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Yang J, Yuan X, Hao Y, Shi X, Yang X, Yan W, Chen L, Zhang D, Shen C, Li D, Zhu Z, Liu X, Zheng H, Zhang K. Proteins in pregnant swine serum promote the African swine fever virus replication: an iTRAQ-based quantitative proteomic analysis. Virol J 2023; 20:54. [PMID: 36978180 PMCID: PMC10043535 DOI: 10.1186/s12985-023-02004-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Accepted: 03/03/2023] [Indexed: 03/30/2023] Open
Abstract
African swine fever (ASF) is a severe infectious disease caused by the African swine fever virus (ASFV), seriously endangering the global pig industry. ASFV possesses a large genome, strong mutation ability, and complex immune escape mechanisms. Since the first case of ASF was reported in China in August 2018, it has had a significant impact on social economy and food safety. In the present study, pregnant swine serum (PSS) was found to promote viral replication; differentially expressed proteins (DEPs) in PSS were screened and identified using the isobaric tags for relative and absolute quantitation technology and compared with those in non-pregnant swine serum (NPSS). The DEPs were analyzed using Gene Ontology functional annotation, Kyoto Protocol Encyclopedia of Genes and Genome pathway enrichment, and protein-protein interaction networks. In addition, the DEPs were validated via western blot and RT-qPCR experiments. And the 342 of DEPs were identified in bone marrow-derived macrophages cultured with PSS compared with the NPSS. The 256 were upregulated and 86 of DEPs were downregulated. The primary biological functions of these DEPs involved signaling pathways that regulate cellular immune responses, growth cycles, and metabolism-related pathways. An overexpression experiment showed that the PCNA could promote ASFV replication whereas MASP1 and BST2 could inhibit it. These results further indicated that some protein molecules in PSS were involved in the regulation of ASFV replication. In the present study, the role of PSS in ASFV replication was analyzed using proteomics, and the study will be provided a basis for future detailed research on the pathogenic mechanism and host interactions of ASFV as well as new insights for the development of small-molecule compounds to inhibit ASFV.
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Affiliation(s)
- Jinke Yang
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730000, China
| | - Xingguo Yuan
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730000, China
| | - Yu Hao
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730000, China
| | - Xijuan Shi
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730000, China
| | - Xing Yang
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730000, China
| | - Wenqian Yan
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730000, China
| | - Lingling Chen
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730000, China
| | - Dajun Zhang
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730000, China
| | - Chaochao Shen
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730000, China
| | - Dan Li
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730000, China
| | - Zixiang Zhu
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730000, China
| | - Xiangtao Liu
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730000, China
| | - Haixue Zheng
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730000, China.
| | - Keshan Zhang
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730000, China.
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Sun J, Wang L, Song L. The primitive complement system in molluscs. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2023; 139:104565. [PMID: 36216083 DOI: 10.1016/j.dci.2022.104565] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Revised: 10/02/2022] [Accepted: 10/04/2022] [Indexed: 06/16/2023]
Abstract
The complement system is an important immune defense mechanism that plays essential roles in both innate and adaptive immunity of vertebrates. Since complement components are identified in deuterostome and even primitive protostome species, the origin and evolution of complement system in invertebrates have been of great interest. Recently, research on the complement system in mollusc immunity has been increasing due to their importance in worldwide aquaculture, and their phylogenetic position. Complement components including C3, C1q domain containing protein (C1qDCP), C-type lectin (CTL), ficolin-like, mannose-binding lectin (MBL)-associated serine proteases like (MASPL), and factor B have been identified, suggesting the existence of complement system in molluscs. The lectin pathway has been outlined in molluscs, which is initiated by CTL with CCP domain and MASPL protein to generate C3 cleavage fragments. The molluscan C1qDCP exhibits the capability to bind human IgG, indicating the existence of possible C1qDCP-mediated activation pathway in molluscs. The activation of C3 regulates the expressions of immune effectors (cytokines and antibacterial peptides), mediates the haemocyte phagocytosis, and inhibits the bacterial growth. Some MACPF domain containing proteins may replace the missing terminal pathway in molluscs. This article provides a review of complement system in molluscs, including its components, activation mechanisms and functions in the immune response of molluscs.
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Affiliation(s)
- Jiejie Sun
- Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian, 116023, China; Liaoning Key Laboratory of Marine Animal Immunology & Disease Control, Dalian Ocean University, Dalian, 116023, China
| | - Lingling Wang
- Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian, 116023, China; Laboratory of Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266235, China; Liaoning Key Laboratory of Marine Animal Immunology & Disease Control, Dalian Ocean University, Dalian, 116023, China; Dalian Key Laboratory of Aquatic Animal Disease Control, Dalian Ocean University, Dalian, 116023, China.
| | - Linsheng Song
- Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian, 116023, China; Laboratory of Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266235, China; Liaoning Key Laboratory of Marine Animal Immunology & Disease Control, Dalian Ocean University, Dalian, 116023, China
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Nagy ZA, Héja D, Bencze D, Kiss B, Boros E, Szakács D, Fodor K, Wilmanns M, Kocsis A, Dobó J, Gál P, Harmat V, Pál G. Synergy of protease-binding sites within the ecotin homodimer is crucial for inhibition of MASP enzymes and for blocking lectin pathway activation. J Biol Chem 2022; 298:101985. [PMID: 35483450 PMCID: PMC9136129 DOI: 10.1016/j.jbc.2022.101985] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 04/19/2022] [Accepted: 04/22/2022] [Indexed: 12/25/2022] Open
Abstract
Ecotin is a homodimeric serine protease inhibitor produced by many commensal and pathogenic microbes. It functions as a virulence factor, enabling survival of various pathogens in the blood. The ecotin dimer binds two protease molecules, and each ecotin protomer has two protease-binding sites: site1 occupies the substrate-binding groove, whereas site2 engages a distinct secondary region. Owing to the twofold rotational symmetry within the ecotin dimer, sites 1 and 2 of a protomer bind to different protease molecules within the tetrameric complex. Escherichia coli ecotin inhibits trypsin-like, chymotrypsin-like, and elastase-like enzymes, including pancreatic proteases, leukocyte elastase, key enzymes of blood coagulation, the contact and complement systems, and other antimicrobial cascades. Here, we show that mannan-binding lectin-associated serine protease-1 (MASP-1) and MASP-2, essential activators of the complement lectin pathway, and MASP-3, an essential alternative pathway activator, are all inhibited by ecotin. We decipher in detail how the preorganization of site1 and site2 within the ecotin dimer contributes to the inhibition of each MASP enzyme. In addition, using mutated and monomeric ecotin variants, we show that site1, site2, and dimerization contribute to inhibition in a surprisingly target-dependent manner. We present the first ecotin:MASP-1 and ecotin:MASP-2 crystal structures, which provide additional insights and permit structural interpretation of the observed functional results. Importantly, we reveal that monomerization completely disables the MASP-2-inhibitory, MASP-3-inhibitory, and lectin pathway-inhibitory capacity of ecotin. These findings provide new opportunities to combat dangerous multidrug-resistant pathogens through development of compounds capable of blocking ecotin dimer formation.
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Affiliation(s)
- Zoltán Attila Nagy
- Department of Biochemistry, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Dávid Héja
- Department of Biochemistry, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Dániel Bencze
- Department of Biochemistry, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Bence Kiss
- Department of Biochemistry, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Eszter Boros
- Department of Biochemistry, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Dávid Szakács
- Department of Biochemistry, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Krisztián Fodor
- Department of Biochemistry, ELTE Eötvös Loránd University, Budapest, Hungary,European Molecular Biology Laboratory, Hamburg Unit, Hamburg, Germany
| | - Matthias Wilmanns
- European Molecular Biology Laboratory, Hamburg Unit, Hamburg, Germany
| | - Andrea Kocsis
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, Hungary
| | - József Dobó
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, Hungary
| | - Péter Gál
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, Hungary
| | - Veronika Harmat
- Laboratory of Structural Chemistry and Biology, Institute of Chemistry, ELTE Eötvös Loránd University, Budapest, Hungary,MTA-ELTE Protein Modelling Research Group, ELKH, Budapest, Hungary
| | - Gábor Pál
- Department of Biochemistry, ELTE Eötvös Loránd University, Budapest, Hungary,For correspondence: Gábor Pál
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Ostrycharz E, Hukowska-Szematowicz B. New Insights into the Role of the Complement System in Human Viral Diseases. Biomolecules 2022; 12:226. [PMID: 35204727 PMCID: PMC8961555 DOI: 10.3390/biom12020226] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 01/23/2022] [Accepted: 01/27/2022] [Indexed: 01/27/2023] Open
Abstract
The complement system (CS) is part of the human immune system, consisting of more than 30 proteins that play a vital role in the protection against various pathogens and diseases, including viral diseases. Activated via three pathways, the classical pathway (CP), the lectin pathway (LP), and the alternative pathway (AP), the complement system leads to the formation of a membrane attack complex (MAC) that disrupts the membrane of target cells, leading to cell lysis and death. Due to the increasing number of reports on its role in viral diseases, which may have implications for research on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), this review aims to highlight significant progress in understanding and defining the role of the complement system in four groups of diseases of viral etiology: (1) respiratory diseases; (2) acute liver failure (ALF); (3) disseminated intravascular coagulation (DIC); and (4) vector-borne diseases (VBDs). Some of these diseases already present a serious global health problem, while others are a matter of concern and require the collaboration of relevant national services and scientists with the World Health Organization (WHO) to avoid their spread.
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Affiliation(s)
- Ewa Ostrycharz
- Institute of Biology, University of Szczecin, 71-412 Szczecin, Poland;
- Doctoral School of the University of Szczecin, University of Szczecin, 71-412 Szczecin, Poland
- Molecular Biology and Biotechnology Center, University of Szczecin, 71-412 Szczecin, Poland
| | - Beata Hukowska-Szematowicz
- Institute of Biology, University of Szczecin, 71-412 Szczecin, Poland;
- Molecular Biology and Biotechnology Center, University of Szczecin, 71-412 Szczecin, Poland
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5
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Biomaterial and cellular implants:foreign surfaces where immunity and coagulation meet. Blood 2021; 139:1987-1998. [PMID: 34415324 DOI: 10.1182/blood.2020007209] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 08/05/2021] [Indexed: 11/20/2022] Open
Abstract
Exposure of blood to a foreign surface in the form of a diagnostic or therapeutic biomaterial device or implanted cells or tissues, elicits an immediate, evolutionarily conserved thrombo-inflammatory response by the host. Primarily designed to protect against invading organisms following an injury, this innate response features instantaneous activation of several blood-borne, highly interactive and well-orchestrated cascades and cellular events that limit bleeding, destroy and eliminate the foreign substance/cells, and promote healing and a return to homeostasis via delicately balanced regenerative processes. In the setting of blood-contacting synthetic or natural biomaterials and implantation of foreign cells/tissues, innate responses are robust, albeit highly context-specific. Unfortunately, they tend to be less than adequately regulated by the host's natural anti-coagulant/anti-inflammatory pathways, thereby jeopardizing the functional integrity of the device, as well as the health of the host. Strategies to achieve biocompatibility with a sustained return to homeostasis, particularly while the device remains in situ and functional, continue to elude scientists and clinicians. In this review, some of the complex mechanisms by which biomaterials and cellular transplants provide a "hub" for activation and amplification of coagulation and immunity - thrombo-inflammation - will be discussed, with a view toward the development of innovative means of overcoming the innate challenges.
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Denesyuk AI, Johnson MS, Salo-Ahen OMH, Uversky VN, Denessiouk K. NBCZone: Universal three-dimensional construction of eleven amino acids near the catalytic nucleophile and base in the superfamily of (chymo)trypsin-like serine fold proteases. Int J Biol Macromol 2020; 153:399-411. [PMID: 32151723 PMCID: PMC7124590 DOI: 10.1016/j.ijbiomac.2020.03.025] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 03/02/2020] [Accepted: 03/03/2020] [Indexed: 10/25/2022]
Abstract
(Chymo)trypsin-like serine fold proteases belong to the serine/cysteine proteases found in eukaryotes, prokaryotes, and viruses. Their catalytic activity is carried out using a triad of amino acids, a nucleophile, a base, and an acid. For this superfamily of proteases, we propose the existence of a universal 3D structure comprising 11 amino acids near the catalytic nucleophile and base - Nucleophile-Base Catalytic Zone (NBCZone). The comparison of NBCZones among 169 eukaryotic, prokaryotic, and viral (chymo)trypsin-like proteases suggested the existence of 15 distinct groups determined by the combination of amino acids located at two "key" structure-functional positions 54T and 55T near the catalytic base His57T. Most eukaryotic and prokaryotic proteases fell into two major groups, [ST]A and TN. Usually, proteases of [ST]A group contain a disulfide bond between cysteines Cys42T and Cys58T of the NBCZone. In contrast, viral proteases were distributed among seven groups, and lack this disulfide bond. Furthermore, only the [ST]A group of eukaryotic proteases contains glycine at position 43T, which is instrumental for activation of these enzymes. In contrast, due to the side chains of residues at position 43T prokaryotic and viral proteases do not have the ability to carry out the structural transition of the eukaryotic zymogen-zyme type.
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Affiliation(s)
- Alexander I Denesyuk
- Institute for Biological Instrumentation of the Russian Academy of Sciences, Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", 142290 Pushchino, Russia; Structural Bioinformatics Laboratory, Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, 20520 Turku, Finland.
| | - Mark S Johnson
- Structural Bioinformatics Laboratory, Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, 20520 Turku, Finland
| | - Outi M H Salo-Ahen
- Structural Bioinformatics Laboratory, Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, 20520 Turku, Finland; Pharmaceutical Sciences Laboratory, Pharmacy, Faculty of Science and Engineering, Åbo Akademi University, 20520 Turku, Finland
| | - Vladimir N Uversky
- Institute for Biological Instrumentation of the Russian Academy of Sciences, Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", 142290 Pushchino, Russia; Department of Molecular Medicine and USF Health Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA.
| | - Konstantin Denessiouk
- Structural Bioinformatics Laboratory, Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, 20520 Turku, Finland; Pharmaceutical Sciences Laboratory, Pharmacy, Faculty of Science and Engineering, Åbo Akademi University, 20520 Turku, Finland
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Chen DD, Yao YY, Zhang YA. Identification and characterization of two mannan-binding lectin associated proteins in lectin complement pathway of grass carp. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2020; 103:103497. [PMID: 31518591 DOI: 10.1016/j.dci.2019.103497] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 09/09/2019] [Accepted: 09/09/2019] [Indexed: 06/10/2023]
Abstract
The lectin pathway of complement activation is an important component of the innate immune response, which must be tightly controlled to maintain immune homeostasis. However, its control mechanisms have not been investigated in detail in bony fish. In this study, we identified and characterized two novel, phylogenetically conserved mannan-binding lectin (MBL)-associated proteins (MAps) of grass carp (Ctenopharyngodon idella), CiMAp27 and CiMAp39, which were truncated, alternatively-spliced forms of grass carp MBL-associated serine proteases (MASPs), CiMASP1 and CiMASP2, respectively. Gene expression profiling showed that both CiMAp27 and CiMAp39 were upregulated by low doses of Aeromonas hydrophila, and inhibited by high doses, which lead to the inference that these genes acted as immune factors in antibacterial defense. Sequence analysis showed that CiMAp27 lack a catalytic domain but retains two domains (CUB1-EGF) involved in the association with MBL, while CiMAp39 retained four domains (CUB1-EGF-CUB2-CCP1). Not only the two CiMASPs but also the CiMAps were detected in grass carp serum. Furthermore, both recombinant CiMASPs (rCiMASPs) and recombinant rCiMAps (rCiMAps) interacted with recombinant MBL and the two CiMAps competed with CiMASPs for binding to MBL, and hence inhibited downstream C4 binding. These results indicated that CiMAps acted as competitive inhibitors in the lectin complement pathway of grass carp.
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Affiliation(s)
- Dan-Dan Chen
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China; Key Laboratory of Aquaculture Disease Control, Ministry of Agriculture, Wuhan, China
| | - Yuan-Yuan Yao
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China; University of Chinese Academy of Sciences, Beijing, China
| | - Yong-An Zhang
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China; State Key Laboratory of Agricultural Microbiology, College of Fisheries, Huazhong Agricultural University, Wuhan, China.
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Querino Lima Afonso M, da Fonseca NJ, de Oliveira LC, Lobo FP, Bleicher L. Coevolved Positions Represent Key Functional Properties in the Trypsin-Like Serine Proteases Protein Family. J Chem Inf Model 2020; 60:1060-1068. [DOI: 10.1021/acs.jcim.9b00903] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Marcelo Querino Lima Afonso
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Pres. Antônio Carlos, 6627 - Pampulha, Belo Horizonte, Minas Gerais, Brazil 31270-901
| | - Neli J. da Fonseca
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Pres. Antônio Carlos, 6627 - Pampulha, Belo Horizonte, Minas Gerais, Brazil 31270-901
| | - Lucas Carrijo de Oliveira
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Pres. Antônio Carlos, 6627 - Pampulha, Belo Horizonte, Minas Gerais, Brazil 31270-901
| | - Francisco Pereira Lobo
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Pres. Antônio Carlos, 6627 - Pampulha, Belo Horizonte, Minas Gerais, Brazil 31270-901
| | - Lucas Bleicher
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Pres. Antônio Carlos, 6627 - Pampulha, Belo Horizonte, Minas Gerais, Brazil 31270-901
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Arthur CM, Chonat S, Fasano R, Yee MEM, Josephson CD, Roback JD, Stowell SR. Examining the Role of Complement in Predicting, Preventing, and Treating Hemolytic Transfusion Reactions. Transfus Med Rev 2019; 33:217-224. [PMID: 31679762 PMCID: PMC7147990 DOI: 10.1016/j.tmrv.2019.09.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 09/04/2019] [Accepted: 09/05/2019] [Indexed: 12/24/2022]
Abstract
Red blood cell (RBC) transfusion is a critical component of optimal management for a broad range of conditions. Regardless of the indication, pretransfusion testing is required to appropriately match RBC donors and recipients to provide immunologically compatible blood. Although this approach is effective in the vast majority of situations, occasionally, patients will inadvertently receive an incompatible RBC transfusion, which can result in a hemolytic transfusion reaction (HTR). In addition, patients with life-threatening anemia and a complex alloantibody profile, which precludes rapid procurement of compatible RBCs, may also receive incompatible RBCs, placing them at risk for an HTR. Despite the rarity of these clinical situations, when incompatible blood transfusion results in an HTR, the consequences can be devastating. In this review, we will explore the challenges associated with actively preventing and treating acute HTRs following incompatible RBC transfusion. In doing so, we will focus primarily on the role of complement, not only as a key player in HTRs, but also as a potential target for the prevention and treatment of HTRs.
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Affiliation(s)
- Connie M Arthur
- Aflac Cancer and Blood Disorders Center, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA
| | - Satheesh Chonat
- Center for Transfusion Medicine and Cellular Therapies, Department of Laboratory Medicine and Pathology, Emory University School of Medicine, Atlanta, GA
| | - Ross Fasano
- Aflac Cancer and Blood Disorders Center, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA; Center for Transfusion Medicine and Cellular Therapies, Department of Laboratory Medicine and Pathology, Emory University School of Medicine, Atlanta, GA
| | - Marianne E M Yee
- Aflac Cancer and Blood Disorders Center, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA; Center for Transfusion Medicine and Cellular Therapies, Department of Laboratory Medicine and Pathology, Emory University School of Medicine, Atlanta, GA
| | - Cassandra D Josephson
- Aflac Cancer and Blood Disorders Center, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA; Center for Transfusion Medicine and Cellular Therapies, Department of Laboratory Medicine and Pathology, Emory University School of Medicine, Atlanta, GA
| | - John D Roback
- Center for Transfusion Medicine and Cellular Therapies, Department of Laboratory Medicine and Pathology, Emory University School of Medicine, Atlanta, GA
| | - Sean R Stowell
- Center for Transfusion Medicine and Cellular Therapies, Department of Laboratory Medicine and Pathology, Emory University School of Medicine, Atlanta, GA.
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Zhang H, Wei Y, Zhang F, Liu Y, Wang H, Li Y, Li G. Polymorphisms of mannose-binding lectin-associated serine protease 1 (MASP1) and its relationship with milk performance traits and complement activity in Chinese Holstein cattle. Res Vet Sci 2019; 124:346-351. [PMID: 31060014 DOI: 10.1016/j.rvsc.2019.04.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2019] [Revised: 03/16/2019] [Accepted: 04/22/2019] [Indexed: 10/27/2022]
Abstract
OBJECTIVE Mannose-binding lectin (MBL)-associated serine protease1 (MASP1) is the central enzyme in the innate immune system, which has biological functions of antibacterial and anti-inflammatory activities. Moreover, MASP1 represents a candidate gene reflecting the complement activity. This study is to investigate the entire exons of MASP1 in Chinese Holstein cattle with DNA sequencing to identify novel single nucleotide polymorphisms (SNPs). METHODS Novel SNPs were identified through gene sequencing and genotyped by the PCR Restriction Fragment Length Polymorphism (PCR-RFLP) and Created Restriction Site PCR (CRS-PCR). The relationship between the milk performance traits and complement activity in Chinese Holstein cattle was analyzed using the General Linear Model (GLM) procedure with the SAS software (version 8.0). RESULTS Two novel SNPs (i.e., g.5766A > G and g.51228A > C) were detected. The SNP g.5766A > G was located in the first intron and the SNP g.51228A > C was located in the 3'-untranslated regions of MASP1. The polymorphism at g.5766A > G was correlated with protein percentage (P < 0.05). Moreover, the polymorphism at g.51228A > C had only two genotypes, and this SNP had no significant correlation with CH50, ACH50, fat percentage, protein percentage, 305-day milk yields, or SCS scores. CONCLUSION MASP1, reflecting the complement activity, may not be significantly related to mastitis. However, MASP1 could be implemented in the breeding program to improve the production performance of Chinese Holstein cattle.
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Affiliation(s)
- Haiyan Zhang
- Department of Biochemistry, Heze Medical College, Heze 274000, Shandong Province, P. R. China; Dairy Cattle Research Center, Shandong Academy of Agricultural Science, Jinan 250131, Shandong Province, P. R. China.
| | - Yan Wei
- Department of Biochemistry, Heze Medical College, Heze 274000, Shandong Province, P. R. China
| | - Fengying Zhang
- Department of Biochemistry, Heze Medical College, Heze 274000, Shandong Province, P. R. China
| | - Yanyan Liu
- Department of Biochemistry, Heze Medical College, Heze 274000, Shandong Province, P. R. China
| | - Haifeng Wang
- Department of Biochemistry, Heze Medical College, Heze 274000, Shandong Province, P. R. China
| | - Yan Li
- Department of Biochemistry, Heze Medical College, Heze 274000, Shandong Province, P. R. China
| | - Ge Li
- Department of Biochemistry, Heze Medical College, Heze 274000, Shandong Province, P. R. China
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Szakács D, Kocsis A, Szász R, Gál P, Pál G. Novel MASP-2 inhibitors developed via directed evolution of human TFPI1 are potent lectin pathway inhibitors. J Biol Chem 2019; 294:8227-8237. [PMID: 30952698 PMCID: PMC6527154 DOI: 10.1074/jbc.ra119.008315] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 03/28/2019] [Indexed: 12/28/2022] Open
Abstract
The lectin pathway (LP) of the complement system is an important antimicrobial defense mechanism, but it also contributes significantly to ischemia reperfusion injury (IRI) associated with myocardial infarct, stroke, and several other clinical conditions. Mannan-binding lectin-associated serine proteinase 2 (MASP-2) is essential for LP activation, and therefore, it is a potential drug target. We have previously developed the first two generations of MASP-2 inhibitors by in vitro evolution of two unrelated canonical serine proteinase inhibitors. These inhibitors were selective LP inhibitors, but their nonhuman origin rendered them suboptimal lead molecules for drug development. Here, we present our third-generation MASP-2 inhibitors that were developed based on a human inhibitor scaffold. We subjected the second Kunitz domain of human tissue factor pathway inhibitor 1 (TFPI1 D2) to directed evolution using phage display to yield inhibitors against human and rat MASP-2. These novel TFPI1-based MASP-2 inhibitor (TFMI-2) variants are potent and selective LP inhibitors in both human and rat serum. Directed evolution of the first Kunitz domain of TFPI1 had already yielded the potent kallikrein inhibitor, Kalbitor® (ecallantide), which is an FDA-approved drug to treat acute attacks of hereditary angioedema. Like hereditary angioedema, acute IRI is also related to the uncontrolled activation of a specific plasma serine proteinase. Therefore, TFMI-2 variants are promising lead molecules for drug development against IRI.
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Affiliation(s)
- Dávid Szakács
- Department of Biochemistry, ELTE Eötvös Loránd University, Pázmány Péter sétány 1/C, H-1117 Budapest
| | - Andrea Kocsis
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2, H-1117 Budapest
| | - Róbert Szász
- Department of Hematology, Institute of Internal Medicine, University of Debrecen, Nagyerdei krt. 98, H-4032 Debrecen
| | - Péter Gál
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2, H-1117 Budapest
| | - Gábor Pál
- Department of Biochemistry, ELTE Eötvös Loránd University, Pázmány Péter sétány 1/C, H-1117 Budapest; EvolVeritas Biotechnology Ltd., Somogyi Béla u. 17, H-6600 Szentes, Hungary.
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Huang Y, Xu J, Wu X, Chen X, Bai X, Zhuang Y, Fang J, Lin X. High Expression of Complement Components in the Kidneys of Type 2 Diabetic Rats With Diabetic Nephropathy. Front Endocrinol (Lausanne) 2019; 10:459. [PMID: 31338070 PMCID: PMC6629834 DOI: 10.3389/fendo.2019.00459] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 06/25/2019] [Indexed: 12/14/2022] Open
Abstract
Background: Diabetic nephropathy (DN) is the leading cause of end-stage failure of the kidneys; however, its pathogenesis remains unknown. This study assessed the expression of complement components in the kidneys of rats with type 2 DN to investigate their role in DN. Methods: A rat model of type 2 DN was induced by a high-fat diet combined with low-dose streptozotocin. Blood glucose, fasting insulin levels, insulin resistance index, and 24-h urinary albumin excretion (UAE) were measured. Renal tissue morphological features were observed. The mesangial index and arteriosclerosis index were calculated. Immunohistochemistry and western blot were used to measure the expression of complement components in the kidneys. Results: The kidney weight: body weight (mg/g) ratio in the DN group was significantly greater than those in the control and diabetes mellitus (DM) groups. The arteriosclerosis index, mesangial index, and tube area percentage in the DN group were significantly higher than those in the control and DM groups, but these parameters did not significantly differ between the control and DM groups. The expression of the complement components C1q, mannose-binding lectin (MBL), mannan-binding lectin-associated serine protease (MASP)-2, B factor, C3, and C5b-9 in the DN group was significantly higher than that in the control and DM groups but did not significantly differ between the control and DM groups. Most of the complement components were mainly expressed at the renal tubular site. Correlation analysis showed that 24-h UAE were positively correlated with C1q, MBL, MASP-2, B factor, and C5b-9 expression. MI was positively correlated with MBL, B factor, C3, and C5b-9 expression. AI was positively correlated with C1q, MBL, MASP-2, and B factor expression. Conclusion: Complement components including C1q, MBL, MASP-2, B factor, C3, and C5b-9, were highly expressed in the kidneys of type 2 diabetic rats with DN. Most of the complement components were mainly expressed in the renal tubules. High expression of complement components was found to be associated with the progress of DN. Our study suggests that complement system activation is a progressive factor in type 2 diabetic nephropathy. Inhibition of pathological complement activation may be a promising therapeutic strategy for DN.
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Affiliation(s)
- Yinqiong Huang
- Department of Endocrinology, The Second Affiliated Hospital of Fujian Medical University, Quanzhou, China
| | - Jinting Xu
- Department of Endocrinology, Jinjiang Municipal Hospital, Jinjiang, China
| | - Xiaohong Wu
- Department of Endocrinology, The Second Affiliated Hospital of Fujian Medical University, Quanzhou, China
| | - Xiaoyu Chen
- Department of Endocrinology, The Second Affiliated Hospital of Fujian Medical University, Quanzhou, China
| | - Xuefeng Bai
- Department of Endocrinology, The Second Affiliated Hospital of Fujian Medical University, Quanzhou, China
| | - Yong Zhuang
- Department of Endocrinology, The Second Affiliated Hospital of Fujian Medical University, Quanzhou, China
| | - Jingwen Fang
- Department of Endocrinology, The Second Affiliated Hospital of Fujian Medical University, Quanzhou, China
| | - Xiahong Lin
- Department of Endocrinology, The Second Affiliated Hospital of Fujian Medical University, Quanzhou, China
- *Correspondence: Xiahong Lin
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Dobó J, Kocsis A, Gál P. Be on Target: Strategies of Targeting Alternative and Lectin Pathway Components in Complement-Mediated Diseases. Front Immunol 2018; 9:1851. [PMID: 30135690 PMCID: PMC6092519 DOI: 10.3389/fimmu.2018.01851] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 07/26/2018] [Indexed: 12/20/2022] Open
Abstract
The complement system has moved into the focus of drug development efforts in the last decade, since its inappropriate or uncontrolled activation has been recognized in many diseases. Some of them are primarily complement-mediated rare diseases, such as paroxysmal nocturnal hemoglobinuria, C3 glomerulonephritis, and atypical hemolytic uremic syndrome. Complement also plays a role in various multifactorial diseases that affect millions of people worldwide, such as ischemia reperfusion injury (myocardial infarction, stroke), age-related macular degeneration, and several neurodegenerative disorders. In this review, we summarize the potential advantages of targeting various complement proteins with special emphasis on the components of the lectin (LP) and the alternative pathways (AP). The serine proteases (MASP-1/2/3, factor D, factor B), which are responsible for the activation of the cascade, are straightforward targets of inhibition, but the pattern recognition molecules (mannose-binding lectin, other collectins, and ficolins), the regulatory components (factor H, factor I, properdin), and C3 are also subjects of drug development. Recent discoveries about cross-talks between the LP and AP offer new approaches for clinical intervention. Mannan-binding lectin-associated serine proteases (MASPs) are not just responsible for LP activation, but they are also indispensable for efficient AP activation. Activated MASP-3 has recently been shown to be the enzyme that continuously supplies factor D (FD) for the AP by cleaving pro-factor D (pro-FD). In this aspect, MASP-3 emerges as a novel feasible target for the regulation of AP activity. MASP-1 was shown to be required for AP activity on various surfaces, first of all on LPS of Gram-negative bacteria.
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Affiliation(s)
- József Dobó
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - Andrea Kocsis
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - Péter Gál
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
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Verma S, Mandal A, Ansari MY, Kumar A, Abhishek K, Ghosh AK, Kumar A, Kumar V, Das S, Das P. Leishmania donovani Inhibitor of Serine Peptidases 2 Mediated Inhibition of Lectin Pathway and Upregulation of C5aR Signaling Promote Parasite Survival inside Host. Front Immunol 2018; 9:63. [PMID: 29434593 PMCID: PMC5796892 DOI: 10.3389/fimmu.2018.00063] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Accepted: 01/10/2018] [Indexed: 11/30/2022] Open
Abstract
Leishmania donovani, the causative agent of Indian visceral leishmaniasis has to face several barriers of the immune system inside the mammalian host for its survival. The complement system is one of the first barriers and consists of a well-balanced network of proteases including S1A family serine proteases (SPs). Inhibitor of serine peptidases (ISPs) is considered as inhibitor of S1A family serine peptidases and is reported to be present in trypanosomes, including Leishmania. In our previous study, we have deciphered the role of ISPs [LdISP1 and L. donovani inhibitor of serine peptidases 2 (LdISP2)] in the survival of L. donovani inside the sandfly midgut. However, the role of theses ISPs in the survival of L. donovani inside mammalian host still remains elusive. In the present study, we have deciphered the inhibitory effect of LdISPs on the host complement S1A serine peptidases, such as C1r/C1s and MASP1/MASP2. Our study suggested that although both rLdISP1 and rLdISP2 inferred strong interaction with C1complex and MBL-associated serine proteases (MASPs) but rLdISP2 showed the stronger inhibitory effect on MASP2 than rLdISP1. Moreover, we found that rLdISP2 significantly reduces the formation of C3, C5 convertase, and membrane attacking complex (MAC) by lectin pathway (LP) resulting in significant reduction in serum mediated lysis of the parasites. The role of LdISP2 on neutrophil elastase-mediated C5aR signaling was also evaluated. Notably, our results showed that infection of macrophages with ISP2-overexpressed Leishmania parasites significantly induces the expression of C5aR both at the transcript and translational level. Simultaneously, infection with ISP2KD parasites results in downregulation of host PI3K/AKT phosphorylation and increased in IL-12 production. Taken together, our findings clearly suggest that LdISP2 promotes parasite survival inside host by inhibiting MAC formation and complement-mediated lysis via LP and by upregulation of C5aR signaling.
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Affiliation(s)
- Sudha Verma
- Department of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences (ICMR), Patna, India
| | - Abhishek Mandal
- Department of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences (ICMR), Patna, India
| | - Md Yousuf Ansari
- MM College of Pharmacy, Maharishi Markandeshwar University, Ambala, India
| | - Ajay Kumar
- Department of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences (ICMR), Patna, India
| | - Kumar Abhishek
- Department of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences (ICMR), Patna, India
| | - Ayan Kumar Ghosh
- Department of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences (ICMR), Patna, India
| | - Ashish Kumar
- Department of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences (ICMR), Patna, India
| | - Vinod Kumar
- Department of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences (ICMR), Patna, India
| | - Sushmita Das
- Department of Microbiology, All India Institute of Medical Sciences, Patna, India
| | - Pradeep Das
- Department of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences (ICMR), Patna, India
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Núñez-Díaz JA, García de la Banda I, Lobo C, Moriñigo MA, Balebona MC. Transcription of immune related genes in Solea senegalensis vaccinated against Photobacterium damselae subsp. piscicida. Identification of surrogates of protection. FISH & SHELLFISH IMMUNOLOGY 2017; 66:455-465. [PMID: 28532666 DOI: 10.1016/j.fsi.2017.05.044] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 05/17/2017] [Accepted: 05/18/2017] [Indexed: 06/07/2023]
Abstract
Solea senegalensis is a flatfish with a great potential for aquaculture, but infectious diseases restrict its production, being this fish species highly susceptible to Photobacterium damselae subsp. piscicida (Phdp) infections. A better understanding of the mechanisms related to fish immune response is crucial for the development of effective approaches in disease management. In the present work, transcriptional changes of immune related genes have been evaluated in farmed S. senegalensis specimens vaccinated against Phdp by intraperitoneal injection (IP) and immersion (IM). IP fish showed higher antibody levels and increased transcription of genes encoding lysozyme C1, complement factors involved in the classical pathway and components involved in the opsonization and the limitation of free iron availability, all of them facilitating the faster elimination of the pathogen and promoting higher RPS after the infection with Phdp. The results of this study seem to support a different intensity of the specimens immune response in the head kidney. Analysis of the immune response in 15 day post-challenged fish showed up-regulation of genes involved in all stages of S. senegalensis immune response, but especially those genes encoding proteins related to the innate response such as complement, lysozyme and iron homeostasis in the head kidney. On the other hand, liver transcription was higher for genes related to inflammation, apoptosis and cell mediated cytotoxicity (CMC). Furthermore, comparison of the differential response of S. senegalensis genes in vaccinated and unvaccinated fish to Phdp infection allowed the identification of a potential biosignature, consisting in 10 genes, as a surrogate of protection and therefore, as indicator of vaccine success against fotobacteriosis after IP vaccination. These results provide important insights into the S. senegalensis protection against Phdp induced by vaccination.
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Affiliation(s)
- J A Núñez-Díaz
- Universidad de Málaga, Departamento de Microbiología, Campus de Teatinos s/n, 29071 Málaga, Spain
| | - I García de la Banda
- Spanish Institute of Oceanography, Oceanographic Center of Santander, 39080 Santander, Spain
| | - C Lobo
- Spanish Institute of Oceanography, Oceanographic Center of Santander, 39080 Santander, Spain
| | - M A Moriñigo
- Universidad de Málaga, Departamento de Microbiología, Campus de Teatinos s/n, 29071 Málaga, Spain
| | - M C Balebona
- Universidad de Málaga, Departamento de Microbiología, Campus de Teatinos s/n, 29071 Málaga, Spain.
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Foley JH, Conway EM. Cross Talk Pathways Between Coagulation and Inflammation. Circ Res 2017; 118:1392-408. [PMID: 27126649 DOI: 10.1161/circresaha.116.306853] [Citation(s) in RCA: 378] [Impact Index Per Article: 54.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2016] [Accepted: 03/21/2016] [Indexed: 02/06/2023]
Abstract
Anatomic pathology studies performed over 150 years ago revealed that excessive activation of coagulation occurs in the setting of inflammation. However, it has taken over a century since these seminal observations were made to delineate the molecular mechanisms by which these systems interact and the extent to which they participate in the pathogenesis of multiple diseases. There is, in fact, extensive cross talk between coagulation and inflammation, whereby activation of one system may amplify activation of the other, a situation that, if unopposed, may result in tissue damage or even multiorgan failure. Characterizing the common triggers and pathways are key for the strategic design of effective therapeutic interventions. In this review, we highlight some of the key molecular interactions, some of which are already showing promise as therapeutic targets for inflammatory and thrombotic disorders.
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Affiliation(s)
- Jonathan H Foley
- From the Department of Haematology, UCL Cancer Institute, University College London, London, United Kingdom (J.H.F.); Katharine Dormandy Haemophilia Centre and Thrombosis Unit, Royal Free NHS Trust, London, United Kingdom (J.H.F.); and Centre for Blood Research, Department of Medicine, University of British Columbia, Vancouver, Canada (E.M.C.)
| | - Edward M Conway
- From the Department of Haematology, UCL Cancer Institute, University College London, London, United Kingdom (J.H.F.); Katharine Dormandy Haemophilia Centre and Thrombosis Unit, Royal Free NHS Trust, London, United Kingdom (J.H.F.); and Centre for Blood Research, Department of Medicine, University of British Columbia, Vancouver, Canada (E.M.C.).
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Song Q, Zhang Z, Liu Y, Han S, Zhang X. The tag SNP rs10746463 in decay-accelerating factor is associated with the susceptibility to gastric cancer. Mol Immunol 2015; 63:473-8. [PMID: 25457880 DOI: 10.1016/j.molimm.2014.10.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Revised: 09/29/2014] [Accepted: 10/03/2014] [Indexed: 01/25/2023]
Abstract
BACKGROUND Complement activation involved in the innate immunity and adaptive immunity and further contributed to the development of tumor growth. This study aimed to investigate the association of genetic variants in complement 3 (C3) and decay-accelerating factor (DAF) genes with the risk of gastric cancer. METHODS This case-control study included 500 gastric cancer patients and 500 cancer-free controls. Based on the Chinese population data from HapMap database, we used Haploview 4.2 program to select candidate tag SNPs. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by logistic regression to evaluate the association of each genetic variant with the risk of gastric cancer. RESULTS Among 12 tag SNPs of C3, no correlation was observed between C3 genetic variants and risk of gastric cancer. For tag SNPS of DAF, logistic regression analysis revealed that the carriers with DAF rs10746463 AA genotype had a significantly increased risk for developing gastric cancer (OR = 1.46, 95% CI = 1.01–2.10) when compared with GG genotype, but those carrying with rs10746463 AG genotype didn't (OR = 1.31, 95% CI = 0.98-1.75). When stratified by smoking status, we found that the risk of gastric cancer was associated with rs10746463 GA or AA genotype carriers among smoker with OR (95% CI) of 1.64 (1.06-2.54), but not among non-smoker (OR = 1.37, 95% CI = 0.97-1.94). CONCLUSION DAF rs10746463 polymorphism effects on the risk of developing gastric cancer in Chinese population.
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Affiliation(s)
- Qinqin Song
- Institute of Molecular Genetics, College of Life Science, Hebei United University, Tangshan, China
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Kourtzelis I, Magnusson PU, Kotlabova K, Lambris JD, Chavakis T. Regulation of Instant Blood Mediated Inflammatory Reaction (IBMIR) in Pancreatic Islet Xeno-Transplantation: Points for Therapeutic Interventions. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 865:171-88. [DOI: 10.1007/978-3-319-18603-0_11] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Shahinian H, Tholen S, Schilling O. Proteomic identification of protease cleavage sites: cell-biological and biomedical applications. Expert Rev Proteomics 2014; 10:421-33. [DOI: 10.1586/14789450.2013.841547] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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20
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Bathige SDNK, Whang I, Umasuthan N, Wickramaarachchi WDN, Wan Q, Lim BS, Park MA, Lee J. Three complement component 1q genes from rock bream, Oplegnathus fasciatus: genome characterization and potential role in immune response against bacterial and viral infections. FISH & SHELLFISH IMMUNOLOGY 2013; 35:1442-1454. [PMID: 23994081 DOI: 10.1016/j.fsi.2013.08.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Revised: 07/20/2013] [Accepted: 08/14/2013] [Indexed: 06/02/2023]
Abstract
Complement component 1q (C1q) is a subcomponent of the C1 complex and the key protein that recognizes and binds to a broad range of immune and non-immune ligands to initiate the classical complement pathway. In the present study, we identified and characterized three novel C1q family members from rock bream, Oplegnathus fasciatus. The full-length cDNAs of C1q A-like (RbC1qAL), C1q B-like (RbC1qBL), and C1q C-like (RbC1qCL) consist of 780, 720 and 726 bp of nucleotide sequence encoding polypeptides of 260, 240 and 242 amino acids, respectively. All three RbC1qs possess a leading signal peptide and collagen-like region(s) (CLRs) in the N-terminus, and a C1q domain at the C-terminus. The C1q characteristic Gly-X-Y repeats are present in all three RbC1qs, while the CLR-associated sequence that enhances phagocytic activity is present in RbC1qAL ((49)GEKGEP(54)) and RbC1qCL ((70)GEKGEP(75)). Moreover, the coding region was distributed across six exons in RbCqAL and RbC1qCL, but only five exons in RbC1qBL. Phylogenetic analysis revealed that the three RbC1qs tightly cluster with the fish clade. All three RbC1qs are most highly expressed in the spleen and liver, as indicated by qPCR tissue profiling. In addition, all three are transcriptionally responsive to immune challenge, with liver expression being significantly up-regulated in the early phase of infection with intact, live bacteria (Edwardsiella tarda and Streptococcus iniae) and virus (rock bream iridovirus) and in the late phase of exposure to purified endotoxin (lipopolysaccharide). These data collectively suggest that the RbC1qs may play defense roles as an innate immune response to protect the rock bream from bacterial and viral infections.
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Affiliation(s)
- S D N K Bathige
- Department of Marine Life Sciences, School of Marine Biomedical Sciences, Jeju National University, Jeju Self-Governing Province 690-756, Republic of Korea
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P-I snake venom metalloproteinase is able to activate the complement system by direct cleavage of central components of the cascade. PLoS Negl Trop Dis 2013; 7:e2519. [PMID: 24205428 PMCID: PMC3814341 DOI: 10.1371/journal.pntd.0002519] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2013] [Accepted: 09/21/2013] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Snake Venom Metalloproteinases (SVMPs) are amongst the key enzymes that contribute to the high toxicity of snake venom. We have recently shown that snake venoms from the Bothrops genus activate the Complement system (C) by promoting direct cleavage of C-components and generating anaphylatoxins, thereby contributing to the pathology and spread of the venom. The aim of the present study was to isolate and characterize the C-activating protease from Bothrops pirajai venom. RESULTS Using two gel-filtration chromatography steps, a metalloproteinase of 23 kDa that activates Complement was isolated from Bothrops pirajai venom. The mass spectrometric identification of this protein, named here as C-SVMP, revealed peptides that matched sequences from the P-I class of SVMPs. C-SVMP activated the alternative, classical and lectin C-pathways by cleaving the α-chain of C3, C4 and C5, thereby generating anaphylatoxins C3a, C4a and C5a. In vivo, C-SVMP induced consumption of murine complement components, most likely by activation of the pathways and/or by direct cleavage of C3, leading to a reduction of serum lytic activity. CONCLUSION We show here that a P-I metalloproteinase from Bothrops pirajai snake venom activated the Complement system by direct cleavage of the central C-components, i.e., C3, C4 and C5, thereby generating biologically active fragments, such as anaphylatoxins, and by cleaving the C1-Inhibitor, which may affect Complement activation control. These results suggest that direct complement activation by SVMPs may play a role in the progression of symptoms that follow envenomation.
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Degn SE, Jensen L, Olszowski T, Jensenius JC, Thiel S. Co-complexes of MASP-1 and MASP-2 associated with the soluble pattern-recognition molecules drive lectin pathway activation in a manner inhibitable by MAp44. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2013; 191:1334-45. [PMID: 23785123 DOI: 10.4049/jimmunol.1300780] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The lectin pathway of complement is an integral component of innate immunity. It is activated upon binding of mannan-binding lectin (MBL) or ficolins (H-, L-, and M-ficolin) to suitable ligand patterns on microorganisms. MBL and ficolins are polydisperse homo-oligomeric molecules, found in complexes with MBL-associated serine proteases (MASP-1, -2, and -3) and MBL-associated proteins (MAp19 and MAp44). This scenario is far more complex than the well-defined activation complex of the classical pathway, C1qC1r(2)C1s(2), and the composition of the activating complexes of the lectin pathway is ill defined. We and other investigators recently demonstrated that both MASP-1 and MASP-2 are crucial to lectin pathway activation. MASP-1 transactivates MASP-2 and, although MASP-1 also cleaves C2, MASP-2 cleaves both C4 and C2, allowing formation of the C3 convertase, C4bC2a. Juxtaposition of MASP-1 and MASP-2 during activation must be required for transactivation. We previously presented a possible scenario, which parallels that of the classical pathway, in which MASP-1 and MASP-2 are found together in the same MBL or ficolin complex. In this study, we demonstrate that, although MASPs do not directly form heterodimers, the addition of MBL or ficolins allows the formation of MASP-1-MASP-2 co-complexes. We find that such co-complexes have a functional role in activating complement and are present in serum at varying levels, impacting on the degree of complement activation. This raises the novel possibility that MAp44 may inhibit complement, not simply by brute force displacement of MASP-2 from MBL or ficolins, but by disruption of co-complexes, hence impairing transactivation. We present support for this contention.
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Affiliation(s)
- Søren E Degn
- Department of Biomedicine, Aarhus University, 8000 Aarhus C, Denmark.
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23
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Degn SE, Jensenius JC, Thiel S. Response to comment on "Mannan-binding lectin-associated serine protease (MASP)-1 is crucial for lectin pathway activation in human serum, whereas neither MASP-1 nor MASP-3 is required for alternative pathway function". THE JOURNAL OF IMMUNOLOGY 2013; 190:2477-8. [PMID: 23509401 DOI: 10.4049/jimmunol.1390003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Megyeri M, Harmat V, Major B, Végh Á, Balczer J, Héja D, Szilágyi K, Datz D, Pál G, Závodszky P, Gál P, Dobó J. Quantitative characterization of the activation steps of mannan-binding lectin (MBL)-associated serine proteases (MASPs) points to the central role of MASP-1 in the initiation of the complement lectin pathway. J Biol Chem 2013; 288:8922-34. [PMID: 23386610 DOI: 10.1074/jbc.m112.446500] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Mannan-binding lectin (MBL)-associated serine proteases, MASP-1 and MASP-2, have been thought to autoactivate when MBL/ficolin·MASP complexes bind to pathogens triggering the complement lectin pathway. Autoactivation of MASPs occurs in two steps: 1) zymogen autoactivation, when one proenzyme cleaves another proenzyme molecule of the same protease, and 2) autocatalytic activation, when the activated protease cleaves its own zymogen. Using recombinant catalytic fragments, we demonstrated that a stable proenzyme MASP-1 variant (R448Q) cleaved the inactive, catalytic site Ser-to-Ala variant (S646A). The autoactivation steps of MASP-1 were separately quantified using these mutants and the wild type enzyme. Analogous mutants were made for MASP-2, and rate constants of the autoactivation steps as well as the possible cross-activation steps between MASP-1 and MASP-2 were determined. Based on the rate constants, a kinetic model of lectin pathway activation was outlined. The zymogen autoactivation rate of MASP-1 is ∼3000-fold higher, and the autocatalytic activation of MASP-1 is about 140-fold faster than those of MASP-2. Moreover, both activated and proenzyme MASP-1 can effectively cleave proenzyme MASP-2. MASP-3, which does not autoactivate, is also cleaved by MASP-1 quite efficiently. The structure of the catalytic region of proenzyme MASP-1 R448Q was solved at 2.5 Å. Proenzyme MASP-1 R448Q readily cleaves synthetic substrates, and it is inhibited by a specific canonical inhibitor developed against active MASP-1, indicating that zymogen MASP-1 fluctuates between an inactive and an active-like conformation. The determined structure provides a feasible explanation for this phenomenon. In summary, autoactivation of MASP-1 is crucial for the activation of MBL/ficolin·MASP complexes, and in the proenzymic phase zymogen MASP-1 controls the process.
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Affiliation(s)
- Márton Megyeri
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, 29 Karolina Street, H-1113 Budapest, Hungary
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Carroll S, Georgiou G. Antibody-mediates inhibition of human C1s and the classical complement pathway. Immunobiology 2013; 218:1041-8. [PMID: 23434433 DOI: 10.1016/j.imbio.2013.01.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Revised: 01/02/2013] [Accepted: 01/02/2013] [Indexed: 01/19/2023]
Abstract
Disregulation of complement activation plays a critical role in numerous inflammatory diseases and therefore, inhibition of the complement pathway is of great therapeutic interest. In the classical complement pathway, immune complexes formed by IgM, IgG1, IgG2 and IgG3 antibodies result in the activation of the C1s protease that in turn cleaves C4 and then C4-bound-C2 yielding the proteolytic fragments C4b and C2a which associate to form a C3 convertase enzyme. We report here the engineering of a potent human antibody inhibitor of C1s protease activity. Phage panning of a very large synthetic (F(AB)) antibody fragment library using a truncated version of C1s, comprising the second CCP domain and serine protease domain (CCP₂-SP) and expressed in insect cells, resulted in the isolation of a F(AB) that inhibited the catalytic activity of C1s. An affinity matured variant of the F(AB) format antibody displaying subnanomolar K(D) for C1s was shown to exhibit >80% inhibition of C2 processing at a 5:1 antibody:C1s molar ratio. We show that this engineered antibody, D.35, displays potent inhibition of complement deposition and lysis of Ramos cells by the anti-CD20 therapeutic antibody rituximab relative to the approved, but less-specific, human plasma-derived C1-inhibitor (CINRYZE). C1s inhibitory antibodies should be useful for delineating the role of the classical pathway in disease models and may hold promise as therapeutic agents.
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Affiliation(s)
- Sean Carroll
- Department of Chemical Engineering, University of Texas at Austin, Austin, TX, USA
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26
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Initiation and regulation of complement during hemolytic transfusion reactions. Clin Dev Immunol 2012; 2012:307093. [PMID: 23118779 PMCID: PMC3479954 DOI: 10.1155/2012/307093] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2012] [Accepted: 09/07/2012] [Indexed: 11/19/2022]
Abstract
Hemolytic transfusion reactions represent one of the most common causes of transfusion-related mortality. Although many factors influence hemolytic transfusion reactions, complement activation represents one of the most common features associated with fatality. In this paper we will focus on the role of complement in initiating and regulating hemolytic transfusion reactions and will discuss potential strategies aimed at mitigating or favorably modulating complement during incompatible red blood cell transfusions.
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Hess K, Ajjan R, Phoenix F, Dobó J, Gál P, Schroeder V. Effects of MASP-1 of the complement system on activation of coagulation factors and plasma clot formation. PLoS One 2012; 7:e35690. [PMID: 22536427 PMCID: PMC3335018 DOI: 10.1371/journal.pone.0035690] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Accepted: 03/22/2012] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Numerous interactions between the coagulation and complement systems have been shown. Recently, links between coagulation and mannan-binding lectin-associated serine protease-1 (MASP-1) of the complement lectin pathway have been proposed. Our aim was to investigate MASP-1 activation of factor XIII (FXIII), fibrinogen, prothrombin, and thrombin-activatable fibrinolysis inhibitor (TAFI) in plasma-based systems, and to analyse effects of MASP-1 on plasma clot formation, structure and lysis. METHODOLOGY/PRINCIPAL FINDINGS We used a FXIII incorporation assay and specific assays to measure the activation products prothrombin fragment F1+2, fibrinopeptide A (FPA), and activated TAFI (TAFIa). Clot formation and lysis were assessed by turbidimetric assay. Clot structure was studied by scanning electron microscopy. MASP-1 activated FXIII and, contrary to thrombin, induced FXIII activity faster in the Val34 than the Leu34 variant. MASP-1-dependent generation of F1+2, FPA and TAFIa showed a dose-dependent response in normal citrated plasma (NCP), albeit MASP-1 was much less efficient than FXa or thrombin. MASP-1 activation of prothrombin and TAFI cleavage were confirmed in purified systems. No FPA generation was observed in prothrombin-depleted plasma. MASP-1 induced clot formation in NCP, affected clot structure, and prolonged clot lysis. CONCLUSIONS/SIGNIFICANCE We show that MASP-1 interacts with plasma clot formation on different levels and influences fibrin structure. Although MASP-1-induced fibrin formation is thrombin-dependent, MASP-1 directly activates prothrombin, FXIII and TAFI. We suggest that MASP-1, in concerted action with other complement and coagulation proteins, may play a role in fibrin clot formation.
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Affiliation(s)
- Katharina Hess
- Department of Internal Medicine, Cardiology, University Hospital Aachen, Aachen, Germany
- Division of Cardiovascular and Diabetes Research, The LIGHT Laboratories, Multidisciplinary Cardiovascular Research Center, University of Leeds, Leeds, United Kingdom
| | - Ramzi Ajjan
- Division of Cardiovascular and Diabetes Research, The LIGHT Laboratories, Multidisciplinary Cardiovascular Research Center, University of Leeds, Leeds, United Kingdom
| | - Fladia Phoenix
- Division of Cardiovascular and Diabetes Research, The LIGHT Laboratories, Multidisciplinary Cardiovascular Research Center, University of Leeds, Leeds, United Kingdom
| | - József Dobó
- Institute of Enzymology, Biological Research Center, Hungarian Academy of Sciences, Budapest, Hungary
| | - Péter Gál
- Institute of Enzymology, Biological Research Center, Hungarian Academy of Sciences, Budapest, Hungary
| | - Verena Schroeder
- Division of Cardiovascular and Diabetes Research, The LIGHT Laboratories, Multidisciplinary Cardiovascular Research Center, University of Leeds, Leeds, United Kingdom
- University Clinic of Hematology and Central Hematology Laboratory, Hemostasis Research Laboratory, University Hospital and University of Bern, Bern, Switzerland
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Rao XJ, Xu XX, Yu XQ. Functional analysis of two lebocin-related proteins from Manduca sexta. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2012; 42:231-9. [PMID: 22198332 PMCID: PMC3288250 DOI: 10.1016/j.ibmb.2011.12.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2011] [Revised: 12/06/2011] [Accepted: 12/08/2011] [Indexed: 05/03/2023]
Abstract
Insects produce a group of antimicrobial peptides (AMPs) in response to microbial infections. Most AMPs are synthesized as inactive precursors/pro-proteins and require proteolytic processing to generate small active peptides. Here we report identification and functional analysis of two lebocin-related proteins (Leb-B and Leb-C) from the tobacco hornworm, Manduca sexta. The mRNA levels of Leb-B and Leb-C increased significantly in larval fat body and hemocytes after injection of Escherichia coli, Micrococcus luteus and Saccharomyces cerevisiae. Western blotting using rabbit polyclonal antibody to Leb-B showed accumulation of large protein(s) and small peptide(s) in larval hemolymph after microbial injection. This result and the presence of RXXR motifs in the deduced amino acid sequences led to our postulation that Leb-B/C may be inactive precursors that are processed in larval hemolymph to generate short active peptides. To test this hypothesis, we expressed and purified full-length and various fragments of Leb-B and Leb-C as thioredoxin (TRX) fusion proteins. We found that fusion proteins could be cleaved by induced larval plasma, and the cleavage sites were determined by protein sequencing. Antibacterial activity of peptide fragments was also verified using synthetic peptides, and active M. sexta lebocin peptides were located at the N-termini of Leb-B/C, which are different from Bombyx mori lebocins 1-4 that are located close to the C-termini. In addition, we found that synthetic Leb-B(22-48) peptide not only had higher antibacterial activity but also caused agglutination of E. coli cells. Our results provide valuable information for studying processing of lebocin precursors in lepidopteran insects.
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Affiliation(s)
| | | | - Xiao-Qiang Yu
- Send correspondence to: Xiao-Qiang Yu, PhD, Division of Cell Biology and Biophysics, School of Biological Sciences, University of Missouri-Kansas City, 5007 Rockhill Road, Kansas City, MO 64110, Telephone: (816)-235-6379, Fax: (816)-235-1503,
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Tarr AW, Urbanowicz RA, Ball JK. The role of humoral innate immunity in hepatitis C virus infection. Viruses 2012; 4:1-27. [PMID: 22355450 PMCID: PMC3280516 DOI: 10.3390/v4010001] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Revised: 12/21/2011] [Accepted: 12/23/2011] [Indexed: 12/19/2022] Open
Abstract
Infection with Hepatitis C Virus (HCV) causes chronic disease in approximately 80% of cases, resulting in chronic inflammation and cirrhosis. Current treatments are not completely effective, and a vaccine has yet to be developed. Spontaneous resolution of infection is associated with effective host adaptive immunity to HCV, including production of both HCV-specific T cells and neutralizing antibodies. However, the supporting role of soluble innate factors in protection against HCV is less well understood. The innate immune system provides an immediate line of defense against infections, triggering inflammation and playing a critical role in activating adaptive immunity. Innate immunity comprises both cellular and humoral components, the humoral arm consisting of pattern recognition molecules such as complement C1q, collectins and ficolins. These molecules activate the complement cascade, neutralize pathogens, and recruit antigen presenting cells. Here we review the current understanding of anti-viral components of the humoral innate immune system that play a similar role to antibodies, describing their role in immunity to HCV and their potential contribution to HCV pathogenesis.
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Affiliation(s)
- Alexander W. Tarr
- Biomedical Research Unit in Gastroenterology, School of Molecular Medical Sciences, Faculty of Medicine and Health Sciences, University of Nottingham, Nottingham, NG7 2UH, UK; (R.A.U.); (J.K.B.)
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Kocsis A, Kékesi KA, Szász R, Végh BM, Balczer J, Dobó J, Závodszky P, Gál P, Pál G. Selective inhibition of the lectin pathway of complement with phage display selected peptides against mannose-binding lectin-associated serine protease (MASP)-1 and -2: significant contribution of MASP-1 to lectin pathway activation. THE JOURNAL OF IMMUNOLOGY 2010; 185:4169-78. [PMID: 20817870 DOI: 10.4049/jimmunol.1001819] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The complement system, an essential part of the innate immune system, can be activated through three distinct routes: the classical, the alternative, and the lectin pathways. The contribution of individual activation pathways to different biological processes can be assessed by using pathway-selective inhibitors. In this paper, we report lectin pathway-specific short peptide inhibitors developed by phage display against mannose-binding lectin-associated serine proteases (MASPs), MASP-1 and MASP-2. On the basis of the selected peptide sequences, two 14-mer peptides, designated as sunflower MASP inhibitor (SFMI)-1 and SFMI-2, were produced and characterized. SFMI-1 inhibits both MASP-1 and MASP-2 with a K(I) of 65 and 1030 nM, respectively, whereas SFMI-2 inhibits only MASP-2 with a K(I) of 180 nM. Both peptides block the lectin pathway activation completely while leaving the classical and the alternative routes intact and fully functional, demonstrating that of all complement proteases only MASP-1 and/or MASP-2 are inhibited by these peptides. In a C4 deposition inhibitor assay using preactivated MASP-2, SFMI-2 is 10-fold more effective than SFMI-1 in accordance with the fact that SFMI-2 is a more potent inhibitor of MASP-2. Surprisingly, however, out of the two peptides, SFMI-1 is much more effective in preventing C3 and C4 deposition when normal human serum containing zymogen MASPs is used. This suggests that MASP-1 has a crucial role in the initiation steps of lectin pathway activation most probably by activating MASP-2. Because the lectin pathway has been implicated in several life-threatening pathological states, these inhibitors should be considered as lead compounds toward developing lectin pathway blocking therapeutics.
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Affiliation(s)
- Andrea Kocsis
- Institute of Enzymology, Biological Research Center, Hungarian Academy of Sciences, Budapest, Hungary
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31
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Degn SE, Jensen L, Gál P, Dobó J, Holmvad SH, Jensenius JC, Thiel S. Biological variations of MASP-3 and MAp44, two splice products of the MASP1 gene involved in regulation of the complement system. J Immunol Methods 2010; 361:37-50. [PMID: 20673767 DOI: 10.1016/j.jim.2010.07.006] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2010] [Revised: 07/19/2010] [Accepted: 07/20/2010] [Indexed: 11/24/2022]
Abstract
The lectin pathway of complement is part of the innate immune system. The complement-activating pattern-recognition molecules (for which we suggest the abbreviation CAPREMs) mannan-binding lectin (MBL) and the three ficolins (H-, L- and M-ficolin) circulate in complexes with MBL-associated serine proteases (MASP-1, -2 and -3) and two additional proteins (MAp19 and MAp44, also termed sMAP and MAP-1, respectively). When MBL or ficolins recognize a microorganism or altered self components, activation of the MASPs ensues, leading to the activation of the complement system. MASP-1, MASP-3 and MAp44 are all three encoded by the MASP1 gene. MASP-1 and -3 share five domains (constituting the so-called A-chain), but have unique protease domains (B-chains). MAp44 shares the first four domains with MASP-1 and MASP-3, followed by 17 unique C-terminal amino acid residues. Thus, assays for the protease domain of MASP-3 and for the 17 C-terminal amino acids of MAp44 are required to measure these proteins specifically and here we present such assays for MASP-3 and MAp44. MASP-3 was captured with a monoclonal antibody (5F5) reacting with a common domain of the three proteins (CCP1) and the assay was developed with a monoclonal antibody (38.12.3) specific for the C-terminal part of the MASP-3 protease domain. MAp44 was captured with a monoclonal antibody (2D5) reacting with the C-terminus of MAp44 followed by assay development with a monoclonal anti-CCP1 antibody (4H2). Using Superose 6 gel permeation chromatography of serum, MASP-3 and MAp44 were found in complexes, which eluted in positions corresponding to 600-800 kDa and 500-700 kDa, respectively. The level of MASP-3 in donor sera (N=200) was log-normally distributed with a median value of 5.0 μg/ml (range: 1.8-10.6 μg/ml), and the corresponding value for MAp44, also log-normally distributed, was 1.7 μg/ml (range: 0.8-3.2 μg/ml). For MASP-3, the inter-assay coefficients of variation of low, intermediate and high level internal controls were 4.9%, 6.9% and 3.9% (N=12). For MAp44, the corresponding inter-assay CVs were 7.6%, 6.2%, and 7.0% (N=12). MASP-3 levels were low at birth and reached adult levels within the first 6 months, whereas MAp44 levels fell slightly during the first 6 months. Concomitant with the acute phase response in patients undergoing major surgery, levels of both proteins fell slightly over 1-2 days, but whereas MASP-3 recovered to baseline values over another 2 days, MAp44 only reached baseline values at around day 30. Thus, neither of the two proteins behaves as a classical acute phase protein.
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Affiliation(s)
- Søren E Degn
- Department of Medical Microbiology and Immunology, Aarhus University, Wilhelm Meyers Allé 4, 8000 Arhus C, Denmark.
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Brier S, Pflieger D, Le Mignon M, Bally I, Gaboriaud C, Arlaud GJ, Daniel R. Mapping surface accessibility of the C1r/C1s tetramer by chemical modification and mass spectrometry provides new insights into assembly of the human C1 complex. J Biol Chem 2010; 285:32251-63. [PMID: 20592021 DOI: 10.1074/jbc.m110.149112] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
C1, the complex that triggers the classic pathway of complement, is a 790-kDa assembly resulting from association of a recognition protein C1q with a Ca(2+)-dependent tetramer comprising two copies of the proteases C1r and C1s. Early structural investigations have shown that the extended C1s-C1r-C1r-C1s tetramer folds into a compact conformation in C1. Recent site-directed mutagenesis studies have identified the C1q-binding sites in C1r and C1s and led to a three-dimensional model of the C1 complex (Bally, I., Rossi, V., Lunardi, T., Thielens, N. M., Gaboriaud, C., and Arlaud, G. J. (2009) J. Biol. Chem. 284, 19340-19348). In this study, we have used a mass spectrometry-based strategy involving a label-free semi-quantitative analysis of protein samples to gain new structural insights into C1 assembly. Using a stable chemical modification, we have compared the accessibility of the lysine residues in the isolated tetramer and in C1. The labeling data account for 51 of the 73 lysine residues of C1r and C1s. They strongly support the hypothesis that both C1s CUB(1)-EGF-CUB(2) interaction domains, which are distant in the free tetramer, associate with each other in the C1 complex. This analysis also provides the first experimental evidence that, in the proenzyme form of C1, the C1s serine protease domain is partly positioned inside the C1q cone and yields precise information about its orientation in the complex. These results provide further structural insights into the architecture of the C1 complex, allowing significant improvement of our current C1 model.
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Affiliation(s)
- Sébastien Brier
- CNRS, UMR 8587, Université d'Evry-Val-d'Essonne, Laboratoire Analyse et Modélisation pour la Biologie et l'Environnement, Boulevard François Mitterrand, 91025 Evry, France.
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Abstract
The complement system plays a crucial role in the innate defense against common pathogens. Activation of complement leads to robust and efficient proteolytic cascades, which terminate in opsonization and lysis of the pathogen as well as in the generation of the classical inflammatory response through the production of potent proinflammatory molecules. More recently, however, the role of complement in the immune response has been expanded due to observations that link complement activation to adaptive immune responses. It is now appreciated that complement is a functional bridge between innate and adaptive immune responses that allows an integrated host defense to pathogenic challenges. As such, a study of its functions allows insight into the molecular underpinnings of host-pathogen interactions as well as the organization and orchestration of the host immune response. This review attempts to summarize the roles that complement plays in both innate and adaptive immune responses and the consequences of these interactions on host defense.
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Qu H, Ricklin D, Lambris JD. Recent developments in low molecular weight complement inhibitors. Mol Immunol 2009; 47:185-95. [PMID: 19800693 DOI: 10.1016/j.molimm.2009.08.032] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2009] [Accepted: 08/28/2009] [Indexed: 11/18/2022]
Abstract
As a key part of the innate immune system, complement plays an important role not only in defending against invading pathogens but also in many other biological processes. Inappropriate or excessive activation of complement has been linked to many autoimmune, inflammatory, and neurodegenerative diseases, as well as ischemia-reperfusion injury and cancer. A wide array of low molecular weight complement inhibitors has been developed to target various components of the complement cascade. Their efficacy has been demonstrated in numerous in vitro and in vivo experiments. Though none of these inhibitors has reached the market so far, some of them have entered clinical trials and displayed promising results. This review provides a brief overview of the currently developed low molecular weight complement inhibitors, including short peptides and synthetic small molecules, with an emphasis on those targeting components C1 and C3, and the anaphylatoxin receptors.
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Affiliation(s)
- Hongchang Qu
- Department of Pathology and Laboratory Medicine, School of Medicine, University of Pennsylvania, 401 Stellar Chance, 422 Curie Blvd., Philadelphia, PA 19104, USA
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35
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Abstract
The complement system is important for cellular integrity and tissue homeostasis. Complement activation mediates the removal of microorganisms and the clearance of modified self cells, such as apoptotic cells. Complement regulators control the spontaneously activated complement cascade and any disturbances in this delicate balance can result in damage to tissues and in autoimmune disease. Therefore, insights into the mechanisms of complement regulation are crucial for understanding disease pathology and for enabling the development of diagnostic tools and therapies for complement-associated diseases.
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Affiliation(s)
- Peter F Zipfel
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Beutenbergstrasse 11a, Jena, Germany.
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Than NG, Romero R, Erez O, Kusanovic JP, Tarca AL, Edwin SS, Kim JS, Hassan SS, Espinoza J, Mittal P, Mazaki-Tovi S, Friel L, Gotsch F, Vaisbuch E, Camacho N, Papp Z. A role for mannose-binding lectin, a component of the innate immune system in pre-eclampsia. Am J Reprod Immunol 2009; 60:333-45. [PMID: 18727690 DOI: 10.1111/j.1600-0897.2008.00631.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
PROBLEM Mannose-binding lectin (MBL) is a pattern-recognition receptor that activates complement and modulates inflammation. Homozygosity for the most common allele of the MBL2 gene that is associated with high MBL serum concentrations is more prevalent among patients with pre-eclampsia. The objective of this study was to determine maternal plasma MBL concentrations in normal pregnant women and patients with pre-eclampsia. METHOD OF STUDY This cross-sectional study included normal pregnant women (n = 187) and patients with pre-eclampsia (n = 99). Maternal plasma MBL concentrations were determined by ELISA. RESULTS Women with pre-eclampsia had a higher median maternal plasma MBL concentration than normal pregnant women. MBL concentration distribution curves were three-modal, the subintervals in normal pregnancy were low (< 143.7), intermediate (143.7-1898.9) and high (> 1898.9 ng/mL). The proportion of normal pregnant women was larger in the low subinterval, while the proportion of patients with preeclampsia was larger in the high subinterval (P = 0.02). Normal pregnant women in the high subinterval had a larger rate of placental underperfusion than those in the low and intermediate subintervals (P = 0.02). CONCLUSIONS The median maternal plasma MBL concentration is elevated in patients with pre-eclampsia and a larger proportion of these patients are in the high subinterval than normal pregnant women, suggesting that this component of the innate immune system is involved in the mechanisms of disease in pre-eclampsia.
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Affiliation(s)
- Nandor Gabor Than
- Perinatology Research Branch, NICHD/NIH/DHHS, Wayne State University/Hutzel Women's Hospital, 3990 John R, Box 4, Detroit, MI 48201, USA.
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Megyeri M, Makó V, Beinrohr L, Doleschall Z, Prohászka Z, Cervenak L, Závodszky P, Gál P. Complement protease MASP-1 activates human endothelial cells: PAR4 activation is a link between complement and endothelial function. THE JOURNAL OF IMMUNOLOGY 2009; 183:3409-16. [PMID: 19667088 DOI: 10.4049/jimmunol.0900879] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Activation of the complement system can induce and enhance inflammatory reaction. Mannose-binding lectin-associated serine protease-1 (MASP-1) is an abundant protease of the complement lectin pathway; however, its physiological function is unclear. In this study, we demonstrate for the first time that MASP-1 is able to activate Ca(2+) signaling, NF-kappaB, and p38 MAPK pathways in cultured HUVECs. Activation was initiated by MASP-1 only; the related protease, MASP-2, had no such effect. The phenomenon was dependent on the proteolytic activity of MASP-1, suggesting modulation of endothelial cell function through a protease-activated receptor (PAR). Using synthetic peptide substrates representing the protease-sensitive regions of PARs, we were able to demonstrate that PAR4 is a target of MASP-1. The presence of functionally active PAR4 in HUVECs was demonstrated using PAR4 agonist peptide and mRNA quantification. Finally, we showed that the amount of membrane-bound intact PAR4 decreases after MASP-1 treatment. All of these results provide a novel link between the regulation of endothelial cell function and complement system activation, and they suggest that MASP-1-induced PAR4 activation could contribute to the development of the inflammatory reaction.
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Affiliation(s)
- Márton Megyeri
- Institute of Enzymology, Biological Research Center, Hungarian Academy of Sciences, Budapest, Hungary
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Dobó J, Harmat V, Beinrohr L, Sebestyén E, Závodszky P, Gál P. MASP-1, a promiscuous complement protease: structure of its catalytic region reveals the basis of its broad specificity. THE JOURNAL OF IMMUNOLOGY 2009; 183:1207-14. [PMID: 19564340 DOI: 10.4049/jimmunol.0901141] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Mannose-binding lectin (MBL)-associated serine protease (MASP)-1 is an abundant component of the lectin pathway of complement. The related enzyme, MASP-2 is capable of activating the complement cascade alone. Though the concentration of MASP-1 far exceeds that of MASP-2, only a supporting role of MASP-1 has been identified regarding lectin pathway activation. Several non-complement substrates, like fibrinogen and factor XIII, have also been reported. MASP-1 belongs to the C1r/C1s/MASP family of modular serine proteases; however, its serine protease domain is evolutionary different. We have determined the crystal structure of the catalytic region of active MASP-1 and refined it to 2.55 A resolution. Unusual features of the structure are an internal salt bridge (similar to one in factor D) between the S1 Asp189 and Arg224, and a very long 60-loop. The functional and evolutionary differences between MASP-1 and the other members of the C1r/C1s/MASP family are reflected in the crystal structure. Structural comparison of the protease domains revealed that the substrate binding groove of MASP-1 is wide and resembles that of trypsin rather than early complement proteases explaining its relaxed specificity. Also, MASP-1's multifunctional behavior as both a complement and a coagulation enzyme is in accordance with our observation that antithrombin in the presence of heparin is a more potent inhibitor of MASP-1 than C1 inhibitor. Overall, MASP-1 behaves as a promiscuous protease. The structure shows that its substrate binding groove is accessible; however, its reactivity could be modulated by an unusually large 60-loop and an internal salt bridge involving the S1 Asp.
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Affiliation(s)
- József Dobó
- Institute of Enzymology, Biological Research Center, Hungarian Academy of Sciences, Budapest, Hungary.
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Gál P, Dobó J, Závodszky P, Sim RBM. Early complement proteases: C1r, C1s and MASPs. A structural insight into activation and functions. Mol Immunol 2009; 46:2745-52. [PMID: 19477526 DOI: 10.1016/j.molimm.2009.04.026] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2009] [Accepted: 04/28/2009] [Indexed: 10/20/2022]
Abstract
C1r, C1s and the mannose-binding lectin-associated serine proteases (MASPs) are responsible for the initiation of the classical- and lectin pathway activation of the complement system. These enzymes do not act alone, but form supramolecular complexes with pattern recognition molecules such as C1q, MBL, and ficolins. They share the same domain organization but have different substrate specificities and fulfill different physiological functions. In the recent years the rapid progress of structural biology facilitated the understanding of the molecular mechanism of complement activation at atomic level. In this review we summarize our current knowledge about the structure and function of the early complement proteases, delineate the latest models of the multimolecular complexes and present the functional consequences inferred from the structural studies. We also discuss some open questions and debated issues that need to be resolved in the future.
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Affiliation(s)
- Péter Gál
- Institute of Enzymology, Biological Research Center, Hungarian Academy of Sciences, Budapest, Hungary.
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Mannan-binding lectin-associated serine protease-2 (MASP-2) in a large cohort of neonates and its clinical associations. Mol Immunol 2009; 46:1696-701. [DOI: 10.1016/j.molimm.2009.02.022] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2008] [Revised: 01/12/2009] [Accepted: 02/13/2009] [Indexed: 11/19/2022]
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Dobó J, Harmat V, Sebestyén E, Beinrohr L, Závodszky P, Gál P. Purification, crystallization and preliminary X-ray analysis of human mannose-binding lectin-associated serine protease-1 (MASP-1) catalytic region. Acta Crystallogr Sect F Struct Biol Cryst Commun 2008; 64:781-4. [PMID: 18765903 PMCID: PMC2531277 DOI: 10.1107/s174430910802294x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2008] [Accepted: 07/21/2008] [Indexed: 11/10/2022]
Abstract
MASP-1, a multidomain serine protease, is a component of the lectin pathway of complement. Its precise function is unknown, although it seems to enhance the complement-activating capacity of MASP-2, a related enzyme. MASP-1 has also been implicated as playing a role in blood coagulation. It is mostly found associated with mannose-binding lectin (MBL) and ficolins. Early attempts to crystallize MASP-1 failed because of the inhomogeneity of the purified material. MASP-1 was shown by acidic nondenaturing PAGE to be composed of differently charged species, which are most likely to be the products of deamidation occurring during the refolding procedure. Sequential cation-exchange and anion-exchange chromatography resulted in a homogeneous material, which was successfully crystallized. The best crystal diffracted to 2.55 A resolution and belonged to space group P2(1)2(1)2(1), with unit-cell parameters a = 68.4, b = 70.4, c = 121.4 A. The crystal structure of MASP-1 may help in understanding the function of this mysterious serine protease.
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Affiliation(s)
- József Dobó
- Institute of Enzymology, Biological Research Center, Hungarian Academy of Sciences, Karolina út 29, H-1113 Budapest, Hungary.
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Rawal N, Rajagopalan R, Salvi VP. Activation of complement component C5: comparison of C5 convertases of the lectin pathway and the classical pathway of complement. J Biol Chem 2008; 283:7853-63. [PMID: 18204047 DOI: 10.1074/jbc.m707591200] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Although the initiating complex of lectin pathway (called M1 in this study) generates C3/C5 convertases similar to those assembled by the initiating complex (C1) of the classical pathway, activation of complement component C5 via the lectin pathway has not been examined. In the present study kinetic analysis of lectin pathway C3/C5 convertases assembled on two surfaces (zymosan and sheep erythrocytes coated with mannan (E(Man))) revealed that the convertases (ZymM1,C4b,C2a and E(Man)M1,C4b,C2a) exhibited a similar but weak affinity for the substrate, C5 indicated by a high K(m) (2.73-6.88 microm). Very high affinity C5 convertases were generated when the low affinity C3/C5 convertases were allowed to deposit C3b by cleaving native C3. These C3b-containing convertases exhibited K(m) (0.0086-0.0075 microm) well below the normal concentration of C5 in blood (0.37 microm). Although kinetic parameters, K(m) and k(cat), of the lectin pathway C3/C5 convertases were similar to those reported for classical pathway C3/C5 convertases, studies on the ability of C4b to bind C2 indicated that every C4b deposited on zymosan or E(Man) was capable of forming a convertase. These findings differ from those reported for the classical pathway C3/C5 convertase, where only one of four C4b molecules deposited formed a convertase. The potential for four times more amplification via the lectin pathway than the classical pathway in the generation of C3/C5 convertases and production of pro-inflammatory products, such as C3a, C4a, and C5a, implies that activation of complement via the lectin pathway might be a more prominent contributor to the pathology of inflammatory reactions.
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Affiliation(s)
- Nenoo Rawal
- Department of Biochemistry, University of Texas Health Science Center, Tyler, Texas 75708, USA.
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Revisiting the mechanism of the autoactivation of the complement protease C1r in the C1 complex: structure of the active catalytic region of C1r. Mol Immunol 2007; 45:1752-60. [PMID: 17996945 DOI: 10.1016/j.molimm.2007.09.031] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2007] [Revised: 09/25/2007] [Accepted: 09/27/2007] [Indexed: 11/20/2022]
Abstract
C1r is a modular serine protease which is the autoactivating component of the C1 complex of the classical pathway of the complement system. We have determined the first crystal structure of the entire active catalytic region of human C1r. This fragment contains the C-terminal serine protease (SP) domain and the preceding two complement control protein (CCP) modules. The activated CCP1-CCP2-SP fragment makes up a dimer in a head-to-tail fashion similarly to the previously characterized zymogen. The present structure shows an increased number of stabilizing interactions. Moreover, in the crystal lattice there is an enzyme-product relationship between the C1r molecules of neighboring dimers. This enzyme-product complex exhibits the crucial S1-P1 salt bridge between Asp631 and Arg446 residues, and intermolecular interaction between the CCP2 module and the SP domain. Based on these novel structural information we propose a new split-and-reassembly model for the autoactivation of the C1r. This model is consistent with experimental results that have not been explained adequately by previous models. It allows autoactivation of C1r without large-scale, directed movement of C1q arms. The model is concordant with the stability of the C1 complex during activation of the next complement components.
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Wallis R. Interactions between mannose-binding lectin and MASPs during complement activation by the lectin pathway. Immunobiology 2006; 212:289-99. [PMID: 17544814 PMCID: PMC2592599 DOI: 10.1016/j.imbio.2006.11.004] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2006] [Revised: 11/02/2006] [Accepted: 11/07/2006] [Indexed: 11/30/2022]
Abstract
The lectin pathway of complement performs a key role within the immune system by recognising pathogens through patterns of sugar moieties displayed on their cell surfaces and neutralising them via an antibody-independent reaction cascade. While particularly important during early childhood before the adaptive immune system is established, or when adaptive immunity is compromised, it has a protective function throughout life, neutralising invading pathogens directly and helping to stimulate and direct an effective immune response. Complement activation is initiated when complexes comprising mannose-binding lectin (MBL) or serum ficolins and MBL-associated serine protease-2 (MASP-2) bind to pathogens. Binding induces conformational changes in these complexes, leading to autoactivation of the MASPs, which in turn activate the downstream reaction cascade. A major goal in complement research is to understand the molecular events that trigger complement activation. Over the last few years, structure–function studies have improved our knowledge of the way in which MBL binds to MASPs by defining the portions of these proteins that interact and by solving the structures of key protein fragments. In this review, I will summarise the main findings of these studies and describe current theories to explain how the components combine to initiate the reaction cascade.
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Affiliation(s)
- Russell Wallis
- Departments of Infection, Immunity and Inflammation and Biochemistry, University of Leicester, Leicester, UK.
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