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Chatterjee R, Setty SRG, Chakravortty D. SNAREs: a double-edged sword for intravacuolar bacterial pathogens within host cells. Trends Microbiol 2024; 32:477-493. [PMID: 38040624 DOI: 10.1016/j.tim.2023.11.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2023] [Revised: 11/07/2023] [Accepted: 11/08/2023] [Indexed: 12/03/2023]
Abstract
In the tug-of-war between host and pathogen, both evolve to combat each other's defence arsenals. Intracellular phagosomal bacteria have developed strategies to modify the vacuolar niche to suit their requirements best. Conversely, the host tries to target the pathogen-containing vacuoles towards the degradative pathways. The host cells use a robust system through intracellular trafficking to maintain homeostasis inside the cellular milieu. In parallel, intracellular bacterial pathogens have coevolved with the host to harbour strategies to manipulate cellular pathways, organelles, and cargoes, facilitating the conversion of the phagosome into a modified pathogen-containing vacuole (PCV). Key molecular regulators of intracellular traffic, such as changes in the organelle (phospholipid) composition, recruitment of small GTPases and associated effectors, soluble N-ethylmaleimide-sensitive factor-activating protein receptors (SNAREs), etc., are hijacked to evade lysosomal degradation. Legionella, Salmonella, Coxiella, Chlamydia, Mycobacterium, and Brucella are examples of pathogens which diverge from the endocytic pathway by using effector-mediated mechanisms to overcome the challenges and establish their intracellular niches. These pathogens extensively utilise and modulate the end processes of secretory pathways, particularly SNAREs, in repurposing the PCV into specialised compartments resembling the host organelles within the secretory network; at the same time, they avoid being degraded by the host's cellular mechanisms. Here, we discuss the recent research advances on the host-pathogen interaction/crosstalk that involves host SNAREs, conserved cellular processes, and the ongoing host-pathogen defence mechanisms in the molecular arms race against each other. The current knowledge of SNAREs, and intravacuolar bacterial pathogen interactions, enables us to understand host cellular innate immune pathways, maintenance of homeostasis, and potential therapeutic strategies to combat ever-growing antimicrobial resistance.
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Affiliation(s)
- Ritika Chatterjee
- Department of Microbiology and Cell Biology, Division of Biological Sciences, Indian Institute of Science, Bangalore, Karnataka, India
| | - Subba Rao Gangi Setty
- Department of Microbiology and Cell Biology, Division of Biological Sciences, Indian Institute of Science, Bangalore, Karnataka, India.
| | - Dipshikha Chakravortty
- Department of Microbiology and Cell Biology, Division of Biological Sciences, Indian Institute of Science, Bangalore, Karnataka, India; Adjunct Faculty, Indian Institute of Science Research and Education, Thiruvananthapuram, Kerala, India.
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Sang S, Song W, Lu L, Ou Q, Guan Y, Tao H, Wang Y, Liu C. The Trimeric Autotransporter Adhesin SadA from Salmonella spp. as a Novel Bacterial Surface Display System. Vaccines (Basel) 2024; 12:399. [PMID: 38675781 PMCID: PMC11054257 DOI: 10.3390/vaccines12040399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2024] [Revised: 03/25/2024] [Accepted: 03/26/2024] [Indexed: 04/28/2024] Open
Abstract
Bacterial surface display platforms have been developed for applications such as vaccine delivery and peptide library screening. The type V secretion system is an attractive anchoring motif for the surface expression of foreign proteins in gram-negative bacteria. SadA belongs to subtype C of the type V secretion system derived from Salmonella spp. and promotes biofilm formation and host cell adherence. The inner membrane lipoprotein SadB is important for SadA translocation. In this study, SadA was used as an anchoring motif to expose heterologous proteins in Salmonella typhimurium using SadB. The ability of SadA to display heterologous proteins on the S. typhimurium surface in the presence of SadB was approximately three-fold higher than that in its absence of SadB. Compared to full-length SadA, truncated SadAs (SadA877 and SadA269) showed similar display capacities when exposing the B-cell epitopes of urease B from Helicobacter pylori (UreB158-172aa and UreB349-363aa). We grafted different protein domains, including mScarlet (red fluorescent protein), the urease B fragment (UreBm) from H. pylori SS1, and/or protective antigen domain 4 from Bacillus anthracis A16R (PAD4), onto SadA877 or SadA1292. Whole-cell dot blotting, immunofluorescence, and flow cytometric analyses confirmed the localization of Flag×3-mScarlet (~30 kDa) and Flag×3-UreBm-mScarlet (~58 kDa) to the S. typhimurium surface using truncated SadA877 or SadA1292 as an anchoring motif. However, Flag×3-UreBm-PAD4-mScarlet (~75 kDa) was displayed on S. typhimurium using SadA1292. The oral administrated pSadBA1292-FUM/StmΔygeAΔmurI and pSadBA877-FUM/StmΔygeAΔmurI could elicit a significant mucosal and humoral immunity response. SadA could thus be used as an anchoring motif for the surface expression of large heterologous proteins as a potential strategy for attenuated bacterial vaccine development.
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Affiliation(s)
- Shuli Sang
- State Key Laboratory of Pathogen and Biosecurity, Institute of Biotechnology, Academy of Military Medical Sciences, 20 Dongda Street, Fengtai District, Beijing 100071, China; (S.S.); (W.S.); (L.L.); (Q.O.); (Y.G.); (H.T.)
| | - Wenge Song
- State Key Laboratory of Pathogen and Biosecurity, Institute of Biotechnology, Academy of Military Medical Sciences, 20 Dongda Street, Fengtai District, Beijing 100071, China; (S.S.); (W.S.); (L.L.); (Q.O.); (Y.G.); (H.T.)
| | - Lu Lu
- State Key Laboratory of Pathogen and Biosecurity, Institute of Biotechnology, Academy of Military Medical Sciences, 20 Dongda Street, Fengtai District, Beijing 100071, China; (S.S.); (W.S.); (L.L.); (Q.O.); (Y.G.); (H.T.)
| | - Qikun Ou
- State Key Laboratory of Pathogen and Biosecurity, Institute of Biotechnology, Academy of Military Medical Sciences, 20 Dongda Street, Fengtai District, Beijing 100071, China; (S.S.); (W.S.); (L.L.); (Q.O.); (Y.G.); (H.T.)
- School of Basic Medical Sciences, Guangxi Medical University, 22 Shuangyong Road, Nanning 530021, China
| | - Yiyan Guan
- State Key Laboratory of Pathogen and Biosecurity, Institute of Biotechnology, Academy of Military Medical Sciences, 20 Dongda Street, Fengtai District, Beijing 100071, China; (S.S.); (W.S.); (L.L.); (Q.O.); (Y.G.); (H.T.)
| | - Haoxia Tao
- State Key Laboratory of Pathogen and Biosecurity, Institute of Biotechnology, Academy of Military Medical Sciences, 20 Dongda Street, Fengtai District, Beijing 100071, China; (S.S.); (W.S.); (L.L.); (Q.O.); (Y.G.); (H.T.)
| | - Yanchun Wang
- State Key Laboratory of Pathogen and Biosecurity, Institute of Biotechnology, Academy of Military Medical Sciences, 20 Dongda Street, Fengtai District, Beijing 100071, China; (S.S.); (W.S.); (L.L.); (Q.O.); (Y.G.); (H.T.)
| | - Chunjie Liu
- State Key Laboratory of Pathogen and Biosecurity, Institute of Biotechnology, Academy of Military Medical Sciences, 20 Dongda Street, Fengtai District, Beijing 100071, China; (S.S.); (W.S.); (L.L.); (Q.O.); (Y.G.); (H.T.)
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Wang XY, Miao T, Wang Y, Guo Z, Yang JL, Liang X. Complete genome sequence of Psychrobacter cibarius AOSW16051, a trimeric autotransporter adhesin synthesizing bacterium isolated from the Baltic Sea. Mar Genomics 2024; 74:101082. [PMID: 38485290 DOI: 10.1016/j.margen.2023.101082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 11/10/2023] [Accepted: 12/08/2023] [Indexed: 03/19/2024]
Abstract
Bacteria of the genus Psychrobacter are widely distributed in the global low-temperature marine environment and have been studied for their effects on the settlement and metamorphosis of marine invertebrates. Psychrobacter cibarius AOSW16051 was isolated from the surface water samples of the Baltic Sea on the edge of the Arctic Ocean. Here, we present the complete genome of strain AOSW16051, which consists of a circular chromosome composed of 3,425,040 nucleotides with 42.98% G + C content and a circular plasmid composed of 5846 nucleotides with 38.66% G + C content. The genes predicted in this strain showed its strong outer membrane system, type VI secretion system and adhesion system. Trimeric autotransporter adhesins (TAAs) has been identified in the genome of P. cibarius AOSW16051, which has a variety of biological functions in interacting with host cells. However, there are no reports on TAAs in marine bacteria and aquatic pathogenic bacteria. By analyzing the genomic data, we can gain valuable insights to enhance our understanding of the physiological characteristics of P. cibarius, as well as the biological functions of TAAs and their role in triggering metamorphosis of invertebrate larvae.
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Affiliation(s)
- Xiao-Yu Wang
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai, China; China-Portugal Belt and Road Joint Laboratory on Space & Sea Technology Advanced Research, Shanghai, China; Shanghai Collaborative Innovation Center for Cultivating Elite Breeds and Green-culture of Aquaculture animals, Shanghai, China
| | - Tianyin Miao
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai, China; China-Portugal Belt and Road Joint Laboratory on Space & Sea Technology Advanced Research, Shanghai, China
| | - Yuyi Wang
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai, China; China-Portugal Belt and Road Joint Laboratory on Space & Sea Technology Advanced Research, Shanghai, China; Shanghai Collaborative Innovation Center for Cultivating Elite Breeds and Green-culture of Aquaculture animals, Shanghai, China
| | - Zhangwei Guo
- College of Ocean Science and Engineering, Shanghai Maritime University, Shanghai 201306, China.
| | - Jin-Long Yang
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai, China; China-Portugal Belt and Road Joint Laboratory on Space & Sea Technology Advanced Research, Shanghai, China; Shanghai Collaborative Innovation Center for Cultivating Elite Breeds and Green-culture of Aquaculture animals, Shanghai, China
| | - Xiao Liang
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai, China; China-Portugal Belt and Road Joint Laboratory on Space & Sea Technology Advanced Research, Shanghai, China; Shanghai Collaborative Innovation Center for Cultivating Elite Breeds and Green-culture of Aquaculture animals, Shanghai, China.
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Meuskens I, Kristiansen PE, Bardiaux B, Koynarev VR, Hatlem D, Prydz K, Lund R, Izadi-Pruneyre N, Linke D. A poly-proline II helix in YadA from Yersinia enterocolitica serotype O:9 facilitates heparin binding through electrostatic interactions. FEBS J 2024; 291:761-777. [PMID: 37953437 DOI: 10.1111/febs.17001] [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: 07/14/2023] [Revised: 10/25/2023] [Accepted: 11/09/2023] [Indexed: 11/14/2023]
Abstract
Poly-proline II helices are secondary structure motifs frequently found in ligand-binding sites. They exhibit increased flexibility and solvent exposure compared to the strongly hydrogen-bonded α-helices or β-strands and can therefore easily be misinterpreted as completely unstructured regions with an extremely high rotational freedom. Here, we show that the adhesin YadA of Yersinia enterocolitica serotype O:9 contains a poly-proline II helix interaction motif in the N-terminal region. The motif is involved in the interaction of YadAO:9 with heparin, a host glycosaminoglycan. We show that the basic residues within the N-terminal motif of YadA are required for electrostatic interactions with the sulfate groups of heparin. Biophysical methods including CD spectroscopy, solution-state NMR and SAXS all independently support the presence of a poly-proline helix allowing YadAO:9 binding to the rigid heparin. Lastly, we show that host cells deficient in sulfation of heparin and heparan sulfate are not targeted by YadAO:9 -mediated adhesion. We speculate that the YadAO:9 -heparin interaction plays an important and highly strain-specific role in the pathogenicity of Yersinia enterocolitica serotype O:9.
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Affiliation(s)
- Ina Meuskens
- Department of Biosciences, University of Oslo, Norway
| | | | - Benjamin Bardiaux
- Structural Bioinformatics Unit, CNRS UMR3528, Institut Pasteur, Université de Paris-Cité, France
| | | | - Daniel Hatlem
- Department of Biosciences, University of Oslo, Norway
| | | | - Reidar Lund
- Department of Chemistry, University of Oslo, Norway
| | - Nadia Izadi-Pruneyre
- Bacterial Transmembrane Systems Unit, CNRS UMR3528, Institut Pasteur, Université de Paris-Cité, France
| | - Dirk Linke
- Department of Biosciences, University of Oslo, Norway
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Mintz KP, Danforth DR, Ruiz T. The Trimeric Autotransporter Adhesin EmaA and Infective Endocarditis. Pathogens 2024; 13:99. [PMID: 38392837 PMCID: PMC10892112 DOI: 10.3390/pathogens13020099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 01/18/2024] [Accepted: 01/22/2024] [Indexed: 02/25/2024] Open
Abstract
Infective endocarditis (IE), a disease of the endocardial surface of the heart, is usually of bacterial origin and disproportionally affects individuals with underlying structural heart disease. Although IE is typically associated with Gram-positive bacteria, a minority of cases are caused by a group of Gram-negative species referred to as the HACEK group. These species, classically associated with the oral cavity, consist of bacteria from the genera Haemophilus (excluding Haemophilus influenzae), Aggregatibacter, Cardiobacterium, Eikenella, and Kingella. Aggregatibacter actinomycetemcomitans, a bacterium of the Pasteurellaceae family, is classically associated with Aggressive Periodontitis and is also concomitant with the chronic form of the disease. Bacterial colonization of the oral cavity serves as a reservoir for infection at distal body sites via hematological spreading. A. actinomycetemcomitans adheres to and causes disease at multiple physiologic niches using a diverse array of bacterial cell surface structures, which include both fimbrial and nonfimbrial adhesins. The nonfimbrial adhesin EmaA (extracellular matrix binding protein adhesin A), which displays sequence heterogeneity dependent on the serotype of the bacterium, has been identified as a virulence determinant in the initiation of IE. In this chapter, we will discuss the known biochemical, molecular, and structural aspects of this protein, including its interactions with extracellular matrix components and how this multifunctional adhesin may contribute to the pathogenicity of A. actinomycetemcomitans.
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Affiliation(s)
- Keith P. Mintz
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, VT 05405, USA;
| | - David R. Danforth
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, VT 05405, USA;
| | - Teresa Ruiz
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, VT 05405, USA;
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Zheng K, Liang Y, Paez-Espino D, Zou X, Gao C, Shao H, Sung YY, Mok WJ, Wong LL, Zhang YZ, Tian J, Chen F, Jiao N, Suttle CA, He J, McMinn A, Wang M. Identification of hidden N4-like viruses and their interactions with hosts. mSystems 2023; 8:e0019723. [PMID: 37702511 PMCID: PMC10654107 DOI: 10.1128/msystems.00197-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 07/19/2023] [Indexed: 09/14/2023] Open
Abstract
IMPORTANCE The findings of this study are significant, as N4-like viruses represent a unique viral lineage with a distinct replication mechanism and a conserved core genome. This work has resulted in a comprehensive global map of the entire N4-like viral lineage, including information on their distribution in different biomes, evolutionary divergence, genomic diversity, and the potential for viral-mediated host metabolic reprogramming. As such, this work significantly contributes to our understanding of the ecological function and viral-host interactions of bacteriophages.
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Affiliation(s)
- Kaiyang Zheng
- Key Laboratory of Polar Oceanography and Global Ocean Change, Frontiers Science Center for Deep Ocean Multispheres and Earth System, College of Marine Life Sciences, Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, China
- UMT-OUC Joint Centre for Marine Studies, Qingdao, China
| | - Yantao Liang
- Key Laboratory of Polar Oceanography and Global Ocean Change, Frontiers Science Center for Deep Ocean Multispheres and Earth System, College of Marine Life Sciences, Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, China
- UMT-OUC Joint Centre for Marine Studies, Qingdao, China
| | - David Paez-Espino
- DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, California, USA
- Mammoth Biosciences Inc., South San Francisco, California, USA
| | - Xiao Zou
- Qingdao Central Hospital, Qingdao, China
| | - Chen Gao
- Key Laboratory of Polar Oceanography and Global Ocean Change, Frontiers Science Center for Deep Ocean Multispheres and Earth System, College of Marine Life Sciences, Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, China
- UMT-OUC Joint Centre for Marine Studies, Qingdao, China
| | - Hongbing Shao
- Key Laboratory of Polar Oceanography and Global Ocean Change, Frontiers Science Center for Deep Ocean Multispheres and Earth System, College of Marine Life Sciences, Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, China
- UMT-OUC Joint Centre for Marine Studies, Qingdao, China
| | - Yeong Yik Sung
- UMT-OUC Joint Centre for Marine Studies, Qingdao, China
- Institute of Marine Biotechnology, Universiti Malaysia Terengganu (UMT), Kuala Terengganu, Malaysia
| | - Wen Jye Mok
- UMT-OUC Joint Centre for Marine Studies, Qingdao, China
- Institute of Marine Biotechnology, Universiti Malaysia Terengganu (UMT), Kuala Terengganu, Malaysia
| | - Li Lian Wong
- UMT-OUC Joint Centre for Marine Studies, Qingdao, China
- Institute of Marine Biotechnology, Universiti Malaysia Terengganu (UMT), Kuala Terengganu, Malaysia
| | - Yu-Zhong Zhang
- Key Laboratory of Polar Oceanography and Global Ocean Change, Frontiers Science Center for Deep Ocean Multispheres and Earth System, College of Marine Life Sciences, Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, China
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, China
| | - Jiwei Tian
- Key Laboratory of Physical Oceanography, Ministry of Education, Ocean University of China, Qingdao, China
| | - Feng Chen
- Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science, Baltimore, Maryland, USA
| | - Nianzhi Jiao
- State Key Laboratory of Marine Environmental Sciences, Institute of Marine Microbes and Ecospheres, Xiamen University, Xiamen, China
| | - Curtis A. Suttle
- Department of Earth, Ocean and Atmospheric Sciences, Institute for the Oceans and Fisheries, The University of British Columbia, Vancouver, British Columbia, Canada
- Department of Microbiology and Immunology, Institute for the Oceans and Fisheries, The University of British Columbia, Vancouver, British Columbia, Canada
- Department of Botany, Institute for the Oceans and Fisheries, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Jianfeng He
- SOA Key Laboratory for Polar Science, Polar Research Institute of China, Shanghai, China
| | - Andrew McMinn
- Key Laboratory of Polar Oceanography and Global Ocean Change, Frontiers Science Center for Deep Ocean Multispheres and Earth System, College of Marine Life Sciences, Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, China
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, Australia
| | - Min Wang
- Key Laboratory of Polar Oceanography and Global Ocean Change, Frontiers Science Center for Deep Ocean Multispheres and Earth System, College of Marine Life Sciences, Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, China
- UMT-OUC Joint Centre for Marine Studies, Qingdao, China
- The Affiliated Hospital of Qingdao University, Qingdao, China
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Jin X, Gou Y, Xin Y, Li J, Sun J, Li T, Feng J. Advancements in understanding the molecular and immune mechanisms of Bartonella pathogenicity. Front Microbiol 2023; 14:1196700. [PMID: 37362930 PMCID: PMC10288214 DOI: 10.3389/fmicb.2023.1196700] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 05/23/2023] [Indexed: 06/28/2023] Open
Abstract
Bartonellae are considered to be emerging opportunistic pathogens. The bacteria are transmitted by blood-sucking arthropods, and their hosts are a wide range of mammals including humans. After a protective barrier breach in mammals, Bartonella colonizes endothelial cells (ECs), enters the bloodstream, and infects erythrocytes. Current research primarily focuses on investigating the interaction between Bartonella and ECs and erythrocytes, with recent attention also paid to immune-related aspects. Various molecules related to Bartonella's pathogenicity have been identified. The present review aims to provide a comprehensive overview of the newly described molecular and immune responses associated with Bartonella's pathogenicity.
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Affiliation(s)
- Xiaoxia Jin
- Gansu Provincial Key Laboratory of Evidence Based Medicine and Clinical Translation and Lanzhou Center for Tuberculosis Research, School of Basic Medical Sciences, Lanzhou University, Lanzhou, China
| | - Yuze Gou
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, Lanzhou, China
| | - Yuxian Xin
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, Lanzhou, China
| | - Jingwei Li
- Gansu Provincial Key Laboratory of Evidence Based Medicine and Clinical Translation and Lanzhou Center for Tuberculosis Research, School of Basic Medical Sciences, Lanzhou University, Lanzhou, China
| | - Jingrong Sun
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, Lanzhou, China
| | - Tingting Li
- Gansu Provincial Key Laboratory of Evidence Based Medicine and Clinical Translation and Lanzhou Center for Tuberculosis Research, School of Basic Medical Sciences, Lanzhou University, Lanzhou, China
| | - Jie Feng
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, Lanzhou, China
- State Key Laboratory of Veterinary Etiological Biology, College of Veterinary Medicine, Lanzhou University, Lanzhou, China
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Aptasensor for the Detection of Moraxella catarrhalis Adhesin UspA2. Bioengineering (Basel) 2023; 10:bioengineering10020178. [PMID: 36829672 PMCID: PMC9951875 DOI: 10.3390/bioengineering10020178] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 01/20/2023] [Accepted: 01/27/2023] [Indexed: 02/04/2023] Open
Abstract
Innovative point-of-care (PoC) diagnostic platforms are desirable to surpass the deficiencies of conventional laboratory diagnostic methods for bacterial infections and to tackle the growing antimicrobial resistance crisis. In this study, a workflow was implemented, comprising the identification of new aptamers with high affinity for the ubiquitous surface protein A2 (UspA2) of the bacterial pathogen Moraxella catarrhalis and the development of an electrochemical biosensor functionalized with the best-performing aptamer as a bioreceptor to detect UspA2. After cell-systematic evolution of ligands by exponential enrichment (cell-SELEX) was performed, next-generation sequencing was used to sequence the final aptamer pool. The most frequent aptamer sequences were further evaluated using bioinformatic tools. The two most promising aptamer candidates, Apt1 and Apt1_RC (Apt1 reverse complement), had Kd values of 214.4 and 3.4 nM, respectively. Finally, a simple and label-free electrochemical biosensor was functionalized with Apt1_RC. The aptasensor surface modifications were confirmed by impedance spectroscopy and cyclic voltammetry. The ability to detect UspA2 was evaluated by square wave voltammetry, exhibiting a linear detection range of 4.0 × 104-7.0 × 107 CFU mL-1, a square correlation coefficient superior to 0.99 and a limit of detection of 4.0 × 104 CFU mL-1 at pH 5.0. The workflow described has the potential to be part of a sensitive PoC diagnostic platform to detect and quantify M. catarrhalis from biological samples.
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Thibau A, Vaca DJ, Bagowski M, Hipp K, Bender D, Ballhorn W, Linke D, Kempf VAJ. Adhesion of Bartonella henselae to Fibronectin Is Mediated via Repetitive Motifs Present in the Stalk of Bartonella Adhesin A. Microbiol Spectr 2022; 10:e0211722. [PMID: 36165788 PMCID: PMC9602544 DOI: 10.1128/spectrum.02117-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 09/06/2022] [Indexed: 12/31/2022] Open
Abstract
Adhesion to host cells is the first and most crucial step in infections with pathogenic Gram-negative bacteria and is often mediated by trimeric autotransporter adhesins (TAAs). Bartonella henselae targets the extracellular matrix glycoprotein fibronectin (Fn) via the Bartonella adhesin A (BadA) attaching the bacteria to the host cell. The TAA BadA is characterized by a highly repetitive passenger domain consisting of 30 neck/stalk domains with various degrees of similarity. To elucidate the motif sequences mediating Fn binding, we generated 10 modified BadA constructs and verified their expression via Western blotting, confocal laser scanning, and electron microscopy. We analyzed their ability to bind human plasma Fn using quantitative whole-cell enzyme-linked immunosorbent assays (ELISAs) and fluorescence microscopy. Polyclonal antibodies targeting a 15-mer amino acid motif sequence proved to reduce Fn binding. We suggest that BadA adheres to Fn in a cumulative effort with quick saturation primarily via unpaired β-strands appearing in motifs repeatedly present throughout the neck/stalk region. In addition, we demonstrated that the length of truncated BadA constructs correlates with the immunoreactivity of human patient sera. The identification of BadA-Fn binding regions will support the development of new "antiadhesive" compounds inhibiting the initial adherence of B. henselae and other TAA-expressing pathogens to host cells. IMPORTANCE Trimeric autotransporter adhesins (TAAs) are important virulence factors and are widely present in various pathogenic Gram-negative bacteria. TAA-expressing bacteria cause a wide spectrum of human diseases, such as cat scratch disease (Bartonella henselae), enterocolitis (Yersinia enterocolitica), meningitis (Neisseria meningitis), and bloodstream infections (multidrug-resistant Acinetobacter baumannii). TAA-targeted antiadhesive strategies (against, e.g., Bartonella adhesin A [BadA], Yersinia adhesin A [YadA], Neisseria adhesin A [NadA], and Acinetobacter trimeric autotransporter [Ata]) might represent a universal strategy to counteract such bacterial infections. BadA is one of the best characterized TAAs, and because of its high number of (sub)domains, it serves as an attractive adhesin to study the domain-function relationship of TAAs in the infection process. The identification of common binding motifs between TAAs (here, BadA) and their major binding partner (here, fibronectin) provides a basis toward the design of novel "antiadhesive" compounds preventing the initial adherence of Gram-negative bacteria in infections.
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Affiliation(s)
- Arno Thibau
- Institute for Medical Microbiology and Infection Control, University Hospital, Goethe University, Frankfurt, Germany
| | - Diana J. Vaca
- Institute for Medical Microbiology and Infection Control, University Hospital, Goethe University, Frankfurt, Germany
| | - Marlene Bagowski
- Institute for Medical Microbiology and Infection Control, University Hospital, Goethe University, Frankfurt, Germany
| | - Katharina Hipp
- Electron Microscopy Facility, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Daniela Bender
- Federal Institute for Vaccines and Biomedicines, Department of Virology, Paul-Ehrlich-Institut, Langen, Germany
| | - Wibke Ballhorn
- Institute for Medical Microbiology and Infection Control, University Hospital, Goethe University, Frankfurt, Germany
| | - Dirk Linke
- Section for Genetics and Evolutionary Biology, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Volkhard A. J. Kempf
- Institute for Medical Microbiology and Infection Control, University Hospital, Goethe University, Frankfurt, Germany
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10
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Kiessling AR, Harris SA, Weimer KM, Wells G, Goldman A. The C-terminal head domain of Burkholderia pseudomallei BpaC has a striking hydrophilic core with an extensive solvent network. Mol Microbiol 2022; 118:77-91. [PMID: 35703459 PMCID: PMC9543794 DOI: 10.1111/mmi.14953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 06/07/2022] [Accepted: 06/09/2022] [Indexed: 11/27/2022]
Abstract
Gram‐negative pathogens like Burkholderia pseudomallei use trimeric autotransporter adhesins such as BpaC as key molecules in their pathogenicity. Our 1.4 Å crystal structure of the membrane‐proximal part of the BpaC head domain shows that the domain is exclusively made of left‐handed parallel β‐roll repeats. This, the largest such structure solved, has two unique features. First, the core, rather than being composed of the canonical hydrophobic Ile and Val, is made up primarily of the hydrophilic Thr and Asn, with two different solvent channels. Second, comparing BpaC to all other left‐handed parallel β‐roll structures showed that the position of the head domain in the protein correlates with the number and type of charged residues. In BpaC, only negatively charged residues face the solvent—in stark contrast to the primarily positive surface charge of the left‐handed parallel β‐roll “type” protein, YadA. We propose extending the definitions of these head domains to include the BpaC‐like head domain as a separate subtype, based on its unusual sequence, position, and charge. We speculate that the function of left‐handed parallel β‐roll structures may differ depending on their position in the structure.
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Affiliation(s)
- Andreas R Kiessling
- Astbury Centre for Structural Molecular Biology, School of Biomedical Sciences, University of Leeds, Leeds, UK
| | - Sarah A Harris
- Astbury Centre for Structural Molecular Biology, School of Physics and Astronomy, University of Leeds, Leeds, UK
| | - Kathleen M Weimer
- Astbury Centre for Structural Molecular Biology, School of Biomedical Sciences, University of Leeds, Leeds, UK.,IGBMC, School of Life and Health Sciences, University of Strasbourg, Strasbourg, France
| | - Geoffrey Wells
- UCL School of Pharmacy, University College London, London, UK
| | - Adrian Goldman
- Astbury Centre for Structural Molecular Biology, School of Biomedical Sciences, University of Leeds, Leeds, UK.,MIBS, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
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11
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Tang-Siegel GG, Danforth DR, Tristano J, Ruiz T, Mintz KP. The serotype a-EmaA adhesin of Aggregatibacter actinomycetemcomitans does not require O-PS synthesis for collagen binding activity. MICROBIOLOGY (READING, ENGLAND) 2022; 168. [PMID: 35551696 DOI: 10.1099/mic.0.001191] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Aggregatibacter actinomycetemcomitans, a causative agent of periodontitis and non-oral diseases, synthesizes a trimeric extracellular matrix protein adhesin A (EmaA) that mediates collagen binding and biofilm formation. EmaA is found as two molecular forms, which correlate with the serotype of the bacterium. The canonical protein (b-EmaA), associated with serotypes b and c, has a monomeric molecular mass of 202 kDa. The collagen binding activity of b-EmaA is dependent on the presence of O-polysaccharide (O-PS), whereas biofilm activity is independent of O-PS synthesis. The EmaA associated with serotype a strains (a-EmaA) has a monomeric molecular mass of 173 kDa and differs in the amino acid sequence of the functional domain of the protein. In this study, a-emaA was confirmed to encode a protein that forms antenna-like appendages on the surface of the bacterium, which were found to be important for both collagen binding and biofilm formation. In an O-PS-deficient talose biosynthetic (tld) mutant strain, the electrophoretic mobility of the a-EmaA monomers was altered and the amount of membrane-associated EmaA was decreased when compared to the parent strain. The mass of biofilm formed remained unchanged. Interestingly, the collagen binding activity of the mutant strain was similar to the activity associated with the parent strain, which differs from that observed with the canonical b-EmaA isoform. These data suggest that the properties of the a-EmaA isoform are like those of b-EmaA, with the exception that collagen binding activity is independent of the presence or absence of the O-PS.
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Affiliation(s)
- Gaoyan G Tang-Siegel
- Department of Molecular Physiology & Biophysics, University of Vermont, Burlington, VT, USA
| | - David R Danforth
- Department of Microbiology & Molecular Genetics, University of Vermont, Burlington, VT, USA
| | - Jake Tristano
- Department of Microbiology & Molecular Genetics, University of Vermont, Burlington, VT, USA
| | - Teresa Ruiz
- Department of Molecular Physiology & Biophysics, University of Vermont, Burlington, VT, USA
| | - Keith P Mintz
- Department of Microbiology & Molecular Genetics, University of Vermont, Burlington, VT, USA
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12
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Thibau A, Hipp K, Vaca DJ, Chowdhury S, Malmström J, Saragliadis A, Ballhorn W, Linke D, Kempf VAJ. Long-Read Sequencing Reveals Genetic Adaptation of Bartonella Adhesin A Among Different Bartonella henselae Isolates. Front Microbiol 2022; 13:838267. [PMID: 35197960 PMCID: PMC8859334 DOI: 10.3389/fmicb.2022.838267] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 01/17/2022] [Indexed: 11/30/2022] Open
Abstract
Bartonella henselae is the causative agent of cat scratch disease and other clinical entities such as endocarditis and bacillary angiomatosis. The life cycle of this pathogen, with alternating host conditions, drives evolutionary and host-specific adaptations. Human, feline, and laboratory adapted B. henselae isolates often display genomic and phenotypic differences that are related to the expression of outer membrane proteins, for example the Bartonella adhesin A (BadA). This modularly-structured trimeric autotransporter adhesin is a major virulence factor of B. henselae and is crucial for the initial binding to the host via the extracellular matrix proteins fibronectin and collagen. By using next-generation long-read sequencing we demonstrate a conserved genome among eight B. henselae isolates and identify a variable genomic badA island with a diversified and highly repetitive badA gene flanked by badA pseudogenes. Two of the eight tested B. henselae strains lack BadA expression because of frameshift mutations. We suggest that active recombination mechanisms, possibly via phase variation (i.e., slipped-strand mispairing and site-specific recombination) within the repetitive badA island facilitate reshuffling of homologous domain arrays. The resulting variations among the different BadA proteins might contribute to host immune evasion and enhance long-term and efficient colonisation in the differing host environments. Considering the role of BadA as a key virulence factor, it remains important to check consistently and regularly for BadA surface expression during experimental infection procedures.
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Affiliation(s)
- Arno Thibau
- Institute for Medical Microbiology and Infection Control, University Hospital, Goethe University, Frankfurt am Main, Germany
| | - Katharina Hipp
- Electron Microscopy Facility, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Diana J Vaca
- Institute for Medical Microbiology and Infection Control, University Hospital, Goethe University, Frankfurt am Main, Germany
| | - Sounak Chowdhury
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Johan Malmström
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Athanasios Saragliadis
- Section for Genetics and Evolutionary Biology, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Wibke Ballhorn
- Institute for Medical Microbiology and Infection Control, University Hospital, Goethe University, Frankfurt am Main, Germany
| | - Dirk Linke
- Section for Genetics and Evolutionary Biology, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Volkhard A J Kempf
- Institute for Medical Microbiology and Infection Control, University Hospital, Goethe University, Frankfurt am Main, Germany
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13
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Ysebaert C, Castado C, Mortier MC, Rioux S, Feron C, Di Paolo E, Weynants V, Blais N, Devos N, Hermand P. UspA2 is a cross-protective Moraxella catarrhalis vaccine antigen. Vaccine 2021; 39:5641-5649. [PMID: 34446318 DOI: 10.1016/j.vaccine.2021.08.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 07/30/2021] [Accepted: 08/02/2021] [Indexed: 11/29/2022]
Abstract
Moraxella catarrhalis (Mcat) is a key pathogen associated with exacerbations of chronic obstructive pulmonary disease (COPD) in adults and playing a significant role in otitis media in children. A vaccine would help to reduce the morbidity and mortality associated with these diseases. UspA2 is an Mcat surface antigen considered earlier as vaccine candidate before the interest in this molecule vanished due to sequence variability. However, the observation that some conserved domains are the target of bactericidal antibodies prompted us to reconsider UspA2 as a potential vaccine antigen. We first determined its prevalence among the COPD patients from the AERIS study, as the prevalence of UspA2 in a COPD-restricted population had yet to be documented. The gene was found in all Mcat isolates either as UspA2 or UspA2H variant. The percentage of UspA2H variant was higher than in any report so far, reaching 51%. A potential link between the role of UspA2H in biofilm formation and this high prevalence is discussed. To study further UspA2 as a vaccine antigen, recombinant UspA2 molecules were designed and used in animal models and bactericidal assays. We showed that UspA2 is immunogenic and that UspA2 immunization clears Mcat pulmonary challenge in a mouse model. In a serum bactericidal assay, anti-UspA2 antibodies generated in mice, guinea pigs or rabbits were able to kill Mcat strains of various origins, including a subset of isolates from the AERIS study, cross-reacting with UspA2H and even UspA1, a closely related Mcat surface protein. In conclusion, UspA2 is a cross-reactive Mcat antigen presenting the characteristics of a vaccine candidate.
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14
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Structure of the Yersinia injectisome in intracellular host cell phagosomes revealed by cryo FIB electron tomography. J Struct Biol 2021; 213:107701. [PMID: 33549695 DOI: 10.1016/j.jsb.2021.107701] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 12/17/2020] [Accepted: 01/14/2021] [Indexed: 02/03/2023]
Abstract
Many pathogenic bacteria use the type III secretion system (T3SS), or injectisome, to secrete toxins into host cells. These protruding systems are primary targets for drug and vaccine development. Upon contact between injectisomes and host membranes, toxin secretion is triggered. How this works structurally and functionally is yet unknown. Using cryo-focused ion beam milling and cryo-electron tomography, we visualized injectisomes of Yersinia enterocolitica inside the phagosomes of infected human myeloid cells in a close-to-native state. We observed that a minimum needle length is required for injectisomes to contact the host membrane and bending of host membranes by some injectisomes that contact the host. Through subtomogram averaging, the structure of the entire injectisome was determined, which revealed structural differences in the cytosolic sorting platform compared to other bacteria. These findings contribute to understanding how injectisomes secrete toxins into host cells and provides the indispensable native context. The application of these cryo-electron microscopy techniques paves the way for the study of the 3D structure of infection-relevant protein complexes in host-pathogen interactions.
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15
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Berger C, Ravelli RBG, López-Iglesias C, Peters PJ. Endocytosed nanogold fiducials for improved in-situ cryo-electron tomography tilt-series alignment. J Struct Biol 2021; 213:107698. [PMID: 33545353 DOI: 10.1016/j.jsb.2021.107698] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 12/24/2020] [Accepted: 01/13/2021] [Indexed: 11/17/2022]
Abstract
Cryo-electron tomography (CET) on cryo-focused ion beam (FIB)-milled lamellae is becoming a powerful technique for determining the structure of macromolecular complexes in their native cellular environment. Prior to tomogram reconstruction, CET tilt-series recorded on FIB lamellae need to be aligned. Traditionally, CET tilt-series alignment is performed with 5-20 nm gold fiducials, but it has thus far proven difficult to apply this to FIB lamellae of eukaryotic cells. In here, we describe a simple method to allow uptake of bovine serum albumin (BSA)-gold fiducials into mammalian cells via endocytosis, which can subsequently be used as fiducials for tilt-series alignment of cryo-FIB lamellae. We compare the alignment of tilt-series with BSA-gold fiducials to fiducial-less patch-tracking, and find better alignment results with BSA-gold. This technique can contribute to understand cells at a structural and ultrastructural level with both cryo- and room-temperature electron tomography. Furthermore, fluorescently labeled BSA-gold has the potential to be used as fiducials for correlative light and electron microscopy studies.
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Affiliation(s)
- Casper Berger
- Division of Nanoscopy, Maastricht Multimodal Molecular Imaging Institute, Maastricht University, the Netherlands
| | - Raimond B G Ravelli
- Division of Nanoscopy, Maastricht Multimodal Molecular Imaging Institute, Maastricht University, the Netherlands
| | - Carmen López-Iglesias
- Division of Nanoscopy, Maastricht Multimodal Molecular Imaging Institute, Maastricht University, the Netherlands
| | - Peter J Peters
- Division of Nanoscopy, Maastricht Multimodal Molecular Imaging Institute, Maastricht University, the Netherlands.
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16
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Microscale communication between bacterial pathogens and the host epithelium. Genes Immun 2021; 22:247-254. [PMID: 34588625 PMCID: PMC8497271 DOI: 10.1038/s41435-021-00149-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 08/18/2021] [Accepted: 08/23/2021] [Indexed: 02/01/2023]
Abstract
Pathogenic bacteria have evolved a variety of highly selective adhesins allowing these microbes to engage specific surface determinants of their eukaryotic host cells. Receptor clustering induced by the multivalent microorganisms will not only anchor the bacteria to the tissue, but will inevitably trigger host cell signaling. It has become clear, that these bacteria-initiated signaling events can be seen as a form of localized communication with host epithelial cells. Such a microscale communication can have immediate consequences in the form of changes in host cell membrane morphology or cytoskeletal organization, but can also lead to transcriptional responses and medium- and long-term alterations in cellular physiology. In this review, we will discuss several examples of this form of microscale communication between bacterial pathogens and mammalian host cells and try to delineate their downstream ramifications in the infection process. Furthermore, we will highlight recent findings that specialized pathogenic bacteria utilize the adhesin-based interaction to diffuse the short-range messenger molecule nitric oxide into the host tissue. While anti-adhesive strategies to disrupt the initial bacterial attachment have not yet translated into medical applications, the ability to interfere with the microscale communication emanating on the host side provides an unconventional approach for preventing infectious diseases.
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17
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Laabei M, Colineau L, Bettoni S, Maziarz K, Ermert D, Riesbeck K, Ram S, Blom AM. Antibacterial Fusion Proteins Enhance Moraxella catarrhalis Killing. Front Immunol 2020; 11:2122. [PMID: 32983170 PMCID: PMC7492680 DOI: 10.3389/fimmu.2020.02122] [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: 04/04/2020] [Accepted: 08/05/2020] [Indexed: 01/10/2023] Open
Abstract
Moraxella catarrhalis is a human-specific commensal of the respiratory tract and an opportunistic pathogen. It is one of the leading cause of otitis media in children and of acute exacerbations in patients with chronic obstructive pulmonary disease, resulting in significant morbidity and economic burden. Vaccines and new immunotherapeutic strategies to treat this emerging pathogen are needed. Complement is a key component of innate immunity that mediates the detection, response, and subsequent elimination of invading pathogens. Many pathogens including M. catarrhalis have evolved complement evasion mechanisms, which include the binding of human complement inhibitors such as C4b-binding protein (C4BP) and Factor H (FH). Inhibiting C4BP and FH acquisition by M. catarrhalis may provide a novel therapeutic avenue to treat infections. To achieve this, we created two chimeric proteins that combined the Moraxella-binding domains of C4BP and FH fused to human immunoglobulin Fcs: C4BP domains 1 and 2 and FH domains 6 and 7 fused to IgM and IgG Fc, respectively. As expected, FH6-7/IgG displaced FH from the bacterial surface while simultaneously activating complement via Fc-C1q interactions, together increasing pathogen elimination. C4BP1-2/IgM also increased serum killing of the bacteria through enhanced complement deposition, but did not displace C4BP from the surface of M. catarrhalis. These Fc fusion proteins could act as anti-infective immunotherapies. Many microbes bind the complement inhibitors C4BP and FH through the same domains as M. catarrhalis, therefore these Fc fusion proteins may be promising candidates as adjunctive therapy against many different drug-resistant pathogens.
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Affiliation(s)
- Maisem Laabei
- Division of Medical Protein Chemistry, Department of Translational Medicine, Faculty of Medicine, Lund University, Malmö, Sweden.,Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Lucie Colineau
- Division of Medical Protein Chemistry, Department of Translational Medicine, Faculty of Medicine, Lund University, Malmö, Sweden
| | - Serena Bettoni
- Division of Medical Protein Chemistry, Department of Translational Medicine, Faculty of Medicine, Lund University, Malmö, Sweden
| | - Karolina Maziarz
- Division of Medical Protein Chemistry, Department of Translational Medicine, Faculty of Medicine, Lund University, Malmö, Sweden
| | - David Ermert
- Division of Medical Protein Chemistry, Department of Translational Medicine, Faculty of Medicine, Lund University, Malmö, Sweden
| | - Kristian Riesbeck
- Clinical Microbiology, Department of Translational Medicine, Faculty of Medicine, Lund University, Malmö, Sweden
| | - Sanjay Ram
- Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, MA, United States
| | - Anna M Blom
- Division of Medical Protein Chemistry, Department of Translational Medicine, Faculty of Medicine, Lund University, Malmö, Sweden
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18
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Khalil HS, Øgaard J, Leo JC. Coaggregation properties of trimeric autotransporter adhesins. Microbiologyopen 2020; 9:e1109. [PMID: 32864901 PMCID: PMC7568254 DOI: 10.1002/mbo3.1109] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 07/24/2020] [Accepted: 07/30/2020] [Indexed: 12/19/2022] Open
Abstract
Trimeric autotransporter adhesins (TAAs) comprise a group of virulence‐related proteins in Gram‐negative bacteria. Members of this family bind to extracellular matrix components such as collagen and fibronectin, but also they exhibit several other functions, such as conferring serum resistance and autoaggregation. Autoaggregation promoted by TAAs is homotypic and mediated by the sticky, globular head domains of these lollipop‐like molecules. However, whether TAAs mediate heterotypic interactions (i.e., coaggregation) has not been studied. To address this question, we investigated the coaggregation of two model TAA groups: YadA from the enteropathogenic Yersiniae and the immunoglobulin‐binding Eib proteins from Escherichia coli. To study TAA coaggregation, we coexpressed a fluorescent label together with a particular TAA and followed the aggregative interactions using fluorescence microscopy and quantified the interactions using a novel script implemented in Fiji. Our results show that there is coaggregation between some populations expressing different TAAs, which can be explained by relatively high sequence similarity between the interacting TAAs. Generally, the level of coaggregation correlated with the sequence similarity. However, some TAAs did not interact despite high sequence similarity, showing exclusion of bacteria producing a noncompatible TAA. These data demonstrate that TAAs can mediate bacterial coaggregation, but in some cases prevent coaggregation of bacteria with disparate TAAs. Our results have implications for the ecology of TAA‐producing bacteria, where coaggregation may promote co‐operation whereas exclusion might be an indication of competition.
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Affiliation(s)
- Hawzeen S Khalil
- Section for Evolution and Genetics, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Jonas Øgaard
- Research Institute of Internal Medicine, Oslo University Hospital Rikshospitalet, Oslo, Norway
| | - Jack C Leo
- Section for Evolution and Genetics, Department of Biosciences, University of Oslo, Oslo, Norway.,Antimicrobial Resistance, Omics and Microbiota Group, Department of Biosciences, School of Science and Technology, Nottingham Trent University, Nottingham, UK
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19
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Clawson ML, Schuller G, Dickey AM, Bono JL, Murray RW, Sweeney MT, Apley MD, DeDonder KD, Capik SF, Larson RL, Lubbers BV, White BJ, Blom J, Chitko-McKown CG, Brichta-Harhay DM, Smith TPL. Differences between predicted outer membrane proteins of genotype 1 and 2 Mannheimia haemolytica. BMC Microbiol 2020; 20:250. [PMID: 32787780 PMCID: PMC7424683 DOI: 10.1186/s12866-020-01932-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 07/29/2020] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Mannheimia haemolytica strains isolated from North American cattle have been classified into two genotypes (1 and 2). Although members of both genotypes have been isolated from the upper and lower respiratory tracts of cattle with or without bovine respiratory disease (BRD), genotype 2 strains are much more frequently isolated from diseased lungs than genotype 1 strains. The mechanisms behind the increased association of genotype 2 M. haemolytica with BRD are not fully understood. To address that, and to search for interventions against genotype 2 M. haemolytica, complete, closed chromosome assemblies for 35 genotype 1 and 34 genotype 2 strains were generated and compared. Searches were conducted for the pan genome, core genes shared between the genotypes, and for genes specific to either genotype. Additionally, genes encoding outer membrane proteins (OMPs) specific to genotype 2 M. haemolytica were identified, and the diversity of their protein isoforms was characterized with predominantly unassembled, short-read genomic sequences for up to 1075 additional strains. RESULTS The pan genome of the 69 sequenced M. haemolytica strains consisted of 3111 genes, of which 1880 comprised a shared core between the genotypes. A core of 112 and 179 genes or gene variants were specific to genotype 1 and 2, respectively. Seven genes encoding predicted OMPs; a peptidase S6, a ligand-gated channel, an autotransporter outer membrane beta-barrel domain-containing protein (AOMB-BD-CP), a porin, and three different trimeric autotransporter adhesins were specific to genotype 2 as their genotype 1 homologs were either pseudogenes, or not detected. The AOMB-BD-CP gene, however, appeared to be truncated across all examined genotype 2 strains and to likely encode dysfunctional protein. Homologous gene sequences from additional M. haemolytica strains confirmed the specificity of the remaining six genotype 2 OMP genes and revealed they encoded low isoform diversity at the population level. CONCLUSION Genotype 2 M. haemolytica possess genes encoding conserved OMPs not found intact in more commensally prone genotype 1 strains. Some of the genotype 2 specific genes identified in this study are likely to have important biological roles in the pathogenicity of genotype 2 M. haemolytica, which is the primary bacterial cause of BRD.
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Affiliation(s)
- Michael L Clawson
- United States Department of Agriculture, Genetics, Breeding, and Animal Health Research Unit, Agricultural Research Service, U.S. Meat Animal Research Center, Clay Center, NE, USA.
| | - Gennie Schuller
- United States Department of Agriculture, Genetics, Breeding, and Animal Health Research Unit, Agricultural Research Service, U.S. Meat Animal Research Center, Clay Center, NE, USA
| | - Aaron M Dickey
- United States Department of Agriculture, Genetics, Breeding, and Animal Health Research Unit, Agricultural Research Service, U.S. Meat Animal Research Center, Clay Center, NE, USA
| | - James L Bono
- United States Department of Agriculture, Genetics, Breeding, and Animal Health Research Unit, Agricultural Research Service, U.S. Meat Animal Research Center, Clay Center, NE, USA
| | | | | | | | - Keith D DeDonder
- Veterinary and Biomedical Research Center, Inc, Manhattan, KS, USA
| | - Sarah F Capik
- Texas A&M AgriLife Research, Texas A&M University System, Amarillo, TX, USA
- Department of Veterinary Pathobiology, Texas A&M College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA
| | | | | | | | - Jochen Blom
- Justus-Liebig-University Giessen, Giessen, Hesse, Germany
| | - Carol G Chitko-McKown
- United States Department of Agriculture, Genetics, Breeding, and Animal Health Research Unit, Agricultural Research Service, U.S. Meat Animal Research Center, Clay Center, NE, USA
| | - Dayna M Brichta-Harhay
- United States Department of Agriculture, Genetics, Breeding, and Animal Health Research Unit, Agricultural Research Service, U.S. Meat Animal Research Center, Clay Center, NE, USA
| | - Timothy P L Smith
- United States Department of Agriculture, Genetics, Breeding, and Animal Health Research Unit, Agricultural Research Service, U.S. Meat Animal Research Center, Clay Center, NE, USA
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20
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The Bartonella autotransporter BafA activates the host VEGF pathway to drive angiogenesis. Nat Commun 2020; 11:3571. [PMID: 32678094 PMCID: PMC7366657 DOI: 10.1038/s41467-020-17391-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 06/26/2020] [Indexed: 12/29/2022] Open
Abstract
Pathogenic bacteria of the genus Bartonella can induce vasoproliferative lesions during infection. The underlying mechanisms are unclear, but involve secretion of an unidentified mitogenic factor. Here, we use functional transposon-mutant screening in Bartonella henselae to identify such factor as a pro-angiogenic autotransporter, called BafA. The passenger domain of BafA induces cell proliferation, tube formation and sprouting of microvessels, and drives angiogenesis in mice. BafA interacts with vascular endothelial growth factor (VEGF) receptor-2 and activates the downstream signaling pathway, suggesting that BafA functions as a VEGF analog. A BafA homolog from a related pathogen, Bartonella quintana, is also functional. Our work unveils the mechanistic basis of vasoproliferative lesions observed in bartonellosis, and we propose BafA as a key pathogenic factor contributing to bacterial spread and host adaptation. Pathogenic bacteria of the genus Bartonella can induce vasoproliferative lesions during infection. Here, Tsukamoto et al. show that this effect is caused by a secreted protein that induces cell proliferation and angiogenesis by acting as an analog of the host’s vascular endothelial growth factor (VEGF).
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21
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Kiessling AR, Malik A, Goldman A. Recent advances in the understanding of trimeric autotransporter adhesins. Med Microbiol Immunol 2020; 209:233-242. [PMID: 31865405 PMCID: PMC7247746 DOI: 10.1007/s00430-019-00652-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 11/30/2019] [Indexed: 01/01/2023]
Abstract
Adhesion is the initial step in the infection process of gram-negative bacteria. It is usually followed by the formation of biofilms that serve as a hub for further spread of the infection. Type V secretion systems engage in this process by binding to components of the extracellular matrix, which is the first step in the infection process. At the same time they provide protection from the immune system by either binding components of the innate immune system or by establishing a physical layer against aggressors. Trimeric autotransporter adhesins (TAAs) are of particular interest in this family of proteins as they possess a unique structural composition which arises from constraints during translocation. The sequence of individual domains can vary dramatically while the overall structure can be very similar to one another. This patchwork approach allows researchers to draw conclusions of the underlying function of a specific domain in a structure-based approach which underscores the importance of solving structures of yet uncharacterized TAAs and their individual domains to estimate the full extent of functions of the protein a priori. Here, we describe recent advances in understanding the translocation process of TAAs and give an overview of structural motifs that are unique to this class of proteins. The role of BpaC in the infection process of Burkholderia pseudomallei is highlighted as an exceptional example of a TAA being at the centre of infection initiation.
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Affiliation(s)
- Andreas R. Kiessling
- Astbury Centre for Structural Molecular Biology, School of Biomedical Science, University of Leeds, Leeds, LS2 9JT England, UK
| | - Anchal Malik
- Astbury Centre for Structural Molecular Biology, School of Biomedical Science, University of Leeds, Leeds, LS2 9JT England, UK
| | - Adrian Goldman
- Astbury Centre for Structural Molecular Biology, School of Biomedical Science, University of Leeds, Leeds, LS2 9JT England, UK
- Faculty of Biological and Environmental Sciences, University of Helsinki, FIN-0014 Helsinki, Finland
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22
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Byvalov AA, Konyshev IV. Yersinia pseudotuberculosis-derived adhesins. RUSSIAN JOURNAL OF INFECTION AND IMMUNITY 2019. [DOI: 10.15789/2220-7619-2019-3-4-437-448] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Around fifteen surface components referred to adhesins have been identified in Yersinia pseudotuberculosis combining primarily microbiological, molecular and genetic, as well as immunochemical and biophysical methods. Y. pseudotuberculosis-derived adhesins vary in structure and chemical composition but they are mainly presented by protein molecules. Some of them were shown to participate not only in adhesive but in other pathogen-related physiological functions in the host-parasite interplay. Adhesins can mediate bacterial adhesion to eukaryotic cell either directly or via the extracellular matrix components. These adhesion molecules are encoded by chromosomal DNA excepting YadA protein which gene is located in the calcium-dependence plasmid pYV common for pathogenic yersisniae. An optimum temperature for adhesin biosynthesis is located close to the body temperature of warm-blooded animals; however, at low temperature only invasin InvA, full-length smooth lipopolysaccharide and porin OmpF are produced in Y. pseudotuberculosis. Several adhesins (Psa, InvA) can be expressed at low pH (corresponds to intracellular content), thereby defining pathogenic yersiniae as facultative intracellular parasites. Three human Yersinia genus pathogens differ by ability to produce adhesins. Y. pseudotuberculosis adherence to host cells or extracellular matrix components is determined by a cumulative adhesion-based activity, which expression depends on chemical composition and physicochemical environmental conditions. It’s proposed that at the initial stage of infectious process adherence of Y. pseudotuberculosis to intestinal epithelium is mediated by InvA protein and “smooth” LPS form. These adhesins are produced in bacterial cells at low (lower than 30°С) temperature occurring in environment from which a pathogen invades into the host. At later stages of pathogenesis, after penetrating through intestinal epithelium, bacterial cells produce other adhesins, which promote survival and dissemination primarily into the mesenteric lymph nodes and, possibly, liver and spleen. At later stages of pathogenesis, after penetrating through intestinal epithelium, bacterial cells produce other adhesins, which promote survival and dissemination primarily into the mesenteric lymph nodes and, perhaps, liver and spleen. Qualitative and quantitative spectrum of Y. pseudotuberculosis adhesins is determined by environmental parameters (intercellular space, intracellular content within the diverse eukaryotic cells).
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Pierce into the Native Structure of Ata, a Trimeric Autotransporter of Acinetobacter baumannii ATCC 17978. Int J Pept Res Ther 2019. [DOI: 10.1007/s10989-019-09920-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Interactions between the Trimeric Autotransporter Adhesin EmaA and Collagen Revealed by Three-Dimensional Electron Tomography. J Bacteriol 2019; 201:JB.00297-19. [PMID: 31160398 DOI: 10.1128/jb.00297-19] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 05/24/2019] [Indexed: 11/20/2022] Open
Abstract
Bacterial adhesion to host tissues is considered the first and critical step of microbial infection. The extracellular matrix protein adhesin A (EmaA) is a collagen-binding adhesin of the periodontal pathogen Aggregatibacter actinomycetemcomitans Three 202-kDa EmaA monomers form antenna-like structures on the bacterial surface with the functional domain located at the apical end. The structure of the 30-nm functional domain has been determined by three-dimensional (3D) electron tomography and subvolume averaging. The region exhibits a complex architecture composed of three subdomains (SI to SIII) and a linker between subdomains SII and SIII. However, the molecular interaction between the adhesin receptor complexes has yet to be revealed. This study provides the first detailed 3D structure of reconstituted EmaA/collagen complexes obtained using 3D electron tomography and image processing techniques. The observed interactions of EmaA with collagen were not to whole, intact fibrils, but rather to individual collagen triple helices dissociated from the fibrils. The majority of the contacts with the EmaA functional domain encompassed subdomains SII and SIII and in some cases the tip of the apical domain, involving SI. These data suggest a multipronged mechanism for the interaction of Gram-negative bacteria with collagen.IMPORTANCE Bacterial adhesion is a crucial step for bacterial colonization and infection. In recent years, the number of antibiotic-resistant strains has dramatically increased; therefore, there is a need to search for novel antimicrobial agents. Thus, great efforts are being devoted to develop a clear understanding of the bacterial adhesion mechanism for preventing infections. In host/pathogen interactions, once repulsive forces are overcome, adhesins recognize and tightly bind to specific receptors on the host cell or tissue components. Here, we present the first 3D structure of the interaction between the collagen-binding adhesin EmaA and collagen, which is critical for the development of endocarditis in humans.
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Ohara Y, Yoshimoto S, Hori K. Control of AtaA-mediated bacterial immobilization by casein hydrolysates. J Biosci Bioeng 2019; 128:544-550. [PMID: 31208800 DOI: 10.1016/j.jbiosc.2019.04.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 04/16/2019] [Accepted: 04/20/2019] [Indexed: 11/27/2022]
Abstract
Acinetobacter sp. Tol 5 exhibits an autoagglutinating nature and high adhesiveness to various abiotic surfaces through its bacterionanofiber protein AtaA. We have developed new bacterial immobilization methods utilizing the high adhesiveness of AtaA. We previously reported that salt is essential for the adhesiveness of AtaA. In the current study, we unexpectedly found that Tol 5 cells were not immobilized onto polyurethane foam support during growth in LB medium although AtaA was properly expressed and displayed onto the cell surface. The adhesion of Tol 5 resting cells was not affected by sugars but drastically inhibited by yeast extract and casein hydrolysates such as tryptone and casamino acids technical grade (CA-T). Some amino acids, which are major components of CA-T, partially inhibited the adhesion of Tol 5 cells. Experimental results suggested that oligopeptides might effectively inhibit the cell adhesion. Immobilized cells onto the support through AtaA were detached in CA-T solution. Also, the detached cells could be re-immobilized onto the support without impairing of their adhesiveness by replacing CA-T solution to a basal salt medium. Microscopic observation revealed that breaking of AtaA-mediated cell-cell interaction is important for the detachment of Tol 5 cells from the support. CA-T also inhibited AtaA-mediated autoagglutination and dispersed cell clumps through AtaA. This is the first report on adhesion inhibitors against AtaA and suggests that casein hydrolysates like CA-T would be a powerful tool for controlling AtaA-mediated bacterial immobilization.
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Affiliation(s)
- Yuki Ohara
- Department of Biomolecular Engineering, Graduate School of Engineering, Nagoya University, Nagoya, 464-8603 Aichi, Japan
| | - Shogo Yoshimoto
- Department of Biomolecular Engineering, Graduate School of Engineering, Nagoya University, Nagoya, 464-8603 Aichi, Japan; Venture Business Laboratory (VBL), Nagoya University, Nagoya, 464-0814 Aichi, Japan
| | - Katsutoshi Hori
- Department of Biomolecular Engineering, Graduate School of Engineering, Nagoya University, Nagoya, 464-8603 Aichi, Japan.
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Structural diversity of coiled coils in protein fibers of the bacterial cell envelope. Int J Med Microbiol 2019; 309:351-358. [PMID: 31182277 DOI: 10.1016/j.ijmm.2019.05.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 04/14/2019] [Accepted: 05/31/2019] [Indexed: 02/06/2023] Open
Abstract
The cell envelope of bacteria shows great diversity in architecture and composition, to a large extent due to its proteome. Proteins localized to the cell envelope, whether integrally embedded in the membrane, membrane-anchored, or peripherally associated as part of a macromolecular complex, often form elongated fibers, in which coiled coils represent a prominent structural element. These coiled-coil segments show a surprising degree of structural variability, despite being shaped by a small number of simple biophysical rules, foremost being their geometry of interaction referred to as 'knobs-into-holes'. Here we will review this diversity, particularly as it has emerged over the last decade.
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Meuskens I, Saragliadis A, Leo JC, Linke D. Type V Secretion Systems: An Overview of Passenger Domain Functions. Front Microbiol 2019; 10:1163. [PMID: 31214135 PMCID: PMC6555100 DOI: 10.3389/fmicb.2019.01163] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 05/07/2019] [Indexed: 12/12/2022] Open
Abstract
Bacteria secrete proteins for different purposes such as communication, virulence functions, adhesion to surfaces, nutrient acquisition, or growth inhibition of competing bacteria. For secretion of proteins, Gram-negative bacteria have evolved different secretion systems, classified as secretion systems I through IX to date. While some of these systems consist of multiple proteins building a complex spanning the cell envelope, the type V secretion system, the subject of this review, is rather minimal. Proteins of the Type V secretion system are often called autotransporters (ATs). In the simplest case, a type V secretion system consists of only one polypeptide chain with a β-barrel translocator domain in the membrane, and an extracellular passenger or effector region. Depending on the exact domain architecture of the protein, type V secretion systems can be further separated into sub-groups termed type Va through e, and possibly another recently identified subtype termed Vf. While this classification works well when it comes to the architecture of the proteins, this is not the case for the function(s) of the secreted passenger. In this review, we will give an overview of the functions of the passengers of the different AT classes, shedding more light on the variety of functions carried out by type V secretion systems.
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Affiliation(s)
| | | | | | - Dirk Linke
- Department of Biosciences, Section for Genetics and Evolutionary Biology, University of Oslo, Oslo, Norway
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Saragliadis A, Linke D. Assay development for the discovery of small-molecule inhibitors of YadA adhesion to collagen. ACTA ACUST UNITED AC 2019; 5:100025. [PMID: 32743141 PMCID: PMC7388967 DOI: 10.1016/j.tcsw.2019.100025] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 05/02/2019] [Accepted: 05/02/2019] [Indexed: 02/01/2023]
Abstract
We set out to develop scalable assays to measure bacterial adhesion to mammalian extracellular matrix proteins, with the aim to perform high-throughput screening for inhibitors. Our model system is the trimeric autotransporter adhesin YadA from Yersinia enterocolitica that binds to collagen. Using bacterial cells expressing GFP under an inducible promotor, and co-expressing the adhesin of choice, we were able to establish a 384-well plate-based assay that allowed us to screen 28,000 compounds in 8 days (3520 compounds per day). We have collected all parameters that were essential in assay development, and describe how they can be tuned for improved performance. Out of 28,000 compounds, 5 compounds showed significant inhibitory activity, measured as loss of fluorescence compared to control wells. Our assay is easy to scale up, and can be adopted to different ECM component/Adhesin combinations. Alternatively, bacterial pathogens (harboring deletion mutants of adhesins compared to wildtype) could be used directly in the same assay if they express GFP as a reporter at high levels.
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Affiliation(s)
- Athanasios Saragliadis
- 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
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Okaro U, Green R, Mohapatra S, Anderson B. The trimeric autotransporter adhesin BadA is required for in vitro biofilm formation by Bartonella henselae. NPJ Biofilms Microbiomes 2019; 5:10. [PMID: 30886729 PMCID: PMC6418236 DOI: 10.1038/s41522-019-0083-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 02/01/2019] [Indexed: 01/10/2023] Open
Abstract
Bartonella henselae (Bh) is a Gram-negative rod transmitted to humans by a scratch from the common house cat. Infection of humans with Bh can result in a range of clinical diseases including lymphadenopathy observed in cat-scratch disease and more serious disease from persistent bacteremia. It is a common cause of blood-culture negative endocarditis as the bacterium is capable of growing as aggregates, and forming biofilms on infected native and prosthetic heart valves. The aggregative growth requires a trimeric autotransporter adhesin (TAA) called Bartonella adhesin A (BadA). TAAs are found in all Bartonella species and many other Gram-negative bacteria. Using Bh Houston-1, Bh Houston-1 ∆badA and Bh Houston-1 ∆badA/pNS2PTrc badA (a partial complement of badA coding for a truncated protein of 741 amino acid residues), we analyze the role of BadA in adhesion and biofilm formation. We also investigate the role of environmental factors such as temperature on badA expression and biofilm formation. Real-time cell adhesion monitoring and electron microscopy show that Bh Houston-1 adheres and forms biofilm more efficiently than the Bh Houston-1 ∆badA. Deletion of the badA gene significantly decreases adhesion, the first step in biofilm formation in vitro, which is partially restored in Bh Houston-1 ∆badA/pNS2PTrc badA. The biofilm formed by Bh Houston-1 includes polysaccharides, proteins, and DNA components and is susceptible to enzymatic degradation of these components. Furthermore, both pH and temperature influence both badA expression and biofilm formation. We conclude that BadA is required for optimal adhesion, agglutination and biofilm formation.
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Affiliation(s)
- Udoka Okaro
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Ryan Green
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Subhra Mohapatra
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Burt Anderson
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, USA.
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Inhibitory effects of polysorbate 80 on MRSA biofilm formed on different substrates including dermal tissue. Sci Rep 2019; 9:3128. [PMID: 30816342 PMCID: PMC6395670 DOI: 10.1038/s41598-019-39997-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 02/04/2019] [Indexed: 12/04/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) forms biofilms on necrotic tissues and medical devices, and causes persistent infections. Surfactants act on biofilms, but their mode of action is still unknown. If used in the clinic, cytotoxicity in tissues should be minimized. In this study, we investigated the inhibitory effect of four different surfactants on MRSA biofilm formation, and found that a nonionic surfactant, polysorbate 80 (PS80), was the most suitable. The biofilm inhibitory effects resulted from the inhibition of bacterial adhesion to substrates rather than biofilm disruption, and the effective dose was less cytotoxic for 3T3 fibroblasts. However, the effects were substrate-dependent: positive for plastic, silicon, and dermal tissues, but negative for stainless-steel. These results indicate that PS80 is effective for prevention of biofilms formed by MRSA on tissues and foreign bodies. Therefore, PS80 could be used in medical practice as a washing solution for wounds and/or pretreatment of indwelling catheters.
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Fingas F, Volke D, Hassert R, Fornefett J, Funk S, Baums CG, Hoffmann R. Sensitive and immunogen-specific serological detection of Rodentibacter pneumotropicus infections in mice. BMC Microbiol 2019; 19:43. [PMID: 30777007 PMCID: PMC6380038 DOI: 10.1186/s12866-019-1417-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 02/08/2019] [Indexed: 02/02/2023] Open
Abstract
Background Rodentibacter (R.) pneumotropicus colonizes the respiratory and urogenital tracts of laboratory mice with a reported moderate serological prevalence from 4 to 13%. Thus, regular tests to identify this pathogen in mice are recommended for animal facilities. However, a recent study indicated that current serological assays are partly insensitive, as C57BL/6 and BALB/c mice infected with R. pneumotropicus were incorrectly screened as seronegative. Results Here, we report a systematic analysis of protein and lipopolysaccharides antigens by immunoblot and ELISA that allowed establishing a sensitive test system able to differentiate between R. pneumotropicus and the closely related species R. heylii. Furthermore, the main immunogen, designated as ‘characteristic antigen for Rodentibacter of laboratory origin 1’ (CARLO-1), was identified by two-dimensional gel electrophoresis followed by immunoblot and tandem mass spectrometry in a preparation of outer membrane proteins. An indirect ELISA relying on the recombinantly expressed protein provided high sensitivity, specificity, and selectivity. The corresponding carlo1 gene was highly conserved (> 97%) among 21 isolates of R. pneumotropicus and R. heylii. Conclusion The newly identified protein CARLO-1 is well suited for the sensitive and specific serological detection of Rodentibacter infections in mice. Indirect differentiation of R. pneumotropicus and R. heylii infections may be possible using an ELISA based on a whole-cell antigen preparation. All four established ELISA systems using a whole-cell preparation, lipopolysaccharides, outer-membrane proteins and protein CARLO-1 as antigen, respectively, outperformed a commercial ELISA in terms of sensitivity. Electronic supplementary material The online version of this article (10.1186/s12866-019-1417-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Felix Fingas
- Institute of Bioanalytical Chemistry, Faculty of Chemistry and Mineralogy, Universität Leipzig, Leipzig, Germany.,GVG Diagnostics GmbH, Leipzig, Germany
| | - Daniela Volke
- Institute of Bioanalytical Chemistry, Faculty of Chemistry and Mineralogy, Universität Leipzig, Leipzig, Germany.,Center for Biotechnology and Biomedicine, Universität Leipzig, Leipzig, Germany
| | - Rayk Hassert
- Institute of Bioanalytical Chemistry, Faculty of Chemistry and Mineralogy, Universität Leipzig, Leipzig, Germany.,Center for Biotechnology and Biomedicine, Universität Leipzig, Leipzig, Germany
| | - Juliane Fornefett
- Institute for Bacteriology and Mycology, Faculty of Veterinary Medicine, Universität Leipzig, Leipzig, Germany
| | - Sophie Funk
- Institute for Bacteriology and Mycology, Faculty of Veterinary Medicine, Universität Leipzig, Leipzig, Germany
| | - Christoph Georg Baums
- Center for Biotechnology and Biomedicine, Universität Leipzig, Leipzig, Germany.,Institute for Bacteriology and Mycology, Faculty of Veterinary Medicine, Universität Leipzig, Leipzig, Germany
| | - Ralf Hoffmann
- Institute of Bioanalytical Chemistry, Faculty of Chemistry and Mineralogy, Universität Leipzig, Leipzig, Germany. .,Center for Biotechnology and Biomedicine, Universität Leipzig, Leipzig, Germany. .,Biotechnologisch-Biomedizinisches Zentrum, Universität Leipzig, Deutscher Platz 5, 04103, Leipzig, Germany.
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Chauhan N, Hatlem D, Orwick-Rydmark M, Schneider K, Floetenmeyer M, van Rossum B, Leo JC, Linke D. Insights into the autotransport process of a trimeric autotransporter, Yersinia Adhesin A (YadA). Mol Microbiol 2019; 111:844-862. [DOI: 10.1111/mmi.14195] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Nandini Chauhan
- Department of Biosciences; University of Oslo; Blindernveien 31 0371 Oslo Norway
- Max Planck Institute for Developmental Biology, Department 1; 72076 Tübingen Germany
| | - Daniel Hatlem
- Department of Biosciences; University of Oslo; Blindernveien 31 0371 Oslo Norway
| | | | - Kenneth Schneider
- Department of Biosciences; University of Oslo; Blindernveien 31 0371 Oslo Norway
| | - Matthias Floetenmeyer
- Max Planck Institute for Developmental Biology, Department 1; 72076 Tübingen Germany
- The Centre for Microscopy and Microanalysis, The University of Queensland; 4072 St. Lucia Queensland Australia
| | - Barth van Rossum
- Forschungsinstitut für Molekulare Pharmakologie; Department of NMR-Supported Structural Biology; Berlin Germany
| | - Jack C. Leo
- Department of Biosciences; University of Oslo; Blindernveien 31 0371 Oslo Norway
- Max Planck Institute for Developmental Biology, Department 1; 72076 Tübingen Germany
| | - Dirk Linke
- Department of Biosciences; University of Oslo; Blindernveien 31 0371 Oslo Norway
- Max Planck Institute for Developmental Biology, Department 1; 72076 Tübingen Germany
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Schulte M, Sterzenbach T, Miskiewicz K, Elpers L, Hensel M, Hansmeier N. A versatile remote control system for functional expression of bacterial virulence genes based on the tetA promoter. Int J Med Microbiol 2019; 309:54-65. [DOI: 10.1016/j.ijmm.2018.11.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 10/21/2018] [Accepted: 11/14/2018] [Indexed: 11/16/2022] Open
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A Nonfimbrial Adhesin of Aggregatibacter actinomycetemcomitans Mediates Biofilm Biogenesis. Infect Immun 2018; 87:IAI.00704-18. [PMID: 30297525 DOI: 10.1128/iai.00704-18] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 10/03/2018] [Indexed: 11/20/2022] Open
Abstract
Periodontitis is an inflammatory disease caused by polymicrobial biofilms. The periodontal pathogen Aggregatibacter actinomycetemcomitans displays two proteinaceous surface structures, the fimbriae and the nonfimbrial extracellular matrix binding protein A (EmaA), as observed by electron microscopy. Fimbriae participate in biofilm biogenesis and the EmaA adhesins mediate collagen binding. However, in the absence of fimbriae, A. actinomycetemcomitans still retains the potential to form robust biofilms, suggesting that other surface macromolecules participate in biofilm development. Here, isogenic mutant strains lacking EmaA structures, but still expressing fimbriae, were observed to have reduced biofilm potential. In strains lacking both EmaA and fimbriae, biofilm mass was reduced by 80%. EmaA enhanced biofilm formation in different strains, independent of the fimbriation state or serotype. Confocal microscopy revealed differences in cell density within microcolonies between the EmaA positive and mutant strains. EmaA-mediated biofilm formation was found to be independent of the glycosylation state and the precise three-dimensional conformation of the protein, and thus this function is uncorrelated with collagen binding activity. The data suggest that EmaA is a multifunctional adhesin that utilizes different mechanisms to enhance bacterial binding to collagen and to enhance biofilm formation, both of which are important for A. actinomycetemcomitans colonization and subsequent infection.
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Deng H, Pang Q, Zhao B, Vayssier-Taussat M. Molecular Mechanisms of Bartonella and Mammalian Erythrocyte Interactions: A Review. Front Cell Infect Microbiol 2018; 8:431. [PMID: 30619777 PMCID: PMC6299047 DOI: 10.3389/fcimb.2018.00431] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 11/30/2018] [Indexed: 12/18/2022] Open
Abstract
Bartonellosis is an infectious disease caused by Bartonella species that are distributed worldwide with animal and public health impact varying according to Bartonella species, infection phase, immunological characteristics, and geographical region. Bartonella is widely present in various mammals including cats, rodents, ruminants, and humans. At least 13 Bartonella species or subspecies are zoonotic. Each species has few reservoir animals in which it is often asymptomatic. Bartonella infection may lead to various clinical symptoms in humans. As described in the B.tribocorum-rat model, when Bartonella was seeded into the blood stream, they could escape immunity, adhered to and invaded host erythrocytes. They then replicated and persisted in the infected erythrocytes for several weeks. This review summarizes the current knowledge of how Bartonella prevent phagocytosis and complement activation, what pathogenesis factors are involved in erythrocyte adhesion and invasion, and how Bartonella could replicate and persist in mammalian erythrocytes. Current advances in research will help us to decipher molecular mechanisms of interactions between Bartonella and mammalian erythrocytes and may help in the development of biological strategies for the prevention and control of bartonellosis.
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Affiliation(s)
- Hongkuan Deng
- School of Life Sciences, Shandong University of Technology, Zibo, China
| | - Qiuxiang Pang
- School of Life Sciences, Shandong University of Technology, Zibo, China
| | - Bosheng Zhao
- School of Life Sciences, Shandong University of Technology, Zibo, China
| | - Muriel Vayssier-Taussat
- UMR BIPAR, INRA, ANSES, École Nationale Vétérinaire d'Alfort, Université Paris-Est Créteil Val-de-Marne, Maisons-Alfort, France
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Nakatani H, Kanie J, Hori K. On‐fiber display of a functional peptide at sites distant from the cell surface using a long bacterionanofiber of a trimeric autotransporter adhesin. Biotechnol Bioeng 2018; 116:239-249. [DOI: 10.1002/bit.26857] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 10/20/2018] [Accepted: 10/30/2018] [Indexed: 01/08/2023]
Affiliation(s)
- Hajime Nakatani
- Department of Biomolecular EngineeringGraduate School of Engineering, Nagoya University, Furo‐cho, Chikusa‐kuNagoya Japan
| | - Junichi Kanie
- Department of Biomolecular EngineeringGraduate School of Engineering, Nagoya University, Furo‐cho, Chikusa‐kuNagoya Japan
| | - Katsutoshi Hori
- Department of Biomolecular EngineeringGraduate School of Engineering, Nagoya University, Furo‐cho, Chikusa‐kuNagoya Japan
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Paulsson M, Riesbeck K. How bacteria hack the matrix and dodge the bullets of immunity. Eur Respir Rev 2018; 27:27/148/180018. [PMID: 29950304 DOI: 10.1183/16000617.0018-2018] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 05/29/2018] [Indexed: 11/05/2022] Open
Abstract
Haemophilus influenzae, Moraxella catarrhalis and Pseudomonas aeruginosa are common Gram-negative pathogens associated with an array of pulmonary diseases. All three species have multiple adhesins in their outer membrane, i.e. surface structures that confer the ability to bind to surrounding cells, proteins or tissues. This mini-review focuses on proteins with high affinity for the components of the extracellular matrix such as collagen, laminin, fibronectin and vitronectin. Adhesins are not structurally related and may be lipoproteins, transmembrane porins or large protruding trimeric auto-transporters. They enable bacteria to avoid being cleared together with mucus by attaching to patches of exposed extracellular matrix, or indirectly adhering to epithelial cells using matrix proteins as bridging molecules. As more adhesins are being unravelled, it is apparent that bacterial adhesion is a highly conserved mechanism, and that most adhesins target the same regions on the proteins of the extracellular matrix. The surface exposed adhesins are prime targets for new vaccines and the interactions between proteins are often possible to inhibit with interfering molecules, e.g heparin. In conclusion, this highly interesting research field of microbiology has unravelled host-pathogen interactions with high therapeutic potential.
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Affiliation(s)
- Magnus Paulsson
- Division for Infectious Diseases, Skåne University Hospital, Lund, Sweden.,Clinical Microbiology, Dept of Translational Medicine, Faculty of Medicine, Lund University, Malmö, Sweden
| | - Kristian Riesbeck
- Clinical Microbiology, Dept of Translational Medicine, Faculty of Medicine, Lund University, Malmö, Sweden
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Immobilization of Enterobacter aerogenes by a Trimeric Autotransporter Adhesin, AtaA, and Its Application to Biohydrogen Production. Catalysts 2018. [DOI: 10.3390/catal8040159] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Biological hydrogen production by microbial cells has been extensively researched as an energy-efficient and environmentally-friendly process. In this study, we propose a fast, easy method for immobilizing Enterobacter aerogenes by expressing ataA, which encodes the adhesive protein of Acinetobacter sp. Tol 5. AtaA protein on the E. aerogenes cells carrying the ataA gene was demonstrated by immunoblotting and flow cytometry. The AtaA-producing cells exhibited stronger adherence and auto-agglutination characteristics than wild-type cells, and were successfully immobilized (at approximately 2.5 mg/cm3) on polyurethane foam. Hydrogen production from the cell-immobilized polyurethane foams was monitored in repetitive batch reactions and flow reactor studies. The total hydrogen production in triple-repetitive batch reactions reached 0.6 mol/mol glucose, and the hydrogen production rate in the flow reactor was 42 mL·h−1·L−1. The AtaA production achieved simple and immediate immobilization of E. aerogenes on the foam, enabling repetitive and continuous hydrogen production. This report newly demonstrates the production of AtaA on the cell surfaces of bacterial genera other than Acinetobacter, and can simplify and accelerate the immobilization of whole-cell catalysts.
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Antonets KS, Kliver SF, Nizhnikov AA. Exploring Proteins Containing Amyloidogenic Regions in the Proteomes of Bacteria of the Order Rhizobiales. Evol Bioinform Online 2018; 14:1176934318768781. [PMID: 29720870 PMCID: PMC5922492 DOI: 10.1177/1176934318768781] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 02/27/2018] [Indexed: 11/16/2022] Open
Abstract
Amyloids are protein fibrils with a highly ordered spatial structure called cross-β. To date, amyloids were shown to be implicated in a wide range of biological processes, both pathogenic and functional. In bacteria, functional amyloids are involved in forming biofilms, storing toxins, overcoming the surface tension, and other functions. Rhizobiales represent an economically important group of Alphaproteobacteria, various species of which are not only capable of fixing nitrogen in the symbiosis with leguminous plants but also act as the causative agents of infectious diseases in animals and plants. Here, we implemented bioinformatic screening for potentially amyloidogenic proteins in the proteomes of more than 80 species belonging to the order Rhizobiales. Using SARP (Sequence Analysis based on the Ranking of Probabilities) and Waltz bioinformatic algorithms, we identified the biological processes, where potentially amyloidogenic proteins are overrepresented. We detected protein domains and regions associated with amyloidogenic sequences in the proteomes of various Rhizobiales species. We demonstrated that amyloidogenic regions tend to occur in the membrane or extracellular proteins, many of which are involved in pathogenesis-related processes, including adhesion, assembly of flagellum, and transport of siderophores and lipopolysaccharides, and contain domains typical of the virulence factors (hemolysin, RTX, YadA, LptD); some of them (rhizobiocins, LptD) are also related to symbiosis.
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Affiliation(s)
- Kirill S Antonets
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology, St. Petersburg, Russian Federation.,Department of Genetics, St. Petersburg State University, St. Petersburg, Russian Federation
| | - Sergey F Kliver
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology, St. Petersburg, Russian Federation.,Department of Genetics, St. Petersburg State University, St. Petersburg, Russian Federation
| | - Anton A Nizhnikov
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology, St. Petersburg, Russian Federation.,Department of Genetics, St. Petersburg State University, St. Petersburg, Russian Federation
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Abstract
Many bacteria, both environmental and pathogenic, exhibit the property of autoaggregation. In autoaggregation (sometimes also called autoagglutination or flocculation), bacteria of the same type form multicellular clumps that eventually settle at the bottom of culture tubes. Autoaggregation is generally mediated by self-recognising surface structures, such as proteins and exopolysaccharides, which we term collectively as autoagglutinins. Although a widespread phenomenon, in most cases the function of autoaggregation is poorly understood, though there is evidence to show that aggregating bacteria are protected from environmental stresses or host responses. Autoaggregation is also often among the first steps in forming biofilms. Here, we review the current knowledge on autoaggregation, the role of autoaggregation in biofilm formation and pathogenesis, and molecular mechanisms leading to aggregation using specific examples.
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Affiliation(s)
- Thomas Trunk
- Bacterial Cell Surface Group, Section for Genetics and Evolutionary Biology, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Hawzeen S Khalil
- Bacterial Cell Surface Group, Section for Genetics and Evolutionary Biology, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Jack C Leo
- Bacterial Cell Surface Group, Section for Genetics and Evolutionary Biology, Department of Biosciences, University of Oslo, Oslo, Norway
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Utilization of Variant and Fusion Proteins To Functionally Map the Aggregatibacter actinomycetemcomitans Trimeric Autotransporter Protein ApiA. Infect Immun 2018; 86:IAI.00697-17. [PMID: 29229732 DOI: 10.1128/iai.00697-17] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 12/01/2017] [Indexed: 11/20/2022] Open
Abstract
The Gram-negative bacterium Aggregatibacter actinomycetemcomitans is a causative agent of localized aggressive periodontitis. Critical to its infection process is the first and essential step of attachment, which is related to the coordinated functions of surface components comprised of proteins and extracellular polysaccharides. One such protein is the outer membrane trimeric autotransporter protein ApiA, a versatile virulence factor with numerous functions, including cell binding, invasion, serum resistance, autoaggregation, and induction of cytokine release. Here we report on the use of Escherichia coli strains expressing protein variants to define the separate functions ascribed to the N terminus and those related to the C terminus. Importantly, a hybrid protein that comprised the N terminus of trimeric ApiA and the β-barrel domain of monomeric autotransporter Aae was constructed, which allowed the expression of a monomer surface-exposed domain of ApiA. Functional and phenotypic analyses demonstrated that the C terminus of ApiA forms an independent domain that is crucial for general stability and trimer formation, which appears to be associated with autoaggregation, biofilm formation, and surface expression. Importantly, the results show that the monomeric form of the N-terminal passenger domain of ApiA, while surface exposed, is sufficient for binding to buccal epithelial cells; however, it is not sufficient to allow aggregation and biofilm formation, strengthening the importance of the role of trimerization in these phenotypes.
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Abstract
Since the reclassification of the genus Bartonella in 1993, the number of species has grown from 1 to 45 currently designated members. Likewise, the association of different Bartonella species with human disease continues to grow, as does the range of clinical presentations associated with these bacteria. Among these, blood-culture-negative endocarditis stands out as a common, often undiagnosed, clinical presentation of infection with several different Bartonella species. The limitations of laboratory tests resulting in this underdiagnosis of Bartonella endocarditis are discussed. The varied clinical picture of Bartonella infection and a review of clinical aspects of endocarditis caused by Bartonella are presented. We also summarize the current knowledge of the molecular basis of Bartonella pathogenesis, focusing on surface adhesins in the two Bartonella species that most commonly cause endocarditis, B. henselae and B. quintana. We discuss evidence that surface adhesins are important factors for autoaggregation and biofilm formation by Bartonella species. Finally, we propose that biofilm formation is a critical step in the formation of vegetative masses during Bartonella-mediated endocarditis and represents a potential reservoir for persistence by these bacteria.
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Vo JL, Martínez Ortiz GC, Subedi P, Keerthikumar S, Mathivanan S, Paxman JJ, Heras B. Autotransporter Adhesins in Escherichia coli Pathogenesis. Proteomics 2017; 17. [PMID: 28665015 DOI: 10.1002/pmic.201600431] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2017] [Revised: 06/21/2017] [Indexed: 12/14/2022]
Abstract
Most bacteria produce adhesion molecules to facilitate the interaction with host cells and establish successful infections. An important group of bacterial adhesins belong to the autotransporter (AT) superfamily, the largest group of secreted and outer membrane proteins in Gram-negative bacteria. AT adhesins possess diverse functions that facilitate bacterial colonisation, survival and persistence, and as such are often associated with increased bacterial fitness and pathogenic potential. In this review, we will describe AIDA-I type AT adhesins, which comprise the biggest and most diverse group in the AT family. We will focus on Escherichia coli proteins and define general aspects of their biogenesis, distribution, structural properties and key roles in infection.
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Affiliation(s)
- Julieanne L Vo
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia
| | - Gabriela Constanza Martínez Ortiz
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia
| | - Pramod Subedi
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia
| | - Shivakumar Keerthikumar
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia
| | - Suresh Mathivanan
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia
| | - Jason J Paxman
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia
| | - Begoña Heras
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia
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Antibodies against In Vivo-Expressed Antigens Are Sufficient To Protect against Lethal Aerosol Infection with Burkholderia mallei and Burkholderia pseudomallei. Infect Immun 2017; 85:IAI.00102-17. [PMID: 28507073 DOI: 10.1128/iai.00102-17] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2017] [Accepted: 05/08/2017] [Indexed: 12/22/2022] Open
Abstract
Burkholderia mallei, a facultative intracellular bacterium and tier 1 biothreat, causes the fatal zoonotic disease glanders. The organism possesses multiple genes encoding autotransporter proteins, which represent important virulence factors and targets for developing countermeasures in pathogenic Gram-negative bacteria. In the present study, we investigated one of these autotransporters, BatA, and demonstrate that it displays lipolytic activity, aids in intracellular survival, is expressed in vivo, elicits production of antibodies during infection, and contributes to pathogenicity in a mouse aerosol challenge model. A mutation in the batA gene of wild-type strain ATCC 23344 was found to be particularly attenuating, as BALB/c mice infected with the equivalent of 80 median lethal doses cleared the organism. This finding prompted us to test the hypothesis that vaccination with the batA mutant strain elicits protective immunity against subsequent infection with wild-type bacteria. We discovered that not only does vaccination provide high levels of protection against lethal aerosol challenge with B. mallei ATCC 23344, it also protects against infection with multiple isolates of the closely related organism and causative agent of melioidosis, Burkholderia pseudomallei Passive-transfer experiments also revealed that the protective immunity afforded by vaccination with the batA mutant strain is predominantly mediated by IgG antibodies binding to antigens expressed exclusively in vivo Collectively, our data demonstrate that BatA is a target for developing medical countermeasures and that vaccination with a mutant lacking expression of the protein provides a platform to gain insights regarding mechanisms of protective immunity against B. mallei and B. pseudomallei, including antigen discovery.
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Chen B, Akusobi C, Fang X, Salmond GPC. Environmental T4-Family Bacteriophages Evolve to Escape Abortive Infection via Multiple Routes in a Bacterial Host Employing "Altruistic Suicide" through Type III Toxin-Antitoxin Systems. Front Microbiol 2017; 8:1006. [PMID: 28620370 PMCID: PMC5449768 DOI: 10.3389/fmicb.2017.01006] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 05/19/2017] [Indexed: 11/28/2022] Open
Abstract
Abortive infection is an anti-phage mechanism employed by a bacterium to initiate its own death upon phage infection. This reduces, or eliminates, production of viral progeny and protects clonal siblings in the bacterial population by an act akin to an "altruistic suicide." Abortive infection can be mediated by a Type III toxin-antitoxin system called ToxINPa consisting of an endoribonuclease toxin and RNA antitoxin. ToxINPa is a heterohexameric quaternary complex in which pseudoknotted RNA inhibits the toxicity of the toxin until infection by certain phages causes destabilization of ToxINPa, leading to bacteriostasis and, eventually, lethality. However, it is still unknown why only certain phages are able to activate ToxINPa. To try to address this issue we first introduced ToxINPa into the Gram-negative enterobacterium, Serratia sp. ATCC 39006 (S 39006) and then isolated new environmental S 39006 phages that were scored for activation of ToxINPa and abortive infection capacity. We isolated three T4-like phages from a sewage treatment outflow point into the River Cam, each phage being isolated at least a year apart. These phages were susceptible to ToxINPa-mediated abortive infection but produced spontaneous "escape" mutants that were insensitive to ToxINPa. Analysis of these resistant mutants revealed three different routes of escaping ToxINPa, namely by mutating asiA (the product of which is a phage transcriptional co-activator); by mutating a conserved, yet functionally unknown, orf84; or by deleting a 6.5-10 kb region of the phage genome. Analysis of these evolved escape mutants may help uncover the nature of the corresponding phage product(s) involved in activation of ToxINPa.
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Guérin J, Bigot S, Schneider R, Buchanan SK, Jacob-Dubuisson F. Two-Partner Secretion: Combining Efficiency and Simplicity in the Secretion of Large Proteins for Bacteria-Host and Bacteria-Bacteria Interactions. Front Cell Infect Microbiol 2017; 7:148. [PMID: 28536673 PMCID: PMC5422565 DOI: 10.3389/fcimb.2017.00148] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 04/10/2017] [Indexed: 12/31/2022] Open
Abstract
Initially identified in pathogenic Gram-negative bacteria, the two-partner secretion (TPS) pathway, also known as Type Vb secretion, mediates the translocation across the outer membrane of large effector proteins involved in interactions between these pathogens and their hosts. More recently, distinct TPS systems have been shown to secrete toxic effector domains that participate in inter-bacterial competition or cooperation. The effects of these systems are based on kin vs. non-kin molecular recognition mediated by specific immunity proteins. With these new toxin-antitoxin systems, the range of TPS effector functions has thus been extended from cytolysis, adhesion, and iron acquisition, to genome maintenance, inter-bacterial killing and inter-bacterial signaling. Basically, a TPS system is made up of two proteins, the secreted TpsA effector protein and its TpsB partner transporter, with possible additional factors such as immunity proteins for protection against cognate toxic effectors. Structural studies have indicated that TpsA proteins mainly form elongated β helices that may be followed by specific functional domains. TpsB proteins belong to the Omp85 superfamily. Open questions remain on the mechanism of protein secretion in the absence of ATP or an electrochemical gradient across the outer membrane. The remarkable dynamics of the TpsB transporters and the progressive folding of their TpsA partners at the bacterial surface in the course of translocation are thought to be key elements driving the secretion process.
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Affiliation(s)
- Jeremy Guérin
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of HealthBethesda, MD, USA
| | - Sarah Bigot
- Molecular Microbiology and Structural Biochemistry, Centre National de La Recherche Scientifique UMR 5086-Université Lyon 1, Institute of Biology and Chemistry of ProteinsLyon, France
| | - Robert Schneider
- NMR and Molecular Interactions, Université de Lille, Centre National de La Recherche Scientifique, UMR 8576-Unité de Glycobiologie Structurale et FonctionnelleLille, France
| | - Susan K Buchanan
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of HealthBethesda, MD, USA
| | - Françoise Jacob-Dubuisson
- Université de Lille, Centre National de La Recherche Scientifique, Institut National de La Santé et de La Recherche Médicale, CHU Lille, Institut Pasteur de Lille, U1019-UMR 8204-Centre d'Infection et d'Immunité de LilleLille, France
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Tsugo K, Nakamura SI, Yamanaka H, Une Y. A study on the efficacy of the recombinant Yersinia adhesin A vaccine against yersiniosis in the early phase. J Vet Med Sci 2017; 79:855-863. [PMID: 28320976 PMCID: PMC5447973 DOI: 10.1292/jvms.16-0528] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Yersinia pseudotuberculosis (Y. ptb) is a zoonotic pathogenic bacterial species of the family Enterobacteriaceae and causes yersiniosis, an acute intestinal infection in humans and animals.
Y. ptb is often implicated in lethal epidemics in zoo animals and reductions in the breeding population, but a valid prevention method has not been established. Therefore, this study aimed to develop a vaccine
for yersiniosis control. The immunogenicity of one of the adhesion factors involved in pathogenic mechanisms of Y. ptb, Yersinia adhesin A (YadA), was investigated. BALB/c mice were divided into 3
groups: in group 1, mice received insoluble recombinant YadA (rYadA) produced in genetically engineered Escherichia coli (100 µg/dose); in group 2, mice received inactivated Y.
ptb with strong expression of YadA (20 mg/dose);and in group 3, mice received phosphate-buffered saline (0.2 ml/dose). All interventions were administered subcutaneously twice at an interval of 1 week.
One week after the second administration, Y. ptb (107 cells/mouse) was inoculated orally. As a result, the survival rate was 100% in group 1, 60% in group 2, and 0% in group 3. The anti-YadA antibody
titer increased in a stepwise fashion in groups 1 and 2. The present study results suggest that rYadA shows promise as a protective antigen against yersiniosis. This study concluded that vaccination against Y. ptb
may become available as a new method to prevent lethal epidemics in animals.
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Affiliation(s)
- Kosuke Tsugo
- Laboratory of Veterinary Pathology, School of Veterinary Medicine, Azabu University, 1-17-71 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5201, Japan
| | - Shin-Ichi Nakamura
- Laboratory of Veterinary Pathology, School of Veterinary Medicine, Azabu University, 1-17-71 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5201, Japan
| | - Hiroko Yamanaka
- Laboratory of Veterinary Pathology, School of Veterinary Medicine, Azabu University, 1-17-71 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5201, Japan
| | - Yumi Une
- Laboratory of Veterinary Pathology, School of Veterinary Medicine, Azabu University, 1-17-71 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5201, Japan
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Pina-Pedrero S, Olvera À, Bensaid A. The extended leader peptide of Haemophilus parasuis trimeric autotransporters conditions their protein expression in Escherichia coli. Protein Expr Purif 2017; 133:15-24. [PMID: 28254554 DOI: 10.1016/j.pep.2017.02.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 02/09/2017] [Accepted: 02/26/2017] [Indexed: 10/20/2022]
Abstract
Trimeric autotransporters are surface-exposed proteins of Gram-negative bacteria belonging to the type V secretion system. They are involved in virulence and are targets for vaccine and diagnostic tool development, so optimal systems for their expression and purification are required. In the present study, the impact of the extended leader peptide of the Haemophilus parasuis virulence-associated trimeric autotransporters (VtaA) in its production as recombinant proteins in Escherichia coli was evaluated. The 13 genes encoding the VtaA1 to VtaA13 passenger domains of the strain Nagasaki were cloned in the pASK-IBA33plus plasmid and expressed in E. coli. Recombinant protein production was higher for truncated forms in which the entire leader peptide was deleted, and the recombinant protein accumulated in the cytoplasm of the cells. The yield of protein production of the different VtaAs was size dependent, and reached maximal amount at 2-4 h post -induction. The optimization of these conditions allowed to scale-up the production to obtain enough recombinant protein to immunize large animals.
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Affiliation(s)
- Sonia Pina-Pedrero
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.
| | - Àlex Olvera
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
| | - Albert Bensaid
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
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Abstract
Type V secretion denotes a variety of secretion systems that cross the outer membrane in Gram-negative bacteria but that depend on the Sec machinery for transport through the inner membrane. They are possibly the simplest bacterial secretion systems, because they consist only of a single polypeptide chain (or two chains in the case of two-partner secretion). Their seemingly autonomous transport through the outer membrane has led to the term "autotransporters" for various subclasses of type V secretion. In this chapter, we review the structure and function of these transporters and review recent findings on additional factors involved in the secretion process, which have put the term "autotransporter" to debate.
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Mühlenkamp MC, Hallström T, Autenrieth IB, Bohn E, Linke D, Rinker J, Riesbeck K, Singh B, Leo JC, Hammerschmidt S, Zipfel PF, Schütz MS. Vitronectin Binds to a Specific Stretch within the Head Region of Yersinia Adhesin A and Thereby Modulates Yersinia enterocolitica Host Interaction. J Innate Immun 2016; 9:33-51. [PMID: 27798934 DOI: 10.1159/000449200] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 08/17/2016] [Indexed: 01/02/2023] Open
Abstract
Complement resistance is an important virulence trait of Yersinia enterocolitica (Ye). The predominant virulence factor expressed by Ye is Yersinia adhesin A (YadA), which enables bacterial attachment to host cells and extracellular matrix and additionally allows the acquisition of soluble serum factors. The serum glycoprotein vitronectin (Vn) acts as an inhibitory regulator of the terminal complement complex by inhibiting the lytic pore formation. Here, we show YadA-mediated direct interaction of Ye with Vn and investigated the role of this Vn binding during mouse infection in vivo. Using different Yersinia strains, we identified a short stretch in the YadA head domain of Ye O:9 E40, similar to the 'uptake region' of Y. pseudotuberculosis YPIII YadA, as crucial for efficient Vn binding. Using recombinant fragments of Vn, we found the C-terminal part of Vn, including heparin-binding domain 3, to be responsible for binding to YadA. Moreover, we found that Vn bound to the bacterial surface is still functionally active and thus inhibits C5b-9 formation. In a mouse infection model, we demonstrate that Vn reduces complement-mediated killing of Ye O:9 E40 and, thus, improved bacterial survival. Taken together, these findings show that YadA-mediated Vn binding influences Ye pathogenesis.
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Affiliation(s)
- Melanie C Mühlenkamp
- Institute for Medical Microbiology and Hygiene, University Hospital Tübingen, Tübingen, Germany
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