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Lê-Bury P, Echenique-Rivera H, Pizarro-Cerdá J, Dussurget O. Determinants of bacterial survival and proliferation in blood. FEMS Microbiol Rev 2024; 48:fuae013. [PMID: 38734892 PMCID: PMC11163986 DOI: 10.1093/femsre/fuae013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 04/29/2024] [Accepted: 05/10/2024] [Indexed: 05/13/2024] Open
Abstract
Bloodstream infection is a major public health concern associated with high mortality and high healthcare costs worldwide. Bacteremia can trigger fatal sepsis whose prevention, diagnosis, and management have been recognized as a global health priority by the World Health Organization. Additionally, infection control is increasingly threatened by antimicrobial resistance, which is the focus of global action plans in the framework of a One Health response. In-depth knowledge of the infection process is needed to develop efficient preventive and therapeutic measures. The pathogenesis of bloodstream infection is a dynamic process resulting from the invasion of the vascular system by bacteria, which finely regulate their metabolic pathways and virulence factors to overcome the blood immune defenses and proliferate. In this review, we highlight our current understanding of determinants of bacterial survival and proliferation in the bloodstream and discuss their interactions with the molecular and cellular components of blood.
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Affiliation(s)
- Pierre Lê-Bury
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Yersinia Research Unit, 28 rue du Dr Roux, 75015 Paris, France
- Université Paris-Saclay, Inserm, CEA, Center for Immunology of Viral, Autoimmune, Hematological and Bacterial Diseases (IMVA-HB/IDMIT), 18 route du Panorama, 92260 Fontenay-aux-Roses, France
| | - Hebert Echenique-Rivera
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Yersinia Research Unit, 28 rue du Dr Roux, 75015 Paris, France
| | - Javier Pizarro-Cerdá
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Yersinia Research Unit, 28 rue du Dr Roux, 75015 Paris, France
- Institut Pasteur, Université Paris Cité, Yersinia National Reference Laboratory, WHO Collaborating Research & Reference Centre for Plague FRA-146, 28 rue du Dr Roux, 75015 Paris, France
| | - Olivier Dussurget
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Yersinia Research Unit, 28 rue du Dr Roux, 75015 Paris, France
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2
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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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3
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Kou TS, Wu JH, Chen XW, Chen ZG, Zheng J, Peng B. Exogenous glycine promotes oxidation of glutathione and restores sensitivity of bacterial pathogens to serum-induced cell death. Redox Biol 2022; 58:102512. [PMID: 36306677 PMCID: PMC9615314 DOI: 10.1016/j.redox.2022.102512] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Revised: 10/12/2022] [Accepted: 10/14/2022] [Indexed: 11/05/2022] Open
Abstract
Pathogenic strains of bacteria are often highly adept at evading serum-induced cell death, which is an essential complement-mediated component of the innate immune response. This phenomenon, known as serum-resistance, is poorly understood, and as a result, no effective clinical tools are available to restore serum-sensitivity to pathogenic bacteria. Here, we provide evidence that exogenous glycine reverses defects in glycine, serine and threonine metabolism associated with serum resistance, restores susceptibility to serum-induced cell death, and alters redox balance and glutathione (GSH) metabolism. More specifically, in Vibrio alginolyticus and Escherichia coli, exogenous glycine promotes oxidation of GSH to GSH disulfide (GSSG), disrupts redox balance, increases oxidative stress and reduces membrane integrity, leading to increased binding of complement. Antioxidant or ROS scavenging agents abrogate this effect and agents that generate or potentiate oxidation stimulate serum-mediated cell death. Analysis of several clinical isolates of E. coli demonstrates that glutathione metabolism is repressed in serum-resistant bacteria. These data suggest a novel mechanism underlying serum-resistance in pathogenic bacteria, characterized by an induced shift in the GSH/GSSG ratio impacting redox balance. The results could potentially lead to novel approaches to manage infections caused by serum-resistant bacteria both in aquaculture and human health.
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Affiliation(s)
- Tian-shun Kou
- Center for Proteomics and Metabolomics, State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Higher Education Mega Center, Guangzhou, 510006, People's Republic of China,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China
| | - Jia-han Wu
- Center for Proteomics and Metabolomics, State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Higher Education Mega Center, Guangzhou, 510006, People's Republic of China,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China
| | - Xuan-wei Chen
- Center for Proteomics and Metabolomics, State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Higher Education Mega Center, Guangzhou, 510006, People's Republic of China,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China
| | - Zhuang-gui Chen
- Department of Pediatrics, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510006, China
| | - Jun Zheng
- Faculty of Health Sciences, University of Macau, Macau SAR, China
| | - Bo Peng
- Center for Proteomics and Metabolomics, State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Higher Education Mega Center, Guangzhou, 510006, People's Republic of China,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China,Corresponding author. State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Higher Education Mega Center, Guangzhou 510006, People's Republic of China.
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4
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Liyanagedera SBW, Williams J, Wheatley JP, Biketova AY, Hasan M, Sagona AP, Purdy KJ, Puxty RJ, Feher T, Kulkarni V. SpyPhage: A Cell-Free TXTL Platform for Rapid Engineering of Targeted Phage Therapies. ACS Synth Biol 2022; 11:3330-3342. [PMID: 36194543 DOI: 10.1021/acssynbio.2c00244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The past decade has seen the emergence of multidrug resistant pathogens as a leading cause of death worldwide, reigniting interest in the field of phage therapy. Modern advances in the genetic engineering of bacteriophages have enabled several useful results including host range alterations, constitutive lytic growth, and control over phage replication. However, the slow licensing process of genetically modified organisms clearly inhibits the rapid therapeutic application of novel engineered variants necessary to fight mutant pathogens that emerge throughout the course of a pandemic. As a solution to this problem, we propose the SpyPhage system where a "scaffold" bacteriophage is engineered to incorporate a SpyTag moiety on its capsid head to enable rapid postsynthetic modification of their surfaces with SpyCatcher-fused therapeutic proteins. As a proof of concept, through CRISPR/Cas-facilitated phage engineering and whole genome assembly, we targeted a SpyTag capsid fusion to K1F, a phage targeting the pathogenic strain Escherichia coli K1. We demonstrate for the first time the cell-free assembly and decoration of the phage surface with two alternative fusion proteins, SpyCatcher-mCherry-EGF and SpyCatcher-mCherry-Rck, both of which facilitate the endocytotic uptake of the phages by a urinary bladder epithelial cell line. Overall, our work presents a cell-free phage production pipeline for the generation of multiple phenotypically distinct phages with a single underlying "scaffold" genotype. These phages could become the basis of next-generation phage therapies where the knowledge-based engineering of numerous phage variants would be quickly achievable without the use of live bacteria or the need to repeatedly license novel genetic alterations.
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Affiliation(s)
| | - Joshua Williams
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Joseph P Wheatley
- School of Engineering, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Alona Yu Biketova
- Institute of Biochemistry, Eötvös Lóránd Research Network, Szeged Biological Research Centre, Szeged 6726, Hungary.,Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond TW9 3AE, United Kingdom
| | - Muhammad Hasan
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Antonia P Sagona
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Kevin J Purdy
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Richard J Puxty
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Tamas Feher
- Institute of Biochemistry, Eötvös Lóránd Research Network, Szeged Biological Research Centre, Szeged 6726, Hungary
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5
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Krzyżewska-Dudek E, Kotimaa J, Kapczyńska K, Rybka J, Meri S. Lipopolysaccharides and outer membrane proteins as main structures involved in complement evasion strategies of non-typhoidal Salmonella strains. Mol Immunol 2022; 150:67-77. [PMID: 35998438 DOI: 10.1016/j.molimm.2022.08.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 08/10/2022] [Accepted: 08/15/2022] [Indexed: 11/27/2022]
Abstract
Non-typhoidal Salmonella (NTS) infections pose a serious public health problem. In addition to the typical course of salmonellosis, an infection with Salmonella bacteria can often lead to parenteral infections and sepsis, which are particularly dangerous for children, the elderly and immunocompromised. Bacterial resistance to serum is a key virulence factor for the development of systemic infections. Salmonella, as an enterobacterial pathogen, has developed several mechanisms to escape and block the antibacterial effects of the complement system. In this review, we discuss the relevance of outer membrane polysaccharides to the complement evasion mechanisms of NTS strains. These include the influence of the overall length and density of the lipopolysaccharide molecules, modifications of the O-antigen lipopolysaccharide composition and the role of capsular polysaccharides in opsonization and protection of the outer membrane from the lytic action of complement. Additionally, we discuss specific outer membrane protein complement evasion mechanisms, such as recruitment of complement regulatory proteins, blocking assembly of late complement components to form the membrane attack complex and the proteolytic cleavage of complement proteins.
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Affiliation(s)
- E Krzyżewska-Dudek
- Department of Bacteriology and Immunology, Translational Immunology Research Program, University of Helsinki, and Diagnostic Center (HUSLAB), Helsinki University Hospital, 00290 Helsinki, Finland; Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, 53-114 Wroclaw, Poland
| | - J Kotimaa
- Department of Bacteriology and Immunology, Translational Immunology Research Program, University of Helsinki, and Diagnostic Center (HUSLAB), Helsinki University Hospital, 00290 Helsinki, Finland
| | - K Kapczyńska
- Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, 53-114 Wroclaw, Poland
| | - J Rybka
- Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, 53-114 Wroclaw, Poland
| | - S Meri
- Department of Bacteriology and Immunology, Translational Immunology Research Program, University of Helsinki, and Diagnostic Center (HUSLAB), Helsinki University Hospital, 00290 Helsinki, Finland.
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6
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Hermansen S, Linke D, Leo JC. Transmembrane β-barrel proteins of bacteria: From structure to function. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2022; 128:113-161. [PMID: 35034717 DOI: 10.1016/bs.apcsb.2021.07.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
The outer membrane of Gram-negative bacteria is a specialized organelle conferring protection to the cell against various environmental stresses and resistance to many harmful compounds. The outer membrane has a number of unique features, including an asymmetric lipid bilayer, the presence of lipopolysaccharides and an individual proteome. The vast majority of the integral transmembrane proteins in the outer membrane belongs to the family of β-barrel proteins. These evolutionarily related proteins share a cylindrical, anti-parallel β-sheet core fold spanning the outer membrane. The loops and accessory domains attached to the β-barrel allow for a remarkable versatility in function for these proteins, ranging from diffusion pores and transporters to enzymes and adhesins. We summarize the current knowledge on β-barrel structure and folding and give an overview of their functions, evolution, and potential as drug targets.
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Affiliation(s)
- Simen Hermansen
- Section for Genetics and Evolutionary Biology, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Dirk Linke
- Section for Genetics and Evolutionary Biology, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Jack C Leo
- Antimicrobial resistance, Omics and Microbiota Group, Department of Biosciences, Nottingham Trent University, Nottingham, United Kingdom.
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7
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Hu G, Chen X, Chu W, Ma Z, Miao Y, Luo X, Fu Y. Immunogenic characteristics of the outer membrane phosphoporin as a vaccine candidate against Klebsiella pneumoniae. Vet Res 2022; 53:5. [PMID: 35063026 PMCID: PMC8781355 DOI: 10.1186/s13567-022-01023-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 12/16/2021] [Indexed: 11/17/2022] Open
Abstract
In recent years, Klebsiella pneumoniae (KP) has caused disease outbreaks in different animals, resulting in serious economic losses and biosafety concerns. Considering the broad antibiotic resistance of KP, vaccines are the most effective tools against infection. However, there is still no KP vaccine available in the veterinary field. Our results indicate that the highly conserved outer membrane phosphoporin (PhoE) of KP is immunogenic in mice and elicits high titers of antibodies that were shown to be specific for PhoE by immunoblotting. Immunization with PhoE also induced robust cell-mediated immunity and elicited the secretion of high levels of IFN-γ and IL-4, suggesting the induction of mixed Th1 and Th2 responses. Sera from PhoE-immunized mice induced significantly higher complement-mediated lysis of KP cells than did sera from the PBS control mice. Finally, mice immunized with PhoE were significantly protected against KP challenge, with better survival and a reduced visceral bacterial load. Our data underscore the great potential of PhoE as a novel candidate antigen for a vaccine against KP infection.
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Affiliation(s)
- Gaowei Hu
- College of Life Sciences, Institute of Biomass Resources, Taizhou University, Taizhou, 318000, Zhejiang, China
| | - Xue Chen
- College of Life Sciences, Institute of Biomass Resources, Taizhou University, Taizhou, 318000, Zhejiang, China
| | - Wenhui Chu
- College of Life Sciences, Institute of Biomass Resources, Taizhou University, Taizhou, 318000, Zhejiang, China
| | - Zhe Ma
- College of Life Sciences, Institute of Biomass Resources, Taizhou University, Taizhou, 318000, Zhejiang, China
| | - Yingjie Miao
- College of Life Sciences, Institute of Biomass Resources, Taizhou University, Taizhou, 318000, Zhejiang, China
| | - Xi Luo
- College of Life Sciences, Institute of Biomass Resources, Taizhou University, Taizhou, 318000, Zhejiang, China
| | - Yongqian Fu
- College of Life Sciences, Institute of Biomass Resources, Taizhou University, Taizhou, 318000, Zhejiang, China.
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8
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The Invasin and Complement-Resistance Protein Rck of Salmonella is More Widely Distributed than Previously Expected. Microbiol Spectr 2021; 9:e0145721. [PMID: 34704781 PMCID: PMC8549739 DOI: 10.1128/spectrum.01457-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The rck open reading frame (ORF) on the pefI-srgC operon encodes an outer membrane protein responsible for invasion of nonphagocytic cell lines and resistance to complement-mediated killing. Until now, the rck ORF was only detected on the virulence plasmids of three serovars of Salmonella subsp. enterica (i.e., Bovismorbificans, Enteritidis, and Typhimurium). The increasing number of Salmonella genome sequences allowed us to use a combination of reference sequences and whole-genome multilocus sequence typing (wgMLST) data analysis to probe the presence of the operon and of rck in a wide array of isolates belonging to all Salmonella species and subspecies. We established the presence of partial or complete operons in 61 subsp. enterica serovars as well as in 4 other subspecies with various syntenies and frequencies. The rck ORF itself was retrieved in 36 subsp. enterica serovars and in two subspecies with either chromosomal or plasmid-borne localization. It displays high conservation of its sequence within the genus, and we demonstrated that most of the allelic variations identified did not alter the virulence properties of the protein. However, we demonstrated the importance of the residue at position 38 (at the level of the first extracellular loop of the protein) in the invasin function of Rck. Altogether, our results highlight that rck is not restricted to the three formerly identified serovars and could therefore have a more important role in virulence than previously expected. Moreover, this work raises questions about the mechanisms involved in rck acquisition and about virulence plasmid distribution and evolution. IMPORTANCE The foodborne pathogen Salmonella is responsible for a wide variety of pathologies depending on the infected host, the infecting serovars, and its set of virulence factors. However, the implication of each of these virulence factors and their role in the specific host-pathogen interplay are not fully understood. The significance of our research is in determining the distribution of one of these factors, the virulence plasmid-encoded invasin and resistance to complement killing protein Rck. In addition to providing elements of reflection concerning the mechanisms of acquisition of specific virulence genes in certain serotypes, this work will help to understand the role of Rck in the pathogenesis of Salmonella.
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9
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Virulence Comparison of Salmonella enterica Subsp. enterica Isolates from Chicken and Whole Genome Analysis of the High Virulent Strain S. Enteritidis 211. Microorganisms 2021; 9:microorganisms9112239. [PMID: 34835366 PMCID: PMC8619400 DOI: 10.3390/microorganisms9112239] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 10/12/2021] [Accepted: 10/20/2021] [Indexed: 01/28/2023] Open
Abstract
Background: Salmonellaenterica is one of the common pathogens in both humans and animals that causes salmonellosis and threatens public health all over the world. Methods and Results: Here we determined the virulence phenotypes of nine Salmonellaenterica subsp. enterica (S. enterica) isolates in vitro and in vivo, including pathogenicity to chicken, cell infection, biofilm formation and virulence gene expressions. S. Enteritidis 211 (SE211) was highly pathogenic with notable virulence features among the nine isolates. The combination of multiple virulence genes contributed to the conferring of the high virulence in SE211. Importantly, many mobile genetic elements (MGEs) were found in the genome sequence of SE211, including a virulence plasmid, genomic islands, and prophage regions. The MGEs and CRISPR-Cas system might function synergistically for gene transfer and immune defense. In addition, the neighbor joining tree and the minimum spanning tree were constructed in this study. Conclusions: This study provided both the virulence phenotypes and genomic features, which might contribute to the understanding of bacterial virulence mechanisms in Salmonella enterica subsp. enterica. The first completed genomic sequence for the high virulent S. Enteritidis isolate SE211 and the comparative genomics and phylogenetic analyses provided a preliminary understanding of S. enterica genetics and laid the foundation for further study.
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Li D, Wang X, Xu X, Gu J, Yang Y, Liu T, Wang S, Chen S, Li J. Duck Complement Factor H Binds to Outer Membrane Protein Omp24 of Riemerella anatipestifer. Avian Dis 2021; 65:261-268. [PMID: 34412457 DOI: 10.1637/0005-2086-65.2.261] [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: 10/24/2020] [Accepted: 03/29/2021] [Indexed: 11/05/2022]
Abstract
The resistance to serum complement-mediated killing is a vital virulence property of microbial pathogens. Complement factor H (FH) is a key negative regulator of the complement alternative pathway (AP) that prevents formation and accelerates the decay of AP C3 convertase and acts as a cofactor in the inactivation of C3b. Pathogens can recruit host FH through their surface proteins to escape the clearance of the complement system. Riemerella anatipestifer could also evade the complement system attack to achieve host infection, but the mechanism is still unclear. In this study, the R. anatipestifer proteins that could interact with FH in host serum were screened and analyzed, and the functions were determined. Affinity chromatography with a Ni-nitrilotriacetic acid Sefinose column and mass spectrometry identified three outer membrane proteins (Omp) of R. anatipestifer, Omp54, Omp53, and Omp24, as potential FH-binding proteins. We then successfully conducted the prokaryotic expression and polyclonal antibody preparation of three candidate proteins. Indirect immunofluorescence assay showed that three candidate proteins were all present in R. anatipestifer. The affinity blotting assay, anti-serum-inhibiting assay, and serum bactericidal assay presented evidence that Omp24 could bind FH. Moreover, FH bound to Omp24 was associated with resistance to the alternative pathway and functional for R. anatipestifer survival in the normal duck serum. These results suggested that R. anatipestifer Omp24 was a FH-binding protein and the interaction with FH blocked the alternative pathway. Recruitment of complement regulatory proteins may facilitate better R. anatipestifer resistance to this vital line of host defense.
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Affiliation(s)
- Delong Li
- College of Veterinary Medicine, Southwest University, Chongqing 402460, People's Republic of China.,Immunology Research Center, Medical Research Institute, Southwest University, Chongqing 402460, People's Republic of China
| | - Xiangli Wang
- College of Veterinary Medicine, Southwest University, Chongqing 402460, People's Republic of China
| | - Xingsheng Xu
- College of Veterinary Medicine, Southwest University, Chongqing 402460, People's Republic of China
| | - Jiulong Gu
- College of Veterinary Medicine, Southwest University, Chongqing 402460, People's Republic of China
| | - Yunchuan Yang
- College of Veterinary Medicine, Southwest University, Chongqing 402460, People's Republic of China
| | - Ting Liu
- College of Veterinary Medicine, Southwest University, Chongqing 402460, People's Republic of China
| | - Siyuan Wang
- College of Veterinary Medicine, Southwest University, Chongqing 402460, People's Republic of China
| | - Sihuai Chen
- College of Veterinary Medicine, Southwest University, Chongqing 402460, People's Republic of China.,Immunology Research Center, Medical Research Institute, Southwest University, Chongqing 402460, People's Republic of China
| | - Jixiang Li
- College of Veterinary Medicine, Southwest University, Chongqing 402460, People's Republic of China, .,Immunology Research Center, Medical Research Institute, Southwest University, Chongqing 402460, People's Republic of China
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11
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Li Q, Hu Y, Fei X, Du Y, Guo W, Chu D, Wang X, Wang S, Shi H. OmpC, a novel factor H-binding surface protein, is dispensable for the adherence and virulence of Salmonella enterica serovar Typhimurium. Vet Microbiol 2021; 259:109157. [PMID: 34197978 DOI: 10.1016/j.vetmic.2021.109157] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 06/15/2021] [Indexed: 11/24/2022]
Abstract
Salmonella enterica serovar Typhimurium utilizes a series of strategies to evade host innate immune defenses, including the serum complement system. Many microbial pathogens have evolved the ability to bind the complement regulatory protein factor H (FH) through their surface factor H-binding proteins (FHBPs) to circumvent the complement-mediated bactericidal effect. However, the roles of FHBPs in Salmonella pathogenesis are not well understood. In this study, we demonstrated that the survival of S. Typhimurium in human serum was decreased in a time and concentration dependent manner. Pre-incubation with FH attenuated the sensitivity of S. Typhimurium strain χ3761 to complement-mediated serum killing, suggesting FH binding enhance survival in serum. We aimed to identify novel S. Typhimurium FHBPs and characterize their biological functions. Here, six potential FHBPs were identified by two-dimensional (2D)-Far-western blot, and three of them were further confirmed to bind FH by Far-western blot and dot blot. We found that deletion of ompC (ΔompC) significantly inhibited the survival of S. Typhimurium strain χ3761 in human serum. Our results indicated that the ompC mutation does not affect χ3761 adhesion to HeLa cells. Furthermore, a mice infection model showed that deletion of ompC had no significant effect on the histopathological lesions or viability compared with the wild-type strain χ3761. In summary, these results suggested that OmpC is an important FHBP, but not a critical virulence factor of S. Typhimurium.
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Affiliation(s)
- Quan Li
- College of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, Jiangsu, China; Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China.
| | - Yuhan Hu
- College of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, Jiangsu, China; Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China.
| | - Xia Fei
- College of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, Jiangsu, China; Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China.
| | - Yuanzhao Du
- Yebio Bioengineering Co., Ltd of Qingdao, Qingdao, 266114, China.
| | - Weiwei Guo
- Yebio Bioengineering Co., Ltd of Qingdao, Qingdao, 266114, China.
| | - Dianfeng Chu
- Yebio Bioengineering Co., Ltd of Qingdao, Qingdao, 266114, China.
| | - Xiaobo Wang
- College of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, Jiangsu, China; Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China.
| | - Shifeng Wang
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, FL, 32611-0880, USA.
| | - Huoying Shi
- College of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, Jiangsu, China; Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China; Key Laboratory of Animal Infectious Diseases, Ministry of Agriculture, Yangzhou University, China; Jiangsu Key Laboratory of Preventive Veterinary Medicine, Yangzhou University, China.
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12
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Increased Production of Outer Membrane Vesicles by Salmonella Interferes with Complement-Mediated Innate Immune Attack. mBio 2021; 12:e0086921. [PMID: 34061589 PMCID: PMC8262969 DOI: 10.1128/mbio.00869-21] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacterial outer membrane vesicles (OMVs) enriched with bioactive proteins, toxins, and virulence factors play a critical role in host-pathogen and microbial interactions. The two-component system PhoP-PhoQ (PhoPQ) of Salmonella enterica orchestrates the remodeling of outer membrane lipopolysaccharide (LPS) molecules and concomitantly upregulates OMV production. In this study, we document a novel use of nanoparticle tracking analysis to determine bacterial OMV size and number. Among the PhoPQ-activated genes tested, pagC expression had the most significant effect on the upregulation of OMV production. We provide the first evidence that PhoPQ-mediated upregulation of OMV production contributes to bacterial survival by interfering with complement activation. OMVs protected bacteria in a dose-dependent manner, and bacteria were highly susceptible to complement-mediated killing in their absence. OMVs from bacteria expressing PagC bound to complement component C3b in a dose-dependent manner and inactivated it by recruiting complement inhibitor Factor H. As we also found that Factor H binds to PagC, we propose that PagC interferes with complement-mediated killing of Salmonella in the following two steps: first by engaging Factor H, and second, through the production of PagC-enriched OMVs that divert and inactivate the complement away from the bacteria. Since PhoPQ activation occurs intracellularly, the resultant increase in PagC expression and OMV production is suggested to contribute to the local and systemic spread of Salmonella released from dying host cells that supports the infection of new cells. IMPORTANCE Bacterial outer membrane vesicles (OMVs) mediate critical bacterium-bacterium and host-microbial interactions that influence pathogenesis through multiple mechanisms, including the elicitation of inflammatory responses, delivery of virulence factors, and enhancement of biofilm formation. As such, there is a growing interest in understanding the underlying mechanisms of OMV production. Recent studies have revealed that OMV biogenesis is a finely tuned physiological process that requires structural organization and selective sorting of outer membrane components into the vesicles. In Salmonella, outer membrane remodeling and OMV production are tightly regulated by its PhoPQ system. In this study, we demonstrate that PhoPQ-regulated OMV production plays a significant role in defense against host innate immune attack. PhoPQ-activated PagC expression recruits the complement inhibitor Factor H and degrades the active C3 component of complement. Our results provide valuable insight into the combination of tools and environmental signals that Salmonella employs to evade complement-mediated lysis, thereby suggesting a strong evolutionary adaptation of this facultative intracellular pathogen to protect itself during its extracellular stage in the host.
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13
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Moore SR, Menon SS, Cortes C, Ferreira VP. Hijacking Factor H for Complement Immune Evasion. Front Immunol 2021; 12:602277. [PMID: 33717083 PMCID: PMC7947212 DOI: 10.3389/fimmu.2021.602277] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 01/15/2021] [Indexed: 12/15/2022] Open
Abstract
The complement system is an essential player in innate and adaptive immunity. It consists of three pathways (alternative, classical, and lectin) that initiate either spontaneously (alternative) or in response to danger (all pathways). Complement leads to numerous outcomes detrimental to invaders, including direct killing by formation of the pore-forming membrane attack complex, recruitment of immune cells to sites of invasion, facilitation of phagocytosis, and enhancement of cellular immune responses. Pathogens must overcome the complement system to survive in the host. A common strategy used by pathogens to evade complement is hijacking host complement regulators. Complement regulators prevent attack of host cells and include a collection of membrane-bound and fluid phase proteins. Factor H (FH), a fluid phase complement regulatory protein, controls the alternative pathway (AP) both in the fluid phase of the human body and on cell surfaces. In order to prevent complement activation and amplification on host cells and tissues, FH recognizes host cell-specific polyanionic markers in combination with complement C3 fragments. FH suppresses AP complement-mediated attack by accelerating decay of convertases and by helping to inactivate C3 fragments on host cells. Pathogens, most of which do not have polyanionic markers, are not recognized by FH. Numerous pathogens, including certain bacteria, viruses, protozoa, helminths, and fungi, can recruit FH to protect themselves against host-mediated complement attack, using either specific receptors and/or molecular mimicry to appear more like a host cell. This review will explore pathogen complement evasion mechanisms involving FH recruitment with an emphasis on: (a) characterizing the structural properties and expression patterns of pathogen FH binding proteins, as well as other strategies used by pathogens to capture FH; (b) classifying domains of FH important in pathogen interaction; and (c) discussing existing and potential treatment strategies that target FH interactions with pathogens. Overall, many pathogens use FH to avoid complement attack and appreciating the commonalities across these diverse microorganisms deepens the understanding of complement in microbiology.
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Affiliation(s)
- Sara R Moore
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, United States
| | - Smrithi S Menon
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, United States
| | - Claudio Cortes
- Department of Foundational Medical Sciences, Oakland University William Beaumont School of Medicine, Rochester, MI, United States
| | - Viviana P Ferreira
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, United States
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14
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Sun Y, Xu B, Zhuge X, Tang F, Wang X, Gong Q, Chen R, Xue F, Dai J. Factor H Is Bound by Outer Membrane-Displayed Carbohydrate Metabolism Enzymes of Extraintestinal Pathogenic Escherichia coli and Contributes to Opsonophagocytosis Resistance in Bacteria. Front Cell Infect Microbiol 2021; 10:592906. [PMID: 33569353 PMCID: PMC7868385 DOI: 10.3389/fcimb.2020.592906] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 12/11/2020] [Indexed: 01/15/2023] Open
Abstract
Extraintestinal pathogenic Escherichia coli (ExPEC) causes bloodstream infections in humans and animals. Complement escape is a prerequisite for bacteria to survive in the bloodstream. Factor H (FH) is an important regulatory protein of the complement system. In this study, ExPEC was found to bind FH from serum. However, the mechanisms of ExPEC binding to FH and then resistance to complement-mediated attacks remain unclear. Here, a method that combined desthiobiotin pull-down and liquid chromatography-tandem mass spectrometry was used to identify the FH-binding membrane proteins of ExPEC. Seven identified proteins, which all were carbohydrate metabolic enzymes (CMEs), including acetate kinase, fructose-bisphosphate aldolase, fumarate reductase flavoprotein subunit, L-lactate dehydrogenase, dihydrolipoamide dehydrogenase, phosphoenolpyruvate synthase, and pyruvate dehydrogenase, were verified to recruit FH from serum using GST pull-down and ELISA plate binding assay. The ELISA plate binding assay determined that these seven proteins bind to FH in a dose-dependent manner. Magnetic beads coupled with any one of seven proteins significantly reduced the FH recruitment of ExPEC (p < 0.05) Subsequently, immunofluorescence, colony blotting, and Western blotting targeting outer membrane proteins determined that these seven CMEs were located on the outer membrane of ExPEC. Furthermore, the FH recruitment levels and C3b deposition levels on bacteria were significantly increased and decreased in an FH-concentration-dependent manner, respectively (p < 0.05). The FH recruitment significantly enhanced the ability of ExPEC to resist the opsonophagocytosis of human macrophage THP-1 in an FH-concentration-dependent manner (p < 0.05), which revealed a new mechanism for ExPEC to escape complement-mediated killing. The identification of novel outer membrane-displayed CMEs which played a role in the FH recruitment contributes to the elucidation of the molecular mechanism of ExPEC pathogenicity.
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Affiliation(s)
- Yu Sun
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.,Key Laboratory of Animal Bacteriology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, China
| | - Bin Xu
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.,Key Laboratory of Animal Bacteriology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, China.,National Research Center of Veterinary Biologicals Engineering and Technology, Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Xiangkai Zhuge
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.,Key Laboratory of Animal Bacteriology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, China.,Department of Nutrition and Food Hygiene, School of Public Health, Nantong University, Nantong, China
| | - Fang Tang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.,Key Laboratory of Animal Bacteriology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, China
| | - Xuhang Wang
- Key Laboratory of Animal Bacteriology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, China
| | - Qianwen Gong
- Key Laboratory of Animal Bacteriology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, China
| | - Rui Chen
- Key Laboratory of Animal Bacteriology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, China
| | - Feng Xue
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.,Key Laboratory of Animal Bacteriology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, China
| | - Jianjun Dai
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.,Key Laboratory of Animal Bacteriology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, China.,School of Life Science and Technology, China Pharmaceutical University, Nanjing, China
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15
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Maiti S, Howlader DR, Halder P, Bhaumik U, Dutta M, Dutta S, Koley H. Bivalent non-typhoidal Salmonella outer membrane vesicles immunized mice sera confer passive protection against gastroenteritis in a suckling mice model. Vaccine 2020; 39:380-393. [PMID: 33303233 DOI: 10.1016/j.vaccine.2020.11.040] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 11/06/2020] [Accepted: 11/15/2020] [Indexed: 11/28/2022]
Abstract
Invasive non-typhoidal Salmonella (iNTS) serovars, especially Salmonella Typhimurium (ST) and Salmonella Enteritidis (SE), cause gastroenteritis worldwide. Due to the emergence of multi-drug resistance in iNTS, a broad-spectrum vaccine is urgently needed for the prevention of iNTS infection. Currently, there is no effective licensed vaccine against iNTS available in the market. We have formulated an outer membrane vesicles (OMVs) based bivalent immunogen as a vaccine candidate to generate broad-spectrum protective immunity against both recently circulating prevalent ST and SE. We have isolated OMVs from ST and SE and formulated the immunogen by mixing both OMVs (1:1 ratio). Three doses of bivalent immunogen significantly induced humoral immune responses against lipopolysaccharides (LPSs) and outer membrane proteins (OMPs) as well as a cell-mediated immune response in adult mice. We also observed that proteins of OMVs act as an adjuvant for generation of high levels of anti-LPS antibodies through T cell activation. We then characterized the one-day old suckling mice model for both ST and SE mediated gastroenteritis and used the model for a passive protection study. In the passive protection study, we found the passive transfer of bivalent OMVs immunized sera significantly reduced ST and SE mediated colonization and gastroenteritis symptoms in the colon of suckling mice compared to non-immunized sera recipients. The overall study demonstrated that OMVs based bivalent vaccine could generate broad-spectrum immunity against prevalent iNTS mediated gastroenteritis. This study also established the suckling mice model as a suitable animal model for vaccine study against iNTS mediated gastroenteritis.
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Affiliation(s)
- Suhrid Maiti
- Division of Bacteriology, ICMR-National Institute of Cholera and Enteric Diseases, P-33 CIT Road, Scheme-XM, Beliaghata, Kolkata 700010, India
| | - Debaki Ranjan Howlader
- Division of Bacteriology, ICMR-National Institute of Cholera and Enteric Diseases, P-33 CIT Road, Scheme-XM, Beliaghata, Kolkata 700010, India
| | - Prolay Halder
- Division of Bacteriology, ICMR-National Institute of Cholera and Enteric Diseases, P-33 CIT Road, Scheme-XM, Beliaghata, Kolkata 700010, India
| | - Ushasi Bhaumik
- Division of Bacteriology, ICMR-National Institute of Cholera and Enteric Diseases, P-33 CIT Road, Scheme-XM, Beliaghata, Kolkata 700010, India
| | - Moumita Dutta
- Division of Electron Microscopy, ICMR-National Institute of Cholera and Enteric Diseases, P-33 CIT Road, Scheme-XM, Beliaghata, Kolkata 700010, India
| | - Shanta Dutta
- Division of Bacteriology, ICMR-National Institute of Cholera and Enteric Diseases, P-33 CIT Road, Scheme-XM, Beliaghata, Kolkata 700010, India
| | - Hemanta Koley
- Division of Bacteriology, ICMR-National Institute of Cholera and Enteric Diseases, P-33 CIT Road, Scheme-XM, Beliaghata, Kolkata 700010, India.
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16
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Krukonis ES, Thomson JJ. Complement evasion mechanisms of the systemic pathogens Yersiniae and Salmonellae. FEBS Lett 2020; 594:2598-2620. [DOI: 10.1002/1873-3468.13771] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 03/04/2020] [Accepted: 03/05/2020] [Indexed: 01/12/2023]
Affiliation(s)
- Eric S. Krukonis
- Division of Integrated Biomedical Sciences University of Detroit Mercy School of Dentistry Detroit MI USA
| | - Joshua J. Thomson
- Division of Integrated Biomedical Sciences University of Detroit Mercy School of Dentistry Detroit MI USA
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17
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Wu Y, Hu Q, Dehinwal R, Rakov AV, Grams N, Clemens EC, Hofmann J, Okeke IN, Schifferli DM. The Not so Good, the Bad and the Ugly: Differential Bacterial Adhesion and Invasion Mediated by Salmonella PagN Allelic Variants. Microorganisms 2020; 8:microorganisms8040489. [PMID: 32235448 PMCID: PMC7232170 DOI: 10.3390/microorganisms8040489] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 03/24/2020] [Accepted: 03/28/2020] [Indexed: 11/21/2022] Open
Abstract
While advances in genomic sequencing have highlighted significant strain variability between and within Salmonella serovars, only a few protein variants have been directly related to evolutionary adaptation for survival, such as host specificity or differential virulence. The current study investigated whether allelic variation of the Salmonella adhesin/invasin PagN influences bacterial interaction with their receptors. The Salmonella enterica, subspecies enterica serovar Typhi (S. Typhi) allelic variant of PagN was found to bind significantly better to different enterocytes as well as to the extracellular matrix protein laminin than did the major Salmonella enterica, subspecies enterica serovar Typhimurium (S. Typhimurium) allele. The two alleles differed at amino acid residues 49 and 109 in two of the four predicted PagN surface loops, and residue substitution analysis revealed that a glutamic acid at residue 49 increased the adhesive and invasive properties of S. Typhi PagN. PagN sequence comparisons from 542 Salmonella strains for six representative S. enterica serovars and S. diarizonae further supported the role of glutamic acid at residues 49 and 109 in optimizing adhesion to cells and laminin, as well as for cell invasion. In summary, this study characterized unique residues in allelic variants of a virulence factor that participates in the colonization and invasive properties of different Salmonella stains, subspecies and serovars.
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Affiliation(s)
- Yanping Wu
- Department of Pathobiology, University of Pennsylvania, School of Veterinary Medicine, Philadelphia, PA 19104, USA; (Y.W.); (R.D.); (A.V.R.); (N.G.)
- College of Animal Science and Technology, College of Veterinary Medicine, Zhejiang Agriculture and Forestry University, Hangzhou 311300, China
| | - Qiaoyun Hu
- Department of Pathobiology, University of Pennsylvania, School of Veterinary Medicine, Philadelphia, PA 19104, USA; (Y.W.); (R.D.); (A.V.R.); (N.G.)
| | - Ruchika Dehinwal
- Department of Pathobiology, University of Pennsylvania, School of Veterinary Medicine, Philadelphia, PA 19104, USA; (Y.W.); (R.D.); (A.V.R.); (N.G.)
| | - Alexey V. Rakov
- Department of Pathobiology, University of Pennsylvania, School of Veterinary Medicine, Philadelphia, PA 19104, USA; (Y.W.); (R.D.); (A.V.R.); (N.G.)
| | - Nicholas Grams
- Department of Pathobiology, University of Pennsylvania, School of Veterinary Medicine, Philadelphia, PA 19104, USA; (Y.W.); (R.D.); (A.V.R.); (N.G.)
| | - Erin C. Clemens
- Department of Biology, Haverford College, Haverford, PA 19041, USA; (E.C.C.); (J.H.); (I.N.O.)
| | - Jennifer Hofmann
- Department of Biology, Haverford College, Haverford, PA 19041, USA; (E.C.C.); (J.H.); (I.N.O.)
| | - Iruka N. Okeke
- Department of Biology, Haverford College, Haverford, PA 19041, USA; (E.C.C.); (J.H.); (I.N.O.)
- Department of Pharmaceutical Microbiology, Faculty of Pharmacy, University of Ibadan, Ibadan 200284, Oyo State, Nigeria
| | - Dieter M. Schifferli
- Department of Pathobiology, University of Pennsylvania, School of Veterinary Medicine, Philadelphia, PA 19104, USA; (Y.W.); (R.D.); (A.V.R.); (N.G.)
- Correspondence:
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18
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Cheng ZX, Guo C, Chen ZG, Yang TC, Zhang JY, Wang J, Zhu JX, Li D, Zhang TT, Li H, Peng B, Peng XX. Glycine, serine and threonine metabolism confounds efficacy of complement-mediated killing. Nat Commun 2019; 10:3325. [PMID: 31346171 PMCID: PMC6658569 DOI: 10.1038/s41467-019-11129-5] [Citation(s) in RCA: 105] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2018] [Accepted: 06/24/2019] [Indexed: 11/28/2022] Open
Abstract
Serum resistance is a poorly understood but common trait of some difficult-to-treat pathogenic strains of bacteria. Here, we report that glycine, serine and threonine catabolic pathway is down-regulated in serum-resistant Escherichia coli, whereas exogenous glycine reverts the serum resistance and effectively potentiates serum to eliminate clinically-relevant bacterial pathogens in vitro and in vivo. We find that exogenous glycine increases the formation of membrane attack complex on bacterial membrane through two previously unrecognized regulations: 1) glycine negatively and positively regulates metabolic flux to purine biosynthesis and Krebs cycle, respectively. 2) α-Ketoglutarate inhibits adenosine triphosphate synthase, which in together promote the formation of cAMP/CRP regulon to increase the expression of complement-binding proteins HtrE, NfrA, and YhcD. The results could lead to effective strategies for managing the infection with serum-resistant bacteria, an especially valuable approach for treating individuals with weak acquired immunity but a normal complement system. Serum-resistant bacteria can escape complement killing in the bloodstream. Here, using metabolomics and metabolite perturbations, the authors describe an altered metabolic state in serum-resistant Escherichia coli and show that exogenous glycine potentiates elimination of pathogenic bacteria in vivo.
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Affiliation(s)
- Zhi-Xue Cheng
- Center for Proteomics and Metabolomics, State Key Laboratory of Bio-Control, School of Life Sciences, Sun Yat-sen University, University City, Guangzhou, 510006, People's Republic of China.,Laboratory for Marine Biology and Biotechnology, Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China
| | - Chang Guo
- Center for Proteomics and Metabolomics, State Key Laboratory of Bio-Control, School of Life Sciences, Sun Yat-sen University, University City, Guangzhou, 510006, People's Republic of China
| | - Zhuang-Gui Chen
- Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510630, People's Republic of China
| | - Tian-Ci Yang
- Zhongshan Hospital of Xiamen University, Xiamen, 361004, People's Republic of China
| | - Jian-Ying Zhang
- Henan Academy of Medical and Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, Henan, 450052, People's Republic of China
| | - Jie Wang
- Center for Proteomics and Metabolomics, State Key Laboratory of Bio-Control, School of Life Sciences, Sun Yat-sen University, University City, Guangzhou, 510006, People's Republic of China
| | - Jia-Xin Zhu
- Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510630, People's Republic of China
| | - Dan Li
- Center for Proteomics and Metabolomics, State Key Laboratory of Bio-Control, School of Life Sciences, Sun Yat-sen University, University City, Guangzhou, 510006, People's Republic of China
| | - Tian-Tuo Zhang
- Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510630, People's Republic of China.
| | - Hui Li
- Center for Proteomics and Metabolomics, State Key Laboratory of Bio-Control, School of Life Sciences, Sun Yat-sen University, University City, Guangzhou, 510006, People's Republic of China. .,Laboratory for Marine Biology and Biotechnology, Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China. .,Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, 519000, China.
| | - Bo Peng
- Center for Proteomics and Metabolomics, State Key Laboratory of Bio-Control, School of Life Sciences, Sun Yat-sen University, University City, Guangzhou, 510006, People's Republic of China. .,Laboratory for Marine Biology and Biotechnology, Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China. .,Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, 519000, China.
| | - Xuan-Xian Peng
- Center for Proteomics and Metabolomics, State Key Laboratory of Bio-Control, School of Life Sciences, Sun Yat-sen University, University City, Guangzhou, 510006, People's Republic of China. .,Laboratory for Marine Biology and Biotechnology, Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China. .,Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, 519000, China.
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19
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Futoma-Kołoch B, Bugla-Płoskońska G, Dudek B, Dorotkiewicz-Jach A, Drulis-Kawa Z, Gamian A. Outer Membrane Proteins of Salmonella as Potential Markers of Resistance to Serum, Antibiotics and Biocides. Curr Med Chem 2019; 26:1960-1978. [PMID: 30378478 DOI: 10.2174/0929867325666181031130851] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 07/13/2018] [Accepted: 08/14/2018] [Indexed: 01/05/2023]
Abstract
Salmonellosis continues to be a significant worldwide health problem. Despite rapid progress in identifying mechanisms of Salmonella virulence and resistance to chemicals, our knowledge of these mechanisms remains limited. Furthermore, it appears that the resistance to antibiotics can be amplified by ubiquitous usage of the disinfectants (biocides), both by industry and by ordinary households. Salmonella, as other Gram-negative bacteria possess outer membrane proteins (OMPs), which participate in maintaining cell integrity, adapting to environment, and interacting with infected host. Moreover, the OMPs may also contribute to resistance to antibacterials. This review summarizes the role of OMPs in Salmonella serum resistance, antibiotics resistance and cross-resistance to biocides. Although collected data do not allow to assign OMPs as markers of the Salmonella susceptibility to the above-mentioned factors, some of these proteins retain a dominant presence in certain types of resistance.
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Affiliation(s)
- Bożena Futoma-Kołoch
- Department of Microbiology, Institute of Genetics and Microbiology, University of Wrocław, Przybyszewskiego 63-77, 51-148 Wroclaw, Poland
| | - Gabriela Bugla-Płoskońska
- Department of Microbiology, Institute of Genetics and Microbiology, University of Wrocław, Przybyszewskiego 63-77, 51-148 Wroclaw, Poland
| | - Bartłomiej Dudek
- Department of Microbiology, Institute of Genetics and Microbiology, University of Wrocław, Przybyszewskiego 63-77, 51-148 Wroclaw, Poland
| | - Agata Dorotkiewicz-Jach
- Department of Pathogen Biology and Immunology, Institute of Genetics and Microbiology, University of Wrocław, Przybyszewskiego 63-77, 51-148 Wroclaw, Poland
| | - Zuzanna Drulis-Kawa
- Department of Pathogen Biology and Immunology, Institute of Genetics and Microbiology, University of Wrocław, Przybyszewskiego 63-77, 51-148 Wroclaw, Poland
| | - Andrzej Gamian
- Department of Immunology of Infectious Diseases, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Rudolfa Weigla 12, 53-114 Wroclaw, Poland
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20
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Das S, Chowdhury R, Pal A, Okamoto K, Das S. Salmonella Typhi outer membrane protein STIV is a potential candidate for vaccine development against typhoid and paratyphoid fever. Immunobiology 2019; 224:371-382. [DOI: 10.1016/j.imbio.2019.02.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 02/09/2019] [Accepted: 02/26/2019] [Indexed: 01/07/2023]
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21
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Thomson JJ, Plecha SC, Krukonis ES. Ail provides multiple mechanisms of serum resistance to Yersinia pestis. Mol Microbiol 2018; 111:82-95. [PMID: 30260060 DOI: 10.1111/mmi.14140] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/21/2018] [Indexed: 02/06/2023]
Abstract
Ail, a multifunctional outer membrane protein of Yersinia pestis, confers cell binding, Yop delivery and serum resistance activities. Resistance to complement proteins in serum is critical for the survival of Y. pestis during the septicemic stage of plague infections. Bacteria employ a variety of tactics to evade the complement system, including recruitment of complement regulatory factors, such as factor H, C4b-binding protein (C4BP) and vitronectin (Vn). Y. pestis Ail interacts with the regulatory factors Vn and C4BP, and Ail homologs from Y. enterocolitica and Y. pseudotuberculosis recruit factor H. Using co-sedimentation assays, we demonstrate that two surface-exposed amino acids, F80 and F130, are required for the interaction of Y. pestis Ail with Vn, factor H and C4BP. However, although Ail-F80A/F130A fails to interact with these complement regulatory proteins, it still confers 10,000-fold more serum resistance than a Δail strain and prevents C9 polymerization, potentially by directly interfering with MAC assembly. Using site-directed mutagenesis, we further defined this additional mechanism of complement evasion conferred by Ail. Finally, we find that at Y. pestis concentrations reflective of early-stage septicemic plague, Ail weakly recruits Vn and fails to recruit factor H, suggesting that this alternative mechanism of serum resistance may be essential during plague infection.
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Affiliation(s)
- Joshua J Thomson
- Division of Integrated Biomedical Sciences, University of Detroit Mercy School of Dentistry, Detroit, MI, USA
| | - Sarah C Plecha
- Division of Integrated Biomedical Sciences, University of Detroit Mercy School of Dentistry, Detroit, MI, USA
| | - Eric S Krukonis
- Division of Integrated Biomedical Sciences, University of Detroit Mercy School of Dentistry, Detroit, MI, USA.,Department of Immunology, Microbiology, and Biochemistry, Wayne State University School of Medicine, Detroit, MI, USA.,Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
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22
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Cheng ZX, Gong QY, Wang Z, Chen ZG, Ye JZ, Li J, Wang J, Yang MJ, Ling XP, Peng B. Edwardsiella tarda Tunes Tricarboxylic Acid Cycle to Evade Complement-Mediated Killing. Front Immunol 2017; 8:1706. [PMID: 29270172 PMCID: PMC5725468 DOI: 10.3389/fimmu.2017.01706] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 11/20/2017] [Indexed: 01/12/2023] Open
Abstract
Evasion of complement-mediated killing is a common phenotype for many different types of pathogens, but the mechanism is still poorly understood. Most of the clinic isolates of Edwardsiella tarda, an important pathogen infecting both of human and fish, are commonly found serum-resistant. To explore the potential mechanisms, we applied gas chromatography-mass spectrometry (GC-MS)-based metabolomics approaches to profile the metabolomes of E. tarda EIB202 in the presence or absence of serum stress. We found that tricarboxylic acid (TCA) cycle was greatly enhanced in the presence of serum. The quantitative real-time PCR (qRT-PCR) and enzyme activity assays validated this result. Furthermore, exogenous succinate that promotes the TCA cycle increased serum resistance, while TCA cycle inhibitors (bromopyruvate and propanedioic acid) that inhibit TCA cycle, attenuated serum resistance. Moreover, the enhanced TCA cycle increased membrane potential, thus decreased the formation of membrane attack complex at cell surface, resulting serum resistance. These evidences suggested a previously unknown membrane potential-dependent mechanism of serum resistance. Therefore, our findings reveal that pathogen mounts a metabolic trick to cope with the serum complement-mediated killing.
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Affiliation(s)
- Zhi-Xue Cheng
- Center for Proteomics and Metabolomics, State Key Laboratory of Bio-Control, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Qi-Yang Gong
- Center for Proteomics and Metabolomics, State Key Laboratory of Bio-Control, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Zhe Wang
- Center for Proteomics and Metabolomics, State Key Laboratory of Bio-Control, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Zhuang-Gui Chen
- Pediatric Intensive Care Unit, Department of Pediatrics, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Jin-Zhou Ye
- Center for Proteomics and Metabolomics, State Key Laboratory of Bio-Control, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Jun Li
- Center for Proteomics and Metabolomics, State Key Laboratory of Bio-Control, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Jie Wang
- Center for Proteomics and Metabolomics, State Key Laboratory of Bio-Control, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Man-Jun Yang
- Center for Proteomics and Metabolomics, State Key Laboratory of Bio-Control, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Xiao-Peng Ling
- Center for Proteomics and Metabolomics, State Key Laboratory of Bio-Control, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Bo Peng
- Center for Proteomics and Metabolomics, State Key Laboratory of Bio-Control, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
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23
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Dudek B, Krzyżewska E, Kapczyńska K, Rybka J, Pawlak A, Korzekwa K, Klausa E, Bugla-Płoskońska G. Proteomic Analysis of Outer Membrane Proteins from Salmonella Enteritidis Strains with Different Sensitivity to Human Serum. PLoS One 2016; 11:e0164069. [PMID: 27695090 PMCID: PMC5047454 DOI: 10.1371/journal.pone.0164069] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 09/19/2016] [Indexed: 01/16/2023] Open
Abstract
Differential analysis of outer membrane composition of S. Enteritidis strains, resistant to 50% normal human serum (NHS) was performed in order to find factors influencing the resistance to higher concentrations of NHS. Ten S. Enteritidis clinical strains, resistant to 50% NHS, all producing very long lipopolysaccharide, were subjected to the challenge of 75% NHS. Five extreme strains: two resistant and three sensitive to 75% NHS, were chosen for the further analysis of outer membrane proteins composition. Substantial differences were found in the levels of particular outer membrane proteins between resistant and sensitive strains, i.e. outer membrane protease E (PgtE) was present mainly in resistant strains, while sensitive strains possessed a high level of flagellar hook-associated protein 2 (FliD) and significantly higher levels of outer membrane protein A (OmpA).
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Affiliation(s)
- Bartłomiej Dudek
- Department of Microbiology, Institute of Genetics and Microbiology, Faculty of Biological Sciences, University of Wroclaw, Wroclaw, Poland
| | - Eva Krzyżewska
- Department of Immunology of Infectious Diseases, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wroclaw, Poland
| | - Katarzyna Kapczyńska
- Department of Immunology of Infectious Diseases, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wroclaw, Poland
| | - Jacek Rybka
- Department of Immunology of Infectious Diseases, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wroclaw, Poland
| | - Aleksandra Pawlak
- Department of Microbiology, Institute of Genetics and Microbiology, Faculty of Biological Sciences, University of Wroclaw, Wroclaw, Poland
| | - Kamila Korzekwa
- Department of Microbiology, Institute of Genetics and Microbiology, Faculty of Biological Sciences, University of Wroclaw, Wroclaw, Poland
- Dialab Laboratory, Wroclaw, Poland
| | - Elżbieta Klausa
- Regional Centre of Transfusion Medicine and Blood Bank, Wroclaw, Poland
| | - Gabriela Bugla-Płoskońska
- Department of Microbiology, Institute of Genetics and Microbiology, Faculty of Biological Sciences, University of Wroclaw, Wroclaw, Poland
- * E-mail:
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24
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Li W, Wen L, Li C, Chen R, Ye Z, Zhao J, Pan J. Contribution of the outer membrane protein OmpW in Escherichia coli to complement resistance from binding to factor H. Microb Pathog 2016; 98:57-62. [PMID: 27364548 DOI: 10.1016/j.micpath.2016.06.024] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Revised: 06/14/2016] [Accepted: 06/24/2016] [Indexed: 01/20/2023]
Abstract
The serum complement system is essential for innate immune defense against invading pathogenic bacteria. Some of the 8-stranded β-barrel outer membrane proteins confer bacterial resistance to the innate host immunity. We have previously demonstrated that OmpW, also an 8-stranded β-barrel protein that was identified a decade ago, protects bacteria against host phagocytosis. In this study, we investigated the complement resistance of OmpW. Our results indicate that the upregulation of OmpW is associated with increased survival when bacteria are exposed to normal human sera (NHS). Mutant bacteria lacking OmpW in NHS exhibited significantly lower survival rates in comparison to wild-type and ompW complemented bacteria. Furthermore, the bacterial survival significantly decreased in NHS that was supplemented with EGTA-Mg(2+) compared to that in NHS supplemented with EDTA. These results suggest that OmpW confer resistance to alternative complement pathway-mediated killing. Moreover, the binding of OmpW to factor H, a major inhibitor of alternative pathway, was found, indicating that OmpW recruitment of factor H is a mechanism for bacterial evasion of complement attack.
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Affiliation(s)
- Weiyan Li
- School of Life Sciences, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Liangyou Wen
- School of Life Sciences, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Chuchu Li
- School of Life Sciences, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Ran Chen
- School of Life Sciences, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Zhicang Ye
- School of Life Sciences, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Jie Zhao
- School of Life Sciences, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Jianyi Pan
- School of Life Sciences, Zhejiang Sci-Tech University, Hangzhou 310018, China.
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25
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Ram S, Shaughnessy J, DeOliveira RB, Lewis LA, Gulati S, Rice PA. Utilizing complement evasion strategies to design complement-based antibacterial immunotherapeutics: Lessons from the pathogenic Neisseriae. Immunobiology 2016; 221:1110-23. [PMID: 27297292 DOI: 10.1016/j.imbio.2016.05.016] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 05/27/2016] [Indexed: 12/30/2022]
Abstract
Novel therapies are urgently needed to combat the global threat of multidrug-resistant pathogens. Complement forms an important arm of innate defenses against infections. In physiological conditions, complement activation is tightly controlled by soluble and membrane-associated complement inhibitors, but must be selectively activated on invading pathogens to facilitate microbial clearance. Many pathogens, including Neisseria gonorrhoeae and N. meningitidis, express glycans, including N-acetylneuraminic acid (Neu5Ac), that mimic host structures to evade host immunity. Neu5Ac is a negatively charged 9-cabon sugar that inhibits complement, in part by enhancing binding of the complement inhibitor factor H (FH) through C-terminal domains (19 and 20) on FH. Other microbes also bind FH, in most instances through FH domains 6 and 7 or 18-20. Here we describe two strategies to target complement activation on Neisseriae. First, microbial binding domains of FH were fused to IgG Fc to create FH18-20/Fc (binds gonococci) and FH6,7/Fc (binds meningococci). A point mutation in FH domain 19 eliminated hemolysis caused by unmodified FH18-20, but retained binding to gonococci. FH18-20/Fc and FH6,7/Fc mediated complement-dependent killing in vitro and showed efficacy in animal models of gonorrhea and meningococcal bacteremia, respectively. The second strategy utilized CMP-nonulosonate (CMP-NulO) analogs of sialic acid that were incorporated into LOS and prevented complement inhibition by physiologic CMP-Neu5Ac and resulted in attenuated gonococcal infection in mice. While studies to establish the safety of these agents are needed, enhancing complement activation on microbes may represent a promising strategy to treat antimicrobial resistant organisms.
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Affiliation(s)
- Sanjay Ram
- Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, MA 01605, USA.
| | - Jutamas Shaughnessy
- Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Rosane B DeOliveira
- Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Lisa A Lewis
- Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Sunita Gulati
- Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Peter A Rice
- Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, MA 01605, USA
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26
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Futoma-Kołoch B, Godlewska U, Guz-Regner K, Dorotkiewicz-Jach A, Klausa E, Rybka J, Bugla-Płoskońska G. Presumable role of outer membrane proteins of Salmonella containing sialylated lipopolysaccharides serovar Ngozi, sv. Isaszeg and subspecies arizonae in determining susceptibility to human serum. Gut Pathog 2015; 7:18. [PMID: 26185527 PMCID: PMC4504086 DOI: 10.1186/s13099-015-0066-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 07/07/2015] [Indexed: 01/15/2023] Open
Abstract
Background The O48 group comprises Salmonella bacteria containing sialic acid in the lipopolysaccharide (LPS). Bacteria with sialylated surface structures are described as pathogens that avoid immunological response of the host by making similar their surface antigens to the host’s tissues (molecular mimicry). It is known that the smooth-type LPS of Salmonella enterica and outer membrane proteins (OMP) PgtE, PagC and Rck mediate serum resistant phenotype by affecting complement system (C). The aim of this study was to investigate C3 component activation by Salmonella O48 LPS and OMP. Findings In the present study, we examined C3 component deposition on the three Salmonella O48 strains: S. enterica subspecies enterica serovar Ngozi, S. enterica subsp. enterica sv. Isaszeg, and S.enterica subsp. arizonae containing sialic acid in the O-specific part of LPS. The greatest C3 deposition occurred on Salmonella sv. Isaszeg cells (p < 0.005) as well as on their LPS (low content of sialic acid in LPS) (p < 0.05) after 45 min of incubation in 50% human serum. Weaker C3 deposition ratio on the Salmonella sv. Ngozi (high content of sialic acid in LPS) and Salmonella subsp. arizonae (high content of sialic acid in LPS) cells correlated with the lower C3 activation on their LPS. Immunoblotting revealed that OMP isolated from the tested strains also bound C3 protein fragments. Conclusions We suggest that activation of C3 serum protein is dependent on the sialic acid contents in the LPS as well as on the presence of OMP in the range of molecular masses of 35–48 kDa.
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Affiliation(s)
- Bożena Futoma-Kołoch
- Department of Microbiology, Institute of Genetics and Microbiology, University of Wrocław, Przybyszewskiego 63-77, 51-148 Wrocław, Poland
| | - Urszula Godlewska
- Department of Microbiology, Institute of Genetics and Microbiology, University of Wrocław, Przybyszewskiego 63-77, 51-148 Wrocław, Poland
| | - Katarzyna Guz-Regner
- Department of Microbiology, Institute of Genetics and Microbiology, University of Wrocław, Przybyszewskiego 63-77, 51-148 Wrocław, Poland
| | - Agata Dorotkiewicz-Jach
- Department of Pathogens' Biology and Immunology, Institute of Genetics and Microbiology, University of Wrocław, Przybyszewskiego 63-77, 51-148 Wrocław, Poland
| | - Elżbieta Klausa
- Regional Centre of Transfusion Medicine and Blood Bank, Czerwonego Krzyża 5, 50-345 Wrocław, Poland
| | - Jacek Rybka
- Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Weigla 12, 53-114 Wrocław, Poland
| | - Gabriela Bugla-Płoskońska
- Department of Microbiology, Institute of Genetics and Microbiology, University of Wrocław, Przybyszewskiego 63-77, 51-148 Wrocław, Poland
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27
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Riva R, Korhonen TK, Meri S. The outer membrane protease PgtE of Salmonella enterica interferes with the alternative complement pathway by cleaving factors B and H. Front Microbiol 2015; 6:63. [PMID: 25705210 PMCID: PMC4319491 DOI: 10.3389/fmicb.2015.00063] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Accepted: 01/18/2015] [Indexed: 11/21/2022] Open
Abstract
The virulence factor PgtE is an outer membrane protease (omptin) of the zoonotic pathogen Salmonella enterica that causes diseases ranging from gastroenteritis to severe enteric fever. It is surface exposed in bacteria that have a short-chain, i.e., rough LPS, as observed e.g., in bacteria residing inside macrophages or just emerging from them. We investigated whether PgtE cleaves the complement factors B (B) and H (H), key proteins controlling formation and inactivation of the complement protein C3b and thereby the activity of the complement system. S. enterica serovar Typhimurium or omptin-expressing recombinant E. coli bacteria were incubated with purified human complement proteins or recombinant H fragments. PgtE cleaved both B and H, whereas its close homolog Pla of Yersinia pestis cleaved only H. H was cleaved at both N- and C-termini, while the central region resisted proteolysis. Because of multiple effects of PgtE on complement components (cleavage of C3, C3b, B, and H) we assessed its effect on the opsonophagocytosis of Salmonella. In human serum, C3 cleavage was dependent on proteolytically active PgtE. Human neutrophils interacted less with serum-opsonized FITC-stained S. enterica 14028R than with the isogenic ΔpgtE strain, as analyzed by flow cytometry. In conclusion, cleavage of B and H by PgtE, together with C3 cleavage, affects the C3-mediated recognition of S. enterica by human neutrophils, thus thwarting the immune protection against Salmonella.
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Affiliation(s)
- Rauna Riva
- Immunobiology Research Program, Research Program Unit, University of HelsinkiHelsinki, Finland
- Department of Bacteriology and Immunology, Haartman Institute, University of HelsinkiHelsinki, Finland
| | - Timo K. Korhonen
- General Microbiology, Department of Biosciences, University of HelsinkiHelsinki, Finland
| | - Seppo Meri
- Immunobiology Research Program, Research Program Unit, University of HelsinkiHelsinki, Finland
- Department of Bacteriology and Immunology, Haartman Institute, University of HelsinkiHelsinki, Finland
- HUSLAB, Hospital District of Helsinki and UusimaaHelsinki, Finland
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28
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Mohan S, Hertweck C, Dudda A, Hammerschmidt S, Skerka C, Hallström T, Zipfel PF. Tuf of Streptococcus pneumoniae is a surface displayed human complement regulator binding protein. Mol Immunol 2014; 62:249-64. [PMID: 25046156 DOI: 10.1016/j.molimm.2014.06.029] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Revised: 06/21/2014] [Accepted: 06/23/2014] [Indexed: 11/15/2022]
Abstract
Streptococcus pneumoniae is a Gram-positive bacterium, causing acute sinusitis, otitis media, and severe diseases such as pneumonia, bacteraemia, meningitis and sepsis. Here we identify elongation factor Tu (Tuf) as a new Factor H binding protein of S. pneumoniae. The surface protein PspC which also binds a series of other human immune inhibitors, was the first identified pneumococcal Factor H binding protein of S. pneumoniae. Pneumococcal Tuf, a 55 kDa pneumococcal moonlighting protein which is displayed on the surface of pneumococci, is also located in the cytoplasm and is detected in the culture supernatant. Tuf binds the human complement inhibitors Factor H, FHL-1, CFHR1 and also the proenzyme plasminogen. Factor H and FHL-1 bound to Tuf, retain their complement regulatory activities. Similarly, plasminogen bound to Tuf was accessible for the activator uPA and activated plasmin cleaved the synthetic chromogenic substrate S-2251 as well as the natural substrates fibrinogen and the complement proteins C3 and C3b. Taken together, Tuf of S. pneumoniae is a new multi-functional bacterial virulence factor that helps the pathogen in complement escape and likely also in ECM degradation.
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Affiliation(s)
- Sarbani Mohan
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Hans-Knöll-Institute, Jena, Germany
| | - Christian Hertweck
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology, Hans-Knöll-Institute, Jena, Germany
| | - Antje Dudda
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Hans-Knöll-Institute, Jena, Germany
| | - Sven Hammerschmidt
- Department Genetics of Microorganisms, Interfaculty Institute for Genetics and Functional Genomics, Ernst Moritz Arndt University, Greifswald, Germany
| | - Christine Skerka
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Hans-Knöll-Institute, Jena, Germany
| | - Teresia Hallström
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Hans-Knöll-Institute, Jena, Germany
| | - Peter F Zipfel
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Hans-Knöll-Institute, Jena, Germany; Faculty of Biology, Friedrich Schiller University, Jena, Germany.
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29
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Ho DK, Skurnik M, Blom AM, Meri S. Yersinia pestis Ail recruitment of C4b-binding protein leads to factor I-mediated inactivation of covalently and noncovalently bound C4b. Eur J Immunol 2014; 44:742-51. [PMID: 24760758 DOI: 10.1002/eji.201343552] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 10/10/2013] [Accepted: 11/25/2013] [Indexed: 12/14/2022]
Abstract
The outer membrane protein Ail of Yersinia pestis mediates several virulence functions, including serum resistance. Here, we demonstrate that Ail binds C4b-binding protein (C4BP), the primary fluid-phase regulator of the classical and lectin pathways. Non-covalent binding of C4 and C4b to Ail was also observed. C4BP bound to Ail can act as a cofactor to the serine protease factor I (fI) in the cleavage of fluid-phase C4b. Employing a panel of C4BP alpha-chain mutants, we observed that the absence of complement control protein domain 6 and 8 reduced binding to Ail. Immunoblot analysis of normal human serum (NHS)-treated bacteria revealed minimal C4b alpha'-chain complexes with bacterial outer membrane targets. Addition of the anti-C4BP monoclonal antibody MK104 to NHS restored C4b-alpha' chain target complexes, suggesting that C4b binds covalently to targets on the Y. pestis surface. C4b bound to Ail noncovalently was also cleaved in a C4BP and fI-dependent manner, leaving the C4c fragment bound to Ail. MK104 also prevented the cleavage of noncovalently bound C4b. Collectively, these data suggest that when C4BP is bound to Ail, fI can cleave and inactivate C4b that has bound covalently to bacterial surface structures as well as C4b bound noncovalently to Ail.
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Affiliation(s)
- Derek K Ho
- Immunobiology Program, Department of Bacteriology and Immunology, Haartman Institute, University of Helsinki, Helsinki, Finland
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30
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Riley SP, Patterson JL, Nava S, Martinez JJ. Pathogenic Rickettsia species acquire vitronectin from human serum to promote resistance to complement-mediated killing. Cell Microbiol 2013; 16:849-61. [PMID: 24286496 DOI: 10.1111/cmi.12243] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Revised: 10/30/2013] [Accepted: 11/15/2013] [Indexed: 01/01/2023]
Abstract
Bacteria of the genus Rickettsia are transmitted from arthropod vectors and primarily infect cells of the mammalian endothelial system. Throughout this infectious cycle, the bacteria are exposed to the deleterious effects of serum complement. Using Rickettsia conorii, the etiologic agent of Mediterranean spotted fever (MSF), as a model rickettsial species, we have previously demonstrated that this class of pathogen interacts with human factor H to mediate partial survival in human serum. Herein, we demonstrate that R. conorii also interacts with the terminal complement complex inhibitor vitronectin (Vn). We further demonstrate that an evolutionarily conserved rickettsial antigen, Adr1/RC1281, interacts with human vitronectin and is sufficient to mediate resistance to serum killing when expressed at the outer-membrane of serum sensitive Escherichia coli. Adr1 is an integral outer-membrane protein whose structure is predicted to contain eight membrane-embedded β-strands and four 'loop' regions that are exposed to extracellular milieu. Site-directed mutagenesis of Adr1 revealed that at least two predicted 'loop' regions are required to mediate resistance to complement-mediatedkilling and vitronectin acquisition. These results demonstrate that rickettsial species have evolved multiple mechanisms to evade complement deposition and that evasion of killing in serum is an evolutionarily conserved virulence attribute for this genus of obligate intracellular pathogens.
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Affiliation(s)
- Sean P Riley
- Department of Microbiology, University of Chicago, Chicago, IL, 60637, USA; Howard T. Ricketts Laboratory, Argonne, IL, 60439, USA; Vector-Borne Diseases Laboratories, Department of Pathobiological Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, LA, 70803, USA
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31
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Bhattacharjee A, Oeemig JS, Kolodziejczyk R, Meri T, Kajander T, Lehtinen MJ, Iwaï H, Jokiranta TS, Goldman A. Structural basis for complement evasion by Lyme disease pathogen Borrelia burgdorferi. J Biol Chem 2013; 288:18685-95. [PMID: 23658013 DOI: 10.1074/jbc.m113.459040] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Borrelia burgdorferi spirochetes that cause Lyme borreliosis survive for a long time in human serum because they successfully evade the complement system, an important arm of innate immunity. The outer surface protein E (OspE) of B. burgdorferi is needed for this because it recruits complement regulator factor H (FH) onto the bacterial surface to evade complement-mediated cell lysis. To understand this process at the molecular level, we used a structural approach. First, we solved the solution structure of OspE by NMR, revealing a fold that has not been seen before in proteins involved in complement regulation. Next, we solved the x-ray structure of the complex between OspE and the FH C-terminal domains 19 and 20 (FH19-20) at 2.83 Å resolution. The structure shows that OspE binds FH19-20 in a way similar to, but not identical with, that used by endothelial cells to bind FH via glycosaminoglycans. The observed interaction of OspE with FH19-20 allows the full function of FH in down-regulation of complement activation on the bacteria. This reveals the molecular basis for how B. burgdorferi evades innate immunity and suggests how OspE could be used as a potential vaccine antigen.
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Affiliation(s)
- Arnab Bhattacharjee
- Haartman Institute, Department of Bacteriology and Immunology, and Research Programs Unit, Immunobiology, University of Helsinki, FIN-00014 Helsinki, Finland
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32
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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: 52] [Impact Index Per Article: 4.7] [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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33
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Goh YS, MacLennan CA. Invasive African nontyphoidal Salmonella requires high levels of complement for cell-free antibody-dependent killing. J Immunol Methods 2012; 387:121-9. [PMID: 23085530 DOI: 10.1016/j.jim.2012.10.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2012] [Revised: 10/09/2012] [Accepted: 10/11/2012] [Indexed: 11/18/2022]
Abstract
Nontyphoidal isolates of Salmonella (NTS), particularly Salmonella Typhimurium, are a major cause of invasive bacteremia in Africa. Despite this, no vaccine against NTS is currently available for use in humans. If a NTS vaccine is to be developed in a timely manner, there is a need to develop assays to assess its in vivo efficacy. Assessment of potential efficacy of candidate vaccines in preclinical models is important for proof-of-concept and reduces attrition of vaccines in clinical trials. Serum bactericidal assays (SBA) are often used to assess the functional activity of vaccine-induced antibody responses targeted against Gram-negative bacteria with results given as the maximum dilution of serum that can effect bacterial killing. Previously we have found evidence for a protective role for antibody-induced complement-mediated killing of NTS in African children using an undiluted whole serum SBA. However, endogenous complement in diluted human sera is limiting and insufficient to effect bactericidal activity against S. Typhimurium beyond two two-fold dilutions. In the current study, we examined the requirements for SBA against NTS using baby rabbit serum (BRS) as an exogenous source of complement. We found that the amount of complement required for antibody-mediated bactericidal activity is much higher for the invasive African S. Typhimurium isolate D23580, compared with the laboratory S. Typhimurium LT2 and Salmonella Paratyphi A CVD1901. While 20% BRS was sufficient to kill LT2 and CVD1901, 75% BRS was needed to kill D23580. Our findings demonstrate that one concentration of exogenous complement is not suitable for SBA against all Salmonella isolates. To develop SBA to assess the in vivo efficacy of Salmonella vaccines, it is necessary to optimize the assay for the Salmonella isolates against which the vaccine is targeted.
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Affiliation(s)
- Yun Shan Goh
- Novartis Vaccines Institute for Global Health, Via Fiorentina 1, 53100 Siena, Italy
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Hallström T, Mörgelin M, Barthel D, Raguse M, Kunert A, Hoffmann R, Skerka C, Zipfel PF. Dihydrolipoamide Dehydrogenase of Pseudomonas aeruginosa Is a Surface-Exposed Immune Evasion Protein That Binds Three Members of the Factor H Family and Plasminogen. THE JOURNAL OF IMMUNOLOGY 2012; 189:4939-50. [DOI: 10.4049/jimmunol.1200386] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Ho DK, Riva R, Skurnik M, Meri S. TheYersinia pseudotuberculosisOuter Membrane Protein Ail Recruits the Human Complement Regulatory Protein Factor H. THE JOURNAL OF IMMUNOLOGY 2012; 189:3593-9. [DOI: 10.4049/jimmunol.1201145] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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The rickettsial OmpB β-peptide of Rickettsia conorii is sufficient to facilitate factor H-mediated serum resistance. Infect Immun 2012; 80:2735-43. [PMID: 22615250 DOI: 10.1128/iai.00349-12] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Pathogenic species of the spotted fever group Rickettsia are subjected to repeated exposures to the host complement system through cyclic infections of mammalian and tick hosts. The serum complement machinery is a formidable obstacle for bacteria to overcome if they endeavor to endure this endozoonotic cycle. We have previously demonstrated that that the etiologic agent of Mediterranean spotted fever, Rickettsia conorii, is susceptible to complement-mediated killing only in the presence of specific monoclonal antibodies. We have also shown that in the absence of particular neutralizing antibody, R. conorii is resistant to the effects of serum complement. We therefore hypothesized that the interactions between fluid-phase complement regulators and conserved rickettsial outer membrane-associated proteins are critical to mediate serum resistance. We demonstrate here that R. conorii specifically interacts with the soluble host complement inhibitor, factor H. Depletion of factor H from normal human serum renders R. conorii more susceptible to C3 and membrane attack complex deposition and to complement-mediated killing. We identified the autotransporter protein rickettsial OmpB (rOmpB) as a factor H ligand and further demonstrate that the rOmpB β-peptide is sufficient to mediate resistance to the bactericidal properties of human serum. Taken together, these data reveal an additional function for the highly conserved rickettsial surface cell antigen, rOmpB, and suggest that the ability to evade complement-mediated clearance from the hematogenous circulation is a novel virulence attribute for this class of pathogens.
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Ho DK, Riva R, Kirjavainen V, Jarva H, Ginström E, Blom AM, Skurnik M, Meri S. Functional Recruitment of the Human Complement Inhibitor C4BP toYersinia pseudotuberculosisOuter Membrane Protein Ail. THE JOURNAL OF IMMUNOLOGY 2012; 188:4450-9. [DOI: 10.4049/jimmunol.1103149] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Zou M, Keelara S, Thakur S. Molecular Characterization ofSalmonella entericaSerotype Enteritidis Isolates from Humans by Antimicrobial Resistance, Virulence Genes, and Pulsed-Field Gel Electrophoresis. Foodborne Pathog Dis 2012; 9:232-8. [DOI: 10.1089/fpd.2011.1012] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Ming Zou
- College of Animal Science and Veterinary Medicine, Qingdao Agricultural University, Qingdao, China
| | - Shivaramu Keelara
- Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina
| | - Siddhartha Thakur
- Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina
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Functional recruitment of human complement inhibitor C4B-binding protein to outer membrane protein Rck of Salmonella. PLoS One 2011; 6:e27546. [PMID: 22102907 PMCID: PMC3213152 DOI: 10.1371/journal.pone.0027546] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2011] [Accepted: 10/19/2011] [Indexed: 12/05/2022] Open
Abstract
Resistance to complement mediated killing, or serum resistance, is a common trait of pathogenic bacteria. Rck is a 17 kDa outer membrane protein encoded on the virulence plasmid of Salmonella enterica serovars Typhimurium and Enteritidis. When expressed in either E. coli or S. enterica Typhimurium, Rck confers LPS-independent serum resistance as well as the ability to bind to and invade mammalian cells. Having recently shown that Rck binds the inhibitor of the alternative pathway of complement, factor H (fH), we hypothesized that Rck can also bind the inhibitor of the classical and lectin pathways, C4b-binding protein (C4BP). Using flow cytometry and direct binding assays, we demonstrate that E. coli expressing Rck binds C4BP from heat-inactivated serum and by using the purified protein. No binding was detected in the absence of Rck expression. C4BP bound to Rck is functional, as we observed factor I-mediated cleavage of C4b in cofactor assays. In competition assays, binding of radiolabeled C4BP to Rck was reduced by increasing concentrations of unlabeled protein. No effect was observed by increasing heparin or salt concentrations, suggesting mainly non-ionic interactions. Reduced binding of C4BP mutants lacking complement control protein domains (CCPs) 7 or 8 was observed compared to wt C4BP, suggesting that these CCPs are involved in Rck binding. While these findings are restricted to Rck expression in E. coli, these data suggest that C4BP binding may be an additional mechanism of Rck-mediated complement resistance.
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Effect of deletion of genes involved in lipopolysaccharide core and O-antigen synthesis on virulence and immunogenicity of Salmonella enterica serovar typhimurium. Infect Immun 2011; 79:4227-39. [PMID: 21768282 DOI: 10.1128/iai.05398-11] [Citation(s) in RCA: 145] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Lipopolysaccharide (LPS) is a major virulence factor of Salmonella enterica serovar Typhimurium and is composed of lipid A, core oligosaccharide (C-OS), and O-antigen polysaccharide (O-PS). While the functions of the gene products involved in synthesis of core and O-antigen have been elucidated, the effect of removing O-antigen and core sugars on the virulence and immunogenicity of Salmonella enterica serovar Typhimurium has not been systematically studied. We introduced nonpolar, defined deletion mutations in waaG (rfaG), waaI (rfaI), rfaH, waaJ (rfaJ), wbaP (rfbP), waaL (rfaL), or wzy (rfc) into wild-type S. Typhimurium. The LPS structure was confirmed, and a number of in vitro and in vivo properties of each mutant were analyzed. All mutants were significantly attenuated compared to the wild-type parent when administered orally to BALB/c mice and were less invasive in host tissues. Strains with ΔwaaG and ΔwaaI mutations, in particular, were deficient in colonization of Peyer's patches and liver. This deficiency could be partially overcome in the ΔwaaI mutant when it was administered intranasally. In the context of an attenuated vaccine strain delivering the pneumococcal antigen PspA, all of the mutations tested resulted in reduced immune responses against PspA and Salmonella antigens. Our results indicate that nonreversible truncation of the outer core is not a viable option for developing a live oral Salmonella vaccine, while a wzy mutant that retains one O-antigen unit is adequate for stimulating the optimal protective immunity to homologous or heterologous antigens by oral, intranasal, or intraperitoneal routes of administration.
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Ahmer BMM, Gunn JS. Interaction of Salmonella spp. with the Intestinal Microbiota. Front Microbiol 2011; 2:101. [PMID: 21772831 PMCID: PMC3131049 DOI: 10.3389/fmicb.2011.00101] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Accepted: 04/25/2011] [Indexed: 12/20/2022] Open
Abstract
Salmonella spp. are major cause of human morbidity and mortality worldwide. Upon entry into the human host, Salmonella spp. must overcome the resistance to colonization mediated by the gut microbiota and the innate immune system. They successfully accomplish this by inducing inflammation and mechanisms of innate immune defense. Many models have been developed to study Salmonella spp. interaction with the microbiota that have helped to identify factors necessary to overcome colonization resistance and to mediate disease. Here we review the current state of studies into this important pathogen/microbiota/host interaction in the mammalian gastrointestinal tract.
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Affiliation(s)
- Brian M M Ahmer
- The Department of Microbiology, The Ohio State University Columbus, OH, USA
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Soares JA, Ahmer BMM. Detection of acyl-homoserine lactones by Escherichia and Salmonella. Curr Opin Microbiol 2011; 14:188-93. [PMID: 21353625 DOI: 10.1016/j.mib.2011.01.006] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2010] [Accepted: 01/28/2011] [Indexed: 02/07/2023]
Abstract
Escherichia and Salmonella do not synthesize quorum-sensing signaling molecules of the N-acyl-l-homoserine lactone (AHL) type but they can detect AHLs produced by other species of bacteria. AHLs are present in the bovine rumen but not in the remainder of the gastrointestinal tract. Enterohemorrhagic E. coli (EHEC) responds to AHLs extracted from the bovine rumen. Salmonella fails to detect AHLs in the gastrointestinal tracts of pathogen-free mice or pigs, suggesting that AHLs are not present. However, Salmonella does detect the AHL production of Yersinia enterocolitica in mouse Peyer's patches. In response to AHLs, EHEC represses flagellar genes and the LEE pathogenicity island while it activates the acid fitness island, whereas Salmonella activates the rck operon and a gene, srgE, encoding a putative Type III secreted effector.
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Affiliation(s)
- Jitesh A Soares
- Department of Microbiology, Ohio State University, 484 West 12th Avenue, 376 Biological Sciences Building, Columbus, OH 43210, USA
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