.pone.0113498] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 10/24/2014] [Indexed: 01/17/2023] Open
Abstract
Lysyl hydroxylase 3 (LH3) is a multifunctional protein with lysyl hydroxylase, galactosyltransferase and glucosyltransferase activities. The LH3 has been shown to modify the lysine residues both in collagens and also in some collagenous proteins. In this study we show for the first time that LH3 is essential for catalyzing formation of the glucosylgalactosylhydroxylysines of mannan-binding lectin (MBL), the first component of the lectin pathway of complement activation. Furthermore, loss of the terminal glucose units on the derivatized lysine residues in mouse embryonic fibroblasts lacking the LH3 protein leads to defective disulphide bonding and oligomerization of rat MBL-A, with a decrease in the proportion of the larger functional MBL oligomers. The oligomerization could be completely restored with the full length LH3 or the amino-terminal fragment of LH3 that possesses the glycosyltransferase activities. Our results confirm that LH3 is the only enzyme capable of glucosylating the galactosylhydroxylysine residues in proteins with a collagenous domain. In mice lacking the lysyl hydroxylase activity of LH3, but with untouched galactosyltransferase and glucosyltransferase activities, reduced circulating MBL-A levels were observed. Oligomerization was normal, however and residual lysyl hydroxylation was compensated in part by other lysyl hydroxylase isoenzymes. Our data suggest that LH3 is commonly involved in biosynthesis of collagenous proteins and the glucosylation of galactosylhydroxylysines residues by LH3 is crucial for the formation of the functional high-molecular weight MBL oligomers.
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Affiliation(s)
- Maija Risteli
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
- Department of Diagnostics and Oral Medicine, Institute of Dentistry, University of Oulu, Oulu, Finland
- Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland
- * E-mail:
| | - Heli Ruotsalainen
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
- Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Ulrich Bergmann
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
- Biocenter Oulu, Mass Spectrometry Core Facility, University of Oulu, Oulu, Finland
| | | | - Russell Wallis
- Department of Infection, Immunity, and Inflammation, University of Leicester, Leicester, United Kingdom
- Department of Biochemistry, University of Leicester, Leicester, United Kingdom
| | - Raili Myllylä
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
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24
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Zhang Q, Su L, Collins J, Chen G, Wallis R, Mitchell DA, Haddleton DM, Becer CR. Dendritic Cell Lectin-Targeting Sentinel-like Unimolecular Glycoconjugates To Release an Anti-HIV Drug. J Am Chem Soc 2014; 136:4325-32. [DOI: 10.1021/ja4131565] [Citation(s) in RCA: 127] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Qiang Zhang
- Department
of Chemistry, University of Warwick, CV4 7AL Coventry, United Kingdom
| | - Lu Su
- State
Key Laboratory of Molecular Engineering of Polymers, Ministry of Education
and Department of Macromolecular Science, Fudan University, 220
Handan Road, Shanghai 200433, China
| | - Jennifer Collins
- Department
of Chemistry, University of Warwick, CV4 7AL Coventry, United Kingdom
| | - Guosong Chen
- State
Key Laboratory of Molecular Engineering of Polymers, Ministry of Education
and Department of Macromolecular Science, Fudan University, 220
Handan Road, Shanghai 200433, China
| | - Russell Wallis
- Department
of Biochemistry, University of Leicester, LE1 9HN Leicester, United Kingdom
| | - Daniel A. Mitchell
- Clinical
Sciences Research Laboratories, Warwick Medical School, University of Warwick, CV2 2DX Coventry, United Kingdom
| | - David M. Haddleton
- Department
of Chemistry, University of Warwick, CV4 7AL Coventry, United Kingdom
| | - C. Remzi Becer
- Department
of Chemistry, University of Warwick, CV4 7AL Coventry, United Kingdom
- School
of Engineering and Materials Science, Queen Mary University of London, Mile End Road, E1 4NS London, United Kingdom
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25
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Saeed A, Baloch K, Brown RJP, Wallis R, Chen L, Dexter L, McClure CP, Shakesheff K, Thomson BJ. Mannan binding lectin-associated serine protease 1 is induced by hepatitis C virus infection and activates human hepatic stellate cells. Clin Exp Immunol 2013; 174:265-73. [PMID: 23841802 DOI: 10.1111/cei.12174] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/28/2013] [Indexed: 01/26/2023] Open
Abstract
Mannan binding lectin (MBL)-associated serine protease type 1 (MASP-1) has a central role in the lectin pathway of complement activation and is required for the formation of C3 convertase. The activity of MASP-1 in the peripheral blood has been identified previously as a highly significant predictor of the severity of liver fibrosis in hepatitis C virus (HCV) infection, but not in liver disease of other aetiologies. In this study we tested the hypotheses that expression of MASP-1 may promote disease progression in HCV disease by direct activation of hepatic stellate cells (HSCs) and may additionally be up-regulated by HCV. In order to do so, we utilized a model for the maintenance of primary human HSC in the quiescent state by culture on basement membrane substrate prior to stimulation. In comparison to controls, recombinant MASP-1 stimulated quiescent human HSCs to differentiate to the activated state as assessed by both morphology and up-regulation of HSC activation markers α-smooth muscle actin and tissue inhibitor of metalloproteinase 1. Further, the expression of MASP-1 was up-regulated significantly by HCV infection in hepatocyte cell lines. These observations suggest a new role for MASP-1 and provide a possible mechanistic link between high levels of MASP-1 and the severity of disease in HCV infection. Taken together with previous clinical observations, our new findings suggest that the balance of MASP-1 activity may be proinflammatory and act to accelerate fibrosis progression in HCV liver disease.
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Affiliation(s)
- A Saeed
- School of Molecular Medical Sciences, University of Nottingham, Leicester, UK; School of Pharmacy, University of Nottingham, Leicester, UK
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26
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Huang J, Zhang Q, Li GZ, Haddleton DM, Wallis R, Mitchell D, Heise A, Becer CR. Macromol. Rapid Commun. 19/2013. Macromol Rapid Commun 2013. [DOI: 10.1002/marc.201370063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Jin Huang
- School of Chemical Science; Dublin City University; Dublin 9 Ireland
| | - Qiang Zhang
- Department of Chemistry; University of Warwick; Coventry CV4 7AL UK
| | - Guang-Zhao Li
- Department of Chemistry; University of Warwick; Coventry CV4 7AL UK
| | | | - Russell Wallis
- Department of Biochemistry; University of Leicester; Leicester LE1 9HN UK
| | - Daniel Mitchell
- Clinical Sciences Research Institute, Warwick Medical School; University of Warwick; Coventry CV2 2DX UK
| | - Andreas Heise
- School of Chemical Science; Dublin City University; Dublin 9 Ireland
| | - C. Remzi Becer
- Department of Chemistry; University of Warwick; Coventry CV4 7AL UK
- School of Engineering and Materials Science; Queen Mary University of London; Mile End Road London E1 4NS UK
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27
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Huang J, Zhang Q, Li GZ, Haddleton DM, Wallis R, Mitchell D, Heise A, Becer CR. Synthetic Glycopolypeptides as Potential Inhibitory Agents for Dendritic Cells and HIV-1 Trafficking. Macromol Rapid Commun 2013; 34:1542-6. [DOI: 10.1002/marc.201300439] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Revised: 07/09/2013] [Indexed: 01/10/2023]
Affiliation(s)
- Jin Huang
- School of Chemical Science; Dublin City University; Dublin; 9; Ireland
| | - Qiang Zhang
- Department of Chemistry; University of Warwick; Coventry; CV4 7AL; UK
| | - Guang-Zhao Li
- Department of Chemistry; University of Warwick; Coventry; CV4 7AL; UK
| | | | - Russell Wallis
- Department of Biochemistry; University of Leicester; Leicester; LE1 9HN; UK
| | - Daniel Mitchell
- Clinical Sciences Research Institute, Warwick Medical School; University of Warwick; Coventry; CV2 2DX; UK
| | - Andreas Heise
- School of Chemical Science; Dublin City University; Dublin; 9; Ireland
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28
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Keeling SE, Brosnahan CL, Johnston C, Wallis R, Gudkovs N, McDonald WL. Development and validation of a real-time PCR assay for the detection of Aeromonas salmonicida. J Fish Dis 2013; 36:495-503. [PMID: 23121198 DOI: 10.1111/jfd.12014] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2012] [Revised: 09/05/2012] [Accepted: 09/06/2012] [Indexed: 06/01/2023]
Abstract
A real-time PCR assay using a molecular beacon was developed and validated to detect the vapA (surface array protein) gene in the fish pathogen, Aeromonas salmonicida. The assay had 100% analytical specificity and analytical sensitivities of 5 ± 0 fg (DNA), 2.2 × 10(4) ± 1 × 10(4) CFU g(-1) (without enrichment) and 40 ± 10 CFU g(-1) (with enrichment) in kidney tissue. The assay was highly repeatable and proved to be robust following equivalency testing using a different real-time PCR platform. Following analytical validation, diagnostic specificity was determined using New Zealand farmed Chinook salmon, Oncorhynchus tshawytscha (Walbaum), (n = 750) and pink shubunkin, Carassius auratus (L.) (n = 157). The real-time PCR was run in parallel with culture and all fish tested were found to be negative by both methods for A. salmonicida, resulting in 100% diagnostic specificity (95% confidence interval). The molecular beacon real-time PCR system is specific, sensitive and a reproducible method for the detection of A. salmonicida. It can be used for diagnostic testing, health certification and active surveillance programmes.
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Affiliation(s)
- S E Keeling
- Animal Health Laboratory, Investigation and Diagnostic Centre - Wallaceville, Ministry for Primary Industries, Upper Hutt, New Zealand.
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29
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Schelenz S, Kirchhof N, Bidula S, Wallis R, Sexton DW. Opsonizing properties of rat ficolin-A in the defence against Cryptococcus neoformans. Immunobiology 2013; 218:477-83. [PMID: 22789560 DOI: 10.1016/j.imbio.2012.06.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2012] [Revised: 06/06/2012] [Accepted: 06/07/2012] [Indexed: 01/28/2023]
Abstract
Cryptococcus neoformans is a pathogenic fungus causing life threatening infections in humans. The present in vitro study aimed to investigate the opsonizing properties of a well characterized serum ficolin (rat ficolin-A), a member of carbohydrate-recognition molecules of the innate immune system, in the defence against this fungal pathogen. Using flow cytometric analysis we have been able to demonstrate that ficolin-A readily binds to two different acapsular C. neoformans serotypes (representative of the primary infectious form of this fungus) whereas the encapsulated forms are not being recognized. The ficolin-A binding was concentration dependent and inhibited by the acetylated sugars N-acetyleglucosamine and N-acetylegalactosamine but less so by galactose, glucose and mannan. The binding was enhanced at acidic pHs (5.7 and 4.7) compared to physiological pH (7.4) which may indicate that the carbohydrate recognizing fibrinogen-like domains of ficolins undergo conformational changes providing more efficient binding at sites of inflammation where the pH is much lower than normal. We further assessed the biological consequence of the ficolin-A recognition of acapsular C. neoformans by investigating their interaction with lung epithelial cells (type II pneumocytes cell line A549). Flow cytometric analysis demonstrated that ficolin-A opsonized acapsular C. neoformans showed significantly increased adherence to A549 cells when exposed to acidic conditions compared to the unopsonized controls (p=0.04). We conclude that ficolin-A binds acapsular C. neoformans via their carbohydrate recognizing fibrinogen-like domains leading to enhanced uptake by lung epithelial cells in vitro.
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Affiliation(s)
- Silke Schelenz
- Norwich Medical School, University of East Anglia, Norwich, United Kingdom.
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30
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Zhang Q, Collins J, Anastasaki A, Wallis R, Mitchell DA, Becer CR, Haddleton DM. Sequence-Controlled Multi-Block Glycopolymers to Inhibit DC-SIGN-gp120 Binding. Angew Chem Int Ed Engl 2013; 52:4435-9. [DOI: 10.1002/anie.201300068] [Citation(s) in RCA: 204] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Revised: 02/01/2013] [Indexed: 12/21/2022]
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31
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Ali YM, Lynch NJ, Haleem KS, Fujita T, Endo Y, Hansen S, Holmskov U, Takahashi K, Stahl GL, Dudler T, Girija UV, Wallis R, Kadioglu A, Stover CM, Andrew PW, Schwaeble WJ. The lectin pathway of complement activation is a critical component of the innate immune response to pneumococcal infection. PLoS Pathog 2012; 8:e1002793. [PMID: 22792067 PMCID: PMC3390405 DOI: 10.1371/journal.ppat.1002793] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2012] [Accepted: 05/23/2012] [Indexed: 01/19/2023] Open
Abstract
The complement system plays a key role in host defense against pneumococcal infection. Three different pathways, the classical, alternative and lectin pathways, mediate complement activation. While there is limited information available on the roles of the classical and the alternative activation pathways of complement in fighting streptococcal infection, little is known about the role of the lectin pathway, mainly due to the lack of appropriate experimental models of lectin pathway deficiency. We have recently established a mouse strain deficient of the lectin pathway effector enzyme mannan-binding lectin associated serine protease-2 (MASP-2) and shown that this mouse strain is unable to form the lectin pathway specific C3 and C5 convertases. Here we report that MASP-2 deficient mice (which can still activate complement via the classical pathway and the alternative pathway) are highly susceptible to pneumococcal infection and fail to opsonize Streptococcus pneumoniae in the none-immune host. This defect in complement opsonisation severely compromises pathogen clearance in the lectin pathway deficient host. Using sera from mice and humans with defined complement deficiencies, we demonstrate that mouse ficolin A, human L-ficolin, and collectin 11 in both species, but not mannan-binding lectin (MBL), are the pattern recognition molecules that drive lectin pathway activation on the surface of S. pneumoniae. We further show that pneumococcal opsonisation via the lectin pathway can proceed in the absence of C4. This study corroborates the essential function of MASP-2 in the lectin pathway and highlights the importance of MBL-independent lectin pathway activation in the host defense against pneumococci.
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Affiliation(s)
- Youssif M. Ali
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom
- Faculty of Pharmacy, University of Mansoura, Mansoura, Egypt
| | - Nicholas J. Lynch
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom
| | - Kashif S. Haleem
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom
| | - Teizo Fujita
- Department of Immunology, Fukushima Medical University, Fukushima, Japan
| | - Yuichi Endo
- Department of Immunology, Fukushima Medical University, Fukushima, Japan
| | - Soren Hansen
- Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Uffe Holmskov
- Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Kazue Takahashi
- Department of Anesthesiology, Perioperative and Pain Medicine, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Gregory L. Stahl
- Department of Anesthesiology, Perioperative and Pain Medicine, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Thomas Dudler
- Omeros Corporation, Seattle, Washington, United States of America
| | - Umakhanth V. Girija
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom
| | - Russell Wallis
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom
| | - Aras Kadioglu
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom
| | - Cordula M. Stover
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom
| | - Peter W. Andrew
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom
| | - Wilhelm J. Schwaeble
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom
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32
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Beveridge AJ, Wallis R, Samani NJ. A molecular dynamics study of C1r and C1s dimers: implications for the structure of the C1 complex. Proteins 2012; 80:1987-97. [PMID: 22488778 DOI: 10.1002/prot.24087] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2011] [Revised: 03/14/2012] [Accepted: 03/16/2012] [Indexed: 11/10/2022]
Abstract
Complement is an important part of the immune system. It is initiated through three different pathways known as the classical, lectin, and alternative pathway. The multimolecular C1 complex of the classical pathway consists of a subcomponent, C1q, which binds to a tetramer comprising two C1r and two C1s proteases. A detailed description of the structure of the C1 complex is essential to fully understand how the complex acts on pathogens. A variety of different models have been proposed, which differ mainly in the way the proteases interact with C1q. In this study, we have used a combination of homology-based structure prediction and molecular dynamics to predict a partial structure of the C1s/C1r/C1r/C1s tetramer. For computational expediency the study was restricted to the CUB(1) -EGF-CUB(2) domains which are directly involved in the formation of the tetramer and its interaction with C1q; the catalytic fragments (CCP(1) -CCP(2) -SP), which mediate C1 activation and subsequent cleavage of substrates, were omitted. A systematic molecular dynamics (MD) study of several possible dimeric combinations suggest that the tetramer is formed when a pair of C1r/C1s dimers form a "doughnut" via a C1s/C1s head-to-tail interaction, which is stabilized by several putative salt bridges at the dimer interface. This result is consistent with biochemical data which have shown that self assembly requires the formation of C1r-C1s contacts and that electrostatic interactions play a key role. Furthermore, it identifies a number of putative binding residues that can be tested using site-directed mutagenesis.
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Affiliation(s)
- Allan J Beveridge
- Department of Cardiovascular Sciences, University of Leicester, Glenfield Hospital, Leicester, United Kingdom.
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33
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Gingras AR, Girija UV, Keeble AH, Panchal R, Mitchell DA, Moody PCE, Wallis R. Structural basis of mannan-binding lectin recognition by its associated serine protease MASP-1: implications for complement activation. Structure 2012; 19:1635-43. [PMID: 22078562 DOI: 10.1016/j.str.2011.08.014] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Revised: 08/04/2011] [Accepted: 08/17/2011] [Indexed: 01/19/2023]
Abstract
Complement activation contributes directly to health and disease. It neutralizes pathogens and stimulates immune processes. Defects lead to immunodeficiency and autoimmune diseases, whereas inappropriate activation causes self-damage. In the lectin and classical pathways, complement is triggered upon recognition of a pathogen by an activating complex. Here we present the first structure of such a complex in the form of the collagen-like domain of mannan-binding lectin (MBL) and the binding domain of its associated protease (MASP-1/-3). The collagen binds within a groove using a pivotal lysine side chain that interacts with Ca(2+)-coordinating residues, revealing the essential role of Ca(2+). This mode of binding is prototypic for all activating complexes of the lectin and classical pathways, and suggests a general mechanism for the global changes that drive activation. The structural insights reveal a new focus for inhibitors and we have validated this concept by targeting the binding pocket of the MASP.
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34
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Miller A, Phillips A, Gor J, Wallis R, Perkins SJ. Near-planar solution structures of mannose-binding lectin oligomers provide insight on activation of lectin pathway of complement. J Biol Chem 2012; 287:3930-45. [PMID: 22167201 PMCID: PMC3281675 DOI: 10.1074/jbc.m111.320341] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2011] [Revised: 12/01/2011] [Indexed: 12/03/2022] Open
Abstract
The complement system is a fundamental component of innate immunity that orchestrates complex immunological and inflammatory processes. Complement comprises over 30 proteins that eliminate invading microorganisms while maintaining host cell integrity. Protein-carbohydrate interactions play critical roles in both the activation and regulation of complement. Mannose-binding lectin (MBL) activates the lectin pathway of complement via the recognition of sugar arrays on pathogenic surfaces. To determine the solution structure of MBL, synchrotron x-ray scattering and analytical ultracentrifugation experiments showed that the carbohydrate-recognition domains in the MBL dimer, trimer, and tetramer are positioned close to each other in near-planar fan-like structures. These data were subjected to constrained modeling fits. A bent structure for the MBL monomer was identified starting from two crystal structures for its carbohydrate-recognition domain and its triple helical region. The MBL monomer structure was used to identify 10-12 near-planar solution structures for each of the MBL dimers, trimers, and tetramers starting from 900 to 6,859 randomized structures for each. These near-planar fan-like solution structures joined at an N-terminal hub clarified how the carbohydrate-recognition domain of MBL binds to pathogenic surfaces. They also provided insight on how MBL presents a structural template for the binding and auto-activation of the MBL-associated serine proteases to initiate the lectin pathway of complement activation.
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Affiliation(s)
- Ami Miller
- From the Department of Structural and Molecular Biology, Darwin Building, University College London, Gower Street, London, WC1E 6BT and
| | - Anna Phillips
- the Department of Infection, Immunity, and Inflammation, Medical Science Building, University of Leicester, University Road, Leicester, LE1 9HN, United Kingdom
| | - Jayesh Gor
- From the Department of Structural and Molecular Biology, Darwin Building, University College London, Gower Street, London, WC1E 6BT and
| | - Russell Wallis
- the Department of Infection, Immunity, and Inflammation, Medical Science Building, University of Leicester, University Road, Leicester, LE1 9HN, United Kingdom
| | - Stephen J. Perkins
- From the Department of Structural and Molecular Biology, Darwin Building, University College London, Gower Street, London, WC1E 6BT and
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35
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Keeling SE, Johnston C, Wallis R, Brosnahan CL, Gudkovs N, McDonald WL. Development and validation of real-time PCR for the detection of Yersinia ruckeri. J Fish Dis 2012; 35:119-125. [PMID: 22175801 DOI: 10.1111/j.1365-2761.2011.01327.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Yersiniosis (enteric red mouth disease) is a contagious bacterial disease caused by Yersinia ruckeri, which primarily affects salmonids. A real-time PCR assay using a molecular beacon has been developed and validated to improve the detection of the causative biotypes of Y. ruckeri. The assay, which targets the glnA (glutamine synthetase) gene, proved to have 100% analytical specificity and analytical sensitivities of 5 fg and 3 × 10(3) CFU g(-1) for DNA and seeded kidney tissue, respectively. The assay was highly repeatable with low % CV for intra- and inter-run experiments, and the optimized parameters transferred easily between different real-time PCR platforms. Following analytical validation, diagnostic specificity was determined using New Zealand farmed Chinook salmon (n = 750) from 10 farms during 2007/08. The real-time PCR was run in parallel with the bacterial culture detection method, and all fish tested were found to be negative by both methods for Y. ruckeri, resulting in 100% diagnostic specificity (95% confidence interval). The molecular beacon real-time PCR system is specific, sensitive, reproducible and a rapid method for the detection of Y. ruckeri and has the potential to be used for routine diagnostic testing, health certification and active surveillance programmes.
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Affiliation(s)
- S E Keeling
- Animal Health Laboratory, Investigation and Diagnostic Centre - Wallaceville, MAF Biosecurity New Zealand, Upper Hutt, New Zealand.
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Laverty H, Benson C, Cartwright E, Cross M, Garland C, Hammond T, Holloway C, McMahon N, Milligan J, Park B, Pirmohamed M, Pollard C, Radford J, Roome N, Sager P, Singh S, Suter T, Suter W, Trafford A, Volders P, Wallis R, Weaver R, York M, Valentin J. How can we improve our understanding of cardiovascular safety liabilities to develop safer medicines? Br J Pharmacol 2011; 163:675-93. [PMID: 21306581 DOI: 10.1111/j.1476-5381.2011.01255.x] [Citation(s) in RCA: 246] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Given that cardiovascular safety liabilities remain a major cause of drug attrition during preclinical and clinical development, adverse drug reactions, and post-approval withdrawal of medicines, the Medical Research Council Centre for Drug Safety Science hosted a workshop to discuss current challenges in determining, understanding and addressing 'Cardiovascular Toxicity of Medicines'. This article summarizes the key discussions from the workshop that aimed to address three major questions: (i) what are the key cardiovascular safety liabilities in drug discovery, drug development and clinical practice? (ii) how good are preclinical and clinical strategies for detecting cardiovascular liabilities? and (iii) do we have a mechanistic understanding of these liabilities? It was concluded that in order to understand, address and ultimately reduce cardiovascular safety liabilities of new therapeutic agents there is an urgent need to: • Fully characterize the incidence, prevalence and impact of drug-induced cardiovascular issues at all stages of the drug development process. • Ascertain the predictive value of existing non-clinical models and assays towards the clinical outcome. • Understand the mechanistic basis of cardiovascular liabilities; by addressing areas where it is currently not possible to predict clinical outcome based on preclinical safety data. • Provide scientists in all disciplines with additional skills to enable them to better integrate preclinical and clinical data and to better understand the biological and clinical significance of observed changes. • Develop more appropriate, highly relevant and predictive tools and assays to identify and wherever feasible to eliminate cardiovascular safety liabilities from molecules and wherever appropriate to develop clinically relevant and reliable safety biomarkers.
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Affiliation(s)
- Hg Laverty
- MRC Centre for Drug Safety Science, Department of Molecular and Clinical Pharmacology, The University of Liverpool, Merseyside, UK
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Coopman K, Wallis R, Robb G, Brown AJH, Wilkinson GF, Timms D, Willars GB. Residues within the transmembrane domain of the glucagon-like peptide-1 receptor involved in ligand binding and receptor activation: modelling the ligand-bound receptor. Mol Endocrinol 2011; 25:1804-18. [PMID: 21868452 DOI: 10.1210/me.2011-1160] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The C-terminal regions of glucagon-like peptide-1 (GLP-1) bind to the N terminus of the GLP-1 receptor (GLP-1R), facilitating interaction of the ligand N terminus with the receptor transmembrane domain. In contrast, the agonist exendin-4 relies less on the transmembrane domain, and truncated antagonist analogs (e.g. exendin 9-39) may interact solely with the receptor N terminus. Here we used mutagenesis to explore the role of residues highly conserved in the predicted transmembrane helices of mammalian GLP-1Rs and conserved in family B G protein coupled receptors in ligand binding and GLP-1R activation. By iteration using information from the mutagenesis, along with the available crystal structure of the receptor N terminus and a model of the active opsin transmembrane domain, we developed a structural receptor model with GLP-1 bound and used this to better understand consequences of mutations. Mutation at Y152 [transmembrane helix (TM) 1], R190 (TM2), Y235 (TM3), H363 (TM6), and E364 (TM6) produced similar reductions in affinity for GLP-1 and exendin 9-39. In contrast, other mutations either preferentially [K197 (TM2), Q234 (TM3), and W284 (extracellular loop 2)] or solely [D198 (TM2) and R310 (TM5)] reduced GLP-1 affinity. Reduced agonist affinity was always associated with reduced potency. However, reductions in potency exceeded reductions in agonist affinity for K197A, W284A, and R310A, while H363A was uncoupled from cAMP generation, highlighting critical roles of these residues in translating binding to activation. Data show important roles in ligand binding and receptor activation of conserved residues within the transmembrane domain of the GLP-1R. The receptor structural model provides insight into the roles of these residues.
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Affiliation(s)
- K Coopman
- Department of Cell Physiology and Pharmacology, University of Leicester, Leicester, United Kingdom
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Abstract
OBJECTIVES The UK Newborn Screening Programme has standards to facilitate the early identification and treatment of five specific diseases to prevent lifelong impairment or death. This audit aimed to assess the newborn bloodspot screening programme in an inner London borough and to make recommendations for service improvement. METHODS Data on babies registered with a general practitioner in the borough between April 2008 and March 2009 were obtained from the borough's health database and the laboratory result systems and compared with national screening standards. Interviews were conducted with the leads of each service providing components of newborn screening. RESULTS A total of 292 (8%) out of 3636 babies registered within the audit period had no result on the database (average 1 in 13). Regional reports revealed that over the previous three years the borough, like many others, had consistently failed to achieve the core standards for newborn bloodspot screening. Major areas of concern identified by this audit pertained to the quality of the bloodspot sample, response to requests for repeat samples, timely identification of untested babies and communication of results to parents. CONCLUSION The audit revealed that for the majority of children registered in the borough, screening was successfully carried out. However, gaps in the service meant that with current practice one affected child could be missed every seven years. Recommendations include staff training, frequent data reviews, and providing a coordinating officer to oversee the programme and follow up missing results.
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Affiliation(s)
- S Bello
- Public Health Medicine, Lambeth Primary Care Trust, London, UK.
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Girija UV, Mitchell DA, Roscher S, Wallis R. Carbohydrate recognition and complement activation by rat ficolin-B. Eur J Immunol 2011; 41:214-23. [PMID: 21182092 PMCID: PMC3179595 DOI: 10.1002/eji.201040612] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Revised: 08/12/2010] [Accepted: 10/08/2010] [Indexed: 12/19/2022]
Abstract
Ficolins are innate immune components that bind to PAMPs and structures on apoptotic cells. Humans produce two serum forms (L- and H-ficolin) and a leukocyte-associated form (M-ficolin), whereas rodents and most other mammals produce ficolins-A and -B, orthologues of L- and M-ficolin, respectively. All three human ficolins, together with mouse and rat ficolin-A, associate with mannan-binding lectin-associated serine proteases (MASPs) and activate the lectin pathway of complement on PAMPs. By contrast, mouse ficolin-B does not bind MASPs and cannot activate complement. Because of these striking differences together with the lack of functional information for other ficolin-B orthologues, we have characterized rat ficolin-B, and compared its physical and biochemical properties with its serum counterpart. The data show that both rat ficolins have archetypal structures consisting of oligomers of a trimeric subunit. Ficolin-B recognized mainly sialyated sugars, characteristic of exogenous and endogenous ligands, whereas ficolin-A had a surprisingly narrow specificity, binding strongly to only one of 320 structures tested: an N-acetylated trisaccharide. Surprisingly, rat ficolin-B activated MASP-2 comparable to ficolin-A. Mutagenesis data reveal that lack of activity in mouse ficolin-B is probably caused by a single amino acid change in the putative MASP-binding site that blocks the ficolin-MASP interaction.
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Affiliation(s)
| | - Daniel A Mitchell
- Clinical Sciences Research Institute, University of WarwickWarwick, UK
| | - Silke Roscher
- Department of Infection, Immunity and Inflammation, University of LeicesterLeicester, UK
| | - Russell Wallis
- Department of Infection, Immunity and Inflammation, University of LeicesterLeicester, UK
- Department of Biochemistry, University of LeicesterLeicester, UK
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Becer CR, Gibson MI, Geng J, Ilyas R, Wallis R, Mitchell DA, Haddleton DM. High-affinity glycopolymer binding to human DC-SIGN and disruption of DC-SIGN interactions with HIV envelope glycoprotein. J Am Chem Soc 2010; 132:15130-2. [PMID: 20932025 PMCID: PMC3091610 DOI: 10.1021/ja1056714] [Citation(s) in RCA: 172] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2010] [Indexed: 01/18/2023]
Abstract
Noncovalent interactions between complex carbohydrates and proteins drive many fundamental processes within biological systems, including human immunity. In this report we aimed to investigate the potential of mannose-containing glycopolymers to interact with human DC-SIGN and the ability of these glycopolymers to inhibit the interactions between DC-SIGN and the HIV envelope glycoprotein gp120. We used a library of glycopolymers that are prepared via combination of copper-mediated living radical polymerization and azide-alkyne [3+2] Huisgen cycloaddition reaction. We demonstrate that a relatively simple glycopolymer can effectively prevent the interactions between a human dendritic cell associated lectin (DC-SIGN) and the viral envelope glycoprotein gp120. This approach may give rise to novel insights into the mechanisms of HIV infection and provide potential new therapeutics.
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Ilyas R, Wallis R, Soilleux EJ, Townsend P, Zehnder D, Tan BK, Sim RB, Lehnert H, Randeva HS, Mitchell DA. High glucose disrupts oligosaccharide recognition function via competitive inhibition: a potential mechanism for immune dysregulation in diabetes mellitus. Immunobiology 2010; 216:126-31. [PMID: 20674073 DOI: 10.1016/j.imbio.2010.06.002] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2010] [Revised: 06/08/2010] [Accepted: 06/08/2010] [Indexed: 12/11/2022]
Abstract
Diabetic complications include infection and cardiovascular disease. Within the immune system, host-pathogen and regulatory host-host interactions operate through binding of oligosaccharides by C-type lectin. A number of C-type lectins recognise oligosaccharides rich in mannose and fucose - sugars with similar structures to glucose. This raises the possibility that high glucose conditions in diabetes affect protein-oligosaccharide interactions via competitive inhibition. Mannose-binding lectin, soluble DC-SIGN and DC-SIGNR, and surfactant protein D, were tested for carbohydrate binding in the presence of glucose concentrations typical of diabetes, via surface plasmon resonance and affinity chromatography. Complement activation assays were performed in high glucose. DC-SIGN and DC-SIGNR expression in adipose tissues was examined via immunohistochemistry. High glucose inhibited C-type lectin binding to high-mannose glycoprotein and binding of DC-SIGN to fucosylated ligand (blood group B) was abrogated in high glucose. Complement activation via the lectin pathway was inhibited in high glucose and also in high trehalose - a nonreducing sugar with glucoside stereochemistry. DC-SIGN staining was seen on cells with DC morphology within omental and subcutaneous adipose tissues. We conclude that high glucose disrupts C-type lectin function, potentially illuminating new perspectives on susceptibility to infectious and inflammatory disease in diabetes. Mechanisms involve competitive inhibition of carbohydrate binding within sets of defined proteins, in contrast to broadly indiscriminate, irreversible glycation of proteins.
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Affiliation(s)
- Rebecca Ilyas
- Clinical Sciences Research Institute, University of Warwick, UK
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43
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Venkatraman Girija U, Furze C, Toth J, Schwaeble WJ, Mitchell DA, Keeble AH, Wallis R. Engineering novel complement activity into a pulmonary surfactant protein. J Biol Chem 2010; 285:10546-52. [PMID: 20118239 PMCID: PMC2856262 DOI: 10.1074/jbc.m109.097493] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Complement neutralizes invading pathogens, stimulates inflammatory and adaptive immune responses, and targets non- or altered-self structures for clearance. In the classical and lectin activation pathways, it is initiated when complexes composed of separate recognition and activation subcomponents bind to a pathogen surface. Despite its apparent complexity, recognition-mediated activation has evolved independently in three separate protein families, C1q, mannose-binding lectins (MBLs), and serum ficolins. Although unrelated, all have bouquet-like architectures and associate with complement-specific serine proteases: MBLs and ficolins with MBL-associated serine protease-2 (MASP-2) and C1q with C1r and C1s. To examine the structural requirements for complement activation, we have created a number of novel recombinant rat MBLs in which the position and orientation of the MASP-binding sites have been changed. We have also engineered MASP binding into a pulmonary surfactant protein (SP-A), which has the same domain structure and architecture as MBL but lacks any intrinsic complement activity. The data reveal that complement activity is remarkably tolerant to changes in the size and orientation of the collagenous stalks of MBL, implying considerable rotational and conformational flexibility in unbound MBL. Furthermore, novel complement activity is introduced concurrently with MASP binding in SP-A but is uncontrolled and occurs even in the absence of a carbohydrate target. Thus, the active rather than the zymogen state is default in lectin·MASP complexes and must be inhibited through additional regions in circulating MBLs until triggered by pathogen recognition.
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Thomsen T, Moeller JB, Schlosser A, Sorensen GL, Moestrup SK, Palaniyar N, Wallis R, Mollenhauer J, Holmskov U. The recognition unit of FIBCD1 organizes into a noncovalently linked tetrameric structure and uses a hydrophobic funnel (S1) for acetyl group recognition. J Biol Chem 2009; 285:1229-38. [PMID: 19892701 DOI: 10.1074/jbc.m109.061523] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We have recently identified FIBCD1 (Fibrinogen C domain containing 1) as a type II transmembrane endocytic receptor located primarily in the intestinal brush border. The ectodomain of FIBCD1 comprises a coiled coil, a polycationic region, and a C-terminal FReD (fibrinogen-related domain) that assembles into disulfide-linked homotetramers. The FIBCD1-FReD binds Ca(2+) dependently to acetylated structures like chitin, N-acetylated carbohydrates, and amino acids. FReDs are present in diverse innate immune pattern recognition proteins including the ficolins and horseshoe crab TL5A. Here, we use chemical cross-linking, combined with analytical ultracentrifugation and electron microscopy of the negatively stained recombinant FIBCD1-FReD to show that it assembles into noncovalent tetramers in the absence of the coiled coil. We use surface plasmon resonance, carbohydrate binding, and pulldown assays combined with site-directed mutagenesis to define the binding site involved in the interaction of FIBCD1 with acetylated structures. We show that mutations of central residues (A432V and H415G) in the hydrophobic funnel (S1) abolish the binding of FIBCD1 to acetylated bovine serum albumin and chitin. The double mutations (D393N/D395A) at the putative calcium-binding site reduce the ability of FIBCD1 to bind ligands. We conclude that the FReDs of FIBCD1 forms noncovalent tetramers and that the acetyl-binding site of FReDs of FIBCD1 is homologous to that of tachylectin 5A and M-ficolin but not to the FReD of L-ficolin. We suggest that the spatial organization of the FIBCD1-FReDs determine the molecular pattern recognition specificity and subsequent biological functions.
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Affiliation(s)
- Theresa Thomsen
- Medical Biotechnology Center, University of Southern Denmark, 5000 Odense, Denmark
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45
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Wallis R, Mitchell DA, Schmid R, Schwaeble WJ, Keeble AH. Paths reunited: Initiation of the classical and lectin pathways of complement activation. Immunobiology 2009; 215:1-11. [PMID: 19783065 DOI: 10.1016/j.imbio.2009.08.006] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2009] [Accepted: 08/22/2009] [Indexed: 12/16/2022]
Abstract
Understanding the structural organisation and mode of action of the initiating complex of the classical pathway of complement activation (C1) has been a central goal in complement biology since its isolation almost 50 years ago. Nevertheless, knowledge is still incomplete, especially with regard to the interactions between its subcomponents C1q, C1r and C1s that trigger activation upon binding to a microbial target. Recent studies have provided new insights into these interactions, and have revealed unexpected parallels with initiating complexes of the lectin pathway of complement: MBL-MASP and ficolin-MASP. Here, we develop and expand these concepts and delineate their implications towards the key aspects of complement activation via the classical and lectin pathways.
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Affiliation(s)
- Russell Wallis
- Department of Infection, Immunity and Inflammation, University of Leicester, UK.
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46
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Phillips AE, Toth J, Dodds AW, Girija UV, Furze CM, Pala E, Sim RB, Reid KBM, Schwaeble WJ, Schmid R, Keeble AH, Wallis R. Analogous interactions in initiating complexes of the classical and lectin pathways of complement. J Immunol 2009; 182:7708-17. [PMID: 19494295 DOI: 10.4049/jimmunol.0900666] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The classical and lectin pathways of complement activation neutralize pathogens and stimulate key immunological processes. Both pathways are initiated by collagen-containing, soluble pattern recognition molecules associated with specific serine proteases. In the classical pathway, C1q binds to Ab-Ag complexes or bacterial surfaces to activate C1r and C1s. In the lectin pathway, mannan-binding lectin and ficolins bind to carbohydrates on pathogens to activate mannan-binding lectin-associated serine protease 2. To characterize the interactions leading to classical pathway activation, we have analyzed binding between human C1q, C1r, and C1s, which associate to form C1, using full-length and truncated protease components. We show that C1r and C1s bind to C1q independently. The CUB1-epidermal growth factor fragments contribute most toward binding, but CUB2 of C1r, but not of C1s, is also important. Each C1rs tetramer presents a total of six binding sites, one for each of the collagenous domains of C1q. We also demonstrate that subcomponents of the lectin and classical pathways cross-interact. Thus, although the stoichiometries of complexes differ, interactions are analogous, with equivalent contacts between recognition and protease subcomponents. Importantly, these new data are contrary to existing models of C1 and enable us to propose a new model using mannan-binding lectin-mannan-binding lectin-associated serine protease interactions as a template.
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Affiliation(s)
- Anna E Phillips
- Department of Infection, University of Leicester, Leicester, United Kingdom
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Färber K, Cheung G, Mitchell D, Wallis R, Weihe E, Schwaeble W, Kettenmann H. C1q, the recognition subcomponent of the classical pathway of complement, drives microglial activation. J Neurosci Res 2009; 87:644-52. [PMID: 18831010 DOI: 10.1002/jnr.21875] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Microglia, central nervous system (CNS) resident phagocytic cells, persistently police the integrity of CNS tissue and respond to any kind of damage or pathophysiological changes. These cells sense and rapidly respond to danger and inflammatory signals by changing their cell morphology; by release of cytokines, chemokines, or nitric oxide; and by changing their MHC expression profile. We have shown previously that microglial biosynthesis of the complement subcomponent C1q may serve as a reliable marker of microglial activation ranging from undetectable levels of C1q biosynthesis in resting microglia to abundant C1q expression in activated, nonramified microglia. In this study, we demonstrate that cultured microglial cells respond to extrinsic C1q with a marked intracellular Ca(2+) increase. A shift toward proinflammatory microglial activation is indicated by the release of interleukin-6, tumor necrosis factor-alpha, and nitric oxide and the oxidative burst in rat primary microglial cells, an activation and differentiation process similar to the proinflammatory response of microglia to exposure to lipopolysaccharide. Our findings indicate 1) that extrinsic plasma C1q is involved in the initiation of microglial activation in the course of CNS diseases with blood-brain barrier impairment and 2) that C1q synthesized and released by activated microglia is likely to contribute in an autocrine/paracrine way to maintain and balance microglial activation in the diseased CNS tissue.
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Affiliation(s)
- Katrin Färber
- Cellular Neuroscience, Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
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48
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Miller A, Phillips A, Wallis R, Perkins S. Structural molecular modelling of the monomer, dimer, trimer and tetramer forms of mannose-binding lectin. Mol Immunol 2008. [DOI: 10.1016/j.molimm.2008.08.124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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49
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Girija UV, Dodds A, Reid K, Wallis R. Molecular characterisation of the interactions in the initiating complexes of the lectin pathway of complement activation. Mol Immunol 2008. [DOI: 10.1016/j.molimm.2008.08.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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50
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Geng J, Mantovani G, Tao L, Nicolas J, Chen G, Wallis R, Mitchell DA, Johnson BRG, Evans SD, Haddleton DM. Site-Directed Conjugation of “Clicked” Glycopolymers To Form Glycoprotein Mimics: Binding to Mammalian Lectin and Induction of Immunological Function. J Am Chem Soc 2007; 129:15156-63. [DOI: 10.1021/ja072999x] [Citation(s) in RCA: 269] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Jin Geng
- Contribution from the Department of Chemistry, University of Warwick, CV4 7AL, Coventry, United Kingdom; Clinical Sciences Research Institute, Warwick Medical School, University of Warwick, CV2 2DX, Coventry, United Kingdom; Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom; and School of Physics and Astronomy, University of Leeds, Leeds, United Kingdom
| | - Giuseppe Mantovani
- Contribution from the Department of Chemistry, University of Warwick, CV4 7AL, Coventry, United Kingdom; Clinical Sciences Research Institute, Warwick Medical School, University of Warwick, CV2 2DX, Coventry, United Kingdom; Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom; and School of Physics and Astronomy, University of Leeds, Leeds, United Kingdom
| | - Lei Tao
- Contribution from the Department of Chemistry, University of Warwick, CV4 7AL, Coventry, United Kingdom; Clinical Sciences Research Institute, Warwick Medical School, University of Warwick, CV2 2DX, Coventry, United Kingdom; Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom; and School of Physics and Astronomy, University of Leeds, Leeds, United Kingdom
| | - Julien Nicolas
- Contribution from the Department of Chemistry, University of Warwick, CV4 7AL, Coventry, United Kingdom; Clinical Sciences Research Institute, Warwick Medical School, University of Warwick, CV2 2DX, Coventry, United Kingdom; Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom; and School of Physics and Astronomy, University of Leeds, Leeds, United Kingdom
| | - Gaojian Chen
- Contribution from the Department of Chemistry, University of Warwick, CV4 7AL, Coventry, United Kingdom; Clinical Sciences Research Institute, Warwick Medical School, University of Warwick, CV2 2DX, Coventry, United Kingdom; Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom; and School of Physics and Astronomy, University of Leeds, Leeds, United Kingdom
| | - Russell Wallis
- Contribution from the Department of Chemistry, University of Warwick, CV4 7AL, Coventry, United Kingdom; Clinical Sciences Research Institute, Warwick Medical School, University of Warwick, CV2 2DX, Coventry, United Kingdom; Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom; and School of Physics and Astronomy, University of Leeds, Leeds, United Kingdom
| | - Daniel A. Mitchell
- Contribution from the Department of Chemistry, University of Warwick, CV4 7AL, Coventry, United Kingdom; Clinical Sciences Research Institute, Warwick Medical School, University of Warwick, CV2 2DX, Coventry, United Kingdom; Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom; and School of Physics and Astronomy, University of Leeds, Leeds, United Kingdom
| | - Benjamin R. G. Johnson
- Contribution from the Department of Chemistry, University of Warwick, CV4 7AL, Coventry, United Kingdom; Clinical Sciences Research Institute, Warwick Medical School, University of Warwick, CV2 2DX, Coventry, United Kingdom; Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom; and School of Physics and Astronomy, University of Leeds, Leeds, United Kingdom
| | - Stephen D. Evans
- Contribution from the Department of Chemistry, University of Warwick, CV4 7AL, Coventry, United Kingdom; Clinical Sciences Research Institute, Warwick Medical School, University of Warwick, CV2 2DX, Coventry, United Kingdom; Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom; and School of Physics and Astronomy, University of Leeds, Leeds, United Kingdom
| | - David M. Haddleton
- Contribution from the Department of Chemistry, University of Warwick, CV4 7AL, Coventry, United Kingdom; Clinical Sciences Research Institute, Warwick Medical School, University of Warwick, CV2 2DX, Coventry, United Kingdom; Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom; and School of Physics and Astronomy, University of Leeds, Leeds, United Kingdom
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