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Shirani M, Shariati S, Bazdar M, Sojoudi Ghamnak F, Moradi M, Shams Khozani R, Taki E, Arabsorkhi Z, Heidary M, Eskandari DB. The immunopathogenesis of Helicobacter pylori-induced gastric cancer: a narrative review. Front Microbiol 2024; 15:1395403. [PMID: 39035439 PMCID: PMC11258019 DOI: 10.3389/fmicb.2024.1395403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2024] [Accepted: 05/06/2024] [Indexed: 07/23/2024] Open
Abstract
Helicobacter pylori infection is a well-established risk factor for the development of gastric cancer (GC). Understanding the immunopathogenesis underlying this association is crucial for developing effective preventive and therapeutic strategies. This narrative review comprehensively explores the immunopathogenesis of H. pylori-induced GC by delving into several key aspects, emphasizing the pivotal roles played by H. pylori virulence factors, including cytotoxin-associated gene A (cagA) and vacuolating cytotoxin A (vacA), blood group antigen-binding adhesin (babA), and sialic acid binding adhesin (sabA). Moreover, the review focuses on the role of toll-like receptors (TLRs) and cytokines in the complex interplay between chronic infection and gastric carcinogenesis. Finally, the study examines the association between H. pylori evasion of the innate and adaptive immune response and development of GC. A comprehensive understanding of the immunopathogenesis of H. pylori-induced GC is essential for designing targeted interventions to prevent and manage this disease. Further research is warranted to elucidate the intricate immune responses involved and identify potential therapeutic targets to improve patient outcomes.
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Affiliation(s)
- Maryam Shirani
- Toxicology Research Center, Medical Basic Sciences Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Saeedeh Shariati
- Toxicology Research Center, Medical Basic Sciences Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
- Student Research Committee, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Monireh Bazdar
- School of Medicine, Razi Hospital, Ilam University of Medical Sciences, Ilam, Iran
| | | | - Melika Moradi
- Department of Microbiology, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | | | - Elahe Taki
- Department of Microbiology, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Zahra Arabsorkhi
- Department of Medical Genetics, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran
| | - Mohsen Heidary
- Department of Laboratory Sciences, School of Paramedical Sciences, Sabzevar University of Medical Sciences, Sabzevar, Iran
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Abe R, Ram-Mohan N, Yang S. Re-visiting humoral constitutive antibacterial heterogeneity in bloodstream infections. THE LANCET. INFECTIOUS DISEASES 2024; 24:e245-e251. [PMID: 37944543 DOI: 10.1016/s1473-3099(23)00494-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 07/03/2023] [Accepted: 07/25/2023] [Indexed: 11/12/2023]
Abstract
Although cellular immunity has garnered much attention in the era of single-cell technologies, humoral innate immunity has receded in priority due to its presumed limited roles. Hence, despite the long-recognised bactericidal activity of serum-a functional characteristic of constitutive humoral immunity-much remains unclear regarding mechanisms underlying its inter-individual heterogeneity and clinical implications in bloodstream infections. Recent work suggests that the immediate antimicrobial effect of humoral innate immunity contributes to suppression of the excessive inflammatory responses to infection by reducing the amount of pathogen-associated molecular patterns. In this Personal View, we propose the need to re-explore factors underlying the inter-individual heterogeneity in serum antibacterial competence as a new approach to better understand humoral innate immunity and revisit the clinical use of measuring serum antibacterial activity in the management of bacterial bloodstream infections. Given the current emphasis on subtyping sepsis, a serum bactericidal assay might prove useful in defining a distinct sepsis endotype, to enable more personalised management.
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Affiliation(s)
- Ryuichiro Abe
- Department of Emergency Medicine, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Nikhil Ram-Mohan
- Department of Emergency Medicine, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Samuel Yang
- Department of Emergency Medicine, Stanford University School of Medicine, Palo Alto, CA, USA.
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3
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Heggi MT, Nour El-Din HT, Morsy DI, Abdelaziz NI, Attia AS. Microbial evasion of the complement system: a continuous and evolving story. Front Immunol 2024; 14:1281096. [PMID: 38239357 PMCID: PMC10794618 DOI: 10.3389/fimmu.2023.1281096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 11/30/2023] [Indexed: 01/22/2024] Open
Abstract
The complement system is a fundamental part of the innate immune system that plays a key role in the battle of the human body against invading pathogens. Through its three pathways, represented by the classical, alternative, and lectin pathways, the complement system forms a tightly regulated network of soluble proteins, membrane-expressed receptors, and regulators with versatile protective and killing mechanisms. However, ingenious pathogens have developed strategies over the years to protect themselves from this complex part of the immune system. This review briefly discusses the sequence of the complement activation pathways. Then, we present a comprehensive updated overview of how the major four pathogenic groups, namely, bacteria, viruses, fungi, and parasites, control, modulate, and block the complement attacks at different steps of the complement cascade. We shed more light on the ability of those pathogens to deploy more than one mechanism to tackle the complement system in their path to establish infection within the human host.
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Affiliation(s)
- Mariam T. Heggi
- Clinical Pharmacy Undergraduate Program, Faculty of Pharmacy, Cairo University, Cairo, Egypt
| | - Hanzada T. Nour El-Din
- Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo, Egypt
| | | | | | - Ahmed S. Attia
- Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo, Egypt
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4
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Zaruba M, Roschitz L, Sami H, Ogris M, Gerner W, Metzner C. Surface Modification of E. coli Outer Membrane Vesicles with Glycosylphosphatidylinositol-Anchored Proteins: Generating Pro/Eukaryote Chimera Constructs. MEMBRANES 2021; 11:membranes11060428. [PMID: 34199851 PMCID: PMC8228533 DOI: 10.3390/membranes11060428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Revised: 05/25/2021] [Accepted: 05/27/2021] [Indexed: 11/19/2022]
Abstract
Extracellular vesicles produced by different types of cells have recently attracted great attention, not only for their role in physiology and pathology, but also because of the emerging applications in gene therapy, vaccine production and diagnostics. Less well known than their eukaryotic counterpart, also bacteria produce extracellular vesicles, in the case of the Gram-negative E. coli the main species is termed outer membrane vesicles (OMVs). In this study, we show for the first time the functional surface modification of E. coli OMVs with glycosylphosphatidylinositol (GPI)-anchored protein, exploiting a process variably described as molecular painting or protein engineering in eukaryotic membranes, whereby the lipid part of the GPI anchor inserts in cell membranes. By transferring the process to bacterial vesicles, we can generate a hybrid of perfectly eukaryotic proteins (in terms of folding and post-translational modifications) on a prokaryotic platform. We could demonstrate that two different GPI proteins can be displayed on the same OMV. In addition to fluorescent marker proteins, cytokines, growth factors and antigens canb be potentially transferred, generating a versatile modular platform for a novel vaccine strategy.
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Affiliation(s)
- Marianne Zaruba
- Institute of Virology, University of Veterinary Medicine Vienna, 1210 Vienna, Austria; (M.Z.); (L.R.)
| | - Lena Roschitz
- Institute of Virology, University of Veterinary Medicine Vienna, 1210 Vienna, Austria; (M.Z.); (L.R.)
| | - Haider Sami
- Laboratory of Macromolecular Cancer Therapeutics MMCT, Department of Pharmaceutical Sciences, University of Vienna, 1090 Vienna, Austria; (H.S.); (M.O.)
| | - Manfred Ogris
- Laboratory of Macromolecular Cancer Therapeutics MMCT, Department of Pharmaceutical Sciences, University of Vienna, 1090 Vienna, Austria; (H.S.); (M.O.)
| | - Wilhelm Gerner
- Institute of Immunology, University of Veterinary Medicine Vienna, 1210 Vienna, Austria;
| | - Christoph Metzner
- Institute of Virology, University of Veterinary Medicine Vienna, 1210 Vienna, Austria; (M.Z.); (L.R.)
- Correspondence:
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5
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Luo SW, Wei W, Yang P, Lai CM, Liang QJ, Liu Y, Wang WN. Characterization of a CD59 in orange-spotted grouper (Epinephelus coioides). FISH & SHELLFISH IMMUNOLOGY 2019; 89:486-497. [PMID: 30980917 DOI: 10.1016/j.fsi.2019.04.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 04/04/2019] [Accepted: 04/06/2019] [Indexed: 06/09/2023]
Abstract
CD59, a multifunctional glycoprotein, not only plays a regulatory role in complement cascades, but also participates in modulation of teleostean immunity. In this study, full length sequence of EcCD59 was obtained, comprising a 5'UTR of 163 bp, an ORF of 354 bp and a 3'UTR of 559 bp. EcCD59 gene encoded a polypeptide of 117 amino acids. Tissue-specific analysis revealed that the highest expression of EcCD59 mRNA was observed in muscle. Vibrio alginolyticus challenge can significantly increase EcCD59 mRNA expression in liver, kidney and spleen. EcCD59 distribution was detected by a combined approach using GFP-overexpression, immunofluorescence and ELISA assay, indicating that EcCD59 may be predominantly aggregated in cellular membrane. Both EcCD59 and EcCD59delGPI can directly bind to V. alginolyticus and decrease the in vitro growth of V. alginolyticus. Additionally, vibrio injection experiment indicated that the binding of EcCD59 or EcCD59delGPI to V. alginolyticus can restrict its growth rate in vivo. In this study, we found that EcCD59 may be involved in immune defense against vibrio infection in a complement-independent manner.
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Affiliation(s)
- Sheng-Wei Luo
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, College of Life Science, South China Normal University, Guangzhou, 510631, PR China; State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, 410081, PR China
| | - Wei Wei
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, College of Life Science, South China Normal University, Guangzhou, 510631, PR China
| | - Ping Yang
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, College of Life Science, South China Normal University, Guangzhou, 510631, PR China
| | - Chu-Min Lai
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, College of Life Science, South China Normal University, Guangzhou, 510631, PR China
| | - Qing-Jian Liang
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, College of Life Science, South China Normal University, Guangzhou, 510631, PR China
| | - Yuan Liu
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, College of Life Science, South China Normal University, Guangzhou, 510631, PR China
| | - Wei-Na Wang
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, College of Life Science, South China Normal University, Guangzhou, 510631, PR China.
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The Functional Amyloid Curli Protects Escherichia coli against Complement-Mediated Bactericidal Activity. Biomolecules 2018; 8:biom8010005. [PMID: 29364839 PMCID: PMC5871974 DOI: 10.3390/biom8010005] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 01/08/2018] [Accepted: 01/16/2018] [Indexed: 12/30/2022] Open
Abstract
Escherichia coli strains may be beneficial or pathogenic. Many E. coli strains that cause human disease, especially those responsible for bacteremia and sepsis, express virulence factors that impart resistance to the complement system. The bacterial amyloid curli functions in bacterial adherence and enhances the formation of biofilms. Survival of curli-producing parental and curli-deficient mutant E. coli in the context of a human complement response was evaluated using an in vivo murine model of bacteremia. Results showed that curli production enhanced E. coli survival, which suggests that curli defends against complement-mediated killing. This observation was supported by the results of in vitro assays comparing bacterial survival in human serum. Experiments in which the classical or alternative complement pathways were blocked indicated that the classical pathway is the major contributor to complement activation and that curli inhibits this activity. Our analyses indicate that curli does not appear to play a role in protecting E. coli against alternative pathway complement activation. We found that curli increases binding of E. coli cells to complement component Complement component 1q (C1q) but does not affect Complement component 3b (C3b) binding. We conclude that curli defends E. coli against complement-mediated killing via inhibition of the classical complement pathway.
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7
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Sui ZH, Li MF, Sun L. Tongue sole (Cynoglossus semilaevis) CD59: A complement inhibitor that binds bacterial cells and promotes bacterial escape from the killing of fish serum. FISH & SHELLFISH IMMUNOLOGY 2016; 58:442-448. [PMID: 27688119 DOI: 10.1016/j.fsi.2016.09.051] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 09/23/2016] [Accepted: 09/25/2016] [Indexed: 06/06/2023]
Abstract
CD59 is a complement regulatory protein that inhibits the formation of membrane attack complex of complement. In this study, we examined the expression and activity of tongue sole (Cynoglossus semilaevis) CD59 (CsCD59). CsCD59 possesses the conserved structural features of CD59 and shares 33%-46% sequence identities with other fish CD59. Expression of CsCD59 was high in liver, spleen, and muscle, and was stimulated by infection of bacterial pathogens. Recombinant CsCD59 (rCsCD59) exhibited an apparent inhibition effect on the activation of tongue sole serum complement. ELISA and microscopy detected binding of rCsCD59 to a number of Gram-negative and Gram-positive bacteria. Interaction with rCsCD59 did not affect bacterial viability but significantly enhanced bacterial resistance against the killing effect of fish serum. Together these results indicate that fish CD59 may to some degrees facilitate a general escape of bacteria from complement-mediated immunity.
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Affiliation(s)
- Zhi-Hai Sui
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China; University of Chinese Academy of Sciences, Beijing, China
| | - Mo-Fei Li
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Li Sun
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.
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8
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Heider S, Dangerfield JA, Metzner C. Biomedical applications of glycosylphosphatidylinositol-anchored proteins. J Lipid Res 2016; 57:1778-1788. [PMID: 27542385 PMCID: PMC5036375 DOI: 10.1194/jlr.r070201] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Indexed: 01/13/2023] Open
Abstract
Glycosylphosphatidylinositol (GPI)-anchored proteins (GPI-APs) use a unique posttranslational modification to link proteins to lipid bilayer membranes. The anchoring structure consists of both a lipid and carbohydrate portion and is highly conserved in eukaryotic organisms regarding its basic characteristics, yet highly variable in its molecular details. The strong membrane targeting property has made the anchors an interesting tool for biotechnological modification of lipid membrane-covered entities from cells through extracellular vesicles to enveloped virus particles. In this review, we will take a closer look at the mechanisms and fields of application for GPI-APs in lipid bilayer membrane engineering and discuss their advantages and disadvantages for biomedicine.
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Affiliation(s)
- Susanne Heider
- Institute of Virology, University of Veterinary Medicine, 1210 Vienna, Austria
| | | | - Christoph Metzner
- Institute of Virology, University of Veterinary Medicine, 1210 Vienna, Austria.
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9
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Berends ETM, Kuipers A, Ravesloot MM, Urbanus RT, Rooijakkers SHM. Bacteria under stress by complement and coagulation. FEMS Microbiol Rev 2014; 38:1146-71. [PMID: 25065463 DOI: 10.1111/1574-6976.12080] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Revised: 06/23/2014] [Accepted: 07/14/2014] [Indexed: 02/03/2023] Open
Abstract
The complement and coagulation systems are two related protein cascades in plasma that serve important roles in host defense and hemostasis, respectively. Complement activation on bacteria supports cellular immune responses and leads to direct killing of bacteria via assembly of the Membrane Attack Complex (MAC). Recent studies have indicated that the coagulation system also contributes to mammalian innate defense since coagulation factors can entrap bacteria inside clots and generate small antibacterial peptides. In this review, we will provide detailed insights into the molecular interplay between these protein cascades and bacteria. We take a closer look at how these pathways are activated on bacterial surfaces and discuss the mechanisms by which they directly cause stress to bacterial cells. The poorly understood mechanism for bacterial killing by the MAC will be reevaluated in light of recent structural insights. Finally, we highlight the strategies used by pathogenic bacteria to modulate these protein networks. Overall, these insights will contribute to a better understanding of the host defense roles of complement and coagulation against bacteria.
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Affiliation(s)
- Evelien T M Berends
- Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
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10
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Miajlovic H, Smith SG. Bacterial self-defence: how Escherichia coli evades serum killing. FEMS Microbiol Lett 2014; 354:1-9. [PMID: 24617921 DOI: 10.1111/1574-6968.12419] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Revised: 03/04/2014] [Accepted: 03/05/2014] [Indexed: 12/19/2022] Open
Abstract
The ability to survive the bactericidal action of serum is advantageous to extraintestinal pathogenic Escherichia coli that gain access to the bloodstream. Evasion of the innate defences present in serum, including complement and antimicrobial peptides, involves multiple factors. Serum resistance mechanisms utilized by E. coli include the production of protective extracellular polysaccharide capsules and expression of factors that inhibit or interfere with the complement cascade. Recent studies have also highlighted the importance of structural integrity of the cell envelope in serum survival. These survival strategies are outlined in this review with particular attention to novel findings and recent insights into well-established resistance mechanisms.
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Affiliation(s)
- Helen Miajlovic
- Department of Clinical Microbiology, Sir Patrick Dun Research Laboratory, School of Medicine, Trinity College, Dublin, Ireland
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11
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Potempa M, Potempa J. Protease-dependent mechanisms of complement evasion by bacterial pathogens. Biol Chem 2013; 393:873-88. [PMID: 22944688 DOI: 10.1515/hsz-2012-0174] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Accepted: 05/06/2012] [Indexed: 12/11/2022]
Abstract
The human immune system has evolved a variety of mechanisms for the primary task of neutralizing and eliminating microbial intruders. As the first line of defense, the complement system is responsible for rapid recognition and opsonization of bacteria, presentation to phagocytes and bacterial cell killing by direct lysis. All successful human pathogens have mechanisms of circumventing the antibacterial activity of the complement system and escaping this stage of the immune response. One of the ways in which pathogens achieve this is the deployment of proteases. Based on the increasing number of recent publications in this area, it appears that proteolytic inactivation of the antibacterial activities of the complement system is a common strategy of avoiding targeting by this arm of host innate immune defense. In this review, we focus on those bacteria that deploy proteases capable of degrading complement system components into non-functional fragments, thus impairing complement-dependent antibacterial activity and facilitating pathogen survival inside the host.
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Affiliation(s)
- Michal Potempa
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Krakow, Poland.
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12
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Friberg N, Carlson P, Kentala E, Mattila PS, Kuusela P, Meri S, Jarva H. Factor H Binding as a Complement Evasion Mechanism for an Anaerobic Pathogen,Fusobacterium necrophorum. THE JOURNAL OF IMMUNOLOGY 2008; 181:8624-32. [DOI: 10.4049/jimmunol.181.12.8624] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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13
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Lambris JD, Ricklin D, Geisbrecht BV. Complement evasion by human pathogens. Nat Rev Microbiol 2008; 6:132-42. [PMID: 18197169 DOI: 10.1038/nrmicro1824] [Citation(s) in RCA: 542] [Impact Index Per Article: 33.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The human immune system has developed an elaborate network of cascades for dealing with microbial intruders. Owing to its ability to rapidly recognize and eliminate microorganisms, the complement system is an essential and efficient component of this machinery. However, many pathogenic organisms have found ways to escape the attack of complement through a range of different mechanisms. Recent discoveries in this field have provided important insights into these processes on a molecular level. These vital developments could augment our knowledge of the pathology and treatment of infectious and inflammatory diseases.
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Affiliation(s)
- John D Lambris
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, 422 Curie Boulevard, Philadelphia, Pennsylvania 19104, USA.
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Attia AS, Ram S, Rice PA, Hansen EJ. Binding of vitronectin by the Moraxella catarrhalis UspA2 protein interferes with late stages of the complement cascade. Infect Immun 2006; 74:1597-611. [PMID: 16495531 PMCID: PMC1418666 DOI: 10.1128/iai.74.3.1597-1611.2006] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Many Moraxella catarrhalis strains are resistant to the bactericidal activity of normal human serum (NHS). The UspA2 protein of the serum-resistant strain O35E has previously been shown to be directly involved in conferring serum resistance on this strain. Testing of 11 additional serum-resistant M. catarrhalis wild-type isolates and their uspA1 and uspA2 mutants showed that the uspA1 mutants of all 11 strains were consistently serum resistant and that the uspA2 mutants of these same 11 strains were always serum sensitive. Analysis of complement deposition on four different serum-resistant M. catarrhalis strains and their serum-sensitive uspA2 mutants showed that, for three of these four strain sets, the wild-type and mutant strains bound similar amounts of early complement components. In contrast, there was a significant reduction in the amount of the polymerized C9 on the wild-type strains relative to that on the uspA2 mutants. These same three wild-type strains bound more vitronectin than did their uspA2 mutants. UspA2 proteins from these three strains, when expressed in Haemophilus influenzae, bound vitronectin and conferred serum resistance on this organism. Furthermore, vitronectin-depleted NHS exhibited bactericidal activity against these same three serum-resistant wild-type strains; addition of purified vitronectin to this serum restored serum resistance. In contrast, binding of the complement regulator C4b-binding protein by the M. catarrhalis strains used in this study was found to be highly variable and did not appear to correlate with the serum-resistant phenotype. These results indicate that binding of vitronectin by UspA2 is involved in the serum resistance of M. catarrhalis; this represents the first example of vitronectin-mediated serum resistance on a microbe.
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Affiliation(s)
- Ahmed S Attia
- Department of Microbiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9048, USA
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15
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Kraiczy P, Würzner R. Complement escape of human pathogenic bacteria by acquisition of complement regulators. Mol Immunol 2006; 43:31-44. [PMID: 16011850 DOI: 10.1016/j.molimm.2005.06.016] [Citation(s) in RCA: 112] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Pathogenic micro-organisms employ a broad range of strategies to survive in and to persistently infect the human host. Far from being completely understood by which highly sophisticated means invading pathogens overcome the host's destructive immune defence, there is a growing body of evidence on particular mechanisms which play a pivotal role for immune evasion. This review focuses on evasion of medically and scientifically important bacteria by acquisition of host derived fluid-phase complement regulatory proteins, in particular factor H, FHL-1, and C4b binding protein. Expression of microbial surface molecules binding to human complement regulators and thus fixing them in a functionally active state allows pathogens to inhibit and finely regulate complement activation directly on their surface. Further studies on the utilization of host complement regulatory proteins will likely have a marked impact on a more efficient and specific clinical treatment.
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Affiliation(s)
- Peter Kraiczy
- Institute of Medical Microbiology, University Hospital of Frankfurt, Paul-Ehrlich-Str. 40, D-60596 Frankfurt, Germany.
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16
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Simmons WL, Dybvig K. The Vsa proteins modulate susceptibility of Mycoplasma pulmonis to complement killing, hemadsorption, and adherence to polystyrene. Infect Immun 2003; 71:5733-8. [PMID: 14500494 PMCID: PMC201092 DOI: 10.1128/iai.71.10.5733-5738.2003] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2003] [Revised: 06/26/2003] [Accepted: 07/18/2003] [Indexed: 11/20/2022] Open
Abstract
The variable surface antigens (Vsa) of the murine respiratory pathogen Mycoplasma pulmonis are associated with the virulence of the microorganism in the lung. In strain UAB CT, the antigens consist of an N-terminal region that is combined with one of seven different C-terminal variable regions comprised of tandem repeats. M. pulmonis producing a VsaA protein with about 40 tandem repeats (R40) does not adhere to red blood cells or polystyrene. Strains that produce VsaH contain a short C-terminal region that lacks tandem repeats and adhere to red blood cells and plastic. We isolated and analyzed M. pulmonis strain CT variants (CT182 and derivatives) that produced a VsaA protein with only three tandem repeats (R3). These variants adhered to plastic and red blood cells similarly to the VsaH-producing strain. When the R3-producing CT182 strain or the VsaH-producing strains were incubated with normal guinea pig serum, they were efficiently killed. Killing was abolished when the serum was heat inactivated. In contrast, the M. pulmonis strains that produced VsaA R40 were highly resistant to complement killing. CT182R3 variants that survived the complement killing reactions all produced the R40 form of VsaA and were resistant to complement killing. VsaA R40 is the first mycoplasmal protein shown to be associated with resistance to complement. As both VsaH and VsaA can mediate adherence to plastic, cytadherence, and susceptibility to complement, we propose that Vsa modulates these phenotypes by nonspecific interactions.
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Affiliation(s)
- Warren L Simmons
- Department of Genetics, University of Alabama at Birmingham, 720 South 20th Street, Kaul Room 720, Birmingham, AL 35294, USA.
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Pausa M, Pellis V, Cinco M, Giulianini PG, Presani G, Perticarari S, Murgia R, Tedesco F. Serum-resistant strains of Borrelia burgdorferi evade complement-mediated killing by expressing a CD59-like complement inhibitory molecule. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 170:3214-22. [PMID: 12626580 DOI: 10.4049/jimmunol.170.6.3214] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Borrelia burgdorferi, the etiological agent of Lyme disease, comprises three genospecies, Borrelia garinii, afzelii, and burgdorferi sensu strictu, that exhibit different pathogenicity and differ in the susceptibility to C-mediated killing. We examined C-sensitive and C-resistant strains of B. burgdorferi for deposition of C3 and late C components by fluorescence microscope and flow cytometry. Despite comparable deposition of C3 on the two strains, the resistant strain exhibited reduced staining for C6 and C7, barely detectable C9, and undetectable poly C9. Based on these findings, we searched for a protein that inhibits assembly of C membrane attack complex and documented an anti-human CD59-reactive molecule on the surface of C-resistant spirochetes by flow cytometry and electron microscopy. A molecule of 80 kDa recognized by polyclonal and monoclonal anti-CD59 Abs was identified in the membrane extract of C-resistant strains by SDS-PAGE and Western blot analysis. The molecule was released from the bacterial wall using deoxycholate and trypsin, suggesting its insertion into the bacterial membrane. The CD59-like molecule acts as C inhibitor on Borrelia because incubation with F(ab')(2) anti-CD59 renders the serum-resistant strain exquisitely susceptible to C-mediated killing and guinea pig erythrocytes bearing C5b-8, unlike the RBC coated with C5b-7, are protected from reactive lysis by the bacterial extract. Western blot analysis revealed preferential binding of the C inhibitory molecule to C9 and weak interaction with C8 beta.
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Affiliation(s)
- Mario Pausa
- Department of Physiology and Pathology, University of Trieste, Trieste, Italy
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Ocaña-Morgner C, Dankert JR. Induction of complement sensitivity in Escherichia coli by citric acid and low pH. J Appl Microbiol 2001; 90:771-8. [PMID: 11348438 DOI: 10.1046/j.1365-2672.2001.01305.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIMS The lytic functions of the complement system play an important role in the control of Gram-negative infections. Complement-resistant Escherichia coli LP1395 (O18) grown under normal conditions can survive the bactericidal action of complement present in human serum. Towards elucidating the mechanisms of complement resistance, the resistance of E. coli LP1395 grown under conditions of low pH and in the presence of citric acid was tested. METHODS AND RESULTS E. coli LP1395 becomes sensitive to complement after growth in the presence of citric acid at pH 5. Complement resistance could be restored when the cells were transferred to pH 7 media. However, this recovery was greatly impaired when the cells were transferred to pH 7 media with chloramphenicol. This implies that protein synthesis may be involved in complement resistance. The cells exposed to citric acid at pH 5 showed no indication of a generalized outer membrane (OM) permeability when compared with those grown under normal conditions in terms of sensitivity to lysozyme, uptake of lipophilic dye, or sensitivity to a number of antibiotics. CONCLUSION Complement-resistant LP1395 may acquire a sensitivity to complement due not to a generalized disruption of the OM barrier, but possibly to the alteration of the activity of one or more normal complement resistance factors. SIGNIFICANCE AND IMPACT OF THE STUDY The elucidation of the mechanisms of complement resistance of Gram-negative pathogens would bring important information about bacterial infections. Complement resistance factors could also be potential targets in antimicrobial therapies.
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Affiliation(s)
- C Ocaña-Morgner
- Department of Biology, University of Louisiana at Lafayette, LA 70504-2451, USA
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Barnes MG, Weiss AA. BrkA protein of Bordetella pertussis inhibits the classical pathway of complement after C1 deposition. Infect Immun 2001; 69:3067-72. [PMID: 11292725 PMCID: PMC98261 DOI: 10.1128/iai.69.5.3067-3072.2001] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Bordetella pertussis produces a 73-kDa protein, BrkA (Bordetella resistance to killing), which inhibits the bactericidal activity of complement. In this study we characterized the step in the complement cascade where BrkA acts, using three strains: a wild-type strain, a strain containing an insertional disruption of brkA, and a strain containing two copies of the brkA locus. Following incubation with 10% human serum, killing was greatest for the BrkA mutant, followed by that for the wild-type strain, while the strain with two copies of brkA was the most resistant. Complement activation was monitored by enzyme-linked immunosorbent assay (ELISA) or Western blotting. ELISAs for SC5b-9, the soluble membrane attack complex, showed that production of SC5b-9 was greatest with the brkA mutant, less with the wild type, and least with the strain containing two copies of brkA. Deposition of complement proteins on the bacteria was monitored by Western blotting. A decrease in deposition on the bacteria of C4, C3, and C9 corresponded with decreased complement sensitivity. Deposition of C1, however, was not affected by the presence of BrkA. These studies show that BrkA inhibits the classical pathway of complement activation and prevents accumulation of deposited C4.
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Affiliation(s)
- M G Barnes
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati, Cincinnati, Ohio 45267, USA
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Rautemaa R, Rautelin H, Puolakkainen P, Kokkola A, Kärkkäinen P, Meri S. Survival of Helicobacter pylori From complement lysis by binding of GPI-anchored protectin (CD59). Gastroenterology 2001; 120:470-9. [PMID: 11159887 DOI: 10.1053/gast.2001.21197] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
BACKGROUND & AIMS Although Helicobacter pylori is sensitive to complement lysis in vitro, chronic infection persists for years. We tested whether H. pylori acquires complement resistance by binding glycolipid-tailed inhibitors from the host. METHODS Gastric biopsy specimens from H. pylori-infected patients (n = 10) and noninfected controls (n = 6) were analyzed for complement deposition and expression of the complement regulators protectin (CD59) and DAF. Protectin binding and complement sensitivity analyses were performed with the NCTC strain 11637 (CagA(+)) and 2 clinical isolates 9:0 (CagA(+)) and 67:20 (CagA(-)). RESULTS In the noninfected mucosa, protectin was strongly expressed on the membranes of epithelial cells, but in the infected epithelia the expression was granular and more focused to the mucus. H. pylori bacteria in the gastric pits were often positive for protectin but negative for C5b-9. An opposite pattern was seen on the surface mucosa. In vitro analyses using (125)I-CD59 and bacteriolysis assays showed that protectin bound to H. pylori and protected CagA(+) strains against complement killing. In an enzyme-linked immunosorbent assay, the binding of CD59 correlated inversely with the appearance of the C5b-9 neoantigen. CONCLUSIONS Binding of protectin inhibits membrane attack complex assembly on H. pylori and may thereby contribute to their survival on the gastric mucosa.
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Affiliation(s)
- R Rautemaa
- Department of Bacteriology and Immunology, Haartman Institute, University of Helsinki, Helsinki, Finland.
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Abstract
Despite more than a century of parallel research on bacteria and the complement system, relatively little is known of the mechanisms whereby pathogenic bacteria can escape complement-related opsonophagocytosis and direct killing. It is likely that pathogenicity in bacteria has arisen more accidentally than in viruses, and on the basis of selection from natural mutants rather than by outright stealing or copying of genetic codes from the host. In this review we will discuss complement resistance as one of the features that makes a bacterium a pathogen.
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Affiliation(s)
- R Rautemaa
- Department of Bacteriology and Immunology, Haartman Institute, University of Helsinki, Finland
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